Prediction of distance in hammer throwing.

PubMed

Dapena, Jesús; Gutiérrez-Dávila, Marcos; Soto, Víctor M; Rojas, Francisco J

2003-01-01

The aim of this study was to determine how much the predicted distance of a hammer throw is affected by (1) ignoring air resistance and (2) assuming that the centre of mass of the hammer coincides with the centre of the ball. Three-dimensional data from actual throws (men: 72.82 +/- 7.43 m; women: 67.78 +/- 4.02 m) were used to calculate the kinematic conditions of the hammer at release. A mathematical model of the hammer was then used to simulate the three-dimensional airborne motion of the hammer and to predict the distance of the throw. The distance predicted for vacuum conditions and using the ball centre to represent the hammer centre of mass was 4.30 +/- 2.64 m longer than the official distance of the throw for the men and 8.82 +/- 3.20 m longer for the women. Predictions using the true centre of mass of the hammer reduced the discrepancy to 2.39 +/- 2.58 m for the men and 5.28 +/- 2.88 m for the women. Predictions using air resistance and the true centre of mass of the hammer further reduced the discrepancy to -0.46 +/- 2.63 m for the men and 1.16 +/- 2.31 m for the women. Approximately half the loss of distance produced by air resistance was due to forces made on the ball and the remainder to forces made on the cable and handle. Equations were derived for calculation of the effects of air resistance and of the assumption that the centre of mass of the hammer coincides with the centre of the ball, on the distance of the throw.

Dead-blow hammer design applied to a calibration target mechanism to dampen excessive rebound

NASA Technical Reports Server (NTRS)

Lim, Brian Y.

1991-01-01

An existing rotary electromagnetic driver was specified to be used to deploy and restow a blackbody calibration target inside of a spacecraft infrared science instrument. However, this target was much more massive than any other previously inherited design applications. The target experienced unacceptable bounce when reaching its stops. Without any design modification, the momentum generated by the driver caused the target to bounce back to its starting position. Initially, elastomeric dampers were used between the driver and the target. However, this design could not prevent the bounce, and it compromised the positional accuracy of the calibration target. A design that successfully met all the requirements incorporated a sealed pocket 85 percent full of 0.75 mm diameter stainless steel balls in the back of the target to provide the effect of a dead-blow hammer. The energy dissipation resulting from the collision of balls in the pocket successfully dampened the excess momentum generated during the target deployment. The disastrous effects of new requirements on a design with a successful flight history, the modifications that were necessary to make the device work, and the tests performed to verify its functionality are described.

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Arnis Judzis

2002-10-01

This document details the progress to date on the OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE -- A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING contract for the quarter starting July 2002 through September 2002. Even though we are awaiting the optimization portion of the testing program, accomplishments include the following: (1) Smith International agreed to participate in the DOE Mud Hammer program. (2) Smith International chromed collars for upcoming benchmark tests at TerraTek, now scheduled for 4Q 2002. (3) ConocoPhillips had a field trial of the Smith fluid hammer offshore Vietnam. The hammer functioned properly, though themore » well encountered hole conditions and reaming problems. ConocoPhillips plan another field trial as a result. (4) DOE/NETL extended the contract for the fluid hammer program to allow Novatek to ''optimize'' their much delayed tool to 2003 and to allow Smith International to add ''benchmarking'' tests in light of SDS Digger Tools' current financial inability to participate. (5) ConocoPhillips joined the Industry Advisors for the mud hammer program. (6) TerraTek acknowledges Smith International, BP America, PDVSA, and ConocoPhillips for cost-sharing the Smith benchmarking tests allowing extension of the contract to complete the optimizations.« less

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Arnis Judzis

2003-07-01

This document details the progress to date on the ''OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING'' contract for the quarter starting April 2003 through June 2003. The DOE and TerraTek continue to wait for Novatek on the optimization portion of the testing program (they are completely rebuilding their fluid hammer). Accomplishments included the following: (1) Hughes Christensen has recently expressed interest in the possibility of a program to examine cutter impact testing, which would be useful in a better understanding of the physics of rock impact. Their interest however is notmore » necessarily fluid hammers, but to use the information for drilling bit development. (2) Novatek (cost sharing supplier of tools) has informed the DOE project manager that their tool may not be ready for ''optimization'' testing late summer 2003 (August-September timeframe) as originally anticipated. During 3Q Novatek plans to meet with TerraTek to discuss progress with their tool for 4Q 2003 testing. (3) A task for an addendum to the hammer project related to cutter impact studies was written during 2Q 2003. (4) Smith International internally is upgrading their hammer for the optimization testing phase. One currently known area of improvement is their development program to significantly increase the hammer blow energy.« less

When suppressing one stereotype leads to rebound of another: on the procedural nature of stereotype rebound.

PubMed

Geeraert, Nicolas

2013-09-01

A known consequence of stereotype suppression is post-suppressional rebound (PSR), an ironic activation of the suppressed stereotype. This is typically explained as an unintended by-product from a dual-process model of mental control. Relying on this model, stereotype rebound is believed to be conceptual. Alternative accounts predict PSR to be featural or procedural. According to the latter account, stereotype rebound would not be limited to the suppressed social category, but could occur for a target from any social category. The occurrence of procedural stereotype rebound was examined across five experiments. Suppression of one particular stereotype consistently led to rebound for social targets belonging to the same or a different stereotype in an essay-writing task (Experiments 1-3) and led to facilitation in recognition of stereotype-consistent words (Experiment 4). Finally, stereotype suppression was shown to impact on assessments of stereotype use but not on heuristic thinking (Experiment 5).

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Arnis Judzis

2004-04-01

This document details the progress to date on the OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING contract for the quarter starting January 2004 through March 2004. The DOE and TerraTek continue to wait for Novatek on the optimization portion of the testing program (they are completely rebuilding their fluid hammer). The latest indication is that the Novatek tool would be ready for retesting only 3Q 2004. Smith International's hammer will be tested in April of 2004 (2Q 2004 report). Accomplishments included the following: (1) TerraTek presented a paper for publication inmore » conjunction with a peer review at the GTI Natural Gas Technologies Conference February 10, 2004. Manuscripts and associated presentation material were delivered on schedule. The paper was entitled ''Mud Hammer Performance Optimization''. (2) Shell Exploration and Production continued to express high interest in the ''cutter impact'' testing program Task 8. Hughes Christensen supplied inserts for this testing program. (3) TerraTek hosted an Industry/DOE planning meeting to finalize a testing program for ''Cutter Impact Testing--Understanding Rock Breakage with Bits'' on February 13, 2004. (4) Formal dialogue with Terralog was initiated. Terralog has recently been awarded a DOE contract to model hammer mechanics with TerraTek as a sub-contractor. (5) Novatek provided the DOE with a schedule to complete their new fluid hammer and test it at TerraTek.« less

Rebound hyperglycaemia in diabetic cats.

PubMed

Roomp, Kirsten; Rand, Jacquie

2016-08-01

Rebound hyperglycaemia (also termed Somogyi effect) is defined as hyperglycaemia caused by the release of counter-regulatory hormones in response to insulin-induced hypoglycaemia, and is widely believed to be common in diabetic cats. However, studies in human diabetic patients over the past quarter century have rejected the common occurrence of this phenomenon. Therefore, we evaluated the occurrence and prevalence of rebound hyperglycaemia in diabetic cats. In a retrospective study, 10,767 blood glucose curves of 55 cats treated with glargine using an intensive blood glucose regulation protocol with a median of five blood glucose measurements per day were evaluated for evidence of rebound hyperglycaemic events, defined in two different ways (with and without an insulin resistance component). While biochemical hypoglycaemia occurred frequently, blood glucose curves consistent with rebound hyperglycaemia with insulin resistance was confined to four single events in four different cats. In 14/55 cats (25%), a median of 1.5% (range 0.32-7.7%) of blood glucose curves were consistent with rebound hyperglycaemia without an insulin resistance component; this represented 0.42% of blood glucose curves in both affected and unaffected cats. We conclude that despite the frequent occurrence of biochemical hypoglycaemia, rebound hyperglycaemia is rare in cats treated with glargine on a protocol aimed at tight glycaemic control. For glargine-treated cats, insulin dose should not be reduced when there is hyperglycaemia in the absence of biochemical or clinical evidence of hypoglycaemia. © ISFM and AAFP 2015.

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Alan Black; Arnis Judzis

2003-01-01

Progress during current reporting year 2002 by quarter--Progress during Q1 2002: (1) In accordance to Task 7.0 (D. No.2 Technical Publications) TerraTek, NETL, and the Industry Contributors successfully presented a paper detailing Phase 1 testing results at the February 2002 IADC/SPE Drilling Conference, a prestigious venue for presenting DOE and private sector drilling technology advances. The full reference is as follows: IADC/SPE 74540 ''World's First Benchmarking of Drilling Mud Hammer Performance at Depth Conditions'' authored by Gordon A. Tibbitts, TerraTek; Roy C. Long, US Department of Energy, Brian E. Miller, BP America, Inc.; Arnis Judzis, TerraTek; and Alan D. Black,more » TerraTek. Gordon Tibbitts, TerraTek, will presented the well-attended paper in February of 2002. The full text of the Mud Hammer paper was included in the last quarterly report. (2) The Phase 2 project planning meeting (Task 6) was held at ExxonMobil's Houston Greenspoint offices on February 22, 2002. In attendance were representatives from TerraTek, DOE, BP, ExxonMobil, PDVSA, Novatek, and SDS Digger Tools. (3) PDVSA has joined the advisory board to this DOE mud hammer project. PDVSA's commitment of cash and in-kind contributions were reported during the last quarter. (4) Strong Industry support remains for the DOE project. Both Andergauge and Smith Tools have expressed an interest in participating in the ''optimization'' phase of the program. The potential for increased testing with additional Industry cash support was discussed at the planning meeting in February 2002. Progress during Q2 2002: (1) Presentation material was provided to the DOE/NETL project manager (Dr. John Rogers) for the DOE exhibit at the 2002 Offshore Technology Conference. (2) Two meeting at Smith International and one at Andergauge in Houston were held to investigate their interest in joining the Mud Hammer Performance study. (3) SDS Digger Tools (Task 3 Benchmarking participant) apparently has not negotiated

Drop rebound after impact: the role of the receding contact angle.

PubMed

Antonini, C; Villa, F; Bernagozzi, I; Amirfazli, A; Marengo, M

2013-12-31

Data from the literature suggest that the rebound of a drop from a surface can be achieved when the wettability is low, i.e., when contact angles, measured at the triple line (solid-liquid-air), are high. However, no clear criterion exists to predict when a drop will rebound from a surface and which is the key wetting parameter to govern drop rebound (e.g., the "equilibrium" contact angle, θeq, the advancing and the receding contact angles, θA and θR, respectively, the contact angle hysteresis, Δθ, or any combination of these parameters). To clarify the conditions for drop rebound, we conducted experimental tests on different dry solid surfaces with variable wettability, from hydrophobic to superhydrophobic surfaces, with advancing contact angles 108° < θA < 169° and receding contact angles 89° < θR < 161°. It was found that the receding contact angle is the key wetting parameter that influences drop rebound, along with surface hydrophobicity: for the investigated impact conditions (drop diameter 2.4 < D0 < 2.6 mm, impact speed 0.8 < V < 4.1 m/s, Weber number 25 < We < 585), rebound was observed only on surfaces with receding contact angles higher than 100°. Also, the drop rebound time decreased by increasing the receding contact angle. It was also shown that in general care must be taken when using statically defined wetting parameters (such as advancing and receding contact angles) to predict the dynamic behavior of a liquid on a solid surface because the dynamics of the phenomenon may affect surface wetting close to the impact point (e.g., as a result of the transition from the Cassie-Baxter to Wenzel state in the case of the so-called superhydrophobic surfaces) and thus affect the drop rebound.

Geodesy: Modeling Earth's Post-Glacial Rebound

NASA Astrophysics Data System (ADS)

Spada, Giorgio; Antonioli, Andrea; Boschi, Lapo; Brandi, Valter; Cianetti, Spina; Galvani, Gabriele; Giunchi, Carlo; Perniola, Bruna; Agostinetti, Nicola Piana; Piersanti, Antonio; Stocchi, Paolo

2004-02-01

Efforts to mathematically model the Earth's post-glacial rebound, or, in general, long-term planetary-scale viscoelastic deformations, have been ongoing for several decades. Unfortunately, research in the post-glacial rebound community has not been characterized by much exchange of knowledge. Groups around the world have developed their code independently, sometimes with profoundly different approaches, occasionally leading to inconsistent results [e.g., Boschi et al., 1999]. Postglacial Rebound Calculator (TABOO) is a post-glacial rebound software that is being made freely available (through Samizdat Press at http://samizdat.mines.edu/taboo/)in the hope that it might become a common reference for all post-glacial rebound researchers. TABOO is portable and has been tested on Unix, Linux, and Windows systems; all it requires is a Fortran90 compiler supporting quadruple precision. The software is easy to use. It comes with a detailed guide that can work as a quick reference cookbook, and it is also accompanied by a textbook, The Theory Behind TABOO, collecting the most significant theoretical results from post-glacial rebound literature. TABOO is not a ``black-box,'' although it may easily be used as such. The entire source code is provided and should be easy to understand for intermediate-level Fortran programmers.

Unique perceptuomotor control of stone hammers in wild monkeys.

PubMed

Mangalam, Madhur; Pacheco, Matheus Maia; Izar, Patrícia; Visalberghi, Elisabetta; Fragaszy, Dorothy Munkenbeck

2018-01-01

We analysed the patterns of coordination of striking movement and perceptuomotor control of stone hammers in wild bearded capuchin monkeys, Sapajus libidinosus as they cracked open palm nut using hammers of different mass, a habitual behaviour in our study population. We aimed to determine why these monkeys cannot produce conchoidally fractured flakes as do contemporary human knappers or as did prehistoric hominin knappers. We found that the monkeys altered their patterns of coordination of movement to accommodate changes in hammer mass. By altering their patterns of coordination, the monkeys kept the strike's amplitude and the hammer's velocity at impact constant with respect to hammer mass. In doing so, the hammer's kinetic energy at impact-which determines the propagation of a fracture/crack in a nut-varied across hammers of different mass. The monkeys did not control the hammer's kinetic energy at impact, the key parameter a perceiver-actor should control while knapping stones. These findings support the hypothesis that the perceptuomotor control of stone hammers in wild bearded capuchin monkeys is inadequate to produce conchoidally fractured flakes by knapping stones, as do humans. © 2018 The Author(s).

Rebound Headaches

MedlinePlus

... relievers. Common pain relievers such as aspirin and acetaminophen (Tylenol, others) may contribute to rebound headaches — especially ... OTC) pain relievers that combine caffeine, aspirin and acetaminophen (Excedrin, others) are common culprits. This group also ...

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Gordon Tibbitts; Arnis Judzis

2002-07-01

This document details the progress to date on the OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE -- A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING contract for the quarter starting April 2002 through June 2002. Even though we are awaiting the optimization portion of the testing program, accomplishments include the following: (1) Presentation material was provided to the DOE/NETL project manager (Dr. John Rogers) for the DOE exhibit at the 2002 Offshore Technology Conference. (2) Two meeting at Smith International and one at Andergauge in Houston were held to investigate their interest in joining the Mud Hammer Performancemore » study. (3) SDS Digger Tools (Task 3 Benchmarking participant) apparently has not negotiated a commercial deal with Halliburton on the supply of fluid hammers to the oil and gas business. (4) TerraTek is awaiting progress by Novatek (a DOE contractor) on the redesign and development of their next hammer tool. Their delay will require an extension to TerraTek's contracted program. (5) Smith International has sufficient interest in the program to start engineering and chroming of collars for testing at TerraTek. (6) Shell's Brian Tarr has agreed to join the Industry Advisory Group for the DOE project. The addition of Brian Tarr is welcomed as he has numerous years of experience with the Novatek tool and was involved in the early tests in Europe while with Mobil Oil. (7) Conoco's field trial of the Smith fluid hammer for an application in Vietnam was organized and has contributed to the increased interest in their tool.« less

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Arnis Judzis

2004-07-01

This document details the progress to date on the ''OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING'' contract for the quarter starting April 2004 through June 2004. The DOE and TerraTek continue to wait for Novatek on the optimization portion of the testing program (they are completely rebuilding their fluid hammer). The latest indication is that the Novatek tool would be ready for retesting only 4Q 2004 or later. Smith International's hammer was tested in April of 2004 (2Q 2004 report). Accomplishments included the following: (1) TerraTek re-tested the ''optimized'' fluid hammermore » provided by Smith International during April 2004. Many improvements in mud hammer rates of penetration were noted over Phase 1 benchmark testing from November 2002. (2) Shell Exploration and Production in The Hague was briefed on various drilling performance projects including Task 8 ''Cutter Impact Testing''. Shell interest and willingness to assist in the test matrix as an Industry Advisor is appreciated. (3) TerraTek participated in a DOE/NETL Review meeting at Morgantown on April 15, 2004. The discussions were very helpful and a program related to the Mud Hammer optimization project was noted--Terralog modeling work on percussion tools. (4) Terralog's Dr. Gang Han witnessed some of the full-scale optimization testing of the Smith International hammer in order to familiarize him with downhole tools. TerraTek recommends that modeling first start with single cutters/inserts and progress in complexity. (5) The final equipment problem on the impact testing task was resolved through the acquisition of a high data rate laser based displacement instrument. (6) TerraTek provided Novatek much engineering support for the future re-testing of their optimized tool. Work was conducted on slip ring [electrical] specifications and tool collar sealing in the testing vessel with a reconfigured flow system on Novatek's collar.« less

Development of a Piezoelectric Rotary Hammer Drill

NASA Technical Reports Server (NTRS)

Domm, Lukas N.

2011-01-01

The Piezoelectric Rotary Hammer Drill is designed to core through rock using a combination of rotation and high frequency hammering powered by a single piezoelectric actuator. It is designed as a low axial preload, low mass, and low power device for sample acquisition on future missions to extraterrestrial bodies. The purpose of this internship is to develop and test a prototype of the Piezoelectric Rotary Hammer Drill in order to verify the use of a horn with helical or angled cuts as a hammering and torque inducing mechanism. Through an iterative design process using models in ANSYS Finite Element software and a Mason's Equivalent Circuit model in MATLAB, a horn design was chosen for fabrication based on the predicted horn tip motion, electromechanical coupling, and neutral plane location. The design was then machined and a test bed assembled. The completed prototype has proven that a single piezoelectric actuator can be used to produce both rotation and hammering in a drill string through the use of a torque inducing horn. Final data results include bit rotation produced versus input power, and best drilling rate achieved with the prototype.

Simulation of low pressure water hammer

NASA Astrophysics Data System (ADS)

Himr, D.; Habán, V.

2010-08-01

Numerical solution of water hammer is presented in this paper. The contribution is focused on water hammer in the area of low pressure, which is completely different than high pressure case. Little volume of air and influence of the pipe are assumed in water, which cause sound speed change due to pressure alterations. Computation is compared with experimental measurement.

Optimization of Mud Hammer Drilling Performance--A Program to Benchmark the Viability of Advanced Mud Hammer Drilling

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

Arnis Judzis

2006-03-01

Operators continue to look for ways to improve hard rock drilling performance through emerging technologies. A consortium of Department of Energy, operator and industry participants put together an effort to test and optimize mud driven fluid hammers as one emerging technology that has shown promise to increase penetration rates in hard rock. The thrust of this program has been to test and record the performance of fluid hammers in full scale test conditions including, hard formations at simulated depth, high density/high solids drilling muds, and realistic fluid power levels. This paper details the testing and results of testing two 7more » 3/4 inch diameter mud hammers with 8 1/2 inch hammer bits. A Novatek MHN5 and an SDS Digger FH185 mud hammer were tested with several bit types, with performance being compared to a conventional (IADC Code 537) tricone bit. These tools functionally operated in all of the simulated downhole environments. The performance was in the range of the baseline ticone or better at lower borehole pressures, but at higher borehole pressures the performance was in the lower range or below that of the baseline tricone bit. A new drilling mode was observed, while operating the MHN5 mud hammer. This mode was noticed as the weight on bit (WOB) was in transition from low to high applied load. During this new ''transition drilling mode'', performance was substantially improved and in some cases outperformed the tricone bit. Improvements were noted for the SDS tool while drilling with a more aggressive bit design. Future work includes the optimization of these or the next generation tools for operating in higher density and higher borehole pressure conditions and improving bit design and technology based on the knowledge gained from this test program.« less

The Physics of Pollen and Spore Rebound from Plant Surfaces.

NASA Astrophysics Data System (ADS)

Paw U, Kyaw Tha

1980-12-01

The problem of particle rebound from plant surfaces has been examined. Particle rebound is a component of net deposition; the other components are reentrainment and impingement. I carried out several sets of wind tunnel experiments to examine the nature of rebound, reentrainment and impingement. Quantitative and qualitative analyses were carried out on the data. A simple computer model was created to predict particle deposition in wind tunnel conditions. My work confirms that rebound is an important process in the wind tunnel, and implies the existence of a process I call 'rebound/reentrainment'. I tested several major hypotheses. The first was that biological materials exhibit the same physical rebound characteristics as artificial materials. The second was that particles rebound in a manner predicted by Dahneke's (1971, 1975) theory. The third was that rebound is a dominant component of net deposition. The fourth was that surface characteristics may seriously influence rebound. I carried out my experiments in a low-speed wind tunnel. For surfaces I used glass and the leaves of tulip poplar (Liriodendron tulipifera), Coleus (Coleus blumeii) and American elm (Ulmus americana). For particles I used glass microbeads, lycopodium spores (Lycopodium spp.), and ragweed pollen (Ambrosia trifida). Four main sets of experiments were carried out. I examined rebound, as a function of particle speed, of particles impinging upon leaf surfaces, reentrainment of spores and pollen as a function of wind speed and time, net deposition, as a function of wind speed, and adhesion of pollen and spores to the leaf surfaces. From these experiments I concluded that in general, pollen and spore rebound can be described well by Dahneke's (1971, 1975) theory. Particle differences are far more significant than surface differences in the rebound process. I postulate the existence of rebound/reentrainment when particles impinge on surfaces with tangential fluid flow present. Particles will

Infrasound Generation from the HH Seismic Hammer.

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

Jones, Kyle Richard

2014-10-01

The HH Seismic hammer is a large, "weight-drop" source for active source seismic experiments. This system provides a repetitive source that can be stacked for subsurface imaging and exploration studies. Although the seismic hammer was designed for seismological studies it was surmised that it might produce energy in the infrasonic frequency range due to the ground motion generated by the 13 metric ton drop mass. This study demonstrates that the seismic hammer generates a consistent acoustic source that could be used for in-situ sensor characterization, array evaluation and surface-air coupling studies for source characterization.

Effect of hammer mass on upper extremity joint moments.

PubMed

Balendra, Nilanthy; Langenderfer, Joseph E

2017-04-01

This study used an OpenSim inverse-dynamics musculoskeletal model scaled to subject-specific anthropometrics to calculate three-dimensional intersegmental moments at the shoulder, elbow and wrist while 10 subjects used 1 and 2 lb hammers to drive nails. Motion data were collected via an optoelectronic system and the interaction of the hammer with nails was recorded with a force plate. The larger hammer caused substantial increases (50-150%) in moments, although increases differed by joint, anatomical component, and significance of the effect. Moment increases were greater in cocking and strike/follow-through phases as opposed to swinging and may indicate greater potential for injury. Compared to shoulder, absolute increases in peak moments were smaller for elbow and wrist, but there was a trend toward larger relative increases for distal joints. Shoulder rotation, elbow varus-valgus and pronation-supination, and wrist radial-ulnar deviation and rotation demonstrated large relative moment increases. Trial and phase durations were greater for the larger hammer. Changes in moments and timing indicate greater loads on musculoskeletal tissues for an extended period with the larger hammer. Additionally, greater variability in timing with the larger hammer, particularly for cocking phase, suggests differences in control of the motion. Increased relative moments for distal joints may be particularly important for understanding disorders of the elbow and wrist associated with hammer use. Copyright © 2016 Elsevier Ltd. All rights reserved.

View of hammer nameplate (Chambersburg Engineering Company, Chambersburg, Penna USA) ...

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

View of hammer nameplate (Chambersburg Engineering Company, Chambersburg, Penna USA) and view north of Tony Talotta (heavy forger), Paul Azcharka (hammer operator), and Morty Hoffman (hammer operator helper) forging eyebolts. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

WATER HAMMER OSCILLATIONS IN THE IRRIGATION FACILITIES

NASA Astrophysics Data System (ADS)

Kurata, Kouichi; Sasaki, Katsuhito; Makihata, Toshiaki

In case a gate installed at the end of discharge conduit is vibrating during discharge, or an air valve is vibrating during water-filling operation into the conduit pipe between main gate and auxiliary gate, and vibration period tv is larger than tc (water hammer propagation time) that is equivalent to the phenomenon of slow closure, there is a possibility that water hammer oscillation in the discharge conduit could be induced. In this paper, by using two case examples, vibration phenomena transmitted to each part are analyzed, on the basis of water pressure fluctuation and pressure wave propagation due to occurrence of water hammer oscillation.

Rebounding of a shaped-charge jet

NASA Astrophysics Data System (ADS)

Proskuryakov, E. V.; Sorokin, M. V.; Fomin, V. M.

2007-09-01

The phenomenon of rebounding of a shaped-charge jet from the armour surface with small angles between the jet axis and the target surface is considered. Rebounding angles as a function of jet velocity are obtained in experiments for a copper shaped-charge jet. An engineering calculation technique is developed. The results calculated with the use of this technique are in reasonable agreement with experimental data.

Pump-stopping water hammer simulation based on RELAP5

NASA Astrophysics Data System (ADS)

Yi, W. S.; Jiang, J.; Li, D. D.; Lan, G.; Zhao, Z.

2013-12-01

RELAP5 was originally designed to analyze complex thermal-hydraulic interactions that occur during either postulated large or small loss-of-coolant accidents in PWRs. However, as development continued, the code was expanded to include many of the transient scenarios that might occur in thermal-hydraulic systems. The fast deceleration of the liquid results in high pressure surges, thus the kinetic energy is transformed into the potential energy, which leads to the temporary pressure increase. This phenomenon is called water hammer. Generally water hammer can occur in any thermal-hydraulic systems and it is extremely dangerous for the system when the pressure surges become considerably high. If this happens and when the pressure exceeds the critical pressure that the pipe or the fittings along the pipeline can burden, it will result in the failure of the whole pipeline integrity. The purpose of this article is to introduce the RELAP5 to the simulation and analysis of water hammer situations. Based on the knowledge of the RELAP5 code manuals and some relative documents, the authors utilize RELAP5 to set up an example of water-supply system via an impeller pump to simulate the phenomena of the pump-stopping water hammer. By the simulation of the sample case and the subsequent analysis of the results that the code has provided, we can have a better understand of the knowledge of water hammer as well as the quality of the RELAP5 code when it's used in the water-hammer fields. In the meantime, By comparing the results of the RELAP5 based model with that of other fluid-transient analysis software say, PIPENET. The authors make some conclusions about the peculiarity of RELAP5 when transplanted into water-hammer research and offer several modelling tips when use the code to simulate a water-hammer related case.

14 CFR 25.487 - Rebound landing condition.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rebound landing condition. 25.487 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.487 Rebound landing condition. (a) The landing gear and its supporting structure must be investigated for the loads occurring during...

14 CFR 25.487 - Rebound landing condition.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Rebound landing condition. 25.487 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.487 Rebound landing condition. (a) The landing gear and its supporting structure must be investigated for the loads occurring during...

Vibration and recoil control of pneumatic hammers. [by air flow pressure regulation

NASA Technical Reports Server (NTRS)

Constantinescu, I. N.; Darabont, A. V.

1974-01-01

Vibration sources are described for pneumatic hammers used in the mining industry (pick hammers), in boiler shops (riveting hammers), etc., bringing to light the fact that the principal vibration source is the variation in air pressure inside the cylinder. The present state of the art of vibration control of pneumatic hammers as it is practiced abroad, and the solutions adopted for this purpose, are discussed. A new type of pneumatic hammer with a low noise and vibration level is presented.

A case study on stratified settlement and rebound characteristics due to dewatering in Shanghai subway station.

PubMed

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-01-01

Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR) of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed.

A Case Study on Stratified Settlement and Rebound Characteristics due to Dewatering in Shanghai Subway Station

PubMed Central

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-01-01

Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR) of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed. PMID:23878521

Evaluation of a rebound tonometer (Tonovet) in clinically normal cat eyes.

PubMed

Rusanen, Elina; Florin, Marion; Hässig, Michael; Spiess, Bernhard M

2010-01-01

To determine the accuracy of and to establish reference values for a rebound tonometer (Tonovet) in normal feline eyes, to compare it with an applanation tonometer (Tonopen Vet) and to evaluate the effect of topical anesthesia on rebound tonometry. Six enucleated eyes were used to compare both tonometers with direct manometry. Intraocular pressure (IOP) was measured in 100 cats to establish reference values for rebound tonometry. Of these, 22 cats were used to compare rebound tonometry with and without topical anesthesia and 33 cats to compare the rebound and applanation tonometers. All evaluated eyes were free of ocular disease. Both tonometers correlated well with direct manometry. The best agreement with the rebound tonometer was achieved between 25-50 mmHg. The applanation tonometer was accurate at pressures between 0 and 30 mmHg. The mean IOP in clinically normal cats was 20.74 mmHg with the rebound tonometer and 18.4 mmHg with the applanation tonometer. Topical anesthesia did not significantly affect rebound tonometry. As the rebound tonometer correlated well with direct manometry in the clinically important pressure range and was well tolerated by cats, it appears suitable for glaucoma diagnosis. The mean IOP obtained with the rebound tonometer was 2-3 mmHg higher than that measured with the applanation tonometer. This difference is within clinically acceptable limits, but indicates that the same type of tonometer should be used in follow-up examinations in a given cat.

The Schmidt hammer as a relative-age dating tool and its potential for calibrated-age dating in Holocene glaciated environments

NASA Astrophysics Data System (ADS)

Shakesby, Richard A.; Matthews, John A.; Owen, Geraint

2006-11-01

The Schmidt hammer is a relatively cheap, portable, sturdy instrument with proven value over the last two decades or so in rapidly dating coarse inorganic deposits of diverse origins. Early views were that its dating role was limited to distinguishing recently exposed from much older. Typically, either a few sites of possibly different ages or occasional older surfaces amongst many young sites were studied. More recently, calibration curves based on individual R-value means from small numbers (2-4) of sites of known ages have been used to estimate the ages of undated sites. We present Schmidt hammer rebound ( R-) values from 28 'Little Ice Age' (and younger), 23 Preboreal and 7 Younger Dryas glaciated surfaces in southern Norway in order, first, to test rigorously the robustness of the instrument as a relative-age dating tool. Despite being obtained from different surfaces (moraines, glaciofluvial deposits and bedrock) and varied metamorphic lithologies, the R-value overall means and 95% confidence intervals for the 'Little Ice Age', Preboreal and Younger Dryas age categories (respectively, 60.0±1.6, 41.6±1.4 and 34.2±2.0) are statistically significantly different. Only two outlying sites in the two younger age categories have overlapping confidence intervals, demonstrating remarkable robustness in differentiating early- and late-Holocene surfaces. The distinction between Preboreal and Younger Dryas sites (with terminal dates <2000 years apart) is less clear but still statistically significant, though possibly partly because of enhanced weathering conditions at the predominantly well vegetated Younger Dryas sites. Second, we examine the feasibility and desirability of controlling non-age-related factors, including some previously considered critical (instrument wear, operator bias, initial rock surface texture), which emerge either as less important than previously argued or as relatively unimportant, together with others previously unreported (e.g. long

Auto-Gopher: A Wire-Line Rotary-Hammer Ultrasonic Drill

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Sherrit, Stewart; Bao, Xiaogi; Bar-Cohen, Yoseph; Chen, Beck

2011-01-01

Developing technologies that would enable NASA to sample rock, soil, and ice by coring, drilling or abrading at a significant depth is of great importance for a large number of in-situ exploration missions as well as for earth applications. Proven techniques to sample Mars subsurface will be critical for future NASA astrobiology missions that will search for records of past and present life on the planet, as well as, the search for water and other resources. A deep corer, called Auto-Gopher, is currently being developed as a joint effort of the JPL's NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher is a wire-line rotary-hammer drill that combines rock breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) that has been developed as an adaptable tool for many of drilling and coring applications. The USDC uses an intermediate free-flying mass to transform the high frequency vibrations of the horn tip into a sonic hammering of a drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher. The lessons learned from testing the ice gopher were implemented into the design of the Auto-Gopher by inducing a rotary motion onto the fluted coring bit. A wire-line version of such a system would allow penetration of significant depth without a large increase in mass. A laboratory version of the corer was developed in the NDEAA lab to determine the design and drive parameters of the integrated system. The design configuration lab version of the design and fabrication and preliminary testing results are presented in this paper

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Gordon Tibbitts; Arnis Judzis

2002-04-01

This document details the progress to date on the OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE--A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING contract for the quarter starting January 2002 through March 2002. Accomplishments include the following: In accordance to Task 7.0 (D. No.2 Technical Publications) TerraTek, NETL, and the Industry Contributors successfully presented a paper detailing Phase 1 testing results at the February 2002 IADC/SPE Drilling Conference, a prestigious venue for presenting DOE and private sector drilling technology advances. The full reference is as follows: (1) IADC/SPE 74540 ''World's First Benchmarking of Drilling Mud Hammer Performance atmore » Depth Conditions'' authored by Gordon A. Tibbitts, TerraTek; Roy C. Long, US Department of Energy, Brian E. Miller, BP America, Inc.; Arnis Judzis, TerraTek; and Alan D. Black, TerraTek. Gordon Tibbitts, TerraTek, will presented the well-attended paper in February of 2002. The full text of the Mud Hammer paper was included in the last quarterly report. (2) The Phase 2 project planning meeting (Task 6) was held at ExxonMobil's Houston Greenspoint offices on February 22, 2002. In attendance were representatives from TerraTek, DOE, BP, ExxonMobil, PDVSA, Novatek, and SDS Digger Tools. (3) PDVSA has joined the advisory board to this DOE mud hammer project. PDVSA's commitment of cash and in-kind contributions were reported during the last quarter. (4) Strong Industry support remains for the DOE project. Both Andergauge and Smith Tools have expressed an interest in participating in the ''optimization'' phase of the program. The potential for increased testing with additional Industry cash support was discussed at the planning meeting in February 2002.« less

Exchange rate rebounds after foreign exchange market interventions

NASA Astrophysics Data System (ADS)

Hoshikawa, Takeshi

2017-03-01

This study examined the rebounds in the exchange rate after foreign exchange intervention. When intervention is strongly effective, the exchange rate rebounds at next day. The effect of intervention is reduced slightly by the rebound after the intervention. The exchange rate might have been 67.12-77.47 yen to a US dollar without yen-selling/dollar-purchasing intervention of 74,691,100 million yen implemented by the Japanese government since 1991, in comparison to the actual exchange rate was 103.19 yen to the US dollar at the end of March 2014.

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Gordon Tibbitts; Arnis Judzis

2001-10-01

This document details the progress to date on the OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE -- A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING contract for the quarter starting July 2001 through September 2001. Accomplishments to date include the following: TerraTek highlighted DOE's National Energy Technology Laboratory effort on Mud Hammer Optimization at the recent Annual Conference and Exhibition for the Society of Petroleum Engineers. The original exhibit scheduled by NETL was canceled due to events surrounding the September tragedies in the US. TerraTek has completed analysis of drilling performance (rates of penetration, hydraulics, etc.) for themore » Phase One testing which was completed at the beginning of July. TerraTek jointly with the Industry Advisory Board for this project and DOE/NETL conducted a lessons learned meeting to transfer technology vital for the next series of performance tests. Both hammer suppliers benefited from the testing program and are committed to pursue equipment improvements and ''optimization'' in accordance with the scope of work. An abstract for a proposed publication by the society of Petroleum Engineers/International Association of Drilling Contractors jointly sponsored Drilling Conference was accepted as an alternate paper. Technology transfer is encouraged by the DOE in this program, thus plans are underway to prepare the paper for this prestigious venue.« less

Break-dance: an unusual cause of hammer syndrome.

PubMed

Schneider, Frédéric; Milesi, Ilaria; Haesler, Erik; Wicky, Stephan; Schnyder, P; Denys, Alban

2002-01-01

We report the case of a young break-dancer presenting with hammer syndrome. This syndrome has been correlated with many professional and recreational activities but this is, to our knowledge, the first description of hammer syndrome caused by break-dancing. The etiology, diagnosis and treatment modalities of this rare syndrome are considered.

Break-Dance: An Unusual Cause of Hammer Syndrome

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

Schneider, Frederic; Milesi, Ilaria; Haesler, Erik

2002-08-15

We report the case of a young break-dancer presenting with hammer syndrome. This syndrome has been correlated with many professional and recreational activities but this is, to our knowledge, the first description of hammer syndrome caused by break-dancing. The etiology, diagnosis and treatment modalities of this rare syndrome are considered.

When does tool use become distinctively human?: Hammering in young children

PubMed Central

Kahrs, Björn; Lockman, Jeffrey J.; Jung, Wendy

2013-01-01

This study examines the development of hammering within an ontogenetic and evolutionary framework using motion-capture technology. Twenty-four right-handed toddlers (19–35 months) wore reflective markers while hammering a peg into a peg-board. The study focuses on the motor characteristics that make tool use uniquely human: wrist involvement, lateralization, and handle use. Older children showed more distally controlled movements, characterized by relatively more reliance on the wrist, but only when hammering with their right hand. Greater age, use of the right hand, and more wrist involvement were associated with higher accuracy; handle use did not systematically change with age. Collectively, the results provide new insights about the emergence of hammering in young children and when hammering begins to manifest distinctively human characteristics. PMID:24128178

Do chimpanzees use weight to select hammer tools?

PubMed

Schrauf, Cornelia; Call, Josep; Fuwa, Koki; Hirata, Satoshi

2012-01-01

The extent to which tool-using animals take into account relevant task parameters is poorly understood. Nut cracking is one of the most complex forms of tool use, the choice of an adequate hammer being a critical aspect in success. Several properties make a hammer suitable for nut cracking, with weight being a key factor in determining the impact of a strike; in general, the greater the weight the fewer strikes required. This study experimentally investigated whether chimpanzees are able to encode the relevance of weight as a property of hammers to crack open nuts. By presenting chimpanzees with three hammers that differed solely in weight, we assessed their ability to relate the weight of the different tools with their effectiveness and thus select the most effective one(s). Our results show that chimpanzees use weight alone in selecting tools to crack open nuts and that experience clearly affects the subjects' attentiveness to the tool properties that are relevant for the task at hand. Chimpanzees can encode the requirements that a nut-cracking tool should meet (in terms of weight) to be effective.

Small head circumference at birth and early age at adiposity rebound.

PubMed

Eriksson, J G; Kajantie, E; Lampl, M; Osmond, C; Barker, D J P

2014-01-01

The adiposity rebound is the age in childhood when body mass index is at a minimum before increasing again. The age at rebound is highly variable. An early age is associated with increased obesity in later childhood and adult life. We have reported that an early rebound is predicted by low weight gain between birth and 1 year of age and resulting low body mass index at 1 year. Here, we examine whether age at adiposity rebound is determined by influences during infancy or is a consequence of foetal growth. Our hypothesis was that measurements of body size at birth are related to age at adiposity rebound. Longitudinal study of 2877 children born in Helsinki, Finland, during 1934-1944. Early age at adiposity rebound was associated with small head circumference and biparietal diameter at birth, but not with other measurements of body size at birth. The mean age at adiposity rebound rose from 5.8 years in babies with a head circumference of ≤33 cm to 6.2 in babies with a head circumference of >36 cm (P for trend = 0.007). The association between thinness in infancy and early rebound became apparent at 6 months of age. It was not associated with adverse living conditions. In a simultaneous regression, small head circumference at birth, high mother's body mass index and tall maternal stature each had statistically significant trends with early adiposity rebound (P = 0.002, <0.001, 0.004). We hypothesize that the small head size at birth that preceded an early adiposity rebound was the result of inability to sustain a rapid intra-uterine growth trajectory initiated in association with large maternal body size. This was followed by catch-up growth in infancy, and we hypothesize that this depleted the infant's fat stores. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

A body is not a metaphor: Barbara Hammer's X-ray vision.

PubMed

Osterweil, Ara

2010-01-01

This article examines three films by legendary experimental filmmaker Barbara Hammer that deal with the sick, aging, or dying body: Optic Nerve (1985), Sanctus (1990), and A Horse is Not a Metaphor (2008). By analyzing films that do not explicitly confront sexual identity, this article questions the continuing usefulness of the designation "lesbian filmmaker" when considering Hammer's diverse body of work. Tracing the "double consciousness" through which Hammer approaches the body and its construction in patriarchy-particularly in the discourse of medicine-this article argues that Hammer's is a thoroughly corporeal, but not exclusively lesbian, cinema.

The Hammer-and-Nail Phenomenon in Mathematics Education

ERIC Educational Resources Information Center

Lim, Kien H.

2012-01-01

This paper uses the hammer-and-nail metaphor to highlight the rigidity and impulsiveness that can be found in student mathematical behaviour. The hammer-and-nail phenomenon can be attributed to two plausible causes: (1) the way the human mind works; and (2) the way mathematics is traditionally taught in school. In this paper, the following aspects…

Effect of HIV Antibody VRC01 on Viral Rebound after Treatment Interruption

PubMed Central

Bar, K.J.; Sneller, M.C.; Harrison, L.J.; Justement, J.S.; Overton, E.T.; Petrone, M.E.; Salantes, D.B.; Seamon, C.A.; Scheinfeld, B.; Kwan, R.W.; Learn, G.H.; Proschan, M.A.; Kreider, E.F.; Blazkova, J.; Bardsley, M.; Refsland, E.W.; Messer, M.; Clarridge, K.E.; Tustin, N.B.; Madden, P.J.; Oden, K.S.; O’Dell, S.J.; Jarocki, B.; Shiakolas, A.R.; Tressler, R.L.; Doria-Rose, N.A.; Bailer, R.T.; Ledgerwood, J.E.; Capparelli, E.V.; Lynch, R.M.; Graham, B.S.; Moir, S.; Koup, R.A.; Mascola, J.R.; Hoxie, J.A.; Fauci, A.S.; Tebas, P.; Chun, T.-W.

2017-01-01

BACKGROUND The discovery of potent and broadly neutralizing antibodies (bNAbs) against human immunodeficiency virus (HIV) has made passive immunization a potential strategy for the prevention and treatment of HIV infection. We sought to determine whether passive administration of VRC01, a bNAb targeting the HIV CD4-binding site, can safely prevent or delay plasma viral rebound after the discontinuation of antiretroviral therapy (ART). METHODS We conducted two open-label trials (AIDS Clinical Trials Group [ACTG] A5340 and National Institutes of Health [NIH] 15-I-0140) of the safety, side-effect profile, pharmacokinetic properties, and antiviral activity of VRC01 in persons with HIV infection who were undergoing interruption of ART. RESULTS A total of 24 participants were enrolled, and one serious alcohol-related adverse event occurred. Viral rebound occurred despite plasma VRC01 concentrations greater than 50 μg per milliliter. The median time to rebound was 4 weeks in the A5340 trial and 5.6 weeks in the NIH trial. Study participants were more likely than historical controls to have viral suppression at week 4 (38% vs. 13%, P = 0.04 by a two-sided Fisher’s exact test in the A5340 trial; and 80% vs. 13%, P<0.001 by a two-sided Fisher’s exact test in the NIH trial) but the difference was not significant at week 8. Analyses of virus populations before ART as well as before and after ART interruption showed that VRC01 exerted pressure on rebounding virus, resulting in restriction of recrudescent viruses and selection for preexisting and emerging antibody neutralization–resistant virus. CONCLUSIONS VRC01 slightly delayed plasma viral rebound in the trial participants, as compared with historical controls, but it did not maintain viral suppression by week 8. In the small number of participants enrolled in these trials, no safety concerns were identified with passive immunization with a single bNAb (VRC01). (Funded by the National Institute of Allergy and

An Analysis of the Impact of Valve Closure Time on the Course of Water Hammer

NASA Astrophysics Data System (ADS)

Kodura, Apoloniusz

2016-06-01

The knowledge of transient flow in pressure pipelines is very important for the designing and describing of pressure networks. The water hammer is the most common example of transient flow in pressure pipelines. During this phenomenon, the transformation of kinetic energy into pressure energy causes significant changes in pressure, which can lead to serious problems in the management of pressure networks. The phenomenon is very complex, and a large number of different factors influence its course. In the case of a water hammer caused by valve closing, the characteristic of gate closure is one of the most important factors. However, this factor is rarely investigated. In this paper, the results of physical experiments with water hammer in steel and PE pipelines are described and analyzed. For each water hammer, characteristics of pressure change and valve closing were recorded. The measurements were compared with the results of calculations perfomed by common methods used by engineers - Michaud's equation and Wood and Jones's method. The comparison revealed very significant differences between the results of calculations and the results of experiments. In addition, it was shown that, the characteristic of butterfly valve closure has a significant influence on water hammer, which should be taken into account in analyzing this phenomenon. Comparison of the results of experiments with the results of calculations? may lead to new, improved calculation methods and to new methods to describe transient flow.

Measuring the Rebound Resilience of a Bouncing Ball

ERIC Educational Resources Information Center

Wadhwa, Ajay

2012-01-01

Some balls which are made of high-quality rubber (an elastomeric) material, such as tennis or squash balls, could be used for the determination of an important property of such materials called resilience. Since a bouncing ball involves a single impact we call this property "rebound resilience" and express it as the ratio of the rebound height to…

CFD Analysis of the Anti-Surge Effects by Water Hammering

NASA Astrophysics Data System (ADS)

Kim, Tae-oh; Jeong, Hyo-min; Chung, Han-shik; Lee, Sin-il; Lee, Kwang-sung

2015-09-01

Water hammering occurs due to the surge effect that comes from operating the pump, sudden stop during the operating due to a blackout and rapid open and close of the valve. By the water hammering of the pipeline and the pump, the valve are damaged. In this paper, transient analysis is conducted by CFD (Computational Fluid Dynamics). The purpose of this paper is to provide the research data about the change of the pressure and flow in the pipe that caused by the water hammering.

Proximal forearm extensor muscle strain is reduced when driving nails using a shock-controlled hammer.

PubMed

Buchanan, Kimberly A; Maza, Maria; Pérez-Vázquez, Carlos E; Yen, Thomas Y; Kijowski, Richard; Liu, Fang; Radwin, Robert G

2016-10-01

Repetitive hammer use has been associated with strain and musculoskeletal injuries. This study investigated if using a shock-control hammer reduces forearm muscle strain by observing adverse physiological responses (i.e. inflammation and localized edema) after use. Three matched framing hammers were studied, including a wood-handle, steel-handle, and shock-control hammer. Fifty volunteers were randomly assigned to use one of these hammers at a fatiguing pace of one strike every second, to seat 20 nails in a wood beam. Magnetic resonance imaging was used to scan the forearm muscles for inflammation before the task, immediately after hammering, and one to two days after. Electromyogram signals were measured to estimate grip exertions and localized muscle fatigue. High-speed video was used to calculate the energy of nail strikes. While estimated grip force was similar across the three hammers, the shock-control hammer had 40% greater kinetic energy upon impact and markedly less proximal extensor muscle edema than the wood-handle and steel-handle hammers, immediately after use (p<.05). Less edema observed for the shock-control hammer suggests that isolating handle shock can mitigate strain in proximal forearm extensor muscles. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rebound upbeat nystagmus after lateral gaze in episodic ataxia type 2.

PubMed

Kim, Hyo-Jung; Kim, Ji-Soo; Choi, Jae-Hwan; Shin, Jin-Hong; Choi, Kwang-Dong; Zee, David S

2014-06-01

Rebound nystagmus is a transient nystagmus that occurs on resuming the straight-ahead position after prolonged eccentric gaze. Even though rebound nystagmus is commonly associated with gaze-evoked nystagmus (GEN), development of rebound nystagmus in a different plane of gaze has not been described. We report a patient with episodic ataxia type 2 who showed transient upbeat nystagmus on resuming the straight-ahead position after sustained lateral gaze that had induced GEN and downbeat nystagmus. The rebound upbeat nystagmus may be ascribed to a shifting null in the vertical plane as a result of an adaptation to the downbeat nystagmus that developed during lateral gaze.

Modelling water hammer in viscoelastic pipelines: short brief

NASA Astrophysics Data System (ADS)

Urbanowicz, K.; Firkowski, M.; Zarzycki, Z.

2016-10-01

The model of water hammer in viscoelastic pipelines is analyzed. An appropriate mathematical model of water hammer in polymer pipelines is presented. An additional term has been added to continuity equation to describe the retarded deformation of the pipe wall. The mechanical behavior of viscoelastic material is described by generalized Kelvin-Voigt model. The comparison of numerical simulation and experimental data from well known papers is presented. Short discussion about obtained results are given.

A Hammer-Impact, Aluminum, Shear-Wave Seismic Source

USGS Publications Warehouse

Haines, Seth

2007-01-01

Near-surface seismic surveys often employ hammer impacts to create seismic energy. Shear-wave surveys using horizontally polarized waves require horizontal hammer impacts against a rigid object (the source) that is coupled to the ground surface. I have designed, built, and tested a source made out of aluminum and equipped with spikes to improve coupling. The source is effective in a variety of settings, and it is relatively simple and inexpensive to build.

Design of a water-powered DTH hammer for deep drilling application

NASA Astrophysics Data System (ADS)

Cho, Min Jae; Kim, Donguk; Oh, Joo Young; Yook, Se-Jin; Kim, Young Won

2017-11-01

A DTH (Down-the-hole) hammer powered by highly pressurized fluid is a drilling tool using the motion of percussion of a drill bit. In retrospect, a DTH by using compressed air as a power source has been widely used in drilling industries such as applications of mining, geothermal etc. On the other hand, another type of a DTH that uses pressurized water, called a water hammer, has recently seen deep drilling applications, while it has been rarely investigated. In this study, we designed a water-powered DTH hammer which mainly consists of several components such as a piston, a poppet valve, a cap and a bit for deep drilling applications. We optimized the components of the hammer on the basis of the results of 1D analysis using commercial software of AMESIM. An experimental study has been also conducted to investigate a performance of the designed water hammer. We measured a pressure distribution inside the hammer system as a function of time, and it thus estimates a frequency of impaction of the bit, which has been also analyzed in frequency domain. In addition, some important parameters have been discussed in conjunction with a limitation of impaction frequency as input pressure. We believe that this study provides design rules of a water-based DTH for deep drilling applications. This work is supported by KITECH of Korean government.

Rebound and jet formation of a fluid-filled sphere

NASA Astrophysics Data System (ADS)

Killian, Taylor W.; Klaus, Robert A.; Truscott, Tadd T.

2012-12-01

This study investigates the impact dynamics of hollow elastic spheres partially filled with fluid. Unlike an empty sphere, the internal fluid mitigates some of the rebound through an impulse driven exchange of energy wherein the fluid forms a jet inside the sphere. Surprisingly, this occurs on the second rebound or when the free surface is initially perturbed. Images gathered through experimentation show that the fluid reacts more quickly to the impact than the sphere, which decouples the two masses (fluid and sphere), imparts energy to the fluid, and removes rebound energy from the sphere. The experimental results are analyzed in terms of acceleration, momentum and an energy method suggesting an optimal fill volume in the neighborhood of 30%. While the characteristics of the fluid (i.e., density, viscosity, etc.) affect the fluid motion (i.e., type and size of jet formation), the rebound characteristics remain similar for a given fluid volume independent of fluid type. Implications of this work are a potential use of similar passive damping systems in sports technology and marine engineering.

Numerical investigations on the rebound phenomena and the bonding mechanisms in cold spray processes

NASA Astrophysics Data System (ADS)

Viscusi, A.

2018-05-01

Cold spray technology is a relatively new additive process allowing to create high quality metallic coatings, on both metallic and non-metallic substrates, without extensive heating of the powders sprayed. Upon impact with a target surface, conversion of kinetic energy to plastic deformation occurs, the solid particles deform and bond together. The actual bonding mechanism for cold spray particles is still not well understood, a high number of works has been carried out during the past two decades, several theories have been proposed to explain the adhesion/rebound mechanisms making the system ineffective for industrial applications. Therefore, the aim of this research activity is to better explain the complex adhesion/rebound phenomena into cold spray impact processes through numerical simulations; for this purpose, on the base of simplified hypothesis and results found in literature, an original 3D Finite Element Method (FEM) model of an aluminium particle impacting on an aluminium substrate was proposed. A cohesive behaviour algorithm was implemented in the particle-substrate contact regions aiming to simulate the bonding between the impacting particle and the substrate under specific working conditions. A rebound coefficient was also defined representing the particle residual energy. Different simulations were performed using a range of impact velocities and varying the interfacial cohesive strength. It was shown that at low impact velocities the rebound phenomenon is governed by the elastic energy stored in the system, meanwhile at high impact velocities, the rebound phenomenon is mainly due to the strain rate effects making the system mechanically stronger; therefore, a specific range of bonding velocities depending on substrate-particle contact area were found.

Measuring the rebound resilience of a bouncing ball

NASA Astrophysics Data System (ADS)

Wadhwa, Ajay

2012-09-01

Some balls which are made of high-quality rubber (an elastomeric) material, such as tennis or squash balls, could be used for the determination of an important property of such materials called resilience. Since a bouncing ball involves a single impact we call this property 'rebound resilience' and express it as the ratio of the rebound height to the initial drop height of the ball. We determine the rebound resilience for three different types of ball by calculating the coefficient of restitution of the ball-surface combination from the experimentally measurable physical quantities, such as initial drop height and time interval between successive bounces. Using these we also determine the contact time of balls with the surface of impact. For measurements we have used audio, motion and surface-temperature sensors that were interfaced through a USB port with a computer.

OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE - A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING

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

Gordon Tibbitts; Arnis Judzis

2001-04-01

This document details the progress to date on the OPTIMIZATION OF MUD HAMMER DRILLING PERFORMANCE -- A PROGRAM TO BENCHMARK THE VIABILITY OF ADVANCED MUD HAMMER DRILLING contract for the quarter starting January 2001 through March 2001. Accomplishments to date include the following: (1) On January 9th of 2001, details of the Mud Hammer Drilling Performance Testing Project were presented at a ''kick-off'' meeting held in Morgantown. (2) A preliminary test program was formulated and prepared for presentation at a meeting of the advisory board in Houston on the 8th of February. (3) The meeting was held with the advisorymore » board reviewing the test program in detail. (4) Consensus was achieved and the approved test program was initiated after thorough discussion. (5) This new program outlined the details of the drilling tests as well as scheduling the test program for the weeks of 14th and 21st of May 2001. (6) All the tasks were initiated for a completion to coincide with the test schedule. (7) By the end of March the hardware had been designed and the majority was either being fabricated or completed. (8) The rock was received and cored into cylinders.« less

Improving Non-Destructive Concrete Strength Tests Using Support Vector Machines

PubMed Central

Shih, Yi-Fan; Wang, Yu-Ren; Lin, Kuo-Liang; Chen, Chin-Wen

2015-01-01

Non-destructive testing (NDT) methods are important alternatives when destructive tests are not feasible to examine the in situ concrete properties without damaging the structure. The rebound hammer test and the ultrasonic pulse velocity test are two popular NDT methods to examine the properties of concrete. The rebound of the hammer depends on the hardness of the test specimen and ultrasonic pulse travelling speed is related to density, uniformity, and homogeneity of the specimen. Both of these two methods have been adopted to estimate the concrete compressive strength. Statistical analysis has been implemented to establish the relationship between hammer rebound values/ultrasonic pulse velocities and concrete compressive strength. However, the estimated results can be unreliable. As a result, this research proposes an Artificial Intelligence model using support vector machines (SVMs) for the estimation. Data from 95 cylinder concrete samples are collected to develop and validate the model. The results show that combined NDT methods (also known as SonReb method) yield better estimations than single NDT methods. The results also show that the SVMs model is more accurate than the statistical regression model. PMID:28793627

Effects of air vessel on water hammer in high-head pumping station

NASA Astrophysics Data System (ADS)

Wang, L.; Wang, F. J.; Zou, Z. C.; Li, X. N.; Zhang, J. C.

2013-12-01

Effects of air vessel on water hammer process in a pumping station with high-head were analyzed by using the characteristics method. The results show that the air vessel volume is the key parameter that determines the protective effect on water hammer pressure. The maximum pressure in the system declines with increasing air vessel volume. For a fixed volume of air vessel, the shape of air vessel and mounting style, such as horizontal or vertical mounting, have little effect on the water hammer. In order to obtain good protection effects, the position of air vessel should be close to the outlet of the pump. Generally, once the volume of air vessel is guaranteed, the water hammer of a entire pipeline is effectively controlled.

Rebound from marital conflict and divorce prediction.

PubMed

Gottman, J M; Levenson, R W

1999-01-01

Marital interaction has primarily been examined in the context of conflict resolution. This study investigated the predictive ability of couples to rebound from marital conflict in a subsequent positive conversation. Results showed that there was a great deal of consistency in affect across both conversations. Also examined was the ability of affective interaction to predict divorce over a 4-year period, separately in each of the two conversations. It was possible to predict divorce using affective variables from each conversation, with 82.6% accuracy from the conflict conversation and with 92.7% accuracy from the positive rebound conversation.

Body mass index kinetics around adiposity rebound in Anorexia nervosa: A case-control study.

PubMed

Neveu, Rémi; Neveu, Dorine; Carrier, Edouard; Ourrad, Nadia; Perroud, Alain; Nicolas, Alain

2016-10-01

Anorexia nervosa (AN) is associated with parameters involved in body mass index (BMI) regulation. Contrary to obesity, BMI kinetics around the adiposity rebound is not documented in AN. This study aimed at investigating which characteristics of BMI kinetics around the adiposity rebound are associated with AN. Multicentre case-control study with 101 inpatient women with AN onset after 10 years of age, and 101 healthy women, all free of overweight history and matched for age, level of education and fathers' socio-professional status. Age at adiposity rebound, pre- and post-adiposity rebound BMI velocities and accelerations (change in velocity over time) were estimated with linear mixed models using data recorded between 2 and 10 years of age. Patients had an earlier adiposity rebound (mean (standard deviation (SD)): 5.3 (1.3) vs 5.7 (1.1) years), a larger BMI at adiposity rebound (mean (SD): 15.3 [1] vs 14.9 (0.9) kg/m 2 ) and 29% lower BMI acceleration after adiposity rebound than controls. After adjustment, only BMI at adiposity rebound and BMI acceleration after adiposity rebound were associated with a higher risk of AN (Odds ratio [95% confidence interval]: 2.15 [1.41-3.46] for an increase of 1 kg/m 2 and 2.44 [1.56-4.02] for an increase of 0.1 kg/(m 2 *years 2 ) respectively). These two factors were not correlated in patients (r = 0.007, p = 0.96). A flattened evolution of BMI after adiposity rebound and higher BMI at adiposity rebound were associated with AN. Further prospective study is needed to confirm these findings. Copyright © 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

Ulnar hammer syndrome: a systematic review of the literature.

PubMed

Vartija, Larisa; Cheung, Kevin; Kaur, Manraj; Coroneos, Christopher James; Thoma, Achilleas

2013-11-01

Ulnar hammer syndrome is an uncommon form of arterial insufficiency. Many treatments have been described, and debate continues about the best option. The goal of this systematic review was to determine whether ulnar hammer syndrome has an occupational association, to identify the most reliable diagnostic test, and to determine the best treatment modality. A comprehensive literature search was conducted using the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, MEDLINE, CINAHL, and EMBASE. Data from articles meeting inclusion criteria were collected in duplicate. Methodological quality of studies was assessed using the Methodological Index for Nonrandomized Studies scale. Thirty studies were included in the systematic review. No randomized controlled trials were identified. There is low-quality evidence suggestive of an association between exposure to repetitive hand trauma and vibration and ulnar hammer syndrome. Various diagnostic investigations were used, but few were compared, making it difficult to determine the most reliable diagnostic test. Numerous nonoperative and operative treatments were reported. With nonoperative treatment, 12 percent had complete resolution and 70 percent had partial resolution of their symptoms. Of patients treated operatively, 42.5 percent had complete resolution and 42.5 percent had partial resolution of their symptoms. The heterogeneity in study design and outcome measures limits definitive conclusions about occupational association, best diagnostic test, and treatment for ulnar hammer syndrome. However, there is low-quality evidence that suggests that most patients with ulnar hammer syndrome will have partial relief of symptoms with nonoperative treatment, and operative treatment results in complete or partial resolution of symptoms in the majority of cases. Therapeutic, IV.

Improving design phase evaluations for high pile rebound sites : final report.

DOT National Transportation Integrated Search

2016-05-31

A testing program performed to help determine typical soils properties encountered during pile installation when high rebound : occurs produced a decision matrix for geotechnical engineers. High pile rebound (HPR) occurred at numerous sites in Florid...

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

PubMed Central

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

2015-01-01

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

Beyond ferryl-mediated hydroxylation: 40 years of the rebound mechanism and C–H activation

DOE PAGES

Huang, Xiongyi; Groves, John T.

2016-12-01

Since our initial report in 1976, the oxygen rebound mechanism has become the consensus mechanistic feature for an expanding variety of enzymatic C–H functionalization reactions and small molecule biomimetic catalysts. For both the biotransformations and models, an initial hydrogen atom abstraction from the substrate (R–H) by high-valent iron-oxo species (Fe n=O) generates a substrate radical and a reduced iron hydroxide, [Fe n-1–OH ·R]. This caged radical pair then evolves on a complicated energy landscape through a number of reaction pathways, such as oxygen rebound to form R–OH, rebound to a non-oxygen atom affording R–X, electron transfer of the incipient radicalmore » to yield a carbocation, R +, desaturation to form olefins, and radical cage escape. These various flavors of the rebound process, often in competition with each other, give rise to the wide range of C–H functionalization reactions performed by iron-containing oxygenases. In this review, we first recount the history of radical rebound mechanisms, their general features, and key intermediates involved. We will discuss in detail the factors that affect the behavior of the initial caged radical pair and the lifetimes of the incipient substrate radicals. Several representative examples of enzymatic C–H transformations are selected to illustrate how the behaviors of the radical pair [Fe n-1–OH ·R] determine the eventual reaction outcome. Finally, we discuss the powerful potential of “radical rebound” processes as a general paradigm for developing novel C–H functionalization reactions with synthetic, biomimetic catalysts. We envision that new chemistry will continue to arise by bridging enzymatic “radical rebound” with synthetic organic chemistry.« less

The use of titanium alloys for details of downhole hammers

NASA Astrophysics Data System (ADS)

Popelyukh, A. I.; Repin, A. A.; Alekseev, S. E.; Martyushev, N. V.; Drozdov, Yu Yu

2016-04-01

The influence of cementation technology of titanium alloy Ti-Al-Mn on its wear resistance is studied. It is established that after lubrication a friction pair with mineral oil the wear resistance of the cemented titanium alloy is comparable to wear resistance of the tempered steel 12HN3A, and in water medium surpasses it by 1.5 times. Decrease in the tendency to seizure with steel is the main reason for increase of wear resistance of titanium alloy. Industrial tests of the ASH43 hammer have shown that the use of titanium alloys for the manufacture of hammer strikers allows to increase impact capacity by 1.5 times and to increase drilling rate by 30 % compared to hammers with steel strikers.

Understanding the effect of hammering process on the vibration characteristics of cymbals

NASA Astrophysics Data System (ADS)

Kuratani, F.; Yoshida, T.; Koide, T.; Mizuta, T.; Osamura, K.

2016-09-01

Cymbals are thin domed plates used as percussion instruments. When cymbals are struck, they vibrate and radiate sound. Cymbals are made through spin forming, hammering, and lathing. The spin forming creates the basic shape of the cymbal, which determines its basic vibration characteristics. The hammering and lathing produce specific sound adjustments by changing the cymbal's vibration characteristics. In this study, we study how hammering cymbals affects their vibration characteristics. The hammering produces plastic deformation (small, shallow dents) on the cymbal's surface, generating residual stresses throughout it. These residual stresses change the vibration characteristics. We perform finite element analysis of a cymbal to obtain its stress distribution and the resulting change in vibration characteristics. To reproduce the stress distribution, we use thermal stress analysis, and then with this stress distribution we perform vibration analysis. These results show that each of the cymbal's modes has a different sensitivity to the thermal load (i.e., hammering). This difference causes changes in the frequency response and the deflection shape that significantly improves the sound radiation efficiency. In addition, we explain the changes in natural frequencies by the stress and modal strain energy distributions.

Auto-Gopher-II: an autonomous wireline rotary-hammer ultrasonic drill

NASA Astrophysics Data System (ADS)

Badescu, Mircea; Lee, Hyeong Jae; Sherrit, Stewart; Bao, Xiaoqi; Bar-Cohen, Yoseph; Jackson, Shannon; Chesin, Jacob; Zacny, Kris; Paulsen, Gale L.; Mellerowicz, Bolek; Kim, Daniel

2017-04-01

Developing technologies that would enable future NASA exploration missions to penetrate deeper into the subsurface of planetary bodies for sample collection is of great importance. Performing these tasks while using minimal mass/volume systems and with low energy consumption is another set of requirements imposed on such technologies. A deep drill, called Auto-Gopher II, is currently being developed as a joint effort between JPL's NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher II is a wireline rotary-hammer drill that combines formation breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted auger bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that has been developed as an adaptable tool for many drilling and coring applications. The USDC uses an intermediate free-flying mass to transform high frequency vibrations of a piezoelectric transducer horn tip into sonic hammering of the drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher and then integrated into a rotary hammer device to develop the Auto-Gopher-I. The lessons learned from these developments are being integrated into the development of the Auto- Gopher-II, an autonomous deep wireline drill with integrated cuttings and sample management and drive electronics. Subsystems of the wireline drill are being developed in parallel at JPL and Honeybee Robotics Ltd. This paper presents the development efforts of the piezoelectric actuator, cuttings removal and retention flutes and drive electronics.

Comparison of Piezosurgery and Hammer-Chisel in Endoscopic Dacryocystorhinostomy.

PubMed

Çukurova, Ibrahim; Bulğurcu, Suphi; Arslan, Ilker Burak; Dikilitaş, Bünyamin

2018-05-08

In this study, we compared the advantages and disadvantages of piezosurgery and hammer-chisel used in endoscopic dacryocystorhinostomy (EDCR). Between January 2012 and January 2016, 10 women and 8 men in whom piezosurgery was used (group 1) and 11 women and 7 men in whom hammer-chisel was used (group 2) during EDCR operations were compared retrospectively. Recurrence, operation time, postoperative bleeding, and operative cost were evaluated in patients who were followed for an average of 11.8 months. In addition, visual analogue scale (VAS) was used to assess pain at 6 hours postoperatively. No recurrence was observed in group 1, but recurrence was observed in 2 patients in group 2 (P = 0.685). There was no postoperative bleeding in both groups. The mean duration of operation was 30.6 ± 8.2 minutes in group 1 and 46.8 ± 9.5 minutes in group 2 (P = 0.038). The VAS score in group 1 was 2.7 ± 1.4 and the VAS score in group 2 was 5.8 ± 2.2 (P = 0.01). Piezosurgery costs an additional $325 for each patient while the use of the hammer-chisel does not incur additional costs. Piezosurgery causes shorter operation time, less recurrence, and less pain when compared with hammer-chisel.

When Does Tool Use Become Distinctively Human? Hammering in Young Children

ERIC Educational Resources Information Center

Kahrs, Björn Alexander; Jung, Wendy P.; Lockman, Jeffrey J.

2014-01-01

This study examines the development of hammering within an ontogenetic and evolutionary framework using motion-capture technology. Twenty-four right-handed toddlers (19-35 months) wore reflective markers while hammering a peg into a peg-board. The study focuses on the motor characteristics that make tool use uniquely human: wrist involvement,…

Postglacial rebound and fault instability in Fennoscandia

NASA Astrophysics Data System (ADS)

Wu, Patrick; Johnston, Paul; Lambeck, Kurt

1999-12-01

The best available rebound model is used to investigate the role that postglacial rebound plays in triggering seismicity in Fennoscandia. The salient features of the model include tectonic stress due to spreading at the North Atlantic Ridge, overburden pressure, gravitationally self-consistent ocean loading, and the realistic deglaciation history and compressible earth model which best fits the sea-level and ice data in Fennoscandia. The model predicts the spatio-temporal evolution of the state of stress, the magnitude of fault instability, the timing of the onset of this instability, and the mode of failure of lateglacial and postglacial seismicity. The consistency of the predictions with the observations suggests that postglacial rebound is probably the cause of the large postglacial thrust faults observed in Fennoscandia. The model also predicts a uniform stress field and instability in central Fennoscandia for the present, with thrust faulting as the predicted mode of failure. However, the lack of spatial correlation of the present seismicity with the region of uplift, and the existence of strike-slip and normal modes of current seismicity are inconsistent with this model. Further unmodelled factors such as the presence of high-angle faults in the central region of uplift along the Baltic coast would be required in order to explain the pattern of seismicity today in terms of postglacial rebound stress. The sensitivity of the model predictions to the effects of compressibility, tectonic stress, viscosity and ice model is also investigated. For sites outside the ice margin, it is found that the mode of failure is sensitive to the presence of tectonic stress and that the onset timing is also dependent on compressibility. For sites within the ice margin, the effect of Earth rheology is shown to be small. However, ice load history is shown to have larger effects on the onset time of earthquakes and the magnitude of fault instability.

STUDY ON OPERATING CHARACTERISTECS OF WATER HAMMER GENERATING DEVICE FOR TREATMENT OF MICROORGANISM

NASA Astrophysics Data System (ADS)

Hamada, Tatsuhisa; Endo, Shigekatsu; Oda, Akira; Shimizu, Yasushi

The phenomenon that has been actualized due to the water quality deterioration because of the inflow of drainage and the industrial wastewater includes the phenomenon that is called water-bloom generated in the freshwater environment made a eutrophic. This is becoming a serious problem to secure the water.Mixing with the drinking water has already been confirmed, and the generation of water-bloom is becoming a big social problem, and fundamental measures have not been established yet.On the other hand, authors are proving the pressure to be a fast the pressure speed of the impact pressure by the water hammer and effective in the destruction of the blue-green algae.In this studies, the hydraulics flow characteristics of an effective water hammer pressure generator to the shredding of the water-bloom cell were examined.As a result, there was a boundary in the region where the water hammer was generated by length and the water supply head of conduit, and the water hammer pressure was able to be understood to be influenced according to the angle of the valve that generated the water hammer in addition in the water hammer generator.The demonstration in the locale was confirmed based on these and the scale etc. of an effective device to the doing water-bloom processing were able to be confirmed by continuous running.

9. VIEW OF 'BLUE STREAK' HAMMER MILL (Prater Pulverizer Co., ...

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

9. VIEW OF 'BLUE STREAK' HAMMER MILL (Prater Pulverizer Co., Chicago, Illinois), LOCATED IN THE SOUTHEAST CORNER OF THE BASEMENT, WAS ADDED IN THE EARLY 1930s. THIS WAS THE MILL'S FIRST ELECTRIC-POWERED MACHINERY. THE HAMMER MILL WAS USED TO PULVERIZE OATS, ALFALFA MEAL, AND CORN. Photographer: Louise Taft Cawood, July 1986 - Alexander's Grist Mill, Lock 37 on Ohio & Erie Canal, South of Cleveland, Valley View, Cuyahoga County, OH

Ultrasonic/Sonic Rotary-Hammer Drills

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi; Kassab, Steve

2010-01-01

Ultrasonic/sonic rotary-hammer drill (USRoHD) is a recent addition to the collection of apparatuses based on ultrasonic/sonic drill corer (USDC). As described below, the USRoHD has several features, not present in a basic USDC, that increase efficiency and provide some redundancy against partial failure. USDCs and related apparatuses were conceived for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. They have been described in numerous previous NASA Tech Briefs articles. To recapitulate: A USDC can be characterized as a lightweight, lowpower, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. A basic USDC includes a piezoelectric stack, an ultrasonic transducer horn connected to the stack, a free mass ( free in the sense that it can bounce axially a short distance between hard stops on the horn and the bit), and a tool bit. The piezoelectric stack creates ultrasonic vibrations that are mechanically amplified by the horn. The bouncing of the free mass between the hard stops generates the sonic vibrations. The combination of ultrasonic and sonic vibrations gives rise to a hammering action (and a resulting chiseling action at the tip of the tool bit) that is more effective for drilling than is the microhammering action of ultrasonic vibrations alone. The hammering and chiseling actions are so effective that unlike in conventional twist drilling, little applied axial force is needed to make the apparatus advance into the material of interest. There are numerous potential applications for USDCs and related apparatuses in geological exploration on Earth and on remote planets. In early USDC experiments, it was observed that accumulation of cuttings in a drilled hole causes the rate of penetration of the USDC to decrease steeply with depth, and that the rate of penetration can be increased by removing the cuttings. The USRoHD concept provides for

Optimal Control of the Valve Based on Traveling Wave Method in the Water Hammer Process

NASA Astrophysics Data System (ADS)

Cao, H. Z.; Wang, F.; Feng, J. L.; Tan, H. P.

2011-09-01

Valve regulation is an effective method for process control during the water hammer. The principle of d'Alembert traveling wave theory was used in this paper to construct the exact analytical solution of the water hammer, and the optimal speed law of the valve that can reduce the water hammer pressure in the maximum extent was obtained. Combining this law with the valve characteristic curve, the principle corresponding to the valve opening changing with time was obtained, which can be used to guide the process of valve closing and to reduce the water hammer pressure in the maximum extent.

Characterisation of rebound depolarisation in mice deep dorsal horn neurons in vitro.

PubMed

Rivera-Arconada, Ivan; Lopez-Garcia, Jose A

2015-09-01

Spinal dorsal horn neurons constitute the first relay for pain processing and participate in the processing of other sensory, motor and autonomic information. At the cellular level, intrinsic excitability is a factor contributing to network function. In turn, excitability is set by the array of ionic conductance expressed by neurons. Here, we set out to characterise rebound depolarisation following hyperpolarisation, a feature frequently described in dorsal horn neurons but never addressed in depth. To this end, an in vitro preparation of the spinal cord from mice pups was used combined with whole-cell recordings in current and voltage clamp modes. Results show the expression of H- and/or T-type currents in a significant proportion of dorsal horn neurons. The expression of these currents determines the presence of rebound behaviour at the end of hyperpolarising pulses. T-type calcium currents were associated to high-amplitude rebounds usually involving high-frequency action potential firing. H-currents were associated to low-amplitude rebounds less prone to elicit firing or firing at lower frequencies. For a large proportion of neurons expressing both currents, the H-current constitutes a mechanism to ensure a faster response after hyperpolarisations, adjusting the latency of the rebound firing. We conclude that rebound depolarisation and firing are intrinsic factors to many dorsal horn neurons that may constitute a mechanism to integrate somatosensory information in the spinal cord, allowing for a rapid switch from inhibited-to-excited states.

Schmidt-hammer exposure-age dating (SHD) of Lateglacial rock glacier systems near the eastern margin of the European Alps

NASA Astrophysics Data System (ADS)

Kellerer-Pirklbauer, Andreas

2016-04-01

Rock glaciers are widespread permafrost landforms in Austria. Various rock glacier inventories list more than 4500 rock glaciers in the country; some 30-40% of them are intact. Relict (permafrost free) and pseudo-relict rock glaciers (sporadic and isolated permafrost particularly near the root zone) prevail in number. Rock glaciers are commonly formed over a period of several ka. Dating such landforms helps to understand palaeoclimatic conditions. In this study three rock glaciers consisting of gneiss were dated applying the Schmidt-hammer exposure-age dating (SHD) method. The rock glaciers are located at three neighbouring cirques in the Seckauer Tauern Range named Reichart Rock Glacier (RRG, area 1.26 km², length 1800 m, elevation range 1520-1940 m a.s.l.), Schöneben Rock Glacier (SRG, 0.11 km², 750 m, 1715-1905 m a.s.l.), and Dürrtal Rock Glacier (DRG, 0.08 km², 850 m, 1750-1980 m a.s.l.). RRG is one of the largest rock glaciers in Austria. All three landforms are influenced by lenses of permafrost at present (as indicated by ERT). During the LGM the Seckauer Tauern were covered by valley glaciers and deglaciation occurred presumably already early in the Alpine Lateglacial period. An analogue N-type Schmidt-hammer (proceq) was used for measuring the surface strength of stable blocks at the rock glacier surface by recording a rebound value (R-value) of a spring-loaded bolt. The R-value gives a relative measure of the surface hardness and hence time since exposure to weathering. Eight (RRG) or six (SRG, DRG) Schmidt-hammer measurement sites (with 50-100 individual readings) aligned along longitudinal transects (=former central flow line) between a talus slope (with relatively fresh boulders) in the root zone and the frontal ridge were measured. Mean R-value differences of 30.5 at RRG, 25.1 at SRG, and 20.7 at DRG were revealed along the three transects. The differences between the lowest and the highest R-value at the rock glaciers itself were 19.0 at RRG, 15

Automatic hammering of nano-patterns on special polymer film by using a vibrating AFM tip

PubMed Central

2012-01-01

Complicated nano-patterns with linewidth less than 18 nm can be automatically hammered by using atomic force microscopy (AFM) tip in tapping mode with high speed. In this study, the special sample was thin poly(styrene-ethylene/butylenes-styrene) (SEBS) block copolymer film with hexagonal spherical microstructures. An ordinary silicon tip was used as a nano-hammer, and the entire hammering process is controlled by a computer program. Experimental results demonstrate that such structure-tailored thin films enable AFM tip hammering to be performed on their surfaces. Both imprinted and embossed nano-patterns can be generated by using a vibrating tip with a larger tapping load and by using a predefined program to control the route of tip movement as it passes over the sample’s surface. Specific details for the fabrication of structure-tailored SEBS film and the theory for auto-hammering patterns were presented in detail. PMID:22889045

Rebound nystagmus: EOG analysis of a case with a floccular tumour.

PubMed Central

Yamazaki, A; Zee, D S

1979-01-01

Eye movements were recorded and quantitatively analysed in a patient with a tumour initially involving the cerebellar flocculus. Ocular motor abnormalities included (1) impaired smooth pursuit, (2) impaired cancellation of the vestibulo-ocular reflex when fixating an object rotating with the head, and (3) gaze paretic and rebound nystagmus. Comparable findings have been reported in monkeys with experimental floccular lesions. The rebound nystagmus (but not the other ocular motor abnormalities) disappeared when the tumour appeared to invade the brain stem in the region near the vestibular nuclei. This finding suggests that the floccular lesion unmasked a bias which created rebound nystagmus and that the bias probably arose in the vestibular nuclei. PMID:508695

Rebound effect of modern drugs: serious adverse event unknown by health professionals.

PubMed

Teixeira, Marcus Zulian

2013-01-01

Supported in the Hippocratic aphorism primum non nocere, the bioethical principle of non-maleficence pray that the medical act cause the least damage or injury to the health of the patient, leaving it to the doctor to assess the risks of a particular therapy through knowledge of possible adverse events of drugs. Among these, the rebound effect represents a common side effect to numerous classes of modern drugs, may cause serious and fatal disorders in patients. This review aims to clarify the health professionals on clinical and epidemiological aspects of rebound phenomenon. A qualitative, exploratory and bibliographic review was held in the PubMed database using the keywords 'rebound', 'withdrawal', 'paradoxical', 'acetylsalicylic acid', 'anti-inflammatory', 'bronchodilator', 'antidepressant', 'statin', 'proton pump inhibitor' and 'bisphosphonate'. The rebound effect occurs after discontinuation of numerous classes of drugs that act contrary to the disease disorders, exacerbating them at levels above those prior to treatment. Regardless of the disease, the drug and duration of treatment, the phenomenon manifests itself in a small proportion of susceptible individuals. However, it may cause serious and fatal adverse events should be considered a public health problem in view of the enormous consumption of drugs by population. Bringing together a growing and unquestionable body of evidence, the physician needs to have knowledge of the consequences of the rebound effect and how to minimize it, increasing safety in the management of modern drugs. On the other hand, this rebound can be used in a curative way, broadening the spectrum of the modern therapeutics. Copyright © 2012 Elsevier Editora Ltda. All rights reserved.

Effects of Exercise Rehab on Male Asthmatic Patients: Aerobic Verses Rebound Training

PubMed Central

Zolaktaf, Vahid; Ghasemi, Gholam A; Sadeghi, Morteza

2013-01-01

Background: There are some auspicious records on applying aerobic exercise for asthmatic patients. Recently, it is suggested that rebound exercise might even increase the gains. This study was designed to compare the effects of rebound therapy to aerobic training in male asthmatic patients. Methods: Sample included 37 male asthmatic patients (20-40 years) from the same respiratory clinic. After signing the informed consent, subjects volunteered to take part in control, rebound, or aerobic groups. There was no change in the routine medical treatment of patients. Supervised exercise programs continued for 8 weeks, consisting of two sessions of 45 to 60 minutes per week. Criteria measures were assessed pre- and post exercise program. Peak exercise capacity (VO2peak) was estimated by modified Bruce protocol, Forced vital capacity (FVC), Forced expiratory volume in 1 second (FEV1), and FEV1% were measured by spirometer. Data were analyzed by repeated measure analysis of variance (ANOVA). Results: Significant interactions were observed for all 4 criteria measures (P < 0.01), meaning that both the exercise programs were effective in improving FVC, FEV1, FEV1%, and VO2peak. Rebound exercise produced more improvement in FEV1, FEV1%, and VO2peak. Conclusions: Regular exercise strengthens the respiratory muscles and improves the cellular respiration. At the same time, it improves the muscular, respiratory, and cardio-vascular systems. Effects of rebound exercise seem to be promising. Findings suggest that rebound exercise is a useful complementary means for asthmatic male patients. PMID:23717762

Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill

NASA Technical Reports Server (NTRS)

Sherrit, Stewart; Domm, Lukas; Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Badescu, Mircea

2012-01-01

The search for present or past life in the Universe is one of the most important objectives of NASA's exploration missions. Drills for subsurface sampling of rocks, ice and permafrost are an essential tool for astrobiology studies on other planets. Increasingly, it is recognized that drilling via a combination of rotation and hammering offers an efficient and effective rapid penetration mechanism. The rotation provides an intrinsic method for removal of cuttings from the borehole while the impact and shear forces aids in the fracturing of the penetrated medium. Conventional drills that use a single actuator are based on a complex mechanism with many parts and their use in future mission involves greater risk of failure and/or may require lubrication that can introduce contamination. In this paper, a compact drill is reported that uses a single piezoelectric actuator to produce hammering and rotation of the bit. A horn with asymmetric grooves was design to impart a longitudinal (hammering) and transverse force (rotation) to a keyed free mass. The drill requires low axial pre-load since the hammering-impacts fracture the rock under the bit kerf and rotate the bit to remove the powdered cuttings while augmenting the rock fracture via shear forces. The vibrations 'fluidize' the powdered cuttings inside the flutes reducing the friction with the auger surface. This action reduces the consumed power and heating of the drilled medium helping to preserve the pristine content of the acquired samples. The drill consists of an actuator that simultaneously impacts and rotates the bit by applying force and torque via a single piezoelectric stack actuator without the need for a gearbox or lever mechanism. This can reduce the development/fabrication cost and complexity. In this paper, the drill mechanism will be described and the test results will be reported and discussed.

Rebound Syndrome in Patients With Multiple Sclerosis After Cessation of Fingolimod Treatment.

PubMed

Hatcher, Stacy Ellen; Waubant, Emmanuelle; Nourbakhsh, Bardia; Crabtree-Hartman, Elizabeth; Graves, Jennifer S

2016-07-01

The appropriate sequencing of agents with strong immune system effects has become increasingly important. Transitions require careful balance between safety and protection against relapse. The cases presented herein highlight that rebound events after ceasing fingolimod treatment may happen even with short washout periods (4 weeks) and may perpetuate despite steroid treatment or the immediate use of fast-acting immune therapies, such as rituximab. To describe rebound syndrome in patients with multiple sclerosis (MS) after cessation of fingolimod treatment. Clinical and demographic data were extracted from electronic medical records from the University of California, San Francisco, Multiple Sclerosis Center from January 2014 to December 2015. Magnetic resonance images were reviewed by MS neurologists (J.S.G., E.W., B.N., and E.C.H.). Rebound syndrome was defined as new severe neurological symptoms after ceasing fingolimod treatment, with the development of multiple new or enhancing lesions exceeding baseline activity. We reviewed the PubMed database from January 2010 to December 2015 for similar cases of severe disease reactivation after ceasing fingolimod treatment using search terms fingolimod and either rebound or reactivation. Participants were included if they stopped receiving fingolimod between January 2014 and December 2015. Five patients were identified who experienced rebound after ceasing fingolimod treatment. Each patient received treatment with oral fingolimod for various durations. Occurrence of rebound after ceasing fingolimod treatment. The mean (SD) age of the 5 female patients presented in this case series was 35.2 (6.4) years. Of the 46 patients that stopped fingolimod treatment within the 2-year period, 5 (10.9%) experienced severe relapse 4 to 16 weeks after ceasing fingolimod treatment. Despite varying prior severity of relapsing-remitting course, all participants experienced unexpectedly severe clinical relapses accompanied by drastic

The utility of inpatient rebound bilirubin levels in infants readmitted after birth hospitalization for hyperbilirubinemia.

PubMed

Berkwitt, Adam; Osborn, Rachel; Grossman, Matthew

2015-02-01

There are few data evaluating the role of inpatient rebound bilirubin levels in the management of infants readmitted after their birth hospitalization for indirect hyperbilirubinemia. The goal of the present study was to evaluate the clinical utility of inpatient rebound bilirubin levels within this patient population. A retrospective cohort study was conducted of 226 infants readmitted after their birth hospitalization for indirect hyperbilirubinemia. Data from 130 infants with rebound bilirubin levels drawn at a mean of 6.1±2.4 hours after discontinuation of phototherapy were compared with data from 96 infants without rebound bilirubin levels. The primary outcome was readmission to the hospital, and secondary outcomes included length of stay and discharge time. A subgroup analysis compared characteristics of children who required repeat phototherapy versus those who did not. Overall, 5 of 130 patients from the rebound group were readmitted compared with 4 of 96 patients from the no-rebound group (P=.98). Length of stay was significantly longer for patients with rebound bilirubin levels (27.7 vs 23.2 hours; P=.001). Patients with bilirubin levels lowered to ≤14 mg/dL were less likely to receive repeat phototherapy than those with levels>14 mg/dL (2 of 129 vs 12 of 97; P=.001). Early inpatient rebound bilirubin levels do not successfully predict which patients will require hospital readmission for repeat phototherapy. Children with bilirubin levels lowered to ≤14 mg/dL with phototherapy are unlikely to receive repeat phototherapy. Copyright © 2015 by the American Academy of Pediatrics.

Observations of the collapses and rebounds of millimeter-sized lithotripsy bubbles

PubMed Central

Kreider, Wayne; Crum, Lawrence A.; Bailey, Michael R.; Sapozhnikov, Oleg A.

2011-01-01

Bubbles excited by lithotripter shock waves undergo a prolonged growth followed by an inertial collapse and rebounds. In addition to the relevance for clinical lithotripsy treatments, such bubbles can be used to study the mechanics of inertial collapses. In particular, both phase change and diffusion among vapor and noncondensable gas molecules inside the bubble are known to alter the collapse dynamics of individual bubbles. Accordingly, the role of heat and mass transport during inertial collapses is explored by experimentally observing the collapses and rebounds of lithotripsy bubbles for water temperatures ranging from 20 to 60 °C and dissolved gas concentrations from 10 to 85% of saturation. Bubble responses were characterized through high-speed photography and acoustic measurements that identified the timing of individual bubble collapses. Maximum bubble diameters before and after collapse were estimated and the corresponding ratio of volumes was used to estimate the fraction of energy retained by the bubble through collapse. The rebounds demonstrated statistically significant dependencies on both dissolved gas concentration and temperature. In many observations, liquid jets indicating asymmetric bubble collapses were visible. Bubble rebounds were sensitive to these asymmetries primarily for water conditions corresponding to the most dissipative collapses. PMID:22088027

Rebound Effects in the Context of Developing Country Efficiency

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

de la Rue du Can, Stephane; McNeil, Michael A.; Leventis, Greg

Energy efficiency-related “rebound effects” usually refer to the tendency of most consumers to increase their use of energy services in response to efficiency measures that have reduced their energy costs. This phenomenon is one reason why energy efficiency policies often result in lower energy savings than engineering-based estimates predict. Rebound effects have been the subject of intense debate in the field of energy efficiency policy for many years.1 In the past, the focus of this debate has been on the perceived loss of the expected energy savings and related benefits resulting from the rebound effects. However, more recently, there hasmore » been a growing recognition that policymakers need to consider the health, economic and other non-energy benefits that often result from the increase in energy services represented by user “rebound effects”. This is especially true in developing countries where basic energy service demands—such as lighting, heating, cooling, and refrigeration of food—are often not being met. As economic conditions improve and household incomes increase, demand for increased energy services (such as space conditioning and appliances) tends to rise rapidly. Improving energy efficiency reduces the amount of energy needed to produce one unit of energy service output (for example an hour of cooling at 21°C delivered for X vs Y kWh). Greater efficiency therefore often enables more rapid increased in energy services (and sometimes access), expanding the amount of services that can be provided by a fixed amount (or cost) of energy.« less

Peer Review of March 2013 LDV Rebound Report By Small ...

EPA Pesticide Factsheets

The regulatory option of encouraging the adoption of advanced technologies for improving vehicle efficiency can result in significant fuel savings and GHG emissions benefits. At the same time, it is possible that some of these benefits might be offset by additional driving that is encouraged by the reduced costs of operating more efficient vehicles. This so called “rebound effect”, the increased driving that results from an improvement in the energy efficiency of a vehicle, must be determined in order to reliably estimate the overall benefits of GHG regulations for light-duty vehicles. Dr. Ken Small, an Economist at the Department of Economics, University of California at Irvine, with contributions by Dr. Kent Hymel, Department of Economics, California State University at Northridge, have developed a methodology to estimate the rebound effect for light-duty vehicles in the U.S. Specifically, rebound is estimated as the change in vehicle miles traveled (VMT) with respect to the change in per mile fuel costs that can occur, for example, when vehicle operating efficiency is improved. The model analyzes aggregate personal motor-vehicle travel within a simultaneous model of aggregate VMT, fleet size, fuel efficiency, and congestion formation. To use the peer review process to help assure that the methodologies considered by the U.S. EPA for estimating VMT rebound have been thoroughly examined.

Biological therapies (immunomodulatory drugs), worsening of psoriasis and rebound effect: new evidence of similitude.

PubMed

Teixeira, Marcus Zulian

2016-11-01

Employing the secondary action or adaptative reaction of the organism as therapeutic response, homeopathy uses the treatment by similitude (similia similibus curentur) administering to sick individuals the medicines that caused similar symptoms in healthy individuals. Such homeostatic or paradoxical reaction of the organism is scientifically explained through the rebound effect of drugs, which cause worsening of symptoms after withdrawal of several palliative treatments. Despite promoting an improvement in psoriasis at the beginning of the treatment, modern biological therapies provoke worsening of the psoriasis (rebound psoriasis) after discontinuation of drugs. Exploratory qualitative review of the literature on the occurrence of the rebound effect with the use of immunomodulatory drugs [T-cell modulating agents and tumor necrosis factor (TNF) inhibitors drugs] in the treatment of psoriasis. Several researches indicate the rebound effect as the mechanism of worsening of psoriasis with the use of efalizumab causing the suspension of its marketing authorization in 2009, in view of some severe cases. Other studies also have demonstrated the occurrence of rebound psoriasis with the use of alefacept, etanercept and infliximab. As well as studied in other classes of drugs, the rebound effect of biologic agents supports the principle of similitude (primary action of the drugs followed by secondary action and opposite of the organism). Copyright © 2016 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Warfarin Poisoning with Delayed Rebound Toxicity.

PubMed

Berling, Ingrid; Mostafa, Ahmed; Grice, Jeffrey E; Roberts, Michael S; Isbister, Geoffrey K

2017-02-01

Intentional poisoning with warfarin is not the same as over-anticoagulation, for which guidelines exist. The coagulopathy resulting from a warfarin overdose is reversed with vitamin K 1 , the dose and timing of which is often guided by experience with the management of over-anticoagulation with warfarin therapy, rather than acute overdose. We report a case of a 50-year-old man who ingested an unknown amount of his warfarin, venlafaxine, and paracetamol. He presented with an international normalized ratio (INR) of 2.5, which steadily increased over 24 h to 7, despite receiving an initial 1 mg of vitamin K 1 . He was then treated with 5 mg vitamin K 1 , and once the INR returned to 4.5, 40 h post ingestion, he was discharged home. He was also treated with a full course of acetylcysteine for the paracetamol overdose. The following day his INR rebounded to 8.5 and he suffered a spontaneous epistaxis requiring readmission; he was treated with low titrated doses of vitamin K 1 . The warfarin concentration was 74.6 μg/mL 26 h post ingestion and decreased to 3.7 μg/mL over 72 h. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Our case highlights the risk of a rebound elevated INR even 3 days after acute warfarin overdose despite treatment with vitamin K 1 . Understanding the pharmacokinetics of vitamin K 1 in comparison with warfarin, repeat INR testing, and continued treatment with oral vitamin K 1 may help avoid complications of rebound coagulopathy in warfarin overdose. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Muffling Hammer Blows In A Workshop

NASA Technical Reports Server (NTRS)

Thiele, Alfred W.; Gilbert, Jeffrey L.; Gutow, David A.

1994-01-01

Sound-deadening bags placed on hammered workpieces. Useful in many workshop situations. Fabricated easily and inexpensively. Bags filled with particles of sand, metal shot, plastic, or glass, then sewn or molded shut. Tailored to fit special configurations of some workpieces. Devices used to deaden print rollers and to reduce vibrations in main-injector inlet manifold of rocket engine.

Astronaut David Scott watching hammer and feather fall to lunar surface

NASA Technical Reports Server (NTRS)

1971-01-01

Astronaut David R. Scott, Apollo 15 commander, watches a geological hammer and a feather hit the lunar surface simultaneously in a test of Galileo's law of motion concerning falling bodies, as seen in this color reproduction taken from a transmission made by the RCA color television camera mounted on the Lunar Roving Vehicle. Scott released the hammer from his right hand and the feather from his left at the same instant. This experiment occured toward the end of the third and final lunar surface extravehicular activity.

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

Analysis on shock wave speed of water hammer of lifting pipes for deep-sea mining

NASA Astrophysics Data System (ADS)

Zhou, Zhi-jin; Yang, Ning; Wang, Zhao

2013-04-01

Water hammer occurs whenever the fluid velocity in vertical lifting pipe systems for deep-sea mining suddenly changes. In this work, the shock wave was proven to play an important role in changing pressures and periods, and mathematical and numerical modeling technology was presented for simulated transient pressure in the abnormal pump operation. As volume concentrations were taken into account of shock wave speed, the experiment results about the pressure-time history, discharge-time history and period for the lifting pipe system showed that: as its concentrations rose up, the maximum transient pressure went down, so did its discharges; when its volume concentrations increased gradually, the period numbers of pressure decay were getting less and less, and the corresponding shock wave speed decreased. These results have highly coincided with simulation results. The conclusions are important to design lifting transporting system to prevent water hammer in order to avoid potentially devastating consequences, such as damage to components and equipment and risks to personnel.

A mathematical analysis of rebound in a target-mediated drug disposition model: II. With feedback.

PubMed

Aston, Philip J; Derks, Gianne; Agoram, Balaji M; van der Graaf, Piet H

2017-07-01

We consider the possibility of free receptor (antigen/cytokine) levels rebounding to higher than the baseline level after the application of an antibody drug using a target-mediated drug disposition model. It is assumed that the receptor synthesis rate experiences homeostatic feedback from the receptor levels. It is shown for a very fast feedback response, that the occurrence of rebound is determined by the ratio of the elimination rates, in a very similar way as for no feedback. However, for a slow feedback response, there will always be rebound. This result is illustrated with an example involving the drug efalizumab for patients with psoriasis. It is shown that slow feedback can be a plausible explanation for the observed rebound in this example.

Solenoid hammer valve developed for quick-opening requirements

NASA Technical Reports Server (NTRS)

Wrench, E. H.

1967-01-01

Quick-opening lightweight solenoid hammer valve requires a low amount of electrical energy to open, and closes by the restoring action of the mechanical springs. This design should be applicable to many quick-opening requirements in fluid systems.

Development and validation of a method to directly measure the cable force during the hammer throw.

PubMed

Brice, Sara M; Ness, Kevin F; Rosemond, Doug; Lyons, Keith; Davis, Mark

2008-05-01

The development of cable force during hammer-throw turns is crucial to the throw distance. In this paper, we present a method that is capable of measuring cable force in real time and, as it does not interfere with technique, it is capable of providing immediate feedback to coaches and athletes during training. A strain gauge was mounted on the wires of three hammers to measure the tension in the wire and an elite male hammer thrower executed three throws with each hammer. The output from the gauges was recorded by a data logger positioned on the lower back of the thrower. The throws were captured by three high-speed video cameras and the three-dimensional position of the hammer's head was determined by digitizing the images manually. The five best throws were analysed. The force acting on the hammer's head was calculated from Newton's second law of motion and this was compared with the force measured via the strain gauge. Qualitatively the time dependence of the two forces was essentially the same, although the measured force showed more detail in the troughs of the force-time curves. Quantitatively the average difference between the measured and calculated forces over the five throws was 76 N, which corresponds to a difference of 3.8% for a cable force of 2000 N.

Identification of characteristic frequencies of damaged railway tracks using field hammer test measurements

NASA Astrophysics Data System (ADS)

Oregui, M.; Li, Z.; Dollevoet, R.

2015-03-01

In this paper, the feasibility of the Frequency Response Function (FRF)-based statistical method to identify the characteristic frequencies of railway track defects is studied. The method compares a damaged track state to a healthy state based on non-destructive field hammer test measurements. First, a study is carried out to investigate the repeatability of hammer tests in railway tracks. By changing the excitation and measurement locations it is shown that the variability introduced by the test process is negligible. Second, following the concepts of control charts employed in process monitoring, a method to define an approximate healthy state is introduced by using hammer test measurements at locations without visual damage. Then, the feasibility study includes an investigation into squats (i.e. a major type of rail surface defect) of varying severity. The identified frequency ranges related to squats agree with those found in an extensively validated vehicle-borne detection system. Therefore, the FRF-based statistical method in combination with the non-destructive hammer test measurements has the potential to be employed to identify the characteristic frequencies of damaged conditions in railway tracks in the frequency range of 300-3000 Hz.

Brain prolactin is involved in stress-induced REM sleep rebound.

PubMed

Machado, Ricardo Borges; Rocha, Murilo Ramos; Suchecki, Deborah

2017-03-01

REM sleep rebound is a common behavioural response to some stressors and represents an adaptive coping strategy. Animals submitted to multiple, intermittent, footshock stress (FS) sessions during 96h of REM sleep deprivation (REMSD) display increased REM sleep rebound (when compared to the only REMSD ones, without FS), which is correlated to high plasma prolactin levels. To investigate whether brain prolactin plays a role in stress-induced REM sleep rebound two experiments were carried out. In experiment 1, rats were either not sleep-deprived (NSD) or submitted to 96h of REMSD associated or not to FS and brains were evaluated for PRL immunoreactivity (PRL-ir) and determination of PRL concentrations in the lateral hypothalamus and dorsal raphe nucleus. In experiment 2, rats were implanted with cannulas in the dorsal raphe nucleus for prolactin infusion and were sleep-recorded. REMSD associated with FS increased PRL-ir and content in the lateral hypothalamus and all manipulations increased prolactin content in the dorsal raphe nucleus compared to the NSD group. Prolactin infusion in the dorsal raphe nucleus increased the time and length of REM sleep episodes 3h after the infusion until the end of the light phase of the day cycle. Based on these results we concluded that brain prolactin is a major mediator of stress-induced REMS. The effect of PRL infusion in the dorsal raphe nucleus is discussed in light of the existence of a bidirectional relationship between this hormone and serotonin as regulators of stress-induced REM sleep rebound. Copyright © 2016 Elsevier Inc. All rights reserved.

Water hammer prediction and control: the Green's function method

NASA Astrophysics Data System (ADS)

Xuan, Li-Jun; Mao, Feng; Wu, Jie-Zhi

2012-04-01

By Green's function method we show that the water hammer (WH) can be analytically predicted for both laminar and turbulent flows (for the latter, with an eddy viscosity depending solely on the space coordinates), and thus its hazardous effect can be rationally controlled and minimized. To this end, we generalize a laminar water hammer equation of Wang et al. (J. Hydrodynamics, B2, 51, 1995) to include arbitrary initial condition and variable viscosity, and obtain its solution by Green's function method. The predicted characteristic WH behaviors by the solutions are in excellent agreement with both direct numerical simulation of the original governing equations and, by adjusting the eddy viscosity coefficient, experimentally measured turbulent flow data. Optimal WH control principle is thereby constructed and demonstrated.

36. SOUTHWEST TO BELTPOWERED CIRCA 1900 DROP HAMMER IN NORTHEASTERN ...

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

36. SOUTHWEST TO BELT-POWERED CIRCA 1900 DROP HAMMER IN NORTHEASTERN QUADRANT OF FACTORY OPPOSITE FROM THE BLACKSMITH SHOP AREA. THIS MACHINE WAS USED TO SHAPE THE STEEL VANE HINGE PART AFTER IT WAS HEATED IN THE FORGE IN THE ADJACENT BLACKSMITH SHOP AREA. USE OF THE ROTATING POWER OF THE PULLEY AT THE TO MADE LIFTING THE HAMMER COMPARATIVELY QUICK AND EASY. AROUND THE MACHINE ARE WHEEL PARTS FOR ELI WINDMILLS. AT THE LEFT FOREGROUND IS A CIRCA 1900 FOUR-SPINDLE PRODUCTION DRILL PRESS WHICH WAS RELOCATED TO THIS AREA APPARENTLY AFTER THE END OF WINDMILL MANUFACTURE. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

At a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, KSC and 45th Space Wing employees share the honors as recipients of the Hammer Award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. Morley Winograd, director of the National Partnership for Reinventing Government, presented the award to Ed Gormel and Chris Fairey, co-chairs of the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the J-BOSC SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base.

Consecutive rebounds in plasma viral load are associated with virological failure at 52 weeks among HIV-infected patients.

PubMed

Raboud, Janet M; Rae, Sandra; Woods, Ryan; Harris, Marianne; Montaner, Julio S G

2002-08-16

To describe the characteristics and predictors of transient plasma viral load (pVL) rebounds among patients on stable antiretroviral therapy and to determine the effect of one or more pVL rebounds on virological response at week 52. Individual data were combined from 358 patients from the INCAS, AVANTI-2 and AVANTI-3 studies. Logistic regression models were used to determine the relationship between the magnitude of an increase in pVL and the probability of returning to the lower limit of quantification (LLOQ: 20-50 copies/ml) and to determine the odds of virological success at 52 weeks associated with single and consecutive pVL rebounds. A group of 165 patients achieved a pVL nadir < LLOQ; of these, 85 patients experienced pVL rebounds within 52 weeks. The probability of a pVL rebound was greater among patients who did not adhere to treatment (68% vs 49%; P < 0.05). The probability of reachieving virological suppression after a pVL rebound was not associated with the magnitude of the rebound [odds ratio (OR), 0.86; P = 0.56] but was associated with triple therapy (OR, 2.22; P = 0.06) or non-adherence (OR, 0.40; P = 0.04). The probability of virological success at week 52 was not associated with an isolated pVL rebound but was less likely after detectable pVL at two consecutive visits. An isolated pVL rebound was not associated with virological success at 52 weeks but rebounds at two consecutive visits decreased the probability of later virological success. Given their high risk of short-term virological failure, patients who present with consecutive detectable pVL measurements following complete suppression should be considered ideal candidates for intervention studies.

Hypothenar hammer syndrome and basilic bypass.

PubMed

Chander, R K; Phair, J; Oza, P; Patel, M; Balar, N

2014-12-01

We report a case of hypothenar hammer syndrome. The case presents necessary diagnostic measures and discusses the etiology of this syndrome. Additionally, the case reviews treatments, which culminated in the eventual use of ulnar artery bypass with autogenous basilica vein to treat and resolve the ischemic fingers of the patient. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Ethnicity predicts viral rebound after travel to the tropics in HIV-infected travelers to the tropics in the Swiss HIV Cohort Study.

PubMed

Gebreselassie, H M; Kraus, D; Fux, C A; Haubitz, S; Scherrer, A; Hatz, C; Veit, O; Stoeckle, M; Fehr, J; de Lucia, S; Cavassini, M; Bernasconi, E; Schmid, P; Furrer, H; Staehelin, C

2017-09-01

The number of HIV-infected individuals from developed countries travelling to tropical and subtropical areas has increased as a result of the clinical and survival benefits of combination antiretroviral therapy. The aim of our study was to describe the traveler population in the SHCS and to determine the frequency of viral rebound in virologically suppressed individuals after a travel episode to the tropics compared to non-travelers. Swiss HIV Cohort Study participants with at least one follow-up visit between 1 January 1989 and 28 February 2015 were eligible for inclusion in the study. The primary outcome was the occurrence of viral rebound (viral load > 200 HIV-1 RNA copies/mL) after a travel episode compared with a nontravel episode in previously suppressed individuals (≤ 200 copies/mL). All virologically suppressed patients contributed multiple travel or nontravel episodes to the analysis. Logistic regression was performed including factors associated with viral rebound. We included 16 635 patients in the study, of whom 6084 (36.5%) had ever travelled to the tropics. Travel frequency increased over time, with travellers showing better HIV parameters than nontravellers [less advanced Centers for Disease Control and Prevention (CDC) stage and higher CD4 count nadir]. Viral rebound was seen in 477 (3.9%) of 12 265 travel episodes and in 5121 (4.5%) of 114 884 nontravel episodes [unadjusted odds ratio (OR) 0.87; 95% confidence interval (CI) 0.78-0.97]. Among these 477 post-travel viral rebounds, 115 had a resistance test performed and 51 (44%) of these showed new resistance mutations. Compared with European and North American patients, the odds for viral rebound were significantly lower in Southeast Asian (OR 0.67; 95% CI 0.51-0.88) and higher in sub-Saharan African (SSA) patients (OR 1.41; 95% CI 1.22-1.62). Travel further increased the odds of viral rebound in SSA patients (OR 2.00; 95% CI 1.53-2.61). Region of origin is the main risk factor for viral rebound

Measuring impact rebound with photography.

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

Sumali, Hartono

2010-05-01

To study the rebound of a sphere colliding against a flat wall, a test setup was developed where the sphere is suspended with strings as a pendulum, elevated, and gravity-released to impact the wall. The motion of the sphere was recorded with a highspeed camera and traced with an image-processing program. From the speed of the sphere before and after each collision, the coefficient of restitution was computed, and shown to be a function of impact speed as predicted analytically.

Air distribution system with the discharge action in the working cavity of downhole air hammer drills

NASA Astrophysics Data System (ADS)

Timonin, VV; Alekseev, SE; Kokoulin, DI; Kubanychbek, B.

2018-03-01

It is proposed to carry out pre-mine methane drainage using underground degassing holes made by downhole air hammer drills. The features of downhole air drills are described. The downhole air drill layout with the simple-shape striking part is presented with its pluses and minuses. The researchers point at available options to eliminate the shortcomings. The improved layout of the downhole air hammer drill is suggested. The paper ends with the test data on the prototype air hammer drill, its characteristics and trial drilling results.

Weathering Grade Classification of Granite Stone Monument Using Reflectance Spectroscopy

NASA Astrophysics Data System (ADS)

Hyun, C.; Roh, T.; Choi, M.; Park, H.

2009-05-01

Stone monument has been placed in field and exposed to rain and wind. This outdoor environment and air pollution induced weathering of stone monument. Weathering grade classification is necessary to manage and conserve stone monuments. Visual interpretation by geologist and laboratory experiments using specimens fallen off from the monument to avoid damage on the monument have been applied to classify weathering grade conventionally. Rocks and minerals absorb some particular wavelength ranges of electromagnetic energy by electronic process and vibrational process of composing elements and these phenomena produce intrinsic diagnostic spectral reflectance curve. Non-destructive technique for weathering degree assessment measures those diagnostic absorption features of weathering products and converts the depths of features related to abundance of the materials to relative weathering degree. We selected granite outcrop to apply conventional six folded weathering grade classification method using Schmidt hammer rebound teste. The correlations between Schmidt hammer rebound values and absorption depths of iron oxides such as ferric oxide in the vicinity of 0.9 micrometer wavelength and clay minerals such as illite and kaolinite in the vicinity of 2.2 micrometer wavelength, representative weathering products of granite, were analyzed. The Schmidt hammer rebound value decreased according to increase of absorption depths induced from those weathering products. Weathering grade classification on the granite stone monument was conducted by using absorption depths of weathering products This research is supported from National Research Institute of Cultural Heritage and we appreciate for this.

Numerical and in-situ investigations of water hammer effects in Drava river Kaplan turbine hydropower plants

NASA Astrophysics Data System (ADS)

Bergant, A.; Gregorc, B.; Gale, J.

2012-11-01

This paper deals with critical flow regimes that may induce unacceptable water hammer in Kaplan turbine hydropower plants. Water hammer analysis should be performed for normal, emergency and catastrophic operating conditions. Hydropower plants with Kaplan turbines are usually comprised of relatively short inlet and outlet conduits. The rigid water hammer theory can be used for this case. For hydropower plants with long penstocks the elastic water hammer should be used. Some Kaplan turbine units are installed in systems with long open channels. In this case, water level oscillations in the channels should be carefully investigated. Computational results are compared with results of measurements in recently rehabilitated seven Drava river hydroelectric power plants in Slovenia. Water hammer in the six power plants is controlled by appropriate adjustment of the wicket gates and runner blades closing/opening manoeuvres. Due to very long inflow and outflow open channels in Zlatoličje HPP a special vaned pressure regulating device attenuates extreme pressures in Kaplan turbine flow-passage system and controls unsteady flow in both open channels. Comparisons of results include normal operating regimes. The agreement between computed and measured results is reasonable.

Heating Capacity of ReBound Shortwave Diathermy and Moist Hot Packs at Superficial Depths

PubMed Central

Hawkes, Amanda R.; Draper, David O.; Johnson, A. Wayne; Diede, Mike T.; Rigby, Justin H.

2013-01-01

Context: The effectiveness of a new continuous diathermy unit, ReBound, as a heating modality is unknown. Objective: To compare the effects of ReBound diathermy with silicate-gel moist hot packs on tissue temperature in the human triceps surae muscle. Design:  Crossover study. Setting: University research laboratory. Patients or Other Participants: A total of 12 healthy, college-aged volunteers (4 men, 8 women; age = 22.2 ± 2.25 years, calf subcutaneous fat thickness = 7.2 ± 1.9 mm). Intervention(s): On 2 different days, 1 of 2 modalities (ReBound diathermy, silicate-gel moist hot pack) was applied to the triceps surae muscle of each participant for 30 minutes. After 30 minutes, the modality was removed, and temperature decay was recorded for 20 minutes. Main Outcome Measure(s):  Medial triceps surae intramuscular tissue temperature at a depth of 1 cm was measured using an implantable thermocouple inserted horizontally into the muscle. Measurements were taken every 5 minutes during the 30-minute treatment and every minute during the 20-minute temperature decay, for a total of 50 minutes. Treatment was analyzed through a 2 × 7 mixed-model analysis of variance with repeated measures. Temperature decay was analyzed through a 2 × 21 mixed-model analysis of variance with repeated measures. Results: During the 30-minute application, tissue temperatures at a depth of 1 cm increased more with the ReBound diathermy than with the moist hot pack (F6,66 = 7.14, P < .001). ReBound diathermy and moist hot packs increased tissue temperatures 3.69°C ± 1.50°C and 2.82°C ± 0.90°C, respectively, from baseline. Throughout the temperature decay, ReBound diathermy produced a greater rate of heat dissipation than the moist hot pack (F20,222 = 4.42, P < .001). Conclusions: During a 30-minute treatment at a superficial depth, the ReBound diathermy increased tissue temperature to moderate levels, which were greater than the levels reached with moist hot packs. PMID:23855362

Determine the Compressive Strength of Calcium Silicate Bricks by Combined Nondestructive Method

PubMed Central

2014-01-01

The paper deals with the application of combined nondestructive method for assessment of compressive strength of calcium silicate bricks. In this case, it is a combination of the rebound hammer method and ultrasonic pulse method. Calibration relationships for determining compressive strength of calcium silicate bricks obtained from nondestructive parameter testing for the combined method as well as for the L-type Schmidt rebound hammer and ultrasonic pulse method are quoted here. Calibration relationships are known for their close correlation and are applicable in practice. The highest correlation between parameters from nondestructive measurement and predicted compressive strength is obtained using the SonReb combined nondestructive method. Combined nondestructive SonReb method was proved applicable for determination of compressive strength of calcium silicate bricks at checking tests in a production plant and for evaluation of bricks built in existing masonry structures. PMID:25276864

Postoperative rebound of antiblood type antibodies and antibody-mediated rejection after ABO-incompatible living-related kidney transplantation.

PubMed

Ishida, Hideki; Kondo, Tsunenori; Shimizu, Tomokazu; Nozaki, Taiji; Tanabe, Kazunari

2015-03-01

The purpose of this study is to examine whether postoperative antiblood type antibody rebound is attributed to kidney allograft rejection in ABO blood type-incompatible (ABO-I) living-related kidney transplantation (KTx). A total of 191 ABO-I recipients who received ABO-I living-related KTx between 2001 and 2013 were divided into two groups: Group 1 consisted of low rebound [(≦1:32), N = 170] and Group 2 consisted of high rebound [(≧1:64), N = 21], according to the levels of the rebounded antiblood type antibodies within 1 year after transplantation. No prophylactic treatment for rejection was administered for elevated antiblood type antibodies, regardless of the levels of the rebounded antibodies. Within 1 year after transplantation, T-cell-mediated rejection was observed in 13 of 170 recipients (13/170, 8%) in Group 1 and in 2 of 21 recipients (2/21, 10%) in Group 2 (Groups 1 vs. 2, P = 0.432). Antibody-mediated rejection was observed in 15 of 170 recipients (15/170, 9%) and 2 of 21 recipients (2/21, 10%) in Groups 1 and 2, respectively (P = 0.898). In this study, we found no correlation between the postoperative antiblood type antibody rebound and the incidence of acute rejection. We concluded that no treatment is necessary for rebounded antiblood type antibodies. © 2014 Steunstichting ESOT.

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

KSC's Director of Public Affairs Joe Gordon (left) applauds as Ed Gormel and Chris Fairey are named recipients of the Hammer Award at a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex. Presenting the award is Morley Winograd (at the podium), director of the National Partnership for Reinventing Government. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel and Fairey are co-chairs of the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base.

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

Commander of the Air Force Space Command, General Richard B. Myers (left) joins Ed Gormel (center) and Commander of the 45th Space Wing Brig. Gen. F. Randall Starbuck (right) after the presentation of the Hammer Award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. Morley Winograd, director of the National Partnership for Reinventing Government, presented the award to the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel is a co-chair of the SEB. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the J-BOSC SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base.

Pressure and wall shear stress in blood hammer - Analytical theory.

PubMed

Mei, Chiang C; Jing, Haixiao

2016-10-01

We describe an analytical theory of blood hammer in a long and stiffened artery due to sudden blockage. Based on the model of a viscous fluid in laminar flow, we derive explicit expressions of oscillatory pressure and wall shear stress. To examine the effects on local plaque formation we also allow the blood vessel radius to be slightly nonuniform. Without resorting to discrete computation, the asymptotic method of multiple scales is utilized to deal with the sharp contrast of time scales. The effects of plaque and blocking time on blood pressure and wall shear stress are studied. The theory is validated by comparison with existing water hammer experiments. Copyright © 2016. Published by Elsevier Inc.

The measurement of intraocular pressure over positive soft contact lenses by rebound tonometry.

PubMed

Zeri, Fabrizio; De Cusatis, Mario; Lupelli, Luigi; Swann, Peter Graham

2016-01-01

To investigate if the accuracy of intraocular pressure (IOP) measurements using rebound tonometry over disposable hydrogel (etafilcon A) contact lenses (CL) is affected by the positive power of the CLs. The experimental group comprised 26 subjects, (8 male, 18 female). IOP measurements were undertaken on the subjects' right eyes in random order using a Rebound Tonometer (ICare). The CLs had powers of +2.00D and +6.00D. Measurements were taken over each contact lens and also before and after the CLs had been worn. The IOP measure obtained with both CLs was significantly lower compared to the value without CLs (t test; p<0.001) but no significant difference was found between the two powers of CLs. Rebound tonometry over positive hydrogel CLs leads to a certain degree of IOP underestimation. This result did not change for the two positive lenses used in the experiment, despite their large difference in power and therefore in lens thickness. Optometrists should bear this in mind when measuring IOP with the rebound tonometer over plus power contact lenses. Copyright © 2016 The Authors. Published by Elsevier Espana.. All rights reserved.

Application of air hammer drilling technology in igneous rocks of Junggar basin

NASA Astrophysics Data System (ADS)

Zhao, Hongshan; Feng, Guangtong; Yu, Haiye

2018-03-01

There were many technical problems such as serious well deviation, low penetration rate and long drilling cycle in igneous rocks because of its hardness, strong abrasive and poor drillability, which severely influenced the exploration and development process of Junggar basin. Through analyzing the difficulties of gas drilling with roller bits in Well HS 2, conducting the mechanics experiments about igneous rock, and deeply describing the rock-breaking mechanism of air hammer drilling and its adaptability in igneous rocks, air hammer drilling can realize deviation control and fast drilling in igneous rocks of piedmont zone and avoid the wear and fatigue fracture of drilling strings due to its characteristics of low WOB, low RPM and high frequency impact. Through firstly used in igneous rocks of Well HS 201, compared with gas drilling with cone bit, the average penetration rate and one-trip footage of air hammer drilling respectively increased by more than 2.45 times and 6.42 times while the well deviation was always controlled less than 2 degrees. Two records for Block HS were set up such as the fastest penetration rate of 14.29m/h in Φ444.5mm well hole and the highest one-trip footage of 470.62m in Φ311.2mm well hole. So air hammer drilling was an effective way to realize optimal and fast drilling in the igneous rock formation of Junggar basin.

ostglacial rebound from VLBI Geodesy: On Establishing Vertical Reference

NASA Technical Reports Server (NTRS)

Argus, Donald .

1996-01-01

I propose that a useful reference frame for vertical motions is that found by minimizing differences between vertical motions observed with VLBI [Ma and Ryan, 1995] and predictions from postglacial rebound predictions [Peltier, 1995].

Do Methodological Choices in Environmental Modeling Bias Rebound Effects? A Case Study on Electric Cars.

PubMed

Font Vivanco, David; Tukker, Arnold; Kemp, René

2016-10-18

Improvements in resource efficiency often underperform because of rebound effects. Calculations of the size of rebound effects are subject to various types of bias, among which methodological choices have received particular attention. Modellers have primarily focused on choices related to changes in demand, however, choices related to modeling the environmental burdens from such changes have received less attention. In this study, we analyze choices in the environmental assessment methods (life cycle assessment (LCA) and hybrid LCA) and environmental input-output databases (E3IOT, Exiobase and WIOD) used as a source of bias. The analysis is done for a case study on battery electric and hydrogen cars in Europe. The results describe moderate rebound effects for both technologies in the short term. Additionally, long-run scenarios are calculated by simulating the total cost of ownership, which describe notable rebound effect sizes-from 26 to 59% and from 18 to 28%, respectively, depending on the methodological choices-with favorable economic conditions. Relevant sources of bias are found to be related to incomplete background systems, technology assumptions and sectorial aggregation. These findings highlight the importance of the method setup and of sensitivity analyses of choices related to environmental modeling in rebound effect assessments.

Computerized Hammer Sounding Interpretation for Concrete Assessment with Online Machine Learning.

PubMed

Ye, Jiaxing; Kobayashi, Takumi; Iwata, Masaya; Tsuda, Hiroshi; Murakawa, Masahiro

2018-03-09

Developing efficient Artificial Intelligence (AI)-enabled systems to substitute the human role in non-destructive testing is an emerging topic of considerable interest. In this study, we propose a novel hammering response analysis system using online machine learning, which aims at achieving near-human performance in assessment of concrete structures. Current computerized hammer sounding systems commonly employ lab-scale data to validate the models. In practice, however, the response signal patterns can be far more complicated due to varying geometric shapes and materials of structures. To deal with a large variety of unseen data, we propose a sequential treatment for response characterization. More specifically, the proposed system can adaptively update itself to approach human performance in hammering sounding data interpretation. To this end, a two-stage framework has been introduced, including feature extraction and the model updating scheme. Various state-of-the-art online learning algorithms have been reviewed and evaluated for the task. To conduct experimental validation, we collected 10,940 response instances from multiple inspection sites; each sample was annotated by human experts with healthy/defective condition labels. The results demonstrated that the proposed scheme achieved favorable assessment accuracy with high efficiency and low computation load.

Become Involved with Someone Who Is on the Rebound?: How Fast Should You Run?

ERIC Educational Resources Information Center

Knox, David; Zusman, Marty E.

2009-01-01

Analysis of survey data from 1002 undergraduates at a large southeastern university revealed differences between the 535 or 53.4% who had become involved (while on the rebound from a previous love relationship) in a new relationship compared to 316 or 31.5% who had not become involved in a new relationship while on the rebound. A profile of the…

A Universal Rig for Supporting Large Hammer Drills: Reduced Injury Risk and Improved Productivity

PubMed Central

Rempel, David; Barr, Alan

2015-01-01

Drilling holes into concrete with heavy hammer and rock drills is one of the most physically demanding tasks performed in commercial construction and poses risks for musculoskeletal disorders, noise induced hearing loss, hand arm vibration syndrome and silicosis. The aim of this study was to (1) use a participatory process to develop a rig to support pneumatic rock drills or large electric hammer drills in order to reduce the health risks and (2) evaluate the usability of the rig. Seven prototype rigs for supporting large hammer drills were developed and modified with feedback from commercial contractors and construction workers. The final design was evaluated by laborers and electricians (N=29) who performed their usual concrete drilling with the usual method and the new rig. Subjective regional fatigue was significantly less in the neck, shoulders, hands and arms, and lower back) when using the universal rig compared to the usual manual method. Usability ratings for the rig were significantly better than the usual method on stability, control, drilling, accuracy, and vibration. Drilling time was reduced by approximately 50% with the rig. Commercial construction contractors, laborers and electricians who use large hammer drills for drilling many holes should consider using such a rig to prevent musculoskeletal disorders, fatigue, and silicosis. PMID:26005290

Percussive Augmenter of Rotary Drills for Operating as a Rotary-Hammer Drill

NASA Technical Reports Server (NTRS)

Aldrich, Jack Barron (Inventor); Bar-Cohen, Yoseph (Inventor); Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bao, Xiaoqi (Inventor); Scott, James Samson (Inventor)

2014-01-01

A percussive augmenter bit includes a connection shaft for mounting the bit onto a rotary drill. In a first modality, an actuator percussively drives the bit, and an electric slip-ring provides power to the actuator while being rotated by the drill. Hammering action from the actuator and rotation from the drill are applied directly to material being drilled. In a second modality, a percussive augmenter includes an actuator that operates as a hammering mechanism that drives a free mass into the bit creating stress pulses that fracture material that is in contact with the bit.

The remarkable environmental rebound effect of electric cars: a microeconomic approach.

PubMed

Font Vivanco, David; Freire-González, Jaume; Kemp, René; van der Voet, Ester

2014-10-21

This article presents a stepwise, refined, and practical analytical framework to model the microeconomic environmental rebound effect (ERE) stemming from cost differences of electric cars in terms of changes in multiple life cycle environmental indicators. The analytical framework is based on marginal consumption analysis and hybrid life cycle assessment (LCA). The article makes a novel contribution through a reinterpretation of the traditional rebound effect and methodological refinements. It also provides novel empirical results about the ERE for plug-in hybrid electric (PHE), full-battery electric (FBE), and hydrogen fuel cell (HFC) cars for Europe. The ERE is found to have a remarkable impact on product-level environmental scores. For the PHE car, the ERE causes a marginal increase in demand and environmental pressures due to a small decrease in the cost of using this technology. For FBE and HFC cars, the high capital costs cause a noteworthy decrease in environmental pressures for some indicators (negative rebound effect). The results corroborate the concern over the high influence of cost differences for environmental assessment, and they prompt sustainable consumption policies to consider markets and prices as tools rather than as an immutable background.

31. FORGE, ANVIL, POWER FORGE HAMMER (FRONT TO BACK), AND ...

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

31. FORGE, ANVIL, POWER FORGE HAMMER (FRONT TO BACK), AND DOORWAY INTO MAIN SHOP-LOOKING SOUTHWEST. - W. A. Young & Sons Foundry & Machine Shop, On Water Street along Monongahela River, Rices Landing, Greene County, PA

Linear or Rotary Actuator Using Electromagnetic Driven Hammer as Prime Mover

NASA Technical Reports Server (NTRS)

McMahan, Bert K. (Inventor); Sesler, Joshua J. (Inventor); Paine, Matthew T. (Inventor); McMahan, Mark C. (Inventor); Paine, Jeffrey S. N. (Inventor); Smith, Byron F. (Inventor)

2018-01-01

We claim a hammer driven actuator that uses the fast-motion, low-force characteristics of an electro-magnetic or similar prime mover to develop kinetic energy that can be transformed via a friction interface to produce a higher-force, lower-speed linear or rotary actuator by using a hammering process to produce a series of individual steps. Such a system can be implemented using a voice-coil, electro-mechanical solenoid or similar prime mover. Where a typical actuator provides limited range of motion or low force, the range of motion of a linear or rotary impact driven motor can be configured to provide large displacements which are not limited by the characteristic dimensions of the prime mover.

Evaluation of monkey intraocular pressure by rebound tonometer

PubMed Central

Yu, Wenhan; Cao, Guiqun; Qiu, Jinghua; Ma, Jia; Li, Ni; Yu, Man; Yan, Naihong; Chen, Lei; Pang, Iok-Hou

2009-01-01

Purpose To evaluate the usefulness of the TonoVet™ rebound tonometer in measuring intraocular pressure (IOP) of monkeys. Methods The accuracy of the TonoVet™ rebound tonometer was determined in cannulated eyes of anesthetized rhesus monkeys where IOP was controlled by adjusting the height of a connected perfusate reservoir. To assess the applicability of the equipment through in vivo studies, the diurnal fluctuation of IOP and effects of IOP-lowering compounds were evaluated in monkeys. Results IOP readings generated by the TonoVet™ tonometer correlated very well with the actual pressure in the cannulated monkey eye. The linear correlation had a slope of 0.922±0.014 (mean±SEM, n=4), a y-intercept of 3.04±0.61, and a correlation coefficient of r2=0.97. Using this method, diurnal IOP fluctuation of the rhesus monkey was demonstrated. The tonometer was also able to detect IOP changes induced by pharmacologically active compounds. A single topical ocular instillation (15 μg) of the rho kinase inhibitor, H1152, produced a 5–6 mmHg reduction (p<0.001) in IOP, lasting at least 4 h. In addition, topical administration of Travatan®, a prostaglandin agonist, induced a small transient IOP increase (1.1 mmHg versus vehicle control; p=0.26) at 2 h after treatment followed by a pressure reduction at 23 h (−2.4 mmHg; p<0.05). Multiple daily dosing with the drug produced a persistent IOP-lowering effect. Three consecutive days of Travatan treatment produced ocular hypotension of −2.0 to −2.2 mmHg (p<0.05) the following day. Conclusions The rebound tonometer was easy to use and accurately measured IOP in the rhesus monkey eye. PMID:19898690

Stable sonoluminescence within a water hammer tube.

PubMed

Chakravarty, Avik; Georghiou, Theo; Phillipson, Tacye E; Walton, Alan J

2004-06-01

The sonoluminescence (SL) from the collapse of a single gas bubble within a liquid can be produced repetitively using an acoustic resonator. An alternative technique using a water hammer tube, producing SL from bubbles of greater size, is described here. A sealed vertical tube partly filled with a liquid and a gas at low pressure is subjected to vertical vibrations. The oscillation of the pressure within the liquid column, due to inertial forces, excites cavitation bubbles to grow and collapse. Rotation is used to confine the bubbles to the axis of the tube. Bright SL emissions were observed in a number of liquids. Repetitive emission was produced from bubbles in condensed phosphoric acid. Bubbles of 0.4 mm ambient radius (containing 2x 10(14) xenon atoms) were excited by vibration at 35 Hz. Approximately 10(12) photons were emitted per collapse in the range 400-700 nm (over four orders of magnitude greater than the brightest SL reported previously), corresponding to a 1% efficiency of the conversion of mechanical energy into light.

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

At a special presentation of the Hammer Award in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, former Apollo astronauts Neil Armstrong (left) and Edwin 'Buzz' Aldrin (second from right) applauded the recipients, Kennedy Space Center and the 45th Space Wing. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Ed Gormel and Chris Fairey, co-chairs of the SEB, accepted the awards for the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base. Armstrong and Aldrin were at KSC to attend a banquet and other activities for the 30th anniversary of the Apollo 11 mission, which landed the first man on the moon.

Cultural differences in the correction of social inferences: Does the dispositional rebound occur in an interdependent culture?

PubMed

Geeraert, Nicolas; Yzerbyt, Vincent Y

2007-06-01

Although social observers have been found to rely heavily on dispositions in their causal analysis, it has been proposed that culture strongly affects this tendency. Recent research has shown that suppressing dispositional inferences during social judgment can lead to a dispositional rebound, that is relying more on dispositional information in subsequent judgments. In the present research, we investigated whether culture also affects this rebound tendency. First, Thai and Belgian participants took part in a typical attitude attribution paradigm. Next, dispositional rebound was assessed by having participants describe a series of pictures. The dispositional rebound occurred for both Belgian and Thai participants when confronted with a forced target, but disappeared for Thai participants when the situational constraints of the target were made salient. The findings are discussed in light of the current cultural models of attribution theory.

Comparing the magnitude of simulated residential rebound effects from electric end-use efficiency across the US

NASA Astrophysics Data System (ADS)

Thomas, Brinda A.; Hausfather, Zeke; Azevedo, Inês L.

2014-07-01

Many US states rely on energy efficiency goals as a strategy to reduce CO2e emissions and air pollution, to minimize investments in new power plants, and to create jobs. For those energy efficiency interventions that are cost-effective, i.e., saving money and reducing energy, consumers may increase their use of energy services, or re-spend cost savings on other carbon- and energy-intensive goods and services. In this paper, we simulate the magnitude of these ‘rebound effects’ in each of the 50 states in terms of CO2e emissions, focusing on residential electric end-uses under plausible assumptions. We find that a 10% reduction in annual electricity use by a household results in an emissions’ reduction penalty ranging from 0.1 ton CO2e in California to 0.3 ton CO2e in Alabama (from potential emissions reductions of 0.3 ton CO2e and 1.6 ton CO2e, respectively, in the no rebound case). Rebound effects, percentage-wise, range from 6% in West Virginia (which has a high-carbon electricity and low electricity prices), to as high as 40% in California (which has low-carbon electricity and high electricity prices). The magnitude of rebound effects percentage-wise depends on the carbon intensity of the grid: in states with low emissions factors and higher electricity prices, such as California, the rebound effects are much larger percentage-wise than in states like Pennsylvania. Conversely, the states with larger per cent rebound effects are the ones where the implications in terms of absolute emissions changes are the smallest.

Sound Rhythms Are Encoded by Postinhibitory Rebound Spiking in the Superior Paraolivary Nucleus

PubMed Central

Felix, Richard A.; Fridberger, Anders; Leijon, Sara; Berrebi, Albert S.; Magnusson, Anna K.

2013-01-01

The superior paraolivary nucleus (SPON) is a prominent structure in the auditory brainstem. In contrast to the principal superior olivary nuclei with identified roles in processing binaural sound localization cues, the role of the SPON in hearing is not well understood. A combined in vitro and in vivo approach was used to investigate the cellular properties of SPON neurons in the mouse. Patch-clamp recordings in brain slices revealed that brief and well timed postinhibitory rebound spiking, generated by the interaction of two subthreshold-activated ion currents, is a hallmark of SPON neurons. The Ih current determines the timing of the rebound, whereas the T-type Ca2+ current boosts the rebound to spike threshold. This precisely timed rebound spiking provides a physiological explanation for the sensitivity of SPON neurons to sinusoidally amplitude-modulated (SAM) tones in vivo, where peaks in the sound envelope drive inhibitory inputs and SPON neurons fire action potentials during the waveform troughs. Consistent with this notion, SPON neurons display intrinsic tuning to frequency-modulated sinusoidal currents (1–15Hz) in vitro and discharge with strong synchrony to SAMs with modulation frequencies between 1 and 20 Hz in vivo. The results of this study suggest that the SPON is particularly well suited to encode rhythmic sound patterns. Such temporal periodicity information is likely important for detection of communication cues, such as the acoustic envelopes of animal vocalizations and speech signals. PMID:21880918

Sound rhythms are encoded by postinhibitory rebound spiking in the superior paraolivary nucleus.

PubMed

Felix, Richard A; Fridberger, Anders; Leijon, Sara; Berrebi, Albert S; Magnusson, Anna K

2011-08-31

The superior paraolivary nucleus (SPON) is a prominent structure in the auditory brainstem. In contrast to the principal superior olivary nuclei with identified roles in processing binaural sound localization cues, the role of the SPON in hearing is not well understood. A combined in vitro and in vivo approach was used to investigate the cellular properties of SPON neurons in the mouse. Patch-clamp recordings in brain slices revealed that brief and well timed postinhibitory rebound spiking, generated by the interaction of two subthreshold-activated ion currents, is a hallmark of SPON neurons. The I(h) current determines the timing of the rebound, whereas the T-type Ca(2+) current boosts the rebound to spike threshold. This precisely timed rebound spiking provides a physiological explanation for the sensitivity of SPON neurons to sinusoidally amplitude-modulated (SAM) tones in vivo, where peaks in the sound envelope drive inhibitory inputs and SPON neurons fire action potentials during the waveform troughs. Consistent with this notion, SPON neurons display intrinsic tuning to frequency-modulated sinusoidal currents (1-15Hz) in vitro and discharge with strong synchrony to SAMs with modulation frequencies between 1 and 20 Hz in vivo. The results of this study suggest that the SPON is particularly well suited to encode rhythmic sound patterns. Such temporal periodicity information is likely important for detection of communication cues, such as the acoustic envelopes of animal vocalizations and speech signals.

5. VIEW OF 20TON STEAMPOWERED FORGE HAMMER Manufactured by Chambersburg ...

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

5. VIEW OF 20-TON STEAM-POWERED FORGE HAMMER Manufactured by Chambersburg Engineering Company, Chambersburg, Pennsylvania - Juniata Shops, Blacksmith Shop No. 1, East of Fourth Avenue at Second Street, Altoona, Blair County, PA

Rebounding droplet-droplet collisions on superhydrophobic surfaces: from the phenomenon to droplet logic.

PubMed

Mertaniemi, Henrikki; Forchheimer, Robert; Ikkala, Olli; Ras, Robin H A

2012-11-08

When water droplets impact each other while traveling on a superhydrophobic surface, we demonstrate that they are able to rebound like billiard balls. We present elementary Boolean logic operations and a flip-flop memory based on these rebounding water droplet collisions. Furthermore, bouncing or coalescence can be easily controlled by process parameters. Thus by the controlled coalescence of reactive droplets, here using the quenching of fluorescent metal nanoclusters as a model reaction, we also demonstrate an elementary operation for programmable chemistry. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The hammer QSD-quick stop device for high speed machining and rubbing

NASA Technical Reports Server (NTRS)

Black, J. T.; James, C. R.

1980-01-01

A quick stop device (QSD) was designed for use in orthogonal machining and rubbing experiments. QSD's are used to obtain chip root samples that are representative of the deformation taking place during dynamic (actual) cutting conditions. These 'frozen' specimens are helpful in examining the plastic deformation that occurs in the regions of compression and shear which form the chip; the secondary shear at the tool-chip interface; and the nose ploughing/flank rubbing action which operates on the newly machined surface. The Hammer QSD employs a shear pin mechanism, broken by a flying hammer, which is traveling at the same velocity as the workpiece. The device has been successfully tested up to 6000 sfpm (30.48 m/sec).

A comparison of VLBI with the ICE-3G glacial rebound model

NASA Technical Reports Server (NTRS)

James, Thomas S.; Lambert, Anthony

1993-01-01

Crustal motion predicted by the ICE-3G glacial rebound model exhibits a pattern of tangential (horizontal) divergence away from the centers of uplift, which in North America and Europe are located around Hudson Bay and the Gulf of Bothnia. Tangential velocities reach peak magnitudes of 1-2 mm/yr, and must be included when predicting VLBI baseline length change rates due to postglacial rebound. Out of 18 observed VLBI baselines examined three are situated such that their predicted length rates are around their 2 sigma uncertainties or greater. It is encouraging that two of these baselines exhibit predicted length rates within 2 sigma of the observed rates.

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

At a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, the Hammer Award is presented to Kennedy Space Center and the 45th Space Wing. Among the attendees in the audience are (center) Center Director Roy D. Bridges Jr., flanked by (at left) Commander of the 45th Space Wing Brig. Gen. F. Randall Starbuck and (at right) Commander of the Air Force Space Command General Richard B. Myers. Standing second from right is NASA Administrator Daniel S. Goldin. At the far right is Morley Winograd, director of the National Partnership for Reinventing Government, who presented the award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J- BOSC) Source Evaluation Board (SEB). Ed Gormel and Chris Fairey, co-chairs of the SEB, accepted the awards for the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base.

Cavitation luminescence in a water hammer: Upscaling sonoluminescence

NASA Astrophysics Data System (ADS)

Su, C.-K.; Camara, C.; Kappus, B.; Putterman, S. J.

2003-06-01

Oscillatory acceleration and deceleration of a column of water leads to a pipe hammer as well as cavitation. With a small amount of xenon gas dissolved in the water, we can detect a stream of predominantly ultraviolet subnanosecond flashes of light which are attributed to collapsing bubbles. The observed emission can exceed 108 photons for a single collapse and has a peak power over 0.4 W.

Sliding pressure control valve for pneumatic hammer drill

DOEpatents

Polsky, Yarom [Albuquerque, NM

2011-08-30

A pneumatic device control apparatus and method comprising a ported valve slidably fitted over a feed tube of the pneumatic device, and using a compliant biasing device to constrain motion of the valve to provide asymmetric timing for extended pressurization of a power chamber and reduced pressurization of a return chamber of the pneumatic device. The pneumatic device can be a pneumatic hammer drill.

Plasma HIV viral rebound following protocol-indicated cessation of ART commenced in primary and chronic HIV infection.

PubMed

Hamlyn, Elizabeth; Ewings, Fiona M; Porter, Kholoud; Cooper, David A; Tambussi, Giuseppe; Schechter, Mauro; Pedersen, Court; Okulicz, Jason F; McClure, Myra; Babiker, Abdel; Weber, Jonathan; Fidler, Sarah

2012-01-01

The magnitude of HIV viral rebound following ART cessation has consequences for clinical outcome and onward transmission. We compared plasma viral load (pVL) rebound after stopping ART initiated in primary (PHI) and chronic HIV infection (CHI). Two populations with protocol-indicated ART cessation from SPARTAC (PHI, n = 182) and SMART (CHI, n = 1450) trials. Time for pVL to reach pre-ART levels after stopping ART was assessed in PHI using survival analysis. Differences in pVL between PHI and CHI populations 4 weeks after stopping ART were examined using linear and logistic regression. Differences in pVL slopes up to 48 weeks were examined using linear mixed models and viral burden was estimated through a time-averaged area-under-pVL curve. CHI participants were categorised by nadir CD4 at ART stop. Of 171 PHI participants, 71 (41.5%) rebounded to pre-ART pVL levels, at a median of 50 (95% CI 48-51) weeks after stopping ART. Four weeks after stopping treatment, although the proportion with pVL ≥ 400 copies/ml was similar (78% PHI versus 79% CHI), levels were 0.45 (95% CI 0.26-0.64) log(10) copies/ml lower for PHI versus CHI, and remained lower up to 48 weeks. Lower CD4 nadir in CHI was associated with higher pVL after ART stop. Rebound for CHI participants with CD4 nadir >500 cells/mm(3) was comparable to that experienced by PHI participants. Stopping ART initiated in PHI and CHI was associated with viral rebound to levels conferring increased transmission risk, although the level of rebound was significantly lower and sustained in PHI compared to CHI.

Improved ATLAS HammerCloud Monitoring for Local Site Administration

NASA Astrophysics Data System (ADS)

Böhler, M.; Elmsheuser, J.; Hönig, F.; Legger, F.; Mancinelli, V.; Sciacca, G.

2015-12-01

Every day hundreds of tests are run on the Worldwide LHC Computing Grid for the ATLAS, and CMS experiments in order to evaluate the performance and reliability of the different computing sites. All this activity is steered, controlled, and monitored by the HammerCloud testing infrastructure. Sites with failing functionality tests are auto-excluded from the ATLAS computing grid, therefore it is essential to provide a detailed and well organized web interface for the local site administrators such that they can easily spot and promptly solve site issues. Additional functionality has been developed to extract and visualize the most relevant information. The site administrators can now be pointed easily to major site issues which lead to site blacklisting as well as possible minor issues that are usually not conspicuous enough to warrant the blacklisting of a specific site, but can still cause undesired effects such as a non-negligible job failure rate. This paper summarizes the different developments and optimizations of the HammerCloud web interface and gives an overview of typical use cases.

[On vibration hazards of chipping-hammer operators in an iron foundry. Part 2. Results of the hygienic control].

PubMed

Harada, N; Matsumoto, T; Yamada, S; Kobayashi, F

1982-01-01

We previously reported that the working and health conditions of vibrating tool operators in an iron foundry were investigated in 1975 and vibration hazards were observed to occur frequently in workers operating chipping-hammers powered by compressed air. After that, we instituted medical treatment for the afflicted workers and improvement of working conditions in the foundry, and have performed annual medical examinations for four years. In this paper, the course of hygienic control and the change in the medical findings of twenty-four chipping-hammer operators are reported. 1. The following measures were taken to improve the working conditions of chipping-hammer operators and therapy for patients (Table 1): (1) The operating time of vibrating tools, including chipping-hammer, was limited to two hours per day. The casting process was improved to diminish the flashes that are the objects of chipping-hammer operation. For the purpose of reducing the vibration transmitted to the operator, a servo-arm that has a servomechanism for the chipping-hammer was developed and introduced. (2) Infrared lamps in the foundry and air curtains at the doorway were installed for keeping the chipping-hammer operating area warm. A warm room was set up in the foundry for providing warmth during rest periods and protective clothing against the cold was provided. (3) Workers who displayed health disturbances by medical examinations were treated during the cold season from November to April by periodic visits to the clinic or extended hospitalization, or transferred to job without vibration exposure, according to their stage of disease. Preventive treatment with vasodilator and bubble bath was performed in winter for the chipping-hammer operators. 2. In order to estimate the effect of these countermeasures, annual medical examinations were conducted in March 1975, March 1976, April 1977 and March 1978. Such subjective symptoms as Raynaud's phenomenon, finger numbness, finger listlessness

Suppression on your own terms: internally generated displays of craving suppression predict rebound effects.

PubMed

Sayers, W Michael; Sayette, Michael A

2013-09-01

Research on emotion suppression has shown a rebound effect, in which expression of the targeted emotion increases following a suppression attempt. In prior investigations, participants have been explicitly instructed to suppress their responses, which has drawn the act of suppression into metaconsciousness. Yet emerging research emphasizes the importance of nonconscious approaches to emotion regulation. This study is the first in which a craving rebound effect was evaluated without simultaneously raising awareness about suppression. We aimed to link spontaneously occurring attempts to suppress cigarette craving to increased smoking motivation assessed immediately thereafter. Smokers (n = 66) received a robust cued smoking-craving manipulation while their facial responses were videotaped and coded using the Facial Action Coding System. Following smoking-cue exposure, participants completed a behavioral choice task previously found to index smoking motivation. Participants evincing suppression-related facial expressions during cue exposure subsequently valued smoking more than did those not displaying these expressions, which suggests that internally generated suppression can exert powerful rebound effects.

Gaze-evoked and rebound nystagmus in a case of migrainous vertigo.

PubMed

Oh, Sun-Young; Seo, Man-Wook; Kim, Young-Hyun; Choi, Kwang-Dong; Kim, Dae-Seong; Shin, Byoung-Soo

2009-03-01

A patient with migrainous vertigo showed pronounced gaze-evoked and rebound nystagmus during an attack. These findings, which have not been previously documented, suggest that migrainous vertigo is based on central vestibular dysfunction.

Antarctic Rebound and the Time-Dependence of the Earth's Shape

NASA Technical Reports Server (NTRS)

Ivins, Erik R.; James, Thomas S.

2000-01-01

Great strides have been made during the past 30 years in refining models of the last global glaciation. The refinements draw upon a vastly expanded relative sea level and sedimentary core record. Furthermore, we now possess a sharpened understanding of the mechanisms that drive climate changes associated with deglaciation. Some 15 years ago, using only 5.5 years of ranging data, analyses of the drift in LAGEOS I node acceleration was used to infer that postglacial rebound was responsible for a secular change in the Earth's ellipsoidal shape (Yoder et al., .1983]. Today there exists a wealth of geodynamics satellite orbit data that constrain the secular time-dependence of the Earth's shape and low order gravity field, which includes mass redistribution from present-day glacier and great ice sheet imbalance and from postglacial rebound. We have shown that an unambiguous determination of the secular variation in the Earth's pear shaped harmonic (l = 3, m = 0) might provide information that bears on the present-day mass balance of Antarctica. This issue is revisited in light of new constraints on glacial loading during the late-Pleistocene and Holocene. An especially critical issue for the interpretation of secular odd degree zonal harmonics, l = 3 to 7, is the timing and magnitude of the deglaciation of Antarctica from Last Glacial Maximum. We explore ways in which the recovery of secular variation in both zonal and non-zonal harmonics for l = 2 through 7 can improve constraints on both rebound and present-day ice sheet balance.

Postglacial Rebound from VLBI Geodesy: On Establishing Vertical Reference

NASA Technical Reports Server (NTRS)

Argus, Donald F.

1996-01-01

Difficulty in establishing a reference frame fixed to the earth's interior complicates the measurement of the vertical (radial) motions of the surface. I propose that a useful reference frame for vertical motions is that found by minimizing differences between vertical motions observed with VLBI [Ma and Ryan] and predictions from postglacial rebound predictions [Peltier]. The optimal translation of the geocenter is 1.7mm/year toward 36degN, 111degE when determined from the motions of 10 VLBI sites. This translation gives a better fit of observations to predictions than does the VLBI reference frame used by Ma and Ryan, but the improvement is statistically insignificant. The root mean square of differences decreases 20% to 0.73 mm/yr and the correlation coefficient increases from 0.76 to 0.87. Postglacial rebound is evident in the uplift of points in Sweden and Ontario that were beneath the ancient ice sheets of Fennoscandia and Canada, and in the subsidence of points in the northeastern U.S., Germany, and Alaska that were around the periphery of the ancient ice sheets.

Autologous Stem Cell Transplantation Disrupts Adaptive Immune Responses during Rebound Simian/Human Immunodeficiency Virus Viremia.

PubMed

Reeves, Daniel B; Peterson, Christopher W; Kiem, Hans-Peter; Schiffer, Joshua T

2017-07-01

Primary HIV-1 infection induces a virus-specific adaptive/cytolytic immune response that impacts the plasma viral load set point and the rate of progression to AIDS. Combination antiretroviral therapy (cART) suppresses plasma viremia to undetectable levels that rebound upon cART treatment interruption. Following cART withdrawal, the memory component of the virus-specific adaptive immune response may improve viral control compared to primary infection. Here, using primary infection and treatment interruption data from macaques infected with simian/human immunodeficiency virus (SHIV), we observe a lower peak viral load but an unchanged viral set point during viral rebound. The addition of an autologous stem cell transplant before cART withdrawal alters viral dynamics: we found a higher rebound set point but similar peak viral loads compared to the primary infection. Mathematical modeling of the data that accounts for fundamental immune parameters achieves excellent fit to heterogeneous viral loads. Analysis of model output suggests that the rapid memory immune response following treatment interruption does not ultimately lead to better viral containment. Transplantation decreases the durability of the adaptive immune response following cART withdrawal and viral rebound. Our model's results highlight the impact of the endogenous adaptive immune response during primary SHIV infection. Moreover, because we capture adaptive immune memory and the impact of transplantation, this model will provide insight into further studies of cure strategies inspired by the Berlin patient. IMPORTANCE HIV patients who interrupt combination antiretroviral therapy (cART) eventually experience viral rebound, the return of viral loads to pretreatment levels. However, the "Berlin patient" remained free of HIV rebound over a decade after stopping cART. His cure is attributed to leukemia treatment that included an HIV-resistant stem cell transplant. Inspired by this case, we studied the impact

Autologous Stem Cell Transplantation Disrupts Adaptive Immune Responses during Rebound Simian/Human Immunodeficiency Virus Viremia

PubMed Central

Peterson, Christopher W.; Kiem, Hans-Peter

2017-01-01

ABSTRACT Primary HIV-1 infection induces a virus-specific adaptive/cytolytic immune response that impacts the plasma viral load set point and the rate of progression to AIDS. Combination antiretroviral therapy (cART) suppresses plasma viremia to undetectable levels that rebound upon cART treatment interruption. Following cART withdrawal, the memory component of the virus-specific adaptive immune response may improve viral control compared to primary infection. Here, using primary infection and treatment interruption data from macaques infected with simian/human immunodeficiency virus (SHIV), we observe a lower peak viral load but an unchanged viral set point during viral rebound. The addition of an autologous stem cell transplant before cART withdrawal alters viral dynamics: we found a higher rebound set point but similar peak viral loads compared to the primary infection. Mathematical modeling of the data that accounts for fundamental immune parameters achieves excellent fit to heterogeneous viral loads. Analysis of model output suggests that the rapid memory immune response following treatment interruption does not ultimately lead to better viral containment. Transplantation decreases the durability of the adaptive immune response following cART withdrawal and viral rebound. Our model's results highlight the impact of the endogenous adaptive immune response during primary SHIV infection. Moreover, because we capture adaptive immune memory and the impact of transplantation, this model will provide insight into further studies of cure strategies inspired by the Berlin patient. IMPORTANCE HIV patients who interrupt combination antiretroviral therapy (cART) eventually experience viral rebound, the return of viral loads to pretreatment levels. However, the “Berlin patient” remained free of HIV rebound over a decade after stopping cART. His cure is attributed to leukemia treatment that included an HIV-resistant stem cell transplant. Inspired by this case, we

Grinding energy and physical properties of chopped and hammer-milled barley, wheat, oat, and canola straws

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

J.S. Tumuluru; L.G. Tabil; Y. Song

2014-01-01

In the present study, specific energy for grinding and physical properties of wheat, canola, oat and barley straw grinds were investigated. The initial moisture content of the straw was about 0.13–0.15 (fraction total mass basis). Particle size reduction experiments were conducted in two stages: (1) a chopper without a screen, and (2) a hammer mill using three screen sizes (19.05, 25.4, and 31.75 mm). The lowest grinding energy (1.96 and 2.91 kWh t-1) was recorded for canola straw using a chopper and hammer mill with 19.05-mm screen size, whereas the highest (3.15 and 8.05 kWh t-1) was recorded for barleymore » and oat straws. The physical properties (geometric mean particle diameter, bulk, tapped and particle density, and porosity) of the chopped and hammer-milled wheat, barley, canola, and oat straw grinds measured were in the range of 0.98–4.22 mm, 36–80 kg m-3, 49–119 kg m-3, 600–1220 kg m-3, and 0.9–0.96, respectively. The average mean particle diameter was highest for the chopped wheat straw (4.22-mm) and lowest for the canola grind (0.98-mm). The canola grinds produced using the hammer mill (19.05-mm screen size) had the highest bulk and tapped density of about 80 and 119 kg m-3; whereas, the wheat and oat grinds had the lowest of about 58 and 88–90 kg m-3. The results indicate that the bulk and tapped densities are inversely proportional to the particle size of the grinds. The flow properties of the grinds calculated are better for chopped straws compared to hammer milled using smaller screen size (19.05 mm).« less

Influence of pin and hammer mill on grinding characteristics, thermal and antioxidant properties of coriander powder.

PubMed

Barnwal, P; Singh, K K; Sharma, Alka; Choudhary, A K; Saxena, S N

2015-12-01

In present study, influence of grinding (hammer and pin mills) and moisture content (range: 6.4-13.6 % dry basis) on the quality traits of coriander powder were investigated. These include grinding parameters, colour parameters, specific heat, thermal conductivity, thermal diffusivity, glass transition temperature, essential oil, total phenolic content, total flavonoid content and DPPH scavenging (%) of coriander powder. For coriander seed, the geometric properties such as major, medium, minor dimensions, geometric mean diameter, arithmetic mean diameter, sphericity, surface area and volume of coriander seeds increased significantly with increasing moisture (6.4-13.6 % db). For coriander powder, the grinding parameters such as average particle size, volume surface mean diameter and volume mean diameter increased significantly with increasing moisture (6.4-13.6 % db). With the grinding method, the colour attributes of coriander powder such as L-value, a-value, b-value, hue angle and browning index varied significantly. It was observed that the specific heat followed second order polynomial relationship with temperature and moisture whereas thermal conductivity varied linearly with temperature and moisture content. The variation of glass transition temperature with moisture can be best represented in quadratic manner. Total flavonoid content (mg QE/g crude seed extract) and DPPH scavenging % activity of coriander powder is significantly affected by grinding methods. A lower value of specific heat was observed for hammer ground coriander powder as compared to pin mill ground coriander powder. The thermal conductivity of hammer mill ground coriander powder was higher as compared to pin mill ground coriander. It was observed that hammer mill yields more fine coriander powder in comparison to pin mill. The browning index was more in hammer mill ground coriander powder.

REBOUND: A Media-Based Life Skills and Risk Education Programme

ERIC Educational Resources Information Center

Kröninger-Jungaberle, Henrik; Nagy, Ede; von Heyden, Maximilian; DuBois, Fletcher

2015-01-01

Background: REBOUND is a novel media-based life skills and risk education programme developed for 14- to 25-year olds in school, university or youth group settings. This paper outlines the programme's rationale, curriculum and implementation. It provides information of relevance to researchers, programme developers and policymakers. Methods/design…

Testing as a Service with HammerCloud

NASA Astrophysics Data System (ADS)

Medrano Llamas, Ramón; Barrand, Quentin; Elmsheuser, Johannes; Legger, Federica; Sciacca, Gianfranco; Sciabà, Andrea; van der Ster, Daniel

2014-06-01

HammerCloud was designed and born under the needs of the grid community to test the resources and automate operations from a user perspective. The recent developments in the IT space propose a shift to the software defined data centres, in which every layer of the infrastructure can be offered as a service. Testing and monitoring is an integral part of the development, validation and operations of big systems, like the grid. This area is not escaping the paradigm shift and we are starting to perceive as natural the Testing as a Service (TaaS) offerings, which allow testing any infrastructure service, such as the Infrastructure as a Service (IaaS) platforms being deployed in many grid sites, both from the functional and stressing perspectives. This work will review the recent developments in HammerCloud and its evolution to a TaaS conception, in particular its deployment on the Agile Infrastructure platform at CERN and the testing of many IaaS providers across Europe in the context of experiment requirements. The first section will review the architectural changes that a service running in the cloud needs, such an orchestration service or new storage requirements in order to provide functional and stress testing. The second section will review the first tests of infrastructure providers on the perspective of the challenges discovered from the architectural point of view. Finally, the third section will evaluate future requirements of scalability and features to increase testing productivity.

Astronaut David Scott watching hammer and feather fall to lunar surface

NASA Image and Video Library

1971-08-02

S71-43788 (2 Aug. 1971) --- Astronaut David R. Scott, Apollo 15 commander, watches a geological hammer and a feather hit the lunar surface simultaneously in a test of Galileo's law of motion concerning falling bodies, as seen in this color reproduction taken from a transmission made by the RCA color television camera mounted on the Lunar Roving Vehicle (LRV). Scott released the hammer from his right hand and the feather from his left at the same instant. Galileo (1564-1642) was the great Italian astronomer and physicist. This experiment occurred toward the end of the third and final lunar surface extravehicular activity (EVA) by astronauts Scott and James B. Irwin, lunar module pilot. While Scott and Irwin descended in the Lunar Module (LM) to explore the moon, astronaut Alfred M. Worden, command module pilot, remained in the Command and Service Modules (CSM) in lunar orbit.

How to HAMMER home hazardous materials training

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

Ollero, J.

1994-10-01

This article describes HAMMER - the Hazardous Materials Management and Emergency Response Training - program being developed at the Hanford Reservation. The program uses true-to-life props and facilities to simulate emergencies and hazardous conditions. Topics covered include the set-up of the facility and training; the demand for such training; the involvement of the Army Corps of Engineers; the props to be constructed; the educational involvement of Tulane and Xavier Univerisities of Louisiana; temporary facility for the program; partnership with Indian Nations and Stakeholders; and budget plans and constriction. 9 figs.

Measurement and interpretation of crustal deformation rates associated with postglacial rebound

NASA Technical Reports Server (NTRS)

Davis, James L.

1993-01-01

This project involves obtaining Global Positioning System (GPS) measurements in Scandinavia, and using the measurements to estimate the viscosity profile of the Earth's mantle and to correct tide-gage measurements for the rebound effect. Several aspects of this project are reported.

7. VIEW OF HYDRAULIC HAMMER STAMPING PRESS ON SIDE A ...

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

7. VIEW OF HYDRAULIC HAMMER STAMPING PRESS ON SIDE A OF BUILDING 883. THIS TYPE OF PRESS WAS USED FOR BOTH STAINLESS STEEL AND FOR DEPLETED URANIUM. (7/2/86) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

­­Drought, water conservation, and water demand rebound in California

NASA Astrophysics Data System (ADS)

Gonzales, P.; Ajami, N.

2017-12-01

There is growing recognition that dynamic community values, preferences, and water use behaviors are important drivers of water demand in addition to external factors such as temperature and precipitation. Water demand drivers have been extensively studied, yet they have traditionally been applied to models that assume static conditions and usually do not account for potential societal changes in response to increased scarcity awareness. For example, following a period of sustained low demand such as during a drought, communities often increase water use during a hydrologically wet period, a phenomenon known as "rebounding" water use. Yet previous experiences show the extent of this rebound is not a straightforward function of policy and efficiency improvements, but may also reflect short-term or long-lasting change in community behavior, which are not easily captured by models that assume stationarity. In this study we explore cycles of decreased water demand during drought and subsequent water use rebound observed in California in recent decades. We have developed a novel dynamic system model for water demand in three diverse but interconnected service areas in the San Francisco Bay Area, exposing local trends of changing water use behaviors and long-term impacts on water demand since 1980 to the present. In this model, we apply the concept of social memory, defined as a community's inherited knowledge about hazardous events or degraded environmental conditions from past experiences. While this concept has been applied to further conceptual understanding of socio-hydrologic systems in response to hydrological extremes, to the best of our knowledge this the first study to incorporate social memory to model the water demand rebound phenomenon and to use such a model in the examination of changing dynamics validated by historical data. In addition, we take a closer look at water demand during the recent historic drought in California from 2012-16, and relate our

On the prediction of impact noise, V: The noise from drop hammers

NASA Astrophysics Data System (ADS)

Richards, E. J.; Carr, I.; Westcott, M.

1983-06-01

In earlier papers in this series, the concepts of "acceleration" and "ringing" noise have been studied in relation to impact machines, and values of radiation efficiency have been obtained for the various types of structural components. In the work reported in this paper the predicted and measured noise radiation from a drop hammer, both in full-scale and in {1}/{3}- scale model form, were examined. It is found that overall noise levels ( Leq per event) can be predicted from vibration measurements to within ± 1·5 dB, and to within ±2·5 dB in one-third octave bands. In turn this has permitted noise reduction techniques to be examined by studies of local component vibration levels rather than overall noise, a method which provides considerable enlightenment at the design stage. It is shown that on one particular drop hammer, the noise energy is shared surprisingly uniformly over four or five sources, and that when these have been reduced, the overall noise reduction is severely limited by the "acceleration" noise from the "tup" or "hammer" itself. As this is difficult to eliminate without a basic change in forging technology, it follows that "tup" enclosure or modification of the sharpness of the final "hard" impact are the only means available for any serious noise reduction. Also indicated is the reliability of using model techniques, suitably scaled in frequency and impulse magnitude, in developing machinery with impact characteristics.

Plasma HIV-1 RNA viral load rebound among people who inject drugs receiving antiretroviral therapy (ART) in a Canadian setting: an ethno-epidemiological study.

PubMed

Small, Will; Milloy, M J; McNeil, Ryan; Maher, Lisa; Kerr, Thomas

2016-01-01

People who inject drugs (PWID) living with HIV often experience sub-optimal antiretroviral therapy (ART) treatment outcomes, including HIV plasma viral load (PVL) rebound. While previous studies have identified risk factors for PVL rebound among PWID, no study has examined the perspectives of PWID who have experienced PVL rebound episodes. We conducted an ethno-epidemiological study to investigate the circumstances surrounding the emergence of rebound episodes among PWID in Vancouver, BC, Canada. Comprehensive clinical records linked to a community-based prospective observational cohort of HIV-positive drug users were used to identify PWID who had recently experienced viral rebound. In-depth qualitative interviews with 16 male and 11 female participants explored participant perspectives regarding the emergence of viral rebound. A timeline depicting each participant's HIV viral load and adherence to ART was used to elicit discussion of circumstances surrounding viral rebound. Viral rebound episodes were shaped by interplay between various individual, social, and environmental factors that disrupted routines facilitating adherence. Structural-environmental influences resulting in non-adherence included housing transitions, changes in drug use patterns and intense drug scene involvement, and inadequate care for co-morbid health conditions. Social-environmental influences on ART adherence included poor interactions between care providers and patients producing non-adherence, and understandings of HIV treatment that fostered intentional treatment discontinuation. This study describes key pathways which led to rebound episodes among PWID receiving ART and illustrates how environmental forces may increase vulnerability for non-adherence leading to treatment failure. Our findings have potential to help inform interventions and supports that address social-structural forces that foster non-adherence among PWID.

Water hammer reduces fouling during natural water ultrafiltration.

PubMed

Broens, F; Menne, D; Pothof, I; Blankert, B; Roesink, H D W; Futselaar, H; Lammertink, R G H; Wessling, M

2012-03-15

Today's ultrafiltration processes use permeate flow reversal to remove fouling deposits on the feed side of ultrafiltration membranes. We report an as effective method: the opening and rapid closing of a valve on the permeate side of an ultrafiltration module. The sudden valve closure generates pressure fluctuations due to fluid inertia and is commonly known as "water hammer". Surface water was filtrated in hollow fiber ultrafiltration membranes with a small (5%) crossflow. Filtration experiments above sustainable flux levels (>125 l (m2h)(-1)) show that a periodic closure of a valve on the permeate side improves filtration performance as a consequence of reduced fouling. It was shown that this effect depends on flux and actuation frequency of the valve. The time period that the valve was closed proved to have no effect on filtration performance. The pressure fluctuations generated by the sudden stop in fluid motion due to the valve closure are responsible for the effect of fouling reduction. High frequency recording of the dynamic pressure evolution shows water hammer related pressure fluctuations to occur in the order of 0.1 bar. The pressure fluctuations were higher at higher fluxes (higher velocities) which is in agreement with the theory. They were also more effective at higher fluxes with respect to fouling mitigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Social and Structural Patterns of Drought-Related Water Conservation and Rebound

NASA Astrophysics Data System (ADS)

Gonzales, Patricia; Ajami, Newsha

2017-12-01

Water use practices and conservation are the result of complex sociotechnical interactions of political, economic, hydroclimatic, and social factors. While the drivers of water demand have been extensively studied, they have traditionally been applied to models that assume stationary relationships between these various factors, and usually do not account for potential societal changes in response to increased scarcity awareness. For example, following a period of sustained low demand such as during a drought, communities often increase water use during a hydrologically wet period, a phenomenon known as "rebounding" water use. Previous experiences show the extent of this rebound is not a straightforward function of policy and efficiency improvements, but may also reflect short-term or long-lasting change in community behavior, which are not easily captured by models that assume stationarity. In this work, we develop a system dynamics model to represent water demand as a function of both structural and social factors. We apply this model to the analysis of three diverse water utilities in the San Francisco Bay Area between 1980 and 2017, identifying drought response trends and drivers over time. Our model is consistent with empirical patterns and historical context of water use in California, and provides important insights on the rebound phenomenon that can be extended to other locations. This comparative assessment indicates that policies, public outreach, and better data availability have played a key role in raising public awareness of water scarcity, especially with the raise of the internet era in recent years.

View south of hydraulic hammer in boilermakers shop (probably the ...

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

View south of hydraulic hammer in boilermakers shop (probably the oldest piece of equipment in the yard, originally powered by steam) nameplate: United Engineers and FDRY. Co. Pittsburgh, Pa, USA Davy Brothers LTD. Patents - Aug 1, 1905, Feb, 1901, Sept 8, 1908 - 10000 lbs. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

Mass Transfer via Low-Velocity Rebound in a Microgravity Environment

NASA Astrophysics Data System (ADS)

Jarmak, S. G.; Colwell, J. E.; Brisset, J.; Dove, A.; Brown, A. Q.

2017-12-01

Observations of low-velocity collisions (< 1 m/s) between μm to cm-size particles in a microgravity environment are crucial to an understanding of the surface properties of small, airless bodies as well as the processes that lead to their formation. The COLLIDE (Collisions Into Dust Experiment) and PRIME (Physics of Regolith Impacts in Microgravity Experiment) programs created impacts into simulated planetary regolith with cm-scale impactors to observe ejecta production and coefficients of restitution in microgravity. These experiments were carried out on orbit (COLLIDE, COLLIDE-2), in suborbital space (COLLIDE-3), and on parabolic airplane flights (PRIME) under vacuum. Some impacts at speeds less than 40 cm/s resulted in mass transfer from the target regolith onto the impactor. To study these mass-transfer collisions in more detail without the cost or time requirements of spaceflight or parabolic flights, we developed an experimental apparatus in a laboratory drop tower (free-fall time 0.75 s) and performed experiments at standard pressure. The impactor is suspended from a spring and remains in contact with the bed of regolith until free-fall allows the spring to retract and pull the impactor upwards. This method allowed us to simulate the rebound portion of a low-velocity collision in a laboratory microgravity environment. We achieved rebound velocities of 10 - 60 cm/s, and we observed mass transfer events with rebound speeds below 40 cm/s. The amount of mass transfer produced was more significant than a monolayer of granular material, but less than the amount observed in the COLLIDE and PRIME experiments. These mass-transfer collisions may play a role in the growth of planetesimals. We will present the results of our laboratory-based studies where we vary impact velocity and target material, and discuss implications for collisional evolution in the protoplanetary disk and planetary rings.

Poroelastic rebound along the Landers 1992 earthquake surface rupture

USGS Publications Warehouse

Peltzer, G.; Rosen, P.; Rogez, F.; Hudnut, K.

1998-01-01

Maps of surface displacement following the 1992 Landers, California, earthquake, generated by interferometric processing of ERS-1 synthetic aperture radar (SAR) images, reveal effects of various postseismic deformation processes along the 1992 surface rupture. The large-scale pattern of the postseismic displacement field includes large lobes, mostly visible on the west side of the fault, comparable in shape with the lobes observed in the coseismic displacement field. This pattern and the steep displacement gradient observed near the Emerson-Camp Rock fault cannot be simply explained by afterslip on deep sections of the 1992 rupture. Models show that horizontal slip occurring on a buried dislocation in a Poisson's material produces a characteristic quadripole pattern in the surface displacement field with several centimeters of vertical motion at distances of 10-20 km from the fault, yet this pattern is not observed in the postseismic interferograms. As previously proposed to explain local strain in the fault step overs [Peltzer et al., 1996b], we argue that poroelastic rebound caused by pore fluid flow may also occur over greater distances from the fault, compensating the vertical ground shift produced by fault afterslip. Such a rebound is explained by the gradual change of the crustal rocks' Poisson's ratio value from undrained (coseismic) to drained (postseismic) conditions as pore pressure gradients produced by the earthquake dissipate. Using the Poisson's ratio values of 0.27 and 0.31 for the drained and undrained crustal rocks, respectively, elastic dislocation models show that the combined contributions of afterslip on deep sections of the fault and poroelastic rebound can account for the range change observed in the SAR data and the horizontal displacement measured at Global Positioning System (GPS) sites along a 60-km-long transect across the Emerson fault [Savage and Svarc, 1997]. Using a detailed surface slip distribution on the Homestead Valley, Kickapoo

Comparison of Amplitudes and Frequencies of Explosive vs. Hammer Seismic Sources for a 1-km Seismic Line in West Texas

NASA Astrophysics Data System (ADS)

Kaip, G.; Harder, S. H.; Karplus, M. S.; Vennemann, A.

2016-12-01

In May 2016, the National Seismic Source Facility (NSSF) located at the University of Texas at El Paso (UTEP) Department of Geological Sciences collected seismic data at the Indio Ranch located 30 km southwest of Van Horn, Texas. Both hammer on an aluminum plate and explosive sources were used. The project objective was to image subsurface structures at the ranch, owned by UTEP. Selecting the appropriate seismic source is important to reach project objectives. We compare seismic sources between explosions and hammer on plate, focusing on amplitude and frequency. The seismic line was 1 km long, trending WSW to ENE, with 200 4.5 Hz geophones at 5m spacing and shot locations at 10m spacing. Clay slurry was used in shot holes to increase shot coupling around booster. Trojan Spartan cast boosters (150g) were used in explosive sources in each shot hole (1 hole per station). The end of line shots had 5 shot holes instead of 1 (750g total). The hammer source utilized a 5.5 kg hammer and an aluminum plate. Five hammer blows were stacked at each location to improve signal-to-noise ratio. Explosive sources yield higher amplitude, but lower frequency content. The explosions exhibit a higher signal-to-noise ratio, allowing us to recognize seismic energy deeper and farther from the source. Hammer sources yield higher frequencies, allowing better resolution at shallower depths but have a lower signal-to-noise ratio and lower amplitudes, even with source stacking. We analyze the details of the shot spectra from the different types of sources. A combination of source types can improve data resolution and amplitude, thereby improving imaging potential. However, cost, logistics, and complexities also have a large influence on source selection.

Experience in Grid Site Testing for ATLAS, CMS and LHCb with HammerCloud

NASA Astrophysics Data System (ADS)

Elmsheuser, Johannes; Medrano Llamas, Ramón; Legger, Federica; Sciabà, Andrea; Sciacca, Gianfranco; Úbeda García, Mario; van der Ster, Daniel

2012-12-01

Frequent validation and stress testing of the network, storage and CPU resources of a grid site is essential to achieve high performance and reliability. HammerCloud was previously introduced with the goals of enabling VO- and site-administrators to run such tests in an automated or on-demand manner. The ATLAS, CMS and LHCb experiments have all developed VO plugins for the service and have successfully integrated it into their grid operations infrastructures. This work will present the experience in running HammerCloud at full scale for more than 3 years and present solutions to the scalability issues faced by the service. First, we will show the particular challenges faced when integrating with CMS and LHCb offline computing, including customized dashboards to show site validation reports for the VOs and a new API to tightly integrate with the LHCbDIRAC Resource Status System. Next, a study of the automatic site exclusion component used by ATLAS will be presented along with results for tuning the exclusion policies. A study of the historical test results for ATLAS, CMS and LHCb will be presented, including comparisons between the experiments’ grid availabilities and a search for site-based or temporal failure correlations. Finally, we will look to future plans that will allow users to gain new insights into the test results; these include developments to allow increased testing concurrency, increased scale in the number of metrics recorded per test job (up to hundreds), and increased scale in the historical job information (up to many millions of jobs per VO).

Postinhibitory rebound neurons and networks are disrupted in retrovirus-induced spongiform neurodegeneration

PubMed Central

Li, Ying; Davey, Robert A.; Lynch, William P.

2014-01-01

Certain retroviruses induce progressive spongiform motor neuron disease with features resembling prion diseases and amyotrophic lateral sclerosis. With the neurovirulent murine leukemia virus (MLV) FrCasE, Env protein expression within glia leads to postsynaptic vacuolation, cellular effacement, and neuronal loss in the absence of neuroinflammation. To understand the physiological changes associated with MLV-induced spongiosis, and its neuronal specificity, we employed patch-clamp recordings and voltage-sensitive dye imaging in brain slices of the mouse inferior colliculus (IC), a midbrain nucleus that undergoes extensive spongiosis. IC neurons characterized by postinhibitory rebound firing (PIR) were selectively affected in FrCasE-infected mice. Coincident with Env expression in microglia and in glia characterized by NG2 proteoglycan expression (NG2 cells), rebound neurons (RNs) lost PIR, became hyperexcitable, and were reduced in number. PIR loss and hyperexcitability were reversed by raising internal calcium buffer concentrations in RNs. PIR-initiated rhythmic circuits were disrupted, and spontaneous synchronized bursting and prolonged depolarizations were widespread. Other IC neuron cell types and circuits within the same degenerative environment were unaffected. Antagonists of NMDA and/or AMPA receptors reduced burst firing in the IC but did not affect prolonged depolarizations. Antagonists of L-type calcium channels abolished both bursts and slow depolarizations. IC infection by the nonneurovirulent isogenic virus Friend 57E (Fr57E), whose Env protein is structurally similar to FrCasE, showed no RN hyperactivity or cell loss; however, PIR latency increased. These findings suggest that spongiform neurodegeneration arises from the unique excitability of RNs, their local regulation by glia, and the disruption of this relationship by glial expression of abnormal protein. PMID:25252336

Impact of industrial hammer mill rotor speed on extraction efficiency and quality of extra virgin olive oil.

PubMed

Polari, Juan J; Garcí-Aguirre, David; Olmo-García, Lucía; Carrasco-Pancorbo, Alegría; Wang, Selina C

2018-03-01

Crushing is a key step during olive oil extraction. Among commercial crushers, the hammer mill is the most widely used due to its robustness and high throughput. In the present work, the impact of hammer mill rotor speed on extraction yield and overall quality of super-high-density Arbosana olive oils were assessed in an industrial facility. Our results show that increasing the rotor speed from 2400rpm to 3600rpm led to a rise in oil yield of 1.2%, while conserving quality parameters. Sensory analysis showed more pungency with increased rotation speed, while others attributes were unaffected. Volatile compounds showed little variation with the differences in crusher speed; however, total phenols content, two relevant secoiridoids, and triterpenoids levels increased with rotor speed. Hammer mill rotor speed is a processing variable that can be tuned to increase the extraction efficiency and modulate the chemical composition of extra virgin olive oil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anisotropy in Alpedrete granite cutting (Rift, Grain and Hardway directions) and effect on bush hammered heritage ashlars

NASA Astrophysics Data System (ADS)

Freire-Lista, David Martin; Fort, Rafael

2015-04-01

Many monuments and cities that are part of humanity's heritage have been built with carved granite ashlars. This dimension stone is one of the most used due to its abundance and durability. Traditional quarrymen have used anisotropic planes to cut granite blocks in the quarry for improved cutting performance. These planes are called Rift, Grain and Hardway (R, G, H) according to the ease of cutting. The aim of this study is to determine the response of each of the three orthogonal cutting planes R, G and H to the craft styling with bush hammer, based on their decay. Alpedrete granite was selected for this research, it is a monzogranite quarried in the Sierra de Guadarrana (Spanish Central System) foothills, in the province of Madrid, Spain. It is one of the most representative of Madrid's heritage granites. Alpedrete granite is also used as building stone in other European cities. From an Alpedrete granite bush hammered ashlar, three thin sections were cut parallel to the H plane; these thin sections cut R and G bush hammered planes. Also three thin sections have been cut parallel to the R plane at a distance of 2 mm, 10 mm and 30 mm from the bush hammered surface. All thin sections have been treated with fluorescein. In each of the thin sections a micrograph mosaic was performed covering the entire area (about 10 cm2, 300 photomicrographs) and printed with 120 increases. The length and spacing of inter-, intra- and trans-crystalline microcracks were quantified and measured. Microcracks were subdivided based on affected minerals in each R, G and H planes. Through these observations it was found that Alpedrete Granite R plane (easier to cut) is determined by exfoliation microcracks orientation. That is, R plane is parallel to the exfoliations microcracks, which are intra-crystalline and straight. The cutting of stones in the R plane is due to the coalescence of straight microcracks in the plane. This plane minimizes the effort and cost of subsequent carving so it

Attachment-related strategies during thought suppression: ironic rebounds and vulnerable self-representations.

PubMed

Mikulincer, Mario; Dolev, Tamar; Shaver, Phillip R

2004-12-01

The authors conducted 2 studies of attachment-related variations in thought suppression. Participants were asked, or not asked, to suppress thoughts about a relationship breakup and then to perform a Stroop task under high or low cognitive load. The dependent variables were the rebound, of previously suppressed separation-related thoughts (Study 1) and the accessibility of self-traits (Study 2). Under low cognitive load, avoidant individuals did not show any rebound of separation-related thoughts and activated positive self-representations. Under high cognitive load, avoidant participants failed to suppress thoughts of separation and were more likely to activate negative self-representations. Attachment anxiety was associated with high activation of negative self-representations and unremitting separation-related thoughts. The results are discussed in terms of the hidden vulnerabilities of avoidant individuals. ((c) 2004 APA, all rights reserved).

Naive, captive long-tailed macaques (Macaca fascicularis fascicularis) fail to individually and socially learn pound-hammering, a tool-use behaviour

PubMed Central

Tennie, Claudio

2018-01-01

A subspecies of long-tailed macaques (Macaca fascicularis aurea; Mfa) has been reported to use stone tools and a specific technique to process nuts in Southeast Asia, a behaviour known as ‘pound-hammering’. The aim of this study was to examine the development of pound-hammering in long-tailed macaques: whether this behavioural form can be individually learnt or whether it has to rely on some forms of social learning. Given the absence of Mfa from captivity, long-tailed macaques of a highly related subspecies (Macaca fascicularis fascicularis; Mff) were experimentally tested by providing them with the ecological materials necessary to show pound-hammering. A baseline was first carried out to observe whether pound-hammering would emerge spontaneously without social information. As this was not the case, different degrees of social information, culminating in a full demonstration of the behaviour, were provided. None of the subjects (n = 31) showed pound-hammering in any of the individual or social learning conditions. Although these data do not support the hypothesis that individual learning underlies this behaviour, no evidence was found that (at least) Mff learn pound-hammering socially either. We propose that other—potentially interacting—factors may determine whether this behaviour emerges in the various subspecies of long-tailed macaques, and provide a novel methodology to test the role of social and individual learning in the development of animal tool-use. PMID:29892375

Rebound coagulopathy in patients with snakebite presenting with marked initial coagulopathy.

PubMed

Witham, Willam R; McNeill, Cathy; Patel, Sunny

2015-06-01

An estimated 70% of patients with pit viper snakebites require antivenom to treat serious complications such as coagulopathy. Evidence-based guidance is limited for the appropriate administration of Crotalinae Polyvalent Immune Fab (FabAV) and the duration of laboratory follow-up. The objective of our study was to assess the incidence of marked and recurrent envenomation coagulopathy at our trauma center and identify practice patterns that may prevent serious complications. A retrospective case review was conducted over a 3-year period on patients treated for symptomatic snakebite injury. Case records were reviewed for the inclusion criteria of international normalized ratio (INR) greater than 2.0. The exclusion criterion was limited to patients receiving anticoagulant therapy. In all, 61 patients were identified on retrospective chart review and 3 patients (4.9%) met inclusion criteria. Two of the 3 patients had marked rebound coagulopathy requiring readmission and additional treatment. In our small series, 2 patients presenting after crotaline envenomation with increased INR (>6.0), decreased fibrinogen (<60 mg/dL), and decreased platelet count (<100,000/mL) had recurrent coagulopathy and were asymptomatic, and recurrence was noted only with follow-up laboratory testing. All patients responded positively within a matter of hours to repeat FabAV administration, with resolution of rebound coagulopathy. We recommend periodic monitoring of patients with increased INR, decreased fibrinogen, and decreased platelet count. Patients should be monitored for 10 to 14 days after envenomation to identify asymptomatic rebound coagulopathy. Prompt readministration of FabAV appears to correct the coagulopathy. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Hypothenar hammer syndrome: a case and brief review.

PubMed

Swanson, Keith E; Bartholomew, John R; Paulson, Rolf

2012-04-01

Hypothenar hammer syndrome is an uncommon cause of upper-extremity ischemia that is often overlooked in the absence of a thorough occupational and recreational history. Importantly, it is a reversible cause of hand ischemia that, if missed, can lead to significant morbidity and even amputation. The occupational ramifications and quality of life of those affected can be significant. Its relative rarity, set against the ubiquitous use of the hand as a 'hammer' is noteworthy. Several other causes of hand ischemia can present similarly; therefore, consideration of other etiologies must be thoroughly investigated. Key distinguishing clinical features, in addition to a detailed occupational and recreational history, may include characteristic sparing of the thumb, the absence of a hyperemic phase in 'Raynaud's phenomenon', and a positive Allen's sign. Both non-invasive and invasive diagnostic studies, including bilateral upper-limb segmental pulse volume recordings (PVR), arterial duplex examination, and upper-extremity angiography, are complementary to a thorough history and physical examination. Optimal management strategies are not well defined because of its rarity and resultant lack of quality, evidence-based data. Though most cases can be successfully managed non-operatively, micrographic arterial reconstruction may be limb saving in severe or recalcitrant cases. Newer, experimental strategies including selective sympathetic blockage using botulinum toxin A have been reported in a few recalcitrant cases. The brief case description illustrates the typical presentation and potential treatment strategies employed in a difficult case. A review of relevant literature is also presented.

Subsurface sediment contamination during borehole drilling with an air-actuated down-hole hammer.

PubMed

Malard, Florian; Datry, Thibault; Gibert, Janine

2005-10-01

Drilling methods can severely alter physical, chemical, and biological properties of aquifers, thereby influencing the reliability of water samples collected from groundwater monitoring wells. Because of their fast drilling rate, air-actuated hammers are increasingly used for the installation of groundwater monitoring wells in unconsolidated sediments. However, oil entrained in the air stream to lubricate the hammer-actuating device can contaminate subsurface sediments. Concentrations of total hydrocarbons, heavy metals (Cu, Ni, Cr, Zn, Pb, and Cd), and nutrients (particulate organic carbon, nitrogen, and phosphorus) were measured in continuous sediment cores recovered during the completion of a 26-m deep borehole drilled with a down-hole hammer in glaciofluvial deposits. Total hydrocarbons, Cu, Ni, Cr and particulate organic carbon (POC) were all measured at concentrations far exceeding background levels in most sediment cores. Hydrocarbon concentration averaged 124 +/- 118 mg kg(-1) dry sediment (n = 78 samples) with peaks at depths of 8, 14, and 20 m below the soil surface (maximum concentration: 606 mg kg(-1)). The concentrations of hydrocarbons, Cu, Ni, Cr, and POC were positively correlated and exhibited a highly irregular vertical pattern, that probably reflected variations in air loss within glaciofluvial deposits during drilling. Because the penetration of contaminated air into the formation is unpreventable, the representativeness of groundwater samples collected may be questioned. It is concluded that air percussion drilling has strong limitations for well installation in groundwater quality monitoring surveys.

Vertebrobasilar Dolichoectasia Induced Hydrocephalus: the Water-Hammer Effect

PubMed Central

Zisimopoulou, Vaso; Ntouniadaki, Aikaterini; Aggelidakis, Panagiotis; Siatouni, Anna; Gatzonis, Stylianos; Tavernarakis, Antonios

2015-01-01

Vertebrobasilar dolichoectasia is a clinical entity associated rarely with obstructive hydrocephalus. We present a 48-year old male with a profound dilatation of the ventricular system due to a dolichoectatic basilar artery, as appeared in imaging studies. The patient suffered from longstanding hydrocephalus and presenile dementia. The underlying mechanism for obstructive hydrocephalus due to vertebrobasilar dolichoectasia is considered to be both a water-hammer effect and a direct compression of adjacent structures. We suggest prompt surgical intervention upon diagnosis as a first choice treatment in order to avoid further complications. PMID:26236456

Vertebrobasilar Dolichoectasia Induced Hydrocephalus: the Water-Hammer Effect.

PubMed

Zisimopoulou, Vaso; Ntouniadaki, Aikaterini; Aggelidakis, Panagiotis; Siatouni, Anna; Gatzonis, Stylianos; Tavernarakis, Antonios

2015-04-24

Vertebrobasilar dolichoectasia is a clinical entity associated rarely with obstructive hydrocephalus. We present a 48-year old male with a profound dilatation of the ventricular system due to a dolichoectatic basilar artery, as appeared in imaging studies. The patient suffered from longstanding hydrocephalus and presenile dementia. The underlying mechanism for obstructive hydrocephalus due to vertebrobasilar dolichoectasia is considered to be both a water-hammer effect and a direct compression of adjacent structures. We suggest prompt surgical intervention upon diagnosis as a first choice treatment in order to avoid further complications.

DETAIL VIEW OF INTERIOR SHOWING TWO 3,000POUND STEAM HAMMERS, CA. ...

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

DETAIL VIEW OF INTERIOR SHOWING TWO 3,000-POUND STEAM HAMMERS, CA. 1905, CONVERTED TO COMPRESSED AIR 1985 (MANUFACTURED BY CHAMBERSBURG ENGINEERING COMPANY, CHAMBERSBURG, PENNSYLVANIA), LOCATED ON EITHER SIDE OF CAST-IRON CENTRAL SUPPORT COLUMN. - Cambria Iron Company, Blacksmith Shop, Lower Works, Johnstown, Cambria County, PA

Lock-and-key mechanisms of cerebellar memory recall based on rebound currents.

PubMed

Wetmore, Daniel Z; Mukamel, Eran A; Schnitzer, Mark J

2008-10-01

A basic question for theories of learning and memory is whether neuronal plasticity suffices to guide proper memory recall. Alternatively, information processing that is additional to readout of stored memories might occur during recall. We formulate a "lock-and-key" hypothesis regarding cerebellum-dependent motor memory in which successful learning shapes neural activity to match a temporal filter that prevents expression of stored but inappropriate motor responses. Thus, neuronal plasticity by itself is necessary but not sufficient to modify motor behavior. We explored this idea through computational studies of two cerebellar behaviors and examined whether deep cerebellar and vestibular nuclei neurons can filter signals from Purkinje cells that would otherwise drive inappropriate motor responses. In eyeblink conditioning, reflex acquisition requires the conditioned stimulus (CS) to precede the unconditioned stimulus (US) by >100 ms. In our biophysical models of cerebellar nuclei neurons this requirement arises through the phenomenon of postinhibitory rebound depolarization and matches longstanding behavioral data on conditioned reflex timing and reliability. Although CS-US intervals<100 ms may induce Purkinje cell plasticity, cerebellar nuclei neurons drive conditioned responses only if the CS-US training interval was >100 ms. This bound reflects the minimum time for deinactivation of rebound currents such as T-type Ca2+. In vestibulo-ocular reflex adaptation, hyperpolarization-activated currents in vestibular nuclei neurons may underlie analogous dependence of adaptation magnitude on the timing of visual and vestibular stimuli. Thus, the proposed lock-and-key mechanisms link channel kinetics to recall performance and yield specific predictions of how perturbations to rebound depolarization affect motor expression.

The effect of cryogenic grinding and hammer milling on the flavour quality of ground pepper (Piper nigrum L.).

PubMed

Liu, Hong; Zeng, Fankui; Wang, Qinghuang; Ou, Shiyi; Tan, Lehe; Gu, Fenglin

2013-12-15

In this study, we compared the effects of cryogenic grinding and hammer milling on the flavour attributes of black, white, and green pepper. The flavour attributes were analysed using headspace solid-phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS), sensory evaluation and electronic nose (e-nose) analysis. Cryogenic grinding resulted in minimal damage to the colour, flavour, and sensory attributes of the spices. Cryogenic grinding was also better than hammer milling at preserving the main potent aroma constituents, but the concentrations of the main aroma constituents were dramatically reduced after storing the samples at 4 °C for 6 months. Pattern matching performed by the e-nose further supported our sensory and instrumental findings. Overall, cryogenic grinding was superior to hammer milling for preserving the sensory properties and flavour attributes of pepper without significantly affecting its quality. However, we found that the flavour quality of ground pepper was reduced during storage. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rebound spiking in layer II medial entorhinal cortex stellate cells: Possible mechanism of grid cell function

PubMed Central

Shay, Christopher F.; Ferrante, Michele; Chapman, G. William; Hasselmo, Michael E.

2015-01-01

Rebound spiking properties of medial entorhinal cortex (mEC) stellate cells induced by inhibition may underlie their functional properties in awake behaving rats, including the temporal phase separation of distinct grid cells and differences in grid cell firing properties. We investigated rebound spiking properties using whole cell patch recording in entorhinal slices, holding cells near spiking threshold and delivering sinusoidal inputs, superimposed with realistic inhibitory synaptic inputs to test the capacity of cells to selectively respond to specific phases of inhibitory input. Stellate cells showed a specific phase range of hyperpolarizing inputs that elicited spiking, but non-stellate cells did not show phase specificity. In both cell types, the phase range of spiking output occurred between the peak and subsequent descending zero crossing of the sinusoid. The phases of inhibitory inputs that induced spikes shifted earlier as the baseline sinusoid frequency increased, while spiking output shifted to later phases. Increases in magnitude of the inhibitory inputs shifted the spiking output to earlier phases. Pharmacological blockade of h-current abolished the phase selectivity of hyperpolarizing inputs eliciting spikes. A network computational model using cells possessing similar rebound properties as found in vitro produces spatially periodic firing properties resembling grid cell firing when a simulated animal moves along a linear track. These results suggest that the ability of mEC stellate cells to fire rebound spikes in response to a specific range of phases of inhibition could support complex attractor dynamics that provide completion and separation to maintain spiking activity of specific grid cell populations. PMID:26385258

Measurement and Interpretation of Crustal Deformation Rates Associated with Postglacial Rebound

NASA Technical Reports Server (NTRS)

Davis, James L.

1998-01-01

This project involves obtaining GPS measurements in Scandinavia, and using the measurements to estimate the viscosity profile of the Earth's mantle and to correct tide-gauge measurements for the rebound effect. Many aspects of this project have been reported in the literature (see Section III). In Section II, we report on the primary geodetic results from this project.

Numerical investigation of soil plugging effect inside sleeve of cast-in-place piles driven by vibratory hammers in clays.

PubMed

Xiao, Yong Jie; Chen, Fu Quan; Dong, Yi Zhi

2016-01-01

During driving sleeve of cast-in-place piles by vibratory hammers, soils were squeezed into sleeve and then soil plugging was formed. The physic-mechanical properties of the soil plug have direct influence on the load transmission between the sleeve wall and soil plug. Nevertheless, the researches on this issue are insufficient. In this study, finite element and infinite element coupling model was introduced, through the commercial code ABAQUS, to simulate the full penetration process of the sleeve driven from the ground surface to the desired depth by applying vibratory hammers. The research results indicated that the cyclic shearing action decreases both in soil shear strength and in granular cementation force when the sleeve is driven by vibratory hammers, which leads to a partially plugged mode of the soil plug inside the sleeve. Accordingly, the penetration resistance of sleeve driven by vibratory hammers is the smallest compared to those by other installation methods. When driving the sleeve, the annular soil arches forming in the soil plug at sleeve end induce a significant rise in the internal shaft resistance. Moreover, the influence of vibration frequencies, sleeve diameters, and soil layer properties on the soil plug was investigated in detail, and at the same time improved formulas were brought forward to describe the soil plug resistance inside vibratory driven sleeve.

Psi Chi/APA Edwin B. Newman Graduate Research Award: Joseph H. Hammer

ERIC Educational Resources Information Center

American Psychologist, 2009

2009-01-01

Joseph H. Hammer, recipient of the Psi Chi/APA Edwin B. Newman Graduate Research Award, is cited for an outstanding research paper whose findings provide important evidence regarding the promise of a male-sensitive approach to mental health marketing and empirically support the inclusion of theory-driven enhancements in group-targeted mental…

Comparison of Electrostatic Fins with Piezoelectric Impact Hammer Techniques to Extend Impulse Calibration Range of a Torsional Thrust Stand (Preprint)

DTIC Science & Technology

2011-03-23

prac- tical max impulse to 1mNs. The newly developed Piezo - electric Impact Hammer (PIH) calibration system over- comes geometric limits of ESC...the fins to behave as part of an LRC circuit which results in voltage oscillations. By adding a resistor in series between the pulse generator and...series resistor as well as the effects of no loading on the pulse generator. III. PIEZOELECTRIC IMPACT HAMMER SYSTEM The second calibration method tested

Study on the Effect of the Impact Location and the Type of Hammer Tip on the Frequency Response Function (FRF) in Experimental Modal Analysis of Rectangular Plates

NASA Astrophysics Data System (ADS)

Mali, K. D.; Singru, P. M.

2018-03-01

In this work effect of the impact location and the type of hammer tip on the frequency response function (FRF) is studied. Experimental modal analysis of rectangular plates is carried out for this purpose by using impact hammer, accelerometer and fast Fourier transform (FFT) analyzer. It is observed that the impulse hammer hit location has, no effect on the eigenfrequency, yet a difference in amplitude of the eigenfrequencies is obtained. The effect of the hammer tip on the pulse and the force spectrum is studied for three types of tips metal, plastic and rubber. A solid rectangular plate was excited by using these tips one by one in three different tests. It is observed that for present experimental set up plastic tip excites the useful frequency range.

Underwater Concrete Inspection Equipment

DTIC Science & Technology

1991-04-01

nondestructive testing of con- crete waterfront structures. One instrument is a magnetic rebar locator that locates rebar in concrete structures and measures the...amount of con- crete cover over the rebar . Another instrument is a rebound hammer that measures the surface hardness of the concrete . The third...development of three specialized instruments for the underwater nondestructive testing or concrete waterfront structures. One instrument is a magnetic rebar

Delay-induced rebounds in CO2 emissions and critical time-scales to meet global warming targets

NASA Astrophysics Data System (ADS)

Manoli, Gabriele; Katul, Gabriel G.; Marani, Marco

2016-12-01

While climate science debates are focused on the attainment of peak anthropogenic CO2 emissions and policy tools to reduce peak temperatures, the human-energy-climate system can hold "rebound" surprises beyond this peak. Following the second industrial revolution, global per capita CO2 emissions (cc) experienced a punctuated growth of about 100% every 60 years, mainly attributable to technological development and its global spread. A model of the human-energy-climate system capable of reproducing past punctuated dynamics shows that rebounds in global CO2 emissions emerge due to delays intrinsic to the diffusion of innovations. Such intrinsic delays in the adoption and spread of low-carbon emitting technologies, together with projected population growth, upset the warming target set by the Paris Agreement. To avoid rebounds and their negative climate effects, model calculations show that the diffusion of climate-friendly technologies must occur with lags one-order of magnitude shorter (i.e., ˜6 years) than the characteristic timescale of past punctuated growth in cc. Radically new strategies to globally implement the technological advances at unprecedented rates are needed if the current emission goals are to be achieved.

Auto Indexer Auto-Indexer for Percussive Hammers: Vane Motor Dynamometer Testing

DOE Data Explorer

Su, Jiann

2012-01-01

Objectives Options associated with geothermal drilling operations are generally limited by factors such as formation temperature and rock strength. The objective of the research is to expand the "tool box" available to the geothermal driller by furthering the development of a high-temperature drilling motor that can be used in directional drilling applications for drilling high temperature geothermal formations. The motor is specifically designed to operate in conjunction with a pneumatic down-the-hole-hammer. It provides a more compact design compared to traditional drilling motors such as PDMs (positive displacement motors). The packaging can help to enhance directional drilling capabilities. It uses no elastomeric components, which enables it to operate in higher temperatures ( >250 °F). Current work on the motor has shown that is a capable of operating under pneumatic power with a down-the-hole-hammer. Further development work will include continued testing and refining motor components and evaluating motor capabilities. Targets/Milestones Complete testing current motor - 12/31/2010 Make final material and design decisions - 01/31/2011 Build and test final prototype - 04/31/2011 Final demonstration - 07/31/2011 Impacts The development of the motor will help to achieve program technical objectives by improving well construction capabilities. This includes enabling high-temperature drilling as well as enhancing directional drilling. A key component in the auto indexer is the drive motor. It is an air-driven vane motor that converts the energy stored in the compressed air to mechanical energy. The motor is attached to hammer-like components which impart an impulsive load onto the drive shaft. The impulsive force on the drive shaft in turn creates an indexing action. A controlled test was performed to characterize the performance of the the vane motor for a given pressure. The Sandia dynamometer test station was used to determine the performance of the motor for a

Theoretical analysis and design of hydro-hammer with a jet actuator: An engineering application to improve the penetration rate of directional well drilling in hard rock formations.

PubMed

He, Jiang-Fu; Liang, Yun-Pei; Li, Li-Jia; Luo, Yong-Jiang

2018-01-01

Rapid horizontal directional well drilling in hard or fractured formations requires efficient drilling technology. The penetration rate of conventional hard rock drilling technology in horizontal directional well excavations is relatively low, resulting in multiple overgrinding of drill cuttings in bottom boreholes. Conventional drilling techniques with reamer or diamond drill bit face difficulties due to the long construction periods, low penetration rates, and high engineering costs in the directional well drilling of hard rock. To improve the impact energy and penetration rate of directional well drilling in hard formations, a new drilling system with a percussive and rotary drilling technology has been proposed, and a hydro-hammer with a jet actuator has also been theoretically designed on the basis of the impulse hydro-turbine pressure model. In addition, the performance parameters of the hydro-hammer with a jet actuator have been numerically and experimentally analyzed, and the influence of impact stroke and pumped flow rate on the motion velocity and impact energy of the hydro-hammer has been obtained. Moreover, the designed hydro-hammer with a jet actuator has been applied to hard rock drilling in a trenchless drilling program. The motion velocity of the hydro-hammer ranges from 1.2 m/s to 3.19 m/s with diverse flow rates and impact strokes, and the motion frequency ranges from 10 Hz to 22 Hz. Moreover, the maximum impact energy of the hydro-hammer is 407 J, and the pumped flow rate is 2.3 m3/min. Thus, the average penetration rate of the optimized hydro-hammer improves by over 30% compared to conventional directional drilling in hard rock formations.

Theoretical analysis and design of hydro-hammer with a jet actuator: An engineering application to improve the penetration rate of directional well drilling in hard rock formations

PubMed Central

He, Jiang-fu; Li, Li-jia; Luo, Yong-jiang

2018-01-01

Rapid horizontal directional well drilling in hard or fractured formations requires efficient drilling technology. The penetration rate of conventional hard rock drilling technology in horizontal directional well excavations is relatively low, resulting in multiple overgrinding of drill cuttings in bottom boreholes. Conventional drilling techniques with reamer or diamond drill bit face difficulties due to the long construction periods, low penetration rates, and high engineering costs in the directional well drilling of hard rock. To improve the impact energy and penetration rate of directional well drilling in hard formations, a new drilling system with a percussive and rotary drilling technology has been proposed, and a hydro-hammer with a jet actuator has also been theoretically designed on the basis of the impulse hydro-turbine pressure model. In addition, the performance parameters of the hydro-hammer with a jet actuator have been numerically and experimentally analyzed, and the influence of impact stroke and pumped flow rate on the motion velocity and impact energy of the hydro-hammer has been obtained. Moreover, the designed hydro-hammer with a jet actuator has been applied to hard rock drilling in a trenchless drilling program. The motion velocity of the hydro-hammer ranges from 1.2 m/s to 3.19 m/s with diverse flow rates and impact strokes, and the motion frequency ranges from 10 Hz to 22 Hz. Moreover, the maximum impact energy of the hydro-hammer is 407 J, and the pumped flow rate is 2.3 m3/min. Thus, the average penetration rate of the optimized hydro-hammer improves by over 30% compared to conventional directional drilling in hard rock formations. PMID:29768421

Modification of General Research Corporation (GRC) Dynatup 8200 Drop Tower Rebounding Brake System

DTIC Science & Technology

2016-08-01

Having 1.5-inch stroke low-volume actuators, retracted t t Approved for public release; distribution is unlimited. 3 multiple impacts from...rebound period at 1000 fps. Fig. 5 New upgraded 3-inch pneumatic cylinders 3.0-inch stroke high-volume actuators Retracted Position Extended

CFD simulation of reverse water-hammer induced by collapse of draft-tube cavity in a model pump-turbine during runaway process

NASA Astrophysics Data System (ADS)

Zhang, Xiaoxi; Cheng, Yongguang; Xia, Linsheng; Yang, Jiandong

2016-11-01

This paper reports the preliminary progress in the CFD simulation of the reverse water-hammer induced by the collapse of a draft-tube cavity in a model pump-turbine during the runaway process. Firstly, the Fluent customized 1D-3D coupling model for hydraulic transients and the Schnerr & Sauer cavitation model for cavity development are introduced. Then, the methods are validated by simulating the benchmark reverse water-hammer in a long pipe caused by a valve instant closure. The simulated head history at the valve agrees well with the measured data in literature. After that, the more complicated reverse water-hammer in the draft-tube of a runaway model pump-turbine, which is installed in a model pumped-storage power plant, is simulated. The dynamic processes of a vapor cavity, from generation, expansion, shrink to collapse, are shown. After the cavity collapsed, a sudden increase of pressure can be evidently observed. The process is featured by a locally expending and collapsing vapor cavity that is around the runner cone, which is different from the conventional recognition of violent water- column separation. This work reveals the possibility for simulating the reverse water-hammer phenomenon in turbines by 3D CFD.

Influence of a mini-trampoline rebound exercise program on insulin resistance, lipid profile and central obesity in individuals with type 2 diabetes.

PubMed

Nuhu, Jibril M; Maharaj, Sonill S

2018-04-01

Exercises are important as an adjuvant for managing diabetes but due to fatigue and time constraints, individuals with diabetes may not engage in them. Jumping on a mini-trampoline referred to as rebound exercise is an aerobic activity used for exercise training benefits but only little research is available on its effects in diabetes. The purpose of this study was to determine the effect of mini-trampoline rebound exercise on insulin resistance, lipid profile and central obesity in type 2 diabetics. Sixty non-insulin dependent type 2 diabetics (median age: 39.0 years, median body mass index: 25.2 kg/m2) recruited using convenience sampling were randomized to a rebound exercise group (N.=30) or a control group (N.=30). The control group read health magazines or watched television while the rebound exercise group jumped on a mini-trampoline at moderate intensity for 30 minutes three times per week for 12 weeks. Postrebound exercise, significant improvements in insulin resistance, lipid profile and waist circumference were noted when compared to the control (P<0.05). The values for high density lipoprotein cholesterol increased with low density lipoprotein cholesterol, triglycerides, insulin resistance decreasing significantly from baseline (P<0.05). The findings suggest that mini-trampoline rebound exercise is beneficial for individuals with type 2 diabetes and can serve as a useful exercise approach in the management of cardiovascular risk in diabetes.

Elastic rebound following the Kocaeli earthquake, Turkey, recorded using synthetic aperture radar interferometry

USGS Publications Warehouse

Mayer, Larry; Lu, Zhong

2001-01-01

A basic model incorporating satellite synthetic aperture radar (SAR) interferometry of the fault rupture zone that formed during the Kocaeli earthquake of August 17, 1999, documents the elastic rebound that resulted from the concomitant elastic strain release along the North Anatolian fault. For pure strike-slip faults, the elastic rebound function derived from SAR interferometry is directly invertible from the distribution of elastic strain on the fault at criticality, just before the critical shear stress was exceeded and the fault ruptured. The Kocaeli earthquake, which was accompanied by as much as ∼5 m of surface displacement, distributed strain ∼110 km around the fault prior to faulting, although most of it was concentrated in a narrower and asymmetric 10-km-wide zone on either side of the fault. The use of SAR interferometry to document the distribution of elastic strain at the critical condition for faulting is clearly a valuable tool, both for scientific investigation and for the effective management of earthquake hazard.

An Investigation of Tic Suppression and the Rebound Effect in Tourette's Disorder

ERIC Educational Resources Information Center

Meidinger, Amy L.; Miltenberger, Raymond G.; Himle, Michael; Omvig, Matthew; Trainor, Casey; Crosby, Ross

2005-01-01

Many patients, parents of children with Tourettes disorder, and professionals have suggested that following a period of suppression, tics will rebound to a rate that will exceed the average rate of occurrence. At present, there are no empirical data to support or refute such an effect. This experiment utilized an A-B-A design with replication to…

The Effect of Venue and Wind on the Distance of a Hammer Throw

ERIC Educational Resources Information Center

Hunter, Iain

2005-01-01

In track and field, gravity and air resistance act on the hammer after it has been released. Both of these forces depend on altitude and latitude. In addition, air resistance also depends on wind, temperature, humidity, and barometric pressure. Often, air resistance and varying gravity throughout the earth are not considered when throwing…

Intraocular pressure measurement over soft contact lens by rebound tonometer: a comparative study

PubMed Central

Nacaroglu, Senay Asik; Un, Emine Seker; Ersoz, Mehmet Giray; Tasci, Yelda

2015-01-01

AIM To evaluate the intraocular pressure (IOP) measurements by Icare rebound tonometer over a contact lens in comparison with Goldmann applanation tonometry (GAT). METHODS Fifty patients using contact lens were included in this study. One of the eyes of the patients was selected randomly and their IOP were measured by rebound tonometer with and without contact lens (RTCL, RT respectively) and by GAT, as well as their central corneal thickness (CCT) by optical pachymeter. The results of both methods were compared by correlation analysis, general linear method repeated measure and Bland-Altman analysis. RESULTS Mean IOP values measured by RTCL, RT and GAT were 15.68±3.7, 14.50±3.4 and 14.16±2.8 (P<0.001), respectively. Mean IOP by RTCL was significantly higher than the measurements implemented by RT and GAT (P<0.001), while there was no difference between the measurements by GAT and RT (P=0.629). There was a good level of positive correlation between GAT and RTCL as well as RT (r=0.786 P<0.001, r=0.833 P<0.001, respectively). We have observed that CCT increase did not show any correlation with the differences of the measurements between RTCL and RT (P=0.329), RTCL and GAT (P=0.07) as well as RT and GAT (P=0.189) in linear regression model. CONCLUSION The average of the measurements over contact lens by rebound tonometer was found to be higher than what was measured by GAT. Although this difference is statistically significant, it may be clinically negligible in the normal population. PMID:26086004

Research on the water hammer protection of the long distance water supply project with the combined action of the air vessel and over-pressure relief valve

NASA Astrophysics Data System (ADS)

Li, D. D.; Jiang, J.; Zhao, Z.; Yi, W. S.; Lan, G.

2013-12-01

We take a concrete pumping station as an example in this paper. Through the calculation of water hammer protection with a specific pumping station water supply project, and the analysis of the principle, mathematical models and boundary conditions of air vessel and over-pressure relief valve we show that the air vessel can protect the water conveyance system and reduce the transient pressure damage due to various causes. Over-pressure relief valve can effectively reduce the water hammer because the water column re-bridge suddenly stops the pump and prevents pipeline burst. The paper indicates that the combination set of air vessel and over-pressure relief valve can greatly reduce the quantity of the air valve and can eliminate the water hammer phenomenon in the pipeline system due to the vaporization and water column separation and re-bridge. The conclusion could provide a reference for the water hammer protection of long-distance water supply system.

REBOUND-ing Off Asteroids: An N-body Particle Model for Ejecta Dynamics on Small Bodies

NASA Astrophysics Data System (ADS)

Larson, Jennifer; Sarid, Gal

2017-10-01

Here we describe our numerical approach to model the evolution of ejecta clouds. Modeling with an N-body particle method enables us to study the micro-dynamics while varying the particle size distribution. A hydrodynamic approach loses many of the fine particle-particle interactions included in the N-body particle approach (Artemieva 2008).We use REBOUND, an N-body integration package (Rein et al. 2012) developed to model various dynamical systems (planetary orbits, ring systems, etc.) with high resolution calculations at a lower performance cost than other N-body integrators (Rein & Tamayo 2017). It offers both symplectic (WHFast) and non-symplectic (IAS15) methods (Rein & Spiegel 2014, Rein & Tamayo 2015). We primarily use the IAS15 integrator due to its robustness and accuracy with short interaction distances and non-conservative forces. We implemented a wrapper (developed in Python) to handle changes in time step and integrator at different stages of ejecta particle evolution.To set up the system, each particle is given a velocity away from the target body’s surface at a given angle within a defined ejecta cone. We study the ejecta cloud evolution beginning immediately after an impact rather than the actual impact itself. This model considers effects such as varying particle size distribution, radiation pressure, perturbations from a binary component, particle-particle collisions and non-axisymmetric gravity of the target body. Restrictions on the boundaries of the target body’s surface define the physical shape and help count the number of particles that land on the target body. Later, we will build the central body from individual particles to allow for a wider variety of target body shapes and topographies.With our particle modeling approach, individual particle trajectories are tracked and predicted on short, medium and long timescales. Our approach will be applied to modeling of the ejecta cloud produced during the Double Asteroid Redirection Test

[Adam hammer (1818 - 1878) - remarks on a forgotten pioneer of ether anaesthesia in obstetrics].

PubMed

Goerig, M; Streckfuss, W

2004-05-01

Adam Hammer, born in 1818, and working as a doctor for the poor since 1847 in Mannheim, was the first person in the German speaking world to use ether for pain relief during labor on February 18th 1847. He took part in the abortive April 1848 Revolution in Mannheim - a pinnacle of German liberalism and later of political radicalism, which attented to abolish the Monarchy and introduce a democratic Republic. After the revolution was put down, Hammer emigrated to the United States and settled down in St. Louis, Missouri. Remaining politically active, he joined the Republican Party, founded in 1854 and served as a military surgeon in the Union Army during the American Civil War. Even before the war, he was engaged in efforts to improve the level of medical training in America and was involved with the foundation of High Schools which offered training courses along the lines of German universities. His ideas and innovations were not introduced immediately, but had a significant impact on medical training methology later on in the US. During a visit in Europe in 1876, he was the first to diagnose a coronary thombosis as the cause of a heart attack on a live patient. The diagnosis was later confirmed by post-morten autopsy on the patient. In 1877 he returned to Germany and died one year later. The biography of Adam Hammer mirrows that of many other German-Americans whose emigration proved to be a gain for America but a loss for Germany. This story was destinated to be repeated in terrible circumstances some decades later.

Self-reported alcohol abuse in HIV-HCV co-infected patients: a better predictor of HIV virological rebound than physician's perceptions (HEPAVIH ARNS CO13 cohort).

PubMed

Marcellin, Fabienne; Lions, Caroline; Winnock, Maria; Salmon, Dominique; Durant, Jacques; Spire, Bruno; Mora, Marion; Loko, Marc-Arthur; Dabis, François; Dominguez, Stéphanie; Roux, Perrine; Carrieri, Maria Patrizia

2013-07-01

Studying alcohol abuse impact, as measured by physicians' perceptions and patients' self-reports, on HIV virological rebound among patients chronically co-infected with HIV and hepatitis C virus (HCV). Cohort study. Seventeen French hospitals. Five hundred and twelve patients receiving antiretroviral therapy (ART) with an undetectable initial HIV viral load and at least two viral load measures during follow-up. Medical records and self-administered questionnaires. HIV virological rebound defined as HIV viral load above the limit of detection of the given hospital's laboratory test. Alcohol abuse defined as reporting to have drunk regularly at least 4 (for men) or 3 (for women) alcohol units per day during the previous 6 months. Correlates of time to HIV virological rebound identified using Cox proportional hazards models. At enrolment, 9% of patients reported alcohol abuse. Physicians considered 14.8% of all participants as alcohol abusers. Self-reported alcohol abuse was associated independently with HIV virological rebound [hazard ratio (95% confidence interval): 2.04 (1.13-3.67); P = 0.02], after adjustment for CD4 count, time since ART initiation and hospital HIV caseload. No significant relationship was observed between physician-reported alcohol abuse and virological rebound (P = 0.87). In France, the assessment of alcohol abuse in patients co-infected with HIV and hepatitis C virus should be based on patients' self-reports, rather than physicians' perceptions. Baseline screening of self-reported alcohol abuse may help identify co-infected patients at risk of subsequent HIV virological rebound. © 2013 Society for the Study of Addiction.

Habitat for Humanity Project Hammers Home the Importance of Volunteerism | Frederick National Laboratory for Cancer Research

Cancer.gov

BRUNSWICK, Md. -- The staccato sounds of hammers and nail guns replaced the typical morning silence of a recent sunny Saturday in Brunswick, Md., where Frederick National Laboratory volunteers, their guests, and staff from Habitat for Humanity of Fre

[REBOUND EFFECT OF INTERVENTION PROGRAMS TO REDUCE OVERWEIGHT AND OBESITY IN CHILDREN AND ADOLESCENTS; SYSTEMATIC REVIEW].

PubMed

Aguilar Cordero, María José; Ortegón Piñero, Alberto; Baena García, Laura; Noack Segovia, Jessica Pamela; Levet Hernández, María Cristina; Sánchez López, Antonio Manuel

2015-12-01

studies show that overweight and obesity are the result of a complex interaction between genetic and environmental factors that begins prenatally. In evidence of this relationship the potential impact of prenatal nutrition experience in the development of the endocrine and neuroendocrine systems that regulate energy balance, with special emphasis on leptin, an adipocytederived hormone. Different authors relate the risk of obesity with rapid weight gain in the first years of life. Breastfeeding children have a lower degree of abdominal adiposity and, therefore, lower waist circumference. Similarly, it has been associated with exclusively breastfeeding with a slower weight gain rate of about 20 %. In the study of obesity, a rebound effect is considered when the child recovers its initial weight a year after finishing the procedure. This problem is common, therefore family intervention is essential in order to achieve the child's motivation to lead a healthy life. For this review we have selected studies to evaluate interventions of medium and long term in childhood obesity, ensuring adherence to treatment and the rebound effect, once the intervention ended. to review studies examining the rebound effect and adherence to weight loss treatments for children and adolescents with overweight and obesity. the systematic review was prepared following the PRISMA guidelines. Are selected 19 studies related to the proposed issue. several authors have established the beneficial short and long term effects of interventions that combine diet and physical activity among obese children. These results show the importance of multidisciplinary treatment programs for childhood obesity, emphasizing its encouraging longterm effects. there are studies were the rebound effect in short duration programs is evident. During interventions it is significantly reduced BMI, but then increased quickly to reach even higher levels initial weight. The most effective type of actions tend to be those

Core groups, antimicrobial resistance and rebound in gonorrhoea in North America.

PubMed

Chan, Christina H; McCabe, Caitlin J; Fisman, David N

2012-04-01

Genital tract infections caused by Neisseria gonorrhoeae are a major cause of sexually transmitted disease worldwide. Surveillance data suggest that incidence has increased in recent years after initially falling in the face of intensified control efforts. The authors sought to evaluate the potential contribution of antimicrobial resistance to such rebound and to identify optimal treatment strategies in the face of resistance using a mathematical model of gonorrhoea. The authors built risk-structured 'susceptible-infectious-susceptible' models with and without the possibility of antibiotic resistance and used these models as a platform for the evaluation of competing plausible treatment strategies, including changing antimicrobial choice when resistance prevalence surpassed fixed thresholds, random assignment of treatment and use of combination antimicrobial therapy. Absent antimicrobial resistance, strategies that focus on treatment of highest risk individuals (the so-called core group) result in collapse of disease transmission. When antimicrobial resistance exists, a focus on the core group causes rebound in incidence, with maximal dissemination of antibiotic resistance. Random assignment of antimicrobial treatment class outperformed the use of fixed resistance thresholds with respect to sustained reduction in gonorrhoea prevalence. Gonorrhoea control is achievable only when core groups are treated, but treatment of core groups maximises dissemination of antimicrobial-resistant strains. This paradox poses a great dilemma to the control and prevention of gonorrhoea and underlines the need for gonococcal vaccines.

Genome sequence of the thermophile Bacillus coagulans Hammer, the type strain of the species.

PubMed

Su, Fei; Tao, Fei; Tang, Hongzhi; Xu, Ping

2012-11-01

Here we announce a 3.0-Mb assembly of the Bacillus coagulans Hammer strain, which is the type strain of the species within the genus Bacillus. Genomic analyses based on the sequence may provide insights into the phylogeny of the species and help to elucidate characteristics of the poorly studied strains of Bacillus coagulans.

Rebound macular edema following oral acetazolamide therapy for juvenile X-linked retinoschisis in an Italian family.

PubMed

Galantuomo, Maria Silvana; Fossarello, Maurizio; Cuccu, Alberto; Farci, Roberta; Preising, Markus N; Lorenz, Birgit; Napoli, Pietro Emanuele

2016-01-01

Juvenile X-linked retinoschisis (RS1, OMIM: 312700) is a hereditary vitreoretinal dystrophy characterized by bilateral foveal schisis and, in half of the patients, splitting through the nerve fiber layer in the peripheral retina. In the first decade of life, patients usually develop a decrease in visual acuity. Long-term visual outcomes can be poor due to the limited number of known successful treatments. The purposes of this study were to present, for the first time, a p.Arg197Cys missense mutation in the RS1 gene (OMIM: 300839) in a four-generation Italian family with RS1 and to examine the clinical response to the treatment with acetazolamide tablets alone or in combination with dorzolamide eye drops as assessed by spectral-domain optical coherence tomography (SD-OCT). Eleven individuals, including two brothers with RS1 (patients 1 and 2), underwent a full medical history examination and a comprehensive ocular assessment that involved SD-OCT, fluorescein angiography, electroretinography and DNA analysis. Each RS1 patient received oral acetazolamide (375 mg daily) during the first three months. Thereafter, patient 1 continued only with dorzolamide eyedrops three times a day for a period of three months, while patient 2 spontaneously stopped both medications. Sequence analysis of the RS1 gene identified a hemizygous c.589C>T (p.Arg197Cys) missense mutation in exon 6, which has not been previously reported in an Italian family. A different response to the medical therapy was observed in the four eyes of the two affected brothers hemizygous for this abnormality. Of note, after acetazolamide interruption, a rebound effect on cystoid macular edema reduced the beneficial effects of the initial therapy for RS1 from p.Arg197Cys mutation. Indeed, a minimal rebound effect on cystoid macular edema, and an improvement in visual acuity, was observed in patient 1 during the six months of treatment. Conversely, in patient 2, an initial improvement in cystoid macular edema was

Pressure signature and evaluation of hammer pulses during underwater implosion in confining environments.

PubMed

Gupta, Sachin; Matos, Helio; Shukla, Arun; LeBlanc, James M

2016-08-01

The fluid structure interaction phenomenon occurring in confined implosions is investigated using high-speed three-dimensional digital image correlation (DIC) experiments. Aluminum tubular specimens are placed inside a confining cylindrical structure that is partially open to a pressurized environment. These specimens are hydrostatically loaded until they naturally implode. The implosion event is viewed, and recorded, through an acrylic window on the confining structure. The velocities captured through DIC are synchronized with the pressure histories to understand the effects of confining environment on the implosion process. Experiments show that collapse of the implodable volume inside the confining tube leads to strong oscillating water hammer waves. The study also reveals that the increasing collapse pressure leads to faster implosions. Both peak and average structural velocities increase linearly with increasing collapse pressure. The effects of the confining environment are better seen in relatively lower collapse pressure implosion experiments in which a long deceleration phase is observed following the peak velocity until wall contact initiates. Additionally, the behavior of the confining environment can be viewed and understood through classical water hammer theory. A one-degree-of-freedom theoretical model was created to predict the impulse pressure history for the particular problem studied.

Child health in the workplace: the Supreme Court in Hammer v. Dagenhart (1918).

PubMed

Berger, L R; Johansson, S R

1980-01-01

Exploitation of children in the labor force at the beginning of this century gave rise to a national campaign leading to congressional passage of the Keating-Owen Act in 1916. The act prohibited from interstate commerce goods produced in factories or mines that employed children who either were under fourteen years of age or who were under sixteen years of age and worked more than eight hours a day. Despite its popular support, the Act was declared unconstitutional by the Supreme Court in Hammer v. Dagenhart (1918). The Court's decision involved several major issues: interpretation of the Fifth and Fourteenth Amendments to the Constitution, freedom of contract, police power of the states, and the interstate commerce clause. Review of previous Court decisions suggests that the justices were on less than solid legal ground in reaching their decision. Examination of the historical context of the decision, however, suggests other factors that may have played a more important role than judicial precedents. The debate prompted by Hammer v. Dagenhart has much relevance to such current issues as young agricultural workers, sex discrimination in industry, and the powers of the federal government vis-a-vis states and individual citizens.

Magnitude of virologic blips is associated with a higher risk for virologic rebound in HIV-infected individuals: a recurrent events analysis.

PubMed

Grennan, J Troy; Loutfy, Mona R; Su, DeSheng; Harrigan, P Richard; Cooper, Curtis; Klein, Marina; Machouf, Nima; Montaner, Julio S G; Rourke, Sean; Tsoukas, Christos; Hogg, Bob; Raboud, Janet

2012-04-15

The importance of human immunodeficiency virus (HIV) blip magnitude on virologic rebound has been raised in clinical guidelines relating to viral load assays. Antiretroviral-naive individuals initiating combination antiretroviral therapy (cART) after 1 January 2000 and achieving virologic suppression were studied. Negative binomial models were used to identify blip correlates. Recurrent event models were used to determine the association between blips and rebound by incorporating multiple periods of virologic suppression per individual. 3550 participants (82% male; median age, 40 years) were included. In a multivariable negative binomial regression model, the Amplicor assay was associated with a lower blip rate than branched DNA (rate ratio, 0.69; P < .01), controlling for age, sex, region, baseline HIV-1 RNA and CD4 count, AIDS-defining illnesses, year of cART initiation, cART type, and HIV-1 RNA testing frequency. In a multivariable recurrent event model controlling for age, sex, intravenous drug use, cART start year, cART type, assay type, and HIV-1 RNA testing frequency, blips of 500-999 copies/mL were associated with virologic rebound (hazard ratio, 2.70; P = .002), whereas blips of 50-499 were not. HIV-1 RNA assay was an important determinant of blip rates and should be considered in clinical guidelines. Blips ≥500 copies/mL were associated with increased rebound risk.

Water hammer caused by closure of turbine safety spherical valves

NASA Astrophysics Data System (ADS)

Karadžić, U.; Bergant, A.; Vukoslavčević, P.

2010-08-01

This paper investigates water hammer effects caused by closure of spherical valves against the discharge. During the first phase of modernisation of Perućica high-head hydropower plant (HPP), Montenegro, safety spherical valves (inlet turbine valves) have been refurbished on the first two Pelton turbine units. The valve closure is controlled by the valve actuator (hydraulic servomotor). Because the torque acting on the valve body is dependent on flow conditions the valve closing time may vary significantly for different flow velocities (passive valve). For the passive valve the torques acting on the valve body should be considered in the valve model. The valve closing time results from numerical simulation. On the contrary, for the active valve the valve closing time is assumed prior to simulation. The spherical valve boundary condition is incorporated into the method of characteristics (MOC) algorithm. The staggered (diamond) grid in applying the MOC is used in this paper. The passive valve boundary condition is described by the water hammer equations, the valve equation that relates discharge to pressure head drop and the dynamic equation of the valve body motion (torque equation). The active valve boundary condition is described by the first two equations, respectively. Standard quasi-steady friction model is used for estimating friction losses in plant's tunnel and penstocks. Numerical results using both the active and the passive spherical valve models are compared with results of measurements. It has been found that the influence of flow conditions on the spherical valve closing time is minor for the cases considered. Computed and measured results agree reasonably well.

Genome Sequence of the Thermophile Bacillus coagulans Hammer, the Type Strain of the Species

PubMed Central

Su, Fei; Tao, Fei; Tang, Hongzhi

2012-01-01

Here we announce a 3.0-Mb assembly of the Bacillus coagulans Hammer strain, which is the type strain of the species within the genus Bacillus. Genomic analyses based on the sequence may provide insights into the phylogeny of the species and help to elucidate characteristics of the poorly studied strains of Bacillus coagulans. PMID:23105047

2011 Mound Site Groundwater Plume Rebound Exercise and Follow-Up - 13440

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

Hooten, Gwendolyn; Cato, Rebecca; Lupton, Greg

2013-07-01

The Mound Site facility near Miamisburg, Ohio, opened in 1948 to support early atomic weapons programs. It grew into a research, development, and production facility performing work in support of the U.S. Department of Energy (DOE) weapons and energy programs. The plant was in operation until 1995. During the course of operation, an onsite landfill was created. The landfill was located over a finger of a buried valley aquifer, which is a sole drinking water source for much of the Miami Valley. In the 1980's, volatile organic compounds (VOCs) were discovered in groundwater at the Mound site. The site wasmore » placed on the National Priorities List on November 21, 1989. DOE signed a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Federal Facility Agreement with the U.S. Environmental Protection Agency (EPA) and the Ohio Environmental Protection Agency. The agreement became effective in October 1990. The area that included the landfill was designated Operational Unit 1 (OU-1). In 1995, a Record of Decision was signed that called for the installation and operation of a pump and treatment (P and T) system in order to prevent the VOCs in OU-1 groundwater from being captured by the onsite water production wells. In addition to the P and T system, a soil vapor extraction (SVE) system was installed in 1997 to accelerate removal of VOCs from groundwater in the OU-1 area. The SVE system was successful in removing large amounts of VOCs and continued to operate until 2007, when the amount of VOCs removed became minimal. A rebound study was started in February 2003 to determine how the groundwater system and contaminants would respond to shutting down the P and T system. The rebound test was stopped in February 2004 because predetermined VOC threshold concentrations were exceeded down-gradient of the landfill. The P and T and SVE systems were restarted after the termination of the rebound test. In 2006, the remediation of the Mound site was

Surface tension effects on the behavior of a cavity growing, collapsing, and rebounding near a rigid wall.

PubMed

Zhang, Zhen-yu; Zhang, Hui-sheng

2004-11-01

Surface tension effects on the behavior of a pure vapor cavity or a cavity containing some noncondensible contents, which is growing, collapsing, and rebounding axisymmetrically near a rigid wall, are investigated numerically by the boundary integral method for different values of dimensionless stand-off parameter gamma, buoyancy parameter delta, and surface tension parameter beta. It is found that at the late stage of the collapse, if the resultant action of the Bjerknes force and the buoyancy force is not small, surface tension will not have significant effects on bubble behavior except that the bubble collapse time is shortened and the liquid jet becomes wider. If the resultant action of the two force is small enough, surface tension will have significant and in some cases substantial effects on bubble behavior, such as changing the direction of the liquid jet, making a new liquid jet appear, in some cases preventing the bubble from rebound before jet impact, and in other cases causing the bubble to rebound or even recollapse before jet impact. The mechanism of surface tension effects on the collapsing behavior of a cavity has been analyzed. The mechanisms of some complicated phenomena induced by surface tension effects are illustrated by analysis of the computed velocity fields and pressure contours of the liquid flow outside the bubble at different stages of the bubble evolution.

Dynamic Brazilian Test of Rock Under Intermediate Strain Rate: Pendulum Hammer-Driven SHPB Test and Numerical Simulation

NASA Astrophysics Data System (ADS)

Zhu, W. C.; Niu, L. L.; Li, S. H.; Xu, Z. H.

2015-09-01

The tensile strength of rock subjected to dynamic loading constitutes many engineering applications such as rock drilling and blasting. The dynamic Brazilian test of rock specimens was conducted with the split Hopkinson pressure bar (SHPB) driven by pendulum hammer, in order to determine the indirect tensile strength of rock under an intermediate strain rate ranging from 5.2 to 12.9 s-1, which is achieved when the incident bar is impacted by pendulum hammer with different velocities. The incident wave excited by pendulum hammer is triangular in shape, featuring a long rising time, and it is considered to be helpful for achieving a constant strain rate in the rock specimen. The dynamic indirect tensile strength of rock increases with strain rate. Then, the numerical simulator RFPA-Dynamics, a well-recognized software for simulating the rock failure under dynamic loading, is validated by reproducing the Brazilian test of rock when the incident stress wave retrieved at the incident bar is input as the boundary condition, and then it is employed to study the Brazilian test of rock under the higher strain rate. Based on the numerical simulation, the strain-rate dependency of tensile strength and failure pattern of the Brazilian disc specimen under the intermediate strain rate are numerically simulated, and the associated failure mechanism is clarified. It is deemed that the material heterogeneity should be a reason for the strain-rate dependency of rock.

Rebound mechanics of micrometre-scale, spherical particles in high-velocity impacts.

PubMed

Yildirim, Baran; Yang, Hankang; Gouldstone, Andrew; Müftü, Sinan

2017-08-01

The impact mechanics of micrometre-scale metal particles with flat metal surfaces is investigated for high-velocity impacts ranging from 50 m s -1 to more than 1 km s -1 , where impact causes predominantly plastic deformation. A material model that includes high strain rate and temperature effects on the yield stress, heat generation due to plasticity, material damage due to excessive plastic strain and heat transfer is used in the numerical analysis. The coefficient of restitution e is predicted by the classical work using elastic-plastic deformation analysis with quasi-static impact mechanics to be proportional to [Formula: see text] and [Formula: see text] for the low and moderate impact velocities that span the ranges of 0-10 and 10-100 m s -1 , respectively. In the elastic-plastic and fully plastic deformation regimes the particle rebound is attributed to the elastic spring-back that initiates at the particle-substrate interface. At higher impact velocities (0.1-1 km s -1 ) e is shown to be proportional to approximately [Formula: see text]. In this deeply plastic deformation regime various deformation modes that depend on plastic flow of the material including the time lag between the rebound instances of the top and bottom points of particle and the lateral spreading of the particle are identified. In this deformation regime, the elastic spring-back initiates subsurface, in the substrate.

Rebound weight gain as associated with high plasma norepinephrine levels that are mediated through polymorphisms in the beta2-adrenoceptor.

PubMed

Masuo, Kazuko; Katsuya, Tomohiro; Kawaguchi, Hideki; Fu, Yuxiao; Rakugi, Hiromi; Ogihara, Toshio; Tuck, Michael L

2005-11-01

A successful weight loss program is essential treatment for obesity-related diseases, but it is well known that the majority of individuals do not succeed in weight loss maintenance. The present study evaluates hormonal mechanisms and the relationship of beta2-adrenoceptor polymorphisms involved in individuals who regain weight after initially successful weight loss. Overweight Japanese men (n = 154) were enrolled in a 24-month weight loss program. Body mass index (BMI), total body fat mass, plasma norepinephrine (NE) and leptin levels, and beta2-adrenoceptor polymorphisms (Arg16Gly, Gln27Glu) were measured every 6 months for the 24-month period. Maintenance of weight loss was defined as significant weight loss (>or=10% reduction) from entry weight at 6 months and maintenance of the weight loss for an additional 18 months. Rebound weight gain was defined as significant weight loss at 6 months but subsequent regain of body weight during the next 18 months. The results showed that 37 subjects maintained weight loss during 24 months, whereas 36 subjects had rebound weight gain. The BMI at entry and calorie intake and physical activity at each period were similar between the two groups. Subjects who maintained weight loss had at entry a significantly lower fat mass and plasma NE levels compared to those with rebound weight gain. Body fat mass, NE, and leptin levels at entry predicted the degree of change in body weight during the 24-month study period. Subjects with rebound weight gain had a significantly higher frequency of the Gly16 allele for the beta2-adrenoceptor polymorphism compared to subjects who had a 24-month maintenance of weight loss. Subjects carrying the Gly16 allele also had significantly higher plasma NE, leptin, and body fat mass levels and a greater waist-to-hip ratio both at entry and throughout the study. A high initial degree of body fat mass and high plasma NE levels as determined by the Gly16 allele for the beta2-adrenoceptor polymorphisms

Recent Earth oblateness variations: unraveling climate and postglacial rebound effects.

PubMed

Dickey, Jean O; Marcus, Steven L; de Viron, Olivier; Fukumori, Ichiro

2002-12-06

Earth's dynamic oblateness (J2) has been decreasing due to postglacial rebound (PGR). However, J2 began to increase in 1997, indicating a pronounced global-scale mass redistribution within Earth's system. We have determined that the observed increases in J2 are caused primarily by a recent surge in subpolar glacial melting and by mass shifts in the Southern, Pacific, and Indian oceans. When these effects are removed, the residual trend in J2 (-2.9 x 10(-11) year-1) becomes consistent with previous estimates of PGR from satellite and eclipse data. The climatic significance of these rapid shifts in glacial and oceanic mass, however, remains to be investigated.

Postseismic rebound in fault step-overs caused by pore fluid flow

USGS Publications Warehouse

Peltzer, G.; Rosen, P.; Rogez, F.; Hudnut, K.

1996-01-01

Near-field strain induced by large crustal earthquakes results in changes in pore fluid pressure that dissipate with time and produce surface deformation. Synthetic aperture radar (SAR) interferometry revealed several centimeters of postseismic uplift in pull-apart structures and subsidence in a compressive jog along the Landers, California, 1992 earthquake surface rupture, with a relaxation time of 270 ?? 45 days. Such a postseismic rebound may be explained by the transition of the Poisson's ratio of the deformed volumes of rock from undrained to drained conditions as pore fluid flow allows pore pressure to return to hydrostatic equilibrium.

Follow-up of hearing thresholds among forge hammering workers

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

Kamal, A.A.; Mikael, R.A.; Faris, R.

Hearing threshold was reexamined in a group of forge hammering workers investigated 8 years ago with consideration of the age effect and of auditory symptoms. Workers were exposed to impact noise that ranged from 112 to 139 dB(A)--at an irregular rate of 20 to 50 drop/minute--and a continuous background noise that ranged from 90 to 94 dB(A). Similar to what was observed 8 years ago, the present permanent threshold shift (PTS) showed a maximum notch at the frequency of 6 kHz and considerable elevations at the frequencies of 0.25-1 kHz. The age-corrected PTS and the postexposure hearing threshold were significantlymore » higher than the corresponding previous values at the frequencies 0.25, 0.5, 1, and 8 kHz only. The rise was more evident at the low than at the high frequencies. Temporary threshold shift (TTS) values were significantly less than those 8 years ago. Contrary to the previous TTS, the present TTS were higher at low than at high frequencies. Although progression of PTS at the frequencies 0.25 and 0.5 kHz was continuous throughout the observed durations of exposure, progression at higher frequencies occurred essentially in the first 10 to 15 years of exposure. Thereafter, it followed a much slower rate. Tinnitus was significantly associated with difficulty in hearing the human voice and with elevation of PTS at all the tested frequencies, while acoustic after-image was significantly associated with increment of PTS at the frequencies 0.25-2 kHz. No relation between PTS and smoking was found. PTS at low frequencies may provide an indication of progression of hearing damage when the sensitivity at 6 and 4 kHz diminishes after prolonged years of exposure. Tinnitus and acoustic after-image are related to the auditory effect of forge hammering noise.« less

What's Tramadol Got to Do with It? A Case Report of Rebound Hypoglycemia, a Reappraisal and Review of Potential Mechanisms.

PubMed

Odonkor, Charles A; Chhatre, Akhil

2016-01-01

Tramadol has gained traction as an analgesic of choice among pain practicing physicians. However some concerns regarding a previously unlabeled adverse reaction - hypoglycemia - have cast it in a dim light. Prior reports have noted an associated risk of hospitalization for hypoglycemia after tramadol use, but whether tramadol is the main causal agent is poorly understood and the underlying mechanisms are not well delineated. We present a unique case of rebound hypoglycemia as a variation of the theme of tramadol's adverse effect profile in a patient with type 1 diabetes mellitus, and reappraise potential mechanisms underlying this underappreciated phenomenon. A 71-year-old woman presented with right buttock pain and right lateral leg discomfort of 9-month duration. Her physical exam suggested sacroiliac joint (SIJ) etiology, confirmed by magnetic resonance imaging (MRI). She was scheduled for an SIJ-diagnostic and therapeutic block and started on tramadol 50 mg 3 times daily on as needed basis. The patient subsequently developed severe hypoglycemia initially resistant to euglycemia restorative interventions with a rebound episode. Hypoglycemia resolved with oral ingestion of high levels of glucose and the patient was taken off tramadol. Fortunately, she did not require hospitalization. The clinical scenario described is a case of rebound hypoglycemia after tramadol use in a patient with type-1 diabetes naïve to opioid analgesics. The episodes of hypoglycemia aligned perfectly with the anticipated pharmacodynamic and pharmacokinetic properties of tramadol. The specificity and temporality of events after tramadol use in this patient fulfilled causality criteria. Tramadol may cause rebound hypoglycemia in patients via interference of the intrinsic euglycemia-restoration pathways and a blunted autonomic counter-regulatory response to antecedent hypoglycemia. Its use must be tempered by this underappreciated adverse effect profile.Key words: Tramadol, hypoglycemia

Rebound increase in seizure susceptibility but not isolation-induced calls after single administration of clonazepam and Ro 19-8022 in infant rats.

PubMed

Mikulecká, A; Mareš, P; Kubová, H

2011-01-01

The purpose of our study was to determine whether a single administration of anticonvulsant doses of two ligands of benzodiazepine receptors, clonazepam and Ro 19-8022, leads to development of rebound phenomena in immature 12-day-old rats. Three tests were used: pentylenetetrazole (PTZ)-induced seizures, isolation-induced ultrasonic vocalizations, and motor performance. Susceptibility to the convulsant effects of PTZ decreased 24 hours, but increased 48 hours, after clonazepam administration. Ultrasonic vocalizations were completely suppressed 30 minutes and 3 hours after clonazepam; a moderate inhibitory effect persisted even at 48 hours. Motor abilities were slightly compromised up to 3 hours. Similar effects of Ro 19-8022 on PTZ-induced seizures and ultrasonic vocalizations were observed 24 and 48 hours after administration; motor performance was not affected. Rebound proconvulsant effects followed different time courses after administration of the two benzodiazepine receptor ligands in developing animals. Anxiolytic-like effects of these drugs were still present at the time when animals exhibited rebound proconvulsant effects. Copyright © 2010 Elsevier Inc. All rights reserved.

The stomatopod dactyl club: a formidable damage-tolerant biological hammer.

PubMed

Weaver, James C; Milliron, Garrett W; Miserez, Ali; Evans-Lutterodt, Kenneth; Herrera, Steven; Gallana, Isaias; Mershon, William J; Swanson, Brook; Zavattieri, Pablo; DiMasi, Elaine; Kisailus, David

2012-06-08

Nature has evolved efficient strategies to synthesize complex mineralized structures that exhibit exceptional damage tolerance. One such example is found in the hypermineralized hammer-like dactyl clubs of the stomatopods, a group of highly aggressive marine crustaceans. The dactyl clubs from one species, Odontodactylus scyllarus, exhibit an impressive set of characteristics adapted for surviving high-velocity impacts on the heavily mineralized prey on which they feed. Consisting of a multiphase composite of oriented crystalline hydroxyapatite and amorphous calcium phosphate and carbonate, in conjunction with a highly expanded helicoidal organization of the fibrillar chitinous organic matrix, these structures display several effective lines of defense against catastrophic failure during repetitive high-energy loading events.

The Stomatopod Dactyl Club: A Formidable Damage-Tolerant Biological Hammer

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

Weaver J. C.; DiMasi E.; Milliron, G.W.

2012-06-08

Nature has evolved efficient strategies to synthesize complex mineralized structures that exhibit exceptional damage tolerance. One such example is found in the hypermineralized hammer-like dactyl clubs of the stomatopods, a group of highly aggressive marine crustaceans. The dactyl clubs from one species, Odontodactylus scyllarus, exhibit an impressive set of characteristics adapted for surviving high-velocity impacts on the heavily mineralized prey on which they feed. Consisting of a multiphase composite of oriented crystalline hydroxyapatite and amorphous calcium phosphate and carbonate, in conjunction with a highly expanded helicoidal organization of the fibrillar chitinous organic matrix, these structures display several effective lines ofmore » defense against catastrophic failure during repetitive high-energy loading events.« less

Can Satellite Geodesy Disentangle Holocene Rebound and Present-Day Glacier Balance Signatures?

NASA Technical Reports Server (NTRS)

Irvins, E.; James, T.; Yoder, C.

1995-01-01

The secular drift of the precession of the ascending node of the LAGOES -1 satellite is apparently linked to the Earth s paleoclimate through the slow viscous response of the mantle to ice sheet/ocean mass transfer during the last great continental deglaciation . The secular node acceleration is particularly sensitive to the longest wavelengths of the paleo -surface loading that have been memorized by the mantle glacio -isostatic flow. Tide gauge records for the last 130 years show a post-glacial rebound-corrected sea-level rise of 2.4 n 0.9 mm yr-1.

Rumination and Rebound from Failure as a Function of Gender and Time on Task

PubMed Central

Whiteman, Ronald C.; Mangels, Jennifer A.

2016-01-01

Rumination is a trait response to blocked goals that can have positive or negative outcomes for goal resolution depending on where attention is focused. Whereas “moody brooding” on affective states may be maladaptive, especially for females, “reflective pondering” on concrete strategies for problem solving may be more adaptive. In the context of a challenging general knowledge test, we examined how Brooding and Reflection rumination styles predicted students’ subjective and event-related responses (ERPs) to negative feedback, as well as use of this feedback to rebound from failure on a later surprise retest. For females only, Brooding predicted unpleasant feelings after failure as the task progressed. It also predicted enhanced attention to errors through both bottom-up and top-down processes, as indexed by increased early (400–600 ms) and later (600–1000 ms) late positive potentials (LPP), respectively. Reflection, despite increasing females’ initial attention to negative feedback (i.e., early LPP), as well as both genders’ recurring negative thoughts, did not result in sustained top-down attention (i.e., late LPP) or enhanced negative feelings toward errors. Reflection also facilitated rebound from failure in both genders, although Brooding did not hinder it. Implications of these gender and time-related rumination effects for learning in challenging academic situations are discussed. PMID:26901231

Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill

NASA Technical Reports Server (NTRS)

Sherrit, Stewart (Inventor); Bao, Xiaoqi (Inventor); Badescu, Mircea (Inventor); Bar-Cohen, Yoseph (Inventor)

2014-01-01

A Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill includes a horn actuator having high power piezoelectric materials and a flexure pre-stress to increase the actuators effectiveness. The drill is a low mass, low power, compact coring drill measuring 20-cm high by 7-cm diameter and having a total weight of 2 kg including drive electronics. Using an average power of 50-Watts, the drill basalt is expected to cut basalt at a rate of 0.2 cm/min down to depth of 10-cm and create cuttings and an intact core. The drill is expected to operate under different environments including Martian ambient (6 Torr and down to -50 degree C), and liquid nitrogen temperatures (77 K) and low pressure (<<1 Torr) to simulate lunar polar and Europa conditions. Materials expected to be sampled include Kaolinite, Saddleback Basalt, Limestone, Volcanic Breccia, Siltstone, ice, permafrost and layered rocks with different hardness.

Computation of water hammer protection of modernized pumping station

NASA Astrophysics Data System (ADS)

Himr, Daniel

2014-03-01

Pumping station supplies water for irrigation. Maximal capacity 2 × 1.2m3·s-1 became insufficient, thus it was upgraded to 2 × 2m3·s-1. Paper is focused on design of protection against water hammer in case of sudden pumps trip. Numerical simulation of the most dangerous case (when pumps are giving the maximal flow rate) showed that existing air vessels were not able to protect the system and it would be necessary to add new vessels. Special care was paid to influence of their connection to the main pipeline, because the resistance of the connection has a significant impact on the scale of pressure pulsations. Finally, the pump trip was performed to verify if the system worked correctly. The test showed that pressure pulsations are lower (better) than computation predicted. This discrepancy was further analysed.

Variable Step Integration Coupled with the Method of Characteristics Solution for Water-Hammer Analysis, A Case Study

NASA Technical Reports Server (NTRS)

Turpin, Jason B.

2004-01-01

One-dimensional water-hammer modeling involves the solution of two coupled non-linear hyperbolic partial differential equations (PDEs). These equations result from applying the principles of conservation of mass and momentum to flow through a pipe, and usually the assumption that the speed at which pressure waves propagate through the pipe is constant. In order to solve these equations for the interested quantities (i.e. pressures and flow rates), they must first be converted to a system of ordinary differential equations (ODEs) by either approximating the spatial derivative terms with numerical techniques or using the Method of Characteristics (MOC). The MOC approach is ideal in that no numerical approximation errors are introduced in converting the original system of PDEs into an equivalent system of ODEs. Unfortunately this resulting system of ODEs is bound by a time step constraint so that when integrating the equations the solution can only be obtained at fixed time intervals. If the fluid system to be modeled also contains dynamic components (i.e. components that are best modeled by a system of ODEs), it may be necessary to take extremely small time steps during certain points of the model simulation in order to achieve stability and/or accuracy in the solution. Coupled together, the fixed time step constraint invoked by the MOC, and the occasional need for extremely small time steps in order to obtain stability and/or accuracy, can greatly increase simulation run times. As one solution to this problem, a method for combining variable step integration (VSI) algorithms with the MOC was developed for modeling water-hammer in systems with highly dynamic components. A case study is presented in which reverse flow through a dual-flapper check valve introduces a water-hammer event. The predicted pressure responses upstream of the check-valve are compared with test data.

Drop Hammer Tests with Three Oleo Strut Models and Three Different Shock Strut Oils at Low Temperatures

NASA Technical Reports Server (NTRS)

Kranz, M

1954-01-01

Drop hammer tests with different shock strut models and shock strut oils were performed at temperatures ranging to -40 C. The various shock strut models do not differ essentially regarding their springing and damping properties at low temperatures; however, the influence of the different shock strut oils on the springing properties at low temperatures varies greatly.

Numerical simulation of water hammer in low pressurized pipe: comparison of SimHydraulics and Lax-Wendroff method with experiment

NASA Astrophysics Data System (ADS)

Himr, D.

2013-04-01

Article describes simulation of unsteady flow during water hammer with two programs, which use different numerical approaches to solve ordinary one dimensional differential equations describing the dynamics of hydraulic elements and pipes. First one is Matlab-Simulink-SimHydraulics, which is a commercial software developed to solve the dynamics of general hydraulic systems. It defines them with block elements. The other software is called HYDRA and it is based on the Lax-Wendrff numerical method, which serves as a tool to solve the momentum and continuity equations. This program was developed in Matlab by Brno University of Technology. Experimental measurements were performed on a simple test rig, which consists of an elastic pipe with strong damping connecting two reservoirs. Water hammer is induced with fast closing the valve. Physical properties of liquid and pipe elasticity parameters were considered in both simulations, which are in very good agreement and differences in comparison with experimental data are minimal.

Effect of Rebound Exercises and Circuit Training on Complications Associated with Type 2 Diabetes: Protocol for a Randomized Controlled Trial.

PubMed

Kaka, Bashir; Maharaj, Sonill Sooknunan

2018-05-07

The incidence of type 2 diabetes mellitus, a chronic lifestyle disease, and its complications are on the rise. Exercise has been documented as being effective in the management of musculoskeletal pain, depression, and reduction of hyperglycemia in diabetic patients. However, there is no consensus regarding the types of exercise that reduce musculoskeletal pain and depression and improve quality of life as well as respiratory function among individuals with type 2 diabetes. The objective of this study is to determine the effects of rebound and circuit training on musculoskeletal pain, blood glucose level, cholesterol level, quality of life, depression, and respiratory parameters in patients with type 2 diabetes mellitus. A total of 70 participants are expected to be recruited in this single blind randomized controlled trial. Computer-generated random numbers will be used to randomize the participants into 3 groups, namely, the rebound exercise group, the circuit exercise group, and the control group. Measurements will be taken at baseline and at the end of the 8 weeks of the study. Participants' musculoskeletal pain will be assessed using the visual analog scale, quality of life will be assessed using the SF 12 Health Survey Questionnaire, depression using the Beck Depression Inventory, respiratory parameters using the spirometer, and biochemical parameters such as glucose level and cholesterol level using the glucometer. Data will be analyzed using descriptive statistics and inferential statistics of multivariate analysis of variance between the groups and paired t test within the group. Alpha will be set at .05. The results of this study will identify the effectiveness of rebound exercise and circuit training, compared with the control, in the management of type 2 diabetes mellitus and on quality of life, musculoskeletal pain, depression, glycemic control, cholesterol level, as well as improvement in respiratory function. Though different additional strategies

Initial recovery and rebound of type f intestinal colonization botulism after administration of investigational heptavalent botulinum antitoxin.

PubMed

Fagan, Ryan P; Neil, Karen P; Sasich, Randy; Luquez, Carolina; Asaad, Hakam; Maslanka, Susan; Khalil, Wajahat

2011-11-01

Investigational heptavalent botulinum antitoxin (HBAT) is now the primary antitoxin for US noninfant botulism patients. HBAT consists of equine Fab/F(ab')2 IgG fragments, which are cleared from circulation faster than whole immunoglobulins. Rebound botulism after antitoxin administration is not previously documented but occurred in our patient 10 days after HBAT administration.

Butyrylcholinesterase gene transfer in obese mice prevents postdieting body weight rebound by suppressing ghrelin signaling.

PubMed

Chen, Vicky Ping; Gao, Yang; Geng, Liyi; Brimijoin, Stephen

2017-10-10

The worldwide prevalence of obesity is increasing at an alarming rate but treatment options remain limited. Despite initial success, weight loss by calorie restriction (CR) often fails because of rebound weight gain. Postdieting hyperphagia along with altered hypothalamic neuro-architecture appears to be one direct cause of this undesirable outcome. In response to calorie deficiency the circulating levels of the appetite-promoting hormone, acyl-ghrelin, rise sharply. We hypothesize that proper modulation of acyl-ghrelin and its receptor's sensitivity will favorably impact energy intake and reprogram the body weight set point. Here we applied viral gene transfer of the acyl-ghrelin hydrolyzing enzyme, butyrylcholinesterase (BChE), in a mouse model of diet-induced obesity. Our results confirmed that BChE overexpression decreased circulating acyl-ghrelin levels, suppressed CR-provoked ghrelin signaling, and restored central ghrelin sensitivity. In addition to maintaining healthy body weights, BChE treated mice had modest postdieting food intake and showed normal glucose homeostasis. Spontaneous activity and energy expenditure did not differ significantly between treated and untreated mice after body weight rebound, suggesting that BChE gene transfer did not alter energy expenditure in the long term. These findings indicate that combining BChE treatment with CR could be an effective approach in treating human obesity and aiding lifelong weight management.

How Long Does the Benefit of Biologics Last? An Update on Time To Relapse and Potential for Rebound of Biologic Agents for Psoriasis.

PubMed

Kamaria, Monique; Liao, Wilson; Koo, J Y

2010-01-01

The biologic agents vary considerably in terms of their long-term duration of effect. Using the definitions provided by the National Psoriasis Foundation Medical Board, the objective of this review was to compare all biologic agents with respect to time to relapse and potential for rebound. Overall, alefacept had the longest off-treatment benefit (29.9 weeks in Psoriasis Area and Severity Index [PASI] 75 responders), followed by ustekinumab (22 weeks), infliximab (19.5 weeks), adalimumab (18 weeks), etanercept (12.1 weeks in PASI 50 responders), and, lastly, efalizumab (9.6 weeks). Rebound was reported commonly for efalizumab (14%) and, extremely rarely, for etanercept (0.002%).

Linkage and retention in care and the time to HIV viral suppression and viral rebound - New York City.

PubMed

Robertson, McKaylee; Laraque, Fabienne; Mavronicolas, Heather; Braunstein, Sarah; Torian, Lucia

2015-01-01

The success of antiretroviral therapy (ART) as treatment for the individual patient and as prevention requires the achievment and maintenance of human immunodeficiency virus (HIV) viral suppression. Linkage to and retention in care are required for access to ART. We describe the impact of care on viral suppression using routinely reported surveillance data. We included New York City residents ≥13 years of age, diagnosed with HIV/AIDS from 1 July 2005 to 30 June 2009 with a viral load (VL) or CD4 reported within six months of diagnosis and ≥1 VL reported from 1 July 2005 to 30 June 2011. To examine viral rebound, we restricted the analysis to those who achieved viral suppression and had a subsequent VL measure reported by 30 June 2011. Cox proportional hazards models were used to evaluate factors associated with time to viral suppression (VL ≤ 400 copies/mL) and rebound (VL > 1000 copies/mL). Initiation of care within three months of diagnosis (CD4/VL report within three months of diagnosis), female sex, and an initial CD4 < 350 (cells/mm(3)) at diagnosis significantly increased the likelihood of viral suppression. Irregular care (no CD4/VL reported every six months), younger age, non-white race/ethnicity, having an initial CD4 ≥ 350 at diagnosis, and AIDS diagnosis by 2010 increased the likelihood of rebound. These findings lend support to interventions for improving linkage to and maintenance in regular care as a way to achieve and maintain suppression. Surveillance data represent an ideal means for monitoring engagement in care and viral suppression at the population level.

Acute effects of vibration from a chipping hammer and a grinder on the hand-arm system.

PubMed Central

Kihlberg, S; Attebrant, M; Gemne, G; Kjellberg, A

1995-01-01

OBJECTIVES--The purpose of this study was to compare various effects on the hand-arm system of vibration exposure from a chipping hammer and a grinder with the same frequency weighted acceleration. Grip and push forces were measured and monitored during the exposure. The various effects were: muscle activity (measured with surface electrodes), discomfort ratings for different parts of the hand-arm system (made during and after exposure), and vibration perception threshold (for 10 minutes before and 10 minutes after the exposure). RESULTS--No increase in muscle activity due to exposure to vibration was found in the hand muscle studied. In the forearm, conversely, there was an increase in both muscle studied. For the upper arm the muscle activity only increased when exposed to impact vibration. Subjective ratings in the hand and shift in vibration perception threshold were effected more by the grinder than the hammer exposure. CONCLUSION--These results show that the reaction of the hand-arm system to vibration varies with frequency quantitatively as well as qualitatively. They do not support the notion that one single frequency weighted curve would be valid for the different health effects of hand-arm vibration (vascular, musculoskeletal, neurological, and psychophysiological). PMID:8535492

Butyrylcholinesterase gene transfer in obese mice prevents postdieting body weight rebound by suppressing ghrelin signaling

PubMed Central

Chen, Vicky Ping; Gao, Yang; Geng, Liyi; Brimijoin, Stephen

2017-01-01

The worldwide prevalence of obesity is increasing at an alarming rate but treatment options remain limited. Despite initial success, weight loss by calorie restriction (CR) often fails because of rebound weight gain. Postdieting hyperphagia along with altered hypothalamic neuro-architecture appears to be one direct cause of this undesirable outcome. In response to calorie deficiency the circulating levels of the appetite-promoting hormone, acyl-ghrelin, rise sharply. We hypothesize that proper modulation of acyl-ghrelin and its receptor’s sensitivity will favorably impact energy intake and reprogram the body weight set point. Here we applied viral gene transfer of the acyl-ghrelin hydrolyzing enzyme, butyrylcholinesterase (BChE), in a mouse model of diet-induced obesity. Our results confirmed that BChE overexpression decreased circulating acyl-ghrelin levels, suppressed CR-provoked ghrelin signaling, and restored central ghrelin sensitivity. In addition to maintaining healthy body weights, BChE treated mice had modest postdieting food intake and showed normal glucose homeostasis. Spontaneous activity and energy expenditure did not differ significantly between treated and untreated mice after body weight rebound, suggesting that BChE gene transfer did not alter energy expenditure in the long term. These findings indicate that combining BChE treatment with CR could be an effective approach in treating human obesity and aiding lifelong weight management. PMID:28973869

Platelet rebound effect of alcohol withdrawal and wine drinking in rats. Relation to tannins and lipid peroxidation.

PubMed

Ruf, J C; Berger, J L; Renaud, S

1995-01-01

We investigated in rats fed a purified diet for 2 and 4 months whether wine drinking was associated with the rebound effect on thrombin-induced platelet aggregation observed after alcohol withdrawal. With 6% ethanol drinking or its equivalent in red or white wine, platelet aggregation was reduced similarly by 70% when the animals drank the alcoholic beverages up to the venipuncture. Depriving the rats of alcoholic beverages for 18 hours was associated with an increase in the platelet response of 124% in those receiving 6% ethanol, of 46% with white wine but a decrease of 59% in those with red wine. The protective effect of red wine on platelets could be reproduced by tannins (procyanidins) extracted from grape seeds or red wine and added to 6% ethanol, but not by glycerol or wine without alcohol. That was related to inhibition of the alcohol-induced lipid peroxidation as shown by the lowering of conjugated dienes, lipid peroxides, and the increase in vitamin E in plasma. Owing to tannins, the platelets of rats drinking red wine did not exhibit the rebound effect observed hours after alcohol drinking, eventually associated with sudden death and stroke in humans.

Effect of bit wear on hammer drill handle vibration and productivity.

PubMed

Antonucci, Andrea; Barr, Alan; Martin, Bernard; Rempel, David

2017-08-01

The use of large electric hammer drills exposes construction workers to high levels of hand vibration that may lead to hand-arm vibration syndrome and other musculoskeletal disorders. The aim of this laboratory study was to investigate the effect of bit wear on drill handle vibration and drilling productivity (e.g., drilling time per hole). A laboratory test bench system was used with an 8.3 kg electric hammer drill and 1.9 cm concrete bit (a typical drill and bit used in commercial construction). The system automatically advanced the active drill into aged concrete block under feed force control to a depth of 7.6 cm while handle vibration was measured according to ISO standards (ISO 5349 and 28927). Bits were worn to 4 levels by consecutive hole drilling to 4 cumulative drilling depths: 0, 1,900, 5,700, and 7,600 cm. Z-axis handle vibration increased significantly (p<0.05) from 4.8 to 5.1 m/s 2 (ISO weighted) and from 42.7-47.6 m/s 2 (unweighted) when comparing a new bit to a bit worn to 1,900 cm of cumulative drilling depth. Handle vibration did not increase further with bits worn more than 1900 cm of cumulative drilling depth. Neither x- nor y-axis handle vibration was effected by bit wear. The time to drill a hole increased by 58% for the bit with 5,700 cm of cumulative drilling depth compared to a new bit. Bit wear led to a small but significant increase in both ISO weighted and unweighted z-axis handle vibration. Perhaps more important, bit wear had a large effect on productivity. The effect on productivity will influence a worker's allowable daily drilling time if exposure to drill handle vibration is near the ACGIH Threshold Limit Value. [1] Construction contractors should implement a bit replacement program based on these findings.

Short communication: human immunodeficiency virus rebound in blood and seminal plasma following discontinuation of antiretroviral therapy.

PubMed

Costiniuk, Cecilia T; Kovacs, Colin; Routy, Jean-Pierre; Singer, Joel; Gurunathan, Sanjay; Sekaly, Rafick-Pierre; Angel, Jonathan B

2013-02-01

Although there is discordance between human immunodeficiency virus (HIV) blood plasma and seminal plasma viral loads (VL), little is known about the dynamics of VL rebound in these compartments upon discontinuation of highly active antiretroviral therapy (HAART). Therefore, we sought to examine the relationship between blood and semen VL rebound after discontinuation of HAART. Participants in this substudy were men enrolled from two centers of a multicenter, placebo-controlled randomized trial of HIV therapeutic vaccination using ALVAC with or without Remune. With at least 2 years of sustained virologic suppression and following a 20-week vaccination course, subjects underwent structured HAART interruption. Fourteen men provided semen samples. Seven to 12 weeks after HAART interruption, all 14 men had detectable blood VLs whereas 8 of 14 had detectable seminal VLs. There was a significant correlation between blood and seminal VLs (Spearman r=0.58, p=0.03) at the time of semen collection. An earlier time to detectable blood VL after HAART interruption was associated with higher seminal VL (Spearman r=-0.64, p=0.02). These findings support the compartmentalization of HIV and underscore the importance of understanding the genital tract as an HIV reservoir in the quest to minimize HIV transmission.

Enlargement of basilar artery aneurysms following balloon occlusion--"water-hammer effect". Report of two cases.

PubMed

Kwan, E S; Heilman, C B; Shucart, W A; Klucznik, R P

1991-12-01

Two patients with distal basilar aneurysms were treated with intra-aneurysmal balloon occlusion. After apparently successful therapy, follow-up angiograms demonstrated aneurysm enlargement with balloon migration distally in the sac. Geometric mismatch between the base of the balloons and the aneurysm neck together with transmitted pulsation through the 2-hydroxyl-ethylmethacrylate (HEMA)-filled balloon directly contributed to aneurysm enlargement. In this report, the authors discuss the problems of progressive aneurysm enlargement due to a "water-hammer effect" and the possibility of hemorrhage following subtotal occlusion.

The degree of color change, rebound effect and sensitivity of bleached teeth associated with at-home and power bleaching techniques: A randomized clinical trial

PubMed Central

Moghadam, Fatemeh Velayati; Majidinia, Sara; Chasteen, Joseph; Ghavamnasiri, Marjaneh

2013-01-01

Aim: The purpose of the present randomized clinical trial was to evaluate the color change, rebound effect and sensitivity of at-home bleaching with 15% carbamide peroxide and power bleaching using 38% hydrogen peroxide. Materials and Methods: For bleaching techniques, 20 subjects were randomized in a split mouth design (at-home and power bleaching): In maxillary and mandibular anterior teeth (n = 20). Color was recorded before bleaching, immediately after bleaching, at 2 weeks, 1, 3 and 6 month intervals. Tooth sensitivity was recorded using the visual analog scale. The Mann-Whitney test was used to compare both groups regarding bleaching effectiveness (ΔE1), rebound effect (ΔE2) and color difference between the rebounded tooth color and unbleached teeth (ΔE3) while the Wilcoxon compared ΔE within each group. Distribution of sensitivity was evaluated using the Chi-square test (α =0.05). Results: There was no significant difference between groups regarding ΔE1 and ΔE3 (P > 0.05). Even though, ΔE2 showed no significant difference between groups after bleaching as well as at 2 week, 1 month and 3 month follow-up periods (P > 0.05). Although, significant difference was found in ΔE2 (P < 0.05 Mann-Whitney) between two methods after 6 months and a high degree of rebound effect was obtained with power bleaching. Within each group, there was no significant difference between ΔE1 and ΔE3 (P < 0.05 Wilcoxon). The distribution of sensitivity was identical with both techniques (P > 0.05). Conclusion: Bleaching techniques resulted in identical tooth whitening and post-operative sensitivity using both techniques, but faster color regression was found with power bleaching even though color regression to the baseline of the teeth in both groups was the same after 6 months. PMID:24932113

Measurement and interpretation of crustal deformation rates associated with postglacial rebound

NASA Technical Reports Server (NTRS)

Davis, James L.

1994-01-01

This project involves obtaining GPS measurements in Scandinavia and using the measurements to estimate the viscosity profile of the earth's mantle and to correct tide-gauge measurements for the rebound effect. We report on several aspects of this project. The DSGS was not scheduled to be reoccupied with DOSE receivers during the report period. The permanent network set up by Onsala Space Observatory continues to operate, and the data are being evaluated. An important technical advance we intend for this project is to use the full three dimensional site velocity information for inferring geophysical parameters. During the report period, two papers have been been accepted for publication in the Journal of Geophysical Research and will be published in April. Reprints of these papers are contained in the Appendix.

Energy based simulation of a Timoshenko beam in non-forced rotation. Influence of the piano hammer shank flexibility on the sound

NASA Astrophysics Data System (ADS)

Chabassier, Juliette; Duruflé, Marc

2014-12-01

A nonlinear model for a vibrating Timoshenko beam in non-forced unknown rotation is derived from the virtual work principle applied to a system of beam with mass at the end. The system represents a piano hammer shank coupled to a hammer head. An energy-based numerical scheme is then provided, obtained by non-classical approaches. A major difficulty for time discretization comes from the nonlinear behavior of the kinetic energy of the system. This new numerical scheme is then coupled to a global energy-preserving numerical solution for the whole piano. The obtained numerical simulations show that the pianistic touch clearly influences the spectrum of the piano sound of equally loud isolated notes. These differences do not come from a possible shock excitation on the structure, or from a changing impact point, or a “longitudinal rubbing motion” on the string, since neither of these features is modeled in our study.

Relationship of HIV Reservoir Characteristics with Immune Status and Viral Rebound Kinetics in an HIV Therapeutic Vaccine Study

PubMed Central

Li, Jonathan Z.; Heisey, Andrea; Ahmed, Hayat; Wang, Hongying; Zheng, Lu; Carrington, Mary; Wrin, Terri; Schooley, Robert T.; Lederman, Michael M.; Kuritzkes, Daniel R.

2014-01-01

Objectives To evaluate the impact of therapeutic HIV vaccination on the HIV reservoir, and assess the relationship of the viral reservoir with HIV-specific immune status and viral rebound kinetics. Design Retrospective analysis of ACTG A5197, a randomized, placebo-controlled trial of a therapeutic rAd5 HIV-1 gag vaccine. Methods Participants received vaccine/placebo at weeks 0, 4, and 26 prior to a 16-week analytic treatment interruption (ATI) at week 38. Cell-associated HIV-1 RNA and DNA (CA-RNA and CA-DNA) and HIV-1 residual viremia (RV) were quantified at weeks 0, 8, and 38. HIV-specific CD4+/CD8+ activity were assessed by an intracellular cytokine staining assay. Results At study entry, CA-RNA and CA-DNA levels were correlated inversely with the numbers of HIV-specific CD4+ interferon-γ-producing cells (CA-RNA: r = −0.23, P=0.03 and CA-DNA: r = −0.28, P<0.01, N=93). Therapeutic HIV vaccination induced HIV-specific CD4+ activity, but did not significantly affect levels of CA-RNA or CA-DNA. Vaccine recipients with undetectable RV at week 8 had higher frequencies of HIV-specific CD4+ and CD8+ interferon-γ-producing cells (undetectable versus detectable RV: 277 versus 161 CD4+ cells/106 lymphocytes, P=0.03 and 1326 versus 669 CD8+ cells/106 lymphocytes, P=0.04). Pre-ATI CA-RNA and CA-DNA were associated with post-ATI plasma HIV set point (CA-RNA: r = 0.51, P<0.01 and CA-DNA: r = 0.47, P<0.01). Conclusions Vaccine-induced T-cell responses were associated with a modest transient effect on RV, but more potent immune responses and/or combination treatment with latency-reversing agents are needed to reduce the HIV reservoir. HIV reservoir measures may act as biomarkers of post-ATI viral rebound kinetics. PMID:25254301

Hammering Yucca Flat, Part One: P-Wave Velocity

NASA Astrophysics Data System (ADS)

Tang, D. G.; Abbott, R. E.; Preston, L. A.; Hampshire, J. B., II

2015-12-01

Explosion-source phenomenology is best studied when competing signals (such as instrument, site, and propagation effects), are well understood. The second phase of the Source Physics Experiments (SPE), is moving from granite geology to alluvium geology at Yucca Flat, Nevada National Security Site. To improve subsurface characterization of Yucca Flat (and therefore better understand propagation and site effects), an active-source seismic survey was conducted using a novel 13,000-kg impulsive hammer source. The source points, spaced 200 m apart, covered a N-S transect spanning 18 km. Three component, 2-Hz geophones were used to record useable signals out to 10 km. We inverted for P-wave velocity by computing travel times using a finite-difference 3D eikonal solver, and then compared that to the picked travel times using a linearized iterative inversion scheme. Preliminary results from traditional reflection processing methods are also presented. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Modulation of post-movement beta rebound by contraction force and rate of force development.

PubMed

Fry, Adam; Mullinger, Karen J; O'Neill, George C; Barratt, Eleanor L; Morris, Peter G; Bauer, Markus; Folland, Jonathan P; Brookes, Matthew J

2016-07-01

Movement induced modulation of the beta rhythm is one of the most robust neural oscillatory phenomena in the brain. In the preparation and execution phases of movement, a loss in beta amplitude is observed [movement related beta decrease (MRBD)]. This is followed by a rebound above baseline on movement cessation [post movement beta rebound (PMBR)]. These effects have been measured widely, and recent work suggests that they may have significant importance. Specifically, they have potential to form the basis of biomarkers for disease, and have been used in neuroscience applications ranging from brain computer interfaces to markers of neural plasticity. However, despite the robust nature of both MRBD and PMBR, the phenomena themselves are poorly understood. In this study, we characterise MRBD and PMBR during a carefully controlled isometric wrist flexion paradigm, isolating two fundamental movement parameters; force output, and the rate of force development (RFD). Our results show that neither altered force output nor RFD has a significant effect on MRBD. In contrast, PMBR was altered by both parameters. Higher force output results in greater PMBR amplitude, and greater RFD results in a PMBR which is higher in amplitude and shorter in duration. These findings demonstrate that careful control of movement parameters can systematically change PMBR. Further, for temporally protracted movements, the PMBR can be over 7 s in duration. This means accurate control of movement and judicious selection of paradigm parameters are critical in future clinical and basic neuroscientific studies of sensorimotor beta oscillations. Hum Brain Mapp 37:2493-2511, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Hypothenar hammer syndrome in sports.

PubMed

Müller, L P; Rudig, L; Kreitner, K F; Degreif, J

1996-01-01

Repetitive blunt trauma or single severe trauma to the hypothenar region may lead to traumatic thrombosis of the distal ulnar artery (hypothenar hammer syndrome, HHS). In the sports-related literature we found and analysed isolated cases attributed to injuries sustained during sporting activities such as baseball, badminton, handball, football, frisbee, softball, karate, weight-lifting and hockey. Further, we report the case of an amateur golf player with ischaemic symptoms of his left hand, where angiography revealed filling defects in the digital arteries associated with a corkscrew-like configuration of the distal ulnar artery. Magnetic resonance imaging (MRI) scan demonstrated, at the level of the hamulus ossis hamati, accessory fibres of m. palmaris brevis forming a sling around the ulnar artery. Treatment by resection of the thrombosed a. ulnaris segment and replacement with an autologous vein graft resulted in complete relief of symptoms. Histological sections revealed partially organized thrombi adherent to the intimal surface with fragmentation of the internal elastic membrane, indicating a traumatic genesis. As the mechanism of injury, we suspected intensive golf playing with the grip style and subsequent motions leading to pressure injury of the hypothenar area and the underlying ulnar artery. Contraction of the anomalous muscle belly may have additionally compressed the artery, slowing down the arterial flow and promoting thrombosis. In most reported cases including our own, it took a relatively long time until the cause of the disease as traumatic was found and accepted. The initial repetitive blunt or single severe trauma initiating the HHS can easily be overlooked or ignored. After intimal damage of a. ulnaris, the beginning of symptoms may be prolonged and mislead one into thinking the cause is a collagen or vasospastic disease.

Quest for postdialysis urea rebound-equilibrated Kt/V with only intradialytic urea samples.

PubMed

Jean, G; Charra, B; Chazot, C; Laurent, G

1999-09-01

Postdialysis urea rebound (PDUR) is a cause of Kt/V overestimation when it is calculated from predialysis and the immediate postdialysis blood urea collections. Measuring PDUR requires a 30- or 60-minute postdialysis sampling, which is inconvenient. Several methods had been devised for a reasonable approach to determine PDUR-equilibrated Kt/V in short dialysis without the need for a delayed sample. The aim of our study was to compare these different Kt/V methods during the longer eight-hour hemodialysis sessions, and to determine the optimum intradialytic urea sample time that fits best with PDUR. The study included 21 patients (mean age 71.9 years) who were hemodialyzed for 60+/-60 months at three times eight hours weekly, using bicarbonate dialysate and cellulosic membranes. Blood urea samples were obtained at onset, and then at 17, 33, 50, 66, 75, 80, 85, and 100% of the dialysis session times, after 30 seconds of low flow, and then at 60-minutes postdialysis. All patients had a meal during dialysis. We compared four different formulas of Kt/V [(a) Kt/V-Smye with a 33% dialysis time urea sample, (b) two-pool equilibrated eKt/V, (c) Kt/V-std (Daugirdas-2) obtained with an immediate postdialytic sample, and (d) the different intradialytic urea samples for Kt/V (50, 66, 75, 80, and 85% of dialysis time)] with the equilibrated 60-minute PDUR Kt/V (Kt/V-r-60) formula as the reference method. The mean PDUR was 17.2+/-9%, leading to an overestimation of Kt/V-std by 12.2%. Kt/V-r-60 was 1.68+/-0.34. Kt/V-std was 1.88+/-0.36 (Delta = 12.2+/-4.8%, r = 0.8). eKt/V was 1.77+/-0.3 (Delta = 5+/-5%, r = 0.96), and Kt/V-Smye was 1.79+/-0.47 (Delta = 5.2+/-14%, r = 0.9). The best time for the intradialytic sampling was 80% (that is, at 6 hr and 24 min). The Kt/V-80 was 1.64+/-0.3 and was best fitted with Kt/V-r-60 (Delta = -1.8+/-8%, r = 0.91). The mean intradialytic urea evolution showed a three-exponential rate, in discrepancy with the two-exponential rate theoretical model

Immunological biomarkers predict HIV-1 viral rebound after treatment interruption

PubMed Central

Hurst, Jacob; Hoffmann, Matthias; Pace, Matthew; Williams, James P.; Thornhill, John; Hamlyn, Elizabeth; Meyerowitz, Jodi; Willberg, Chris; Koelsch, Kersten K.; Robinson, Nicola; Brown, Helen; Fisher, Martin; Kinloch, Sabine; Cooper, David A.; Schechter, Mauro; Tambussi, Giuseppe; Fidler, Sarah; Babiker, Abdel; Weber, Jonathan; Kelleher, Anthony D.; Phillips, Rodney E.; Frater, John

2015-01-01

Treatment of HIV-1 infection with antiretroviral therapy (ART) in the weeks following transmission may induce a state of ‘post-treatment control' (PTC) in some patients, in whom viraemia remains undetectable when ART is stopped. Explaining PTC could help our understanding of the processes that maintain viral persistence. Here we show that immunological biomarkers can predict time to viral rebound after stopping ART by analysing data from a randomized study of primary HIV-1 infection incorporating a treatment interruption (TI) after 48 weeks of ART (the SPARTAC trial). T-cell exhaustion markers PD-1, Tim-3 and Lag-3 measured prior to ART strongly predict time to the return of viraemia. These data indicate that T-cell exhaustion markers may identify those latently infected cells with a higher proclivity to viral transcription. Our results may open new avenues for understanding the mechanisms underlying PTC, and eventually HIV-1 eradication. PMID:26449164

Quantum mechanical calculations suggest that lytic polysaccharide monooxygenases use a copper-oxyl, oxygen-rebound mechanism

PubMed Central

Kim, Seonah; Ståhlberg, Jerry; Sandgren, Mats; Paton, Robert S.; Beckham, Gregg T.

2014-01-01

Lytic polysaccharide monooxygenases (LPMOs) exhibit a mononuclear copper-containing active site and use dioxygen and a reducing agent to oxidatively cleave glycosidic linkages in polysaccharides. LPMOs represent a unique paradigm in carbohydrate turnover and exhibit synergy with hydrolytic enzymes in biomass depolymerization. To date, several features of copper binding to LPMOs have been elucidated, but the identity of the reactive oxygen species and the key steps in the oxidative mechanism have not been elucidated. Here, density functional theory calculations are used with an enzyme active site model to identify the reactive oxygen species and compare two hypothesized reaction pathways in LPMOs for hydrogen abstraction and polysaccharide hydroxylation; namely, a mechanism that employs a η1-superoxo intermediate, which abstracts a substrate hydrogen and a hydroperoxo species is responsible for substrate hydroxylation, and a mechanism wherein a copper-oxyl radical abstracts a hydrogen and subsequently hydroxylates the substrate via an oxygen-rebound mechanism. The results predict that oxygen binds end-on (η1) to copper, and that a copper-oxyl–mediated, oxygen-rebound mechanism is energetically preferred. The N-terminal histidine methylation is also examined, which is thought to modify the structure and reactivity of the enzyme. Density functional theory calculations suggest that this posttranslational modification has only a minor effect on the LPMO active site structure or reactivity for the examined steps. Overall, this study suggests the steps in the LPMO mechanism for oxidative cleavage of glycosidic bonds. PMID:24344312

Measurement and Interpretation of Crustal Deformation Rates Associated with Postglacial Rebound

NASA Technical Reports Server (NTRS)

Davis, James L.

1993-01-01

This project involves obtaining GPS measurements in Scandinavia, and using the measurements to estimate the viscosity profile of the Earth's mantle and to correct tide-gauge measurements for the rebound effect. Below, we report on several aspects of this project. The DSGS was occupied in August 1993. This campaign also inaugurated SWEPOS, the Swedish permanent GPS network. Initial results are presented in Johansson et al., a copy of which is contained in Appendix A. An important technical advance we intend for this project is to use the full three dimensional site velocity information for inferring geophysical parameters. To this end, we have investigated using VLBI determined baseline length rates in North America to constraining proposed combinations of ice history and earth rheology, and presented this work in Mitrovica et al., a copy of which is contained in Appendix B.

Renewable energy rebound effect?: Estimating the impact of state renewable energy financial incentives on residential electricity consumption

NASA Astrophysics Data System (ADS)

Stephenson, Beth A.

Climate change is a well-documented phenomenon. If left unchecked greenhouse gas emissions will continue global surface warming, likely leading to severe and irreversible impacts. Generating renewable energy has become an increasingly salient topic in energy policy as it may mitigate the impact of climate change. State renewable energy financial incentives have been in place since the mid-1970s in some states and over 40 states have adopted one or more incentives at some point since then. Using multivariate linear and fixed effects regression for the years 2002 through 2012, I estimate the relationship between state renewable energy financial incentives and residential electricity consumption, along with the associated policy implications. My hypothesis is that a renewable energy rebound effect is present; therefore, states with renewable energy financial incentives have a higher rate of residential electricity consumption. I find a renewable energy rebound effect is present in varying degrees for each model, but the results do not definitively indicate how particular incentives influence consumer behavior. States should use caution when adopting and keeping renewable energy financial incentives as this may increase consumption in the short-term. The long-term impact is unclear, making it worthwhile for policymakers to continue studying the potential for renewable energy financial incentives to alter consumer behavior.

Testing the Rebound Peer Review Concept

PubMed Central

Choi, Augustine M.K.

2013-01-01

Abstract This invited editorial addresses the rescue of the article by Skrzypek et al. “Interplay between heme oxygenase-1 and miR-378 affects non-small cell lung carcinoma growth, vascularization, and metastasis.” The work was rejected by the standard peer review system and subsequently rescued by the Rebound Peer Review (RPR) mechanism offered by Antioxidants and Redox Signaling (Antioxid Redox Signal 16: 293–296, 2012). The reviewers who openly rescued the article were James F. George, Justin C. Mason, Mahin D. Maines, and Yasufumi Sato. The initial article was a de novo resubmission of a previously rejected article, which was then reviewed by six reviewers. The reviewers raised substantial scientific concerns, including questions pertaining to the specificity of the findings, quality of the presentation, and other technical concerns; the editor returned a decision of reject. The authors voluntarily chose to exercise the option to rescue the article utilizing the RPR system, where the authors found qualified reviewers who were willing to advocate for acceptance with scientific reasoning. The open reviewers felt that the scientific and technical concerns raised by the reviewers were outweighed by the strengths and novelty of the findings to justify acceptance. The RPR, in this case, was a “success” in that it rescued a rejected article. Despite this assessment, we question the necessity of open peer review as a means to overturn a peer review decision, with concerns for the larger-than-usual peer review process, and the voluntary relinquishing of editorial privilege and disclosure of reviewer identity. Antioxid. Redox Signal. 19, 639–643. PMID:23725371

Dynamic analysis of an SDOF helicopter model featuring skid landing gear and an MR damper by considering the rotor lift factor and a Bingham number

NASA Astrophysics Data System (ADS)

Saleh, Muftah; Sedaghati, Ramin; Bhat, Rama

2018-06-01

The present study addresses the performance of a skid landing gear (SLG) system of a rotorcraft impacting the ground at a vertical sink rate of up to 4.5 ms‑1. The impact attitude is assumed to be level as per chapter 527 of the Airworthiness Manual of Transport Canada Civil Aviation and part 27 of the Federal Aviation Regulations of the US Federal Aviation Administration. A single degree of freedom helicopter model is investigated under different values of rotor lift factor, L. In this study, three SLG versions are evaluated: (a) standalone conventional SLG; (b) SLG equipped with a passive viscous damper; and (c) SLG incorporated a magnetorheological energy absorber (MREA). The non-dimensional solutions of the helicopter models show that the two former SLG systems suffer adaptability issues with variations in the impact velocity and the rotor lift factor. Therefore, the alternative successful choice is to employ the MREA. Two different optimum Bingham numbers for compression and rebound strokes are defined. A new chart, called the optimum Bingham number versus rotor lift factor ‘B{i}o-L’, is introduced in this study to correlate the optimum Bingham numbers to the variation in the rotor lift factor and to provide more accessibility from the perspective of control design. The chart shows that the optimum Bingham number for the compression stroke is inversely linearly proportional to the increase in the rotor lift factor. This alleviates the impact force on the system and reduces the amount of magnetorheological yield force that would be generated. On the contrary, the optimum Bingham number for the rebound stroke is found to be directly linearly proportional to the rotor lift factor. This ensures controllable attenuation of the restoring force of the linear spring element. This idea can be exploited to generate charts for different landing attitudes and sink rates. In this article, the response of the helicopter equipped with the conventional undamped, damped

Application of image processing technology to problems in manuscript encapsulation. [Codex Hammer

NASA Technical Reports Server (NTRS)

Glackin, D. L.; Korsmo, E. P.

1983-01-01

The long term effects of encapsulation individual sheets of the Codex Hammer were investigated. The manuscript was simulated with similar sheets of paper which were photographed under repeatable raking light conditions to enhance their surface texture, encapsulated in plexiglas, cycled in an environmental test chamber, and rephotographed at selected intervals. The film images were digitized, contrast enhanced, geometrically registered, and apodized. An FFT analysis of a control sheet and two experimental sheets indicates no micro-burnishing, but reveals that the ""mesoscale'' deformations with sizes 8mm are degrading monotonically, which is of no concern. Difference image analysis indicates that the sheets were increasingly stressed with time and that the plexiglas did not provide a sufficient environmental barrier under the simulation conditions. The relationship of these results to the Codex itself is to be determined.

Modulation of post‐movement beta rebound by contraction force and rate of force development

PubMed Central

Fry, Adam; Mullinger, Karen J.; O'Neill, George C.; Barratt, Eleanor L.; Morris, Peter G.; Bauer, Markus; Folland, Jonathan P.

2016-01-01

Abstract Movement induced modulation of the beta rhythm is one of the most robust neural oscillatory phenomena in the brain. In the preparation and execution phases of movement, a loss in beta amplitude is observed [movement related beta decrease (MRBD)]. This is followed by a rebound above baseline on movement cessation [post movement beta rebound (PMBR)]. These effects have been measured widely, and recent work suggests that they may have significant importance. Specifically, they have potential to form the basis of biomarkers for disease, and have been used in neuroscience applications ranging from brain computer interfaces to markers of neural plasticity. However, despite the robust nature of both MRBD and PMBR, the phenomena themselves are poorly understood. In this study, we characterise MRBD and PMBR during a carefully controlled isometric wrist flexion paradigm, isolating two fundamental movement parameters; force output, and the rate of force development (RFD). Our results show that neither altered force output nor RFD has a significant effect on MRBD. In contrast, PMBR was altered by both parameters. Higher force output results in greater PMBR amplitude, and greater RFD results in a PMBR which is higher in amplitude and shorter in duration. These findings demonstrate that careful control of movement parameters can systematically change PMBR. Further, for temporally protracted movements, the PMBR can be over 7 s in duration. This means accurate control of movement and judicious selection of paradigm parameters are critical in future clinical and basic neuroscientific studies of sensorimotor beta oscillations. Hum Brain Mapp 37:2493–2511, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc PMID:27061243

A 14-day regimen of esomeprazole 20 mg/day for frequent heartburn: durability of effects, symptomatic rebound, and treatment satisfaction.

PubMed

Peura, David; Le Moigne, Anne; Pollack, Charles; Nagy, Peter; Lind, Tore

2016-08-01

Esomeprazole 20 mg once daily has been shown to be effective for treating frequent heartburn over 14 days in subjects who are likely to self-treat with over-the-counter medications. These analyses were conducted to assess durability of effects and symptomatic rebound after cessation of treatment, treatment satisfaction, and rescue antacid use with esomeprazole 20 mg once daily for 14 days. Adults with frequent heartburn (≥ two days/week in the past four weeks) were randomly assigned to 14 days of double-blind treatment with esomeprazole 20 mg or placebo in two identical multicenter studies. All subjects entered a 1-week single-blind placebo follow-up period after treatment. The results of the primary efficacy endpoints were reported previously. The percentage of heartburn-free days during the 1-week follow-up, use of rescue antacids, and treatment satisfaction, measured with the Global Assessment Questions instrument, are described. The percentage of heartburn-free days was maintained during the 1-week follow-up period; the proportion was 43% among esomeprazole subjects in these studies, suggesting no evidence of symptomatic rebound. Rescue antacid use generally decreased compared with the run-in period in the 14-day treatment and 1-week follow-up periods. Significantly more subjects taking esomeprazole were "very satisfied" or "satisfied" with treatment versus placebo (Study 1: 78% vs. 63%, respectively, P = 0.0038; Study 2: 81% vs. 60%, respectively, P = 0.0002). Subjects who are likely to self-treat their frequent heartburn with over-the-counter medications reported satisfaction with esomeprazole 20 mg. Esomeprazole's treatment effect was maintained for ≥ one week after treatment ended, with no sign of symptomatic rebound. These trials were registered at ClinicalTrials.gov: NCT01370525; NCT01370538.

Rapid HIV RNA rebound after antiretroviral treatment interruption in persons durably suppressed in Fiebig I acute HIV infection.

PubMed

Colby, Donn J; Trautmann, Lydie; Pinyakorn, Suteeraporn; Leyre, Louise; Pagliuzza, Amélie; Kroon, Eugène; Rolland, Morgane; Takata, Hiroshi; Buranapraditkun, Supranee; Intasan, Jintana; Chomchey, Nitiya; Muir, Roshell; Haddad, Elias K; Tovanabutra, Sodsai; Ubolyam, Sasiwimol; Bolton, Diane L; Fullmer, Brandie A; Gorelick, Robert J; Fox, Lawrence; Crowell, Trevor A; Trichavaroj, Rapee; O'Connell, Robert; Chomont, Nicolas; Kim, Jerome H; Michael, Nelson L; Robb, Merlin L; Phanuphak, Nittaya; Ananworanich, Jintanat

2018-06-11

Antiretroviral therapy during the earliest stage of acute HIV infection (Fiebig I) might minimize establishment of a latent HIV reservoir and thereby facilitate viremic control after analytical treatment interruption. We show that 8 participants, who initiated treatment during Fiebig I and were treated for a median of 2.8 years, all experienced rapid viral load rebound following analytical treatment interruption, indicating that additional strategies are required to control or eradicate HIV.

Non-destructive testing techniques for the forensic engineering investigation of reinforced concrete buildings.

PubMed

Hobbs, Brian; Tchoketch Kebir, Mohamed

2007-04-11

This study describes in detail the results of a laboratory investigation where the compressive strength of 150mm side-length cubes was evaluated. Non-destructive testing (NDT) was carried out using ultrasonic pulse velocity (UPV) and impact rebound hammer (IRH) techniques to establish a correlation with the compressive strengths of compression tests. To adapt the Schmidt hammer apparatus and the ultrasonic pulse velocity tester to the type of concrete used in Algeria, concrete mix proportions that are recommended by the Algerian code were chosen. The resulting correlation curve for each test is obtained by changing the level of compaction, water/cement ratio and concrete age of specimens. Unlike other works, the research highlights the significant effect of formwork material on surface hardness of concrete where two different mould materials for specimens were used (plastic and wood). A combined method for the above two tests, reveals an improvement in the strength estimation of concrete. The latter shows more improvement by including the concrete density. The resulting calibration curves for strength estimation were compared with others from previous published literature.

Agreement among Goldmann applanation tonometer, iCare, and Icare PRO rebound tonometers; non-contact tonometer; and Tonopen XL in healthy elderly subjects.

PubMed

Kato, Yoshitake; Nakakura, Shunsuke; Matsuo, Naoko; Yoshitomi, Kayo; Handa, Marina; Tabuchi, Hitoshi; Kiuchi, Yoshiaki

2018-04-01

To evaluate the inter-device agreement among the Goldmann applanation tonometer (GAT), iCare and Icare PRO rebound tonometers, non-contact tonometer (NCT), and Tonopen XL tonometer. Sixty healthy elderly subjects were enrolled. The intraocular pressure (IOP) in each subject's right eye was measured thrice using each of the five tonometers. Intra-device agreement was evaluated by calculating intraclass correlation coefficients (ICCs). Inter-device agreement was evaluated by ICC and Bland-Altman analyses. ICCs for intra-device agreement for each tonometer were >0.8. IOP as measured by iCare (mean ± SD, 11.6 ± 2.5 mmHg) was significantly lower (p < 0.05) than that measured by GAT (14.0 ± 2.8 mmHg), NCT (13.6 ± 2.5 mmHg), Tonopen XL (13.7 ± 4.1 mmHg), and Icare PRO (12.6 ± 2.2 mmHg; Bonferroni test). There was no significant difference in mean IOP among GAT, NCT, and Tonopen XL. Regarding inter-device agreement, ICC was lower between Tonopen XL and other tonometers (all ICCs < 0.4). However, ICCs of GAT, iCare, Icare PRO, and NCT showed good agreement (0.576-0.700). The Bland-Altman analysis revealed that the width of the 95% limits of agreement was larger between the Tonopen XL and the other tonometers ranged from 14.94 to 16.47 mmHg. Among the other tonometers, however, the widths of 95% limits of agreement ranged from 7.91 to 9.24 mmHg. There was good inter-device agreement among GAT, rebound tonometers, and NCT. Tonopen XL shows the worst agreement with the other tonometers; therefore, we should pay attention to its' respective IOP. Japan Clinical Trials Register; number: UMIN000011544.

Plume splitting and rebounding in a high-intensity CO{sub 2} laser induced air plasma

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

Chen Anmin; Jiang Yuanfei; Liu Hang

2012-07-15

The dynamics of plasma plume formed by high-intensity CO{sub 2} laser induced breakdown of air at atmospheric pressure is investigated. The laser wavelength is 10.6 {mu}m. Measurements were made using 3 ns gated fast photography as well as space and time resolved optical emission spectroscopy. The behavior of the plasma plume was studied with a laser energy of 3 J and 10 J. The results show that the evolution of the plasma plume is very complicated. The splitting and rebounding of the plasma plume is observed to occur early in the plumes history.

Structural and Geophysical Characterization of Oklahoma Basement

NASA Astrophysics Data System (ADS)

Morgan, C.; Johnston, C. S.; Carpenter, B. M.; Reches, Z.

2017-12-01

Oklahoma has experienced a large increase in seismicity since 2009 that has been attributed to wastewater injection. Most earthquakes, including four M5+ earthquakes, nucleated at depths > 4 km, well within the pre-Cambrian crystalline basement, even though wastewater injection occurred almost exclusively in the sedimentary sequence above. To better understand the structural characteristics of the rhyolite and granite that makeup the midcontinent basement, we analyzed a 150 m long core recovered from a basement borehole (Shads 4) in Rogers County, NE Oklahoma. The analysis of the fracture network in the rhyolite core included measurements of fracture inclination, aperture, and density, the examination fracture surface features and fill minerology, as well as x-ray diffraction analysis of secondary mineralization. We also analyzed the highly fractured and faulted segments of the core with a portable gamma-ray detector, magnetometer, and rebound hammer. The preliminary analysis of the fractures within the rhyolite core showed: (1) Fracture density increasing with depth by a factor of 10, from 4 fractures/10m in the upper core segment to 40 fracture/10m at 150 m deeper. (2) The fractures are primarily sub-vertical, inclined 10-20° from the axis of the vertical core. (3) The secondary mineralization is dominated by calcite and epidote. (4) Fracture aperture ranges from 0.35 to 2.35mm based on the thickness of secondary filling. (5) About 8% of the examined fractures display slickenside striations. (6) Increases of elasticity (by rebound hammer) and gamma-ray emissions are systematically correlated with a decrease in magnetic susceptibility in core segments of high fracture density and/or faulting; this observation suggests diagenetic fracture re-mineralization.

Reliability of the Achilles tendon tap reflex evoked during stance using a pendulum hammer.

PubMed

Mildren, Robyn L; Zaback, Martin; Adkin, Allan L; Frank, James S; Bent, Leah R

2016-01-01

The tendon tap reflex (T-reflex) is often evoked in relaxed muscles to assess spinal reflex circuitry. Factors contributing to reflex excitability are modulated to accommodate specific postural demands. Thus, there is a need to be able to assess this reflex in a state where spinal reflex circuitry is engaged in maintaining posture. The aim of this study was to determine whether a pendulum hammer could provide controlled stimuli to the Achilles tendon and evoke reliable muscle responses during normal stance. A second aim was to establish appropriate stimulus parameters for experimental use. Fifteen healthy young adults stood on a forceplate while taps were applied to the Achilles tendon under conditions in which postural sway was constrained (by providing centre of pressure feedback) or unconstrained (no feedback) from an invariant release angle (50°). Twelve participants repeated this testing approximately six months later. Within one experimental session, tap force and T-reflex amplitude were found to be reliable regardless of whether postural sway was constrained (tap force ICC=0.982; T-reflex ICC=0.979) or unconstrained (tap force ICC=0.968; T-reflex ICC=0.964). T-reflex amplitude was also reliable between experimental sessions (constrained ICC=0.894; unconstrained ICC=0.890). When a T-reflex recruitment curve was constructed, optimal mid-range responses were observed using a 50° release angle. These results demonstrate that reliable Achilles T-reflexes can be evoked in standing participants without the need to constrain posture. The pendulum hammer provides a simple method to allow researchers and clinicians to gather information about reflex circuitry in a state where it is involved in postural control. Copyright © 2015 Elsevier B.V. All rights reserved.

A comparison of virological suppression and rebound between Indigenous and non-Indigenous persons initiating combination antiretroviral therapy in a multisite cohort of individuals living with HIV in Canada.

PubMed

Benoit, Anita C; Younger, Jaime; Beaver, Kerrigan; Jackson, Randy; Loutfy, Mona; Masching, Renée; Nobis, Tony; Nowgesic, Earl; O'Brien-Teengs, Doe; Whitebird, Wanda; Zoccole, Art; Hull, Mark; Jaworsky, Denise; Rachlis, Anita; Rourke, Sean; Burchell, Ann N; Cooper, Curtis; Hogg, Robert; Klein, Marina B; Machouf, Nima; Montaner, Julio; Tsoukas, Chris; Raboud, Janet

2017-01-01

This study compared time to virological suppression and rebound between Indigenous and non-Indigenous individuals living with HIV in Canada initiating combination antiretroviral therapy (cART). Data were from the Canadian Observational Cohort collaboration; eight studies of treatment-naive persons with HIV initiating cART after 1/1/2000. Fine and Gray models were used to estimate the effect of ethnicity on time to virological suppression (two consecutive viral loads [VLs] <50 copies/ml at least 3 months apart) after adjusting for the competing risk of death and time until virological rebound (two consecutive VLs >200 copies/ml at least 3 months apart) following suppression. Among 7,080 participants were 497 Indigenous persons of whom 413 (83%) were from British Columbia. The cumulative incidence of suppression 1 year after cART initiation was 54% for Indigenous persons, 77% for Caucasian and 80% for African, Caribbean or Black (ACB) persons. The cumulative incidence of rebound 1 year after suppression was 13% for Indigenous persons, 6% for Caucasian and 7% for ACB persons. Indigenous persons were less likely to achieve suppression than Caucasian participants (aHR=0.58, 95% CI 0.50, 0.68), but not more likely to experience rebound (aHR=1.03, 95% CI 0.84, 1.27) after adjusting for age, gender, injection drug use, men having sex with men status, province of residence, baseline VL and CD4 + T-cell count, antiretroviral class and year of cART initiation. Lower suppression rates among Indigenous persons suggest a need for targeted interventions to improve HIV health outcomes during the first year of treatment when suppression is usually achieved.

SIMPL: A Simplified Model-Based Program for the Analysis and Visualization of Groundwater Rebound in Abandoned Mines to Prevent Contamination of Water and Soils by Acid Mine Drainage

PubMed Central

Kim, Sung-Min

2018-01-01

Cessation of dewatering following underground mine closure typically results in groundwater rebound, because mine voids and surrounding strata undergo flooding up to the levels of the decant points, such as shafts and drifts. SIMPL (Simplified groundwater program In Mine workings using the Pipe equation and Lumped parameter model), a simplified lumped parameter model-based program for predicting groundwater levels in abandoned mines, is presented herein. The program comprises a simulation engine module, 3D visualization module, and graphical user interface, which aids data processing, analysis, and visualization of results. The 3D viewer facilitates effective visualization of the predicted groundwater level rebound phenomenon together with a topographic map, mine drift, goaf, and geological properties from borehole data. SIMPL is applied to data from the Dongwon coal mine and Dalsung copper mine in Korea, with strong similarities in simulated and observed results. By considering mine workings and interpond connections, SIMPL can thus be used to effectively analyze and visualize groundwater rebound. In addition, the predictions by SIMPL can be utilized to prevent the surrounding environment (water and soil) from being polluted by acid mine drainage. PMID:29747480

Predictors of viral suppression and rebound among HIV-positive men who have sex with men in a large multi-site Canadian cohort.

PubMed

Tanner, Zachary; Lachowsky, Nathan; Ding, Erin; Samji, Hasina; Hull, Mark; Cescon, Angela; Patterson, Sophie; Chia, Jason; Leslie, Alia; Raboud, Janet; Loutfy, Mona; Cooper, Curtis; Klein, Marina; Machouf, Nima; Tsoukas, Christos; Montaner, Julio; Hogg, Robert S

2016-10-21

Gay, bisexual and other men who have sex with men (MSM) are disproportionately affected by HIV in Canada. Combination antiretroviral therapy has been shown to dramatically decrease progression to AIDS, premature death and HIV transmission. However, there are no comprehensive data regarding combination antiretroviral therapy outcomes among this population. We sought to identify socio-demographic and clinical correlates of viral suppression and rebound. Our analysis included MSM participants in the Canadian Observational Cohort, a multi-site cohort of HIV-positive adults from Canada's three most populous provinces, aged ≥18 years who first initiated combination antiretroviral therapy between 2000 and 2011. We used accelerated failure time models to identify factors predicting time to suppression (2 measures <50 copies/mL ≥30 days apart) and subsequent rebound (2 measures >200 copies/mL ≥30 days apart). Of 2,858 participants, 2,448 (86 %) achieved viral suppression in a median time of 5 months (Q1-Q3: 3-7 months). Viral suppression was significantly associated with later calendar year of antiretroviral therapy initiation, no history of injection drug use, lower baseline viral load, being on an initial regimen consisting of non-nucleoside reverse-transcriptase inhibitors, and older age. Among those who suppressed, 295 (12 %) experienced viral rebound. This was associated with earlier calendar year of antiretroviral therapy initiation, injection drug use history, younger age, higher baseline CD4 cell count, and living in British Columbia. Further strategies are required to optimize combination antiretroviral therapy outcomes in men who have sex with men in Canada, specifically targeting younger MSM and those with a history of injection drug use.

First attempt to study rock glaciers in New Zealand using the Schmidt-hammer - framework and preliminary results

NASA Astrophysics Data System (ADS)

Winkler, Stefan; Lambiel, Christophe; Sattler, Katrin; Büche, Thomas; Springer, Johanna

2016-04-01

Although not uncommon within the dryer eastern parts of the Southern Alps, New Zealand, comparatively few previous studies have previously focused on rock glacier dynamics and spatial distribution. Neither investigations of their chronological constraints nor any studies on actual rock glacier velocities have yet been carried out. Rock glaciers and periglacial processes still largely constitute a largely unexplored albeit potentially valuable field of research in the Southern Alps. The high-altitude valley head of Irishman Stream in the Ben Ohau Range between Lakes Ohau and Pukaki, roughly 30 km southeast of the Main Divide, contains a few morphologically intact rock glaciers and some appear to be active features (Sattler et al. 2016). Previous work focusing on the Late-glacial and early Holocene moraines in the valley head below the rock glaciers (Kaplan et al. 2010) provided 10Be-ages that could be utilised as fixed points for SHD (Schmidt-hammer exposure-age dating). Apart from detailed Schmidt-hammer sampling on the Late-glacial and early Holocene moraines, two altitudinal transects from the toe to their apex have been measured in detail on selected rock glaciers. On each of the multiple ridges of the rock glacier surface three sites of 50 boulders have been sampled with one impact each by the hammer (an N-type electronic SilverSchmidt by Proceq). Apart from getting some age constraints of these periglacial features in comparison to the well-dated moraines, the Schmidt-hammer measurements also had the aim to provide some insight into their genetic development resulting in a quite complex morphology of the rock glaciers and partial interaction with some of the moraines. Both altitudinal transects reveal a clear and continuous trend of increasing means (i.e. less weathered/younger exposure ages) towards their apex. The values for the individual ridges show, however, a transitional character with adjacent ridges albeit the abovementioned trend not statistically

Adiposity rebound and the development of metabolic syndrome.

PubMed

Koyama, Satomi; Ichikawa, Go; Kojima, Megumi; Shimura, Naoto; Sairenchi, Toshimi; Arisaka, Osamu

2014-01-01

The age of adiposity rebound (AR) is defined as the time at which BMI starts to rise after infancy and is thought to be a marker of later obesity. To determine whether this age is related to future occurrence of metabolic syndrome, we investigated the relationship of the timing of AR with metabolic consequences at 12 years of age. A total of 271 children (147 boys and 124 girls) born in 1995 and 1996 were enrolled in the study. Serial measurements of BMI were conducted at the ages of 4 and 8 months and 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 years, based on which age of AR was calculated. Plasma lipids and blood pressure were measured at 12 years of age. An earlier AR (<4 years of age) was associated with a higher BMI (≥ 20) and a lipoprotein phenotype representative of insulin resistance. This phenotype consists of elevated triglycerides, apolipoprotein B, and atherogenic index and decreased high-density lipoprotein cholesterol in boys and elevated apolipoprotein B in girls at 12 years of age. The earlier AR was also related to elevated blood pressure in boys. This longitudinal population-based study indicates that children who exhibit AR at a younger age are predisposed to future development of metabolic syndrome. Therefore, monitoring of AR may be an effective method for the early identification of children at risk for metabolic syndrome.

Postglacial Rebound and Current Ice Loss Estimates from Space Geodesy: The New ICE-6G (VM5a) Global Model

NASA Astrophysics Data System (ADS)

Peltier, W. R.; Argus, D.; Drummond, R.; Moore, A. W.

2012-12-01

We compare, on a global basis, estimates of site velocity against predictions of the newly constructed postglacial rebound model ICE-6G (VM5a). This model is fit to observations of North American postglacial rebound thereby demonstrating that the ice sheet at last glacial maximum must have been, relative to ICE-5G,thinner in southern Manitoba, thinner near Yellowknife (northwest Territories), thicker in eastern and southern Quebec, and thicker along the British Columbia-Alberta border. The GPS based estimates of site velocity that we employ are more accurate than were previously available because they are based on GPS estimates of position as a function of time determined by incorporating satellite phase center variations [Desai et al. 2011]. These GPS estimates are constraining postglacial rebound in North America and Europe more tightly than ever before. In particular, given the high density of GPS sites in North America, and the fact that the velocity of the mass center (CM) of Earth is also more tightly constrained, the new model much more strongly constrains both the lateral extent of the proglacial forebulge and the rate at which this peripheral bulge (that was emplaced peripheral to the late Pleistocence Laurentia ice sheet) is presently collapsing. This fact proves to be important to the more accurate inference of the current rate of ice loss from both Greenland and Alaska based upon the time dependent gravity observations being provided by the GRACE satellite system. In West Antarctica we have also been able to significantly revise the previously prevalent ICE-5G deglaciation history so as to enable its predictions to be optimally consistent with GPS site velocities determined by connecting campaign WAGN measurements to those provided by observations from the permanent ANET sites. Ellsworth Land (south of the Antarctic peninsula), is observed to be rising at 6 ±3 mm/yr according to our latest analyses; the Ellsworth mountains themselves are observed to be

Color management with a hammer: the B-spline fitter

NASA Astrophysics Data System (ADS)

Bell, Ian E.; Liu, Bonny H. P.

2003-01-01

To paraphrase Abraham Maslow: If the only tool you have is a hammer, every problem looks like a nail. We have a B-spline fitter customized for 3D color data, and many problems in color management can be solved with this tool. Whereas color devices were once modeled with extensive measurement, look-up tables and trilinear interpolation, recent improvements in hardware have made B-spline models an affordable alternative. Such device characterizations require fewer color measurements than piecewise linear models, and have uses beyond simple interpolation. A B-spline fitter, for example, can act as a filter to remove noise from measurements, leaving a model with guaranteed smoothness. Inversion of the device model can then be carried out consistently and efficiently, as the spline model is well behaved and its derivatives easily computed. Spline-based algorithms also exist for gamut mapping, the composition of maps, and the extrapolation of a gamut. Trilinear interpolation---a degree-one spline---can still be used after nonlinear spline smoothing for high-speed evaluation with robust convergence. Using data from several color devices, this paper examines the use of B-splines as a generic tool for modeling devices and mapping one gamut to another, and concludes with applications to high-dimensional and spectral data.

Effect of different number of players and training regimes on physiological and technical demands of ball-drills in basketball.

PubMed

Conte, Daniele; Favero, Terence G; Niederhausen, Meike; Capranica, Laura; Tessitore, Antonio

2016-01-01

This study aimed to analyse the effects of two factors (number of players and training regimes) on players' physiological and technical demands in basketball ball-drills. Twenty-one young basketball players performed four different ball-drills (two levels for each factor). The number of players involved was 2vs2 and 4vs4, while ball-drill regimes were continuous and intermittent. Physiological demand was assessed using the percentage of maximal heart rate (%HRmax), Edwards' training load and rating of perceived exertion (RPE). Furthermore, the following technical actions were collected: dribbles, steals, rebounds, turnovers, passes (total, correct, wrong and % of correct pass) and shots (total, scored, missed and % of made shot). A 2 × 2 (number of players × regime) two-way ANOVA with repeated measures was applied for physiological parameters and technical actions. The 2vs2 condition showed higher %HRmax (P < 0.001), Edwards' training load (P < 0.001), RPE (P < 0.001), number of dribbles (P < 0.001), rebounds (P < 0.001), passes [total (P = 0.005) and correct (P = 0.005)] and shots [total (P < 0.001) scored (P < 0.001) and missed (P < 0.001)] than 4vs4. Moreover, the continuous regime revealed higher %HRmax (P < 0.001), Edwards' training load (P < 0.001), RPE (P = 0.006) and dribbles (P < 0.001) than the intermittent regime. This study showed that both number of players and regime are useful variables able to modify basketball ball-drills workload.

Water Touch-and-Bounce from a Soft Viscoelastic Substrate: Wetting, Dewetting, and Rebound on Bitumen.

PubMed

Lee, Jae Bong; Dos Santos, Salomé; Antonini, Carlo

2016-08-16

Understanding the interaction between liquids and deformable solid surfaces is a fascinating fundamental problem, in which interaction and coupling of capillary and viscoelastic effects, due to solid substrate deformation, give rise to complex wetting mechanisms. Here we investigated as a model case the behavior of water drops on two smooth bitumen substrates with different rheological properties, defined as hard and soft (with complex shear moduli in the order of 10(7) and 10(5) Pa, respectively, at 1 Hz), focusing both on wetting and on dewetting behavior. By means of classical quasi-static contact angle measurements and drop impact tests, we show that the water drop behavior can significantly change from the quasi-static to the dynamic regime on soft viscoelastic surfaces, with the transition being defined by the substrate rheological properties. As a result, we also show that on the hard substrate, where the elastic response is dominant under all investigated conditions, classical quasi-static contact angle measurements provide consistent results that can be used to predict the drop dynamic wetting behavior, such as drop deposition or rebound after impact, as typically observed for nondeformable substrates. Differently, on soft surfaces, the formation of wetting ridges did not allow to define uniquely the substrate intrinsic advancing and receding contact angles. In addition, despite showing a high adhesion to the soft surface in quasi-static measurements, the drop was surprisingly able to rebound and escape from the surface after impact, as it is typically observed for hydrophobic surfaces. These results highlight that measurements of wetting properties for viscoelastic substrates need to be critically used and that wetting behavior of a liquid on viscoelastic surfaces is a function of the characteristic time scales.

Revised simulation model does not predict rebound in gonorrhoea prevalence where core groups are treated in the presence of antimicrobial resistance.

PubMed

Trecker, Molly A; Hogan, Daniel J; Waldner, Cheryl L; Dillon, Jo-Anne R; Osgood, Nathaniel D

2015-06-01

To determine the effects of using discrete versus continuous quantities of people in a compartmental model examining the contribution of antimicrobial resistance (AMR) to rebound in the prevalence of gonorrhoea. A previously published transmission model was reconfigured to represent the occurrence of gonorrhoea in discrete persons, rather than allowing fractions of infected individuals during simulations. In the revised model, prevalence only rebounded under scenarios reproduced from the original paper when AMR occurrence was increased by 10(5) times. In such situations, treatment of high-risk individuals yielded outcomes very similar to those resulting from treatment of low-risk and intermediate-risk individuals. Otherwise, in contrast with the original model, prevalence was the lowest when the high-risk group was treated, supporting the current policy of targeting treatment to high-risk groups. Simulation models can be highly sensitive to structural features. Small differences in structure and parameters can substantially influence predicted outcomes and policy prescriptions, and must be carefully considered. 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.

Improving ATLAS grid site reliability with functional tests using HammerCloud

NASA Astrophysics Data System (ADS)

Elmsheuser, Johannes; Legger, Federica; Medrano Llamas, Ramon; Sciacca, Gianfranco; van der Ster, Dan

2012-12-01

With the exponential growth of LHC (Large Hadron Collider) data in 2011, and more coming in 2012, distributed computing has become the established way to analyse collider data. The ATLAS grid infrastructure includes almost 100 sites worldwide, ranging from large national computing centers to smaller university clusters. These facilities are used for data reconstruction and simulation, which are centrally managed by the ATLAS production system, and for distributed user analysis. To ensure the smooth operation of such a complex system, regular tests of all sites are necessary to validate the site capability of successfully executing user and production jobs. We report on the development, optimization and results of an automated functional testing suite using the HammerCloud framework. Functional tests are short lightweight applications covering typical user analysis and production schemes, which are periodically submitted to all ATLAS grid sites. Results from those tests are collected and used to evaluate site performances. Sites that fail or are unable to run the tests are automatically excluded from the PanDA brokerage system, therefore avoiding user or production jobs to be sent to problematic sites.

The Effect of Intraoperative Sounds of Saw and Hammer on Psychological Condition in Patients with Total Knee Arthroplasty: Prospective Randomized Study

PubMed Central

Kömürcü, Erkam; Kaymaz, Burak; Gölge, Umut Hatay; Nusran, Gürdal; Göksel, Ferdi; Şahin, Hasan; Ömür, Dilek; Hancı, Volkan

2015-01-01

Purpose. Surgical procedures are likely to be stressful for patients and their families. Total knee arthroplasty (TKA) is a major surgical procedure used in the treatment of osteoarthritis. During this procedure the sounds of the saw and hammer may irritate the patient and adversely affect mood. The present study examines the effect of these intraoperative sounds during TKA on postoperative mood and anxiety, by comparing two different anesthetic procedures. Methods. A total of 40 patients who underwent TKA for grade IV gonarthrosis participated in the study. Patients were randomly divided into two groups: 20 patients in the general anesthesia group and 20 patients in the spinal anesthesia group. Mood and anxiety changes were evaluated using the Profile of Mood States (POMS) and State-Trait Anxiety Inventory (STAI) instruments, respectively. Results. The postoperative POMS value in the spinal anesthesia group was definitively higher than the general anesthesia group, though the difference in preoperative and postoperative POMS and STAI scores between the two groups was not significant. Conclusion. It would seem that sounds of hammer and saw have no evident negative effect on patient's mood. Regional anesthesia is advisable for TKA patients and appropriate sedation can be administered during the operation if needed. PMID:25793222

Hypothenar Hammer Syndrome Caused by Recreational Sports Activities and Muscle Anomaly in the Wrist

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

Kreitner, Karl-Friedrich; Dueber, Christoph; Mueller, Lars-Peter

1996-09-15

A 34-year-old man with digital ischemia is reported. Angiography revealed thromboembolic occlusions of the proper digital arteries of the index, middle, and ring fingers and a tortuous ulnar artery in Guyon's canal. Though hypothenar hammer syndrome was suspected, there was no relevant occupational history. Magnetic resonance imaging and magnetic resonance angiography demonstrated an anomalous muscular sling around the ulnar artery immediately adjacent to the hook of the hamate. The ulnar artery showed mural thrombi in its tortuous segment. These findings were confirmed during operative exploration. After thrombectomy and embolectomy the involved segment of the ulnar artery was replaced by anmore » autologous vein graft. Postoperatively there was complete resolution of the symptoms. Only during convalescence did it become clear that the patient was a passionate golfer.« less

Yaruss, Coleman, and Hammer (2006): an exemplar of non-evidence-based practice in stuttering treatment.

PubMed

Ingham, Roger J

2007-07-01

This letter is a response to a recent report by J. S. Yaruss, C. Coleman, and D. Hammer (2006) that described a treatment program for preschool children who stutter. Problems with the Yaruss et al. study fall into four domains: (a) failure to provide clinicians with replicable procedures, (b) failure to collect valid and reliable speech performance data, (c) failure to control for predictable improvement in children who have been stuttering for less than 15 months, and (d) the advocacy of procedures for which there is no credible research evidence. The claims made for the efficacy of this treatment are problematic and essentially violate the principles of evidence-based practice as recommended by the American Speech-Language-Hearing Association (ASHA).

Gas hydrate dissociation off Svalbard induced by isostatic rebound rather than global warming.

PubMed

Wallmann, Klaus; Riedel, M; Hong, W L; Patton, H; Hubbard, A; Pape, T; Hsu, C W; Schmidt, C; Johnson, J E; Torres, M E; Andreassen, K; Berndt, C; Bohrmann, G

2018-01-08

Methane seepage from the upper continental slopes of Western Svalbard has previously been attributed to gas hydrate dissociation induced by anthropogenic warming of ambient bottom waters. Here we show that sediment cores drilled off Prins Karls Foreland contain freshwater from dissociating hydrates. However, our modeling indicates that the observed pore water freshening began around 8 ka BP when the rate of isostatic uplift outpaced eustatic sea-level rise. The resultant local shallowing and lowering of hydrostatic pressure forced gas hydrate dissociation and dissolved chloride depletions consistent with our geochemical analysis. Hence, we propose that hydrate dissociation was triggered by postglacial isostatic rebound rather than anthropogenic warming. Furthermore, we show that methane fluxes from dissociating hydrates were considerably smaller than present methane seepage rates implying that gas hydrates were not a major source of methane to the oceans, but rather acted as a dynamic seal, regulating methane release from deep geological reservoirs.

REM Sleep Rebound as an Adaptive Response to Stressful Situations

PubMed Central

Suchecki, Deborah; Tiba, Paula Ayako; Machado, Ricardo Borges

2011-01-01

Stress and sleep are related to each other in a bidirectional way. If on one hand poor or inadequate sleep exacerbates emotional, behavioral, and stress-related responses, on the other hand acute stress induces sleep rebound, most likely as a way to cope with the adverse stimuli. Chronic, as opposed to acute, stress impairs sleep and has been claimed to be one of the triggering factors of emotional-related sleep disorders, such as insomnia, depressive- and anxiety-disorders. These outcomes are dependent on individual psychobiological characteristics, conferring even more complexity to the stress-sleep relationship. Its neurobiology has only recently begun to be explored, through animal models, which are also valuable for the development of potential therapeutic agents and preventive actions. This review seeks to present data on the effects of stress on sleep and the different approaches used to study this relationship as well as possible neurobiological underpinnings and mechanisms involved. The results of numerous studies in humans and animals indicate that increased sleep, especially the rapid eye movement phase, following a stressful situation is an important adaptive behavior for recovery. However, this endogenous advantage appears to be impaired in human beings and rodent strains that exhibit high levels of anxiety and anxiety-like behavior. PMID:22485105

Effect of Number of Players and Maturity on Ball-Drills Training Load in Youth Basketball

PubMed Central

Conte, Daniele; Favero, Terence; Niederhausen, Meike; Capranica, Laura; Tessitore, Antonio

2017-01-01

This study aimed to assess the basketball ball-drills workload analyzing: (1) the effect of varying the number of players involved on physiological and technical demands; (2) the temporal changes in players’ responses across bouts; and (3) the relationship of players’ workload with their maturation status and training age. Twelve young male basketball players (mean ± SD; age 13.9 ± 0.7 years; height 1.76 ± 0.06 m; body mass 65.7 ± 12.5 kg; HRmax 202 ± 8 beat·min−1) completed three bouts of 4 min interspersed by 2 min of passive recovery of two vs. two and four vs. four ball-drills. The mean percentage of HRmax (%HRmax) and ratings of perceived exertion (RPE) were collected. Technical actions (TAs) (dribbles, passes, shots, interceptions, steals, rebounds, and turnovers) were calculated through notational analysis. Players’ genitalia development (GD) and pubic hair (PH) growth were assessed using Tanner scale. Results showed a higher %HRmax (p = 0.018), RPE (p = 0.042), dribbles (p = 0.007), shots (p = 0.003), and rebounds (p = 0.006) in two vs. two compared to four vs. four condition. Furthermore, a statistical difference was found for %HRmax (p = 0.005) and number of passes (p = 0.020) between bouts. In addition, no correlation between GD, PH, and training age with %HRmax, RPE, and TAs was found. These findings suggest that variations of the number of players involved affect ball-drills workload and that ball-drills training intensity varies across bouts. Finally, ball-drills elicit an adequate training stimulus, regardless of players’ maturation status and training age. PMID:29910363

Prolonged post-inhibitory rebound firing in the cerebellar nuclei mediated by group I mGluR potentiation of L-type Ca currents

PubMed Central

Zheng, Nan; Raman, Indira M.

2011-01-01

Neurons in the cerebellar nuclei fire at accelerated rates for prolonged periods after trains of synaptic inhibition that interrupt spontaneous firing. Both in vitro and in vivo, however, this prolonged rebound firing is favored by strong stimulation of afferents, suggesting that neurotransmitters other than GABA may contribute to the increased firing rates. Here, we tested whether metabotropic glutamate receptors modulate excitability of nuclear cells in cerebellar slices from mouse. In current clamp, the prolonged rebound firing rate after high-frequency synaptic stimulation was reduced by a variety of group I mGluR antagonists, including CPCCOEt (7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester), JNJ16259685 ((3,4-dihydro-2H-pyrano[2,3-b]quinolin-7-yl)-(cis-4-methoxycyclohexyl)-methanone)+MPEP, or 3-MATIDA (α-amino-5-carboxy-3-methyl-2-thiopheneacetic acid) +MPEP, as long as both mGluR1 and mGluR5 were blocked. This mGluR-dependent acceleration of firing was reduced but still evident when IPSPs were prevented by GABAA receptor antagonists. In voltage clamp, voltage ramps revealed a non-inactivating, low-voltage-activated, nimodipine-sensitive current that was enhanced by the selective group I mGluR agonist s-DHPG ((S)-3,5-dihydroxyphenylglycine). This putative L-type current also increased when mGluRs were activated by trains of evoked synaptic currents instead of direct application of agonist. In current clamp, blocking L-type Ca channels with the specific blocker nifedipine greatly reduced prolonged post-stimulus firing and occluded the effect of adding group I mGluR antagonists. Thus, potentiation of a low-voltage-activated L-type current by synaptically released glutamate accounted nearly fully for the mGluR-dependent acceleration of firing. Together, these data suggest that prolonged rebound firing in the cerebellar nuclei in vivo is most likely to occur when GABAA and mGluRs are simultaneously activated by concurrent excitation and

Fluid-structure interaction with pipe-wall viscoelasticity during water hammer

NASA Astrophysics Data System (ADS)

Keramat, A.; Tijsseling, A. S.; Hou, Q.; Ahmadi, A.

2012-01-01

Fluid-structure interaction (FSI) due to water hammer in a pipeline which has viscoelastic wall behaviour is studied. Appropriate governing equations are derived and numerically solved. In the numerical implementation of the hydraulic and structural equations, viscoelasticity is incorporated using the Kelvin-Voigt mechanical model. The equations are solved by two different approaches, namely the Method of Characteristics-Finite Element Method (MOC-FEM) and full MOC. In both approaches two important effects of FSI in fluid-filled pipes, namely Poisson and junction coupling, are taken into account. The study proposes a more comprehensive model for studying fluid transients in pipelines as compared to previous works, which take into account either FSI or viscoelasticity. To verify the proposed mathematical model and its numerical solutions, the following problems are investigated: axial vibration of a viscoelastic bar subjected to a step uniaxial loading, FSI in an elastic pipe, and hydraulic transients in a pressurised polyethylene pipe without FSI. The results of each case are checked with available exact and experimental results. Then, to study the simultaneous effects of FSI and viscoelasticity, which is the new element of the present research, one problem is solved by the two different numerical approaches. Both numerical methods give the same results, thus confirming the correctness of the solutions.

Cavitating flow during water hammer using a generalized interface vaporous cavitation model

NASA Astrophysics Data System (ADS)

Sadafi, Mohamadhosein; Riasi, Alireza; Nourbakhsh, Seyed Ahmad

2012-10-01

In a transient flow simulation, column separation may occur when the calculated pressure head decreases to the saturated vapor pressure head in a computational grid. Abrupt valve closure or pump failure can result in a fast transient flow with column separation, potentially causing problems such as pipe failure, hydraulic equipment damage, cavitation or corrosion. This paper reports a numerical study of water hammer with column separation in a simple reservoir-pipeline-valve system and pumping station. The governing equations for two-phase transient flow in pipes are solved based on the method of characteristics (MOC) using a generalized interface vaporous cavitating model (GIVCM). The numerical results were compared with the experimental data for validation purposes, and the comparison indicated that the GIVCM describes the experimental results more accurately than the discrete vapor cavity model (DVCM). In particular, the GIVCM correlated better with the experimental data than the DVCM in terms of timing and pressure magnitude. The effects of geometric and hydraulic parameters on flow behavior in a pumping station with column separation were also investigated in this study.

Development of size reduction equations for calculating power input for grinding pine wood chips using hammer mill

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

Naimi, Ladan J.; Collard, Flavien; Bi, Xiaotao

Size reduction is an unavoidable operation for preparing biomass for biofuels and bioproduct conversion. Yet, there is considerable uncertainty in power input requirement and the uniformity of ground biomass. Considerable gains are possible if the required power input for a size reduction ratio is estimated accurately. In this research three well-known mechanistic equations attributed to Rittinger, Kick, and Bond available for predicting energy input for grinding pine wood chips were tested against experimental grinding data. Prior to testing, samples of pine wood chips were conditioned to 11.7% wb, moisture content. The wood chips were successively ground in a hammer millmore » using screen sizes of 25.4 mm, 10 mm, 6.4 mm, and 3.2 mm. The input power and the flow of material into the grinder were recorded continuously. The recorded power input vs. mean particle size showed that the Rittinger equation had the best fit to the experimental data. The ground particle sizes were 4 to 7 times smaller than the size of installed screen. Geometric mean size of particles were calculated using two methods (1) Tyler sieves and using particle size analysis and (2) Sauter mean diameter calculated from the ratio of volume to surface that were estimated from measured length and width. The two mean diameters agreed well, pointing to the fact that either mechanical sieving or particle imaging can be used to characterize particle size. In conclusion, specific energy input to the hammer mill increased from 1.4 kWh t –1 (5.2 J g –1) for large 25.1-mm screen to 25 kWh t –1 (90.4 J g –1) for small 3.2-mm screen.« less

Development of size reduction equations for calculating power input for grinding pine wood chips using hammer mill

DOE PAGES

Naimi, Ladan J.; Collard, Flavien; Bi, Xiaotao; ...

2016-01-05

Size reduction is an unavoidable operation for preparing biomass for biofuels and bioproduct conversion. Yet, there is considerable uncertainty in power input requirement and the uniformity of ground biomass. Considerable gains are possible if the required power input for a size reduction ratio is estimated accurately. In this research three well-known mechanistic equations attributed to Rittinger, Kick, and Bond available for predicting energy input for grinding pine wood chips were tested against experimental grinding data. Prior to testing, samples of pine wood chips were conditioned to 11.7% wb, moisture content. The wood chips were successively ground in a hammer millmore » using screen sizes of 25.4 mm, 10 mm, 6.4 mm, and 3.2 mm. The input power and the flow of material into the grinder were recorded continuously. The recorded power input vs. mean particle size showed that the Rittinger equation had the best fit to the experimental data. The ground particle sizes were 4 to 7 times smaller than the size of installed screen. Geometric mean size of particles were calculated using two methods (1) Tyler sieves and using particle size analysis and (2) Sauter mean diameter calculated from the ratio of volume to surface that were estimated from measured length and width. The two mean diameters agreed well, pointing to the fact that either mechanical sieving or particle imaging can be used to characterize particle size. In conclusion, specific energy input to the hammer mill increased from 1.4 kWh t –1 (5.2 J g –1) for large 25.1-mm screen to 25 kWh t –1 (90.4 J g –1) for small 3.2-mm screen.« less

Dynamics of sonoluminescing bubbles within a liquid hammer device.

PubMed

Urteaga, Raúl; García-Martínez, Pablo Luis; Bonetto, Fabián J

2009-01-01

We studied the dynamics of a single sonoluminescing bubble (SBSL) in a liquid hammer device. In particular, we investigated the phosphoric acid-xenon system, in which pulses up to four orders of magnitude brighter than SBSL in water systems (about 10;{12} photons per pulse) have been previously reported [Chakravarty, Phys. Rev. E 69, 066317 (2004)]. We used stroboscopic photography and a Mie scattering technique in order to measure the radius evolution of the bubbles. Under adequate conditions we may position a bubble at the bottom of the tube (cavity) and a second bubble trapped at the middle of the tube (upper bubble). During its collapse, the cavity produces the compression of the liquid column. This compression drives impulsively the dynamics of the upper bubble. Our measurements reveal that the observed light emissions produced by the upper bubble are generated at its second collapse. We employed a simple numerical model to investigate the conditions that occur during the upper bubble collapse. We found good agreement between numerical and experimental values for the light intensity (fluence) and light pulse widths. Results from the model show that the light emission is increased mainly due to an increase in noble gas ambient radius and not because the maximum temperature increases. Even for the brightest pulses obtained ( 2x10;{13} photons, about 20W of peak power) the maximum temperatures computed for the upper bubble are always lower than 20000K .

Hypothenar hammer syndrome from ice hockey stick-handling.

PubMed

Zayed, Mohamed A; McDonald, Joey; Tittley, Jacques G

2013-11-01

Ulnar artery thrombosis and hypothenar hammer syndrome are rare vascular complications that could potentially occur with repeated blows or trauma to the hand. Although initially reported as an occupational hazard among laborers and craftsmen, it has been observed more recently among recreationalists and athletes. Until now, it has never been reported as a complication in ice hockey players. In this case report, a 26-year-old Canadian professional ice hockey player presented with acute dominant right hand paleness, coolness, and pain with hand use. The patient used a wooden hockey stick with a large knob of tape at the end of the handle, which he regularly gripped in the palm of his right hand to help with face-offs and general stick-handling. Sonographic evaluation demonstrated no arterial flow in the distal right ulnar artery distribution, and ulnar artery occlusion with no aneurysmal degeneration was confirmed by magnetic resonance angiogram. Intraarterial thrombolytic therapy was initiated, and subsequent serial angiograms demonstrated significant improvement in distal ulnar artery flow as well as recanalization of right hand deep palmar arch and digital arteries. The patient's symptoms resolved, and he was maintained on therapeutic anticoagulation for 3 months prior to returning to playing ice hockey professionally, but with a padded glove and no tape knob at the handle tip. This case highlights a unique presentation of hockey stick-handling causing ulnar artery thrombosis that was likely from repeated palmar hypothenar trauma. Appropriate diagnostic imaging, early intraarterial thrombolysis, and postoperative surveillance and follow-up were crucial for the successful outcome in this patient. Copyright © 2013 Elsevier Inc. All rights reserved.

Age at adiposity rebound and body mass index trajectory from early childhood to adolescence; differences by breastfeeding and maternal immigration background.

PubMed

Besharat Pour, M; Bergström, A; Bottai, M; Magnusson, J; Kull, I; Moradi, T

2017-02-01

This paper aims to assess association between breastfeeding and maternal immigration background and body mass index development trajectories from age 2 to 16 years. A cohort of children born in Stockholm during 1994 to 1996 was followed from age 2 to 16 years with repeated measurement of height and weight at eight time points (n = 2278). Children were categorized into groups by breastfeeding status during the first 6 months of life and maternal immigration background. Body mass index (BMI) trajectories and age at adiposity rebound were estimated using mixed-effects linear models. Body mass index trajectories were different by breastfeeding and maternal immigration status (P-value < 0.0001). Compared with exclusively breastfed counterparts, never/short breastfed children of Swedish mothers had a higher BMI trajectory, whereas never/short breastfed children of immigrant mothers followed a lower BMI trajectory. Ages at adiposity rebound were earlier for higher BMI trajectories regardless of maternal immigration background. Differences in BMI trajectories between offspring of immigrant and of Swedish mothers suggest a lack of beneficial association between breastfeeding and long-term BMI development among children of immigrant mothers. Given the relation between long-term BMI development and risk of overweight/obesity, these differences challenge the notion that exclusive breastfeeding is always beneficial for children's BMI development and subsequent risk of overweight/obesity. © 2016 World Obesity Federation.

Tools of Thor - more than a hammer: An overview of some analysis methods for turbulence investigation

NASA Astrophysics Data System (ADS)

Haaland, Stein; Vaivads, Andris; Eriksson, Elin

2016-04-01

In the old Norse mythology Thor was a hammer-wielding god associated with thunder and lightning. THOR is also an acronym for Turbulence Heating ObserveR - a planned space mission dedicated to stydy space plasma turbulence. Whereas the mythological Thor did most of his work with a single tool, Mjølnir - his hammer, the modern version of THOR is far more versatile. The proposed THOR spacecraft comes with a comprehensive package of instruments to explore the energy dissipation and particle energization taking place in turbulent plasma environments. This paper presents a more detailed investigation of some of the analysis methods listed in the submitted THOR proposal. To demonstrate the methods, we have used data from existing spacecraft missions like Cluster and MMS to examine and compare single-spacecraft and multi-spacecraft methods to establish proper frames. The presented analysis methods are based on fundamental plasma laws, such as conservation of mass, momentum and energy and do not require any triangulation or gradients based on multiple spacecraft. Our experience based on Cluster and MMS results show that a well equipped single spacecraft platform, like the proposed THOR mission, very often provides better and less ambiguous results that a constellation of many spacecraft with less capable instrumentation. Limitations in underlying assumptions, such as planarity and linearity, as well as non-optimal spacecraft separation and configurations often limit the possibility to utilize multi-spacecraft methods. We also investigate the role of time resolution and dynamical range of the measurements used in the methods. Since the particle instruments onboard THOR will have a much better time resolution than existing magnetospheric satellite missions, we infer that THOR will be far better suited to resolve time evolution in plasma structures. This is of particular importance in the solar wind and magnetosheat, where frame velocities can be very high. With a larger

Correlating P-wave Velocity with the Physico-Mechanical Properties of Different Rocks

NASA Astrophysics Data System (ADS)

Khandelwal, Manoj

2013-04-01

In mining and civil engineering projects, physico-mechanical properties of the rock affect both the project design and the construction operation. Determination of various physico-mechanical properties of rocks is expensive and time consuming, and sometimes it is very difficult to get cores to perform direct tests to evaluate the rock mass. The purpose of this work is to investigate the relationships between the different physico-mechanical properties of the various rock types with the P-wave velocity. Measurement of P-wave velocity is relatively cheap, non-destructive and easy to carry out. In this study, representative rock mass samples of igneous, sedimentary, and metamorphic rocks were collected from the different locations of India to obtain an empirical relation between P-wave velocity and uniaxial compressive strength, tensile strength, punch shear, density, slake durability index, Young's modulus, Poisson's ratio, impact strength index and Schmidt hammer rebound number. A very strong correlation was found between the P-wave velocity and different physico-mechanical properties of various rock types with very high coefficients of determination. To check the sensitivity of the empirical equations, Students t test was also performed, which confirmed the validity of the proposed correlations.

Validity of the Water Hammer Formula for Determining Regional Aortic Pulse Wave Velocity: Comparison of One-Point and Two-Point (Foot-to-Foot) Measurements Using a Multisensor Catheter in Human.

PubMed

Hanya, Shizuo

2013-01-01

Lack of high-fidelity simultaneous measurements of pressure and flow velocity in the aorta has impeded the direct validation of the water-hammer formula for estimating regional aortic pulse wave velocity (AO-PWV1) and has restricted the study of the change of beat-to-beat AO-PWV1 under varying physiological conditions in man. Aortic pulse wave velocity was derived using two methods in 15 normotensive subjects: 1) the conventional two-point (foot-to-foot) method (AO-PWV2) and 2) a one-point method (AO-PWV1) in which the pressure velocity-loop (PV-loop) was analyzed based on the water hammer formula using simultaneous measurements of flow velocity (Vm) and pressure (Pm) at the same site in the proximal aorta using a multisensor catheter. AO-PWV1 was calculated from the slope of the linear regression line between Pm and Vm where wave reflection (Pb) was at a minimum in early systole in the PV-loop using the water hammer formula, PWV1 = (Pm/Vm)/ρ, where ρ is the blood density. AO-PWV2 was calculated using the conventional two-point measurement method as the distance/traveling time of the wave between 2 sites for measuring P in the proximal aorta. Beat-to-beat alterations of AO-PWV1 in relationship to aortic pressure and linearity of the initial part of the PV-loop during a Valsalva maneuver were also assessed in one subject. The initial part of the loop became steeper in association with the beat-to-beat increase in diastolic pressure in phase 4 during the Valsalva maneuver. The linearity of the initial part of the PV-loop was maintained consistently during the maneuver. Flow velocity vs. pressure in the proximal aorta was highly linear during early systole, with Pearson's coefficients ranging from 0.9954 to 0.9998. The average values of AO-PWV1 and AO-PWV2 were 6.3 ± 1.2 and 6.7 ± 1.3 m/s, respectively. The regression line of AO-PWV1 on AO-PWV2 was y = 0.95x + 0.68 (r = 0.93, p <0.001). This study concluded that the water-hammer formula (one-point method) provides

Postglacial Rebound From Space Geodesy

NASA Astrophysics Data System (ADS)

Argus, D. F.; Peltier, W. R.

2005-12-01

To study the viscous response of the earth to the unloading of the late Pleistocene ice sheets and, to a lesser extent, the elastic response of the earth to current changes in ice sheet mass, we integrate geodetic observations from VLBI over 24 years, from SLR over 23 years, from DORIS over 12 years, and from GPS over 11 years. The excellent geodetic velocity solutions upon which this study are based are from Chopo Ma and Dan MacMillan (Goddard Space Flight Center), Michael Heflin (Jet Propulsion Laboratory), John Ries and Richard Eanes (Center for Space Research, University of Texas at Austin), and Pascal Willis (Institut Geogpraphique National and Jet Propulsion Laboratory). The rates of uplift and subsidence we determine, which in places differ significantly from published studies, are constraining postglacial rebound models like that of Peltier [1994], Peltier [1996], Milne [2001], and Peltier [2004]. We find the following: Yellowknife is rising at 5.7 ±1.8 mm/yr (95% confidence limits), showing [Peltier 2002, 2004], with complimentary ground observations of gravity [Lambert et al. 2001], that the western part of the Laurentide ice sheet was thicker during the Last Glacial Maximum than previously [Peltier 1994, 1996] believed. Onsala (Sweden) is rising at 2.4 ±1.3 mm/yr and Algonquin Park (Ontario) is rising at 2.3 ±1.4 mm/yr, constraining the positions of the margins of the Fennoscandian and Laurentide ice sheets during the Last Glacial Maximum. The eastern United States is falling at ~1 mm/yr, suggesting that the area around the ancient Laurentide ice sheet is subsiding more slowly than predicted by the model of Peltier [2004]. Western and central Europe are falling at ~0.5 mm/yr, suggesting that the area around the ancient Fennoscandian ice sheet is hardly subsiding at all, consistent with the model of Peltier [2004]. Kellyville (Greenland) is falling insignificantly at 1.1 ±4.3 mm/yr, not requiring current loading of the ice sheet [Wahr et al. 2002

The Effects of Bit Wear on Respirable Silica Dust, Noise and Productivity: A Hammer Drill Bench Study.

PubMed

Carty, Paul; Cooper, Michael R; Barr, Alan; Neitzel, Richard L; Balmes, John; Rempel, David

2017-07-01

Hammer drills are used extensively in commercial construction for drilling into concrete for tasks including rebar installation for structural upgrades and anchor bolt installation. This drilling task can expose workers to respirable silica dust and noise. The aim of this pilot study was to evaluate the effects of bit wear on respirable silica dust, noise, and drilling productivity. Test bits were worn to three states by drilling consecutive holes to different cumulative drilling depths: 0, 780, and 1560 cm. Each state of bit wear was evaluated by three trials (nine trials total). For each trial, an automated laboratory test bench system drilled 41 holes 1.3 cm diameter, and 10 cm deep into concrete block at a rate of one hole per minute using a commercially available hammer drill and masonry bits. During each trial, dust was continuously captured by two respirable and one inhalable sampling trains and noise was sampled with a noise dosimeter. The room was thoroughly cleaned between trials. When comparing results for the sharp (0 cm) versus dull bit (1560 cm), the mean respirable silica increased from 0.41 to 0.74 mg m-3 in sampler 1 (P = 0.012) and from 0.41 to 0.89 mg m-3 in sampler 2 (P = 0.024); levels above the NIOSH recommended exposure limit of 0.05 mg m-3. Likewise, mean noise levels increased from 112.8 to 114.4 dBA (P < 0.00001). Drilling productivity declined with increasing wear from 10.16 to 7.76 mm s-1 (P < 0.00001). Increasing bit wear was associated with increasing respirable silica dust and noise and reduced drilling productivity. The levels of dust and noise produced by these experimental conditions would require dust capture, hearing protection, and possibly respiratory protection. The findings support the adoption of a bit replacement program by construction contractors. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Skull wounds linked with blunt trauma (hammer example). A report of two depressed skull fractures--elements of biomechanical explanation.

PubMed

Delannoy, Yann; Becart, Anne; Colard, Thomas; Delille, Rémi; Tournel, Gilles; Hedouin, Valéry; Gosset, Didier

2012-09-01

The lesions of the skull following perforating traumas can create complex fractures. The blunt traumas can, according to the swiftness and the shape of the object used, create a depressed fracture. The authors describe through two clinical cases the lesional characteristic of the blunt traumas, perforating the skull using a hammer. In both cases the cranial lesions were very typical: they were geometrical, square shaped, of the same size than the tool (head and tip of the hammer). On the outer table of the skull, the edges of the wounds were sharp and regular. On the inner table, the edges of the wounds were beveled and irregular. The bony penetration in the depressed fracture results from a rupture of the outer table of the bone under tension, in periphery, by the bend of the bone to the impact (outbending) and then, from the inner table with comminuted bony fragmentation. Breeding on the fractures of the size and the shape of the blunt objects used is inconstant and differs, that it is the objects of flat surface or wide in opposition to those of small surface area. Fractures morphologies depend on one hand on these extrinsic factors and on the other hand, of intrinsic factors (structure of the bone). To identify them, we had previously conducted experimental work on cranial bone samples. The bone was submitted to a device for three-point bending. This work had shown properties of thickness and stiffness of the various areas of the vault. Our cases are consistent with these results and illustrate the variability of bone lesions according to region and mode of use of blunt weapons. Many studies have identified criteria for identification of the weapons and the assistance of digital and biomechanical models will be an invaluable contribution with this aim in the future. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

THE PHOENIX POPULATION: DEMOGRAPHIC CRISIS AND REBOUND IN CAMBODIA*

PubMed Central

HEUVELINE, PATRICK; POCH, BUNNAK

2014-01-01

The study of mortality crises provides an unusual and valuable perspective on the relationship between mortality and fertility changes, a relationship that has puzzled demographers for decades. In this article, we combine nationally representative survey and demographic-surveillance system data to study fertility trends around the time of the Khmer Rouge (KR) regime, under which 25% of the Cambodian population died. We present the first quantitative evidence to date that attests to a one-third decline of fertility during this regime, followed by a substantial “baby boom” after the fall of the KR. Further analyses reveal that the fertility rebound was produced not only by a two-year marriage bubble but also by a surge in marital fertility that remained for nearly a decade above its precrisis level. Our results illustrate the potential influence of mortality on fertility, which may be more difficult to identify for more gradual mortality declines. To the extent that until recently, Cambodian fertility appears to fit natural fertility patterns, our findings also reinforce meaning of this core paradigm of demographic analysis. In July 1978, a youth named Korb, bound hand and foot, arrived at a Pol Pot regime extermination camp. The local security chief, “Comrade Uncle An,” was handed the following note: Formerly this person was normal in character. Then, over about ten days, he went crazy. […] If many people come in, first he begins to whistle, and then he sings the following rhyme out loud: O! Khmers with black blood Now the eight-year Buddhist prophecy is being fulfilled. Vietnam is the elder brother Kampuchea is the younger. If we do not follow the Vietnamese as our elder brothers There will be nothing left of the Khmer this time but ashes.(Kiernan and Boua 1982:363) PMID:17583312

Water hammer effect in the spiral case and penstock of Francis turbines

NASA Astrophysics Data System (ADS)

Pepa, D.; Ursoniu, C.; Gillich, R. N.; Campian, C. V.

2017-01-01

Sudden pressure increases in the penstock or spiral case of a hydraulic turbine are the effect of sudden flow variation that occur during transient processes of type opening / closing or load rejection of the hydro unit. The consequence of the pressure rise in the spiral case and penstock is the water hammer phenomenon, whose effects can be devastating in some cases, up to breaking pipes and calamities produced in the area. This paper aims to analyze the method of calculation of the maximum pressure values that might occur in load rejection situations to a hydraulic turbine, in spiral case and in penstock, conditioned by the limiting of the values of the over speed and measures of limiting the increase in pressure in conjunction with limiting the increase in speed in these specific processes. As an example, we studied and analyzed the situation of a hydroelectric power plant equipped with a 7.8 MW Francis turbine without pressure regulator and the inflow surge. The results of analytical calculation overlaid on the experimental measurements performed during the performance tests of the hydro unit lead to the conclusion that the calculation algorithm proposed has been chosen correctly and the 2-stage closing law of the wicket gate promoted in this case is effective in such situations.

Chrna2-Martinotti Cells Synchronize Layer 5 Type A Pyramidal Cells via Rebound Excitation

PubMed Central

Leão, Richardson N.; Edwards, Steven J.

2017-01-01

Martinotti cells are the most prominent distal dendrite–targeting interneurons in the cortex, but their role in controlling pyramidal cell (PC) activity is largely unknown. Here, we show that the nicotinic acetylcholine receptor α2 subunit (Chrna2) specifically marks layer 5 (L5) Martinotti cells projecting to layer 1. Furthermore, we confirm that Chrna2-expressing Martinotti cells selectively target L5 thick-tufted type A PCs but not thin-tufted type B PCs. Using optogenetic activation and inhibition, we demonstrate how Chrna2-Martinotti cells robustly reset and synchronize type A PCs via slow rhythmic burst activity and rebound excitation. Moreover, using optical feedback inhibition, in which PC spikes controlled the firing of surrounding Chrna2-Martinotti cells, we found that neighboring PC spike trains became synchronized by Martinotti cell inhibition. Together, our results show that L5 Martinotti cells participate in defined cortical circuits and can synchronize PCs in a frequency-dependent manner. These findings suggest that Martinotti cells are pivotal for coordinated PC activity, which is involved in cortical information processing and cognitive control. PMID:28182735

Investigation and mitigation of condensation induced water hammer by stratified flow experiments

NASA Astrophysics Data System (ADS)

Kadakia, Hiral J.

This research primarily focuses on the possibility of using stratified flow in preventing an occurrence of condensation induced water hammer (CIWH) in horizontal pipe involving steam and subcooled water. A two-phase flow loop simulating the passive safety systems of an advanced light water reactor was constructed and a series of stratified flow experiments were carried out involving a system of subcooled water, saturated water, and steam. Special instruments were designed to measure steam flow rate and subcooled liquid velocity. These experiments showed that when flow field conditions meet certain criteria CIWH does occur. Flow conditions used in experiments were typically observed in passive safety systems of an advanced light water cooled reactor. This research summarizes a) literature research and other experimental data that signify an occurrence of CIWH, b) experiments in an effort to show an occurrence of CIWH and the ability to prevent CIWH, c) qualitative and quantitative results to underline the mechanism of CIWH, d) experiments that show CIWH can be prevented under certain conditions, and e) guidelines for the safe operating conditions. Based on initial experiment results it was observed that Bernoulli's effect can play an important role in wave formation and instability. A separate effect table top experiment was constructed with plexi-glass. A series of entrance effect tests and stratified experiments were carried out with different fluids to study wave formation and wave bridging. Special test series experiments were carried out to investigate the presence of a saturated layer. The effect of subcooled water and steam flow on wedge length and depth were recorded. These experiments helped create a model which calculates wedge and depth of wedge for a given condition of steam and subcooled water. A very good comparison between the experiment results and the model was obtained. These experiments also showed that the presence of saturated layer can mitigate

Validity of the Water Hammer Formula for Determining Regional Aortic Pulse Wave Velocity: Comparison of One-Point and Two-Point (Foot-to-Foot) Measurements Using a Multisensor Catheter in Human

PubMed Central

2013-01-01

Background: Lack of high-fidelity simultaneous measurements of pressure and flow velocity in the aorta has impeded the direct validation of the water-hammer formula for estimating regional aortic pulse wave velocity (AO-PWV1) and has restricted the study of the change of beat-to-beat AO-PWV1 under varying physiological conditions in man. Methods: Aortic pulse wave velocity was derived using two methods in 15 normotensive subjects: 1) the conventional two-point (foot-to-foot) method (AO-PWV2) and 2) a one-point method (AO-PWV1) in which the pressure velocity-loop (PV-loop) was analyzed based on the water hammer formula using simultaneous measurements of flow velocity (Vm) and pressure (Pm) at the same site in the proximal aorta using a multisensor catheter. AO-PWV1 was calculated from the slope of the linear regression line between Pm and Vm where wave reflection (Pb) was at a minimum in early systole in the PV-loop using the water hammer formula, PWV1 = (Pm/Vm)/ρ, where ρ is the blood density. AO-PWV2 was calculated using the conventional two-point measurement method as the distance/traveling time of the wave between 2 sites for measuring P in the proximal aorta. Beat-to-beat alterations of AO-PWV1 in relationship to aortic pressure and linearity of the initial part of the PV-loop during a Valsalva maneuver were also assessed in one subject. Results: The initial part of the loop became steeper in association with the beat-to-beat increase in diastolic pressure in phase 4 during the Valsalva maneuver. The linearity of the initial part of the PV-loop was maintained consistently during the maneuver. Flow velocity vs. pressure in the proximal aorta was highly linear during early systole, with Pearson’s coefficients ranging from 0.9954 to 0.9998. The average values of AO-PWV1 and AO-PWV2 were 6.3 ± 1.2 and 6.7 ± 1.3 m/s, respectively. The regression line of AO-PWV1 on AO-PWV2 was y = 0.95x + 0.68 (r = 0.93, p <0.001). Conclusion: This study concluded that the

Single Piezo-Actuator Rotary-Hammering Drill

NASA Technical Reports Server (NTRS)

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

2011-01-01

This innovation comprises a compact drill that uses low-axial preload, via vibrations, that fractures the rock under the bit kerf, and rotates the bit to remove the powdered cuttings while augmenting the rock fracture via shear forces. The vibrations fluidize the powered cuttings inside the flutes around the bit, reducing the friction with the auger surface. These combined actions reduce the consumed power and the heating of the drilled medium, helping to preserve the pristine content of the produced samples. The drill consists of an actuator that simultaneously impacts and rotates the bit by applying force and torque via a single piezoelectric stack actuator without the need for a gearbox or lever mechanism. This reduces the development/fabrication cost and complexity. The piezoelectric actuator impacts the surface and generates shear forces, fragmenting the drilled medium directly under the bit kerf by exceeding the tensile and/or shear strength of the struck surface. The percussive impact action of the actuator leads to penetration of the medium by producing a zone of finely crushed rock directly underneath the struck location. This fracturing process is highly enhanced by the shear forces from the rotation and twisting action. To remove the formed cuttings, the bit is constructed with an auger on its internal or external surface. One of the problems with pure hammering is that, as the teeth become embedded in the sample, the drilling efficiency drops unless the teeth are moved away from the specific footprint location. By rotating the teeth, they are moved to areas that were not fragmented, and thus the rock fracturing is enhanced via shear forces. The shear motion creates ripping or chiseling action to produce larger fragments to increase the drilling efficiency, and to reduce the required power. The actuator of the drill consists of a piezoelectric stack that vibrates the horn. The stack is compressed by a bolt between the backing and the horn in order to

Improved pump turbine transient behaviour prediction using a Thoma number-dependent hillchart model

NASA Astrophysics Data System (ADS)

Manderla, M.; Kiniger, K.; Koutnik, J.

2014-03-01

Water hammer phenomena are important issues for high head hydro power plants. Especially, if several reversible pump-turbines are connected to the same waterways there may be strong interactions between the hydraulic machines. The prediction and coverage of all relevant load cases is challenging and difficult using classical simulation models. On the basis of a recent pump-storage project, dynamic measurements motivate an improved modeling approach making use of the Thoma number dependency of the actual turbine behaviour. The proposed approach is validated for several transient scenarios and turns out to increase correlation between measurement and simulation results significantly. By applying a fully automated simulation procedure broad operating ranges can be covered which provides a consistent insight into critical load case scenarios. This finally allows the optimization of the closing strategy and hence the overall power plant performance.

Defense AT and L. Volume 41, Number 6

DTIC Science & Technology

2012-12-01

own specialty. To paraphrase Abraham Maslow : If all you have is a hammer, everything looks like a nail. Systems engineers are supposed to take a...technology, and logistics face in the austere times we have entered. We will have to provide the ser- vices and products our warfighters need and...understanding of: (1) the constraints we must live within; (2) a willingness to prioritize our needs and accept less than we Defense AT&L: November–December

Blocking Indolamine-2,3-Dioxygenase Rebound Immune Suppression Boosts Antitumor Effects of Radio-Immunotherapy in Murine Models and Spontaneous Canine Malignancies.

PubMed

Monjazeb, Arta M; Kent, Michael S; Grossenbacher, Steven K; Mall, Christine; Zamora, Anthony E; Mirsoian, Annie; Chen, Mingyi; Kol, Amir; Shiao, Stephen L; Reddy, Abhinav; Perks, Julian R; T N Culp, William; Sparger, Ellen E; Canter, Robert J; Sckisel, Gail D; Murphy, William J

2016-09-01

Previous studies demonstrate that intratumoral CpG immunotherapy in combination with radiotherapy acts as an in-situ vaccine inducing antitumor immune responses capable of eradicating systemic disease. Unfortunately, most patients fail to respond. We hypothesized that immunotherapy can paradoxically upregulate immunosuppressive pathways, a phenomenon we term "rebound immune suppression," limiting clinical responses. We further hypothesized that the immunosuppressive enzyme indolamine-2,3-dioxygenase (IDO) is a mechanism of rebound immune suppression and that IDO blockade would improve immunotherapy efficacy. We examined the efficacy and immunologic effects of a novel triple therapy consisting of local radiotherapy, intratumoral CpG, and systemic IDO blockade in murine models and a pilot canine clinical trial. In murine models, we observed marked increase in intratumoral IDO expression after treatment with radiotherapy, CpG, or other immunotherapies. The addition of IDO blockade to radiotherapy + CpG decreased IDO activity, reduced tumor growth, and reduced immunosuppressive factors, such as regulatory T cells in the tumor microenvironment. This triple combination induced systemic antitumor effects, decreasing metastases, and improving survival in a CD8(+) T-cell-dependent manner. We evaluated this novel triple therapy in a canine clinical trial, because spontaneous canine malignancies closely reflect human cancer. Mirroring our mouse studies, the therapy was well tolerated, reduced intratumoral immunosuppression, and induced robust systemic antitumor effects. These results suggest that IDO maintains immune suppression in the tumor after therapy, and IDO blockade promotes a local antitumor immune response with systemic consequences. The efficacy and limited toxicity of this strategy are attractive for clinical translation. Clin Cancer Res; 22(17); 4328-40. ©2016 AACR. ©2016 American Association for Cancer Research.

Infrastructure and mechanical properties of a fault zone in sandstone as an outcrop analogue of a potential geothermal reservoir

NASA Astrophysics Data System (ADS)

Bauer, J. F.; Meier, S.; Philipp, S. L.

2013-12-01

Due to high drilling costs of geothermal projects, it is economically sensible to assess the potential suitability of a reservoir prior to drilling. Fault zones are of particular importance, because they may enhance fluid flow, or be flow barriers, respectively, depending on their particular infrastructure. Outcrop analogue studies are useful to analyze the fault zone infrastructure and thereby increase the predictability of fluid flow behavior across fault zones in the corresponding deep reservoir. The main aims of the present study are to 1) analyze the infrastructure and the differences of fracture system parameters in fault zones and 2) determine the mechanical properties of the faulted rocks. We measure fracture frequencies as well as orientations, lengths and apertures and take representative rock samples for each facies to obtain Young's modulus, compressive and tensile strengths in the laboratory. Since fractures reduce the stiffnesses of in situ rock masses we use an inverse correlation of the number of discontinuities to calculate effective (in situ) Young's moduli to investigate the variation of mechanical properties in fault zones. In addition we determine the rebound hardness, which correlates with the compressive strength measured in the laboratory, with a 'Schmidt-Hammer' in the field because this allows detailed maps of mechanical property variations within fault zones. Here we present the first results for a fault zone in the Triassic Lower Bunter of the Upper Rhine Graben in France. The outcrop at Cleebourg exposes the damage zone of the footwall and a clear developed fault core of a NNW-SSE-striking normal fault. The approximately 15 m wide fault core consists of fault gouge, slip zones, deformation bands and host rock lenses. Intensive deformation close to the core led to the formation of a distal fault core, a 5 m wide zone with disturbed layering and high fracture frequency. The damage zone also contains more fractures than the host rock

The Shock and Vibration Digest. Volume 15, Number 10

DTIC Science & Technology

1983-10-01

tendency to increase. The SMDE spectrum guarantees that the simply supported beam model provides a APLICATIONS OF SRS IN DESIGN conservative design for...Effects on Boron-Aluminum Composites," "The Charpy Impact Test as a Method for --- Masters Thesis (Mar 1974). Evaluating Impact Resistance of Composite...peon rings in responsq to the Impacts received Ph.D. Thesis , Georgia Inst. of Tech., 462 pp (1982) . - from the tool hammer and the workplace. A

EEG-based classification of imaginary left and right foot movements using beta rebound.

PubMed

Hashimoto, Yasunari; Ushiba, Junichi

2013-11-01

The purpose of this study was to investigate cortical lateralization of event-related (de)synchronization during left and right foot motor imagery tasks and to determine classification accuracy of the two imaginary movements in a brain-computer interface (BCI) paradigm. We recorded 31-channel scalp electroencephalograms (EEGs) from nine healthy subjects during brisk imagery tasks of left and right foot movements. EEG was analyzed with time-frequency maps and topographies, and the accuracy rate of classification between left and right foot movements was calculated. Beta rebound at the end of imagination (increase of EEG beta rhythm amplitude) was identified from the two EEGs derived from the right-shift and left-shift bipolar pairs at the vertex. This process enabled discrimination between right or left foot imagery at a high accuracy rate (maximum 81.6% in single trial analysis). These data suggest that foot motor imagery has potential to elicit left-right differences in EEG, while BCI using the unilateral foot imagery can achieve high classification accuracy, similar to ordinary BCI, based on hand motor imagery. By combining conventional discrimination techniques, the left-right discrimination of unilateral foot motor imagery provides a novel BCI system that could control a foot neuroprosthesis or a robotic foot. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Effects of a mini-trampoline rebounding exercise program on functional parameters, body composition and quality of life in overweight women.

PubMed

Cugusi, Lucia; Manca, Andrea; Serpe, Roberto; Romita, Giovanni; Bergamin, Marco; Cadeddu, Christian; Solla, Paolo; Mercuro, Giuseppe

2018-03-01

Mini-trampoline rebounding exercise (MRE) is becoming a very popular form of fitness training. Despite awareness of this activity worldwide, a limited number of studies have systematically investigated the health effects correlated with MRE training. The aim of our study was to evaluate manifold health outcomes after 12 weeks of an MRE program in a group of overweight Italian women. Eighteen overweight women (age 38.05±10.5 years, BMI: 27.6±2.1 kg/m2) were enrolled in this study. Functional profile, strength, body composition, quality of life and pain intensity were assessed at baseline and after 12 weeks of MRE. Significant improvements were observed in the measurements of anthropometric profile and body composition (circumferences, fat mass, lean and muscular mass). Both a significant decrease in systolic and diastolic blood pressure values (from 128/80.5 to 123/71 mmHg, P<0.05) and an improvement in lipid and glucose profiles were observed. At maximal exercise testing, an increase in work capacity (from 104 to 123 watts, P=0.003) and VO2max (from 15.4 to 16.9 mL/kg/min, P=0.04) was found. SF-36 showed positive changes in four of the eight items as well as in the Mental Component Summary. With regard to the Brief Pain Inventory-SF, a decrease in both pain severity and the pain interference score was detected. MRE appears feasible to ensure positive effects on overall health and can be proposed to populations that could greatly benefit from training programs, such as overweight women.

Robust Sub-harmonic Mixer at 340 GHz Using Intrinsic Resonances of Hammer-Head Filter and Improved Diode Model

NASA Astrophysics Data System (ADS)

Wang, Cheng; He, Yue; Lu, Bin; Jiang, Jun; Miao, Li; Deng, Xian-Jin; Xiong, Yong-zhong; Zhang, Jian

2017-11-01

This paper presents a sub-harmonic mixer at 340 GHz based on anti-parallel Schottky diodes (SBDs). Intrinsic resonances in low-pass hammer-head filter have been adopted to enhance the isolation for different harmonic components, while greatly minimizing the transmission loss. The application of new DC grounding structure, impedance matching structure, and suspended micro-strip mitigates the negative influences of fabrication errors from metal cavity, quartz substrate, and micro-assembly. An improved lumped element equivalent circuit model of SBDs guarantees the accuracy of simulation, which takes current-voltage (I/V) behavior, capacitance-voltage (C/V) behavior, carrier velocity saturation, DC series resistor, plasma resonance, skin effect, and four kinds of noise generation mechanisms into consideration thoroughly. The measurement indicates that with local oscillating signal of 2 mW, the lowest double sideband conversion loss is 5.5 dB at 339 GHz; the corresponding DSB noise temperature is 757 K. The 3 dB bandwidth of conversion loss is 50 GHz from 317 to 367 GHz.

Mapreduce is Good Enough? If All You Have is a Hammer, Throw Away Everything That's Not a Nail!

PubMed

Lin, Jimmy

2013-03-01

Hadoop is currently the large-scale data analysis "hammer" of choice, but there exist classes of algorithms that aren't "nails" in the sense that they are not particularly amenable to the MapReduce programming model. To address this, researchers have proposed MapReduce extensions or alternative programming models in which these algorithms can be elegantly expressed. This article espouses a very different position: that MapReduce is "good enough," and that instead of trying to invent screwdrivers, we should simply get rid of everything that's not a nail. To be more specific, much discussion in the literature surrounds the fact that iterative algorithms are a poor fit for MapReduce. The simple solution is to find alternative, noniterative algorithms that solve the same problem. This article captures my personal experiences as an academic researcher as well as a software engineer in a "real-world" production analytics environment. From this combined perspective, I reflect on the current state and future of "big data" research.

Behavior of hollow balls containing granules bouncing repeatedly off the ground

NASA Astrophysics Data System (ADS)

Hu, Min; Mu, Qing-song; Luo, Ning; Li, Gang; Peng, Ning-bo

2013-07-01

An experimental study of the behavior of hollow balls filled with some granules (mung beans or millets) bouncing repeatedly off a static flat horizontal surface is presented. We observed that the bounce number of the ball is limited and decreases regularly with an increasing number of granules. Moreover, for two balls containing a different kind of granules, their bounce numbers are basically equal when the two balls have the same mass of granules. While there is no clear relationship between the first rebound height of one ball and the number of granules, there appears an exponential decay of the second rebound height with an increase of the granule number. Furthermore, a two-dimensional numerical model has been created to find out the law of the ball's rebound height and the dissipation law of the granule nested system. A generalized prediction equation to reasonably explain the law of the bounce number has also been proposed.

Subsidence and Rebound in California's Central Valley: Effects of Pumping, Geology, and Precipitation

NASA Astrophysics Data System (ADS)

Farr, T. G.; Fairbanks, A.

2017-12-01

Recent rains in California caused a pause, and even a reversal in some areas, of the subsidence that has plagued the Central Valley for decades. The 3 main drivers of surface deformation in the Central Valley are: Subsurface hydro-geology, precipitation and surface water deliveries, and groundwater pumping. While the geology is relatively fixed in time, water inputs and outputs vary greatly both in time and space. And while subsurface geology and water inputs are reasonably well-known, information about groundwater pumping amounts and rates is virtually non-existent in California. We have derived regional maps of surface deformation in the region for the period 2006 - present which allow reconstruction of seasonal and long-term changes. In order to understand the spatial and temporal patterns of subsidence and rebound in the Central Valley, we have been compiling information on the geology and water inputs and have attempted to infer pumping rates using maps of fallowed fields and published pumping information derived from hydrological models. In addition, the spatial and temporal patterns of hydraulic head as measured in wells across the region allow us to infer the spatial and temporal patterns of groundwater pumping and recharge more directly. A better understanding of how different areas (overlying different stratigraphy) of the Central Valley respond to water inputs and outputs will allow a predictive capability, potentially defining sustainable pumping rates related to water inputs. * work performed under contract to NASA and the CA Dept. of Water Resources

Health Insurance In China: After Declining In The 1990s, Coverage Rates Rebounded To Near-Universal Levels By 2011.

PubMed

Li, Yanping; Malik, Vasanti; Hu, Frank B

2017-08-01

We analyzed trends in rates of health insurance coverage in China in the period 1991-2011 and the association of health insurance with hypertension and diabetes based on data from eight waves of the China Health and Nutrition Survey. The rate of coverage fell from 32.3 percent in 1991 to 21.9 percent in 2000, rebounding to 49.7 percent in 2006 and then rapidly climbing to 94.7 percent in 2011. Our study indicated that neither the prevalence of diabetes nor that of hypertension was significantly associated with health insurance coverage. When patients were aware of their condition or disease, those with insurance had a significantly higher likelihood of treatment for diabetes and hypertension, compared to those without insurance. We observed an association between health insurance coverage and seeking preventive care and receiving medical treatment when patients were aware of their condition or disease. Project HOPE—The People-to-People Health Foundation, Inc.

Drilling, Coring and Sampling Using Piezoelectric Actuated Mechanisms: From the USDC to a Piezo-Rotary-Hammer Drill

NASA Technical Reports Server (NTRS)

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

2012-01-01

NASA exploration missions are increasingly including sampling tasks but with the growth in engineering experience (particularly, Phoenix Scout and MSL) it is now very much recognized that planetary drilling poses many challenges. The difficulties grow significantly with the hardness of sampled material, the depth of drilling and the harshness of the environmental conditions. To address the requirements for samplers that could be operated at the conditions of the various bodies in the solar system, a number of piezoelectric actuated drills and corers were developed by the Advanced Technologies Group of JPL. The basic configuration that was conceived in 1998 is known as the Ultrasonic/Sonic Driller/Corer (USDC), and it operates as a percussive mechanism. This drill requires as low preload as 10N (important for operation at low gravity) allowing to operate with as low-mass device as 400g, use an average power as low as 2- 3W and drill rocks as hard as basalt. A key feature of this drilling mechanism is the use of a free-mass to convert the ultrasonic vibrations generated by piezoelectric stack to sonic impacts on the bit. Using the versatile capabilities f the USDC led to the development of many configurations and device sizes. Significant improvement of the penetration rate was achieved by augmenting the hammering action by rotation and use of a fluted bit to remove cuttings. To reach meters deep in ice a wireline drill was developed called the Ultrasonic/Sonic Gopher and it was demonstrated in 2005 to penetrate about 2-m deep at Antarctica. Jointly with Honeybee Robotics, this mechanism is currently being modified to incorporate rotation and inchworm operation forming Auto-Gopher to reach meters deep in rocks. To take advantage of the ability of piezoelectric actuators to operate over a wide temperatures range, piezoelectric actuated drills were developed and demonstrated to operate at as cold as -200oC and as hot as 500oC. In this paper, the developed mechanisms

Cavitation behavior observed in three monoleaflet mechanical heart valves under accelerated testing conditions.

PubMed

Lo, Chi-Wen; Liu, Jia-Shing; Li, Chi-Pei; Lu, Po-Chien; Hwang, Ned H

2008-01-01

Accelerated testing provides a substantial amount of data on mechanical heart valve durability in a short period of time, but such conditions may not accurately reflect in vivo performance. Cavitation, which occurs during mechanical heart valve closure when local flow field pressure decreases below vapor pressure, is thought to play a role in valve damage under accelerated conditions. The underlying flow dynamics and mechanisms behind cavitation bubble formation are poorly understood. Under physiologic conditions, random perivalvular cavitation is difficult to capture. We applied accelerated testing at a pulse rate of 600 bpm and transvalvular pressure of 120 mm Hg, with synchronized videographs and high-frequency pressure measurements, to study cavitation of the Medtronic Hall Standard (MHS), Medtronic Hall D-16 (MHD), and Omni Carbon (OC) valves. Results showed cavitation bubbles between 340 and 360 micros after leaflet/housing impact of the MHS, MHD, and OC valves, intensified by significant leaflet rebound. Squeeze flow, Venturi, and water hammer effects each contributed to cavitation, depending on valve design.

The Leeb Hardness Test for Rock: An Updated Methodology and UCS Correlation

NASA Astrophysics Data System (ADS)

Corkum, A. G.; Asiri, Y.; El Naggar, H.; Kinakin, D.

2018-03-01

The Leeb hardness test (LHT with test value of L D ) is a rebound hardness test, originally developed for metals, that has been correlated with the Unconfined Compressive Strength (test value of σ c ) of rock by several authors. The tests can be carried out rapidly, conveniently and nondestructively on core and block samples or on rock outcrops. This makes the relatively small LHT device convenient for field tests. The present study compiles test data from literature sources and presents new laboratory testing carried out by the authors to develop a substantially expanded database with wide-ranging rock types. In addition, the number of impacts that should be averaged to comprise a "test result" was revisited along with the issue of test specimen size. Correlation for L D and σ c for various rock types is provided along with recommended testing methodology. The accuracy of correlated σ c estimates was assessed and reasonable correlations were observed between L D and σ c . The study findings show that LHT can be useful particularly for field estimation of σ c and offers a significant improvement over the conventional field estimation methods outlined by the ISRM (e.g., hammer blows). This test is rapid and simple, with relatively low equipment costs, and provides a reasonably accurate estimate of σ c .

Experimental study of interaction between a vortex ring and a solid surface for a wide range of ring velocities

NASA Astrophysics Data System (ADS)

Nikulin, V. V.

2014-12-01

Experiments were carried out for interaction of water-travelling vortex ring with a solid surface with the normal impingement to the surface; the vortex velocity was varied by factor of 30 and the Reynolds number had 60-times span. Laminar and turbulent vortex rings have been studied. The ratio of the vortex diameter at the moment of rebound from the surface to the vortex diameter before impingement is almost independent of the vortex velocity and Reynolds number. Within the experimental accuracy, the diameter of the vortex ring after rebound equals the footprint of the vortex on the solid surface. This brings assumption that the previously observed restrictions on the trace were related to the vortex rebound from the solid surface.

Interview with Julie Viveros, RN, Director of Nursing, Charlotte Rescue Mission, Rebound men's program. Interview by Joan Kub.

PubMed

Viveros, Julie; Kub, Joan

2014-01-01

The Charlotte Rescue Mission is a 90-day residential program that serves approximately 530 men and 365 women experiencing the disease of addiction annually. It has a long rich history and has been serving the Charlotte community for over 75 years for men and almost 25 years for women. "The men's program provides a five-fold, client-centered treatment approach addressing spiritual, mental, physical, social, and vocational needs to battle addiction. The objective is to help individuals fighting addiction and homelessness to accomplish spiritual, mental, physical, social, and vocational goals and be free of addiction." "Dove's Nest, Charlotte Rescue Mission's women's recovery program, opened its doors in 1992. The program provides a structured, yet loving and stable living environment, with a dedicated staff aimed at helping women understand and deal with the core issues of addiction as a disease". (Web site: http:// charlotterescuemission.org/). I had the privilege of interviewing Julie Viveros, RN, the Director of Nursing for the Rebound men's program, about her unique role at the Rescue Mission.

Evaluation of rebound tonometry in red-eared slider turtles (Trachemys scripta elegans).

PubMed

Delgado, Cherlene; Mans, Christoph; McLellan, Gillian J; Bentley, Ellison; Sladky, Kurt K; Miller, Paul E

2014-07-01

To evaluate feasibility and accuracy of intraocular pressure (IOP) measurement by rebound tonometry in adult red-eared slider turtles and determine the effects of manual and chemical restraint on IOP. Seventeen adult red-eared slider turtles. Intraocular pressure was measured with TonoLab® and TonoVet® tonometers in conscious, unrestrained turtles. To evaluate the effects of manual restraint, turtles were restrained by digital pressure on the rostral head or proximal neck. The effect of two chemical restraint protocols (dexmedetomidine, ketamine, midazolam [DKM] and dexmedetomidine, ketamine [DK] subcutaneously) on IOP was evaluated. Triplicate TonoLab® and TonoVet® readings were compared with direct manometry in three ex vivo turtle eyes. TonoLab® correlated better with manometry at IOPs < 45 mmHg than TonoVet® (linear regression slopes of 0.89 and 0.30, respectively). Mean (±SD) IOP in unrestrained conscious turtles was significantly lower (P < 0.01) with TonoLab® (10.02 ± 0.66 mmHg) than with TonoVet® (11.32 ± 1.57 mmHg). Manual neck restraint caused a significant increase in IOP (+6.31 ± 5.59 mmHg), while manual rostral head restraint did not. Both chemical restraint protocols significantly reduced IOP (DKM: −1.0 ± 0.76 mmHg; DK: −1.79 ± 1.17) compared with measurements in conscious unrestrained turtles. Chemical and manual neck restraint affected IOP. Rostral head restraint had no significant effect on IOP and is, therefore, recommended as the appropriate restraint technique in red-eared slider turtles. TonoLab® measurements estimated actual IOP more accurately, within physiologic range, than measurements obtained using the TonoVet®. © 2013 American College of Veterinary Ophthalmologists.

EVALUATION OF REBOUND TONOMETRY IN RED-EARED SLIDER TURTLES (TRACHEMYS SCRIPTA ELEGANS)

PubMed Central

Delgado, Cherlene; Mans, Christoph; McLellan, Gillian J.; Bentley, Ellison; Sladky, Kurt K.; Miller, Paul E.

2013-01-01

Objective To evaluate feasibility and accuracy of intraocular pressure (IOP) measurement by rebound tonometry in adult red-eared slider turtles and determine the effects of manual and chemical restraint on IOP. Animal studied Seventeen adult red-eared slider turtles. Procedures IOP was measured with TonoLab® and TonoVet® tonometers in conscious, unrestrained turtles. To evaluate the effects of manual restraint, turtles were restrained by digital pressure on the rostral head or proximal neck. The effect of two chemical restraint protocols (dexmedetomidine, ketamine, midazolam [DKM] and dexmedetomidine, ketamine [DK] subcutaneously) on IOP was evaluated. Triplicate TonoLab® and TonoVet® readings were compared to direct manometry in 3 ex vivo turtle eyes. Results TonoLab® correlated better with manometry at IOPs <45 mm Hg than TonoVet® (linear regression slopes of 0.89 and 0.30 respectively). Mean (±SD) IOP in unrestrained conscious turtles was significantly lower (P<0.01) with TonoLab® (10.02 ± 0.66 mmHg) than with TonoVet® (11.32 ± 1.57 mmHg). Manual neck restraint caused a significant increase in IOP (+6.31 ± 5.59 mmHg), while manual rostral head restraint did not. Both chemical restraint protocols significantly reduced IOP (DKM: −1.0 ± 0.76 mmHg,; DK: −1.79 ± 1.17) compared to measurements in conscious unrestrained turtles. Conclusions Chemical and manual neck restraint affected IOP. Rostral head restraint had no significant effect on IOP and is, therefore, recommended as the appropriate restraint technique in red-eared-slider turtles. TonoLab® measurements estimated actual IOP more accurately, within physiologic range, than measurements obtained using the TonoVet®. PMID:25097909

A Proposed Mechanism for Development of CTE Following Concussive Events: Head Impact, Water Hammer Injury, Neurofilament Release, and Autoimmune Processes.

PubMed

Kornguth, Steven; Rutledge, Neal; Perlaza, Gabe; Bray, James; Hardin, Allen

2017-12-19

During the past decade, there has been an increasing interest in early diagnosis and treatment of traumatic brain injuries (TBI) that lead to chronic traumatic encephalopathy (CTE). The subjects involved range from soldiers exposed to concussive injuries from improvised explosive devices (IEDs) to a significant number of athletes involved in repetitive high force impacts. Although the forces from IEDs are much greater by a magnitude than those from contact sports, the higher frequency associated with contact sports allows for more controlled assessment of the mechanism of action. In our study, we report findings in university-level women soccer athletes followed over a period of four and a half years from accession to graduation. Parameters investigated included T1-, T2-, and susceptibility-weighted magnetic resonance images (SWI), IMPACT (Immediate Post-Concussion Assessment and Cognitive Testing), and C3 Logix behavioral and physiological assessment measures. The MRI Studies show several significant findings: first, a marked increase in the width of sulci in the frontal to occipital cortices; second, an appearance of subtle hemorrhagic changes at the base of the sulci; third was a sustained reduction in total brain volume in several soccer players at a developmental time when brain growth is generally seen. Although all of the athletes successfully completed their college degree and none exhibited long term clinical deficits at the time of graduation, the changes documented by MRI represent a clue to the pathological mechanism following an injury paradigm. The authors propose that our findings and those of prior publications support a mechanism of injury in CTE caused by an autoimmune process associated with the release of neural proteins from nerve cells at the base of the sulcus from a water hammer injury effect. As evidence accumulates to support this hypothesis, there are pharmacological treatment strategies that may be able to mitigate the development of

Reliability and sensitivity of the TonoLab rebound tonometer in awake Brown Norway rats.

PubMed

Morrison, John C; Jia, Lijun; Cepurna, William; Guo, Ying; Johnson, Elaine

2009-06-01

To compare the sensitivity of the TonoLab rebound tonometer with the Tono-Pen in awake Brown Norway rats and to compare their ability to predict optic nerve damage induced by experimental IOP elevation. TonoLab and Tono-Pen tonometers were calibrated in cannulated rat eyes connected to a pressure transducer. The TonoLab was used in awake animals housed in standard lighting to measure IOP during light and dark phases. Both instruments were used to monitor chronically elevated IOP produced by episcleral vein injection of hypertonic saline. Measured IOPs were correlated with quantified optic nerve damage in injected eyes. Although they were lower than transducer and Tono-Pen measurements at all levels, TonoLab readings showed an excellent linear fit with transducer readings from 20 to 80 mm Hg (R(2) = 0.99) in cannulated eyes. In awake animals housed in standard lighting, the TonoLab documented significantly higher pressures during the dark phase (27.9 +/- 1.7 mm Hg) than during the light phase (16.7 +/- 2.3 mm Hg). With elevated IOP, correlation between TonoLab and Tono-Pen readings (R(2) = 0.86, P < 0.0001) was similar to that in cannulated eyes. Although both instruments provided measurements that correlated well with optic nerve injury grade, only the Tono-Pen documented significant IOP elevation in eyes with the least amount of injury (P < 0.05). The TonoLab is sensitive enough to be used in awake Brown Norway rats, though instrument fluctuation may limit its ability to identify significant pressure elevations in eyes with minimal optic nerve damage.

There Is More than One Way to Crack an Oyster: Identifying Variation in Burmese Long-Tailed Macaque (Macaca fascicularis aurea) Stone-Tool Use

PubMed Central

Tan, Amanda; Tan, Say Hoon; Vyas, Dhaval; Malaivijitnond, Suchinda; Gumert, Michael D.

2015-01-01

We explored variation in patterns of percussive stone-tool use on coastal foods by Burmese long-tailed macaques (Macaca fascicularis aurea) from two islands in Laem Son National Park, Ranong, Thailand. We catalogued variation into three hammering classes and 17 action patterns, after examining 638 tool-use bouts across 90 individuals. Hammering class was based on the stone surface used for striking food, being face, point, and edge hammering. Action patterns were discriminated by tool material, hand use, posture, and striking motion. Hammering class was analyzed for associations with material and behavioural elements of tool use. Action patterns were not, owing to insufficient instances of most patterns. We collected 3077 scan samples from 109 macaques on Piak Nam Yai Island’s coasts, to determine the proportion of individuals using each hammering class and action pattern. Point hammering was significantly more associated with sessile foods, smaller tools, faster striking rates, smoother recoil, unimanual use, and more varied striking direction, than were face and edge hammering, while both point and edge hammering were significantly more associated with precision gripping than face hammering. Edge hammering also showed distinct differences depending on whether such hammering was applied to sessile or unattached foods, resembling point hammering for sessile foods and face hammering for unattached foods. Point hammering and sessile edge hammering compared to prior descriptions of axe hammering, while face and unattached edge hammering compared to pound hammering. Analysis of scans showed that 80% of individuals used tools, each employing one to four different action patterns. The most common patterns were unimanual point hammering (58%), symmetrical-bimanual face hammering (47%) and unimanual face hammering (37%). Unimanual edge hammering was relatively frequent (13%), compared to the other thirteen rare action patterns (<5%). We compare our study to other stone

Long-term follow-up of hypothenar hammer syndrome: a series of 47 patients.

PubMed

Marie, Isabelle; Hervé, Fabien; Primard, Etienne; Cailleux, Nicole; Levesque, Hervé

2007-11-01

Hypothenar hammer syndrome (HHS) is an uncommon form of secondary Raynaud phenomenon, occurring mainly in subjects who use the hypothenar part of the hand as a hammer; the hook of the hamate strikes the superficial palmar branch of the ulnar artery in the Guyon space, leading to occlusion and/or aneurysm of the ulnar artery. In patients with HHS, such injuries of the palmar ulnar artery may lead to severe vascular insufficiency in the hand with occlusion of digital artery. To date, only a few series have analyzed the long-term outcome of patients with HHS. This prompted us to conduct the current retrospective study to 1) evaluate the prevalence of HHS in patients with Raynaud phenomenon and 2) assess the short-term and long-term outcome in patients with HHS. From 1990 to 2006, 4148 consecutive patients were referred to the Department of Internal Medicine at the University of Rouen medical center for evaluation of Raynaud phenomenon using nailfold capillaroscopy. HHS was diagnosed in 47 of these 4148 patients (1.13% of cases).Forty-three patients (91.5%) had occupational exposure to repetitive palmar trauma. The more common occupations were factory worker (21.3%), mason (12.8%), carpenter (10.6%), and metal worker (10.6%); the mean duration of occupational exposure to repetitive palmar trauma at HHS diagnosis was 21 years. One patient (2.1%) had recreational exposure (aikido training) to repetitive trauma of the palmar ulnar artery, and 3 other patients (6.4%) developed HHS related to a single direct injury to the hypothenar area. Clinical manifestations were more often unilateral (87.2%) involving the dominant hand (93%). HHS complications included digital ischemic symptoms (ischemia: n = 21, necrosis: n = 20) and irritation of the sensory branch of the ulnar nerve (n = 11). In HHS patients, angiography demonstrated occlusion of the ulnar artery in the area of the Guyon space (59.6%), aneurysm of the ulnar artery in the area of the Guyon space (40.4%), and embolic

Seasonal subsidence and rebound in Las Vegas Valley, Nevada, observed by Synthetic Aperture Radar Interferometry

USGS Publications Warehouse

Hoffmann, Jörn; Zebker, Howard A.; Galloway, Devin L.; Amelung, Falk

2001-01-01

Analyses of areal variations in the subsidence and rebound occurring over stressed aquifer systems, in conjunction with measurements of the hydraulic head fluctuations causing these displacements, can yield valuable information about the compressibility and storage properties of the aquifer system. Historically, stress‐strain relationships have been derived from paired extensometer/piezometer installations, which provide only point source data. Because of the general unavailability of spatially detailed deformation data, areal stress‐strain relations and their variability are not commonly considered in constraining conceptual and numerical models of aquifer systems. Interferometric synthetic aperture radar (InSAR) techniques can map ground displacements at a spatial scale of tens of meters over 100 km wide swaths. InSAR has been used previously to characterize larger magnitude, generally permanent aquifer system compaction and land subsidence at yearly and longer timescales, caused by sustained drawdown of groundwater levels that produces intergranular stresses consistently greater than the maximum historical stress. We present InSAR measurements of the typically small‐magnitude, generally recoverable deformations of the Las Vegas Valley aquifer system occurring at seasonal timescales. From these we derive estimates of the elastic storage coefficient for the aquifer system at several locations in Las Vegas Valley. These high‐resolution measurements offer great potential for future investigations into the mechanics of aquifer systems and the spatial heterogeneity of aquifer system structure and material properties as well as for monitoring ongoing aquifer system compaction and land subsidence.

Early adiposity rebound is associated with metabolic risk in 7-year-old children.

PubMed

González, L; Corvalán, C; Pereira, A; Kain, J; Garmendia, M L; Uauy, R

2014-10-01

Early adiposity rebound (AR <5 years) has been consistently associated with increased obesity risk, but its relationship with metabolic markers is less clear; in addition, the biologic mechanisms involved in these associations have not been established. The objective of this study was to assess the association between timing of AR and metabolic status at age 7 years, evaluating the potential role of adiposity, adipose functionality and skeletal maturation in this association. We estimated the age of AR from the body mass index (BMI) trajectories from 0 to 7 years in 910 children from the Growth and Obesity Chilean Cohort Study (GOCS). At 7 years, we measured waist circumference (WC) and blood glucose, insulin, triglycerides and high-density lipoprotein-cholesterol levels and constructed a metabolic risk score. We also measured percent fat mass (adiposity), plasma concentrations of leptin and adiponectin (adipose functionality) and bone age using wrist ultrasound (skeletal maturation). We found that 44% of the children had an AR <5 years. Earlier AR was associated with larger WC (β: 5.10 (95% confidence interval (CI): 4.29-5.91)), higher glucose (β: 1.02 (1.00-1.03)), insulin resistance (β Homeostatic Model Assessment: 1.06 (1.03-1.09)), triglycerides (β: 10.37 (4.01-6.73)) and adverse metabolic score (β: 0.30 (0.02-0.37)). Associations decreased significantly if adiposity was added to the models (i.e. β WC: 0.85 (0.33-1.38)) and, to a lesser extent, when adipokines (i.e. β WC: 0.73 (0.14-1.32)) and skeletal maturation (i.e. β WC: 0.65 (0.10-1.20)) were added. In GOCS children, AR at a younger age predicts higher metabolic risk at 7 years; these associations are mostly explained by increased adiposity, but adipose dysfunction and accelerated skeletal maturation also have a role.

Interaction between climate, volcanism, and isostatic rebound in Southeast Alaska during the last deglaciation

USGS Publications Warehouse

Praetorius, Summer; Mix, Alan; Jensen, Britta; Froese, Duane; Milne, Glenn A.; Wolhowe, Matthew; Addison, Jason A.; Prahl, Fred

2016-01-01

Observations of enhanced volcanic frequency during the last deglaciation have led to the hypothesis that ice unloading in glaciated volcanic terrains can promote volcanism through decompression melting in the shallow mantle or a reduction in crustal magma storage time. However, a direct link between regional climate change, isostatic adjustment, and the initiation of volcanism remains to be demonstrated due to the difficulty of obtaining high-resolution well-dated records that capture short-term climate and volcanic variability traced to a particular source region. Here we present an exceptionally resolved record of 19 tephra layers paired with foraminiferal oxygen isotopes and alkenone paleotemperatures from marine sediment cores along the Southeast Alaska margin spanning the last deglacial transition. Major element compositions of the tephras indicate a predominant source from the nearby Mt. Edgecumbe Volcanic Field (MEVF). We constrain the timing of this regional eruptive sequence to 14.6–13.1 ka. The sudden increase in volcanic activity from the MEVF coincides with the onset of Bølling–Allerød interstadial warmth, the disappearance of ice-rafted detritus, and rapid vertical land motion associated with modeled regional isostatic rebound in response to glacier retreat. These data support the hypothesis that regional deglaciation can rapidly trigger volcanic activity. Rapid sea surface temperature fluctuations and an increase in local salinity (i.e., δ18Osw) variability are associated with the interval of intense volcanic activity, consistent with a two-way interaction between climate and volcanism in which rapid volcanic response to ice unloading may in turn enhance short-term melting of the glaciers, plausibly via albedo effects on glacier ablation zones.

Mycophenolate Mofetil Treatment of Systemic Sclerosis Reduces Myeloid Cell Numbers and Attenuates the Inflammatory Gene Signature in Skin.

PubMed

Hinchcliff, Monique; Toledo, Diana M; Taroni, Jaclyn N; Wood, Tammara A; Franks, Jennifer M; Ball, Michael S; Hoffmann, Aileen; Amin, Sapna M; Tan, Ainah U; Tom, Kevin; Nesbeth, Yolanda; Lee, Jungwha; Ma, Madeleine; Aren, Kathleen; Carns, Mary A; Pioli, Patricia A; Whitfield, Michael L

2018-01-31

Fewer than half of patients with systemic sclerosis demonstrate modified Rodnan skin score improvement during mycophenolate mofetil (MMF) treatment. To understand the molecular basis for this observation, we extended our prior studies and characterized molecular and cellular changes in skin biopsies from subjects with systemic sclerosis treated with MMF. Eleven subjects completed ≥24 months of MMF therapy. Two distinct skin gene expression trajectories were observed across six of these subjects. Three of the six subjects showed attenuation of the inflammatory signature by 24 months, paralleling reductions in CCL2 mRNA expression in skin and reduced numbers of macrophages and myeloid dendritic cells in skin biopsies. MMF cessation at 24 months resulted in an increased inflammatory score, increased CCL2 mRNA and protein levels, modified Rodnan skin score rebound, and increased numbers of skin myeloid cells in these subjects. In contrast, three other subjects remained on MMF >24 months and showed a persistent decrease in inflammatory score, decreasing or stable modified Rodnan skin score, CCL2 mRNA reductions, sera CCL2 protein levels trending downward, reduction in monocyte migration, and no increase in skin myeloid cell numbers. These data summarize molecular changes during MMF therapy that suggest reduction of innate immune cell numbers, possibly by attenuating expression of chemokines, including CCL2. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

The Generation of Antiphase Oscillations and Synchrony by a Rebound-Based Vertebrate Central Pattern Generator

PubMed Central

Merrison-Hort, Robert; Zhang, Hong-Yan; Borisyuk, Roman

2014-01-01

Many neural circuits are capable of generating multiple stereotyped outputs after different sensory inputs or neuromodulation. We have previously identified the central pattern generator (CPG) for Xenopus tadpole swimming that involves antiphase oscillations of activity between the left and right sides. Here we analyze the cellular basis for spontaneous left–right motor synchrony characterized by simultaneous bursting on both sides at twice the swimming frequency. Spontaneous synchrony bouts are rare in most tadpoles, and they instantly emerge from and switch back to swimming, most frequently within the first second after skin stimulation. Analyses show that only neurons that are active during swimming fire action potentials in synchrony, suggesting both output patterns derive from the same neural circuit. The firing of excitatory descending interneurons (dINs) leads that of other types of neurons in synchrony as it does in swimming. During synchrony, the time window between phasic excitation and inhibition is 7.9 ± 1 ms, shorter than that in swimming (41 ± 2.3 ms). The occasional, extra midcycle firing of dINs during swimming may initiate synchrony, and mismatches of timing in the left and right activity can switch synchrony back to swimming. Computer modeling supports these findings by showing that the same neural network, in which reciprocal inhibition mediates rebound firing, can generate both swimming and synchrony without circuit reconfiguration. Modeling also shows that lengthening the time window between phasic excitation and inhibition by increasing dIN synaptic/conduction delay can improve the stability of synchrony. PMID:24760866

Virological and immunological outcome of treatment interruption in HIV-1-infected subjects vaccinated with MVA-B

PubMed Central

Noguera-Julian, Marc; Bellido, Rocío; Puertas, Maria C.; Carrillo, Jorge; Rodriguez, C.; Perez-Alvarez, Núria; Cobarsí, Patricia; Gomez, Carmen E.; Esteban, Mariano; Jímenez, Jose Luis; García, Felipe; Blanco, Julià; Martinez-Picado, Javier; Paredes, Roger

2017-01-01

The most relevant endpoint in therapeutic HIV vaccination is the assessment of time to viral rebound or duration of sustained control of low-level viremia upon cART treatment cessation. Structured treatment interruptions (STI) are however not without risk to the patient and reliable predictors of viral rebound/control after therapeutic HIV-1 vaccination are urgently needed to ensure patient safety and guide therapeutic vaccine development. Here, we integrated immunological and virological parameters together with viral rebound dynamics after STI in a phase I therapeutic vaccine trial of a polyvalent MVA-B vaccine candidate to define predictors of viral control. Clinical parameters, proviral DNA, host HLA genetics and measures of humoral and cellular immunity were evaluated. A sieve effect analysis was conducted comparing pre-treatment viral sequences to breakthrough viruses after STI. Our results show that a reduced proviral HIV-1 DNA at study entry was independently associated with two virological parameters, delayed HIV-1 RNA rebound (p = 0.029) and lower peak viremia after treatment cessation (p = 0.019). Reduced peak viremia was also positively correlated with a decreased number of HLA class I allele associated polymorphisms in Gag sequences in the rebounding virus population (p = 0.012). Our findings suggest that proviral DNA levels and the number of HLA-associated Gag polymorphisms may have an impact on the clinical outcome of STI. Incorporation of these parameters in future therapeutic vaccine trials may guide refined immunogen design and help conduct safer STI approaches. PMID:28953921

A Proposed Mechanism for Development of CTE Following Concussive Events: Head Impact, Water Hammer Injury, Neurofilament Release, and Autoimmune Processes

PubMed Central

Kornguth, Steven; Rutledge, Neal; Perlaza, Gabe; Bray, James; Hardin, Allen

2017-01-01

During the past decade, there has been an increasing interest in early diagnosis and treatment of traumatic brain injuries (TBI) that lead to chronic traumatic encephalopathy (CTE). The subjects involved range from soldiers exposed to concussive injuries from improvised explosive devices (IEDs) to a significant number of athletes involved in repetitive high force impacts. Although the forces from IEDs are much greater by a magnitude than those from contact sports, the higher frequency associated with contact sports allows for more controlled assessment of the mechanism of action. In our study, we report findings in university-level women soccer athletes followed over a period of four and a half years from accession to graduation. Parameters investigated included T1-, T2-, and susceptibility-weighted magnetic resonance images (SWI), IMPACT (Immediate Post-Concussion Assessment and Cognitive Testing), and C3 Logix behavioral and physiological assessment measures. The MRI Studies show several significant findings: first, a marked increase in the width of sulci in the frontal to occipital cortices; second, an appearance of subtle hemorrhagic changes at the base of the sulci; third was a sustained reduction in total brain volume in several soccer players at a developmental time when brain growth is generally seen. Although all of the athletes successfully completed their college degree and none exhibited long term clinical deficits at the time of graduation, the changes documented by MRI represent a clue to the pathological mechanism following an injury paradigm. The authors propose that our findings and those of prior publications support a mechanism of injury in CTE caused by an autoimmune process associated with the release of neural proteins from nerve cells at the base of the sulcus from a water hammer injury effect. As evidence accumulates to support this hypothesis, there are pharmacological treatment strategies that may be able to mitigate the development of

The use of index tests to determine the mechanical properties of crushed aggregates from Precambrian basement complex rocks, Ado-Ekiti, SW Nigeria

NASA Astrophysics Data System (ADS)

Afolagboye, Lekan Olatayo; Talabi, Abel Ojo; Oyelami, Charles Adebayo

2017-05-01

This study assessed the possibility of using index tests to determine the mechanical properties of crushed aggregates. The aggregates used in this study were derived from major Precambrian basement rocks in Ado-Ekiti, Nigeria. Regression analyses were performed to determine the empirical relations that mechanical properties of the aggregates may have with the point load strength (IS(50)), Schmidt rebound hammer value (SHR) and unconfined compressive strength (UCS) of the rocks. For all the data, strong correlation coefficients were found between IS(50), SHR, UCS, and mechanical properties of the aggregates. The regression analysis conducted on the different rocks separately showed that correlations coefficients obtained between the IS(50), SHR, UCS and mechanical properties of the aggregates were stronger than those of the grouped rocks. The T-test and F-test showed that the derived models were valid. This study has shown that the mechanical properties of the aggregates can be estimated from IS(50), SHR and USC but the influence of rock type on the relationships should be taken into consideration.

[A comparison of rebound tonometry (ICare) with TonoPenXL and Goldmann applanation tonometry].

PubMed

Schreiber, W; Vorwerk, C K; Langenbucher, A; Behrens-Baumann, W; Viestenz, A

2007-04-01

Goldmann applanation tonometry and dynamic contour tonometry (PASCAL) are two well established slit lamp mounted tonometric methods. Intraocular pressure measurement in bedridden patients and children is often only possible using hand held tonometers (TonoPenXL, Perkins tonometer, Draeger tonometer). This study was performed to evaluate the hand held ICare tonometer, which is based on the rebound method. A total of 102 eyes were examined by two highly experienced ophthalmologists for: 1) ophthalmological status, 2) central corneal power (Zeiss IOL-Master), 3) central corneal thickness (Tomey ultrasound pachymetry, five successive measurements, SD<5%), 4) intraocular pressure (IOP) measurement with the Goldmann applantation tonometer (GAT) 1x, 5) TonoPenXL (1x), 6) ICare with three successive measurement series of 6 single measurements. The mean IOP(GAT) was 13.2+/-3.0 mmHg compared with the mean IOP(TonoPenXL) (13.4+/-3.1 mmHg) and with the IOP(ICare) (mean value of first measurement series: 13.4+/-3.1 mmHg). The series of measurements with the ICare showed a tonography effect (decrease of IOP from 14.6 mmHg at the first measurement and 14.2 mmHg at the second to 14.0 at the third measurement). The ICare-measurements were highly reliable (Cronbach's alpha=0.974) and showed a good correlation between the measurement series (r=0.592-0.642; p<0.001). There was a great intra-individual variability of up to 17 mmHg between the GAT, TonoPenXL and ICare methods. The ICare tonometer is easy to handle and high reliability. The data are comparable with those from the Goldmann tonometer. A tonography effect of 0.6 mmHg in the successive measurement series was found.

Post-Inhibitory Rebound Spikes in Rat Medial Entorhinal Layer II/III Principal Cells: In Vivo, In Vitro, and Computational Modeling Characterization

PubMed Central

Ferrante, Michele; Shay, Christopher F.; Tsuno, Yusuke; William Chapman, G.; Hasselmo, Michael E.

2017-01-01

Abstract Medial entorhinal cortex Layer-II stellate cells (mEC-LII-SCs) primarily interact via inhibitory interneurons. This suggests the presence of alternative mechanisms other than excitatory synaptic inputs for triggering action potentials (APs) in stellate cells during spatial navigation. Our intracellular recordings show that the hyperpolarization-activated cation current (Ih) allows post-inhibitory-rebound spikes (PIRS) in mEC-LII-SCs. In vivo, strong inhibitory-post-synaptic potentials immediately preceded most APs shortening their delay and enhancing excitability. In vitro experiments showed that inhibition initiated spikes more effectively than excitation and that more dorsal mEC-LII-SCs produced faster and more synchronous spikes. In contrast, PIRS in Layer-II/III pyramidal cells were harder to evoke, voltage-independent, and slower in dorsal mEC. In computational simulations, mEC-LII-SCs morphology and Ih homeostatically regulated the dorso-ventral differences in PIRS timing and most dendrites generated PIRS with a narrow range of stimulus amplitudes. These results suggest inhibitory inputs could mediate the emergence of grid cell firing in a neuronal network. PMID:26965902

Water-hammer pressure waves interaction at cross-section changes in series in viscoelastic pipes

NASA Astrophysics Data System (ADS)

Meniconi, S.; Brunone, B.; Ferrante, M.

2012-08-01

In view of scarcity of both experimental data and numerical models concerning transient behavior of cross-section area changes in pressurized liquid flow, the paper presents laboratory data and numerical simulation of the interaction of a surge wave with a partial blockage by a valve, a single pipe contraction or expansion and a series of pipe contraction/expansion in close proximity.With regard to a single change of cross-section area, laboratory data point out the completely different behavior with respect to one of the partially closed in-line valves with the same area ratio. In fact, for the former the pressure wave interaction is not regulated by the steady-state local head loss. With regard to partial blockages, transient tests have shown that the smaller the length, the more intense the overlapping of pressure waves due to the expansion and contraction in series.Numerically, the need for taking into account both the viscoelasticity and unsteady friction is demonstrated, since the classical water-hammer theory does not simulate the relevant damping of pressure peaks and gives rise to a time shifting between numerical and laboratory data. The transient behavior of a single local head loss has been checked by considering tests carried out in a system with a partially closed in-line valve. As a result, the reliability of the quasi steady-state approach for local head loss simulation has been demonstrated in viscoelastic pipes. The model parameters obtained on the basis of transients carried out in single pipe systems have then been used to simulate transients in the more complex pipe systems. These numerical experiments show the great importance of the length of the small-bore pipe with respect to one of the large-bore pipes. Precisely, until a gradually flow establishes in the small-bore pipe, the smaller such a length, the better the quality of the numerical simulation.

Controllable seismic source

DOEpatents

Gomez, Antonio; DeRego, Paul Jeffrey; Ferrell, Patrick Andrew; Thom, Robert Anthony; Trujillo, Joshua J.; Herridge, Brian

2015-09-29

An apparatus for generating seismic waves includes a housing, a strike surface within the housing, and a hammer movably disposed within the housing. An actuator induces a striking motion in the hammer such that the hammer impacts the strike surface as part of the striking motion. The actuator is selectively adjustable to change characteristics of the striking motion and characteristics of seismic waves generated by the impact. The hammer may be modified to change the physical characteristics of the hammer, thereby changing characteristics of seismic waves generated by the hammer. The hammer may be disposed within a removable shock cavity, and the apparatus may include two hammers and two shock cavities positioned symmetrically about a center of the apparatus.

Controllable seismic source

DOEpatents

Gomez, Antonio; DeRego, Paul Jeffrey; Ferrel, Patrick Andrew; Thom, Robert Anthony; Trujillo, Joshua J.; Herridge, Brian

2014-08-19

An apparatus for generating seismic waves includes a housing, a strike surface within the housing, and a hammer movably disposed within the housing. An actuator induces a striking motion in the hammer such that the hammer impacts the strike surface as part of the striking motion. The actuator is selectively adjustable to change characteristics of the striking motion and characteristics of seismic waves generated by the impact. The hammer may be modified to change the physical characteristics of the hammer, thereby changing characteristics of seismic waves generated by the hammer. The hammer may be disposed within a removable shock cavity, and the apparatus may include two hammers and two shock cavities positioned symmetrically about a center of the apparatus.

Translations on Near East and North Africa, Number 1635, Background to May 1977 Israeli Geneal Electrions

DTIC Science & Technology

1977-04-04

the spirit of the social humanism of the 20th Century. The liberalism of the Democratic Movement for Change is according to the clas- sic model of...prime minister to have superior power, like a ministering angel, in any case, to be without any human weakness. Among other things, these general...them from a precious human reservoir, had afforded them a space in which to function, had provided them with an anvil for their hammer--now

Use of an Ultrasonic/Sonic Driller/Corer to Obtain Sample Powder for CHEMIN, a Combined XRD/XRF Instrument

NASA Technical Reports Server (NTRS)

Chipera, S. J.; Bish, D. L.; Vaniman, D. T.; Sherrit, S.; Bar-Cohen, Y.; Sarrazin, P.; Blake, D. F.

2003-01-01

A miniature CHEMIN XRD/XRF (X-Ray Diffraction/X-Ray Fluourescence) instrument is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed in order to enable XRD analysis on an extraterrestrial body is how best to obtain a representative sample powder for analysis. For XRD powder diffraction analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a 2-dimensional detector as used in the CHEMIN instrument will produce good results with poorly prepared powders, the quality of the data will improve if the sample is fine-grained and randomly oriented. An Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL is an effective mechanism of sampling rock to produce cores and powdered cuttings. It requires low axial load (< 5N) and thus offers significant advantages for operation from lightweight platforms and in low gravity environments. The USDC is lightweight (<0.5kg), and can be driven at low power (<5W) using duty cycling. It consists of an actuator with a piezoelectric stack, ultrasonic horn, free-mass, and drill bit. The stack is driven with a 20 kHz AC voltage at resonance. The strain generated by the piezoelectric is amplified by the horn by a factor of up to 10 times the displacement amplitude. The tip impacts the free-mass and drives it into the drill bit in a hammering action. The free-mass rebounds to interact with the horn tip leading to a cyclic rebound at frequencies in the range of 60-1000 Hz. It does not require lubricants, drilling fluid or bit sharpening and it has the potential to operate at high and low temperatures using a suitable choice of piezoelectric material. To assess whether the powder from an ultrasonic drill would be adequate for analyses by an XRD/XRF spectrometer such as CHEMIN, powders obtained from the JPL

Single-particle Analyses of Compositions, Morphology, and Viscosity of Aerosol Particles Collected During GoAmazon2014

NASA Astrophysics Data System (ADS)

Adachi, K.; Gong, Z.; Bateman, A. P.; Martin, S. T.; Cirino, G. G.; Artaxo, P.; Sedlacek, A. J., III; Buseck, P. R.

2014-12-01

Single-particle analysis using transmission electron microscopy (TEM) shows composition and morphology of individual aerosol particles collected during the GoAmazon2014 campaign. These TEM results indicate aerosol types and mixing states, both of which are important for evaluating particle optical properties and cloud condensation nuclei activity. The samples were collected at the T3 site, which is located in the Amazon forest with influences from the urban pollution plume from Manaus. Samples were also collected from the T0 site, which is in the middle of the jungle with minimal to no influences of anthropogenic sources. The aerosol particles mainly originated from 1) anthropogenic pollution (e.g., nanosphere soot, sulfate), 2) biogenic emissions (e.g., primary biogenic particles, organic aerosols), and 3) long-range transport (e.g., sea salts). We found that the biogenic organic aerosol particles contain homogeneously distributed potassium. Particle viscosity is important for evaluating gas-particle interactions and atmospheric chemistry for the particles. Viscosity can be estimated from the rebounding behavior at controlled relative humidities, i.e., highly viscous particles display less rebound on a plate than low-viscosity particles. We collected 1) aerosol particles from a plate (non-rebounded), 2) those that had rebounded from the plate and were then captured onto an adjacent sampling plate, and 3) particles from ambient air using a separate impactor sampler. Preliminary results show that more than 90% of non-rebounded particles consisted of nanosphere soot with or without coatings. The coatings mostly consisted of organic matter. Although rebounded particles also contain nanosphere soot (number fraction 64-69%), they were mostly internally mixed with sulfate, organic matter, or their mixtures. TEM tilted images suggested that the rebounded particles were less deformed on the substrate, whereas the non-rebounded particles were more deformed, which could

Reclaimed mineland curve number response to temporal distribution of rainfall

USGS Publications Warehouse

Warner, R.C.; Agouridis, C.T.; Vingralek, P.T.; Fogle, A.W.

2010-01-01

The curve number (CN) method is a common technique to estimate runoff volume, and it is widely used in coal mining operations such as those in the Appalachian region of Kentucky. However, very little CN data are available for watersheds disturbed by surface mining and then reclaimed using traditional techniques. Furthermore, as the CN method does not readily account for variations in infiltration rates due to varying rainfall distributions, the selection of a single CN value to encompass all temporal rainfall distributions could lead engineers to substantially under- or over-size water detention structures used in mining operations or other land uses such as development. Using rainfall and runoff data from a surface coal mine located in the Cumberland Plateau of eastern Kentucky, CNs were computed for conventionally reclaimed lands. The effects of temporal rainfall distributions on CNs was also examined by classifying storms as intense, steady, multi-interval intense, or multi-interval steady. Results indicate that CNs for such reclaimed lands ranged from 62 to 94 with a mean value of 85. Temporal rainfall distributions were also shown to significantly affect CN values with intense storms having significantly higher CNs than multi-interval storms. These results indicate that a period of recovery is present between rainfall bursts of a multi-interval storm that allows depressional storage and infiltration rates to rebound. ?? 2010 American Water Resources Association.

Interparticle collision of natural sediment grains in water

USGS Publications Warehouse

Schmeeckle, Mark W.; Nelson, Jonathan M.; Pitlick, John; Bennett, James P.

2001-01-01

Elastohydrodynamic theory and measurements of particle impacts on an inclined glass plane in water are used to investigate the mechanics of interparticle collisions in sediment‐transporting flows. A collision Stokes number is proposed as a measure of the momentum of an interparticle collision versus the viscous pressure force in the interstitial gap between colliding particles. The viscous pressure force opposes motion of the particles on approach and rebound. A Stokes number of between 39 and 105 is estimated as the critical range below which particle impacts are completely viscously damped and above which impacts are partially elastic. The critical Stokes number is shown to roughly coincide with the Bagnold number transition between macroviscous and grain inertial debris flows and the transition between damped and partially elastic bed load transport saltation impacts. The nonspherical nature of natural particles significantly alters the motion of the center of mass after a partially elastic collision. The normal to the point of contact between the particles does not necessarily go through the center of mass. Thus normal rebound of the center of mass may not occur. A model of particle motion after rebound for particles of arbitrary shape, conserving both linear and angular momentum, is proposed.

Declining and rebounding unhealthy alcohol consumption during the first year of HIV care in rural Uganda, using phosphatidylethanol to augment self-report.

PubMed

Hahn, Judith A; Emenyonu, Nneka I; Fatch, Robin; Muyindike, Winnie R; Kekiibina, Allen; Carrico, Adam W; Woolf-King, Sarah; Shiboski, Stephen

2016-02-01

We examined whether unhealthy alcohol consumption, which negatively impacts HIV outcomes, changes after HIV care entry overall and by several factors. We also compared using phosphatidylethanol (PEth, an alcohol biomarker) to augment self-report to using self-report alone. A prospective 1-year observational cohort study with quarterly visits. Large rural HIV clinic in Mbarara, Uganda. A total of 208 adults (89 women and 119 men) entering HIV care, reporting any prior year alcohol consumption. Unhealthy drinking was PEth+ (≥ 50 ng/ml) or Alcohol Use Disorders Identification Test-Consumption+ (AUDIT-C+, over 3 months, women ≥ 3; men ≥ 4). We calculated adjusted odds ratios (AOR) for unhealthy drinking per month since baseline, and interactions of month since baseline with perceived health, number of HIV symptoms, antiretroviral therapy (ART), gender and self-reported prior unhealthy alcohol use. The majority of participants (64%) were unhealthy drinkers (PEth+ or AUDIT-C+) at baseline. There was no significant trend in unhealthy drinking overall [per-month AOR: 1.01; 95% confidence interval (CI) = 0.94-1.07], while the per-month AORs were 0.91 (95% CI = 0.83-1.00) and 1.11 (95% CI = 1.01-1.22) when participants were not yet on ART and on ART, respectively (interaction P-value < 0.01). In contrast, 44% were AUDIT-C+; the per-month AORs for being AUDIT-C+ were 0.89 (95% CI = 0.85-0.95) overall, and 0.84 (95% CI = 0.78-0.91) and 0.97 (95% CI = 0.89-1.05) when participants were not on and were on ART, respectively. Unhealthy alcohol use among Ugandan adults entering HIV care declines prior to the start of anti-retroviral therapy but rebounds with time. Augmenting self-reported alcohol use with biomarkers increases the ability of current alcohol use measurements to detect unhealthy alcohol use. © 2015 Society for the Study of Addiction.

Erosion of metals by multiple impacts with water

NASA Technical Reports Server (NTRS)

Rudy, S. L.; Thiruvengadam, A.

1971-01-01

Investigation determines - relation between impact velocity and minimum number of impacts producing visible erosion, relation between high frequency fatigue stresses and number of cycles to failure, water-hammer stresses relation to high frequency endurance limit, erosion rate as exposure time function, and correlates experimental data with recent theory.

Age at adiposity rebound: determinants and association with nutritional status and the metabolic syndrome at adulthood.

PubMed

Péneau, S; González-Carrascosa, R; Gusto, G; Goxe, D; Lantieri, O; Fezeu, L; Hercberg, S; Rolland-Cachera, M F

2016-07-01

Early-life growth characteristics and in particular age at adiposity rebound (AR), have been shown to impact nutritional status later in life but studies investigating the association with long-term health remain scarce. Our aims were to identify determinants of age at AR and its relationship with nutritional status and cardiometabolic risk factors at adulthood. A total of 1465 subjects aged 20-60 years participated in this retrospective cohort study. Height, weight, waist circumference, blood glucose, lipids and blood pressure were measured at adulthood. Childhood weight, height, gestational age, birth weight and early nutrition were collected retrospectively from health booklets and age at AR was assessed. Participants self-reported parental silhouettes. Associations were assessed using multiple linear and logistic regression. An earlier AR was associated with higher body mass index and waist circumference at adulthood in both men and women (P<0.0001). In addition, women with an earlier occurrence of AR had higher triglyceride (P=0.001), low-density lipoprotein-cholesterol (P=0.001), systolic (P=0.02) and diastolic blood pressure (P=0.04) at adulthood. Both men (odds ratio (OR) (95% confidence interval (CI)): 0.82 (0.70-0.95)) and women (OR (95% CI): 0.84 (0.73-0.96) with an AR occurring earlier were more likely to develop a metabolic syndrome. Larger parental silhouette was associated with an earlier AR. This long-term study showed that age at AR was associated with nutritional status and metabolic syndrome at adulthood. These results highlight the importance of monitoring childhood growth so as to help identify children at risk of developing an adverse cardiometabolic profile in adulthood. AR determinants for use in overweight surveillance were identified.

Visual persuasion and politics: ideology and symbols of the totalitarian regimes'--case study: hammer and sickle.

PubMed

Svilicić, Niksa; Maldini, Pero

2013-06-01

Unlike all other autocracies, authoritarian regimes are, as the ultimate form of authoritarianism, a distinct phenomenon of the modern era. Caused by the crisis of liberal democracy and industrial capitalism of the early twentieth century, and led by radical populist political movements/parties and their leaders, they established themselves as the regimes which marked one of the greatest degrees of unfreedom. The article analyzes the specific sociostructural, sociocultural and sociopsychological aspects of the formation of totalitarian regimes (particularly communism), as well as their political system, ideological foundations and modus operandi. In doing so, it particularly emphasizes the dissolution of civil society and its substitution by a political society as a key structural determinant, authoritarianism and fear as a sociopsychological basis, and repression as the functional basis of operation for totalitarian regimes. In that context, it analyzes the political, anthropological and visual aspects of the symbols of totalitarian regimes, their archetypal (mythological, religious, ethnic, cultural, historical) meaning, and explains their function (political, anthropological, sociocultural, and sociopsychological) in the development and preservation of totalitarian regimes. Using the example of the hammer and sickle, a typical symbol of communism, it shows a substantial and communicational (particularly visual) dimension of symbol, by breakdown by the elements of semiotics (signum, designatum, interpretant) and its sub-disciplines (semantics, pragmatics, sintactics). On this basis, it tries to show the decisive power of political symbols over the political perceptions and political behavior of individuals and entire social groups, i.e. their manipulative power by meanings assigned to them by totalitarian authorities and forms of their communication, with the goal of preserving the totalitarian regime.

Analytical solution and numerical study on water hammer in a pipeline closed with an elastically attached valve

NASA Astrophysics Data System (ADS)

Henclik, Sławomir

2018-03-01

The influence of dynamic fluid-structure interaction (FSI) onto the course of water hammer (WH) can be significant in non-rigid pipeline systems. The essence of this effect is the dynamic transfer of liquid energy to the pipeline structure and back, which is important for elastic structures and can be negligible for rigid ones. In the paper a special model of such behavior is analyzed. A straight pipeline with a steady flow, fixed to the floor with several rigid supports is assumed. The transient is generated by a quickly closed valve installed at the end of the pipeline. FSI effects are assumed to be present mainly at the valve which is fixed with a spring dash-pot attachment. Analysis of WH runs, especially transient pressure changes, for various stiffness and damping parameters of the spring dash-pot valve attachment is presented in the paper. The solutions are found analytically and numerically. Numerical results have been computed with the use of an own computer program developed on the basis of the four equation model of WH-FSI and the specific boundary conditions formulated at the valve. Analytical solutions have been found with the separation of variables method for slightly simplified assumptions. Damping at the dash-pot is taken into account within the numerical study. The influence of valve attachment parameters onto the WH courses was discovered and it was found the transient amplitudes can be reduced. Such a system, elastically attached shut-off valve in a pipeline or other, equivalent design can be a real solution applicable in practice.

Test to Extract Soil Properties Using the Seismic HammerTM Active Seismic Source

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

Lee, Rebekah F.; Abbott, Robert E.

Geologic material properties are necessary parameters for ground motion modeling and are difficult and expensive to obtain via traditional methods. Alternative methods to estimate soil properties require a measurement of the ground's response to a force. A possible method of obtaining these measurements is active-source seismic surveys, but measurements of the ground response at the source must also be available. The potential of seismic sources to obtain soil properties is limited, however, by the repeatability of the source. Explosives, and hammer surveys are not repeatable because of variable ground coupling or swing strength. On the other hand, the Seismic Hammermore » TM (SH) is consistent in the amount of energy it inputs into the ground. In addition, it leaves large physical depressions as a result of ground compaction. The volume of ground compaction varies by location. Here, we hypothesize that physical depressions left in the earth by the SH correlate to energy recorded by nearby geophones, and therefore are a measurement of soil physical properties. Using measurements of the volume of shot holes, we compare the spatial distribution of the volume of ground compacted between the different shot locations. We then examine energy recorded by the nearest 50 geophones and compare the change in amplitude across hits at the same location. Finally, we use the percent difference between the energy recorded by the first and later hits at a location to test for a correlation to the volume of the shot depressions. We find that: * Ground compaction at the shot-depression does cluster geographically, but does not correlate to known surface features. * Energy recorded by nearby geophones reflects ground refusal after several hits. * There is no correlation to shot volume and changes in energy at particular shot locations. Deeper material properties (i.e. below the depth of surface compaction) may be contributing to the changes in energy propagation. * Without further

Solid-on-solid contact in a sphere-wall collision in a viscous fluid

NASA Astrophysics Data System (ADS)

Birwa, Sumit Kumar; Rajalakshmi, G.; Govindarajan, Rama; Menon, Narayanan

2018-04-01

We study experimentally the collision between a sphere falling through a viscous fluid and a solid plate below. It is known that there is a well-defined threshold Stokes number above which the sphere rebounds from such a collision. Our experiment tests for direct contact between the colliding bodies and, contrary to prior theoretical predictions, shows that solid-on-solid contact occurs even for Stokes numbers just above the threshold for rebounding. The dissipation is fluid dominated, though details of the contact mechanics depend on the surface and bulk properties of the solids. Our experiments and a model calculation indicate that mechanical contact between the two colliding objects is generic and will occur for any realistic surface roughness.

Inversion Analysis of Postseismic Deformation in Poroelastic Material Using Finite Element Method

NASA Astrophysics Data System (ADS)

Kawamoto, S.; Ito, T.; Hirahara, K.

2005-12-01

Following a large earthquake, postseismic deformations in the focal source region have been observed by several geodetic measurements. To explain the postseismic deformations, researchers have proposed some physical mechanisms known as afterslip, viscoelastic relaxation and poroelastic rebound. There are a number of studies about postseismic deformations but for poroelastic rebound. So, we calculated the postseismic deformations caused by afterslip and poroelastic rebound using modified FEM code _eCAMBIOT3D_f originally developed by Geotech. Lab. Gunma University, Japan (2003). The postseismic deformations caused by both afterslip and poroelastic rebound are characteristically different from those caused only by afterslip. This suggests that the slip distributions on the fault estimated from geodetic measurements also change. Because of this, we developed the inversion method that accounts for both afterslip and poroelastic rebound using FEM to estimate the difference of slip distributions on the fault quantitatively. The inversion analysis takes following steps. First, we calculate the coseismic and postseismic response functions on each fault segment induced by the unit slip. Where postseismic response function indicate the poroelastic rebound. Next, we make the observation equations at each time step using the response functions and estimate the spatiotemporal distribution of slip on the fault. In solving this inverse problem, we assume the slip distributions on the fault are smooth in space and time except for rapid change (coseismic change). Because the hyperparameters that control the smoothness of spatial and temporal distributions of slip are needed, we determine the best hyperparameters using ABIC. In this presentation, we introduce the example of analysis results using this method.

Nebivolol withdrawal results in blood pressure returning toward pretreatment levels, but without rebound symptoms: phase IV randomized trial.

PubMed

Lewin, Andrew; Lasseter, Kenneth C; Dong, Fang; Whalen, John C

2012-01-01

Rapid withdrawal of antihypertensive drugs may lead to blood pressure (BP) increase above pretreatment values or symptoms such as palpitations, chest pain, and tremor. This phase IV trial assessed the consequences of abrupt and stepwise withdrawal of nebivolol, a β(1)-selective blocker, in individuals with stage I-II hypertension. After a 4- to 5-week placebo washout phase and 12-week single-blind nebivolol treatment (10-40 mg/day, titrated based on BP response), participants achieving BP control (systolic BP [SBP]/diastolic BP [DBP] <140/90 mm Hg) or response (SBP decrease ≥10 mm Hg or DBP decrease ≥5 mm Hg) entered a 4-week, randomized, double-blind phase of continued nebivolol treatment (n = 102) or withdrawal to placebo (n = 105). Primary and secondary efficacy measures were changes in mean sitting DBP and SBP, respectively, analyzed using an analysis of covariance model. Safety and tolerability were also assessed. In the withdrawal phase, nebivolol and placebo groups demonstrated mean DBP increases of 1.8 and 7.7 mm Hg, respectively (P < .001), and SBP increases of 3.5 and 7.6 mm Hg (P = .011). Twenty-three (22.5%) nebivolol-treated and 18 (17.1%) placebo-treated participants experienced a treatment-emergent adverse event. No adverse events associated with β-blocker withdrawal and considered causally related to nebivolol were reported. Nebivolol withdrawal resulted in a mean BP increase near pretreatment levels and was not associated with rebound hypertension. Copyright © 2012 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Computational compliance criteria in water hammer modelling

NASA Astrophysics Data System (ADS)

Urbanowicz, Kamil

2017-10-01

Among many numerical methods (finite: difference, element, volume etc.) used to solve the system of partial differential equations describing unsteady pipe flow, the method of characteristics (MOC) is most appreciated. With its help, it is possible to examine the effect of numerical discretisation carried over the pipe length. It was noticed, based on the tests performed in this study, that convergence of the calculation results occurred on a rectangular grid with the division of each pipe of the analysed system into at least 10 elements. Therefore, it is advisable to introduce computational compliance criteria (CCC), which will be responsible for optimal discretisation of the examined system. The results of this study, based on the assumption of various values of the Courant-Friedrichs-Levy (CFL) number, indicate also that the CFL number should be equal to one for optimum computational results. Application of the CCC criterion to own written and commercial computer programmes based on the method of characteristics will guarantee fast simulations and the necessary computational coherence.

Grain-scale modeling and splash parametrization for aeolian sand transport.

PubMed

Lämmel, Marc; Dzikowski, Kamil; Kroy, Klaus; Oger, Luc; Valance, Alexandre

2017-02-01

The collision of a spherical grain with a granular bed is commonly parametrized by the splash function, which provides the velocity of the rebounding grain and the velocity distribution and number of ejected grains. Starting from elementary geometric considerations and physical principles, like momentum conservation and energy dissipation in inelastic pair collisions, we derive a rebound parametrization for the collision of a spherical grain with a granular bed. Combined with a recently proposed energy-splitting model [Ho et al., Phys. Rev. E 85, 052301 (2012)PLEEE81539-375510.1103/PhysRevE.85.052301] that predicts how the impact energy is distributed among the bed grains, this yields a coarse-grained but complete characterization of the splash as a function of the impact velocity and the impactor-bed grain-size ratio. The predicted mean values of the rebound angle, total and vertical restitution, ejection speed, and number of ejected grains are in excellent agreement with experimental literature data and with our own discrete-element computer simulations. We extract a set of analytical asymptotic relations for shallow impact geometries, which can readily be used in coarse-grained analytical modeling or computer simulations of geophysical particle-laden flows.

The Auto-Gopher Deep Drill

NASA Technical Reports Server (NTRS)

Badescu, Mircea

2014-01-01

Subsurface penetration by coring, drilling or abrading is of great importance for a large number of space and earth applications. An Ultrasonic/Sonic Drill/Corer (USDC) has been in development at JPL's Nondestructive Evaluation and Advanced Actuators (NDEAA) lab as an adaptable tool for many of these applications. The USDC uses a novel drive mechanism to transform the high frequency ultrasonic or sonic vibrations of the tip of a horn into a lower frequency sonic hammering of a drill bit through an intermediate free-flying mass. The USDC device idea has been implemented at various scales from handheld drills to large diameter coring devices. A series of computer programs that model the function and performance of the USDC device were developed and were later integrated into an automated modeling package. The USDC has also evolved from a purely hammering drill to a rotary hammer drill as the design requirements increased form small diameter shallow drilling to large diameter deep coring. A synthesis of the Auto-Gopher development is presented in this paper.

Rapid rebound of soil respiration following partial stand disturbance by tree girdling in a temperate deciduous forest.

PubMed

Levy-Varon, Jennifer H; Schuster, William S F; Griffin, Kevin L

2014-04-01

Forests serve an essential role in climate change mitigation by removing CO2 from the atmosphere. Within a forest, disturbance events can greatly impact C cycling and subsequently influence the exchange of CO2 between forests and the atmosphere. This connection makes understanding the forest C cycle response to disturbance imperative for climate change research. The goal of this study was to examine the temporal response of soil respiration after differing levels of stand disturbance for 3 years at the Black Rock Forest (southeastern NY, USA; oaks comprise 67% of the stand). Tree girdling was used to mimic pathogen attack and create the following treatments: control, girdling all non-oaks (NOG), girdling half of the oak trees (O50), and girdling all the oaks (OG). Soil respiratory rates on OG plots declined for 2 years following girdling before attaining a full rebound of belowground activity in the third year. Soil respiration on NOG and O50 were statistically similar to the control for the duration of the study although a trend for a stronger decline in respiration on O50 relative to NOG occurred in the first 2 years. Respiratory responses among the various treatments were not proportional to the degree of disturbance and varied over time. The short-lived respiratory response on O50 and OG suggests that belowground activity is resilient to disturbance; however, sources of the recovered respiratory flux on these plots are likely different than they were pre-treatment. The differential taxon response between oaks and non-oaks suggests that after a defoliation or girdling event, the temporal response of the soil respiratory flux may be related to the C allocation pattern of the affected plant group.

Neuromagnetic imaging of movement-related cortical oscillations in children and adults: age predicts post-movement beta rebound.

PubMed

Gaetz, W; Macdonald, M; Cheyne, D; Snead, O C

2010-06-01

We measured visually-cued motor responses in two developmentally separate groups of children and compared these responses to a group of adults. We hypothesized that if post-movement beta rebound (PMBR) depends on developmentally sensitive processes, PMBR will be greatest in adults and progressively decrease in children performing a basic motor task as a function of age. Twenty children (10 young children 4-6 years; 10 adolescent children 11-13 years) and 10 adults all had MEG recorded during separate recordings of right and left index finger movements. Beta band (15-30 Hz) event-related desynchronization (ERD) of bi-lateral sensorimotor areas was observed to increase significantly from both contralateral and ipsilateral MI with age. Movement-related gamma synchrony (60-90 Hz) was also observed from contralateral MI for each age group. However, PMBR was significantly reduced in the 4-6 year group and, while more prominent, remained significantly diminished in the adolescent (11-13 year) age group as compared to adults. PMBR measures were weak or absent in the youngest children tested and appear maximally from bilateral MI in adults. Thus PMBR may reflect an age-dependent inhibitory process of the primary motor cortex which comes on-line with normal development. Previous studies have shown PMBR may be observed from MI following a variety of movement-related tasks in adult participants - however, the origin and purpose of the PMBR is unclear. The current study shows that the expected PMBR from MI observed from adults is increasingly diminished in adolescent and young children respectively. A reduction in PMBR from children may reflect reduced motor cortical inhibition. Relatively less motor inhibition may facilitate neuronal plasticity and promote motor learning in children. Copyright 2010 Elsevier Inc. All rights reserved.

Enhancing Immune Checkpoint Inhibitor Therapy In Kidney Cancer

DTIC Science & Technology

2016-10-01

AWARD NUMBER: W81XWH-15-1-0141 TITLE: Enhancing Immune Checkpoint Inhibitor therapy in Kidney Cancer PRINCIPAL INVESTIGATOR: Hans-Joerg Hammers...Immune Checkpoint Inhibitor therapy in Kidney Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH- 15-1-0141 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...to develop strategies to enhance immune checkpoint inhibition in kidney cancer. The work is designed to test different strategies to induce or

Enhancing Immune Checkpoint Inhibitor Therapy in Kidney Cancer

DTIC Science & Technology

2017-10-01

AWARD NUMBER: W81XWH-15-1-0141 TITLE: Enhancing Immune Checkpoint Inhibitor therapy in Kidney Cancer PRINCIPAL INVESTIGATOR: Hans-Joerg Hammers...SUBTITLE Enhancing Immune Checkpoint Inhibitor therapy in Kidney Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH- 15-1-0141 5c. PROGRAM ELEMENT NUMBER...immune checkpoint inhibition in kidney cancer . The work is designed to test different strategies to induce or enhance the abscopal in a kidney cancer

Post-movement beta rebound abnormality as indicator of mirror neuron system dysfunction in autistic spectrum disorder: an MEG study.

PubMed

Honaga, Eiko; Ishii, Ryouhei; Kurimoto, Ryu; Canuet, Leonides; Ikezawa, Koji; Takahashi, Hidetoshi; Nakahachi, Takayuki; Iwase, Masao; Mizuta, Ichiro; Yoshimine, Toshiki; Takeda, Masatoshi

2010-07-12

The mu rhythm is regarded as a physiological indicator of the human mirror neuron system (MNS). The dysfunctional MNS hypothesis in patients with autistic spectrum disorder (ASD) has often been tested using EEG and MEG, targeting mu rhythm suppression during action observation/execution, although with controversial results. We explored neural activity related to the MNS in patients with ASD, focusing on power increase in the beta frequency band after observation and execution of movements, known as post-movement beta rebound (PMBR). Multiple source beamformer (MSBF) and BrainVoyager QX were used for MEG source imaging and statistical group analysis, respectively. Seven patients with ASD and ten normal subjects participated in this study. During the MEG recordings, the subjects were asked to observe and later execute object-related hand actions performed by an experimenter. We found that both groups exhibited pronounced PMBR exceeding 20% when observing and executing actions with a similar topographic distribution of maximal activity. However, significantly reduced PMBR was found only during the observation condition in the patients relative to controls in cortical regions within the MNS, namely the sensorimotor area, premotor cortex and superior temporal gyrus. Reduced PMBR during the observation condition was also found in the medial prefrontal cortex. These results support the notion of a dysfunctional execution/observation matching system related to MNS impairment in patients with ASD, and the feasibility of using MEG to detect neural activity, in particular PMBR abnormalities, as an index of MNS dysfunction during performance of motor or cognitive tasks. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Gradual cessation of proton pump inhibitor (PPI) treatment may prevent rebound acid secretion, measured by the alkaline tide method, in dyspepsia and reflux patients.

PubMed

Niv, Yaron

2011-09-01

Gastro esophageal reflux disease and ulcer related or non-ulcer dyspepsia, attacks 20% of the Western population. These millions of patients are treated continuously with PPI for different periods, many for many years. Recently, rebound acid hypersecretion was recognized as a major clinical event after cessation of PPI therapy. Sustained hypergastrinemia due to daily PPI therapy causes increased acid-secretory capacity that appears when the drug is stopped. The transient increase in blood and urinary pH following gastric secretion has been termed the alkaline tide phenomenon. Carbonic acid, formed in the presence of the enzyme carbonic anhydrase, neutralizes intracellular hydroxyl ions produced as a result of luminal acid secretion. The bicarbonate generated is removed from the cell via the baso-lateral chloride bicarbonate exchanger. We have shown in several studies that this phenomenon parallels acid secretion. Thus, stimulation of acid secretion with test meal increased base excess maximally after 45 min and these changes parallel peak acid output measured in gastric aspirate. We hypothesize that gradual step down cessation of PPI will prevent this clinical relevant event. By measuring alkaline tide after PPI cessation we may prove this hypothesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dexamethasone as Adjuvant to Bupivacaine Prolongs the Duration of Thermal Antinociception and Prevents Bupivacaine-Induced Rebound Hyperalgesia via Regional Mechanism in a Mouse Sciatic Nerve Block Model

PubMed Central

An, Ke; Elkassabany, Nabil M.; Liu, Jiabin

2015-01-01

Background Dexamethasone has been studied as an effective adjuvant to prolong the analgesia duration of local anesthetics in peripheral nerve block. However, the route of action for dexamethasone and its potential neurotoxicity are still unclear. Methods A mouse sciatic nerve block model was used. The sciatic nerve was injected with 60ul of combinations of various medications, including dexamethasone and/or bupivacaine. Neurobehavioral changes were observed for 2 days prior to injection, and then continuously for up to 7 days after injection. In addition, the sciatic nerves were harvested at either 2 days or 7 days after injection. Toluidine blue dyeing and immunohistochemistry test were performed to study the short-term and long-term histopathological changes of the sciatic nerves. There were six study groups: normal saline control, bupivacaine (10mg/kg) only, dexamethasone (0.5mg/kg) only, bupivacaine (10mg/kg) combined with low-dose (0.14mg/kg) dexamethasone, bupivacaine (10mg/kg) combined with high-dose (0.5mg/kg) dexamethasone, and bupivacaine (10mg/kg) combined with intramuscular dexamethasone (0.5mg/kg). Results High-dose perineural dexamethasone, but not systemic dexamethasone, combined with bupivacaine prolonged the duration of both sensory and motor block of mouse sciatic nerve. There was no significant difference on the onset time of the sciatic nerve block. There was “rebound hyperalgesia” to thermal stimulus after the resolution of plain bupivacaine sciatic nerve block. Interestingly, both low and high dose perineural dexamethasone prevented bupivacaine-induced hyperalgesia. There was an early phase of axon degeneration and Schwann cell response as represented by S-100 expression as well as the percentage of demyelinated axon and nucleus in the plain bupivacaine group compared with the bupivacaine plus dexamethasone groups on post-injection day 2, which resolved on post-injection day 7. Furthermore, we demonstrated that perineural dexamethasone

Recession Rebound

ERIC Educational Resources Information Center

Weinstein, Margery

2011-01-01

A return to normal after a crisis is a good thing. Who doesn't want back what once seemed lost? The problem is it usually isn't a simple task figuring out how to patch together a scaled-back training program. When the recession hit in fall 2008, trainers were asked to scale down programming and make do with fewer resources. With a recovery in full…

75 FR 48941 - Takes of Marine Mammals Incidental to Specified Activities; Piling and Structure Removal in...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-12

... subsistence uses (where relevant), and if the permissible methods of taking and requirements pertaining to the... mouth of Chapman Bay. Pilings would be removed by vibratory hammer extraction methods and structures... day would be removed via vibratory hammer extraction methods. Typically the hammer vibrates for less...

Rebound of residual plasma viremia after initial decrease following addition of intravenous immunoglobulin to effective antiretroviral treatment of HIV.

PubMed

Mellberg, Tomas; Gonzalez, Veronica D; Lindkvist, Annica; Edén, Arvid; Sönnerborg, Anders; Sandberg, Johan K; Svennerholm, Bo; Gisslén, Magnus

2011-06-28

High dosage of intravenous immunoglobulin (IVIG) has been observed as a possible activator of HIV gene expression in latently infected resting CD4+ T-cells, leading to a substantial decrease in both the reservoir and the residual plasma viremia when added to effective ART. IVIG treatment has also been reported to expand T regulatory cells (Tregs). The aim of this study was to evaluate possible long-term effect of IVIG treatment on residual viremia and T-lymphocyte activation. Nine HIV-infected subjects on effective ART included in a previously reported study on IVIG treatment were evaluated 48-104 weeks after therapy. In addition, 14 HIV-infected controls on suppressive ART were included. HIV-1 RNA was analyzed in cell-free plasma by using an ultrasensitive PCR-method with a detection limit of 2 copies/mL. T-lymphocyte activation markers and serum interleukins were measured. Plasma residual viremia rebounded to pre-treatment levels, 48-104 weeks after the initial decrease that was observed following treatment with high-dosage IVIG. No long-term effect was observed regarding T-lymphocyte activation markers, T-regulatory cells or serum interleukins. In a post-hoc analysis, a correlation between plasma HIV-1-RNA and CD4+ T-cell count was found in both IVIG-treated patients and controls. These results indicate that the decrease in the latent HIV-1 pool observed during IVIG treatment is transient. Although not our primary objective, we found a correlation between HIV-1 RNA and CD4+ T-cell count suggesting the possibility that patients with a higher CD4+ T-cell count might harbor a larger residual pool of latently infected CD4+ T-cells.

Time trends in BMI, body fatness, and adiposity rebound among boys from Kraków (Poland) from 1983 to 2010.

PubMed

Kowal, Małgorzata; Kryst, Łukasz; Woronkowicz, Agnieszka; Brudecki, Janusz; Sobiecki, Jan

2015-01-01

The prevalence of childhood obesity has been increasing during the last decades in many countries, but less is known about secular trends in growth curves covering the whole childhood span. The main purpose of this study was to explore changes in body weight, height, BMI, percent body fat (%BF), adiposity rebound (AR), and pubertal timing in boys from Kraków between 1983 and 2010. Totally, 4,986 boys (3-18 years) were measured during cross-sectional studies. Using the results of height, weight, and skinfold measurements, BMI and %BF were calculated. The LMS method was used to construct BMI and %BF percentiles. Three cut-off points were distinguished in individual age groups of the subjects-below the 15th percentile, 50th percentile, and above the 85th percentile. The mean age at pubarche was calculated by the probit method. The boys from 2010 were taller and heavier than the boys from 1983. Before the time of AR, boys from 2010 had lower BMI, but after AR had higher BMI than boys from 1983. An earlier AR appeared in all BMI 2010 percentile curves as compared to 1983. The boys from 2010 also showed an acceleration of sexual maturation and earlier Tanner Stage II, equaling 11.80 years. In boys from 2010, AR occurs earlier than in boys from 1983. Changes in timing of AR cannot be explained only by changes in degree of body adiposity. Early AR could be a marker of the acceleration of development. © 2015 Wiley Periodicals, Inc.

Natalizumab Discontinuation and Treatment Strategies in Patients with Multiple Sclerosis (MS): A Retrospective Study from Two Italian MS Centers.

PubMed

Lo Re, Marianna; Capobianco, Marco; Ragonese, Paolo; Realmuto, Sabrina; Malucchi, Simona; Berchialla, Paola; Salemi, Giuseppe; Bertolotto, Antonio

2015-12-01

Natalizumab (NTZ) discontinuation can be followed by multiple sclerosis (MS) disease reactivation. Currently no disease-modifying drug (DMD) has been shown to be able to abolish disease reactivation. The aims of the current study were: (1) to determine the frequency of MS reactivation after NTZ discontinuation; (2) to evaluate predictors of reactivation risk, and (3) to compare the effect of different treatments in reducing this risk. Data from 132 patients with MS followed-up for 2 years before NTZ treatment and 1 year after interruption were collected from two Italian MS centers and retrospectively evaluated. Overall, 72 of 132 patients (54.5%) had relapses after NTZ discontinuation and 60 of 125 patients (48%), who had magnetic resonance imaging, had radiological reactivation. Rebound was observed in 28 of 132 patients (21.2%). A higher number of relapses in the 2 years before NTZ treatment, a longer washout period, and a lower number NTZ infusions correlated with reactivation and rebound. Untreated patients (n = 37) had higher clinical and radiological activity and rebound in comparison to patients receiving DMDs. Moreover, a lower risk of relapses was found in patients treated with second-line therapies (NTZ and fingolimod) than in those treated with first-line therapies (interferon beta, glatiramer acetate, teriflunomide, azathioprine). Interestingly, no disease reactivation in off-label treatment (rituximab, autologous hematopoietic stem cell transplantation) was observed. NTZ discontinuation is a risk for MS reactivation and rebound. An alternative treatment should be promptly resumed mainly in patients with a previous very active disease course and with a shorter NTZ therapy. Second-line therapies demonstrate superiority in preventing relapses after NTZ discontinuation.

Percussion tool

DOEpatents

Reed, Teddy R.

2006-11-28

A percussion tool is described and which includes a housing mounting a tool bit; a reciprocally moveable hammer borne by the housing and which is operable to repeatedly strike the tool bit; and a reciprocally moveable piston enclosed within the hammer and which imparts reciprocal movement to the reciprocally moveable hammer.

The Rural Rebound of the 1990s and Beyond

Treesearch

Kenneth M. Johnson

2002-01-01

During most of the twentieth century, rural America experienced widespread and protracted outmigration. The magnitude of this loss varied from decade to decade, but the pattern was quite consistent: rural areas grew only when an excess of births over deaths offset the number of people who moved away from these communities. Many rural communities suffered population...

29 CFR 1926.603 - Pile driving equipment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... strength. (4) Stop blocks shall be provided for the leads to prevent the hammer from being raised against the head block. (5) A blocking device, capable of safely supporting the weight of the hammer, shall be... hammer. (6) Guards shall be provided across the top of the head block to prevent the cable from jumping...

29 CFR 1926.603 - Pile driving equipment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... strength. (4) Stop blocks shall be provided for the leads to prevent the hammer from being raised against the head block. (5) A blocking device, capable of safely supporting the weight of the hammer, shall be... hammer. (6) Guards shall be provided across the top of the head block to prevent the cable from jumping...

29 CFR 1926.603 - Pile driving equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... strength. (4) Stop blocks shall be provided for the leads to prevent the hammer from being raised against the head block. (5) A blocking device, capable of safely supporting the weight of the hammer, shall be... hammer. (6) Guards shall be provided across the top of the head block to prevent the cable from jumping...

29 CFR 1926.603 - Pile driving equipment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... strength. (4) Stop blocks shall be provided for the leads to prevent the hammer from being raised against the head block. (5) A blocking device, capable of safely supporting the weight of the hammer, shall be... hammer. (6) Guards shall be provided across the top of the head block to prevent the cable from jumping...

29 CFR 1926.603 - Pile driving equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... strength. (4) Stop blocks shall be provided for the leads to prevent the hammer from being raised against the head block. (5) A blocking device, capable of safely supporting the weight of the hammer, shall be... hammer. (6) Guards shall be provided across the top of the head block to prevent the cable from jumping...

Dermal safety assessment of Arm & Hammer laundry products formulated for sensitive skin.

PubMed

Frederick, Douglas M; Vorwerk, Linda; Gupta, Archana; Ghassemi, Annahita

2017-09-01

product (Arm & Hammer Free & Clear) and other nonirritant controls. In the Wrist Band Wear test, exposure to laundered fabrics under exaggerated conditions gave similar results for the test and control products, with no objective signs of skin irritation, and no self-reported persistent adverse sensory effects. Very mild, transient and isolated sensory effects were noted in daily diaries by a small proportion of subjects, and were similar for the test and control products. The Safety In-Use tests evaluated 4-week exposure to product and laundered fabrics under realistic use conditions. There were no clinically objective signs of skin irritation, and reports of transitory, mild sensory effects were minimal and similar for the test and controls. A comprehensive skin safety program on a lightly scented sensitive skin laundry formulation (i.e. Arm & Hammer™ Sensitive Skin plus Skin-Friendly Fresh Scent) conducted among panels of self-assessed sensitive skin subjects demonstrated that the presence of a light fragrance did not adversely impact skin compatibility in any of the testing protocols when the product was compared to a similar product with no fragrance. The lightly fragranced product demonstrated overall skin compatibility and mildness when tested in a self-assessed sensitive skin population, and compared favorably to currently marketed sensitive skin products.

Use of Artificial Burrows by Burrowing Owls (Athene cunicularia) at the HAMMER Facility on the U.S. Department of Energy Hanford Site

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

Alexander, Amanda K.; Sackschewsky, Michael R.; Duberstein, Corey A.

In 2003 the U.S. Department of Energy (DOE) constructed an Emergency Vehicle Operations Course (EVOC) at the Hazardous Material Management and Emergency Response Training and Education Center (HAMMER) in the southern portion of the Hanford Site. Preliminary surveys during 2001 identified an active burrowing owl (Athene cunicularia) burrow and three burrowing owls within the proposed development area. Burrowing owls were classified as a federal species of concern, a Washington State ?candidate? species, a Washington Department of Fish and Wildlife priority species, and a Hanford Site Biological Resources Management Plan Level III resource. Therefore, the mitigation action plan for the projectmore » included the installation of twenty artificial burrows around EVOC in the spring of 2003. The mitigation plan established a success criterion of five percent annual use of the burrows by owls. In July 2005, a field survey of the EVOC burrow complex was conducted to determine use and demography at each site. Burrow locations were mapped and signs of activity (feces, owl tracks, castings, feathers) were recorded. Out of the twenty burrows, twelve were found to be active. Of the eight inactive burrows three appeared to have been active earlier in the 2005 breeding season. A total of nineteen owls were counted but demography could not be determined. It appears that the EVOC mitigation exceeded burrow use goals during 2005. Continued site monitoring and maintenance, according to mitigation plan guidelines should be conducted as prescribed.« less

The Particle Distribution in Liquid Metal with Ceramic Particles Mould Filling Process

NASA Astrophysics Data System (ADS)

Dong, Qi; Xing, Shu-ming

2017-09-01

Adding ceramic particles in the plate hammer is an effective method to increase the wear resistance of the hammer. The liquid phase method is based on the “with the flow of mixed liquid forging composite preparation of ZTA ceramic particle reinforced high chromium cast iron hammer. Preparation method for this system is using CFD simulation analysis the particles distribution of flow mixing and filling process. Taking the 30% volume fraction of ZTA ceramic composite of high chromium cast iron hammer as example, by changing the speed of liquid metal viscosity to control and make reasonable predictions of particles distribution before solidification.

Wild capuchin monkeys spontaneously adjust actions when using hammer stones of different mass to crack nuts of different resistance.

PubMed

Liu, Qing; Fragaszy, Dorothy M; Visalberghi, Elisabetta

2016-09-01

Expert tool users are known to adjust their actions skillfully depending on aspects of tool type and task. We examined if bearded capuchin monkeys cracking nuts with stones of different mass adjusted the downward velocity and the height of the stone when striking palm nuts. During a field experiment carried out in FBV (Piauí, Brazil), eight adult wild capuchin monkeys (five males) cracked Orbygnia nuts of varied resistance with hammer stones differing in mass. From recorded videos, we identified the highest strike per nut-cracking episode, and for this strike, we calculated the height to which the monkey lifted the stone, the maximum velocity of the stone during the downward phase, the work done on the stone, and the kinetic energy of the strike. We found that individual capuchins achieved average maximum kinetic energy of 8.7-16.1 J when using stones between 0.9 and 1.9 kg, and maximum kinetic energy correlated positively with mass of the stone. Monkeys lifted all the stones to an individually consistent maximum height but added more work to the stone when using lighter stones. One male and one female monkey lifted stones higher when they cracked more resistant nuts. The high resistance of the Orbygnia nut elicits production of maximum kinetic energy, which the monkeys modulate to some degree by adding work to lighter stones. Capuchin monkeys, like chimpanzees, modulate their actions in nut-cracking, indicating skilled action, although neither species regulates kinetic energy as precisely as skilled human stone knappers. Kinematic analyses promise to yield new insights into the ways and extent to which nonhuman tool users develop expertise. Am J Phys Anthropol 161:53-61, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

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

Huang, Xiongyi; Groves, John T.

Since our initial report in 1976, the oxygen rebound mechanism has become the consensus mechanistic feature for an expanding variety of enzymatic C–H functionalization reactions and small molecule biomimetic catalysts. For both the biotransformations and models, an initial hydrogen atom abstraction from the substrate (R–H) by high-valent iron-oxo species (Fe n=O) generates a substrate radical and a reduced iron hydroxide, [Fe n-1–OH ·R]. This caged radical pair then evolves on a complicated energy landscape through a number of reaction pathways, such as oxygen rebound to form R–OH, rebound to a non-oxygen atom affording R–X, electron transfer of the incipient radicalmore » to yield a carbocation, R +, desaturation to form olefins, and radical cage escape. These various flavors of the rebound process, often in competition with each other, give rise to the wide range of C–H functionalization reactions performed by iron-containing oxygenases. In this review, we first recount the history of radical rebound mechanisms, their general features, and key intermediates involved. We will discuss in detail the factors that affect the behavior of the initial caged radical pair and the lifetimes of the incipient substrate radicals. Several representative examples of enzymatic C–H transformations are selected to illustrate how the behaviors of the radical pair [Fe n-1–OH ·R] determine the eventual reaction outcome. Finally, we discuss the powerful potential of “radical rebound” processes as a general paradigm for developing novel C–H functionalization reactions with synthetic, biomimetic catalysts. We envision that new chemistry will continue to arise by bridging enzymatic “radical rebound” with synthetic organic chemistry.« less

Anthropogenic influences on the physical state of submicron particulate matter over a tropical forest

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

Bateman, Adam P.; Gong, Zhaoheng; Harder, Tristan H.

The occurrence of nonliquid and liquid physical states of submicron atmospheric particulate matter (PM) downwind of an urban region in central Amazonia was investigated. Measurements were conducted during two intensive operating periods (IOP1 and IOP2) that took place during the wet and dry seasons of the GoAmazon2014/5 campaign. Air masses representing variable influences of background conditions, urban pollution, and regional- and continental-scale biomass burning passed over the research site. As the air masses varied, particle rebound fraction, an indicator of physical state, was measured in real time at ground level using an impactor apparatus. Micrographs collected by transmission electron microscopymore » confirmed that liquid particles adhered, while nonliquid particles rebounded. Relative humidity (RH) was scanned to collect rebound curves. When the apparatus RH matched ambient RH, 95 % of the particles adhered as a campaign average. Secondary organic material, produced for the most part by the oxidation of volatile organic compounds emitted from the forest, produces liquid PM over this tropical forest. During periods of anthropogenic influence, by comparison, the rebound fraction dropped to as low as 60 % at 95 % RH. Analyses of the mass spectra of the atmospheric PM by positive-matrix factorization (PMF) and of concentrations of carbon monoxide, total particle number, and oxides of nitrogen were used to identify time periods affected by anthropogenic influences, including both urban pollution and biomass burning. The occurrence of nonliquid PM at high RH correlated with these indicators of anthropogenic influence. A linear model having as output the rebound fraction and as input the PMF factor loadings explained up to 70 % of the variance in the observed rebound fractions. Anthropogenic influences can contribute to the presence of nonliquid PM in the atmospheric particle population through the combined effects of molecular species that increase

Anthropogenic influences on the physical state of submicron particulate matter over a tropical forest

DOE PAGES

Bateman, Adam P.; Gong, Zhaoheng; Harder, Tristan H.; ...

2017-02-06

The occurrence of nonliquid and liquid physical states of submicron atmospheric particulate matter (PM) downwind of an urban region in central Amazonia was investigated. Measurements were conducted during two intensive operating periods (IOP1 and IOP2) that took place during the wet and dry seasons of the GoAmazon2014/5 campaign. Air masses representing variable influences of background conditions, urban pollution, and regional- and continental-scale biomass burning passed over the research site. As the air masses varied, particle rebound fraction, an indicator of physical state, was measured in real time at ground level using an impactor apparatus. Micrographs collected by transmission electron microscopymore » confirmed that liquid particles adhered, while nonliquid particles rebounded. Relative humidity (RH) was scanned to collect rebound curves. When the apparatus RH matched ambient RH, 95 % of the particles adhered as a campaign average. Secondary organic material, produced for the most part by the oxidation of volatile organic compounds emitted from the forest, produces liquid PM over this tropical forest. During periods of anthropogenic influence, by comparison, the rebound fraction dropped to as low as 60 % at 95 % RH. Analyses of the mass spectra of the atmospheric PM by positive-matrix factorization (PMF) and of concentrations of carbon monoxide, total particle number, and oxides of nitrogen were used to identify time periods affected by anthropogenic influences, including both urban pollution and biomass burning. The occurrence of nonliquid PM at high RH correlated with these indicators of anthropogenic influence. A linear model having as output the rebound fraction and as input the PMF factor loadings explained up to 70 % of the variance in the observed rebound fractions. Anthropogenic influences can contribute to the presence of nonliquid PM in the atmospheric particle population through the combined effects of molecular species that increase

Interventions to Reduce Myopia Progression in Children.

PubMed

Tay, Su Ann; Farzavandi, Sonal; Tan, Donald

2017-03-01

Efforts to reduce the progression of myopia in childhood are on the rise, due to an increasing incidence of myopia worldwide and its associated sight-threatening complications. Interventions are aimed at reducing myopia in childhood and include environmental considerations, spectacles, contact lenses, and pharmacological agents. We reviewed recent literature with interventions aimed at reducing myopia progression in children and found that a number of interventions were significant in reducing the progression of myopia. Of these interventions, atropine showed the largest dose-related effect on myopia progression control. Although higher doses are associated with side effects of pupil dilatation, loss of accommodation, near vision blur, and rebound phenomenon, low-dose atropine has also been shown to provide effective myopia control with minimal side effects and rebound. To a lesser degree, bifocal soft contact lenses have also been shown to be effective in reducing the progression of myopia, though compliance is an issue. Similarly, orthokeratology lenses have also been shown to be effective in reducing axial length elongation and myopia progression, though long-term data on its rebound effects are unavailable.

Impact of Viscous Droplets on Superamphiphobic Surfaces

NASA Astrophysics Data System (ADS)

Zhao, Binyu; Chen, Longquan; Deng, Xu

2016-11-01

Superamphiphobic coating is promising for various applications in industry, e.g. self-cleaning windows, where the impingement of droplets on surfaces is commonly encountered. In this work, we experimentally investigated the impact of droplets with similar surface tension (63-72 mN/m) but much different viscosity (1-150 mPa s) on superamphiphobic surfaces. We found that droplets can rebound from the superamphiphobic surfaces when the impact velocity is larger than a critical value, which linearly increases with the liquid viscosity. Droplet with higher viscosity spreads, retracts slower, and eventually rebounds lower and fewer times than that of low viscous droplet. These findings have important implications for surface engineers to use superamphiphobic coatings. Furthermore, we measured the maximum spreading factors for droplet impact on superamphiphobic surfaces and proposed a simple model based on energy conversation to describe its relationship to the Weber number and Reynolds number.

Development of the Elastic Rebound Strike-slip (ERS) Fault Model for Teaching Earthquake Science to Non-science Students

NASA Astrophysics Data System (ADS)

Glesener, G. B.; Peltzer, G.; Stubailo, I.; Cochran, E. S.; Lawrence, J. F.

2009-12-01

The Modeling and Educational Demonstrations Laboratory (MEDL) at the University of California, Los Angeles has developed a fourth version of the Elastic Rebound Strike-slip (ERS) Fault Model to be used to educate students and the general public about the process and mechanics of earthquakes from strike-slip faults. The ERS Fault Model is an interactive hands-on teaching tool which produces failure on a predefined fault embedded in an elastic medium, with adjustable normal stress. With the addition of an accelerometer sensor, called the Joy Warrior, the user can experience what it is like for a field geophysicist to collect and observe ground shaking data from an earthquake without having to experience a real earthquake. Two knobs on the ERS Fault Model control the normal and shear stress on the fault. Adjusting the normal stress knob will increase or decrease the friction on the fault. The shear stress knob displaces one side of the elastic medium parallel to the strike of the fault, resulting in changing shear stress on the fault surface. When the shear stress exceeds the threshold defined by the static friction of the fault, an earthquake on the model occurs. The accelerometer sensor then sends the data to a computer where the shaking of the model due to the sudden slip on the fault can be displayed and analyzed by the student. The experiment clearly illustrates the relationship between earthquakes and seismic waves. One of the major benefits to using the ERS Fault Model in undergraduate courses is that it helps to connect non-science students with the work of scientists. When students that are not accustomed to scientific thought are able to experience the scientific process first hand, a connection is made between the scientists and students. Connections like this might inspire a student to become a scientist, or promote the advancement of scientific research through public policy.

Distinct Phenotype, Longitudinal Changes of Numbers and Cell-Associated Virus in Blood Dendritic Cells in SIV-Infected CD8-Lymphocyte Depleted Macaques

PubMed Central

Soulas, Caroline; Autissier, Patrick J.; Burdo, Tricia H.; Lifson, Jeffrey D.; Williams, Kenneth C.

2015-01-01

Loss of circulating CD123+ plasmacytoid dendritic cells (pDCs) during HIV infection is well established. However, changes of myeloid DCs (mDCs) are ambiguous since they are studied as a homogeneous CD11c+ population despite phenotypic and functional heterogeneity. Heterogeneity of CD11c+ mDCs in primates is poorly described in HIV and SIV infection. Using multiparametric flow cytometry, we monitored longitudinally cell number and cell-associated virus of CD123+ pDCs and non-overlapping subsets of CD1c+ and CD16+ mDCs in SIV-infected CD8-depleted rhesus macaques. The numbers of all three DC subsets were significantly decreased by 8 days post-infection. Whereas CD123+ pDCs were persistently depleted, numbers of CD1c+ and CD16+ mDCs rebounded. Numbers of CD1c+ mDCs significantly increased by 3 weeks post-infection while numbers of CD16+ mDCs remained closer to pre-infection levels. We found similar changes in the numbers of all three DC subsets in CD8 depleted animals as we found in animals that were SIV infected animals that were not CD8 lymphocyte depleted. CD16+ mDCs and CD123+ pDCs but not CD1c+ mDCs were significantly decreased terminally with AIDS. All DC subsets harbored SIV RNA as early as 8 days and then throughout infection. However, SIV DNA was only detected in CD123+ pDCs and only at 40 days post-infection consistent with SIV RNA, at least in mDCs, being surface-bound. Altogether our data demonstrate that SIV infection differently affects CD1c+ and CD16+ mDCs where CD16+ but not CD1c+ mDCs are depleted and might be differentially regulated in terminal AIDS. Finally, our data underline the importance of studying CD1c+ and CD16+ mDCs as discrete populations, and not as total CD11c+ mDCs. PMID:25915601

Ground hardness and injury in community level Australian football.

PubMed

Twomey, Dara M; Finch, Caroline F; Lloyd, David G; Elliott, Bruce C; Doyle, Tim L A

2012-07-01

To describe the risk and details of injuries associated with ground hardness in community level Australian football (AF). Prospective injury surveillance with periodic objective ground hardness measurement. 112 ground hardness assessments were undertaken using a Clegg hammer at nine locations across 20 grounds, over the 2007 and 2008 AF seasons. Details of 352 injuries sustained by community level players on those grounds were prospectively collected as part of a large randomised controlled trial. The ground location of the injury was matched to the nearest corresponding ground hardness Clegg hammer readings, in gravities (g), which were classified from unacceptably low (<30 g) to unacceptably high hardness (>120 g). Clegg hammer readings ranged from 25 to 301 g. Clegg hammer hardness categories from low/normal to high/normal were associated with the majority of injuries, with only 3.7% (13 injuries) on unacceptably high hardness and 0.3% (1 injury) on the unacceptably low hardness locations. Relative to the preferred range of hardness, the risk of sustaining an injury on low/normal hardness locations was 1.31 (95%CI: 1.06-1.62) times higher and 1.82 (95%CI: 1.17-2.85) times higher on locations with unacceptably high hardness. The more severe injuries occurred with low/normal ground hardness. Despite the low number of injuries, the risk of sustaining an injury on low/normal and unacceptably hard grounds was significantly greater than on the preferred range of hardness. Notably, the severity of the injuries sustained on unacceptably hard grounds was lower than for other categories of hardness. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Aberrant development of post-movement beta rebound in adolescents and young adults with fetal alcohol spectrum disorders

PubMed Central

Vakhtin, Andrei A.; Kodituwakku, Piyadasa W.; Garcia, Christopher M.; Tesche, Claudia D.

2015-01-01

Dependent on maternal (e.g. genetic, age) and exposure (frequency, quantity, and timing) variables, the effects of prenatal alcohol exposure on the developing fetus are known to vary widely, producing a broad range of morphological anomalies and neurocognitive deficits in offspring, referred to as fetal alcohol spectrum disorders (FASD). Maternal drinking during pregnancy remains a leading risk factor for the development of intellectual disabilities in the US. While few functional findings exist today that shed light on the mechanisms responsible for the observed impairments in individuals with FASD, animal models consistently report deleterious effects of early alcohol exposure on GABA-ergic inhibitory pathways. The post-motor beta rebound (PMBR), a transient increase of 15–30 Hz beta power in the motor cortex that follows the termination of movement, has been implicated as a neural signature of GABA-ergic inhibitory activity. Further, PMBR has been shown to be a reliable predictor of age in adolescents. The present study sought to investigate any differences in the development of PMBR between FASD and control groups. Beta event-related de-synchronization (ERD) and movement-related gamma synchronization (MRGS), although not clearly linked to brain maturation, were also examined. Twenty-two participants with FASD and 22 age and sex-matched controls (12–22 years old) underwent magnetoencephalography scans while performing an auditory oddball task, which required a button press in response to select target stimuli. The data surrounding the button presses were localized to the participants' motor cortices, and the time courses from the locations of the maximally evoked PMBR were subjected to wavelet analyses. The subsequent analysis of PMBR, ERD, and MRGS revealed a significant interaction between group and age in their effects on PMBR. While age had a significant effect on PMBR in the controls, no simple effects of age were detected in the FASD group. The FASD

Characteristics of phase 3-like activity and rebound excitation triggered by hexamethonium and atropine administration in the ovine small bowel.

PubMed

Romański, K W

2010-02-01

Administration of hexamethonium (Hx) and atropine inhibits myoelectric and motor activity and then evokes a stimulatory effect called rebound excitation (RE) in the ovine small bowel. RE has not been precisely characterized so far and it is possible that it is composed of different types of motility. This study was thus devoted to characterizing these excitatory changes in the myoelectric and motor activity of the small bowel, particularly in the duodenum in conscious sheep. These alterations occurred in response to different intravenous doses of Hx and atropine administered alone or in combinations during various phases of the migrating myoelectric or motor complex (MMC) in the fasted and non-fasted sheep. Initially two basic types of excitatory response to the cholinergic blockade were found. In the course of chronic experiments different doses of Hx and atropine evoked phase 3-like activity (unorganized phase 3 of the MMC or its fragments) alternating with the less regular RE and the duration of these changes was related to the drug dose. In the nonfasted sheep these changes were less pronounced than in the fasted animals. When the drug was given during phase 1 of the MMC, RE did not occur or was greatly reduced. Administration of Hx and atropine in the course of phase 2a and phase 2b of the MMC produced roughly similar effects. Hx triggered stronger phase 3-like activity and RE than atropine. Combinations of Hx and atropine induced an additive effect, more evident in the fasted animals. These actions of Hx and atropine, thus, appear to involve at least partly the same intramural pathways. It is concluded that Hx and atropine evoke phase 3-like activity alternating with RE as the secondary stimulatory response in conscious sheep and both these types of the intestinal motility represent two distinct motility patterns.

Ciliary neurotrophic factor activates leptin-like pathways and reduces body fat, without cachexia or rebound weight gain, even in leptin-resistant obesity.

PubMed

Lambert, P D; Anderson, K D; Sleeman, M W; Wong, V; Tan, J; Hijarunguru, A; Corcoran, T L; Murray, J D; Thabet, K E; Yancopoulos, G D; Wiegand, S J

2001-04-10

Ciliary Neurotrophic Factor (CNTF) was first characterized as a trophic factor for motor neurons in the ciliary ganglion and spinal cord, leading to its evaluation in humans suffering from motor neuron disease. In these trials, CNTF caused unexpected and substantial weight loss, raising concerns that it might produce cachectic-like effects. Countering this possibility was the suggestion that CNTF was working via a leptin-like mechanism to cause weight loss, based on the findings that CNTF acts via receptors that are not only related to leptin receptors, but also similarly distributed within hypothalamic nuclei involved in feeding. However, although CNTF mimics the ability of leptin to cause fat loss in mice that are obese because of genetic deficiency of leptin (ob/ob mice), CNTF is also effective in diet-induced obesity models that are more representative of human obesity, and which are resistant to leptin. This discordance again raised the possibility that CNTF might be acting via nonleptin pathways, perhaps more analogous to those activated by cachectic cytokines. Arguing strongly against this possibility, we now show that CNTF can activate hypothalamic leptin-like pathways in diet-induced obesity models unresponsive to leptin, that CNTF improves prediabetic parameters in these models, and that CNTF acts very differently than the prototypical cachectic cytokine, IL-1. Further analyses of hypothalamic signaling reveals that CNTF can suppress food intake without triggering hunger signals or associated stress responses that are otherwise associated with food deprivation; thus, unlike forced dieting, cessation of CNTF treatment does not result in binge overeating and immediate rebound weight gain.

On the rebound: soil organic carbon stocks can bounce back to near forest levels when agroforests replace agriculture in southern India

NASA Astrophysics Data System (ADS)

Hombegowda, H. C.; van Straaten, O.; Köhler, M.; Hölscher, D.

2016-01-01

Tropical agroforestry has an enormous potential to sequester carbon while simultaneously producing agricultural yields and tree products. The amount of soil organic carbon (SOC) sequestered is influenced by the type of the agroforestry system established, the soil and climatic conditions, and management. In this regional-scale study, we utilized a chronosequence approach to investigate how SOC stocks changed when the original forests are converted to agriculture, and then subsequently to four different agroforestry systems (AFSs): home garden, coffee, coconut and mango. In total we established 224 plots in 56 plot clusters across 4 climate zones in southern India. Each plot cluster consisted of four plots: a natural forest reference, an agriculture reference and two of the same AFS types of two ages (30-60 years and > 60 years). The conversion of forest to agriculture resulted in a large loss the original SOC stock (50-61 %) in the top meter of soil depending on the climate zone. The establishment of home garden and coffee AFSs on agriculture land caused SOC stocks to rebound to near forest levels, while in mango and coconut AFSs the SOC stock increased only slightly above the agriculture SOC stock. The most important variable regulating SOC stocks and its changes was tree basal area, possibly indicative of organic matter inputs. Furthermore, climatic variables such as temperature and precipitation, and soil variables such as clay fraction and soil pH were likewise all important regulators of SOC and SOC stock changes. Lastly, we found a strong correlation between tree species diversity in home garden and coffee AFSs and SOC stocks, highlighting possibilities to increase carbon stocks by proper tree species assemblies.

On the rebound: soil organic carbon stocks can bounce back to near forest levels when agroforests replace agriculture in southern India

NASA Astrophysics Data System (ADS)

Hombegowda, H. C.; van Straaten, O.; Köhler, M.; Hölscher, D.

2015-08-01

Tropical agroforestry has an enormous potential to sequester carbon while simultaneously producing agricultural yields and tree products. The amount of soil organic carbon (SOC) sequestered is however influenced by the type of the agroforestry system established, the soil and climatic conditions and management. In this regional scale study, we utilized a chronosequence approach to investigate how SOC stocks changed when the original forests are converted to agriculture, and then subsequently to four different agroforestry systems (AFSs): homegarden, coffee, coconut and mango. In total we established 224 plots in 56 plot clusters across four climate zones in southern India. Each plot cluster consisted of four plots: a natural forest reference plot, an agriculture reference and two of the same AFS types of two ages (30-60 years and > 60 years). The conversion of forest to agriculture resulted in a large loss the original SOC stock (50-61 %) in the top meter of soil depending on the climate zone. The establishment of homegarden and coffee AFSs on agriculture land caused SOC stocks to rebound to near forest levels, while in mango and coconut AFSs the SOC stock increased only slightly above the agriculture stock. The most important variable regulating SOC stocks and its changes was tree basal area, possibly indicative of organic matter inputs. Furthermore, climatic variables such as temperature and precipitation, and soil variables such as clay fraction and soil pH were likewise all important regulators of SOC and SOC stock changes. Lastly, we found a strong correlation between tree species diversity in homegarden and coffee AFSs and SOC stocks, highlighting possibilities to increase carbon stocks by proper tree species assemblies.

Propellant Flow Actuated Piezoelectric Igniter for Combustion Engines

NASA Technical Reports Server (NTRS)

Wollen, Mark A. (Inventor)

2015-01-01

A propellant flow actuated piezoelectric igniter device using one or more hammer balls retained by one or more magnets, or other retaining method, until sufficient fluid pressure is achieved to release and accelerate the hammer ball, such that it impacts a piezoelectric crystal to produce an ignition spark. Certain preferred embodiments provide a means for repetitively capturing and releasing the hammer ball after it impacts one or more piezoelectric crystals, thereby oscillating and producing multiple, repetitive ignition sparks. Furthermore, an embodiment is presented for which oscillation of the hammer ball and repetitive impact to the piezoelectric crystal is maintained without the need for a magnet or other retaining mechanism to achieve this oscillating impact process.

Evidence for cultural differences between neighboring chimpanzee communities.

PubMed

Luncz, Lydia V; Mundry, Roger; Boesch, Christophe

2012-05-22

The majority of evidence for cultural behavior in animals has come from comparisons between populations separated by large geographical distances that often inhabit different environments. The difficulty of excluding ecological and genetic variation as potential explanations for observed behaviors has led some researchers to challenge the idea of animal culture. Chimpanzees (Pan troglodytes verus) in the Taï National Park, Côte d'Ivoire, crack Coula edulis nuts using stone and wooden hammers and tree root anvils. In this study, we compare for the first time hammer selection for nut cracking across three neighboring chimpanzee communities that live in the same forest habitat, which reduces the likelihood of ecological variation. Furthermore, the study communities experience frequent dispersal of females at maturity, which eliminates significant genetic variation. We compared key ecological factors, such as hammer availability and nut hardness, between the three neighboring communities and found striking differences in group-specific hammer selection among communities despite similar ecological conditions. Differences were found in the selection of hammer material and hammer size in response to changes in nut resistance over time. Our findings highlight the subtleties of cultural differences in wild chimpanzees and illustrate how cultural knowledge is able to shape behavior, creating differences among neighboring social groups. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hammer toe

MedlinePlus

... by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Toe Injuries and Disorders Read more NIH MedlinePlus ...

Kahn Bani Sa’ad Correctional Facility, Kahn Bani Sa’ad, Iraq

DTIC Science & Technology

2008-07-25

building (Building No. 07/03): 1. Ground floor columns were tested with a Schmidt hammer devise (measures the elastic properties or strength of...3. First floor columns – Schmidt hammer and ultrasonic tests were conducted on all the first floor columns. The test results showed the strength...Building Nos. 07/02 and 07/01): 1. Ground floor columns – Using a Schmidt hammer device, very few columns showed low strength. Further study and

Surface Collisions Involving Particles and Moisture (SCIP'M)

NASA Technical Reports Server (NTRS)

Davis, Robert H.

2005-01-01

Experiments were performed on the collision of a solid sphere with a nearly horizontal flat surface covered with a thin layer of viscous liquid. High-speed collisions were obtained by dropping the ball onto the surface from various heights, using gravitational acceleration. Low-speed collisions were obtained using pendulums with long strings or by launching the balls at low velocities in the reduced-gravity environment of parabolic flight. The sphere bounces only when the impact velocity exceeds a critical value. The coefficient of restitution (ratio of rebound velocity to impact velocity) increases with increasing impact velocity above the critical value, indicating the increasing relative importance of elastic deformation to viscous dissipation. The critical impact velocity increases, and the coefficient of restitution decreases, with increasing viscosity or thickness of the liquid layer and with decreasing density or size of the sphere. The ratio of the wet and dry coefficients is expressed as a function of the Stokes number (ratio of particle inertia and viscous forces), showing good agreement between theory and experiment. Similar experiments were performed with the flat surface inclined at various angles to the approaching sphere. A modified Stokes number, which is a measure of the ratio of inertia of the sphere in the normal direction to the viscous forces exerted by the fluid layer, was used for the analysis of oblique collisions. Even for these oblique collisions, it was found that no rebound of the ball was observed below a certain critical Stokes number. The coefficient of normal restitution, defined as a ratio of normal rebound velocity to normal approach velocity, was found to increase beyond the critical Stokes number and even out as it approaches the value for dry restitution at high Stokes numbers. It was also found that, for smooth spheres like steel, the normal restitution at the same modified Stokes number is independent of the angle of impact

Durability of viral suppression with first-line antiretroviral therapy in patients with HIV in the UK: an observational cohort study.

PubMed

O'Connor, Jemma; Smith, Colette; Lampe, Fiona C; Johnson, Margaret A; Chadwick, David R; Nelson, Mark; Dunn, David; Winston, Alan; Post, Frank A; Sabin, Caroline; Phillips, Andrew N

2017-07-01

The length of time that people with HIV on antiretroviral therapy (ART) with viral load suppression will be able to continue before developing viral rebound is unknown. We aimed to investigate the rate of first viral rebound in people that have achieved initial suppression with ART, to determine factors associated with viral rebound, and to use these estimates to predict long-term durability of viral suppression. The UK Collaborative HIV Cohort (UK CHIC) Study is an ongoing multicentre cohort study that brings together in a standardised format data on people with HIV attending clinics around the UK. We included participants who started ART with three or more drugs and who had achieved viral suppression (≤50 copies per mL) by 9 months after the start of ART (baseline). Viral rebound was defined as the first single viral load of more than 200 copies per mL or treatment interruption (for ≥1 month). We investigated factors associated with viral rebound with Poisson regression. These results were used to calculate the rate of viral rebound according to several key factors, including age, calendar year at start of ART, and time since baseline. Of the 16 101 people included, 4519 had a first viral rebound over 58 038 person-years (7·8 per 100 person-years, 95% CI 7·6-8·0). Of the 4519 viral rebounds, 3105 (69%) were defined by measurement of a single viral load of more than 200 copies per mL, and 1414 (31%) by a documented treatment interruption. The rate of first viral rebound declined substantially over time until 7 years from baseline. The other factors associated with viral rebound were current age at follow-up and calendar year at ART initiation (p<0·0001) and HIV risk group (p<0·0001); higher pre-ART CD4 count (p=0·0008) and pre-ART viral load (p=0·0003) were associated with viral rebound in the multivariate analysis only. For 1322 (29%) of the 3105 people with observed viral rebound, the next viral load value after rebound was 50 copies per mL or

10Be exposure age chronology of the last glaciation in the Krkonoše Mountains, Central Europe

NASA Astrophysics Data System (ADS)

Engel, Zbyněk; Braucher, Régis; Traczyk, Andrzej; Laetitia, Léanni; AsterTeam

2014-02-01

A new chronology of the last glaciation is established for the Krkonoše (Giant) Mountains, Central Europe, based on in-situ produced 10Be in moraine boulders. Exposure ages and Schmidt Hammer rebound values obtained for terminal moraines on the northern and southern flank of the mountains suggest that the oldest preserved moraines represent early phases of the Last Glacial Maximum (LGM). Large moraines at the outlet of the Snowy Cirques (Śnieżne Kotły) and in the middle part of the Úpa (Obří důl) trough were deposited around 21 ka while a series of smaller moraines above the LGM deposits represent readvances that occurred no later than 18.1 ± 0.6 ka, 15.7 ± 0.5 ka, 13.5 ± 0.5 ka and 12.9 ± 0.7 ka. An exposure age of 13.8 ± 0.4 ka obtained for protalus ramparts at the foot of the Úpská jáma Cirque headwall indicates that glaciers advanced only in north- to east-facing cirques during the Lateglacial. The last glacier fluctuation was synchronous with the Younger Dryas cold event. The timing of local glacier advances during the last glacial episode correlates with the late Weichselian glacier phases in the Alps and in the Bavarian/Bohemian Forest.

Rebounding from Tragedy

ERIC Educational Resources Information Center

Kennedy, Mike

2009-01-01

Some regions are prone to hurricanes, tornadoes, floods or earthquakes. Other tragedies, such as fires or acts of violence, can occur just about anywhere. Regardless of the specific type of disaster, schools and universities must be prepared to cope with crises that can disrupt operations, destroy facilities, and displace students and staff.…

Propellant Flow Actuated Piezoelectric Igniter for Combustion Engines

NASA Technical Reports Server (NTRS)

Wollen, Mark A. (Inventor)

2018-01-01

A propellant flow actuated piezoelectric igniter device using one or more hammer balls retained by one or more magnets, or other retaining method, until sufficient fluid pressure is achieved in one or more charging chambers to release and accelerate the hammer ball, such that it impacts a piezoelectric crystal to produce an ignition spark. Certain preferred embodiments provide a means for repetitively capturing and releasing the hammer ball after it impacts one or more piezoelectric crystals, thereby oscillating and producing multiple, repetitive ignition sparks. Furthermore, an embodiment is presented for which oscillation of the hammer ball and repetitive impact to the piezoelectric crystal is maintained without the need for a magnet or other retaining mechanism to achieve this oscillating impact process.

Cryptology Management in a Quantum Computing Era

DTIC Science & Technology

2012-06-01

HOW IT WORKS (BLACK BOX) ...........................7 1. Schrodinger’s Cat Theory ......................7 2. Multiverse Theory...the macroscopic scale of an animal through the mechanism of a hammer activated by the decay of the radioactive substance. 2. Multiverse Theory...quantum mechanics is the multiverse theory. This theory states that at every decision, the universe splits into multiple copies; the number of copies is

Dizziness in discus throwers is related to motion sickness generated while spinning.

PubMed

Perrin, P; Perrot, C; Deviterne, D; Ragaru, B; Kingma, H

2000-03-01

While both discus and hammer throwing involve rotating movements resulting in the throw of an object, discus throwers sometimes report dizziness, a condition never experienced by hammer throwers. We investigated whether this susceptibility was related to the sensitivity of the thrower or to the type of throwing achieved. For the latter, we compared the determining features of gesture, gaze stabilization and projectile trajectory in both sports. A total of 22 high-level sportsmen in these 2 disciplines, half of them practising both sports, were interviewed. Slow motion video recordings of discus and hammer throwing were examined to determine the visual referential, head movements and plantar surface support area involved at each stage of the motions. Discomfort was reported by 59% of the sportsmen while throwing discus, but by none while throwing hammer. Because several individuals practised both sports, these results exclude the hypothesis of individual susceptibility to dizziness. Video analysis evidenced that during hammer throwing, visual bearings can be used more easily than during discus throwing. Moreover, there is a loss of plantar afferents and generation of head movements liable to induce motion sickness, such as Coriolis acceleration. In conclusion, although hammer and discus-throwing present numerous similarities, we demonstrate here that crucial differences in the specific execution of each sport are responsible for the dizziness experienced by discus throwers.

Experimental Measurements and Mathematical Modeling of Static and Dynamic Characteristics of Water Flow in a Long Pipe

NASA Astrophysics Data System (ADS)

Jablonska, J.; Kozubkova, M.

2017-08-01

Static and dynamic characteristics of flow in technical practice are very important and serious problem and can be solved by experimental measurement or mathematical modeling. Unsteady flow presents time changes of the flow and water hammer can be an example of this phenomenon. Water hammer is caused by rapid changes in the water flow by means the closure or opening of the control valve. The authors deal with by hydraulic hammer at the multiphase flow (water and air), its one-dimensional modeling (Matlab SimHydraulics) and modeling with the use of the finite volume method (Ansys Fluent) in article. The circuit elements are defined by static and dynamic characteristics. The results are verified with measurements. The article evaluates different approaches, their advantages, disadvantages and specifics in solving of water hammer.

Time-Variable Gravity: The Low-Degree Components and their Connections with Geophysical/Climatic Changes

NASA Technical Reports Server (NTRS)

Cox, Christopher M.; Chao, Benjamin F.; Au, Andrew Y.

2004-01-01

The oblateness of the Earth's gravity field, J2, has long been observed to undergo a slight decrease due to post-glacial rebound of the mantle. Sometime around 1998 this trend reversed quite suddenly. This reversal persisted until 2001, at which point the atmosphere-corrected time series appears to have reversed yet again. Presently, the time series appears to be returning to the value that would nominally have been reached had the anomaly not occurred. This anomaly signifies a large interannual change in global mass distribution whose J2 effect overshadows that of the post-glacial rebound over such timescales. A number of possible causes have been considered, with oceanic mass redistribution as the leading candidate although other effects, such as glacial melting and core effects may be contributing.

Rebound of a coal tar creosote plume following partial source zone treatment with permanganate.

PubMed

Thomson, N R; Fraser, M J; Lamarche, C; Barker, J F; Forsey, S P

2008-11-14

indicated a highly variable and random spatial distribution of mass within the source zone and provided no insight into the mass removed of any of the monitored species. The down-gradient plume was monitored approximately 1, 2 and 4 years following treatment. The data collected at 1 and 2 years post-treatment showed a decrease in mass discharge (10 to 60%) and/or total plume mass (0 to 55%); however, by 4 years post-treatment there was a rebound in both mass discharge and total plume mass for all monitored compounds to pre-treatment values or higher. The variability of the data collected was too large to resolve subtle changes in plume morphology, particularly near the source zone, that would provide insight into the impact of the formation and deposition of manganese oxides that occurred during treatment on mass transfer and/or flow by-passing. Overall, the results from this pilot-scale investigation indicate that there was a significant but short-term (months) reduction of mass emanating from the source zone as a result of permanganate treatment but there was no long-term (years) impact on the ability of this coal tar creosote source zone to generate a multi-component plume.

Number Sense on the Number Line

ERIC Educational Resources Information Center

Woods, Dawn Marie; Ketterlin Geller, Leanne; Basaraba, Deni

2018-01-01

A strong foundation in early number concepts is critical for students' future success in mathematics. Research suggests that visual representations, like a number line, support students' development of number sense by helping them create a mental representation of the order and magnitude of numbers. In addition, explicitly sequencing instruction…

Higher Education: Approaches to Attract and Fund International Students in the United States and Abroad. Report to the Chairman, Subcommittee on International Organizations, Human Rights, and Oversight, Committee on Foreign Affairs, House of Representatives. GAO-09-379

ERIC Educational Resources Information Center

US Government Accountability Office, 2009

2009-01-01

Following September 11, 2001, the number of international students coming to the United States dropped for the first time in over 30 years. While enrollments have rebounded, the U.S. image has declined in the Muslim world and elsewhere. To improve global attitudes toward America, the U.S. government funds higher education for international…

Anthropogenic influences on the physical state of submicron particulate matter over a tropical forest

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

Bateman, Adam P.; Gong, Zhaoheng; Harder, Tristan H.

The occurrence of non-liquid and liquid physical states of submicron atmospheric particulate matter (PM) downwind of an urban region in central Amazonia was investigated. Measurements were conducted during two Intensive Operating Periods (IOP1 and IOP2) that took place during the wet and dry seasons, respectively, of the GoAmazon2014/5 campaign. Air masses representing variable influences of background conditions, urban pollution, and regional and continental scale biomass burning passed over the research site. As the air masses varied, particle rebound fraction, which is an indicator of the mix of physical states in a sampled particle population, was measured in real time atmore » ground level using an impactor apparatus. Micrographs collected by transmission electron microscopy confirmed that liquid particles adhered while non-liquid particles rebounded. Relative humidity (RH) was scanned to collect rebound curves. When the apparatus RH matched ambient RH, 95% of the particles were liquid as a campaign average, although this percentage dropped to as low as 60% during periods of anthropogenic influence. Secondary organic material, produced for the most part by the oxidation of volatile organic compounds emitted from the forest, was the largest source of liquid PM. Analyses of the mass spectra of the atmospheric PM by positive-matrix factorization (PMF) and of concentrations of carbon monoxide, total particle number, and oxides of nitrogen were used to identify time periods affected by anthropogenic influences, including both urban pollution and biomass burning. The occurrence of non-liquid PM correlated with these indicators of anthropogenic influence. A linear model having as output the rebound fraction and as input the PMF factor loadings explained up to 70% of the variance in the observed rebound fractions. Lastly, anthropogenic influences appear to favor non-liquid PM by providing molecular species that increase viscosity when internally mixed with

Anthropogenic influences on the physical state of submicron particulate matter over a tropical forest

DOE PAGES

Bateman, Adam P.; Gong, Zhaoheng; Harder, Tristan H.; ...

2016-08-17

The occurrence of non-liquid and liquid physical states of submicron atmospheric particulate matter (PM) downwind of an urban region in central Amazonia was investigated. Measurements were conducted during two Intensive Operating Periods (IOP1 and IOP2) that took place during the wet and dry seasons, respectively, of the GoAmazon2014/5 campaign. Air masses representing variable influences of background conditions, urban pollution, and regional and continental scale biomass burning passed over the research site. As the air masses varied, particle rebound fraction, which is an indicator of the mix of physical states in a sampled particle population, was measured in real time atmore » ground level using an impactor apparatus. Micrographs collected by transmission electron microscopy confirmed that liquid particles adhered while non-liquid particles rebounded. Relative humidity (RH) was scanned to collect rebound curves. When the apparatus RH matched ambient RH, 95% of the particles were liquid as a campaign average, although this percentage dropped to as low as 60% during periods of anthropogenic influence. Secondary organic material, produced for the most part by the oxidation of volatile organic compounds emitted from the forest, was the largest source of liquid PM. Analyses of the mass spectra of the atmospheric PM by positive-matrix factorization (PMF) and of concentrations of carbon monoxide, total particle number, and oxides of nitrogen were used to identify time periods affected by anthropogenic influences, including both urban pollution and biomass burning. The occurrence of non-liquid PM correlated with these indicators of anthropogenic influence. A linear model having as output the rebound fraction and as input the PMF factor loadings explained up to 70% of the variance in the observed rebound fractions. Lastly, anthropogenic influences appear to favor non-liquid PM by providing molecular species that increase viscosity when internally mixed with

Use of pile driving analysis for assessment of axial load capacity of piles : [technical summary].

DOT National Transportation Integrated Search

2012-01-01

The dynamic response of a pile during driving is very : complex, involving the interactions of the hammer, cushion, : pile and soil during application of an impact load. : The first analysis aimed at simulating a hammer blow on : a pile was published...

Reference guide for the soil compactor analyzer.

DOT National Transportation Integrated Search

2009-07-01

The Soil Compactor Analyzer (SCA) attaches to the automatic tamper used for Test Methods Tex-113-E and 114-E and uses rapid sampling of the hammer displacement to measure impact velocity. With the known mass of the hammer and the determined velocity,...

75 FR 67951 - Takes of Marine Mammals Incidental to Specified Activities; Piling and Structure Removal in...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-04

...), and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring and... vibratory hammer extraction methods and structures will be removed via cable lifting. In addition... be removed via vibratory hammer extraction methods. Operations will begin on the pilings and...

Fragmenting pastoral mobility: Changing grazing patterns in Post-Soviet Kazakhstan

Treesearch

Carol Kerven; Ilya Ilych Alimaev; Roy Behnke; Grant Davidson; Nurlan Malmakov; Aidos Smailov; Iain Wright

2006-01-01

Kazak nomads were seasonally mobile in the pre-Soviet period, in response to climate variability and landscape heterogeneity. The scale of these movements was interrupted during the Soviet period, but some degree of mobility remained. Mobility virtually ceased in the post-Soviet 1990s, but is reemerging as flock numbers rebound from the mid 1990s population crash.

Genetic Dissociation of Daily Sleep and Sleep Following Thermogenetic Sleep Deprivation in Drosophila.

PubMed

Dubowy, Christine; Moravcevic, Katarina; Yue, Zhifeng; Wan, Joy Y; Van Dongen, Hans P A; Sehgal, Amita

2016-05-01

Sleep rebound-the increase in sleep that follows sleep deprivation-is a hallmark of homeostatic sleep regulation that is conserved across the animal kingdom. However, both the mechanisms that underlie sleep rebound and its relationship to habitual daily sleep remain unclear. To address this, we developed an efficient thermogenetic method of inducing sleep deprivation in Drosophila that produces a substantial rebound, and applied the newly developed method to assess sleep rebound in a screen of 1,741 mutated lines. We used data generated by this screen to identify lines with reduced sleep rebound following thermogenetic sleep deprivation, and to probe the relationship between habitual sleep amount and sleep following thermogenetic sleep deprivation in Drosophila. To develop a thermogenetic method of sleep deprivation suitable for screening, we thermogenetically stimulated different populations of wake-promoting neurons labeled by Gal4 drivers. Sleep rebound following thermogenetically-induced wakefulness varies across the different sets of wake-promoting neurons that were stimulated, from very little to quite substantial. Thermogenetic activation of neurons marked by the c584-Gal4 driver produces both strong sleep loss and a substantial rebound that is more consistent within genotypes than rebound following mechanical or caffeine-induced sleep deprivation. We therefore used this driver to induce sleep deprivation in a screen of 1,741 mutagenized lines generated by the Drosophila Gene Disruption Project. Flies were subjected to 9 h of sleep deprivation during the dark period and released from sleep deprivation 3 h before lights-on. Recovery was measured over the 15 h following sleep deprivation. Following identification of lines with reduced sleep rebound, we characterized baseline sleep and sleep depth before and after sleep deprivation for these hits. We identified two lines that consistently exhibit a blunted increase in the duration and depth of sleep after

Dynamic Leidenfrost temperature on micro-textured surfaces: Acoustic wave absorption into thin vapor layer

NASA Astrophysics Data System (ADS)

Jerng, Dong Wook; Kim, Dong Eok

2018-01-01

The dynamic Leidenfrost phenomenon is governed by three types of pressure potentials induced via vapor hydrodynamics, liquid dynamic pressure, and the water hammer effect resulting from the generation of acoustic waves at the liquid-vapor interface. The prediction of the Leidenfrost temperature for a dynamic droplet needs quantitative evaluation and definition for each of the pressure fields. In particular, the textures on a heated surface can significantly affect the vapor hydrodynamics and the water hammer pressure. We present a quantitative model for evaluating the water hammer pressure on micro-textured surfaces taking into account the absorption of acoustic waves into the thin vapor layer. The model demonstrates that the strength of the acoustic flow into the liquid droplet, which directly contributes to the water hammer pressure, depends on the magnitude of the acoustic resistance (impedance) in the droplet and the vapor region. In consequence, the micro-textures of the surface and the increased spacing between them reduce the water hammer coefficient ( kh ) defined as the ratio of the acoustic flow into the droplet to total generated flow. Aided by numerical calculations that solve the laminar Navier-Stokes equation for the vapor flow, we also predict the dynamic Leidenfrost temperature on a micro-textured surface with reliable accuracy consistent with the experimental data.

The Mental Number Line in Dyscalculia: Impaired Number Sense or Access From Symbolic Numbers?

PubMed

Lafay, Anne; St-Pierre, Marie-Catherine; Macoir, Joël

Numbers may be manipulated and represented mentally over a compressible number line oriented from left to right. According to numerous studies, one of the primary reasons for dyscalculia is related to improper understanding of the mental number line. Children with dyscalculia usually show difficulty when they have to place Arabic numbers on a physical number line. However, it remains unclear whether they have a deficit with the mental number line per se or a deficit with accessing it from nonsymbolic and/or symbolic numbers. Quebec French-speaking 8- to 9-year-old children with (24) and without (37) dyscalculia were assessed with transcoding tasks ( number-to-position and position-to-number) designed to assess the acuity of the mental number line with Arabic and spoken numbers as well as with analogic numerosities. Results showed that children with dyscalculia produced a larger percentage absolute error than children without mathematics difficulties in every task except the number-to-position transcoding task with analogic numerosities. Hence, these results suggested that children with dyscalculia do not have a general deficit of the mental number line but rather a deficit with accessing it from symbolic numbers.

Assessing the Net Effects of Sanctions on the Proliferation of Weapons of Mass Destruction

DTIC Science & Technology

2012-12-01

354 Tabassum Zakaria and Caren Bohan, “Obama’s Olive Branch to Iran Turned into Sanctions Hammer,” Reuters, January...110 Zakaria , Tabassum and Caren Bohan, “Obama’s Olive Branch to Iran Turned into Sanctions Hammer,” Reuters, January 13, 2012, accessed on November

Influence of Kaolin in Fly Ash Based Geopolymer Concrete: Destructive and Non-Destructive Testing

NASA Astrophysics Data System (ADS)

Yahya, Z.; Abdullah, M. M. A. B.; Ramli, N. Mohd; Burduhos-Nergis, D. D.; Razak, R. Abd

2018-06-01

Development of geopolymer concrete is mainly to reduce the production of ordinary Portland cement (OPC) that adverse the natural effect. Fly ash is a by-product collected from electrical generating power plant which resulted from burning pulverized coal. Since fly ash is waste materials, it can be recycled for future advantages particularly as pozzolanic materials in construction industry. This study focused on the feasibility of fly ash based geopolymer concrete to which kaolin has been added. The main constituents of geopolymer production for this study were class F fly ash, sodium silicate and sodium hydroxide (NaOH) solution. The concentration of NaOH solution was fixed at 12 Molar, ratio of fly ash/alkaline activator and sodium silicate/NaOH fixed at 1.5 and 2.5, respectively. Kaolin was added in range 5% to 15% from the mass of fly ash and all the samples were cured at room temperature. Destructive and non-destructive test were performed on geopolymer concrete to evaluate the best mix proportions that yield the highest strength as well as the quality of the concrete. Compressive strength, flexural strength, rebound hammer and ultrasonic pulse velocity (UPV) result have been obtained. It shown that 5% replacement of kaolin contributed to maximum compressive strength and flexural strength of 40.4 MPa and 12.35 MPa at 28 days. These result was supported by non-destructive test for the same mix proportion.

DE-FOA-EE0005502 Advanced Percussive Drilling Technology for Geothermal Exploration and Development Phase II Report.

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

Su, Jiann-Cherng; Raymond, David W.; Prasad, Somuri V.

Percussive hammers are a promising advance in drilling technology for geothermal since they rely upon rock reduction mechanisms that are well-suited for use in the hard, brittle rock characteristic of geothermal formations. The project research approach and work plan includes a critical path to development of a high-temperature (HT) percussive hammer using a two- phase approach. The work completed in Phase I of the project demonstrated the viability of percussive hammers and that solutions to technical challenges in design, material technology, and performance are likely to be resolved. Work completed in Phase II focused on testing the findings from Phasemore » I and evaluating performance of the materials and designs at high- operating temperatures. A high-operating temperature (HOT) drilling facility was designed, built, and used to test the performance of the DTH under extreme conditions. Results from the testing indicate that a high-temperature capable hammer can be developed and is a viable alternative for user in the driller's toolbox.« less

Assessment of water pipes durability under pressure surge

NASA Astrophysics Data System (ADS)

Pham Ha, Hai; Minh, Lanh Pham Thi; Tang Van, Lam; Bulgakov, Boris; Bazhenova, Soafia

2017-10-01

Surge phenomenon occurs on the pipeline by the closing valve or pump suddenly lost power. Due to the complexity of the water hammer simulation, previous researches have only considered water hammer on the single pipe or calculation of some positions on water pipe network, it have not been analysis for all of pipe on the water distribution systems. Simulation of water hammer due to closing valve on water distribution system and the influence level of pressure surge is evaluated at the defects on pipe. Water hammer on water supply pipe network are simulated by Water HAMMER software academic version and the capacity of defects are calculated by SINTAP. SINTAP developed from Brite-Euram projects in Brussels-Belgium with the aim to develop a process for assessing the integrity of the structure for the European industry. Based on the principle of mechanical fault, indicating the size of defects in materials affect the load capacity of the product in the course of work, the process has proposed setting up the diagram to fatigue assessment defect (FAD). The methods are applied for water pipe networks of Lien Chieu district, Da Nang city, Viet Nam, the results show the affected area of wave pressure by closing the valve and thereby assess the greatest pressure surge effect to corroded pipe. The SINTAP standard and finite element mesh analysis at the defect during the occurrence of pressure surge which will accurately assess the bearing capacity of the old pipes. This is one of the bases to predict the leakage locations on the water distribution systems. Amount of water hammer when identified on the water supply networks are decreasing due to local losses at the nodes as well as the friction with pipe wall, so this paper adequately simulate water hammer phenomena applying for actual water distribution systems. The research verified that pipe wall with defect is damaged under the pressure surge value.

49 CFR 230.40 - Time and method of staybolt testing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... paragraph (a)(2) of this section. All staybolts also shall be hammer tested under hydrostatic pressure any time hydrostatic pressure above the MAWP specified on the boiler specification form (FRA Form No. 4... of hammer testing. If staybolts are tested while the boiler contains water, the hydrostatic pressure...

University of Maryland MRSEC - About Us: Committees

Science.gov Websites

; (we call this type of surface a vicinal surface). Modern scanned-probe microscopes, such as the STM Educational Education Pre-College Programs Homeschool Programs Undergraduate & Graduate Programs Teacher -2014 IRG 1 Donna Hammer Hammer, Donna MRSEC Associate Director & Director of Education Outreach

Hammer toe repair

MedlinePlus

... causing: Pain Irritation Sores Problems finding shoes that fit Skin infections Surgery may not be advised if: Treatment with paddings and strapping works You can still straighten your toe Changing to different shoe types can alleviate symptoms

Water Hammer Test

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Click on the image for the animation

This video shows the propulsion system on an engineering model of NASA's Phoenix Mars Lander being successfully tested. Instead of fuel, water is run through the propulsion system to make sure that the spacecraft holds up to vibrations caused by pressure oscillations.

The test was performed very early in the development of the mission, in 2005, at Lockheed Martin Space Systems, Denver. Early testing was possible because Phoenix's main structure was already in place from the 2001 Mars Surveyor program.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Interactions between cannabidiol and Δ9-THC following acute and repeated dosing: Rebound hyperactivity, sensorimotor gating and epigenetic and neuroadaptive changes in the mesolimbic pathway.

PubMed

Todd, Stephanie M; Zhou, Cilla; Clarke, David J; Chohan, Tariq W; Bahceci, Dilara; Arnold, Jonathon C

2017-02-01

The evidence base for the use of medical cannabis preparations containing specific ratios of cannabidiol (CBD) and Δ 9 -tetrahydrocannabinol (THC) is limited. While there is abundant data on acute interactions between CBD and THC, few studies have assessed the impact of their repeated co-administration. We previously reported that CBD inhibited or potentiated the acute effects of THC dependent on the measure being examined at a 1:1 CBD:THC dose ratio. Further, CBD decreased THC effects on brain regions involved in memory, anxiety and body temperature regulation. Here we extend on these finding by examining over 15 days of treatment whether CBD modulated the repeated effects of THC on behaviour and neuroadaption markers in the mesolimbic dopamine pathway. After acute locomotor suppression, repeated THC caused rebound locomotor hyperactivity that was modestly inhibited by CBD. CBD also slightly reduced the acute effects of THC on sensorimotor gating. These subtle effects were found at a 1:1 CBD:THC dose ratio but were not accentuated by a 5:1 dose ratio. CBD did not alter the trajectory of enduring THC-induced anxiety nor tolerance to the pharmacological effects of THC. There was no evidence of CBD potentiating the behavioural effects of THC. However we demonstrated for the first time that repeated co-administration of CBD and THC increased histone 3 acetylation (H3K9/14ac) in the VTA and ΔFosB expression in the nucleus accumbens. These changes suggest that while CBD may have protective effects acutely, its long-term molecular actions on the brain are more complex and may be supradditive. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

RATES OF FITNESS DECLINE AND REBOUND SUGGEST PERVASIVE EPISTASIS

PubMed Central

Perfeito, L; Sousa, A; Bataillon, T; Gordo, I

2014-01-01

Unraveling the factors that determine the rate of adaptation is a major question in evolutionary biology. One key parameter is the effect of a new mutation on fitness, which invariably depends on the environment and genetic background. The fate of a mutation also depends on population size, which determines the amount of drift it will experience. Here, we manipulate both population size and genotype composition and follow adaptation of 23 distinct Escherichia coli genotypes. These have previously accumulated mutations under intense genetic drift and encompass a substantial fitness variation. A simple rule is uncovered: the net fitness change is negatively correlated with the fitness of the genotype in which new mutations appear—a signature of epistasis. We find that Fisher's geometrical model can account for the observed patterns of fitness change and infer the parameters of this model that best fit the data, using Approximate Bayesian Computation. We estimate a genomic mutation rate of 0.01 per generation for fitness altering mutations, albeit with a large confidence interval, a mean fitness effect of mutations of −0.01, and an effective number of traits nine in mutS− E. coli. This framework can be extended to confront a broader range of models with data and test different classes of fitness landscape models. PMID:24372601

Use of impact testing to predict softness, cow preference, and hardening over time of stall bases.

PubMed

Fulwider, W K; Palmer, R W

2004-09-01

The objective of this study was to assess the softness and durability of commercially available free-stall bases, and to determine the relationship of stall base softness to cow preference. Clegg impact values were recorded at the University of Wisconsin-Madison Arlington Agricultural Research Station on June 19, 2002, and again on July 24, 2003. The Clegg Impact Soil Tester (model 95051, Lafayette Instruments, Lafayette, IN) with a 20-kg hammer was used in this study. The impact of the hammer on the free-stall base results in a digital display based on peak deceleration of the hammer's impact with the free-stall base in tens of gravities (CIV/H). The CIV/H value, as measured by the Clegg Impact hammer, is based on peak deceleration of the 20-kg hammer's impact with the surface, from a height of 30 cm. Clegg impact measures were highly correlated with cow preference measurements. This relationship suggests that Clegg impact measures of compressibility were good indicators for predicting stall-base acceptance. A cork mattress, 4 foam mattresses, 4 rubber mattresses, 4 rubber mats, and a waterbed were evaluated in this study. Foam-based mattresses lost cushioning ability faster than rubber mattresses or rubber mats. Clegg impact values increased over the 13-mo time period for most stall base types, which indicated a tendency of stall bases to harden.

Beyond Natural Numbers: Negative Number Representation in Parietal Cortex

PubMed Central

Blair, Kristen P.; Rosenberg-Lee, Miriam; Tsang, Jessica M.; Schwartz, Daniel L.; Menon, Vinod

2012-01-01

Unlike natural numbers, negative numbers do not have natural physical referents. How does the brain represent such abstract mathematical concepts? Two competing hypotheses regarding representational systems for negative numbers are a rule-based model, in which symbolic rules are applied to negative numbers to translate them into positive numbers when assessing magnitudes, and an expanded magnitude model, in which negative numbers have a distinct magnitude representation. Using an event-related functional magnetic resonance imaging design, we examined brain responses in 22 adults while they performed magnitude comparisons of negative and positive numbers that were quantitatively near (difference <4) or far apart (difference >6). Reaction times (RTs) for negative numbers were slower than positive numbers, and both showed a distance effect whereby near pairs took longer to compare. A network of parietal, frontal, and occipital regions were differentially engaged by negative numbers. Specifically, compared to positive numbers, negative number processing resulted in greater activation bilaterally in intraparietal sulcus (IPS), middle frontal gyrus, and inferior lateral occipital cortex. Representational similarity analysis revealed that neural responses in the IPS were more differentiated among positive numbers than among negative numbers, and greater differentiation among negative numbers was associated with faster RTs. Our findings indicate that despite negative numbers engaging the IPS more strongly, the underlying neural representation are less distinct than that of positive numbers. We discuss our findings in the context of the two theoretical models of negative number processing and demonstrate how multivariate approaches can provide novel insights into abstract number representation. PMID:22363276

Beyond natural numbers: negative number representation in parietal cortex.

PubMed

Blair, Kristen P; Rosenberg-Lee, Miriam; Tsang, Jessica M; Schwartz, Daniel L; Menon, Vinod

2012-01-01

Unlike natural numbers, negative numbers do not have natural physical referents. How does the brain represent such abstract mathematical concepts? Two competing hypotheses regarding representational systems for negative numbers are a rule-based model, in which symbolic rules are applied to negative numbers to translate them into positive numbers when assessing magnitudes, and an expanded magnitude model, in which negative numbers have a distinct magnitude representation. Using an event-related functional magnetic resonance imaging design, we examined brain responses in 22 adults while they performed magnitude comparisons of negative and positive numbers that were quantitatively near (difference <4) or far apart (difference >6). Reaction times (RTs) for negative numbers were slower than positive numbers, and both showed a distance effect whereby near pairs took longer to compare. A network of parietal, frontal, and occipital regions were differentially engaged by negative numbers. Specifically, compared to positive numbers, negative number processing resulted in greater activation bilaterally in intraparietal sulcus (IPS), middle frontal gyrus, and inferior lateral occipital cortex. Representational similarity analysis revealed that neural responses in the IPS were more differentiated among positive numbers than among negative numbers, and greater differentiation among negative numbers was associated with faster RTs. Our findings indicate that despite negative numbers engaging the IPS more strongly, the underlying neural representation are less distinct than that of positive numbers. We discuss our findings in the context of the two theoretical models of negative number processing and demonstrate how multivariate approaches can provide novel insights into abstract number representation.

The Mental Number Line in Dyscalculia: Impaired Number Sense or Access from Symbolic Numbers?

ERIC Educational Resources Information Center

Lafay, Anne; St-Pierre, Marie-Catherine; Macoir, Joël

2017-01-01

Numbers may be manipulated and represented mentally over a compressible number line oriented from left to right. According to numerous studies, one of the primary reasons for dyscalculia is related to improper understanding of the mental number line. Children with dyscalculia usually show difficulty when they have to place Arabic numbers on a…

Validation of a Laboratory Method for Evaluating Dynamic Properties of Reconstructed Equine Racetrack Surfaces

PubMed Central

Setterbo, Jacob J.; Chau, Anh; Fyhrie, Patricia B.; Hubbard, Mont; Upadhyaya, Shrini K.; Symons, Jennifer E.; Stover, Susan M.

2012-01-01

Background Racetrack surface is a risk factor for racehorse injuries and fatalities. Current research indicates that race surface mechanical properties may be influenced by material composition, moisture content, temperature, and maintenance. Race surface mechanical testing in a controlled laboratory setting would allow for objective evaluation of dynamic properties of surface and factors that affect surface behavior. Objective To develop a method for reconstruction of race surfaces in the laboratory and validate the method by comparison with racetrack measurements of dynamic surface properties. Methods Track-testing device (TTD) impact tests were conducted to simulate equine hoof impact on dirt and synthetic race surfaces; tests were performed both in situ (racetrack) and using laboratory reconstructions of harvested surface materials. Clegg Hammer in situ measurements were used to guide surface reconstruction in the laboratory. Dynamic surface properties were compared between in situ and laboratory settings. Relationships between racetrack TTD and Clegg Hammer measurements were analyzed using stepwise multiple linear regression. Results Most dynamic surface property setting differences (racetrack-laboratory) were small relative to surface material type differences (dirt-synthetic). Clegg Hammer measurements were more strongly correlated with TTD measurements on the synthetic surface than the dirt surface. On the dirt surface, Clegg Hammer decelerations were negatively correlated with TTD forces. Conclusions Laboratory reconstruction of racetrack surfaces guided by Clegg Hammer measurements yielded TTD impact measurements similar to in situ values. The negative correlation between TTD and Clegg Hammer measurements confirms the importance of instrument mass when drawing conclusions from testing results. Lighter impact devices may be less appropriate for assessing dynamic surface properties compared to testing equipment designed to simulate hoof impact (TTD

Parameterizing by the Number of Numbers

NASA Astrophysics Data System (ADS)

Fellows, Michael R.; Gaspers, Serge; Rosamond, Frances A.

The usefulness of parameterized algorithmics has often depended on what Niedermeier has called "the art of problem parameterization". In this paper we introduce and explore a novel but general form of parameterization: the number of numbers. Several classic numerical problems, such as Subset Sum, Partition, 3-Partition, Numerical 3-Dimensional Matching, and Numerical Matching with Target Sums, have multisets of integers as input. We initiate the study of parameterizing these problems by the number of distinct integers in the input. We rely on an FPT result for Integer Linear Programming Feasibility to show that all the above-mentioned problems are fixed-parameter tractable when parameterized in this way. In various applied settings, problem inputs often consist in part of multisets of integers or multisets of weighted objects (such as edges in a graph, or jobs to be scheduled). Such number-of-numbers parameterized problems often reduce to subproblems about transition systems of various kinds, parameterized by the size of the system description. We consider several core problems of this kind relevant to number-of-numbers parameterization. Our main hardness result considers the problem: given a non-deterministic Mealy machine M (a finite state automaton outputting a letter on each transition), an input word x, and a census requirement c for the output word specifying how many times each letter of the output alphabet should be written, decide whether there exists a computation of M reading x that outputs a word y that meets the requirement c. We show that this problem is hard for W[1]. If the question is whether there exists an input word x such that a computation of M on x outputs a word that meets c, the problem becomes fixed-parameter tractable.

Advanced Percussive Drilling Technology for Geothermal Exploration and Development

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

Su, Jiann; Raymond, David; Prasad, Somuri

Percussive hammers are a promising advance in drilling technology for geothermal since they rely upon rock reduction mechanisms that are well-suited for use in the hard, brittle rock characteristic of geothermal formations. The project research approach and work plan includes a critical path to development of a high-temperature (HT) percussive hammer using a two phase approach. The work completed in Phase I of the project demonstrated the viability of percussive hammers and that solutions to technical challenges in design, material technology, and performance are likely to be resolved. Work completed in Phase II focused on testing the findings from Phasemore » I and evaluating performance of the materials and designs at high operating temperatures. A high-operating temperature (HOT) drilling facility was designed, built, and used to test the performance of the DTH under extreme conditions. Results from the testing indicate that a high-temperature capable hammer can be developed and is a viable alternative for use in the driller’s toolbox.« less

Portable basketball rim testing device

DOEpatents

Abbott, W. Bruce; Davis, Karl C.

1993-01-01

A portable basketball rim rebound testing device 10 is illustrated in two preferred embodiments for testing the rebound or energy absorption characteristics of a basketball rim 12 and its accompanying support to determine likely rebound or energy absorption charcteristics of the system. The apparatus 10 includes a depending frame 28 having a C-clamp 36 for releasably rigidly connecting the frame to the basketball rim 12. A glide weight 60 is mounted on a guide rod 52 permitting the weight 60 to be dropped against a calibrated spring 56 held on an abutment surface on the rod to generate for deflecting the basketball rim and then rebounding the weight upwardly. A photosensor 66 is mounted on the depending frame 28 to sense passage of reflective surfaces 75 on the weight to thereby obtain sufficient data to enable a processing means 26 to calculate the rebound velocity and relate it to an energy absorption percentage rate of the rim system 12. A readout is provided to display the energy absorption percentage.

Mechanical Properties and Fatigue Behavior of Unitized Composite Airframe Structures at Elevated Temperature

DTIC Science & Technology

2014-03-27

created using a hammer and a punch tool provided by Material Test Systems (MTS) and were kept to a minimal depth to avoid fracture initiation at the...temperature. 76 be seen that the modulus remains relatively constant until near failure. There was no apparent correlation between modulus loss and...Normalized modulus vs. fatigue cycles of all ±45° specimens can be seen in Figure 56. There is not an evident correlation between number of cycles and

Energy efficiency, human behavior, and economic growth: Challenges to cutting energy demand to sustainable levels

NASA Astrophysics Data System (ADS)

Santarius, Tilman

2015-03-01

Increasing energy efficiency in households, transportation, industries, and services is an important strategy to reduce energy service demand to levels that allow the steep reduction of greenhouse gases, and a full fledged switch of energy systems to a renewable basis. Yet, technological efficiency improvements may generate so-called rebound effects, which may `eat up' parts of the technical savings potential. This article provides a comprehensive review of existing research on these effects, raises critiques, and points out open questions. It introduces micro-economic rebound effect and suggests extending consumer-side analysis to incorporate potential `psychological rebound effects.' It then discusses meso-economic rebound effects, i.e. producer-side and market-level rebounds, which so far have achieved little attention in the literature. Finally, the article critically reviews evidence for macro-economic rebound effects as energy efficiency-induced economic growth impacts. For all three categories, the article summarizes assessments of their potential quantitative scope, while pointing out remaining methodological weaknesses and open questions. As a rough "rule of thumb", in the long term and on gross average, only half the technical savings potential of across-the-board efficiency improvements may actually be achieved in the real world. Policies that aim at cutting energy service demand to sustainable levels are well advised to take due note of detrimental behavioral and economic growth impacts, and should foster policies and measures that can contain them.

Selected properties of particleboard panels manufactured from rice straws of different geometries

Treesearch

Xianjun Li; Zhiyong Cai; Jerrold E. Winandy; Altaf H. Basta

2010-01-01

The objective is to evaluate the primary mechanical and physical properties of particleboard made from hammer-milled rice straw particles of six different categories and two types of resins. The results show the performance of straw particleboards is highly dependent upon the straw particle size controlled by the opening size of the perforated plate inside the hammer-...

7 CFR 29.9205 - Identification number (farm serial number).

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Identification number (farm serial number). 29.9205 Section 29.9205 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... number (farm serial number). The serial number assigned to an individual farm by the appropriate office...

7 CFR 29.9205 - Identification number (farm serial number).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Identification number (farm serial number). 29.9205 Section 29.9205 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... number (farm serial number). The serial number assigned to an individual farm by the appropriate office...

7 CFR 29.9205 - Identification number (farm serial number).

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Identification number (farm serial number). 29.9205 Section 29.9205 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... number (farm serial number). The serial number assigned to an individual farm by the appropriate office...

7 CFR 29.9205 - Identification number (farm serial number).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Identification number (farm serial number). 29.9205 Section 29.9205 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... number (farm serial number). The serial number assigned to an individual farm by the appropriate office...

7 CFR 29.9205 - Identification number (farm serial number).

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Identification number (farm serial number). 29.9205 Section 29.9205 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... number (farm serial number). The serial number assigned to an individual farm by the appropriate office...

Genetic Dissociation of Daily Sleep and Sleep Following Thermogenetic Sleep Deprivation in Drosophila

PubMed Central

Dubowy, Christine; Moravcevic, Katarina; Yue, Zhifeng; Wan, Joy Y.; Van Dongen, Hans P.A.; Sehgal, Amita

2016-01-01

Study Objectives: Sleep rebound—the increase in sleep that follows sleep deprivation—is a hallmark of homeostatic sleep regulation that is conserved across the animal kingdom. However, both the mechanisms that underlie sleep rebound and its relationship to habitual daily sleep remain unclear. To address this, we developed an efficient thermogenetic method of inducing sleep deprivation in Drosophila that produces a substantial rebound, and applied the newly developed method to assess sleep rebound in a screen of 1,741 mutated lines. We used data generated by this screen to identify lines with reduced sleep rebound following thermogenetic sleep deprivation, and to probe the relationship between habitual sleep amount and sleep following thermogenetic sleep deprivation in Drosophila. Methods: To develop a thermogenetic method of sleep deprivation suitable for screening, we thermogenetically stimulated different populations of wake-promoting neurons labeled by Gal4 drivers. Sleep rebound following thermogenetically-induced wakefulness varies across the different sets of wake-promoting neurons that were stimulated, from very little to quite substantial. Thermogenetic activation of neurons marked by the c584-Gal4 driver produces both strong sleep loss and a substantial rebound that is more consistent within genotypes than rebound following mechanical or caffeine-induced sleep deprivation. We therefore used this driver to induce sleep deprivation in a screen of 1,741 mutagenized lines generated by the Drosophila Gene Disruption Project. Flies were subjected to 9 h of sleep deprivation during the dark period and released from sleep deprivation 3 h before lights-on. Recovery was measured over the 15 h following sleep deprivation. Following identification of lines with reduced sleep rebound, we characterized baseline sleep and sleep depth before and after sleep deprivation for these hits. Results: We identified two lines that consistently exhibit a blunted increase in the

Alternative Fuels Data Center: Maps and Data

Science.gov Websites

reduced AFV acquisition requirements. However, overall AFV acquisitions have since rebounded to pre-Great acquisitions have since rebounded to pre-Great Recession levels. Share Embed Share Copy and share this link

Number sense in the transition from natural to rational numbers.

PubMed

Van Hoof, Jo; Verschaffel, Lieven; Van Dooren, Wim

2017-03-01

Rational numbers are of critical importance both in mathematics and in other fields of science. However, they form a stumbling block for learners. One widely known source of the difficulty learners have with rational numbers is the natural number bias, that is the tendency to (inappropriately) apply natural number properties in rational number tasks. Still, it has been shown that a good understanding of natural numbers is highly predictive for mathematics achievement in general, and for performance on rational number tasks in particular. In this study, we further investigated the relation between learners' natural and rational number knowledge, specifically in cases where a natural number bias may lead to errors. Participants were 140 sixth graders from six different primary schools. Participants completed a symbolic and a non-symbolic natural number comparison task, a number line estimation task, and a rational number sense test. Learners' natural number knowledge was found to be a good predictor of their rational number knowledge. However, after first controlling for learners' general mathematics achievement, their natural number knowledge only predicted the subaspect of operations with rational numbers. The results of this study suggest that the relation between learners' natural and rational number knowledge can largely be explained by their relation with learners' general mathematics achievement. © 2016 The British Psychological Society.

Numerical Investigation of Rockfall Impacts on Muckpiles for Underground Portals

NASA Astrophysics Data System (ADS)

Effeindzourou, Anna; Giacomini, Anna; Thoeni, Klaus; Sloan, Scott W.

2017-06-01

Small-scale waste rock piles or muckpiles are commonly used as energy absorption barriers in various surface mining applications. This paper numerically investigates the impact behaviour of blocks on muckpiles used as cushion layer on top of underground portal entries. A three-dimensional discrete element model is implemented into the open-source framework YADE and validated using full-scale experimental data. The model allows estimating the energy absorption capacity of the muckpile and the impact forces acting on the portal structure. It also provides valuable information on the rebound characteristics which are useful for the definition of the potential safety areas in the vicinity of an underground entry. In order to show its capabilities, the model is applied to a large number of cases representing potential design conditions. The influence of block mass, impact velocity and absorbing cushion thickness on the forces at the base of the muckpile and the rebound trajectories after impact are investigated.

Entrainment of solid particles over irregular wavy walls

NASA Astrophysics Data System (ADS)

Milici, Barbara

2017-11-01

The distribution of inertial particles in turbulent flows is highly nonuniform and is governed by the dynamics of turbulent structures of the underlying carrier flow field which, in turn, is affected by the presence of a loading of dispersed particles. The issue is discussed here focusing on the coupling between near-bed coherent structures and suspended solid particles dynamics, in wall-bounded turbulent multiphase flows, bounded by rough boundaries. The friction Reynolds number of the unladen flow is Reτ=180 and the dispersed phase spans one order of magnitude of particle diameter. The analysis takes into account fluid-particle interaction (two-way coupling) in the frame of the Particle-Source-In-Cell (PSIC) method, using Direct Numerical Simulations (DNS) for the carrier phase coupled with Lagrangian Particle Tracking (LPT) for the dispersed phase. The effect of the wall's roughness is taken into account modelling the elastic rebound of particles onto it, instead of using a virtual rebound model.

Approximate Number Sense, Symbolic Number Processing, or Number-Space Mappings: What Underlies Mathematics Achievement?

ERIC Educational Resources Information Center

Sasanguie, Delphine; Gobel, Silke M.; Moll, Kristina; Smets, Karolien; Reynvoet, Bert

2013-01-01

In this study, the performance of typically developing 6- to 8-year-old children on an approximate number discrimination task, a symbolic comparison task, and a symbolic and nonsymbolic number line estimation task was examined. For the first time, children's performances on these basic cognitive number processing tasks were explicitly contrasted…

Benefit from NASA

NASA Image and Video Library

2004-04-15

During the Apollo era Marshall Space Flight Center's engineers developed the Magnetomotive Hammer to remove distortions from Saturn V bulkhead gore segments. Using an intense magnetic field, the Hammer removed manufacturing distortions from rejected segments which otherwise would have been discarded at a cost of $30,000 each. Various automobile, ship and aircraft manufacturers adoped the technology for commercial use.

An automated data collection system for a Charpy impact tester

NASA Technical Reports Server (NTRS)

Weigman, Bernard J.; Spiegel, F. Xavier

1993-01-01

A method for automated data collection has been developed for a Charpy impact tester. A potentiometer is connected to the pivot point of the hammer and measures the angular displacement of the hammer. This data is collected with a computer and, through appropriate software, accurately records the energy absorbed by the specimen. The device can be easily calibrated with minimal effort.

Energy efficiency, human behavior, and economic growth: Challenges to cutting energy demand to sustainable levels

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

Santarius, Tilman, E-mail: tilman@santarius.de

Increasing energy efficiency in households, transportation, industries, and services is an important strategy to reduce energy service demand to levels that allow the steep reduction of greenhouse gases, and a full fledged switch of energy systems to a renewable basis. Yet, technological efficiency improvements may generate so-called rebound effects, which may ‘eat up’ parts of the technical savings potential. This article provides a comprehensive review of existing research on these effects, raises critiques, and points out open questions. It introduces micro-economic rebound effect and suggests extending consumer-side analysis to incorporate potential ‘psychological rebound effects.’ It then discusses meso-economic rebound effects,more » i.e. producer-side and market-level rebounds, which so far have achieved little attention in the literature. Finally, the article critically reviews evidence for macro-economic rebound effects as energy efficiency-induced economic growth impacts. For all three categories, the article summarizes assessments of their potential quantitative scope, while pointing out remaining methodological weaknesses and open questions. As a rough “rule of thumb”, in the long term and on gross average, only half the technical savings potential of across-the-board efficiency improvements may actually be achieved in the real world. Policies that aim at cutting energy service demand to sustainable levels are well advised to take due note of detrimental behavioral and economic growth impacts, and should foster policies and measures that can contain them.« less

The use of the durometer to measure rock hardness in geomorphology. Advantages and limitations.

NASA Astrophysics Data System (ADS)

Feal-Pérez, Alejandra; Blanco-Chao, Ramón; Valcarcel-Díaz, Marcos; Combes, Martín. A.

2010-05-01

The durometer is a hardness tester developed to measure hardness of metallic materials that has been recently introduced to measure rock hardness in weathering studies. Aoki & Matsukura (2007) highlight some advantages of the durometer compared with the Schmidt Rock Test Hammer: the smaller plunge allows measurements in small surfaces such as taffoni or rock carvings, the wider measurement range and the lower impact energy. This last makes it a non destructive method that can be used on relatively soft rocks. In this work the durometer Equotip (©) has been tested in different environments in the field and in the laboratory to explore its applicability and limitations. We applied the device on small rock samples of granite and limestone and a T-test showed that smaller sample size gave smaller hardness values (p < 0.01). Testing the effects of water content, there were no statistically significant differences between water saturated and dry samples. The influence of rock surface roughness was evaluated applying the durometer in ancient rock carvings in medium to coarse grain granites. We compared the values obtained inside and outside the grooves of the carvings using two different support rings, one flat and one concave. The flat ring was not able to reach the bottom of the groove, meanwhile the concave ring adjusts fairly well given its semi spherical section. A t-test confirmed the difference (p < 0.01) between lower rebound values obtained in the grooves using the flat ring and the higher and less scattered values obtained when the concave ring is used. As a very sensitive device, there are some problems in the use related with rock roughness and rock grain size. In weathered medium to coarse grained rocks, with very irregular surfaces, is not easy to get a good contact between the plunge and the rock surface. A poor contact caused by surface roughness causes the scattering and lowering of rebound values. On the contrary, in homogeneous fine grained rocks and

Natural Number Bias in Operations with Missing Numbers

ERIC Educational Resources Information Center

Christou, Konstantinos P.

2015-01-01

This study investigates the hypothesis that there is a natural number bias that influences how students understand the effects of arithmetical operations involving both Arabic numerals and numbers that are represented by symbols for missing numbers. It also investigates whether this bias correlates with other aspects of students' understanding of…

Dietary Prebiotics and Bioactive Milk Fractions Improve NREM Sleep, Enhance REM Sleep Rebound and Attenuate the Stress-Induced Decrease in Diurnal Temperature and Gut Microbial Alpha Diversity

PubMed Central

Thompson, Robert S.; Roller, Rachel; Mika, Agnieszka; Greenwood, Benjamin N.; Knight, Rob; Chichlowski, Maciej; Berg, Brian M.; Fleshner, Monika

2017-01-01

Severe, repeated or chronic stress produces negative health outcomes including disruptions of the sleep/wake cycle and gut microbial dysbiosis. Diets rich in prebiotics and glycoproteins impact the gut microbiota and may increase gut microbial species that reduce the impact of stress. This experiment tested the hypothesis that consumption of dietary prebiotics, lactoferrin (Lf) and milk fat globule membrane (MFGM) will reduce the negative physiological impacts of stress. Male F344 rats, postnatal day (PND) 24, received a diet with prebiotics, Lf and MFGM (test) or a calorically matched control diet. Fecal samples were collected on PND 35/70/91 for 16S rRNA sequencing to examine microbial composition and, in a subset of rats; Lactobacillus rhamnosus was measured using selective culture. On PND 59, biotelemetry devices were implanted to record sleep/wake electroencephalographic (EEG). Rats were exposed to an acute stressor (100, 1.5 mA, tail shocks) on PND 87 and recordings continued until PND 94. Test diet, compared to control diet, increased fecal Lactobacillus rhamnosus colony forming units (CFU), facilitated non-rapid eye movement (NREM) sleep consolidation (PND 71/72) and enhanced rapid eye movement (REM) sleep rebound after stressor exposure (PND 87). Rats fed control diet had stress-induced reductions in alpha diversity and diurnal amplitude of temperature, which were attenuated by the test diet (PND 91). Stepwise multiple regression analysis revealed a significant linear relationship between early-life Deferribacteres (PND 35) and longer NREM sleep episodes (PND 71/72). A diet containing prebiotics, Lf and MFGM enhanced sleep quality, which was related to changes in gut bacteria and modulated the impact of stress on sleep, diurnal rhythms and the gut microbiota. PMID:28119579

Differences in game-related statistics of basketball performance by game location for men's winning and losing teams.

PubMed

Gómez, Miguel A; Lorenzo, Alberto; Barakat, Rubén; Ortega, Enrique; Palao, José M

2008-02-01

The aim of the present study was to identify game-related statistics that differentiate winning and losing teams according to game location. The sample included 306 games of the 2004-2005 regular season of the Spanish professional men's league (ACB League). The independent variables were game location (home or away) and game result (win or loss). The game-related statistics registered were free throws (successful and unsuccessful), 2- and 3-point field goals (successful and unsuccessful), offensive and defensive rebounds, blocks, assists, fouls, steals, and turnovers. Descriptive and inferential analyses were done (one-way analysis of variance and discriminate analysis). The multivariate analysis showed that winning teams differ from losing teams in defensive rebounds (SC = .42) and in assists (SC = .38). Similarly, winning teams differ from losing teams when they play at home in defensive rebounds (SC = .40) and in assists (SC = .41). On the other hand, winning teams differ from losing teams when they play away in defensive rebounds (SC = .44), assists (SC = .30), successful 2-point field goals (SC = .31), and unsuccessful 3-point field goals (SC = -.35). Defensive rebounds and assists were the only game-related statistics common to all three analyses.

Simulation of systems for shock wave/compression waves damping in technological plants

NASA Astrophysics Data System (ADS)

Sumskoi, S. I.; Sverchkov, A. M.; Lisanov, M. V.; Egorov, A. F.

2016-09-01

At work of pipeline systems, flow velocity decrease can take place in the pipeline as a result of the pumps stop, the valves shutdown. As a result, compression waves appear in the pipeline systems. These waves can propagate in the pipeline system, leading to its destruction. This phenomenon is called water hammer (water hammer flow). The most dangerous situations occur when the flow is stopped quickly. Such urgent flow cutoff often takes place in an emergency situation when liquid hydrocarbons are being loaded into sea tankers. To prevent environment pollution it is necessary to stop the hydrocarbon loading urgently. The flow in this case is cut off within few seconds. To prevent an increase in pressure in a pipeline system during water hammer flow, special protective systems (pressure relief systems) are installed. The approaches to systems of protection against water hammer (pressure relief systems) modeling are described in this paper. A model of certain pressure relief system is considered. It is shown that in case of an increase in the intensity of hydrocarbons loading at a sea tanker, presence of the pressure relief system allows to organize safe mode of loading.

A Study for the Restoration of Hong Dae-Yong Honsangui - Focusing on the structure and operating mechanism

NASA Astrophysics Data System (ADS)

Lee, Yong Sam; Kim, Sang Hyuk; Park, Je Hoon

2013-09-01

Honsangui (celestial globe) which is a water-hammering method astronomical clock is recorded in "Juhaesuyong" which is Volume VI of supplement from "Damheonseo", written by Hong Dae-Yong (1731~1783). We made out the conceptual design of Hong Dae-Yong's Honsangui through the study on its structure and working mechanism. Honsangui consist of three rings and two layers, the structure of rings which correspond to outer layer is similar to his own Tongcheonui (armillary sphere) which is a kind of armillary sphere. Honsang sphere which correspond to inner layer depicts constellations and milky way and two beads hang on it as Sun and Moon respectively for realize the celestial motion. Tongcheonui is operated by the pendulum power but Honsangui is operated by water-hammering method mechanism. This Honsangui's working mechanism is the traditional way of Joseon and it was simplified the working mechanism of Shui y'n i hsiang t'ai which is a representative astronomical clock of China. This record of Honsangui is the only historical record about the water-hammering method working mechanism of Joseon Era and it provide the study of water-hammering method mechanism with a vital clue.

An autonomous unmanned aerial vehicle sensing system for structural health monitoring of bridges

NASA Astrophysics Data System (ADS)

Reagan, Daniel; Sabato, Alessandro; Niezrecki, Christopher; Yu, Tzuyang; Wilson, Richard

2016-04-01

As civil infrastructure (i.e. bridges, railways, and tunnels) continues to age; the frequency and need to perform inspection more quickly on a broader scale increases. Traditional inspection and monitoring techniques (e.g., visual inspection, mechanical sounding, rebound hammer, cover meter, electrical potential measurements, ultrasound, and ground penetrating radar) may produce inconsistent results, require lane closure, are labor intensive and time-consuming. Therefore, new structural health monitoring systems must be developed that are automated, highly accurate, minimally invasive, and cost effective. Three-dimensional (3D) digital image correlation (DIC) systems have the merits of extracting full-field strain, deformation, and geometry profiles. These profiles can then be stitched together to generate a complete integrity map of the area of interest. Concurrently, unmanned aerial vehicles (UAVs) have emerged as valuable resources for positioning sensing equipment where it is either difficult to measure or poses a risk to human safety. UAVs have the capability to expedite the optical-based measurement process, offer increased accessibility, and reduce interference with local traffic. Within this work, an autonomous unmanned aerial vehicle in conjunction with 3D DIC was developed for monitoring bridges. The capabilities of the proposed system are demonstrated in both laboratory measurements and data collected from bridges currently in service. Potential measurement influences from platform instability, rotor vibration and positioning inaccuracy are also studied in a controlled environment. The results of these experiments show that the combination of autonomous flight with 3D DIC and other non-contact measurement systems provides a valuable and effective civil inspection platform.

The HAMMER: High altitude multiple mission environmental researcher

NASA Technical Reports Server (NTRS)

Hayashi, Darren; Zylla, Cara; Amaro, Ernesto; Colin, Phil; Klause, Thomas; Lopez, Bernardo; Williamson, Danna

1991-01-01

At the equator, the ozone layer ranges from 65,000 to 130,000+ feet which is beyond the capabilities of the ER-2, NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozone layer at the equator. This aircraft must be able to satisfy four mission profiles. Mission one is a polar mission which ranges from Chile to the South Pole and back to Chile, a total range of 6000 n. mi. at 100,000 feet with a 2500 lb. payload. The second mission is also a polar mission with a decreased altitude of 70,000 feet and an increased payload of 4000 lb. For the third mission, the aircraft will take-off at NASA Ames, cruise at 100,000 feet carrying a 2500 lb. payload, and land in Puerto Montt, Chile. The final mission requires the aircraft to take-off at NASA Ames, cruise at 100,000 feet with a 1000 lb. payload, make an excursion to 120,000 feet, and land at Howard AFB, Panama. All three missions require that a subsonic Mach number is maintained due to constraints imposed by the air sampling equipment. The aircraft need not be manned for all four missions. Three aircraft configurations were determined to be the most suitable for meeting the above requirements. The performance of each configuration is analyzed to investigate the feasibility of the project requirements. In the event that a requirement can not be obtained within the given constraints, recommendations for proposal modifications are given.

Shock-induced nanobubble collapse and its applications

NASA Astrophysics Data System (ADS)

Vedadi, Mohammad Hossein

The shock-induced collapse of nanobubbles in water is investigated using molecular dynamics simulations based on a reactive force field. Monitoring the collapse of a cavitation nanobubble, we observe a focused nanojet at the onset of bubble shrinkage and a water hammer shock wave upon bubble collapse. The nanojet length scales linearly with the nanobubble radius, as observed in experiments on micron-to-millimeter size bubbles. The shock induces dramatic structural changes, including an ice-VII-like structural motif at a particle velocity of approximately 1 km/s. The incipient ice VII formation and the calculated Hugoniot curve are in good agreement with experimental results. Moreover, a substantial number of positive and negative ions appear when the nanojet hits the distal side of the nanobubble and the water hammer shock forms. Furthermore, two promising applications of shock-induced nanobubble collapse have been explored. Our simulations of poration in lipid bilayers due to shock-induced collapse of nanobubbles reveal penetration of nanojets into lipid bilayers. The nanojet impact generates shear flow of water on bilayer leaflets and pressure gradients across them, which transiently enhance the bilayer permeability by creating nanopores through which water molecules translocate across the bilayer. The effects of nanobubble size and temperature on the porosity of lipid bilayers are examined. Finally, the shock-induced collapse of CO2-filled nanobubbles in water is investigated. The energetic nanojet and high-pressure water hammer shock formed during and after collapse of the nanobubble trigger mechano-chemical H2O-CO2 reactions, some of which lead to splitting of water molecules. The dominant pathways through which splitting of water molecules occur are identified.

Performance Characteristics and Accuracy in Perceptual Discrimination of Leather and Synthetic Basketballs.

ERIC Educational Resources Information Center

Mathes, Sharon; Flatten, Kay

1982-01-01

To assess the performance characteristics of synthetic and leather basketballs, individuals were asked to discriminate perceptually between the leather and synthetic basketballs under four treatment conditions. Rebound characteristics on five playing surfaces were measured. Leather basketballs rebounded significantly higher; no significant…

Assessing the Underwater Acoustics of the World's Largest Vibration Hammer (OCTA-KONG) and Its Potential Effects on the Indo-Pacific Humpbacked Dolphin (Sousa chinensis)

PubMed Central

Wang, Zhitao; Wu, Yuping; Duan, Guoqin; Cao, Hanjiang; Liu, Jianchang; Wang, Kexiong; Wang, Ding

2014-01-01

Anthropogenic noise in aquatic environments is a worldwide concern due to its potential adverse effects on the environment and aquatic life. The Hongkong-Zhuhai-Macao Bridge is currently under construction in the Pearl River Estuary, a hot spot for the Indo-Pacific humpbacked dolphin (Sousa chinensis) in China. The OCTA-KONG, the world's largest vibration hammer, is being used during this construction project to drive or extract steel shell piles 22 m in diameter. This activity poses a substantial threat to marine mammals, and an environmental assessment is critically needed. The underwater acoustic properties of the OCTA-KONG were analyzed, and the potential impacts of the underwater acoustic energy on Sousa, including auditory masking and physiological impacts, were assessed. The fundamental frequency of the OCTA-KONG vibration ranged from 15 Hz to 16 Hz, and the noise increments were below 20 kHz, with a dominant frequency and energy below 10 kHz. The resulting sounds are most likely detectable by Sousa over distances of up to 3.5 km from the source. Although Sousa clicks do not appear to be adversely affected, Sousa whistles are susceptible to auditory masking, which may negatively impact this species' social life. Therefore, a safety zone with a radius of 500 m is proposed. Although the zero-to-peak source level (SL) of the OCTA-KONG was lower than the physiological damage level, the maximum root-mean-square SL exceeded the cetacean safety exposure level on several occasions. Moreover, the majority of the unweighted cumulative source sound exposure levels (SSELs) and the cetacean auditory weighted cumulative SSELs exceeded the acoustic threshold levels for the onset of temporary threshold shift, a type of potentially recoverable auditory damage resulting from prolonged sound exposure. These findings may aid in the identification and design of appropriate mitigation methods, such as the use of air bubble curtains, “soft start” and “power down�

Assessing the underwater acoustics of the world's largest vibration hammer (OCTA-KONG) and its potential effects on the Indo-Pacific humpbacked dolphin (Sousa chinensis).

PubMed

Wang, Zhitao; Wu, Yuping; Duan, Guoqin; Cao, Hanjiang; Liu, Jianchang; Wang, Kexiong; Wang, Ding

2014-01-01

Anthropogenic noise in aquatic environments is a worldwide concern due to its potential adverse effects on the environment and aquatic life. The Hongkong-Zhuhai-Macao Bridge is currently under construction in the Pearl River Estuary, a hot spot for the Indo-Pacific humpbacked dolphin (Sousa chinensis) in China. The OCTA-KONG, the world's largest vibration hammer, is being used during this construction project to drive or extract steel shell piles 22 m in diameter. This activity poses a substantial threat to marine mammals, and an environmental assessment is critically needed. The underwater acoustic properties of the OCTA-KONG were analyzed, and the potential impacts of the underwater acoustic energy on Sousa, including auditory masking and physiological impacts, were assessed. The fundamental frequency of the OCTA-KONG vibration ranged from 15 Hz to 16 Hz, and the noise increments were below 20 kHz, with a dominant frequency and energy below 10 kHz. The resulting sounds are most likely detectable by Sousa over distances of up to 3.5 km from the source. Although Sousa clicks do not appear to be adversely affected, Sousa whistles are susceptible to auditory masking, which may negatively impact this species' social life. Therefore, a safety zone with a radius of 500 m is proposed. Although the zero-to-peak source level (SL) of the OCTA-KONG was lower than the physiological damage level, the maximum root-mean-square SL exceeded the cetacean safety exposure level on several occasions. Moreover, the majority of the unweighted cumulative source sound exposure levels (SSELs) and the cetacean auditory weighted cumulative SSELs exceeded the acoustic threshold levels for the onset of temporary threshold shift, a type of potentially recoverable auditory damage resulting from prolonged sound exposure. These findings may aid in the identification and design of appropriate mitigation methods, such as the use of air bubble curtains, "soft start" and "power down" techniques.

Quality Assurance for Rapid Airfield Construction

DTIC Science & Technology

2008-05-01

necessary to conduct a volume-replacement density test for in-place soil. This density test, which was developed during this investigation, involves...the test both simpler and quicker. The Clegg hammer results are the primary means of judging compaction; thus, the requirements for density tests are...minimized through a stepwise acceptance procedure. Statistical criteria for evaluating Clegg hammer and density measurements are also included

Influence of solidification on the impact of supercooled water drops onto cold surfaces

NASA Astrophysics Data System (ADS)

Li, Hai; Roisman, Ilia V.; Tropea, Cameron

2015-06-01

This study presents an experimental investigation of the impact of a supercooled drop onto hydrophilic and superhydrophobic substrates. The aim is to better understand the process of airframe icing caused by supercooled large droplets, which has been recently identified as a severe hazard in aviation. The Weber number and Reynolds number of the impinging drop ranged from 200 to 300 and from 2600 to 5800, respectively. Drop impact, spreading, and rebound were observed using a high-speed video system. The maximum spreading diameter of an impacting drop on hydrophilic surfaces was measured. The temperature effect on this parameter was only minor for a wide range of the drop and substrate temperatures. However, ice/water mixtures emerged when both the drop and substrate temperatures were below 0 °C. Similarly, drop rebound on superhydrophobic substrates was significantly hindered by solidification when supercooled drop impacted onto substrates below the freezing point. The minimum receding diameter and the speed of ice accretion on the substrate were measured for various wall temperatures. Both parameters increased almost linearly with decreasing wall temperature, but eventually leveled off beyond a certain substrate temperature. The rate of ice formation on the substrate was significantly higher than the growth rate of free ice dendrites, implying that multiple nucleation sites were present.

Correction to “Changes in the Earth's rotation by tectonic movements”

NASA Astrophysics Data System (ADS)

Vermeersen, L. L. A.; Vlaar, N. J.

1993-06-01

Present-day true polar wander and the secular non-tidal acceleration of the earth are usually attributed to post-glacial rebound. In the models which relate this rebound to changes in rotation, the mantle is assumed to relax passively to the melted ice-loads. The lithosphere is usually modeled as a highly viscous upper layer in these models, having viscosities which exceed mantle viscosities by several orders of magnitude. We propose that lithospheric processes unrelated to post-glacial rebound and taking place under non-isostatic conditions are also able to induce non-negligible influences on the earth's rotation. Examples of such processes are mountain building and erosion, foundering flexure of oceanic basins and lithospheric snapbacking resulting from detachment of subducting slabs. Lithospheric and crustal rheologies and intraplate-stresses are the dominant factors in these mechanisms, contrary to the mantle rheologies which are assumed to dominate the process of post-glacial rebound.

Promote Number Sense

ERIC Educational Resources Information Center

Gurganus, Susan

2004-01-01

"Number sense" is "an intuition about numbers that is drawn from all varied meanings of number" (NCTM, 1989, p. 39). Students with number sense understand that numbers are representative of objects, magnitudes, relationships, and other attributes; that numbers can be operated on, compared, and used for communication. It is fundamental knowledge…

Rational-number comparison across notation: Fractions, decimals, and whole numbers.

PubMed

Hurst, Michelle; Cordes, Sara

2016-02-01

Although fractions, decimals, and whole numbers can be used to represent the same rational-number values, it is unclear whether adults conceive of these rational-number magnitudes as lying along the same ordered mental continuum. In the current study, we investigated whether adults' processing of rational-number magnitudes in fraction, decimal, and whole-number notation show systematic ratio-dependent responding characteristic of an integrated mental continuum. Both reaction time (RT) and eye-tracking data from a number-magnitude comparison task revealed ratio-dependent performance when adults compared the relative magnitudes of rational numbers, both within the same notation (e.g., fractions vs. fractions) and across different notations (e.g., fractions vs. decimals), pointing to an integrated mental continuum for rational numbers across notation types. In addition, eye-tracking analyses provided evidence of an implicit whole-number bias when we compared values in fraction notation, and individual differences in this whole-number bias were related to the individual's performance on a fraction arithmetic task. Implications of our results for both cognitive development research and math education are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Vibration characteristics of teak wood filled steel tubes

NASA Astrophysics Data System (ADS)

Danawade, Bharatesh Adappa; Malagi, Ravindra Rachappa

2018-05-01

The objective of this paper is to determine fundamental frequency and damping ratio of teak wood filled steel tubes. Mechanically bonded teak wood filled steel tubes have been evaluated by experimental impact hammer test using modal analysis. The results of impact hammer test were verified and validated by finite element tool ANSYS using harmonic analysis. The error between the two methods was observed to be within acceptable limit.

Number games, magnitude representation, and basic number skills in preschoolers.

PubMed

Whyte, Jemma Catherine; Bull, Rebecca

2008-03-01

The effect of 3 intervention board games (linear number, linear color, and nonlinear number) on young children's (mean age = 3.8 years) counting abilities, number naming, magnitude comprehension, accuracy in number-to-position estimation tasks, and best-fit numerical magnitude representations was examined. Pre- and posttest performance was compared following four 25-min intervention sessions. The linear number board game significantly improved children's performance in all posttest measures and facilitated a shift from a logarithmic to a linear representation of numerical magnitude, emphasizing the importance of spatial cues in estimation. Exposure to the number card games involving nonsymbolic magnitude judgments and association of symbolic and nonsymbolic quantities, but without any linear spatial cues, improved some aspects of children's basic number skills but not numerical estimation precision.

Numbers Defy the Law of Large Numbers

ERIC Educational Resources Information Center

Falk, Ruma; Lann, Avital Lavie

2015-01-01

As the number of independent tosses of a fair coin grows, the rates of heads and tails tend to equality. This is misinterpreted by many students as being true also for the absolute numbers of the two outcomes, which, conversely, depart unboundedly from each other in the process. Eradicating that misconception, as by coin-tossing experiments,…

Percussive tool use by Taï Western chimpanzees and Fazenda Boa Vista bearded capuchin monkeys: a comparison

PubMed Central

Visalberghi, Elisabetta; Sirianni, Giulia; Fragaszy, Dorothy; Boesch, Christophe

2015-01-01

Percussive tool use holds special interest for scientists concerned with human origins. We summarize the findings from two field sites, Taï and Fazenda Boa Vista, where percussive tool use by chimpanzees and bearded capuchins, respectively, has been extensively investigated. We describe the ecological settings in which nut-cracking occurs and focus on four aspects of nut-cracking that have important cognitive implications, namely selection of tools, tool transport, tool modification and modulation of actions to reach the goal of cracking the nut. We comment on similarities and differences in behaviour and consider whether the observed differences reflect ecological, morphological, social and/or cognitive factors. Both species are sensitive to physical properties of tools, adjust their selection of hammers conditionally to the resistance of the nuts and to transport distance, and modulate the energy of their strikes under some conditions. However, chimpanzees transport hammers more frequently and for longer distances, take into account a higher number of combinations of variables and occasionally intentionally modify tools. A parsimonious interpretation of our findings is that morphological, ecological and social factors account for the observed differences. Confirmation of plausible cognitive differences in nut-cracking requires data not yet available. PMID:26483529

Number Games, Magnitude Representation, and Basic Number Skills in Preschoolers

ERIC Educational Resources Information Center

Whyte, Jemma Catherine; Bull, Rebecca

2008-01-01

The effect of 3 intervention board games (linear number, linear color, and nonlinear number) on young children's (mean age = 3.8 years) counting abilities, number naming, magnitude comprehension, accuracy in number-to-position estimation tasks, and best-fit numerical magnitude representations was examined. Pre- and posttest performance was…

Hupa Numbers.

ERIC Educational Resources Information Center

Bennett, Ruth, Ed.; And Others

An introduction to the Hupa number system is provided in this workbook, one in a series of numerous materials developed to promote the use of the Hupa language. The book is written in English with Hupa terms used only for the names of numbers. The opening pages present the numbers from 1-10, giving the numeral, the Hupa word, the English word, and…

Number Sense in the Transition from Natural to Rational Numbers

ERIC Educational Resources Information Center

Van Hoof, Jo; Verschaffel, Lieven; Van Dooren, Wim

2017-01-01

Background: Rational numbers are of critical importance both in mathematics and in other fields of science. However, they form a stumbling block for learners. One widely known source of the difficulty learners have with rational numbers is the natural number bias, that is the tendency to (inappropriately) apply natural number properties in…

Hammer toe repair - discharge

MedlinePlus

... first to achieve this important distinction for online health information and services. Learn more about A.D.A. ... Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein should not be used during any ...

emcee: The MCMC Hammer

NASA Astrophysics Data System (ADS)

Foreman-Mackey, Daniel; Hogg, David W.; Lang, Dustin; Goodman, Jonathan

2013-03-01

We introduce a stable, well tested Python implementation of the affine-invariant ensemble sampler for Markov chain Monte Carlo (MCMC) proposed by Goodman & Weare (2010). The code is open source and has already been used in several published projects in the astrophysics literature. The algorithm behind emcee has several advantages over traditional MCMC sampling methods and it has excellent performance as measured by the autocorrelation time (or function calls per independent sample). One major advantage of the algorithm is that it requires hand-tuning of only 1 or 2 parameters compared to ˜N2 for a traditional algorithm in an N-dimensional parameter space. In this document, we describe the algorithm and the details of our implementation. Exploiting the parallelism of the ensemble method, emcee permits any user to take advantage of multiple CPU cores without extra effort. The code is available online at http://dan.iel.fm/emcee under the GNU General Public License v2.

The NCAA's New Hammer

ERIC Educational Resources Information Center

Wolverton, Brad

2012-01-01

A series of unprecedented scandals has eroded confidence in big-time sports, increasing the appetite for change. Some critics have a tough time seeing the NCAA as a savior; they say the real problem is the NCAA structure itself, which allows athletes to generate billions of dollars for colleges while earning no compensation themselves. Mark A.…

Foot ulcer risk and location in relation to prospective clinical assessment of foot shape and mobility among persons with diabetes.

PubMed

Cowley, Matthew S; Boyko, Edward J; Shofer, Jane B; Ahroni, Jessie H; Ledoux, William R

2008-11-01

We assessed baseline clinical foot shape for 2939 feet of diabetic subjects who were monitored prospectively for foot ulceration. Assessments included hammer/claw toes, hallux valgus, hallux limitus, prominent metatarsal heads, bony prominences, Charcot deformity, plantar callus, foot type, muscle atrophy, ankle and hallux mobility, and neuropathy. Risk factors were linked to ulcer occurrence and location via a Cox proportional hazards model. Hammer/claw toes (hazard ratio [HR] (95% confidence interval [CI])=1.43 (1.06, 1.94) p=0.02), marked hammer/claw toes (HR=1.77 (1.18, 2.66) p=0.006), bony prominences (HR=1.38 (1.02, 1.88), p=0.04), and foot type (Charcot or drop foot vs. neutrally aligned) (HR=2.34 (1.33, 4.10), p=0.003) were significant risk factors for ulceration adjusting for age, body mass index, insulin medication, ulcer history and amputation history. With adjustment for neuropathy only hammer/claw toes (HR=1.40 (1.03, 1.90), p=0.03) and foot type (HR=1.76 (1.04, 3.04), p=0.05) were significantly related to ulceration. However, there was no relationship between ulcer location and foot deformity. Certain foot deformities were predictive of ulceration, although there was no relationship between clinical foot deformity and ulcer location.