Interaction analysis of back-to-back mechanically stabilized earth walls

Directory of Open Access Journals (Sweden)

Sadok Benmebarek

2016-10-01

Full Text Available Back-to-back mechanically stabilized earth walls (BBMSEWs are encountered in bridge approaches, ramp ways, rockfall protection systems, earth dams, levees and noise barriers. However, available design guidelines for BBMSEWs are limited and not applicable to numerical modeling when back-to-back walls interact with each other. The objective of this paper is to investigate, using PLAXIS code, the effects of the reduction in the distance between BBMSEW, the reinforcement length, the quality of backfill material and the connection of reinforcements in the middle, when the back-to-back walls are close. The results indicate that each of the BBMSEWs behaves independently if the width of the embankment between mechanically stabilized earth walls is greater than that of the active zone. This is in good agreement with the result of FHWA design guideline. However, the results show that the FHWA design guideline underestimates the lateral earth pressure when back-to-back walls interact with each other. Moreover, for closer BBMSEWs, FHWA design guideline strongly overestimates the maximum tensile force in the reinforcement. The investigation of the quality of backfill material shows that the minor increase in embankment cohesion can lead to significant reductions in both the lateral earth pressure and the maximum tensile force in geosynthetic. When the distance between the two earth walls is close to zero, the connection of reinforcement between back-to-back walls significantly improves the factor of safety.

Optimization and simulation of tandem column supercritical fluid chromatography separations using column back pressure as a unique parameter.

Science.gov (United States)

Wang, Chunlei; Tymiak, Adrienne A; Zhang, Yingru

2014-04-15

Tandem column supercritical fluid chromatography (SFC) has demonstrated to be a useful technique to resolve complex mixtures by serially coupling two columns of different selectivity. The overall selectivity of a tandem column separation is the retention time weighted average of selectivity from each coupled column. Currently, the method development merely relies on extensive screenings and is often a hit-or-miss process. No attention is paid to independently adjust retention and selectivity contributions from individual columns. In this study, we show how tandem column SFC selectivity can be optimized by changing relative dimensions (length or inner diameter) of the coupled columns. Moreover, we apply column back pressure as a unique parameter for SFC optimization. Continuous tuning of tandem column SFC selectivity is illustrated through column back pressure adjustments of the upstream column, for the first time. In addition, we show how and why changing coupling order of the columns can produce dramatically different separations. Using the empirical mathematical equation derived in our previous study, we also demonstrate a simulation of tandem column separations based on a single retention time measurement on each column. The simulation compares well with experimental results and correctly predicts column order and back pressure effects on the separations. Finally, considerations on instrument and column hardware requirements are discussed.

MEMS pressure sensor with maximum performances by using novel back-side direct-exposure concept featuring through glass vias

Science.gov (United States)

Mukhopadhyay, B.; Fritz, M.; Mackowiak, P.; Vu, T. C.; Ehrmann, O.; Lang, K.-D.; Ngo, H.-D.

2013-05-01

Design, simulation, fabrication, and characterization of novel MEMS pressure sensors with new back-side-direct-exposure packaging concept are presented. The sensor design is optimized for harsh environments e.g. space, military, offshore and medical applications. Unbreakable connection between the active side of the Si-sensor and the protecting glass capping was realized by anodic bonding using a thin layer of metal. To avoid signal corruption of the measured pressure caused by an encapsulation system, the media has direct contact to the backside of the Si membrane and can deflect it.

Reactor shutdown back-up system

International Nuclear Information System (INIS)

Hirao, Seizo; Sakashita, Motoaki.

1982-01-01

Purpose: To prevent back flow of poison upon injection to a moderator recycling pipeway. Constitution: In a nuclear reactor comprising a moderator recycling system for recycling and cooling moderator through a control rod guide pipe and a rapid poison injection system for rapidly injecting a poison solution at high density into the moderator by way of the same control rod guide pipe as a reactor shutdown back-up system, a mechanism is provided for preventing the back flow of a poison solution at high density into the moderator recycling system upon rapid injection of poison. An orifice provided in the joining pipeway to the control rod guide pipe on the side of the moderator recycling system is utilized as the back flow preventing device for the poison solution and the diameter for the orifice is determined so as to provide a constant ratio between the pressure loss in the control rod guide pipe and the pressure loss in the moderator recycling system pipe line upon usual reactor operation. (Kawakami, Y.)

Activation of lower back muscles via FES for pressure sores prevention in paraplegia: a case study.

Science.gov (United States)

Vanoncini, M; Holderbaum, W; Andrews, B J

2010-04-01

The aim of this paper is to show the feasibility of the use of functional electrical stimulation (FES) applied to the lower back muscles for pressure sores prevention in paraplegia. The hypothesis under study is that FES induces a change in the pressure distribution on the contact area during sitting. Tests were conducted on a paraplegic subject (T5), sitting on a standard wheelchair and cushion. Trunk extensors (mainly the erector spinae) were stimulated using surface electrodes placed on the skin. A pressure mapping system was used to measure the pressure on the sitting surface in four situations: (a) no stimulation; (b) stimulation on one side of the spine only; (c) stimulation on both sides, at different levels; and (d) stimulation at the same level on both sides, during pressure-relief manoeuvres. A session of prolonged stimulation was also conducted. The experimental results show that the stimulation of the erector spinae on one side of the spine can induce a trunk rotation on the sagittal plane, which causes a change in the pressure distribution. A decrease of pressure on the side opposite to the stimulation was recorded. The phenomenon is intensified when different levels of stimulation are applied to the two sides, and such change can be sustained for a considerable time (around 5 minutes). The stimulation did not induce changes during pressure-relief manoeuvres. Finally, from this research we can conclude that the stimulation of the trunk extensors can be a useful tool for pressure sores prevention, and can potentially be used in a routine for pressure sores prevention based on periodical weight shifts.

Cortical sensorimotor processing of painful pressure in patients with chronic lower back pain – An optical neuroimaging study using fNIRS

Directory of Open Access Journals (Sweden)

Andrea Vrana

2016-11-01

Full Text Available In this study we investigated sensorimotor processing of painful pressure stimulation on the lower back of patients with chronic lower back pain (CLBP by using functional near-infrared spectroscopy (fNIRS to measure changes in cerebral hemodynamics and oxygenation. The main objectives were whether patients with CLBP show different relative changes in oxy- and deoxyhemoglobin (O2Hb and HHb in the supplementary motor area (SMA and primary somatosensory cortex (S1 compared to healthy controls (HC. Twelve patients with CLBP (32 ± 6.1 years; range: 24 – 44 years; 9 women and twenty HCs (33.5 ± 10.7 years; range 22-61 years; 8 women participated in the study. Painful and non-painful pressure stimulation was exerted with a thumb grip perpendicularly to the spinous process of the lumbar spine. A force sensor was attached at the spinous process in order control for pressure forces. Tactile stimulation was realized by a one-finger brushing. Hemodynamic changes in the SMA and S1 were measured bilaterally using a multi-channel continuous wave fNIRS imaging system and a multi-distant probe array. Patients with CLBP showed significant stimulus-evoked hemodynamic responses in O2Hb only in the right S1, while the healthy controls exhibited significant O2Hb changes bilaterally in both, SMA and S1. However, the group comparisons revealed no significant different hemodynamic responses in O2Hb and HHb in the SMA and S1 after both pressure stimulations. This non-significant result might be driven by the high inter-subject variability of hemodynamic responses that has been observed within the patients group. In conclusion, we could not find different stimulus-evoked hemodynamic responses in patients with CLBP compared to HCs. This indicates that neither S1 nor the SMA show a specificity for CLBP during pressure stimulation on the lower back. However, the results point to a potential subgrouping regarding task-related cortical activity within the CLBP group; a

Pressure ulcers: Back to the basics.

Science.gov (United States)

Agrawal, Karoon; Chauhan, Neha

2012-05-01

Pressure ulcer in an otherwise sick patient is a matter of concern for the care givers as well as the medical personnel. A lot has been done to understand the disease process. So much so that USA and European countries have established advisory panels in their respective continents. Since the establishment of these organizations, the understanding of the pressure ulcer has improved significantly. The authors feel that the well documented and well publicized definition of pressure ulcer is somewhat lacking in the correct description of the disease process. Hence, a modified definition has been presented. This disease is here to stay. In the process of managing these ulcers the basic pathology needs to be understood well. Pressure ischemia is the main reason behind the occurrence of ulceration. Different extrinsic and intrinsic factors have been described in detail with review of literature. There are a large number of risk factors causing ulceration. The risk assessment scales have eluded the surgical literature and mostly remained in nursing books and websites. These scales have been reproduced for completion of the basics on decubitus ulcer. The classification of the pressure sores has been given in a comparative form to elucidate that most of the classifications are the same except for minor variations. The management of these ulcers is ever evolving but the age old saying of "prevention is better than cure" suits this condition the most.

Pressure ulcers: Back to the basics

Directory of Open Access Journals (Sweden)

Karoon Agrawal

2012-01-01

Full Text Available Pressure ulcer in an otherwise sick patient is a matter of concern for the care givers as well as the medical personnel. A lot has been done to understand the disease process. So much so that USA and European countries have established advisory panels in their respective continents. Since the establishment of these organizations, the understanding of the pressure ulcer has improved significantly. The authors feel that the well documented and well publicized definition of pressure ulcer is somewhat lacking in the correct description of the disease process. Hence, a modified definition has been presented. This disease is here to stay. In the process of managing these ulcers the basic pathology needs to be understood well. Pressure ischemia is the main reason behind the occurrence of ulceration. Different extrinsic and intrinsic factors have been described in detail with review of literature. There are a large number of risk factors causing ulceration. The risk assessment scales have eluded the surgical literature and mostly remained in nursing books and websites. These scales have been reproduced for completion of the basics on decubitus ulcer. The classification of the pressure sores has been given in a comparative form to elucidate that most of the classifications are the same except for minor variations. The management of these ulcers is ever evolving but the age old saying of "prevention is better than cure" suits this condition the most.

Pressure ulcers: Back to the basics

Science.gov (United States)

Agrawal, Karoon; Chauhan, Neha

2012-01-01

Pressure ulcer in an otherwise sick patient is a matter of concern for the care givers as well as the medical personnel. A lot has been done to understand the disease process. So much so that USA and European countries have established advisory panels in their respective continents. Since the establishment of these organizations, the understanding of the pressure ulcer has improved significantly. The authors feel that the well documented and well publicized definition of pressure ulcer is somewhat lacking in the correct description of the disease process. Hence, a modified definition has been presented. This disease is here to stay. In the process of managing these ulcers the basic pathology needs to be understood well. Pressure ischemia is the main reason behind the occurrence of ulceration. Different extrinsic and intrinsic factors have been described in detail with review of literature. There are a large number of risk factors causing ulceration. The risk assessment scales have eluded the surgical literature and mostly remained in nursing books and websites. These scales have been reproduced for completion of the basics on decubitus ulcer. The classification of the pressure sores has been given in a comparative form to elucidate that most of the classifications are the same except for minor variations. The management of these ulcers is ever evolving but the age old saying of “prevention is better than cure” suits this condition the most. PMID:23162223

On the enhancement of the back-to-back two-electron-one photon ionization in molecules

Science.gov (United States)

Amusia, Miron; Drukarev, Eugene

2014-05-01

Recently, the long ago predicted quasi-free mechanism of two-electron photoionization was detected already at relatively low energy photoionization in He. It was observed that some pairs of electrons are leaving the target atom back-to-back, i.e. in opposite direction with almost the same energy. They have opposite spin directions. The cross-section of this process depends upon the probability for a pair of electrons to be close to each other before meeting the incoming photon. Such probability is greatly enhanced in molecules with covalent bonding, like H2. In this and similar molecules the electrons spend an essential part of time being between nuclei and thus screening them from each other. We demonstrate that indeed the back-to-back contribution is much bigger in H2 than in He. We analyze qualitatively some other situations that lead to relative growth of back-to-back contribution. Atoms with electrons with bigger principal quantum numbers have bigger back-to-back contributions. An external pressure applied to molecules forces electrons to be closer to each other. As a result for them the back-to-back contribution can be controllable enhanced.

Low pressure pain thresholds are associated with, but does not predispose for, low back pain

DEFF Research Database (Denmark)

O'Neill, Søren; Kjær, Per; Graven-Nielsen, Thomas

2011-01-01

Chronic pain is often associated with hyperalgesia in cross-sectional studies. In the present study, a random cohort of 40-year-old individuals (n = 264) from the general population was assessed for low back pain (LBP) status and pressure pain threshold (PPT), with follow-up assessment 4 and 8......-lasting LBP, those with a low PPT at baseline (lower 10% percentile) had no increased risk of developing LBP (p > 0.05). The findings indicate that PPT decreases as a consequence of long-lasting pain, whereas a low PPT seems not to constitute a separate risk factor for the development of LBP....

Testing Predictions of a Landscape Evolution Model Using the Dragon’s Back Pressure Ridge as a Natural Experiment

Science.gov (United States)

Perignon, M. C.; Tucker, G. E.; Hilley, G. E.; Arrowsmith, R.

2009-12-01

Landscape evolution models use mass transport rules to simulate the temporal development of topography over timescales too long for humans to observe. As such, these models are difficult to test using the decadal time-scale observations of topographic change that can be directly measured. In contrast, natural systems in which driving forces, boundary conditions, and timing of landscape evolution over millennial time-scales can be well constrained may be used to test the ability of mathematical models to reproduce various attributes of the observed topography. The Dragon’s Back pressure ridge, a 4km x 0.5 km x 100 m high area of elevated topography elongate parallel to the south-central San Andreas fault (SAF) in California, serves as a natural laboratory for studying how the timing and spatial distribution of uplift affects patterns of erosion and topography. Geologic mapping and geophysical studies show that, at this location, the Pacific plate is forced over a relatively stationary shallow discontinuity in the SAF, resulting in local uplift. Continued right-lateral motion along the fault results in the movement of material though the uplift zone at the SAF slip rate of 35 mm/yr. This allows for the substitution of space for time when observing topographic change, and can be used to constrain the tectonic conditions to which the surface processes responded and developed the resulting landscape. We used the CHILD model of landscape evolution to recreate the Dragon’s Back pressure ridge system in order to test the reliability of the model predictions and determine the necessary and sufficient conditions to explain the observed topography. To do this, we first ran a Monte Carlo simulation in which we varied the model inputs within a range of plausible values. We then compared the model results with LiDAR topography from the Dragon’s Back pressure ridge to determine which combinations of input parameters best reproduced the observed topography and how well it

Investigation of the Condensation Effect at IRWST Pool Surface on Containment Back Pressure in APR1400 Containment

International Nuclear Information System (INIS)

Lee, Eui Jong; Lee, Jin Yong; Lee, Byung Chul

2006-01-01

The APR1400 has several new design concepts in order to improve the plant safety functions during a postulated accident. The In-Containment Refueling Water Storage Tank (IRWST) is one of the new design concepts of APR1400 and installed at the bottom of containment building to promote the plant safety functions by simplifying emergency core cooling water source and preventing release of the fission product during an accidents. This design feature, however, brings about uncertainty factors which may necessitate conventional prediction of temperature and pressure of containment building improved or revised under accident conditions. The hot steam which is released from RCS break enters into the IRWST through four Pressure Relief Dampers (PRDs). It is expected to be condensed with water stored in IRWST, colder than incoming steam. The purpose of this study is to examine closely the influence of the condensation effect at IRWST on containment back pressure in APR1400 containment building using the GOTHIC code which can predict the steam condensation on IRWST pool surface

Back to Work

Science.gov (United States)

Fernandez, Kim

2010-01-01

The economic downturn hit working America particularly hard, as agricultural, automotive, manufacturing, and retail jobs in many corners of the country all but evaporated. Consumers continue to cut back, and jobless rates in many states have eclipsed levels not seen in decades. Out of work and under pressure, many Americans are turning to the…

How to care for pressure sores

Science.gov (United States)

... ency/patientinstructions/000740.htm How to care for pressure sores To use the sharing features on this page, ... Shoulders Back Back of head Caring for a Pressure Sore Stage I or II sores will heal if ...

Reactive extraction of carboxylic acids from apolar hydrocarbons using aqueous solutions of sodium hydrogen carbonate with back-recovery using carbon dioxide under pressure

NARCIS (Netherlands)

Kuzmanovic, B.; Kuipers, N.J.M.; de Haan, A.B.; Kwant, Gerard

2005-01-01

A combination of using an aqueous solution of sodium hydrogen carbonate for forward-extraction of carboxylic acids from a dilute apolar organic solvent, and carbon dioxide under pressure for its back-recovery, is studied. Used in combination, these two steps might provide a technique for the

Is One Trial Sufficient to Obtain Excellent Pressure Pain Threshold Reliability in the Low Back of Asymptomatic Individuals? A Test-Retest Study.

Science.gov (United States)

Balaguier, Romain; Madeleine, Pascal; Vuillerme, Nicolas

2016-01-01

The assessment of pressure pain threshold (PPT) provides a quantitative value related to the mechanical sensitivity to pain of deep structures. Although excellent reliability of PPT has been reported in numerous anatomical locations, its absolute and relative reliability in the lower back region remains to be determined. Because of the high prevalence of low back pain in the general population and because low back pain is one of the leading causes of disability in industrialized countries, assessing pressure pain thresholds over the low back is particularly of interest. The purpose of this study study was (1) to evaluate the intra- and inter- absolute and relative reliability of PPT within 14 locations covering the low back region of asymptomatic individuals and (2) to determine the number of trial required to ensure reliable PPT measurements. Fifteen asymptomatic subjects were included in this study. PPTs were assessed among 14 anatomical locations in the low back region over two sessions separated by one hour interval. For the two sessions, three PPT assessments were performed on each location. Reliability was assessed computing intraclass correlation coefficients (ICC), standard error of measurement (SEM) and minimum detectable change (MDC) for all possible combinations between trials and sessions. Bland-Altman plots were also generated to assess potential bias in the dataset. Relative reliability for both intra- and inter- session was almost perfect with ICC ranged from 0.85 to 0.99. With respect to the intra-session, no statistical difference was reported for ICCs and SEM regardless of the conducted comparisons between trials. Conversely, for inter-session, ICCs and SEM values were significantly larger when two consecutive PPT measurements were used for data analysis. No significant difference was observed for the comparison between two consecutive measurements and three measurements. Excellent relative and absolute reliabilities were reported for both intra

The nuclear regulatory challenge of judging safety back fits

International Nuclear Information System (INIS)

2002-01-01

The economic pressures of electricity market competition have led nuclear power plant operators to seek ways to increase electricity production and to reduce operating costs at their plants. Corresponding pressures on the regulatory bodies include operator demand to reduce regulatory burdens perceived as unnecessary and general resistance to consider safety back-fits sought by the regulator. The purpose of this report is to describe potential situations giving rise to safety back-fit questions and to discuss regulatory approaches for judging the back-fits. The intended audience for this report is primarily nuclear regulators, although the information and ideas may also be of interest to nuclear operating organisations, other industry organisations and the general public. (author)

ICECON: a computer program used to calculate containment back pressure for LOCA analysis (including ice condenser plants)

International Nuclear Information System (INIS)

1976-07-01

The ICECON computer code provides a method for conservatively calculating the long term back pressure transient in the containment resulting from a hypothetical Loss-of-Coolant Accident (LOCA) for PWR plants including ice condenser containment systems. The ICECON computer code was developed from the CONTEMPT/LT-022 code. A brief discussion of the salient features of a typical ice condenser containment is presented. Details of the ice condenser models are explained. The corrections and improvements made to CONTEMPT/LT-022 are included. The organization of the code, including the calculational procedure, is outlined. The user's manual, to be used in conjunction with the CONTEMPT/LT-022 user's manual, a sample problem, a time-step study (solution convergence) and a comparison of ICECON results with the results of the NSSS vendor are presented. In general, containment pressure calculated with the ICECON code agree with those calculated by the NSSS vendor using the same mass and energy release rates to the containment

Pulsar formation and the fall back mass fraction

International Nuclear Information System (INIS)

Colgate, S.A.

1988-01-01

The picture of the explosion of 1987A following collapse to a neutron star and neutrino emission is difficult to reconcile with the subsequent behavior of the ejected mass. It is shown that the inner solar mass of ejected matter should progressively fall back onto the neutron star after it collides with the outer 10--15 M circle and after an initial phase of explosion driven by a hot bubble for t approx-gt 2 x 10 3 s. This fall back is augmented due to heating by the radioactive decay of 56 Ni. The matter accreted onto the neutron star rapidly cools due to neutrino emission and merges with the neutron star, thus resulting in zero back pressure to the free falling matter. The predicted fall back mass approx-gt 1 M circle is far larger than is consistent with observations. The author discusses how the most likely explanation is that the hot radiation dominated bubble is continuously heated by neutrino emission from continuing accretion. This accretion continues until the presumed pulsar magnetic field exceeds the bubble pressure

Low back pain and postural control, effects of task difficulty on centre of pressure and spinal kinematics.

Science.gov (United States)

Schelldorfer, Sarah; Ernst, Markus Josef; Rast, Fabian Marcel; Bauer, Christoph Michael; Meichtry, André; Kool, Jan

2015-01-01

Association of low back pain and standing postural control (PC) deficits are reported inconsistently. Demands on PC adaptation strategies are increased by restraining the input of visual or somatosensory senses. The objectives of the current study are, to investigate whether PC adaptations of the spine, hip and the centre of pressure (COP) differ between patients reporting non-specific low back pain (NSLBP) and asymptomatic controls. The PC adaption strategies of the thoracic and lumbar spine, the hip and the COP were measured in fifty-seven NSLBP patients and 22 asymptomatic controls. We tested three "feet together" conditions with increasing demands on PC strategies, using inertial measurement units (IMUs) on the spine and a Wii balance board for centre of pressure (COP) parameters. The differences between NSLBP patients and controls were most apparent when the participants were blindfolded, but remaining on a firm surface. While NSLBP patients had larger thoracic and lumbar spine mean absolute deviations of position (MADpos) in the frontal plane, the same parameters decreased in control subjects (relative change (RC): 0.23, 95% confidence interval: 0.03 to 0.45 and 0.03 to 0.48). The Mean absolute deviation of velocity (MADvel) of the thoracic spine in the frontal plane showed a similar and significant effect (RC: 0.12 95% CI: 0.01 to 0.25). Gender, age and pain during the measurements affected some parameters significantly. PC adaptions differ between NSLBP patients and asymptomatic controls. The differences are most apparent for the thoracic and lumbar parameters of MADpos, in the frontal plane and while the visual condition was removed. Copyright © 2014 Elsevier B.V. All rights reserved.

Disrupted Self-Perception in People With Chronic Low Back Pain. Further Evaluation of the Fremantle Back Awareness Questionnaire.

Science.gov (United States)

Wand, Benedict Martin; Catley, Mark Jon; Rabey, Martin Ian; O'Sullivan, Peter Bruce; O'Connell, Neil Edward; Smith, Anne Julia

2016-09-01

Several lines of evidence suggest that body perception is altered in people with chronic back pain. Maladaptive perceptual awareness of the back might contribute to the pain experience as well as serve as a target for treatment. The Fremantle Back Awareness Questionnaire (FreBAQ) is a simple questionnaire recently developed to assess back-specific altered self-perception. The aims of this study were to present the outcomes of a comprehensive evaluation of the questionnaire's psychometric properties and explore the potential relationships between body perception, nociceptive sensitivity, distress, and beliefs about back pain and the contribution these factors might play in explaining pain and disability. Two hundred fifty-one people with chronic back pain completed the questionnaire as well as a battery of clinical tests. The Rasch model was used to explore the questionnaires' psychometric properties and correlation and multiple linear regression analyses were used to explore the relationship between altered body perception and clinical status. The FreBAQ appears unidimensional with no redundant items, has minimal ceiling and floor effects, acceptable internal consistency, was functional on the category rating scale, and was not biased by demographic or clinical variables. FreBAQ scores were correlated with sensitivity, distress, and beliefs and were uniquely associated with pain and disability. Several lines of evidence suggest that body perception might be disturbed in people with chronic low back pain, possibly contributing to the condition and offering a potential target for treatment. The FreBAQ was developed as a quick and simple way of measuring back-specific body perception in people with chronic low back pain. The questionnaire appears to be a psychometrically sound way of assessing altered self-perception. The level of altered self-perception is positively correlated with pain intensity and disability as well as showing associations with psychological

Modeling the Deterioration of Engine and Low Pressure Compressor Performance During a Roll Back Event Due to Ice Accretion

Science.gov (United States)

Veres, Joseph P.; Jorgenson, Philip, C. E.; Jones, Scott M.

2014-01-01

The main focus of this study is to apply a computational tool for the flow analysis of the engine that has been tested with ice crystal ingestion in the Propulsion Systems Laboratory (PSL) of NASA Glenn Research Center. A data point was selected for analysis during which the engine experienced a full roll back event due to the ice accretion on the blades and flow path of the low pressure compressor. The computational tool consists of the Numerical Propulsion System Simulation (NPSS) engine system thermodynamic cycle code, and an Euler-based compressor flow analysis code, that has an ice particle melt estimation code with the capability of determining the rate of sublimation, melting, and evaporation through the compressor blade rows. Decreasing the performance characteristics of the low pressure compressor (LPC) within the NPSS cycle analysis resulted in matching the overall engine performance parameters measured during testing at data points in short time intervals through the progression of the roll back event. Detailed analysis of the fan-core and LPC with the compressor flow analysis code simulated the effects of ice accretion by increasing the aerodynamic blockage and pressure losses through the low pressure compressor until achieving a match with the NPSS cycle analysis results, at each scan. With the additional blockages and losses in the LPC, the compressor flow analysis code results were able to numerically reproduce the performance that was determined by the NPSS cycle analysis, which was in agreement with the PSL engine test data. The compressor flow analysis indicated that the blockage due to ice accretion in the LPC exit guide vane stators caused the exit guide vane (EGV) to be nearly choked, significantly reducing the air flow rate into the core. This caused the LPC to eventually be in stall due to increasing levels of diffusion in the rotors and high incidence angles in the inlet guide vane (IGV) and EGV stators. The flow analysis indicating

Glovebox pressure relief and check valve

Energy Technology Data Exchange (ETDEWEB)

Blaedel, K.L.

1986-03-17

This device is a combined pressure relief valve and check valve providing overpressure protection and preventing back flow into an inert atmosphere enclosure. The pressure relief is embodied by a submerged vent line in a mercury reservior, the releif pressure being a function of the submerged depth. The pressure relief can be vented into an exhaust system and the relieving pressure is only slightly influenced by the varying pressure in the exhaust system. The check valve is embodied by a ball which floats on the mercury column and contacts a seat whenever vacuum exists within the glovebox enclosure. Alternatively, the check valve is embodied by a vertical column of mercury, the maximum back pressure being a function of the height of the column of mercury.

Glovebox pressure relief and check valve

International Nuclear Information System (INIS)

Blaedel, K.L.

1986-01-01

This device is a combined pressure relief valve and check valve providing overpressure protection and preventing back flow into an inert atmosphere enclosure. The pressure relief is embodied by a submerged vent line in a mercury reservior, the releif pressure being a function of the submerged depth. The pressure relief can be vented into an exhaust system and the relieving pressure is only slightly influenced by the varying pressure in the exhaust system. The check valve is embodied by a ball which floats on the mercury column and contacts a seat whenever vacuum exists within the glovebox enclosure. Alternatively, the check valve is embodied by a vertical column of mercury, the maximum back pressure being a function of the height of the column of mercury

Prevention: The Best Treatment for Back Pain

Science.gov (United States)

... your favorite weekend sports. A tight neck and hamstrings also put unneeded pressure on the back. Make ... and restriction during motion that could signal an injury or impaired function.” DOs use OMT to help ...

Comparison between beryllium and diamond-backing plates in diamond-anvil cells

DEFF Research Database (Denmark)

Periotto, Benedetta; Nestola, Fabrizio; Balic Zunic, Tonci

2011-01-01

A direct comparison between two complete intensity datasets, collected on the same sample loaded in two identical diamond-anvil pressure cells equipped, respectively, with beryllium and diamond backing plates was performed. The results clearly demonstrate that the use of diamond-backing plates...

The importance of ship log data: reconstructing North Atlantic, European and Mediterranean sea level pressure fields back to 1750

Energy Technology Data Exchange (ETDEWEB)

Kuettel, M.; Wanner, H. [University of Bern, Oeschger Centre for Climate Change Research (OCCR), and Institute of Geography, Climatology and Meteorology, Bern (Switzerland); Xoplaki, E. [University of Bern, Oeschger Centre for Climate Change Research (OCCR), and Institute of Geography, Climatology and Meteorology, Bern (Switzerland); EEWRC, The Cyprus Institute, Nicosia (Cyprus); Gallego, D. [Universidad Pablo de Olavide de Sevilla, Departamento de Sistemas Fisicos, Quimicos y Naturales, Sevilla (Spain); Luterbacher, J. [University of Bern, Oeschger Centre for Climate Change Research (OCCR), and Institute of Geography, Climatology and Meteorology, Bern (Switzerland); Justus-Liebig University of Giessen, Department of Geography, Climatology, Climate Dynamics and Climate Change, Giessen (Germany); Garcia-Herrera, R. [Universidad Complutense de Madrid, Departamento de Fisica de la Tierra II, Facultad de CC Fisicas, Madrid (Spain); Allan, R. [Met Office Hadley Centre, Exeter (United Kingdom); Barriendos, M. [University of Barcelona, Department of Modern History, Barcelona (Spain); Jones, P.D. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom); Wheeler, D. [University of Sunderland, Faculty of Applied Sciences, Sunderland (United Kingdom)

2010-06-15

Local to regional climate anomalies are to a large extent determined by the state of the atmospheric circulation. The knowledge of large-scale sea level pressure (SLP) variations in former times is therefore crucial when addressing past climate changes across Europe and the Mediterranean. However, currently available SLP reconstructions lack data from the ocean, particularly in the pre-1850 period. Here we present a new statistically-derived 5 x 5 resolved gridded seasonal SLP dataset covering the eastern North Atlantic, Europe and the Mediterranean area (40 W-50 E; 20 N-70 N) back to 1750 using terrestrial instrumental pressure series and marine wind information from ship logbooks. For the period 1750-1850, the new SLP reconstruction provides a more accurate representation of the strength of the winter westerlies as well as the location and variability of the Azores High than currently available multiproxy pressure field reconstructions. These findings strongly support the potential of ship logbooks as an important source to determine past circulation variations especially for the pre-1850 period. This new dataset can be further used for dynamical studies relating large-scale atmospheric circulation to temperature and precipitation variability over the Mediterranean and Eurasia, for the comparison with outputs from GCMs as well as for detection and attribution studies. (orig.)

Pressure recovery in a diffuser for gas centrifuge

International Nuclear Information System (INIS)

Hanzawa, Masatoshi; Takashima, Yoichi; Mikami, Hisashi

1977-01-01

The pressure recovery of supersonic flow at very low density was studied in a vane-island type diffuser for gas centrifuge. A tester of diffuser with a rapidly rotating cylinder was used in experiments. Wall static pressures were measured at many points in the diffuser to observe the static pressure distribution. The change of pressure distribution with back pressure and the effect of flow rate were investigated. Pressure distribution showed that the pressure recovery occurred in the converging section. The pressure ratio increased linearly with the back pressure in this experimental range and the effect of flow rate was not observed. A numerical analysis of the pressure recovery in the channel section of the diffuser was made by applying the finite difference method to the slender-channel equations. The pressure distribution obtained in experiments could be explained as a result of supersonic compression with reverse flow. (auth.)

Squeezed fermions and back-to-back correlations

International Nuclear Information System (INIS)

Panda, P.K.; Krein, G.; Padula, S.S.; Csoergoe, T.; Hama, Y.

2001-01-01

Back-to-back correlations of asymptotic fermion pairs appear if in-medium interactions lead to mass modifications of fermion states in a thermalized medium. The back-to-back correlations of protons and anti-protons will be experimentally observable in ultrarelativistic heavy ion collisions. The strength of back-to-back correlations of fermions can be unlimitedly large, diverging as the momentum of the pair increases and the net baryon density decreases. (author)

Squeezed fermions and back-to-back correlations

Energy Technology Data Exchange (ETDEWEB)

Panda, P.K.; Krein, G.; Padula, S.S. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Csoergoe, T. [Hungarian Academy of Sciences, Budapest (Hungary). Research Institute for Particle and Nuclear Physics (RMKI, KFKI); Hama, Y. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

2001-07-01

Back-to-back correlations of asymptotic fermion pairs appear if in-medium interactions lead to mass modifications of fermion states in a thermalized medium. The back-to-back correlations of protons and anti-protons will be experimentally observable in ultrarelativistic heavy ion collisions. The strength of back-to-back correlations of fermions can be unlimitedly large, diverging as the momentum of the pair increases and the net baryon density decreases. (author)

Characteristics of molybdenum bilayer back contacts for Cu(In,Ga)Se2 solar cells on Ti foils

International Nuclear Information System (INIS)

Roger, Charles; Noël, Sébastien; Sicardy, Olivier; Faucherand, Pascal; Grenet, Louis; Karst, Nicolas; Fournier, Hélène; Roux, Frédéric; Ducroquet, Frédérique; Brioude, Arnaud; Perraud, Simon

2013-01-01

Molybdenum back contact properties are critical for Cu(In,Ga)Se 2 (CIGS) solar cell performance on metallic substrates. In this work, we investigated the properties of sputter-deposited Mo bilayer back contacts on Ti foils. The morphology, electrical resistivity, optical reflectance and residual mechanical stress of the bottom Mo layer were modified by varying the working pressure during its deposition. Working pressures ranging from 0.27 Pa to 4.00 Pa were used. The top Mo layer was deposited using constant conditions at a pressure of 0.13 Pa. It was demonstrated that unlike a Mo monolayer, the use of a Mo bilayer allows controlling the mechanical stress at the Mo/CIGS interface without degrading the optical reflectance and the electrical resistance of the back contact. It was also found that the morphology of the bottom Mo layer affects the growth of the top Mo layer, resulting in a modified back contact surface morphology. This induces changes in the crystalline orientation of the CIGS layer. The resulting solar cell characteristics strongly vary as a function of the bottom Mo layer deposition pressure. A bottom Mo layer growth at 2.93 Pa allows improving the solar cell conversion efficiency by 1.5 times compared to a bottom Mo layer deposited at 0.27 Pa. Using the improved Mo bilayer back contact, a maximum solar cell efficiency of 10.0% was obtained without sodium addition nor anti-reflection coating. - Highlights: • Mo bilayer back contacts for Cu(In,Ga)Se 2 solar cells were grown on Ti substrates. • The sputtering pressure of the bottom Mo layer was varied between 0.27 Pa and 4 Pa. • The top Mo layer controls the optical and electrical properties of the back contact. • The structure of the bottom Mo layer influences the morphology of the top Mo layer. • The back contact affects the CIGS texture, device series resistance and efficiency

People with chronic low back pain have poorer balance than controls in challenging tasks.

Science.gov (United States)

da Silva, Rubens A; Vieira, Edgar R; Fernandes, Karen B P; Andraus, Rodrigo A; Oliveira, Marcio R; Sturion, Leandro A; Calderon, Mariane G

2018-06-01

To compare the balance of individuals with and without chronic low back pain during five tasks. The participants were 20 volunteers, 10 with and 10 without nonspecific chronic low back pain, mean age 34 years, 50% females. The participants completed the following balance tasks on a force platform in random order: (1) two-legged stance with eyes open, (2) two-legged stance with eyes closed, (3) semi-tandem with eyes open, (4) semi-tandem with eyes closed and (5) one-legged stance with eyes open. The participants completed three 60-s trials of tasks 1-4, and three 30-s trials of task 5 with 30-s rests between trials. The center of pressure area, velocity and frequency in the antero-posterior and medio-lateral directions were computed during each task, and compared between groups and tasks. Participants with chronic low back pain presented significantly larger center of pressure area and higher velocity than the healthy controls (p chronic low back pain group than two-legged stance tasks 1 and 2 (effect size >1.37 vs. effect size chronic low back pain presented poorer postural control using center of pressure measurements than the healthy controls, mainly during more challenging balance tasks such as semi-tandem and one-legged stance conditions. Implications for Rehabilitation People with chronic low back had poorer balance than those without it. Balance tasks need to be sensitive to capture impairments. Balance assessments during semi-tandem and one-legged stance were the most sensitive tasks to determine postural control deficit in people with chronic low back. Balance assessment should be included during rehabilitation programs for individuals with chronic low back pain for better clinical decision making related to balance re-training as necessary.

Reynolds-Averaged Turbulence Model Assessment for a Highly Back-Pressured Isolator Flowfield

Science.gov (United States)

Baurle, Robert A.; Middleton, Troy F.; Wilson, L. G.

2012-01-01

The use of computational fluid dynamics in scramjet engine component development is widespread in the existing literature. Unfortunately, the quantification of model-form uncertainties is rarely addressed with anything other than sensitivity studies, requiring that the computational results be intimately tied to and calibrated against existing test data. This practice must be replaced with a formal uncertainty quantification process for computational fluid dynamics to play an expanded role in the system design, development, and flight certification process. Due to ground test facility limitations, this expanded role is believed to be a requirement by some in the test and evaluation community if scramjet engines are to be given serious consideration as a viable propulsion device. An effort has been initiated at the NASA Langley Research Center to validate several turbulence closure models used for Reynolds-averaged simulations of scramjet isolator flows. The turbulence models considered were the Menter BSL, Menter SST, Wilcox 1998, Wilcox 2006, and the Gatski-Speziale explicit algebraic Reynolds stress models. The simulations were carried out using the VULCAN computational fluid dynamics package developed at the NASA Langley Research Center. A procedure to quantify the numerical errors was developed to account for discretization errors in the validation process. This procedure utilized the grid convergence index defined by Roache as a bounding estimate for the numerical error. The validation data was collected from a mechanically back-pressured constant area (1 2 inch) isolator model with an isolator entrance Mach number of 2.5. As expected, the model-form uncertainty was substantial for the shock-dominated, massively separated flowfield within the isolator as evidenced by a 6 duct height variation in shock train length depending on the turbulence model employed. Generally speaking, the turbulence models that did not include an explicit stress limiter more closely

Metal extrusion using hydrostatic pressures

International Nuclear Information System (INIS)

Sauve, Ch.

1965-01-01

The main problems connected with the deformation of metals due to extrusion are described. A method is put forward for calculating the rational rate of percentage deformation in the case of bar extrusion using a cylindrical container; reference is made to previous work on extrusion using a hydrostatic pressure with or without back-pressure. An extrusion process is described using hydrostatic pressure, without back-pressure, and using the lubricant for transmitting the thrust. This process has been used for eight years by the C.E.A. for the extrusion of a very wide range of metals, from beryllium to uranium and including steels; it leads to excellent surface textures. A very fine crystallization can be obtained on extruded products when the rate of extrusion is very low. There appears to be nothing against the use of high extrusion rates using this method. (author) [fr

Characteristics of molybdenum bilayer back contacts for Cu(In,Ga)Se{sub 2} solar cells on Ti foils

Energy Technology Data Exchange (ETDEWEB)

Roger, Charles, E-mail: charles.rgr@gmail.com [CEA, LITEN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Noël, Sébastien; Sicardy, Olivier; Faucherand, Pascal; Grenet, Louis; Karst, Nicolas; Fournier, Hélène; Roux, Frédéric [CEA, LITEN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Ducroquet, Frédérique [IMEP-LAHC, Minatec, Grenoble-INP, CNRS UMR 5130, 38016 Grenoble (France); Brioude, Arnaud [Laboratoire des Multimatériaux et Interfaces, UMR 5615, Villeurbanne (France); Perraud, Simon [CEA, LITEN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France)

2013-12-02

Molybdenum back contact properties are critical for Cu(In,Ga)Se{sub 2} (CIGS) solar cell performance on metallic substrates. In this work, we investigated the properties of sputter-deposited Mo bilayer back contacts on Ti foils. The morphology, electrical resistivity, optical reflectance and residual mechanical stress of the bottom Mo layer were modified by varying the working pressure during its deposition. Working pressures ranging from 0.27 Pa to 4.00 Pa were used. The top Mo layer was deposited using constant conditions at a pressure of 0.13 Pa. It was demonstrated that unlike a Mo monolayer, the use of a Mo bilayer allows controlling the mechanical stress at the Mo/CIGS interface without degrading the optical reflectance and the electrical resistance of the back contact. It was also found that the morphology of the bottom Mo layer affects the growth of the top Mo layer, resulting in a modified back contact surface morphology. This induces changes in the crystalline orientation of the CIGS layer. The resulting solar cell characteristics strongly vary as a function of the bottom Mo layer deposition pressure. A bottom Mo layer growth at 2.93 Pa allows improving the solar cell conversion efficiency by 1.5 times compared to a bottom Mo layer deposited at 0.27 Pa. Using the improved Mo bilayer back contact, a maximum solar cell efficiency of 10.0% was obtained without sodium addition nor anti-reflection coating. - Highlights: • Mo bilayer back contacts for Cu(In,Ga)Se{sub 2} solar cells were grown on Ti substrates. • The sputtering pressure of the bottom Mo layer was varied between 0.27 Pa and 4 Pa. • The top Mo layer controls the optical and electrical properties of the back contact. • The structure of the bottom Mo layer influences the morphology of the top Mo layer. • The back contact affects the CIGS texture, device series resistance and efficiency.

EFFECTS OF THE BACK-FILLING TO THE STABILITY OF A CAISSON

Science.gov (United States)

Kikuchi, Yoshiaki; Shinsha, Hiroshi; Kawamura, Kensuke; Eguchi, Shinya

The back-filling improves the stability of a caisson used for breakwater against wave force. But, the extent of the improvement of the stability is affected by the interaction among the back-filling and the caisson and the foundation. A series of the model loading experiments was carried out to clarify the effects of the interaction to the stability. In this series of experiments, horizontal static load was applied to the model caisson having back-filling. Sliding failure surface was estimated from the deformation of rubble mound and back-filling. Passive earth pressure by back-filling calculated by wedge theory was compared with the experimental results. New stability evaluation method considering circular arc failure mode was developed and evaluated its validity. Followings are main conclusions in this research; 1) Increment of stability of a caisson against wave force can be estimated from wedge theory. 2) Both sliding and bearing capacity stability were considered in one time using newly developed evaluation method considering circular arc failure mode.

Back pain and low back pain

International Nuclear Information System (INIS)

Cotta, H.; Niethard, F.U.

1983-01-01

In patients with back pain there is only a poor correlation between clinical and radiological symptoms. Therefore the interpretation of radiological findings is only possible with respect to the natural history of the disease. Indication for radiological examination is given for early diagnosis and treatment of malinformation of the spine; diagnosis and treatment of functional disturbances of the spine with back- and low back pain and diagnosis and treatment of diseases which affect the stability of the vertebrae. (orig.)

The effect of Kinesio Taping on postural control in subjects with non-specific chronic low back pain.

Science.gov (United States)

Abbasi, Soheila; Rojhani-Shirazi, Zahra; Shokri, Esmaeil; García-Muro San José, Francisco

2018-04-01

The aim of this study was to investigate the possible alterations in postural control during upright standing in subjects with non-specific chronic low back pain and the effect of Kinesio taping on the postural control. Twenty subjects with non-specific chronic low back pain and twenty healthy subjects participated in this study. The center of pressure excursion was evaluated before the intervention for both groups, and immediately after intervention for the low back pain group. Independent sample t-test, Mann-Whitney test and repeated measure ANOVA were used for the statistical analysis of the data. There were significant differences in the center of pressure excursion between the low back pain group versus the healthy group. The results of the ANOVA demonstrated a statistically significant difference in the mean COP displacement and velocity before Kinesio Taping, immediately after, and 24 h after in the low back pain group. There are poor postural control mechanisms in subjects with non-specific chronic low back pain. Kinesio taping seems to change postural control immediately and have lasting effects until the day after. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tensile strength of Zr-2.5 Nb pressure tubes: A statistical study

Energy Technology Data Exchange (ETDEWEB)

Shah, Priti Kotak, E-mail: pritik@barc.gov.in [Senior Scientist, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Dubey, J.S.; Datta, D.; Shriwastaw, R.S.; Rath, B.N.; Singh, R.N. [Senior Scientist, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Anantharaman, S. [Head, Post Irradiation Examination Division, Bhabha Atomic Research Centre, Mumbai (India); Chakravartty, J.K. [Director, Materials Group, Bhabha Atomic Research Centre, Mumbai (India)

2015-12-15

Highlights: • Tensile properties in axial and transverse direction for a number of Indian Zr-2.5 Nb PHWR pressure tubes. • Distribution of tensile properties of double-melted and quadruple-melted pressure tubes. • Tensile properties at front-end and back-end of the quadruple melted pressure tubes at room temperature and at 300 °C. - Abstract: In order to get an idea of the statistical variation in the tensile properties of the double-melted as well as quadruple melted Zr-2.5 Nb pressure tubes (PTs) and also the variation in tensile properties between the two ends of the pressure tubes, tension tests were carried out on around 50 pressure tube off-cuts. Longitudinal and transverse tensile specimens were prepared from these off-cuts of pressure tubes of double-melted and quadruple melted types. For quadruple melted pressure tubes the specimens were tested from both front-end and back-end off-cuts. Miniature flat tensile specimens having 1.8 mm width and 1.5 mm thickness and 7.6 mm gauge length were prepared from the pressure tube off-cuts without any flattening treatment. Tension tests were carried out in a screw-driven machine at room temperature and 300 °C for both front-end and back-end off-cuts of each of 16 pressure tubes. In general the transverse specimens showed higher yield strength (YS) and ultimate tensile strength (UTS) compared to the longitudinal specimens. Transverse specimens showed less strain hardening compared to the longitudinal specimens. The axial specimens showed higher uniform (UE) and total elongation (TE) compared to the transverse specimens. Double-melted pressure tubes showed relatively higher strength and lower elongation and larger standard deviation compared to the quadruple melted pressure tubes. Mean values of tensile properties showed that back-end off-cuts were relatively stronger and less ductile compared to the front-end off-cuts.

Forward coronary flow normally seen in systole is the result of both forward and concealed back flow

NARCIS (Netherlands)

Spaan, J. A.; Breuls, N. P.; Laird, J. D.

1981-01-01

Normally systolic coronary blood flow is almost entirely forward. As perfusion pressure was lowered through the autoregulatory range in open-chest dogs, net systolic back flow appeared at approximately 70 mm Hg. Imposing a series resistance (Rs), which impedes both forward and back flow, abolished

Waves of change - the dynamics of institutional pressures

NARCIS (Netherlands)

Klein Woolthuis, R.J.A.; Taminiau, Yvette

2017-01-01

This article coins additional explanations for organizations’ room for agency and institutional change by bringing all institutional and competitive pressures back into institutional theory, and by introducing theory on how the interaction between these pressures leads to novelty, contradictions,

[Gender features of low back pain syndromes].

Science.gov (United States)

Moseĭkin, I A; Goĭdenko, V S; Aleksandrov, V I; Rudenko, I V; Borzunova, T A; Barashkov, G N

2010-01-01

Forty-four patients with low back pain caused by a radix syndrome (mean age 46.18±9.11 years) have been examined. Patients have been stratified by sex. The pain syndrome has been assessed in 1st, 10th and 21st by the VAS, pressure pain measurement and laboratory tests for measuring neurotransmitter levels. It has been shown that women endure a pain worse as assessed not only by the questionnaires but also by the pressure pain measurement especially at night. The analysis of blood serum revealed higher levels of β-endorphin, serotonin, dopamine that were correlated (р<0.05) with the pain level, their amount decreasing with the reduction of pain.

Chronic Widespread Back Pain is Distinct From Chronic Local Back Pain: Evidence From Quantitative Sensory Testing, Pain Drawings, and Psychometrics.

Science.gov (United States)

Gerhardt, Andreas; Eich, Wolfgang; Janke, Susanne; Leisner, Sabine; Treede, Rolf-Detlef; Tesarz, Jonas

2016-07-01

Whether chronic localized pain (CLP) and chronic widespread pain (CWP) have different mechanisms or to what extent they overlap in their pathophysiology is controversial. The study compared quantitative sensory testing profiles of nonspecific chronic back pain patients with CLP (n=48) and CWP (n=29) with and fibromyalgia syndrome (FMS) patients (n=90) and pain-free controls (n = 40). The quantitative sensory testing protocol of the "German-Research-Network-on-Neuropathic-Pain" was used to measure evoked pain on the painful area in the lower back and the pain-free hand (thermal and mechanical detection and pain thresholds, vibration threshold, pain sensitivity to sharp and blunt mechanical stimuli). Ongoing pain and psychometrics were captured with pain drawings and questionnaires. CLP patients did not differ from pain-free controls, except for lower pressure pain threshold (PPT) on the back. CWP and FMS patients showed lower heat pain threshold and higher wind-up ratio on the back and lower heat pain threshold and cold pain threshold on the hand. FMS showed lower PPT on back and hand, and higher comorbidity of anxiety and depression and more functional impairment than all other groups. Even after long duration CLP presents with a local hypersensitivity for PPT, suggesting a somatotopically specific sensitization of nociceptive processing. However, CWP patients show widespread ongoing pain and hyperalgesia for different stimuli that is generalized in space, suggesting the involvement of descending control systems, as also suggested for FMS patients. Because mechanisms in nonspecific chronic back pain with CLP and CWP differ, these patients should be distinguished in future research and allocated to different treatments.

Low back pain - acute

Science.gov (United States)

Backache; Low back pain; Lumbar pain; Pain - back; Acute back pain; Back pain - new; Back pain - short-term; Back strain - new ... lower back supports most of your body's weight. Low back pain is the number two reason that Americans see ...

Is standing balance altered in individuals with chronic low back pain? A systematic review.

Science.gov (United States)

Berenshteyn, Yevgeniy; Gibson, Kelsey; Hackett, Gavin C; Trem, Andrew B; Wilhelm, Mark

2018-01-30

To examine the static standing balance of individuals with chronic low back pain when compared to a healthy control group. A search of available literature was done using PubMed, SPORTDiscus, CINAHL, and Scopus databases. Studies were included if they contained the following: (1) individuals with chronic low back pain 3 months or longer; (2) healthy control group; (3) quantified pain measurement; and (4) center of pressure measurement using a force plate. Two authors independently reviewed articles for inclusion, and assessed for quality using the Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross Sectional Studies. Cohen's d effect size was calculated to demonstrate the magnitude of differences between groups. Nine articles were included in this review. Quality scores ranged from 5/8 to 8/8. Although center of pressure measures were nonhomogeneous, subjects with chronic low back pain had poorer performance overall compared to healthy controls. Despite inconsistencies in statistical significance, effect sizes were frequently large, indicating a lack of sufficient power in the included studies. Data were insufficiently reported among certain studies, limiting the ability of direct study comparison. Results suggest that balance is impaired in individuals with chronic low back pain when compared to healthy individuals. Implications for rehabilitation Static balance is affected in individuals with chronic low back pain. Balance assessments should be completed for individuals with chronic low back pain. Results from balance assessments should be used to indicate areas of improvement and help guide the course of treatment, as well as reassess as treatment progresses.

Investigation of the on-axis atom number density in the supersonic gas jet under high gas backing pressure by simulation

Directory of Open Access Journals (Sweden)

Guanglong Chen

2015-10-01

Full Text Available The supersonic gas jets from conical nozzles are simulated using 2D model. The on-axis atom number density in gas jet is investigated in detail by comparing the simulated densities with the idealized densities of straight streamline model in scaling laws. It is found that the density is generally lower than the idealized one and the deviation between them is mainly dependent on the opening angle of conical nozzle, the nozzle length and the gas backing pressure. The density deviation is then used to discuss the deviation of the equivalent diameter of a conical nozzle from the idealized deq in scaling laws. The investigation on the lateral expansion of gas jet indicates the lateral expansion could be responsible for the behavior of the density deviation. These results could be useful for the estimation of cluster size and the understanding of experimental results in laser-cluster interaction experiments.

Pressure-Application Device for Testing Pressure Sensors

Science.gov (United States)

2002-01-01

A portable pressure-application device has been designed and built for use in testing and calibrating piezoelectric pressure transducers in the field. The device generates pressure pulses of known amplitude. A pressure pulse (in contradistinction to a steady pressure) is needed because in the presence of a steady pressure, the electrical output of a piezoelectric pressure transducer decays rapidly with time. The device includes a stainless- steel compressed-air-storage cylinder of 500 cu cm volume. A manual hand pump with check valves and a pressure gauge are located at one end of the cylinder. A three-way solenoid valve that controls the release of pressurized air is located at the other end of the cylinder. Power for the device is provided by a 3.7-V cordless-telephone battery. The valve is controlled by means of a pushbutton switch, which activates a 5 V to +/-15 V DC-to-DC converter that powers the solenoid. The outlet of the solenoid valve is connected to the pressure transducer to be tested. Before the solenoid is energized, the transducer to be tested is at atmospheric pressure. When the solenoid is actuated by the push button, pressurized air from inside the cylinder is applied to the transducer. Once the pushbutton is released, the cylinder pressure is removed from the transducer and the pressurized air applied to the transducer is vented, bringing the transducer back to atmospheric pressure. Before this device was used for actual calibration, its accuracy was checked with a NIST (National Institute of Standards and Technology) traceable calibrator and commercially calibrated pressure transducers. This work was done by Wanda Solano of Stennis Space Center and Greg Richardson of Lockheed Martin Corp.

Aluminum–Titanium Alloy Back Contact Reducing Production Cost of Silicon Thin-Film Solar Cells

Directory of Open Access Journals (Sweden)

Hsin-Yu Wu

2016-11-01

Full Text Available In this study, metal films are fabricated by using an in-line reactive direct current magnetron sputtering system. The aluminum–titanium (AlTi back contacts are prepared by changing the pressure from 10 mTorr to 25 mTorr. The optical, electrical and structural properties of the metal back contacts are investigated. The solar cells with the AlTi had lower contact resistance than those with the silver (Ag back contact, resulting in a higher fill factor. The AlTi contact can achieve a solar cell conversion efficiency as high as that obtained from the Ag contact. These findings encourage the potential adoption of AlTi films as an alternative back contact to silver for silicon thin-film solar cells.

Reduced task-induced variations in the distribution of activity across back muscle regions in individuals with low back pain.

Science.gov (United States)

Falla, Deborah; Gizzi, Leonardo; Tschapek, Marika; Erlenwein, Joachim; Petzke, Frank

2014-05-01

This study investigated change in the distribution of lumbar erector spinae muscle activity and pressure pain sensitivity across the low back in individuals with low back pain (LBP) and healthy controls. Surface electromyographic (EMG) signals were recorded from multiple locations over the lumbar erector spinae muscle with a 13×5 grid of electrodes from 19 people with chronic nonspecific LBP and 17 control subjects as they performed a repetitive lifting task. The EMG root mean square (RMS) was computed for each location of the grid to form a map of the EMG amplitude distribution. Pressure pain thresholds (PPT) were recorded before and after the lifting task over a similar area of the back. For the control subjects, the EMG RMS progressively increased more in the caudal region of the lumbar erector spinae during the repetitive task, resulting in a shift in the distribution of muscle activity. In contrast, the distribution of muscle activity remained unaltered in the LBP group despite an overall increase in EMG amplitude. PPT was lower in the LBP group after completion of the repetitive task compared to baseline (average across all locations: pre: 268.0±165.9 kPa; post: 242.0±166.7 kPa), whereas no change in PPT over time was observed for the control group (320.1±162.1 kPa; post: 322.0±179.5 kPa). The results demonstrate that LBP alters the normal adaptation of lumbar erector spinae muscle activity to exercise, which occurs in the presence of exercise-induced hyperalgesia. Reduced variability of muscle activity may have important implications for the provocation and recurrence of LBP due to repetitive tasks. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Understanding cultural influences on back pain and back pain research.

Science.gov (United States)

Henschke, Nicholas; Lorenz, Eva; Pokora, Roman; Michaleff, Zoe A; Quartey, Jonathan N A; Oliveira, Vinicius Cunha

2016-12-01

Low back pain is highly prevalent and places a considerable burden on individuals, their families and communities. This back pain burden is unequally distributed around the world and within populations. Clinicians and researchers addressing back pain should be aware of the cultural, social and political context of back pain patients and how this context can influence pain perception, disability and health care use. Culture, which influences the beliefs and behaviour of individuals within a social group, could be considered an important contributor to the unequal distribution of back pain. However, there is paucity of high-quality research exploring the influence of culture on the experience and management of back pain. Further development and testing of specific tools, assessment methods and communication strategies are needed to improve our understanding of how cultural practices, values and identifications affect those dealing with back pain. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-pressure stainless steel active membrane microvalves

International Nuclear Information System (INIS)

Sharma, G; Svensson, S; Ogden, S; Klintberg, L; Hjort, K

2011-01-01

In this work, high-pressure membrane microvalves have been designed, manufactured and evaluated. The valves were able to withstand back-pressures of 200 bar with a response time of less than 0.6 s. These stainless steel valves, manufactured with back-end batch production, utilize the large volume expansion coupled to the solid–liquid phase transition in paraffin wax. When membrane materials were evaluated, parylene coated stainless steel was found to be the best choice as compared to polydimethylsiloxane and polyimide. Also, the influence of the orifice placement and diameter is included in this work. If the orifice is placed too close to the rim of the membrane, the valve can stay sealed even after turning the power off, and the valve will not open until the pressure in the system is released. The developed steel valves, evaluated for both water and air, provide excellent properties in terms of mechanical stability, ease of fabrication, and low cost. Possible applications include sampling at high pressures, chemical microreactors, high performance liquid chromatography, pneumatics, and hydraulics

Somatosensory nociceptive characteristics differentiate subgroups in people with chronic low back pain: a cluster analysis.

Science.gov (United States)

Rabey, Martin; Slater, Helen; OʼSullivan, Peter; Beales, Darren; Smith, Anne

2015-10-01

The objectives of this study were to explore the existence of subgroups in a cohort with chronic low back pain (n = 294) based on the results of multimodal sensory testing and profile subgroups on demographic, psychological, lifestyle, and general health factors. Bedside (2-point discrimination, brush, vibration and pinprick perception, temporal summation on repeated monofilament stimulation) and laboratory (mechanical detection threshold, pressure, heat and cold pain thresholds, conditioned pain modulation) sensory testing were examined at wrist and lumbar sites. Data were entered into principal component analysis, and 5 component scores were entered into latent class analysis. Three clusters, with different sensory characteristics, were derived. Cluster 1 (31.9%) was characterised by average to high temperature and pressure pain sensitivity. Cluster 2 (52.0%) was characterised by average to high pressure pain sensitivity. Cluster 3 (16.0%) was characterised by low temperature and pressure pain sensitivity. Temporal summation occurred significantly more frequently in cluster 1. Subgroups were profiled on pain intensity, disability, depression, anxiety, stress, life events, fear avoidance, catastrophizing, perception of the low back region, comorbidities, body mass index, multiple pain sites, sleep, and activity levels. Clusters 1 and 2 had a significantly greater proportion of female participants and higher depression and sleep disturbance scores than cluster 3. The proportion of participants undertaking Low back pain, therefore, does not appear to be homogeneous. Pain mechanisms relating to presentations of each subgroup were postulated. Future research may investigate prognoses and interventions tailored towards these subgroups.

Root-Contact/Pressure-Plate Assembly For Hydroponic System

Science.gov (United States)

Morris, Carlton E.; Loretan, Philip A.; Bonsi, Conrad K.; Hill, Walter A.

1994-01-01

Hydroponic system includes growth channels equipped with rootcontact/pressure-plate assemblies. Pump and associated plumbing circulate nutrient liquid from reservoir, along bottom of growth channels, and back to reservoir. Root-contact/pressure-plate assembly in each growth channel stimulates growth of roots by applying mild contact pressure. Flat plate and plate connectors, together constitute pressure plate, free to move upward to accommodate growth of roots. System used for growing sweetpotatoes and possibly other tuber and root crops.

Relationship between workload and low back pain in assembly line workers

Directory of Open Access Journals (Sweden)

Reza Kalantari

2016-06-01

Full Text Available Introduction: Work pressure and excessive workload can jeopardize and impair the people’s health. One of these impairments is musculoskeletal disorders. Among these disorders, low back pain is the most common and most costly problem. The purpose of this study was to investigate the relationship between workload and prevalence of low back pain in assembly line workers of a car manufacturing factory. Methods: This cross-sectional study was conducted on 69 workers working in the assembly line of a factory. Data collection tools included three questionnaires: demographic questionnaire, NASA Task Load Index (NASA-TLX and Cornell Musculoskeletal Discomfort Questionnaire (CMDQ. Data were analyzed by descriptive and inferential (T-test and One-way ANOVA statistics. Results: Of the workers, 72.5% were female. The average total workload was 71.42% and the prevalence of musculoskeletal disorders in low back was 43.37%. The results of the analysis of relationship between workload and the prevalence of low back pain showed a significant relationship between physical/ mental workload and the incidence of low back pain (P<0.05. Conclusion: The more is the workload on the person, the greater is the risk of low back pain. Measures such as increasing the number of workers to distribute the workload, slowing the work pace, having work-rest periods for workers, improving psychological conditions of work, etc. can be useful in this regard.

Mitigating IPMC back relaxation through feedforward and feedback control of patterned electrodes

International Nuclear Information System (INIS)

Fleming, Maxwell J; Leang, Kam K; Kim, Kwang J

2012-01-01

With low driving voltage ( < 5 V) and the ability to be operated in aqueous environments, ionic polymer–metal composite (IPMC) materials are quickly gaining attention for use in many applications including soft bio-inspired actuators and sensors. There are, however, drawbacks to IPMC actuators, including the ‘back relaxation’ effect. Specifically, when subjected to an excessively slow input, the IPMC actuator will slowly relax back toward its original position. There is debate over the physical mechanism of back relaxation, although one prevalent theory describes an initial current, caused by the electrostatic forces of the charging electrodes, which drives water molecules across the ion exchange membrane and deforms the IPMC. Once the electrodes are fully charged, however, the dominant element of the motion is the osmotic pressure, driving the water molecules back to equilibrium, thus causing back relaxation. A new method to mitigate back relaxation is proposed, taking advantage of controlled activation of patterned (sectored) electrodes on the IPMC. By actuating sectors in opposing directions, back relaxation can be effectively canceled out. An integrated feedforward and feedback controller is employed based on this concept, and is shown to minimize back relaxation, while reducing the input voltage required, as compared to the case of the non-sectored IPMC. Experimental results show nearly an order of magnitude reduction in the tracking error compared to the uncompensated case, and that the IPMC’s position can be maintained over a period of 60 and 1200 s with minimal evidence of back relaxation. (paper)

Low pressure lithium condensation

International Nuclear Information System (INIS)

Wadkins, R.P.; Oh, C.H.

1985-01-01

A low pressure experiment to evaluate the laminar film condensation coefficients of lithium was conducted. Some thirty-six different heat transfer tests were made at system pressures ranging from 1.3 to 26 Pa. Boiled lithium was condensed on the inside of a 7.6-cm (ID), 409 stainless-steel pipe. Condensed lithium was allowed to reflux back to the pool boiling region below the condensing section. Fourteen chromel/alumel thermocouples were attached in various regions of the condensing section. The thermocouples were initially calibrated with errors of less than one degree Celsius

The effect of chronic low back pain on tactile suppression during back movements.

Science.gov (United States)

Van Damme, Stefaan; Van Hulle, Lore; Danneels, Lieven; Spence, Charles; Crombez, Geert

2014-10-01

The aim of the present study was to examine whether tactile suppression, the phenomenon whereby tactile perception is suppressed during movement, would occur in the context of back movements. Of particular interest, it was investigated if tactile suppression in the back would be attenuated in those suffering from chronic low back pain. Individuals with chronic low back pain (N = 30) and a matched control group (N = 24) detected tactile stimuli on three possible locations (back, arm, chest) while performing a back or arm movement, or no movement. We hypothesized that the movements would induce tactile suppression, and that this effect would be largest for low-intense stimuli on the moving body part. We further hypothesized that, during back movements, tactile suppression on the back would be less pronounced in the chronic low back pain group than in the control group. The results showed the expected general tactile suppression effects. The hypothesis of back-specific attenuation of tactile suppression in the chronic low back pain group was not supported. However, back-specific tactile suppression in the chronic low back pain group was less pronounced in those who performed the back movements more slowly. Copyright © 2014 Elsevier B.V. All rights reserved.

Is there a relationship between pain intensity and postural sway in patients with non-specific low back pain?

DEFF Research Database (Denmark)

Ruhe, A.; Fejer, R.; Walker, B.

2011-01-01

compared to healthy controls. In addition, regression analysis revealed a significant and linear increase in postural sway with higher pain ratings for all included COP parameters. Statistically significant changes in mean sway velocity in antero-posterior and medio-lateral direction and sway area were......Background: Increased center of pressure excursions are well documented in patients suffering from non-specific low back pain, whereby the altered postural sway includes both higher mean sway velocities and larger sway area. No investigation has been conducted to evaluate a relationship between...... pain intensity and postural sway in adults (aged 50 or less) with non-specific low back pain. Methods: Seventy-seven patients with non-specific low back pain and a matching number of healthy controls were enrolled. Center of pressure parameters were measured by three static bipedal standing tasks of 90...

Back to Back: A Focus on Reducing the Logistics Costs and Tax

Directory of Open Access Journals (Sweden)

Rogério João Lunkes

2012-06-01

Full Text Available The objective is to identify the main aspects related to the operation of Back to Back set out in international trade, which enables reduction of logistics costs and taxes. The operation of Back to Back is an excellent opportunity to increase foreign exchange gain and offer greater flexibility to commercial operations that the business requires. The methodology used in preparing this study was qualitative research according to the characteristics and nature of the problem. From the use of descriptive research study aims to demonstrate the main theoretical aspects underlying the subject in reference. This study aimed to identify the main aspects related to the operation of Back to Back set out in international trade and tax effects in an organization and logistics of industrial electronics segment of the State of Santa Catarina. The study demonstrated that the benefits of the operation of Back to Back is of paramount importance for companies having a positive impact in financial terms by reducing the need for tax payments and logistics costs which affect the processes of import and export. The results presented showed that the company studied the operation of Back to Back is essential for international negotiations.

Effect of thoracic mobilization on respiratory parameters in chronic non-specific low back pain: A randomized controlled trial.

Science.gov (United States)

Babina, R; Mohanty, P P; Pattnaik, M

2016-02-19

Altered respiratory function has been found to be associated with back pain. Limited chest excursion in subjects with chronic low back pain (CLBP) may be due to co-contraction or bracing of erector spinae and abdominal muscles; their flexed spinal posture; and/or their compromised spinal stability resulting from dysfunctional transversus abdominis. To check for the effects of thoracic mobilization on respiratory parameters in subjects with chronic non-specific low back pain. Sixty-two subjects (excluding 11 dropouts) with CLBP of age group 30-60 were randomly allocated to two groups. Both groups received individualized treatment for low back pain (LBP) and HEP (home exercise program) regime of breathing exercises. In addition, group 1 received Maitland's Central postero-anterior vertebral pressure for thoracic spine (T1-T8). Total treatment duration was 10 sessions in 2 weeks (5 sessions/week). Results showed significant improvement in respiratory parameters viz. Forced Vital Capacity (FVC), Sustained Maximal Inspiratory Pressure (SMIP) and Chest Wall Expansion (CWE) and Oswestry Disability Index (ODI) in both groups (pchronic low back pain with or without radiation to lower limbs when treated with thoracic central PA mobilization, in addition to LBP specific treatment and breathing exercises, show an improvement in respiratory parameters and reduction in disability.

Tensile properties of quadruple melted Zr-2.5Nb pressure tubes evaluated from pressure tube offcuts

International Nuclear Information System (INIS)

Shah, Priti Kotak; Dubey, J.S.; Anantharaman, S.

2013-12-01

Rajasthan Atomic Power Station-2 (RAPS-2) is the first Pressurised Heavy Water Reactor (PHWR) in India having quadruple melted Zr-2.5Nb pressure tubes. Front-end and back-end off-cuts of sixteen pressure tubes were selected for studying the mechanical properties in axial and transverse directions of the tube. Tension tests were carried out at room temperature and at 300℃ using miniature tensile test specimens. The report presents the experimental details and discusses the base line tensile property data for the quadruple melted pressure tubes of RAPS-2. This data will be useful for the reactor life management. (author)

Back Pain During Pregnancy

Science.gov (United States)

... Advocacy For Patients About ACOG Back Pain During Pregnancy Home For Patients Search FAQs Back Pain During ... FAQ115, January 2016 PDF Format Back Pain During Pregnancy Pregnancy What causes back pain during pregnancy? How ...

Active control of turbulent boundary layer-induced sound transmission through the cavity-backed double panels

Science.gov (United States)

Caiazzo, A.; Alujević, N.; Pluymers, B.; Desmet, W.

2018-05-01

This paper presents a theoretical study of active control of turbulent boundary layer (TBL) induced sound transmission through the cavity-backed double panels. The aerodynamic model used is based on the Corcos wall pressure distribution. The structural-acoustic model encompasses a source panel (skin panel), coupled through an acoustic cavity to the radiating panel (trim panel). The radiating panel is backed by a larger acoustic enclosure (the back cavity). A feedback control unit is located inside the acoustic cavity between the two panels. It consists of a control force actuator and a sensor mounted at the actuator footprint on the radiating panel. The control actuator can react off the source panel. It is driven by an amplified velocity signal measured by the sensor. A fully coupled analytical structural-acoustic model is developed to study the effects of the active control on the sound transmission into the back cavity. The stability and performance of the active control system are firstly studied on a reduced order model. In the reduced order model only two fundamental modes of the fully coupled system are assumed. Secondly, a full order model is considered with a number of modes large enough to yield accurate simulation results up to 1000 Hz. It is shown that convincing reductions of the TBL-induced vibrations of the radiating panel and the sound pressure inside the back cavity can be expected. The reductions are more pronounced for a certain class of systems, which is characterised by the fundamental natural frequency of the skin panel larger than the fundamental natural frequency of the trim panel.

Differences in Pain Processing Between Patients with Chronic Low Back Pain, Recurrent Low Back Pain, and Fibromyalgia.

Science.gov (United States)

Goubert, Dorien; Danneels, Lieven; Graven-Nielsen, Thomas; Descheemaeker, Filip; Meeus, Mira

2017-05-01

The impairment in musculoskeletal structures in patients with low back pain (LBP) is often disproportionate to their complaint. Therefore, the need arises for exploration of alternative mechanisms contributing to the origin and maintenance of non-specific LBP. The recent focus has been on central nervous system phenomena in LBP and the pathophysiological mechanisms underlying the various symptoms and characteristics of chronic pain. Knowledge concerning changes in pain processing in LBP remains ambiguous, partly due to the diversity in the LBP population. The purpose of this study is to compare quantitative sensory assessment in different groups of LBP patients with regard to chronicity. Recurrent low back pain (RLBP), mild chronic low back pain (CLBP), and severe CLBP are compared on the one hand with healthy controls (HC), and on the other hand with fibromyalgia (FM) patients, in which abnormal pain processing has previously been reported. Cross-sectional study. Department of Rehabilitation Sciences, Ghent University, Belgium. Twenty-three RLBP, 15 mild CLBP, 16 severe CLBP, 26 FM, and 21 HC participated in this study. Quantitative sensory testing was conducted by manual pressure algometry and computer-controlled cuff algometry. A manual algometer was used to evaluate hyperalgesia as well as temporal summation of pain and a cuff algometer was used to evaluate deep tissue hyperalgesia, the efficacy of the conditioned pain modulation and spatial summation of pain. Pressure pain thresholds by manual algometry were significantly lower in FM compared to HC, RLBP, and severe CLBP. Temporal summation of pain was significantly higher in FM compared to HC and RLBP. Pain tolerance thresholds assessed by cuff algometry were significantly lower in FM compared to HC and RLBP and also in severe CLBP compared to RLBP. No significant differences between groups were found for spatial summation or conditioned pain modulation. No psychosocial issues were taken into account for this

Hg+ ion density in low-pressure Ar-Hg discharge plasma used for liquid crystal display back-lighting

International Nuclear Information System (INIS)

Goto, Miki; Arai, Toshihiko

1995-01-01

The positive column of a low-pressure Ar-Hg discharge has been applied as a fluorescent light source for illumination. Many studies on the diagnostics and fundamental mechanisms have been carried out on both the classical fluorescent lamp (d=36 mm) and the compact fluorescent lamp (d=12 mm). On the other hand, a lamp of extremely narrow diameter (usually below 6 mm) has been recently developed for liquid crystal display (LCD) back-lighting and its importance is undoubtedly increasing. Some characteristics or mechanisms of the narrow-diameter lamp may be similar to those of the 36 mm one; however the similarity rule does not hold between them due to the contributions from a stepwise ionization process. Therefore, in order to clarify the excitation mechanism in the narrow-diameter lamp quantitatively, various parameters must be measured directly and some analysis must be done. The Hg + ion density and electron density are important parameters for the purpose of clarifying the excitation mechanism quantitatively. In this work, we have measured the Hg + ion density using the modified absorption method, and the electron density using the probe method in the Ar-Hg discharge of the 4 mm bore tube on bath temperature. Moreover, with combining the modified absorption method and the probe method, the Hg 2 + molecular ion density has been determined

Expansion Effects on Back-to-Back Correlations

International Nuclear Information System (INIS)

Padula, S.S.; Krein, G.; Csoergo, T.; Hama, Y.; Panda, P.K.

2004-01-01

The back-to-back correlations (BBC) of particle-antiparticle pairs, signalling in-medium mass modification, are studied in a finite size thermalized medium. The width of BBC function is explicitly evaluated in the case of a nonrelativistic spherically symmetric expanding fireball. The effect of the flow is to reduce the BBC signal as compared to the case of non flow. Nevertheless, a significant signal survives finite-time emission plus expansion effects

Back Schools for chronic non-specific low back pain.

Science.gov (United States)

Parreira, Patrícia; Heymans, Martijn W; van Tulder, Maurits W; Esmail, Rosmin; Koes, Bart W; Poquet, Nolwenn; Lin, Chung-Wei Christine; Maher, Christopher G

2017-08-03

Many people with low back pain (LBP) become frequent users of healthcare services in their attempt to find treatments that minimise the severity of their symptoms. Back School consists of a therapeutic programme given to groups of people that includes both education and exercise. However, the content of Back School has changed over time and appears to vary widely today. This review is an update of a Cochrane review of randomised controlled trials (RCTs) evaluating the effectiveness of Back School. We split the Cochrane review into two reviews, one focusing on acute and subacute LBP, and one on chronic LBP. The objective of this systematic review was to determine the effect of Back School on pain and disability for adults with chronic non-specific LBP; we included adverse events as a secondary outcome. In trials that solely recruited workers, we also examined the effect on work status. We searched for trials in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, two other databases and two trials registers to 15 November 2016. We also searched the reference lists of eligible papers and consulted experts in the field of LBP management to identify any potentially relevant studies we may have missed. We placed no limitations on language or date of publication. We included only RCTs and quasi-RCTs evaluating pain, disability, and/or work status as outcomes. The primary outcomes for this update were pain and disability, and the secondary outcomes were work status and adverse events. Two review authors independently performed the 'Risk of bias' assessment of the included studies using the 'Risk of bias' assessment tool recommended by The Cochrane Collaboration. We summarised the results for the short-, intermediate-, and long-term follow-ups. We evaluated the overall quality of evidence using the GRADE approach. For the outcome pain, at short-term follow-up, we found very low-quality evidence that Back School is more effective than no

Expansion effects on back-to-back correlations

Energy Technology Data Exchange (ETDEWEB)

Padula, S.S.; Krein, G. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil)]. E-mail: padula@ift.unesp.br; Csoerg, T.; Panda, P.K. [Central Research Institute for Physics (KFKI), Budapest (Hungary). Research Institute for Particle and Nuclear Physics (RMKI); Hama, Y. [Santa Catarina Univ., Florianopolis, SC (Brazil). Centro de Ciencias Fisicas e Matematicas. Dept. de Fisica

2004-07-01

The back-to-back correlations (BBC) of particle-antiparticle pairs, signalling in-medium mass modification, are studied in a finite size thermalized medium. The width of BBC function is explicitly evaluated in the case of a nonrelativistic spherically symmetric expanding fireball. The effect of the flow is to reduce the BBC signal as compared to the case of non flow. Nevertheless, a significant signal survives finite-time emission plus expansion effects. (author)

Expansion effects on back-to-back correlations

International Nuclear Information System (INIS)

Padula, S.S.; Krein, G.; Csoerg, T.; Panda, P.K.; Hama, Y.

2004-01-01

The back-to-back correlations (BBC) of particle-antiparticle pairs, signalling in-medium mass modification, are studied in a finite size thermalized medium. The width of BBC function is explicitly evaluated in the case of a nonrelativistic spherically symmetric expanding fireball. The effect of the flow is to reduce the BBC signal as compared to the case of non flow. Nevertheless, a significant signal survives finite-time emission plus expansion effects. (author)

Negative beliefs about low back pain are associated with persistent high intensity low back pain.

Science.gov (United States)

Ng, Sin Ki; Cicuttini, Flavia M; Wang, Yuanyuan; Wluka, Anita E; Fitzgibbon, Bernadette; Urquhart, Donna M

2017-08-01

While previous cross-sectional studies have found that negative beliefs about low back pain are associated with pain intensity, the relationship between back beliefs and persistent low back pain is not well understood. This cohort study aimed to examine the role of back beliefs in persistent low back pain in community-based individuals. A hundred and ninety-two participants from a previous musculoskeletal health study were invited to take part in a two-year follow-up study. Beliefs about back pain were assessed by the Back Beliefs Questionnaire (BBQ) at baseline and low back pain intensity was measured by the Chronic Pain Grade Questionnaire at baseline and follow-up. Of the 150 respondents (78.1%), 16 (10.7%) reported persistent high intensity low back pain, 12 (8.0%) developed high intensity low back pain, in 16 (10.7%) their high intensity low back pain resolved and 106 (70.7%) experienced no high intensity low back pain. While participants were generally positive about low back pain (BBQ mean (SD) = 30.2 (6.4)), those with persistent high intensity pain reported greater negativity (BBQ mean (SD) = 22.6 (4.9)). Negative beliefs about back pain were associated with persistent high intensity low back pain after adjusting for confounders (M (SE) = 23.5 (1.6) vs. >30.1 (1.7), p back beliefs were associated with persistent high intensity low back pain over 2 years in community-based individuals. While further longitudinal studies are required, these findings suggest that targeting beliefs in programs designed to treat and prevent persistent high intensity low back pain may be important.

Making a Back-Illuminated Imager with Back-Side Contact and Alignment Markers

Science.gov (United States)

Pain, Bedabrata

2008-01-01

A design modification and a fabrication process that implements the modification have been conceived to solve two problems encountered in the development of back-illuminated, back-sidethinned complementary metal oxide/ semiconductor (CMOS) image-detector integrated circuits. The two problems are (1) how to form metal electrical-contact pads on the back side that are electrically connected through the thickness in proper alignment with electrical contact points on the front side and (2) how to provide alignment keys on the back side to ensure proper registration of backside optical components (e.g., microlenses and/or color filters) with the front-side pixel pattern. The essence of the design modification is to add metal plugs that extend from the desired front-side locations through the thickness and protrude from the back side of the substrate. The plugs afford the required front-to-back electrical conduction, and the protrusions of the plugs serve as both the alignment keys and the bases upon which the back-side electrical-contact pads can be formed.

Critical pressure of non-equilibrium two-phase critical flow

Energy Technology Data Exchange (ETDEWEB)

Minzer, U [Israel Electric Corp. Ltd., Haifa (Israel)

1996-12-01

Critical pressure is defined as the pressure existing at the exit edge of the piping, when it remains constant despite a decrease in the back. According to this definition the critical pressure is larger than the back pressure and for two-phase conditions below saturation pressure. The two-phase critical pressure has a major influence on the two-phase critical flow characteristics. Therefore it is of High significance in calculations of critical mass flux and critical depressurization rate, which are important in the fields of Nuclear Reactor Safety and Industrial Safety. At the Nuclear Reactor Safety field is useful for estimations of the Reactor Cooling System depressurization, the core coolant level, and the pressure build-up in the containment. In the Industrial Safety field it is helpful for estimating the leakage rate of toxic gases Tom liquefied gas pressure vessels, depressurization of pressure vessels, and explosion conditions due to liquefied gas release. For physical description of non-equilibrium two-phase critical flow it would be convenient to divide the flow into two stages. The first stage is the flow of subcooled liquid at constant temperature and uniform pressure drop (i.e., the case of incompressible fluid and uniform piping cross section). The rapid flow of the liquid causes a delay in the boiling of the liquid, which begins to boil below saturation pressure, at thermal non-equilibrium. The boiling is the beginning of the second stage, characterized by a sharp increase of the pressure drop. The liquid temperature on the second stage is almost constant because most of the energy for vaporization is supplied from the large pressure drop The present work will focus on the two-phase critical pressure of water, since water serves as coolant in the vast majority of nuclear power reactors throughout the world. (author).

Critical pressure of non-equilibrium two-phase critical flow

International Nuclear Information System (INIS)

Minzer, U.

1996-01-01

Critical pressure is defined as the pressure existing at the exit edge of the piping, when it remains constant despite a decrease in the back. According to this definition the critical pressure is larger than the back pressure and for two-phase conditions below saturation pressure. The two-phase critical pressure has a major influence on the two-phase critical flow characteristics. Therefore it is of High significance in calculations of critical mass flux and critical depressurization rate, which are important in the fields of Nuclear Reactor Safety and Industrial Safety. At the Nuclear Reactor Safety field is useful for estimations of the Reactor Cooling System depressurization, the core coolant level, and the pressure build-up in the containment. In the Industrial Safety field it is helpful for estimating the leakage rate of toxic gases Tom liquefied gas pressure vessels, depressurization of pressure vessels, and explosion conditions due to liquefied gas release. For physical description of non-equilibrium two-phase critical flow it would be convenient to divide the flow into two stages. The first stage is the flow of subcooled liquid at constant temperature and uniform pressure drop (i.e., the case of incompressible fluid and uniform piping cross section). The rapid flow of the liquid causes a delay in the boiling of the liquid, which begins to boil below saturation pressure, at thermal non-equilibrium. The boiling is the beginning of the second stage, characterized by a sharp increase of the pressure drop. The liquid temperature on the second stage is almost constant because most of the energy for vaporization is supplied from the large pressure drop The present work will focus on the two-phase critical pressure of water, since water serves as coolant in the vast majority of nuclear power reactors throughout the world. (author)

Back pain and sports

Science.gov (United States)

... Running - back pain; Weightlifting - back pain; Lumbar pain - sports; Sciatica - sports; Low back pain - sports ... MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine: Principles and Practice . 4th ed. Philadelphia, PA: ...

People with low back pain perceive needs for non-biomedical services in workplace, financial, social and household domains: a systematic review.

Science.gov (United States)

Chou, Louisa; Cicuttini, Flavia M; Urquhart, Donna M; Anthony, Shane N; Sullivan, Kaye; Seneviwickrama, Maheeka; Briggs, Andrew M; Wluka, Anita E

2018-04-01

What needs of non-biomedical services are perceived by people with low back pain? Systematic review of qualitative and quantitative studies examining perceived needs of non-biomedical services for low back pain, identified through searching of MEDLINE, EMBASE, CINAHL and PsycINFO (1990 to 2016). Adults with low back pain of any duration. Descriptive data regarding study design and methodology were extracted. The preferences, expectations and satisfaction with non-biomedical services reported by people with low back pain were identified and categorised within areas of perceived need. Twenty studies (19 qualitative and one quantitative) involving 522 unique participants (total pool of 590) were included in this systematic review. Four areas emerged. Workplace: people with low back pain experience pressure to return to work despite difficulties with the demands of their occupation. They want their employers to be informed about low back pain and they desire workplace accommodations. Financial: people with low back pain want financial support, but have concerns about the inefficiencies of compensation systems and the stigma associated with financial remuneration. Social: people with low back pain report feeling disconnected from social networks and want back-specific social support. Household: people with low back pain report difficulties with household duties; however, there are few data regarding their need for auxiliary devices and domestic help. People with low back pain identified work place, financial and social pressures, and difficulties with household duties as areas of need beyond their healthcare requirements that affect their ability to comply with management of their condition. Consideration of such needs may inform physiotherapists, the wider health system, social networks and the workplace to provide more relevant and effective services. [Chou L, Cicuttini FM, Urquhart DM, Anthony SN, Sullivan K, Seneviwickrama M, Briggs AM, Wluka AE (2018) People with

The back-diffusion effect of air on the discharge characteristics of atmospheric-pressure radio-frequency glow discharges using bare metal electrodes

International Nuclear Information System (INIS)

Sun Wenting; Liang Tianran; Wang Huabo; Li Heping; Bao Chengyu

2007-01-01

Radio-frequency (RF), atmospheric-pressure glow discharge (APGD) plasmas using bare metal electrodes have promising prospects in the fields of plasma-aided etching, deposition, surface treatment, disinfection, sterilization, etc. In this paper, the discharge characteristics, including the breakdown voltage and the discharge voltage for sustaining a stable and uniform α mode discharge of the RF APGD plasmas are presented. The experiments are conducted by placing the home-made planar-type plasma generator in ambient and in a vacuum chamber, respectively, with helium as the primary plasma-forming gas. When the discharge processes occur in ambient, particularly for the lower plasma-working gas flow rates, the experimental measurements show that it is the back-diffusion effect of air in atmosphere, instead of the flow rate of the gas, that results in the obvious decrease in the breakdown voltage with increasing plasma-working gas flow rate. Further studies on the discharge characteristics, e.g. the luminous structures, the concentrations and distributions of chemically active species in plasmas, with different plasma-working gases or gas mixtures need to be conducted in future work

Comparison of Cooling Different Parts in a High Pressure Ratio Centrifugal Compressor

Directory of Open Access Journals (Sweden)

S. Mostafa Moosania

2016-12-01

Full Text Available Cooling in a centrifugal compressor can improve the performance and reduce the impeller temperature. In a centrifugal compressor, external walls can be cool down, which is known as the shell cooling. This method avoids undesirable effects induced by other cooling methods. Cooling can be applied on different external walls, such as the shroud, diffuser or the back plate. This paper focuses on seeking the most effective cooling place to increase the performance and reduce the impeller temperature. It is found that shroud cooling improves the compressor performance the most. Shroud cooling with 2400 W of cooling power increases the pressure ratio by 4.6% and efficiency by 1.49%. Each 500 W increase in the shroud cooling power, increases the efficiency by 0.3%. Diffuser cooling and back plate cooling have an identical effect on the polytropic efficiency. However, back plate cooling increases the pressure ratio more than diffuser cooling. Furthermore, only back plate cooling reduces the impeller temperature, and with 2400 W of cooling power, the impeller temperature reduces by 45 K.

IMPACT OF REFLEXOLOGY ON MECHANICAL LOW BACK PAIN

Directory of Open Access Journals (Sweden)

Salwa El-Gendy

2015-10-01

Full Text Available Background: Low-back pain (LBP is one of the highest common and costly musculoskeletal conditions in current society. Seventy to 85% of the populations will exhibits LBP at some time in their lives. There is little known about specific manual therapy techniques used to treat chronic LBP. Reflexology is a treatment that involves using gentle pressure to reflex points located on all of the outsides of the feet and hands. The aim of the study was to investigate the efficacy of reflexology technique in subjects with chronic low back pain (CLBP. Methods: Twenty patients with nonspecific chronic low back pain were included in the study and were assessed regarding range of motion via goniometer and pain threshold (via modified Oswestery scale and visual analogue scale, the 20 patients were allocated into two groups 10 patients in each group. Group A received reflexology sittings at rate of 3 days per week, and the duration of each sitting was 30 minutes. While group B were control. The study was continued for 3 weeks Results: According to VAS, the results revealed a non-significant variance between the study group and control group before intervention (p= 0.43. While after intervention, there was a significant decline of pain in the study group compared to that of the control group (p=0.000. Moreover, there was a very highly significant decrease in pain within the study group after treatment (p= 0.005. Conclusion: The present study indicated that the reflexology technique was effective and safe to be applied for cases of mechanical low back pain. It results in a significant decrease in pain within the study group after treatment.

φφ Back-to-Back Correlations in Finite Expanding Systems

International Nuclear Information System (INIS)

Padula, S. S.; Krein, G.; Hama, Y.; Panda, P. K.; Csoergo, T.

2006-01-01

Back-to-Back Correlations (BBC) of particle-antiparticle pairs are predicted to appear if hot and dense hadronic matter is formed in high energy nucleus-nucleus collisions. The BBC are related to in-medium mass-modification and squeezing of the quanta involved. Although the suppression of finite emission times were already known, the effects of finite system sizes and of collective phenomena had not been studied yet. Thus, for testing the survival and magnitude of the effect in more realistic situations, we study the BBC when mass-modification occurs in a finite sized, thermalized medium, considering a non-relativistically expanding fireball with finite emission time, and evaluating the width of the back-to-back correlation function. We show that the BBC signal indeed survives the expansion and flow effects, with sufficient magnitude to be observed at RHIC

Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain.

NARCIS (Netherlands)

Windt, D.A.W.M. van der; Simons, E.; Riphagen, I.I.; Ammendolia, C.; Verhangen, A.P.; Laslett, M.; Devillé, W.; Deyo, R.A.; Bouter, L.M.; Vet, H.C.W. de; Aertgeerts, B.

2010-01-01

Background: Low-back pain with leg pain (sciatica) may be caused by a herniated intervertebral disc exerting pressure on the nerve root. Most patients will respond to conservative treatment, but in carefully selected patients, surgical discectomy may provide faster relief of symptoms. Primary care

A hip abduction exercise prior to prolonged standing increased movement while reducing cocontraction and low back pain perception in those initially reporting low back pain.

Science.gov (United States)

Viggiani, Daniel; Callaghan, Jack P

2016-12-01

Persons who develop low back pain from prolonged standing exhibit increased muscle cocontraction, decreased movement and increased spine extension. However, it is unclear how these factors relate to pain development. The purpose of this study was to use hip abductor fatigue to manipulate muscle activity patterns and determine its effects on standing behaviours and pain development. Forty participants stood for two hours twice, once following a hip abductor fatigue exercise (fatigue), and once without exercise beforehand (control). Trunk and gluteal muscle activity were measured to determine cocontraction. Lumbo-pelvic angles and force plates were used to assess posture and movement strategies. Visual analog scales differentiated pain (PDs) and non-pain developers (NPDs). PDs reported less low back pain during the fatigue session, with females having earlier reductions of similar scale than males. The fatigue session reduced gluteal and trunk cocontraction and increased centre of pressure movement; male and female PDs had opposing spine posture compensations. Muscle fatigue prior to standing reduced cocontraction, increased movement during standing and reduced the low back pain developed by PDs; the timing of pain reductions depended on spine postures adopted during standing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Back Pain and Modic

DEFF Research Database (Denmark)

Manniche, Claus; Jordan, Alan; Mikkelsen, Connie

Long awaited breakthrough Approximately 25 years ago a few researchers managed to publish an article in the renowned medical journal, The Lancet. The article demonstrated that intensive exercise was most useful for patients with chronic back pain. Many of our colleagues found this difficult...... to accept, nonetheless, intensive exercise has for chronic back pain has spread across the world and has become – in different forms – the most commonly prescribed treatment for back pain patients. Since that time, there has not been much research based progress in back science, however, we have taken...... a significant step forward with the advent of the new back pain diagnosis, ”Modic changes”. During the coming years, thousands of back pain patients will now be given a precise diagnosis as well as a useful treatment in cases where we previously we unable to provide either a diagnosis or a useful treatment...

Optical fiber powered pressure sensor

International Nuclear Information System (INIS)

Schweizer, P.; Neveux, L.; Ostrowsky, D.B.

1987-01-01

In the system described, a pressure sensor and its associated electronics are optically powered by a 20 mw laser and a photovoltaic cell via an optical fiber. The sensor is periodically interrogated and sends the measures obtained back to the central unit using an LED and a second fiber. The results obtained as well as the expected evolution will be described

Strong-back safety latch

International Nuclear Information System (INIS)

DeSantis, G.N.

1995-01-01

The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch

Reorganization in Secondary Somatosensory Cortex in Chronic Low Back Pain Patients.

Science.gov (United States)

Hotz-Boendermaker, Sabina; Marcar, Valentine L; Meier, Michael L; Boendermaker, Bart; Humphreys, Barry K

2016-06-01

A cross-sectional comparative study between chronic low back pain (CLBP) patients and healthy control subjects. The aim of this study was to investigate reorganization in the sensory cortex by comparing cortical activity due to mechanosensory stimulation of the lumbar spine in CLBP patients versus a control group by using functional magnetic resonance imaging (fMRI). LBP is now the number 1 condition across the world in terms of years living with a disability. There is growing evidence that maladaptive changes in the processing of sensory input by the central nervous system are central to understanding chronic (back) pain. Nonpainful, posterior-anterior (PA) movement pressure was applied manually to lumbar vertebrae at L1, L3, and L5 in 13 healthy subjects and 13 CLBP patients. The manual pressure (30 N) was monitored and controlled using sensors. A randomized stimulation protocol was used consisting of 51 pressure stimuli of 5 seconds duration. fMRI data analysis was performed for the group activation within the primary and secondary sensory cortices (S1 and S2, respectively) and the representation of the individual vertebrae was extracted and statistically analyzed. Nonpainful PA pressure revealed no cortical reorganization in S1. In contrast, the extent of S2 activation in the CLBP group was significantly reduced in both hemispheres. In the control group, a somatotopy was identified for the lumbar vertebrae between L1 and L3, respectively, and L5 in S2 of the right hemisphere. Most importantly, a blurring of the somatotopic representation of the lumbar spine in S2 was observed in the patient group. Together, these maladaptive changes suggest a reorganization of higher-order processing for sensory information in CLBP patients that might have implications for a decreased sensory acuity, also related to body perception and subsequent altered functioning of the lumbar spine. 2.

Development and Validation of the Behavioral Avoidance Test-Back Pain (BAT-Back) for Patients With Chronic Low Back Pain.

Science.gov (United States)

Holzapfel, Sebastian; Riecke, Jenny; Rief, Winfried; Schneider, Jessica; Glombiewski, Julia A

2016-11-01

Pain-related fear and avoidance of physical activities are central elements of the fear-avoidance model of musculoskeletal pain. Pain-related fear has typically been measured by self-report instruments. In this study, we developed and validated a Behavioral Avoidance Test (BAT) for chronic low back pain (CLBP) patients with the aim of assessing pain-related avoidance behavior by direct observation. The BAT-Back was administered to a group of CLBP patients (N=97) and pain-free controls (N=31). Furthermore, pain, pain-related fear, disability, catastrophizing, and avoidance behavior were measured using self-report instruments. Reliability was assessed with intraclass correlation coefficient and Cronbach α. Validity was assessed by examining correlation and regression analysis. The intraclass correlation coefficient for the BAT-Back avoidance score was r=0.76. Internal consistency was α=0.95. CLBP patients and controls differed significantly on BAT-Back avoidance scores as well as self-report measures. BAT-Back avoidance scores were significantly correlated with scores on each of the self-report measures (rs=0.27 to 0.54). They were not significantly correlated with general anxiety and depression, age, body mass index, and pain duration. The BAT-Back avoidance score was able to capture unique variance in disability after controlling for other variables (eg, pain intensity and pain-related fear). Results indicate that the BAT-Back is a reliable and valid measure of pain-related avoidance behavior. It may be useful for clinicians in tailoring treatments for chronic pain as well as an outcome measure for exposure treatments.

Tactical mediatization and activist ageing: pressures, push-backs, and the story of RECAA

Directory of Open Access Journals (Sweden)

Kim Sawchuk

2013-03-01

Full Text Available This case study examines the incorporation of digital media technologies and practices into Respecting Elders: Communities Against elder Abuse (RECAA, an organization of activist elders. By studying RECAA’s specific transition and following the work of Michel de Certeau (1988, I distinguish between tactical mediatization and strategic mediatization. Organizations such as RECAA must negotiate with political, ideological, administrative, and economic agendas that exert pressure and provide incentives for organizations “to mediatize” in order to survive in the current Canadian context. ‘Tactical mediatization’ is used to understand RECAA’s very deliberate and considered response to these pressures. This distinction provides a framework for conceptualizing how activist organizations such as RECAA struggle to exert agency within meta-processes that place mounting and insistent pressure on the organization to incorporate digital media technologies into its mandate and system of values.

Experimental Pressure-Volume diagrams of scroll compressors

OpenAIRE

Picavet, Alain; Ginies, Pierre

2014-01-01

This paper presents the results of tests led with scroll compressors to establish pressure-volume diagrams. Two compressors were thinly instrumented with pressure and displacement sensors so as to follow the whole compression process, from suction to exhaust. A gear coder was set to mark off the closing and opening of gas pockets, and to study the speed variations occurring during a single rotation. These tests help to understand the various phenomena met in a compressor, such as back-flow, o...

The effects of Transcutaneous Electrical Nerve Stimulation on postural control in patients with chronic low back pain

OpenAIRE

Rojhani-Shirazi, Z; Rezaeian, T

2015-01-01

Objective: The effects of transcutaneous electrical nerve stimulation (TENS) on postural control in patients with low back pain which is not well known. This study aimed to evaluate the effects of TENS on postural control in chronic low back pain. Methods: This study was an experimental research design. Twenty-eight patients with chronic LBP (25-45 Y/ O) participated and by using a random allocation, were divided to samples who participated in this study. The mean center of pressure (COP) vel...

The development and exploratory analysis of the Back Pain Attitudes Questionnaire (Back-PAQ).

Science.gov (United States)

Darlow, Ben; Perry, Meredith; Mathieson, Fiona; Stanley, James; Melloh, Markus; Marsh, Reginald; Baxter, G David; Dowell, Anthony

2014-05-23

To develop an instrument to assess attitudes and underlying beliefs about back pain, and subsequently investigate its internal consistency and underlying structures. The instrument was developed by a multidisciplinary team of clinicians and researchers based on analysis of qualitative interviews with people experiencing acute and chronic back pain. Exploratory analysis was conducted using data from a population-based cross-sectional survey. Qualitative interviews with community-based participants and subsequent postal survey. Instrument development informed by interviews with 12 participants with acute back pain and 11 participants with chronic back pain. Data for exploratory analysis collected from New Zealand residents and citizens aged 18 years and above. 1000 participants were randomly selected from the New Zealand Electoral Roll. 602 valid responses were received. The 34-item Back Pain Attitudes Questionnaire (Back-PAQ) was developed. Internal consistency was evaluated by the Cronbach α coefficient. Exploratory analysis investigated the structure of the data using Principal Component Analysis. The 34-item long form of the scale had acceptable internal consistency (α=0.70; 95% CI 0.66 to 0.73). Exploratory analysis identified five two-item principal components which accounted for 74% of the variance in the reduced data set: 'vulnerability of the back'; 'relationship between back pain and injury'; 'activity participation while experiencing back pain'; 'prognosis of back pain' and 'psychological influences on recovery'. Internal consistency was acceptable for the reduced 10-item scale (α=0.61; 95% CI 0.56 to 0.66) and the identified components (α between 0.50 and 0.78). The 34-item long form of the scale may be appropriate for use in future cross-sectional studies. The 10-item short form may be appropriate for use as a screening tool, or an outcome assessment instrument. Further testing of the 10-item Back-PAQ's construct validity, reliability

Back Pain in Children

Directory of Open Access Journals (Sweden)

Sadi Kayiran ; Sinan Mahir Kayiran;

2011-02-01

Full Text Available Contrary to popular knowledge, back pain is quite frequently seen in children. While very rare in the pre-school age group, frequency reaches 30% in the adolescent period. In many cases, the causes of back pain in childhood cannot be exactly determined and the pain disappears by itself in a short time. It should be remembered that back pain that persists for more than two weeks may be associated with organic causes. Whether or not there have been disruptions in neurological functions should be definitely probed in the medical history. Keeping in mind that back pain could be a part of a systemic disease, a systemic examination should be carried out in cases where there has been long-term back pain. The complaint of childhood back pain should be assessed with a thorough history, a careful physical examination and advanced testing tools. [TAF Prev Med Bull 2011; 10(1.000: 115-118

Intentional back flow effects on ruptured steam generator cooldown during a SGTR event for KSNP

International Nuclear Information System (INIS)

Seok, Jeong Park; Cheol, Woo Kim; Chul, Jin Choi; Jong, Tae Seo

2001-01-01

For an optimum recovery from a Steam Generator Tube Rupture (SGTR) event, the operators are directed to isolate the steam generator (SG) with ruptured tube(s) as early as possible in order to minimize the radioactive material release. However, the Reactor Coolant System (RCS) cooldown and depressurization to the Residual Heat Removal (RHR) System operation conditions using the intact SG only can not be readily achievable unless the affected SG is properly cooled since the isolated SG remains at high temperature even though the RCS has been cooled down. Therefore, a study on the intentional back flow from the ruptured SG secondary side to the RCS was performed to evaluate its effectiveness on the ruptured SG cooldown during a SGTR event for the pressurized light water reactor, especially for the Korean Standard Nuclear Power Plant (KSNP). In order to evaluate the intentional back flow effect, a series of analyses was conducted by using RELAP5/MOD3 computer code. In these analyses, the primary and secondary systems of KSNP are modeled including the major Nuclear Steam Supply System (NSSS) components such as the reactor vessel, steam generators, hot and cold legs, pressurizer, and reactor coolant pumps. Also, the key safety systems and control systems are modeled. Using this model, two possible methods of the ruptured SG cooldown by using back flow after RCS cooldown were evaluated: the first method is a tube uncover method, and the second method is a SG drain (back flow) and fill method. (author)

People with low back pain perceive needs for non-biomedical services in workplace, financial, social and household domains: a systematic review

Directory of Open Access Journals (Sweden)

Louisa Chou

2018-04-01

Full Text Available Question: What needs of non-biomedical services are perceived by people with low back pain? Design: Systematic review of qualitative and quantitative studies examining perceived needs of non-biomedical services for low back pain, identified through searching of MEDLINE, EMBASE, CINAHL and PsycINFO (1990 to 2016. Participants: Adults with low back pain of any duration. Data extraction and analysis: Descriptive data regarding study design and methodology were extracted. The preferences, expectations and satisfaction with non-biomedical services reported by people with low back pain were identified and categorised within areas of perceived need. Results: Twenty studies (19 qualitative and one quantitative involving 522 unique participants (total pool of 590 were included in this systematic review. Four areas emerged. Workplace: people with low back pain experience pressure to return to work despite difficulties with the demands of their occupation. They want their employers to be informed about low back pain and they desire workplace accommodations. Financial: people with low back pain want financial support, but have concerns about the inefficiencies of compensation systems and the stigma associated with financial remuneration. Social: people with low back pain report feeling disconnected from social networks and want back-specific social support. Household: people with low back pain report difficulties with household duties; however, there are few data regarding their need for auxiliary devices and domestic help. Conclusion: People with low back pain identified work place, financial and social pressures, and difficulties with household duties as areas of need beyond their healthcare requirements that affect their ability to comply with management of their condition. Consideration of such needs may inform physiotherapists, the wider health system, social networks and the workplace to provide more relevant and effective services. [Chou L, Cicuttini

Conditioned pain modulation in patients with nonspecific chronic back pain with chronic local pain, chronic widespread pain, and fibromyalgia.

Science.gov (United States)

Gerhardt, Andreas; Eich, Wolfgang; Treede, Rolf-Detlef; Tesarz, Jonas

2017-03-01

Findings considering conditioned pain modulation (CPM) in chronic back pain (CBP) are contradictory. This might be because many patients with CBP report pain in further areas of the body, and altered CPM might influence spatial extent of pain rather than CBP per se. Therefore, we compared CPM in patients with CBP with different pain extent. Patients with fibromyalgia syndrome (FMS), for whom CPM impairment is reported most consistently, were measured for comparison. Based on clinical evaluation and pain drawings, patients were categorized into chronic local back pain (CLP; n = 53), chronic widespread back pain (CWP; n = 32), and FMS (n = 92). Conditioned pain modulation was measured by the difference in pressure pain threshold (test stimuli) at the lower back before and after tonic heat pain (conditioning stimulus). We also measured psychosocial variables. Pressure pain threshold was significantly increased in CLP patients after tonic heat pain (P pain modulation in CLP was significantly higher than that in CWP and FMS (P painful areas (0-10) were associated with lower CPM (r = 0.346, P = 0.001) in CBP but not in FMS (r = -0.013, P = 0.903). Anxiety and depression were more pronounced in FMS than in CLP or CWP (P values pain inhibition seem to be more indicated the higher the pain extent.

Pressing back: Split Britches' Lost Lounge and the retro performativity of lesbian performance.

Science.gov (United States)

Eschen, Nicole

2013-01-01

Using theories of affect and queer temporality, this article examines Split Britches' Lost Lounge as lesbian resistance to the pressures to remember or forget the past, condemn or embrace the future. In this piece, butch-femme duo Peggy Shaw and Lois Weaver develop a retro performativity that pushes back against systems that strive to make lesbianism invisible, private, and apolitical. Through performances that resignify past pop culture artifacts, particularly the duo of Louis Prima and Keely Smith, Shaw and Weaver perform a past that is simultaneously lost and embodied, pressuring the audience to reconsider notions of progress and beauty.

Low back pain

DEFF Research Database (Denmark)

Buchbinder, Rachelle; van Tulder, Maurits; Öberg, Birgitta

2018-01-01

Low back pain is the leading worldwide cause of years lost to disability and its burden is growing alongside the increasing and ageing population.1 Because these population shifts are more rapid in low-income and middle-income countries, where adequate resources to address the problem might...... not exist, the effects will probably be more extreme in these regions. Most low back pain is unrelated to specific identifiable spinal abnormalities, and our Viewpoint, the third paper in this Lancet Series,2,3 is a call for action on this global problem of low back pain....

Germination of vegetable seeds exposed to very high pressure

International Nuclear Information System (INIS)

Mori, Y; Yokota, S; Ono, F

2012-01-01

Effects of high hydrostatic pressure were investigated on vegetable seeds in the GPa range to examine the potentialities of breed improvement by high-pressure processing. Specimens of several seeds of broccoli (Brassica oleracea var. italica), Turnip leaf (Brassica rapa var. perviridis) and Potherb Mustard (Brassica rapa var. nipposinica) were put in a teflon capsule with liquid high pressure medium, fluorinate, and inserted into a pyrophillite cube. By using a cubic anvil press a hydrostatic pressure of 5.5 GP a was applied to these seeds for 15 minutes. After being brought back to ambient pressure, they were seeded on humid soil in a plant pot. Many of these vegetable seeds began to germinate within 6 days after seeded.

Germination of vegetable seeds exposed to very high pressure

Science.gov (United States)

Mori, Y.; Yokota, S.; Ono, F.

2012-07-01

Effects of high hydrostatic pressure were investigated on vegetable seeds in the GPa range to examine the potentialities of breed improvement by high-pressure processing. Specimens of several seeds of broccoli (Brassica oleracea var. italica), Turnip leaf (Brassica rapa var. perviridis) and Potherb Mustard (Brassica rapa var. nipposinica) were put in a teflon capsule with liquid high pressure medium, fluorinate, and inserted into a pyrophillite cube. By using a cubic anvil press a hydrostatic pressure of 5.5 GP a was applied to these seeds for 15 minutes. After being brought back to ambient pressure, they were seeded on humid soil in a plant pot. Many of these vegetable seeds began to germinate within 6 days after seeded.

Marjolin's Ulcer Complicating a Pressure Sore: The Clock is Ticking.

Science.gov (United States)

Khan, Kamran; Giannone, Anna Lucia; Mehrabi, Erfan; Khan, Ayda; Giannone, Roberto E

2016-02-22

Malignant degeneration in any chronic wound is termed a Marjolin's ulcer (MU). The overall metastatic rate of MU is approximately 27.5%. However, the prognosis of MU specific to pressure sores is poor, with a reported metastatic rate of 61%. This is due to insidious, asymptomatic malignant degeneration, a lack of healthcare provider awareness, and, ultimately, delayed management. An 85-year-old white male was noted by his wound-care nurse to have a rapidly developing growth on his lower back over a period of 4 months. There was history of a non-healing, progressive pressure ulcer of the lower back for the past 10 years. On examination, there was a 4 × 4 cm pressure ulcer of the lower back, with a superimposed 1.5 × 2 cm growth in the superior region. There was an absence of palpable regional lymphadenopathy. Punch biopsy revealed squamous cell carcinoma consistent with Marjolin's ulcer. The ulcer underwent excision with wide margins, and a skin graft was placed. Due to the prompt recognition of an abnormality by the patient's wound-care nurse, metastasis was not evident on imaging. There are no signs of recurrence at 1-year follow-up. Marjolin's ulcer has a rapid progression from local disease to widespread metastasis. Therefore, it is essential that wound-care providers are aware of the clinical signs and symptoms of malignant degeneration in chronic wounds.

Accurate prediction of retention in hydrophilic interaction chromatography by back calculation of high pressure liquid chromatography gradient profiles.

Science.gov (United States)

Wang, Nu; Boswell, Paul G

2017-10-20

Gradient retention times are difficult to project from the underlying retention factor (k) vs. solvent composition (φ) relationships. A major reason for this difficulty is that gradients produced by HPLC pumps are imperfect - gradient delay, gradient dispersion, and solvent mis-proportioning are all difficult to account for in calculations. However, we recently showed that a gradient "back-calculation" methodology can measure these imperfections and take them into account. In RPLC, when the back-calculation methodology was used, error in projected gradient retention times is as low as could be expected based on repeatability in the k vs. φ relationships. HILIC, however, presents a new challenge: the selectivity of HILIC columns drift strongly over time. Retention is repeatable in short time, but selectivity frequently drifts over the course of weeks. In this study, we set out to understand if the issue of selectivity drift can be avoid by doing our experiments quickly, and if there any other factors that make it difficult to predict gradient retention times from isocratic k vs. φ relationships when gradient imperfections are taken into account with the back-calculation methodology. While in past reports, the accuracy of retention projections was >5%, the back-calculation methodology brought our error down to ∼1%. This result was 6-43 times more accurate than projections made using ideal gradients and 3-5 times more accurate than the same retention projections made using offset gradients (i.e., gradients that only took gradient delay into account). Still, the error remained higher in our HILIC projections than in RPLC. Based on the shape of the back-calculated gradients, we suspect the higher error is a result of prominent gradient distortion caused by strong, preferential water uptake from the mobile phase into the stationary phase during the gradient - a factor our model did not properly take into account. It appears that, at least with the stationary phase

Effects of the imposed pressure differential conditions on duoplasmatron performance

International Nuclear Information System (INIS)

Oztarhan, A.

1988-01-01

The duoplasmatron plasma source (D.P.T.) was modified to allow access to the arc discharge (to measure the discharge properties) and to vary independently the pressures in different volumes of the arc with the aim of seeing if this freedom would help in optimising the output. The duoplasmatron plasma source was operated under normal running condition (N.R.C.), positive imposed pressure differential condition (P.I.P.D.C.) and negative imposed pressure differential condition (N.I.P.D.C.) and the corresponding properties of the plasma output were measured. Running the duoplasmatron under P.I.P.D. condition did not seem to improve the output as compared to that under N.R.C. However, running the duoplasmatron under N.I.P.D. condition seemed to be advantageous as the output increased by about 30%. It was observed that the back pressure was critical in maintaining the arc and the gap pressure could be lowered much below the normal minimum (while the arc was on) if back pressure was kept above a critical value. The results showed that the effects of varying the dimensions of the intermediate electrode nozzle on the output could be understood in terms of the effect of changes in these dimensions on the relative pressures. An empirical expression for the effect of the pressure ratio was developed from the observations and compared with the experimental results. The reasons for various results can be related to the plasma emission mechanism. (author). 8 refs, 6 figs, 1 tab

Dynamic High Pressure Study of Chemistry and Physics of Molecular Materials

Science.gov (United States)

Jezowski, Sebastian Ryszard

Both temperature and pressure control and influence the packing of molecules in crystalline phases. Our molecular simulations indicate that at ambient pressure, the cubic polymorph of tetracyanoethylene, TCNE, is the energetically stable form up to ˜ 160 K. The observed transition from the cubic to the monoclinic polymorph occurs however only at temperatures above ˜ 318 K due to the large transition barrier. The temperature-induced phase transition in TCNE studied with high-resolution IR spectroscopy is explained in terms of the increased vibrational entropy in the crystals of the monoclinic polymorph. Based upon the inverted design of the Merril-Bassett Diamond Anvil Cell, an improved, second generation dynamic Diamond Anvil Cell was developed. Based on the fluorescence of ruby crystals, we were able to demonstrate that the pressure variation range can be further increased at least up to 7 kbar and that the dynamic pressure compression of up to 1400 GPa/s can be achieved. A new class of mechanophoric system, bis-anthracene, BA, and its photoisomer, PI, is shown to respond reversibly to a mild, static pressure induced by a Diamond Anvil Cell as well as to shear deformation based on absorption spectroscopic measurements. The forward reaction occurs upon illumination with light while the back-reaction may be accelerated upon heating or mechanical stress, coupled to a rehybridization on four equivalent carbon atoms. It is an intriguing result as high pressure stabilizes the photodimerized species in related systems. Our molecular volume simulations ruled out significant differences in the volumes between bis-anthracene and its photoisomer. Kinetic absorption measurements at several different pressures reveal a negative volume of activation in the exothermic back-reaction at room temperature. Through a series of temperature-dependent kinetic measurements it is shown that the barrier of activation for the back-reaction is reduced by more than an order of magnitude at

A Review on Pressure Ulcer: Aetiology, Cost, Detection and Prevention Systems

OpenAIRE

Mishu, Mahbub C.; Dubey, Venketesh N.; Hickish, Tamas F.; Cole, Jonathan

2014-01-01

Pressure ulcer (also known as pressure sore, bedsore, ischemia, decubitus ulcer) is a global challenge for today’s healthcare society. Found in several locations in the human body such as the sacrum, heel, back of the head, shoulder, knee caps, it occurs when soft tissues are under continuous loading and a subject’s mobility is restricted (bedbound/chair bound). Blood flow in soft tissues becomes insufficient leading to tissue necrosis (cell death) and pressure ulcer. The subject’s physiologi...

The effect of shaped wheelchair cushion and lumbar supports on under-seat pressure, comfort, and pelvic rotation.

Science.gov (United States)

Samuelsson, Kersti; Björk, Maarit; Erdugan, Ann-Marie; Hansson, Anna-Karin; Rustner, Birgitta

2009-09-01

A wheelchair seat and position help clients perform daily activities. The comfort of the wheelchair can encourage clients to participate in daily activities and can help prevent future complications. This study evaluates how a shaped seat-cushion and two different back supports affect under-seat pressure, comfort, and pelvic rotation. Thirty healthy subjects were tested using two differently equipped manual wheelchairs. One wheelchair had a Velcro adjustable back seat and a plane seat-cushion. The other wheelchair had a non-adjustable sling-back seat and a plane cushion. The second wheelchair was also equipped with a shaped cushion and/or a detachable lumbar support. Under-seat pressure, estimated comfort, and pelvic rotation were measured after 10 min in each wheelchair outfit. Peak pressure increased with the shaped cushion compared to the plane cushion. No significant difference in estimated comfort was found. Pelvic posterior-rotation was reduced with the adjustable or detachable back-support irrespective of the shape of the seat cushion. To support a neutral pelvic position and spinal curvature, a combination of a shaped cushion and a marked lumbar support is most effective.

Power flow controller with a fractionally rated back-to-back converter

Science.gov (United States)

Divan, Deepakraj M.; Kandula, Rajendra Prasad; Prasai, Anish

2016-03-08

A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.

Fall Back Equilibrium

NARCIS (Netherlands)

Kleppe, J.; Borm, P.E.M.; Hendrickx, R.L.P.

2008-01-01

Fall back equilibrium is a refinement of the Nash equilibrium concept. In the underly- ing thought experiment each player faces the possibility that, after all players decided on their action, his chosen action turns out to be blocked. Therefore, each player has to decide beforehand on a back-up

Navigating Earthquake Physics with High-Resolution Array Back-Projection

Science.gov (United States)

Meng, Lingsen

Understanding earthquake source dynamics is a fundamental goal of geophysics. Progress toward this goal has been slow due to the gap between state-of-art earthquake simulations and the limited source imaging techniques based on conventional low-frequency finite fault inversions. Seismic array processing is an alternative source imaging technique that employs the higher frequency content of the earthquakes and provides finer detail of the source process with few prior assumptions. While the back-projection provides key observations of previous large earthquakes, the standard beamforming back-projection suffers from low resolution and severe artifacts. This thesis introduces the MUSIC technique, a high-resolution array processing method that aims to narrow the gap between the seismic observations and earthquake simulations. The MUSIC is a high-resolution method taking advantage of the higher order signal statistics. The method has not been widely used in seismology yet because of the nonstationary and incoherent nature of the seismic signal. We adapt MUSIC to transient seismic signal by incorporating the Multitaper cross-spectrum estimates. We also adopt a "reference window" strategy that mitigates the "swimming artifact," a systematic drift effect in back projection. The improved MUSIC back projections allow the imaging of recent large earthquakes in finer details which give rise to new perspectives on dynamic simulations. In the 2011 Tohoku-Oki earthquake, we observe frequency-dependent rupture behaviors which relate to the material variation along the dip of the subduction interface. In the 2012 off-Sumatra earthquake, we image the complicated ruptures involving orthogonal fault system and an usual branching direction. This result along with our complementary dynamic simulations probes the pressure-insensitive strength of the deep oceanic lithosphere. In another example, back projection is applied to the 2010 M7 Haiti earthquake recorded at regional distance. The

Tweeting back: predicting new cases of back pain with mass social media data.

Science.gov (United States)

Lee, Hopin; McAuley, James H; Hübscher, Markus; Allen, Heidi G; Kamper, Steven J; Moseley, G Lorimer

2016-05-01

Back pain is a global health problem. Recent research has shown that risk factors that are proximal to the onset of back pain might be important targets for preventive interventions. Rapid communication through social media might be useful for delivering timely interventions that target proximal risk factors. Identifying individuals who are likely to discuss back pain on Twitter could provide useful information to guide online interventions. We used a case-crossover study design for a sample of 742 028 tweets about back pain to quantify the risks associated with a new tweet about back pain. The odds of tweeting about back pain just after tweeting about selected physical, psychological, and general health factors were 1.83 (95% confidence interval [CI], 1.80-1.85), 1.85 (95% CI: 1.83-1.88), and 1.29 (95% CI, 1.27-1.30), respectively. These findings give directions for future research that could use social media for innovative public health interventions. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Overtreating chronic back pain: time to back off?

Science.gov (United States)

Deyo, Richard A; Mirza, Sohail K; Turner, Judith A; Martin, Brook I

2009-01-01

Chronic back pain is among the most common patient complaints. Its prevalence and impact have spawned a rapidly expanding range of tests and treatments. Some of these have become widely used for indications that are not well validated, leading to uncertainty about efficacy and safety, increasing complication rates, and marketing abuses. Recent studies document a 629% increase in Medicare expenditures for epidural steroid injections; a 423% increase in expenditures for opioids for back pain; a 307% increase in the number of lumbar magnetic resonance images among Medicare beneficiaries; and a 220% increase in spinal fusion surgery rates. The limited studies available suggest that these increases have not been accompanied by population-level improvements in patient outcomes or disability rates. We suggest a need for a better understanding of the basic science of pain mechanisms, more rigorous and independent trials of many treatments, a stronger regulatory stance toward approval and post-marketing surveillance of new drugs and devices for chronic pain, and a chronic disease model for managing chronic back pain.

Analysis of lower back pain disorder using deep learning

Science.gov (United States)

Ritwik Kulkarni, K.; Gaonkar, Abhijitsingh; Vijayarajan, V.; Manikandan, K.

2017-11-01

Lower back pain (LBP) is caused because of assorted reasons involving body parts such as the interconnected network of spinal cord, nerves, bones, discs or tendons in the lumbar spine. LBP is pain, muscle pressure, or stiffness localized underneath the costal edge or more the substandard gluteal folds, with or without leg torment for the most part sciatica, and is characterized as endless when it holds on for 12 weeks or more then again, non-particular LBP is torment not credited to an unmistakable pathology such as infection, tumour, osteoporosis, rheumatoid arthritis, fracture, or inflammation. Over 70% of people usually suffer from such backpain disorder at some time. But recovery is not always favorable, 82% of non-recent-onset patients still experience pain 1 year later. Even though not having any history of lower back pain, many patients suffering from this disorder spend months or years healing from it. Hence aiming to look for preventive measure rather than curative, this study suggests a classification methodology for Chronic LBP disorder using Deep Learning techniques.

Sources and mitigation of interharmonics in back-to-back controllable drives

DEFF Research Database (Denmark)

Soltani, Hamid; Loh, Poh Chiang; Blaabjerg, Frede

2014-01-01

for the sources, leading to undistorted grid currents, which are growingly important as more drives are tied to the grid. It is shown that in the case of back-to-back controllable drives it is possible to reduce the input current interharmonic distortion caused by motor current imbalance....

Trajectories of low back pain

DEFF Research Database (Denmark)

Axén, Iben; Leboeuf-Yde, Charlotte

2013-01-01

Low back pain is not a self-limiting problem, but rather a recurrent and sometimes persistent disorder. To understand the course over time, detailed investigation, preferably using repeated measurements over extended periods of time, is needed. New knowledge concerning short-term trajectories...... indicates that the low back pain 'episode' is short lived, at least in the primary care setting, with most patients improving. Nevertheless, in the long term, low back pain often runs a persistent course with around two-thirds of patients estimated to be in pain after 12 months. Some individuals never have...... low back pain, but most have it on and off or persistently. Thus, the low back pain 'condition' is usually a lifelong experience. However, subgroups of patients with different back pain trajectories have been identified and linked to clinical parameters. Further investigation is warranted...

Pressure heat pumping in the orifice pulse-tube refrigerator

International Nuclear Information System (INIS)

Boer, P.C.T. de

1996-01-01

The mechanism by which heat is pumped as a result of pressure changes in an orifice pulse-tube refrigerator (OPTR) is analyzed thermodynamically. The thermodynamic cycle considered consists of four steps: (1) the pressure is increased by a factor π 1 due to motion of a piston in the heat exchanger at the warm end of the regenerator; (2) the pressure is decreased by a factor π 2 due to leakage out of the orifice; (3) the pressure is further decreased due to motion of the piston back to its original position; (4) the pressure is increased to its value at the start of the cycle due to leakage through the orifice back into the pulse tube. The regenerator and the heat exchangers are taken to be perfect. The pressure is assumed to be uniform during the entire cycle. The temperature profiles of the gas in the pulse tube after each step are derived analytically. Knowledge of the temperature at which gas enters the cold heat exchanger during steps 3 and 4 provides the heat removed per cycle from this exchanger. Knowledge of the pressure as a function of piston position provides the work done per cycle by the piston. The pressure heat pumping mechanism considered is effective only in the presence of a regenerator. Detailed results are presented for the heat removed per cycle, for the coefficient of performance, and for the refrigeration efficiency as a function of the compression ratio π 1 and the expansion ratio π 2 . Results are also given for the influence on performance of the ratio of specific heats. The results obtained are compared with corresponding results for the basic pulse-tube refrigerator (BPTR) operating by surface heat pumping

When Your Back Hurts: Don't Let Back Pain Knock You Flat

Science.gov (United States)

... Your Back Hurts Don’t Let Back Pain Knock You Flat En español Send us your comments ... Complementary Health Approaches Halt the Hurt! References The SPORT Value Compass: Do the Extra Costs of Undergoing ...

Numerical analysis of the flow field in the pump chamber of a centrifugal pump with back blades

International Nuclear Information System (INIS)

Cao, L; Wang, Z W; Luo, Y Y; Liu, M

2013-01-01

Black blade is frequently used as a non-contact seal structure in centrifugal pumps transporting solid-liquid two-phase flow. However, it will disturb the flow in the pump and affect the pump performance. Numerical simulation for 3D turbulence in whole flow passage of a centrifugal pump with back blades was carried out based on RANS method, with SST k-ω turbulence model and SIMPLEC algorithm. Calculation for a similar pump without back blades was also carried out as a comparison. Boundary condition was improved due to the existence of back blade. The influence of back blades on the flow field was analysed qualitatively for three typical conditions. Meanwhile the leakage rate was calculated for several conditions and the effect of back blades was discussed. According to the results, compared with the condition without back blades, it could be seen that back blade apparently changed the flow state in the front chamber, improved near the front shroud and worsened near the pump cover. Velocity was increased and more fluid, which flowed into the front chamber from the pump cover side, flowed back to the spiral casing from the impeller shroud side. With the increase of discharge, the absolute value of leakage rate first went up and then dropped, as a consequence of the combination of two factors, discharge and differential pressure between the impeller outlet and inlet. The seal effect of back blades is most obvious under small discharge condition, and the leakage loss diminished as discharge increased

A new fabrication technique for back-to-back varactor diodes

Science.gov (United States)

Smith, R. Peter; Choudhury, Debabani; Martin, Suzanne; Frerking, Margaret A.; Liu, John K.; Grunthaner, Frank A.

1992-01-01

A new varactor diode process has been developed in which much of the processing is done from the back of an extremely thin semiconductor wafer laminated to a low-dielectric substrate. Back-to-back BNN diodes were fabricated with this technique; excellent DC and low-frequency capacitance measurements were obtained. Advantages of the new technique relative to other techniques include greatly reduced frontside wafer damage from exposure to process chemicals, improved capability to integrate devices (e.g. for antenna patterns, transmission lines, or wafer-scale grids), and higher line yield. BNN diodes fabricated with this technique exhibit approximately the expected capacitance-voltage characteristics while showing leakage currents under 10 mA at voltages three times that needed to deplete the varactor. This leakage is many orders of magnitude better than comparable Schottky diodes.

Push-Back Leadership.

Science.gov (United States)

Tetenbaum, Toby J.; Tetenbaum, Hilary

2003-01-01

Describes push-back leadership, a model of leadership based on the work of Ronald Heifetz and Martin Linksky. Argues that the two key roles of the leader are to give the work back to people and to keep them within a healthy range of disequilibrium that generates creativity and innovation to solve organizational problems. (Author/LRW)

Postural balance in low back pain patients

DEFF Research Database (Denmark)

Maribo, Thomas; Schiøttz-Christensen, Berit; Jensen, Lone Donbæk

2012-01-01

INTRODUCTION: Altered postural control has been observed in low back pain (LBP) patients. They seem to be more dependent on vision when standing. The objective of the study was to determine concurrent and predictive validity of measures of postural stability in LBP patients. MATERIALS AND METHODS......: Centre of Pressure (CoP) measurements were tested against pain, fear of pain, and physical function. Velocity, anterior-posterior displacement, and the Romberg Ratio obtained on a portable force platform were used as measures of postural stability. RESULTS: Baseline and 12-week follow-up results of 97....... CONCLUSION: This first study of concurrent and predictive validity of postural balance in LBP patients revealed no association between CoP measures and pain, fear of pain, and physical function....

Review on pressure swirl injector in liquid rocket engine

Science.gov (United States)

Kang, Zhongtao; Wang, Zhen-guo; Li, Qinglian; Cheng, Peng

2018-04-01

The pressure swirl injector with tangential inlet ports is widely used in liquid rocket engine. Commonly, this type of pressure swirl injector consists of tangential inlet ports, a swirl chamber, a converging spin chamber, and a discharge orifice. The atomization of the liquid propellants includes the formation of liquid film, primary breakup and secondary atomization. And the back pressure and temperature in the combustion chamber could have great influence on the atomization of the injector. What's more, when the combustion instability occurs, the pressure oscillation could further affects the atomization process. This paper reviewed the primary atomization and the performance of the pressure swirl injector, which include the formation of the conical liquid film, the breakup and atomization characteristics of the conical liquid film, the effects of the rocket engine environment, and the response of the injector and atomization on the pressure oscillation.

Alternative Packaging for Back-Illuminated Imagers

Science.gov (United States)

Pain, Bedabrata

2009-01-01

An alternative scheme has been conceived for packaging of silicon-based back-illuminated, back-side-thinned complementary metal oxide/semiconductor (CMOS) and charge-coupled-device image-detector integrated circuits, including an associated fabrication process. This scheme and process are complementary to those described in "Making a Back-Illuminated Imager With Back-Side Connections" (NPO-42839), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), page 38. To avoid misunderstanding, it should be noted that in the terminology of imaging integrated circuits, "front side" or "back side" does not necessarily refer to the side that, during operation, faces toward or away from a source of light or other object to be imaged. Instead, "front side" signifies that side of a semiconductor substrate upon which the pixel pattern and the associated semiconductor devices and metal conductor lines are initially formed during fabrication, and "back side" signifies the opposite side. If the imager is of the type called "back-illuminated," then the back side is the one that faces an object to be imaged. Initially, a back-illuminated, back-side-thinned image-detector is fabricated with its back side bonded to a silicon handle wafer. At a subsequent stage of fabrication, the front side is bonded to a glass wafer (for mechanical support) and the silicon handle wafer is etched away to expose the back side. The frontside integrated circuitry includes metal input/output contact pads, which are rendered inaccessible by the bonding of the front side to the glass wafer. Hence, one of the main problems is to make the input/output contact pads accessible from the back side, which is ultimately to be the side accessible to the external world. The present combination of an alternative packaging scheme and associated fabrication process constitute a solution of the problem.

Low back pain - chronic

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/007422.htm Low back pain - chronic To use the sharing features on this page, please enable JavaScript. Low back pain refers to pain that you feel in your ...

Residual stress and its effect on the mechanical properties of Y-doped Mg alloy fabricated via back-pressure assisted equal channel angular pressing (ECAP-BP)

Energy Technology Data Exchange (ETDEWEB)

Shen, Jianghua, E-mail: j_shen@live.cn [Department of Mechanical Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223-0001 (United States); School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072 (China); Gärtnerová, Viera [Laboratory of Nanostructures and Nanomaterials, Institute of Physics of the ASCR, Na Slovance 2, CZ – 182 21, Prague 8 (Czech Republic); Kecskes, Laszlo J. [US Army Research Laboratory, Aberdeen Proving Ground, MD 21005-5069 (United States); Kondoh, Katsuyoshi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaragi, Osaka 567-0047 (Japan); Jäger, Aleš, E-mail: jager@fzu.cz [Laboratory of Nanostructures and Nanomaterials, Institute of Physics of the ASCR, Na Slovance 2, CZ – 182 21, Prague 8 (Czech Republic); Wei, Qiuming [Department of Mechanical Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223-0001 (United States)

2016-07-04

In this study, pure magnesium (Mg) and Mg-0.6 wt% yttrium (Y) binary alloy were fabricated via casting followed by room temperature equal channel angular pressing (ECAP) using an applied back pressure (BP). Microstructural examination after ECAP-BP revealed a fine-grained Mg-Y alloy with a high residual stress level, whereas, the pure Mg exhibited a well-recrystallized microstructure with uniform and equiaxed grains, but retaining very little residual stress. The Y atoms were present in the Mg matrix as solid solutes and acted as dislocation and grain boundary blockers, thus suppressing dynamic recovery and/or recrystallization during the ECAP process. The Mg-Y alloy had an average grain size of ~400 nm, approximately one order smaller than that of pure Mg. The combination of high residual stress and ultrafine grains of the Mg-Y alloy gave rise to a significant difference in its mechanical behavior from that of the pure Mg, under both quasi-static and dynamic compressive loading.

Imaging in mechanical back pain

DEFF Research Database (Denmark)

Hansen, Bjarke Brandt; Hansen, Philip; Carrino, John A

2016-01-01

Low back pain is common and relates to a variety of overlapping pathologies. Within the last few decades, almost every medical imaging modality has been applied in the evaluation of low back pain. Imaging of the spine has a high priority in the assessment of patients with low back pain, who seem ...

Facilitated pronociceptive pain mechanisms in radiating back pain compared with localized back pain

DEFF Research Database (Denmark)

Vaegter, Henrik Bjarke; Palsson, Thorvaldur Skuli; Graven-Nielsen, Thomas

2017-01-01

Facilitated pain mechanisms and impaired pain inhibition are often found in chronic pain patients. This study compared clinical pain profiles, pain sensitivity, as well as pro-nociceptive and anti-nociceptive mechanisms in patients with localized low back pain (n=18), localized neck pain (n=17......), low back and radiating leg pain (n=18), or neck and radiating arm pain (n=17). It was hypothesized that patients with radiating pain had facilitated pain mechanisms and impaired pain inhibition compared with localized pain patients. Cuff algometry was performed on the non-painful lower leg to assess...... threshold (HPT) at the non-painful hand were also assessed. Clinical pain intensity, psychological distress, and disability were assessed with questionnaires. TSP was increased in patients with radiating back pain compared with localized back pain (Ppain or localized low...

Cyclic Sciatica and Back Pain Responds to Treatment of Underlying Endometriosis: Case Illustration.

Science.gov (United States)

Uppal, Jaya; Sobotka, Stanislaw; Jenkins, Arthur L

2017-01-01

Multiple causes outside the spine can mimic spinal back pain. Endometriosis is an important gynecologic disorder, which commonly affects the lower region of the female pelvis and less frequently the spine and soft tissues. The lumbosacral trunk is vulnerable to pressure from any abdominal mass originating from the uterus and the ovaries. Therefore symptoms of endometriosis include severe reoccurring pain in the pelvic area as well as lower back and abdominal pain. We report on a 39-year-old gymnast with cyclic sciatica and back pain, whose initial presentation initially led to a spinal fusion at L4/5 and L5/S1, but that procedure did not change her symptoms. Her diagnosis of endometriosis was not made until 2 years after her spinal fusion. Ultimately, once diagnosed with endometriosis of the retroperitoneal spinal and neural elements, her back and leg pain responded completely to hormonal therapy and then to a hysterectomy and a bilateral salpingo-oophorectomy. Because her true diagnosis of endometriosis was unknown and she had some degenerative changes in her spine, she underwent a spinal fusion that would probably not have been done if the diagnosis of endometriosis had been suggested. It is critical for any clinician who deals with back pain to at least consider the diagnosis of endometriosis in female patients who have a history of pelvic pain. The diagnosis of endometriosis should be considered in candidate patients by asking whether there is a significant hormonal cyclic nature to the symptoms, to prevent such unnecessary surgical adventures. Copyright © 2016 Elsevier Inc. All rights reserved.

20 CFR 404.1242 - Back pay.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Back pay. 404.1242 Section 404.1242 Employees... Prior to 1987 § 404.1242 Back pay. (a) Back pay defined. Back pay is pay received in one period of time... an employer. It includes pay made under Federal or State laws intended to create an employment...

Excruciating Low Back Pain After Strenuous Exertion: Beware of Lumbar Paraspinal Compartment Syndrome.

Science.gov (United States)

Vanbrabant, Peter; Moke, Lieven; Meersseman, Wouter; Vanderschueren, Geert; Knockaert, Daniel

2015-11-01

Low back pain is extremely common and usually a minor self-limiting condition. Rarely, however, it is a harbinger of serious medical illness. Paraspinal compartment syndrome is a rare condition, but its timely recognition is important to allow adequate treatment. A 16-year-old boy presented to the Emergency Department (ED) with severe low back pain, necessitating intravenous opioids. Laboratory results showed severe rhabdomyolysis. Magnetic resonance imaging of the lumbar spine showed diffuse edema and swelling in the paraspinal muscles. Aggressive fluid therapy was started but despite narcotic analgesia the pain persisted and creatine kinase (CK) levels increased. Compartment pressures of the erector spinae were found to be increased. The decision was made to proceed with bilateral paraspinal fasciotomies. Postoperatively, the patient noted immediate pain relief with rapid decrease of CK level. The patient is pain free and resumed running and swimming 3 months after admission in the ED. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although paraspinal compartment syndrome is a rare condition, its recognition is of paramount importance to allow adequate surgical treatment, preventing muscle necrosis. Although back pain most often has a benign course, a careful history and physical examination in patients presenting with low back pain allows determination of "red flags." Mandatory further diagnostic tests can identify underlying serious illness. Copyright © 2015 Elsevier Inc. All rights reserved.

Looking back at 'looking back': operationalising referential gaze for dingoes in an unsolvable task.

Science.gov (United States)

Smith, Bradley Philip; Litchfield, Carla Anita

2013-11-01

This paper examined the performance of dingoes (Canis dingo) on the rope-pulling task, previously used by Miklósi et al. (Curr Biol 13:763-766, 2003) to highlight a key distinction in the problem-solving behaviour of wolves compared to dogs when in the company of humans. That is, when dogs were confronted with an unsolvable task, following a solvable version of the task they looked back or gazed at the human, whereas, wolves did not. We replicated the rope-pulling task using 12 sanctuary-housed dingoes and used the Miklósi et al. (Curr Biol 13:763-766, 2003) definition of looking back behaviour to analyse the data. However, at least three different types of look backs were observed in our study. We, then developed a more accurate operational definition of looking back behaviour that was task specific and reanalysed the data. We found that the operational definition employed greatly influences the results, with vague definitions potentially overestimating the prevalence of looking back behaviour. Thus, caution must be taken when interpreting the results of studies utilising looking back as behaviour linked to assistance seeking during problem solving. We present a more stringent definition and make suggestions for future research.

Pressure breathing in fighter aircraft for G accelerations and loss of cabin pressurization at altitude--a brief review.

Science.gov (United States)

Lauritzsen, Lars P; Pfitzner, John

2003-04-01

The purpose of this brief review is to outline the past and present use of pressure breathing, not by patients but by fighter pilots. Of the historical and recent references quoted, most are from aviation-medicine journals that are not often readily available to anesthesiologists. Pressure breathing at moderate levels of airway pressure gave World War II fighter pilots a tactical altitude advantage. With today's fast and highly maneuverable jet fighters, very much higher airway pressures of the order of 8.0 kPa (identical with 60 mmHg) are used. They are used in conjunction with a counterpressure thoracic vest and an anti-G suit for the abdomen and lower body. Pressurization is activated automatically in response to +Gz accelerations, and to a potentially catastrophic loss of cabin pressurization at altitude. During +Gz accelerations, pressure breathing has been shown to maintain cerebral perfusion by raising the systemic arterial pressure, so increasing the level of G-tolerance that is afforded by the use of anti-G suits and seat tilt-back angles alone. This leaves the pilot less reliant on rigorous, and potentially distracting, straining maneuvers. With loss of cabin pressurization at altitude, pressure breathing of 100% oxygen at high airway pressures enables the pilot's alveolar PO(2) to be maintained at a safe level during emergency descent. Introduced in military aviation, pressure breathing for G-tolerance and pressure breathing for altitude presented as concepts that may be of general physiological interest to many anesthesiologists.

Metal composite as backing for ultrasonic transducers dedicated to non-destructive measurements in hostile

International Nuclear Information System (INIS)

Boubenia, R; Rosenkrantz, E; P, P; Ferrandis, J-Y; Despetis, F

2016-01-01

Our team is specialized in ultrasonic measurements in hostile environment especially under high temperatures. There is a need for acoustic transducers capable of continuous measurement at temperatures up to 700°C. To improve the performances of acoustic sensors we focus our works on the realisation and characterisation of transducer backings able to operate under very high temperature. Commercially, they are produced by the incorporation of tungsten powder in a plastic matrix, which limits the working temperature. The realisation of ultrasonic transducers for non-destructive measures at high temperatures requires adequate materials, manufacturing and assembly processes. To produce the backings, composites were made using very ductile metals such as tin and tungsten. These composites are manufactured by uniaxial hot pressing. First, we studied the influence of temperature and pressure on the densification of tin pellets. Then, several specimens made of tin/W were made and characterised by measuring the specific weight, speed and attenuation of sound. The acoustic measures were realised by ultrasonic spectroscopy. This test-bench was designed and tested on control samples of PMMA and on standard backings (epoxy / tungsten). (paper)

Adipsin Concentrations Are Associated with Back Pain Independently of Adiposity in Overweight or Obese Adults

Directory of Open Access Journals (Sweden)

Sharmayne R. E. Brady

2018-02-01

Full Text Available Objective: To compare cardiometabolic risk factors including cytokine and adipokine concentrations between individuals with and without back pain.Methods: In 62 overweight/obese adults (BMI ≥ 25 kg/m2; 23F/39M, we collected data on: self-reported back pain; anthropometry [BMI, waist circumference, body composition (dual energy X-ray absorptiometry—DEXA]; metabolic parameters [fasting glucose; insulin sensitivity (hyperinsulinaemic-euglycaemic clamps]; cardiovascular parameters (blood pressure, lipids; serum inflammation markers [high-sensitivity C-reactive protein (hsCRP; immunoturbidimetric-assay, tumor necrosis factor-alpha (TNF-α, interleukin (IL-6, and IL-10 (multiplex-assay]; and adipokines [leptin, adipsin, resistin, and adiponectin (multiplex-assay].Results: Participants who reported having back pain in the past month (n = 24; 39% had higher BMI (mean ± SD = 33.8 ± 6.3 vs. 30.2 ± 4.1 kg/m2, p = 0.008, fat-mass (39.9 ± 12.3 vs. 33.9 ± 9.8%, p = 0.04, and waist circumference (109.6 ± 16.8 vs. 101.0 ± 9.3 cm, p = 0.01 compared to those without back pain (n = 38; 61%. No differences were observed in cardiometabolic parameters, inflammatory markers, or adiponectin or resistin concentrations. Those reporting back pain had higher adipsin concentrations compared to those without back pain [median (IQR = 744 (472–2,804 vs. 721 (515–867 ng/ml, p = 0.03], with a trend for higher leptin [5.5 (1.5–24.3 vs. 2.3 (1.5–6.7 ng/ml, p = 0.05], both of which persisted after adjustment for age and sex. Adipsin remained associated with back pain independently of adiposity (BMI, waist, fat-mass, or total %body fat; all p ≤ 0.03.Conclusions: Greater obesity, and higher adipsin and leptin concentrations were observed in those who reported back pain in the past month compared to those without back pain, and adipsin was associated with back pain independently of adiposity. Larger studies are needed to determine if adipsin could be a novel

Epidemiology of low back pain.

Science.gov (United States)

Skovron, M L

1992-10-01

At present, although there have been many epidemiological studies of risk factors for low back pain, there are few risk factors established in prospective studies; and our understanding of them remains relatively crude. Individuals in jobs requiring manual materials handling, particularly repeated heavy lifting and lifting while twisting, are at increased risk of back pain leading to work absence. In addition, exposure to whole-body vibration and job requirements for static postures are associated with back pain. Individual trunk strength has not been consistently demonstrated as associated with back pain; although there is some suggestion that when work requirements for heavy lifting exceed individual capacities, back pain is more likely to occur. The pattern of peak age at onset in the 20's is consistent with back pain development early in working life. Among other individual characteristics, only cigarette smoking has consistently been associated with back pain; and the biological mechanism for this finding is not understood. Evidence with respect to spinal flexibility, aerobic capacity, educational attainment and other variables is suggestive but not consistent. There is some evidence that the individual's relation to work, expressed as job satisfaction or supervisor rating, is also related to work absence due to back pain. While it is possible to describe, however crudely, the characteristics placing people at risk for back pain leading to work absence and/or medical attention, the problem of predicting chronicity and thus identifying patients for more intensive clinical intervention remains unresolved. At this time, only age of the patient and certain clinical features of the back pain such as the presence of sciatic symptoms, duration of the current episode, and history of prior episodes are consistently demonstrated predictors. In chronic patients, there is suggestive evidence that spinal flexibility, trunk strength, and certain psychological

Open-Switch Fault Detection Method of a Back-to-Back Converter Using NPC Topology for Wind Turbine Systems

DEFF Research Database (Denmark)

Lee, June-Seok; Lee, Kyo_Beum; Blaabjerg, Frede

2015-01-01

system can break down in the worst case scenario. To improve the reliability of WTG systems, an open-switch fault detection method for back-to-back converters using the NPC topology is required. This study analyzes effects of inner and outer open-switch faults of the NPC rectifier and inverter......In wind turbine generation (WTG) systems, a back-to-back converter with a neutral-point-clamped (NPC) topology is widely used because this topology has more advantages than a conventional two-level topology, particularly when operating at high power. There are 12 switches in the NPC topology....... An open-switch fault in the NPC rectifier of the back-to-back converter leads to the distortion of the input current and torque vibration in the system. Additionally, an open-switch fault in the NPC inverter of the back-to-back converter causes the distortion of the output current. Furthermore, the WTG...

The optimization of molybdenum back contact films for Cu(In,Ga)Se{sub 2} solar cells by the cathodic arc ion plating method

Energy Technology Data Exchange (ETDEWEB)

Cho, Yong Ki, E-mail: choyk@kitech.re.kr [Heat Treatment and Surface Engineering R and D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Gang Sam; Song, Young Sik; Lim, Tae Hong [Heat Treatment and Surface Engineering R and D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Jung, Donggeun [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2013-12-02

Molybdenum back contact films for Cu(In,Ga)Se{sub 2} (CIGS) solar cells have been deposited using DC magnetron sputtering methods. The electronic pathway properties of the molybdenum film have been highly dependent on the working gas pressure in magnetron sputtering, which should be carefully controlled to obtain high conductivity and adhesion. A coating method, cathodic arc ion plating, was used for molybdenum back contact electrode fabrication. The aim of this work was to find a metallization method for CIGS solar cells, which has less sensitivity on the working pressure. The resistivity, grain size, growth structures, stress, and efficiency of the films in CIGS solar cells were investigated. The results reveal that the growth structures of the molybdenum films mainly affect the conductivity. The lowest electrical resistivity of the ion-plated molybdenum films was 6.9 μΩ-cm at a pressure of 0.7 Pa. The electrical resistivity variation showed a gently increasing slope with linearity under a working gas pressure of 13.3 Pa. However, a high value of the residual stress of over 1.3 GPa was measured. In order to reduce stress, titanium film was selected as the buffer layer material, and the back contact films were optimized by double-layer coating of two kinds of hetero-materials with arc ion plating. CIGS solar cells prepared molybdenum films to measure the efficiency and to examine the effects of the back contact electrode. The resistivity, grain size, and surface morphology of molybdenum films were measured by four-point probe, X-ray diffraction, and a scanning electron microscope. The residual stress of the films was calculated from differences in bending curvatures measured using a laser beam. - Highlights: • Molybdenum back contact films for Cu(In,Ga)Se{sub 2} solar cells were prepared by the cathodic arc ion plating. • The lowest electrical resistivity of molybdenum film was 6.9 μΩ-cm. • Titanium buffer layer reduced the compressive residual stress

Short-term outcomes of a back school program for chronic low back pain

NARCIS (Netherlands)

Hodselmans, AP; Jaegers, SM; Goeken, LN; Göeken, L.N.

Objective: To assess the short-term outcome of a back school program for patients suffering from chronic, nonspecific low back pain (LBP). Design: Quasi-experimental cohort study with a waiting list control group. Setting: Dutch rehabilitation department. Participants: Experimental group (n = 14)

Different centre of pressure patterns within the golf stroke II: group-based analysis.

Science.gov (United States)

Ball, K A; Best, R J

2007-05-01

Although the golf coaching literature stresses the importance of weight transfer during the swing, research has been conflicting or lacking statistical support. A potential problem with previous studies is that no attempt was made to account for different movement strategies in the golf swing. This study evaluated the relationship between centre of pressure measures and club head velocity within two previously identified swing styles, the "Front Foot" and "Reverse" styles. Thirty-nine Front Foot golfers and 19 Reverse golfers performed swings with a driver while standing on two force plates. From the force plate data, centre of pressure displacement, velocity, range, and timing parameters were calculated. Correlation and regression analysis indicated that a larger range of centre of pressure and a more rapid centre of pressure movement in the downswing was associated with a larger club head velocity at ball contact for the Front Foot group. For the Reverse golfers, positioning the centre of pressure further from the back foot at late backswing and a more rapid centre of pressure transfer towards the back foot at ball contact was associated with a larger club head velocity at ball contact. This study has highlighted the importance of identifying different movement strategies before evaluating performance measures, as different parameters were found to be important for the Front Foot and Reverse styles.

Application of fine managed pressure drilling technique in complex wells with both blowout and lost circulation risks

Directory of Open Access Journals (Sweden)

Ling Yan

2015-03-01

Full Text Available Fractured carbonate reservoirs are susceptible to blowout and lost circulation during drilling, which not only restricts drilling speed, but also poses big threat to well control. Moreover, there are few technical means available to reconstruct pressure balance in the borehole. Accordingly, the fine managed pressure drilling was used in the drilling of Well GS19 in the Qixia Formation with super-high pressure and narrow density window, which is a success: ① back pressure in the annular spaces will be adjusted to maintain a slightly over-balanced bottom-hole hydraulic pressure, and fluid level in the circulation tank will be kept in a slight dropping state to ensure that natural gas in the formation would not invade into the borehole in a massive volume; ② inlet drilling fluid density will be controlled at around 2.35 g/cm3, back pressures in the annular be maintained at 2–5 MPa, and bottom-hole pressure equivalent circulation density be controlled at 2.46–2.52 g/cm3; ③ during managed pressure drilling operations, if wellhead pressure exceeds or expects to exceed 7 MPa, semi-blind rams will be closed. Fluids will pass through the choke manifold of the rig to the choke manifold specifically for pressure control before entering gas/liquid separators to discharge gas; ④ during tripping back pressure will be kept at less than 5 MPa, volume of injected drilling fluid will be higher than the theoretical volume during tripping out, whereas the volume of returned drilling fluid will be higher than the theoretical volume during the out-tripping. This technique has been applied successfully in the drilling of the Qixia Formation, Liangshan Formation and Longmaxi Formation with a total footage of 216.60 m, as a good attempt in complicated wells with both blowout and lost circulation risks, which can provide valuable experiences and guidance for handling similar complexities in the future.

Non-Linear Back-propagation: Doing Back-Propagation withoutDerivatives of the Activation Function

DEFF Research Database (Denmark)

Hertz, John; Krogh, Anders Stærmose; Lautrup, Benny

1997-01-01

The conventional linear back-propagation algorithm is replaced by a non-linear version, which avoids the necessity for calculating the derivative of the activation function. This may be exploited in hardware realizations of neural processors. In this paper we derive the non-linear back...

Spinal Manipulation for Low-Back Pain

Science.gov (United States)

... V W X Y Z Spinal Manipulation for Low-Back Pain Share: On This Page Introduction Key Points About ... will help ensure coordinated and safe care. About Low-Back Pain Back pain is one of the most common ...

Intentional back flow effects on ruptured steam generator cooldown during a SGTR event for KSNP

International Nuclear Information System (INIS)

Kim, C.W.; Park, S.J.; Choi, C.J.; Seo, J.T.

2004-01-01

For an optimum recovery from a steam generator tube rupture (SGTR) event, the operators are directed to isolate the steam generator (SG) with ruptured tube as early as possible to minimize the radioactive material release. However, the reactor coolant system (RCS) cooldown and depressurization to the shutdown cooling system (SCS) operation conditions using the intact SG only are hard to achieve unless the ruptured SG is properly cooled since the ruptured SG, which is isolated by operator, remains at high temperature even though the RCS has been cooled down. The effects of intentional back flow from the SG secondary side to the RCS through the ruptured U-tube on the the ruptured SG cooldown were evaluated for the pressurized light water reactor, especially for the Korean standard nuclear power plant (KSNP). In order to evaluate the back flow effect, a series of analyses was conducted using the RELAP5/MOD3 computer code. For the first stage of the analysis, the cooldown process by natural circulation in the SG secondary side was simulated for the initial conditions of the ruptured SG cooldown. In the next analysis stage, two methods of the ruptured SG cooldown by using back flow after RCS cooldown were evaluated. One utilizes the steam condensation on the uncovered U-tube surface, and the other is a SG drain and fill. In the former method, SG tubes are exposed to the steam space by draining SG secondary water into the RCS in order to condense the steam directly onto the uncovered tubes. This method showed that the steam condensation decreased SG secondary pressure and temperature rapidly, demonstrating its effectiveness for cooling. However, this process has a limited applicability if the rupture is located at the lower region. The latter method, draining by back flow and filling using the feedwater system was also found to be effective in ruptured SG cooldown and depressurization even if the rupture occurred at the top of the U-tube. It is concluded that the

The Practical Realities of Giving Back

Directory of Open Access Journals (Sweden)

Ashton Bree Wesner

2014-07-01

Full Text Available In this thematic section, authors consider practical ways of giving back to the communities in which they conduct research. Each author discusses their evolving thoughts on how to give back in these practical ways. Some of these authors discuss giving back by giving money, food, rides, parties, and water bottles. In other cases, authors discuss giving back by creating jobs in the short or long term, grant writing, advocacy, and education. Story-telling is also a theme that many of the authors in this section discuss. For some authors, non-material forms of giving back are critical—simply maintaining social ties to the communities in which they worked, or sharing humor. The authors consider the utility of their attempts at giving back, and in some cases present their personal philosophy or guidelines on the subject.

An Optical Characterization of the Effect of High-Pressure Hydrodynamic Cavitation on Diesel

OpenAIRE

Lockett, R. D.; Fatmi, Z.; Kuti, O.; Price, R.

2016-01-01

Most modern high-pressure common rail diesel fuel injection systems employ an internal pressure equalization system in order to provide the force necessary to support needle lift, enabling precise control of the injected fuel mass. This results in the return of a substantial proportion of the high-pressure diesel back to the fuel tank. The diesel fuel flow occurring in the injector spill passages is expected to be a cavitating flow, which is known to promote fuel ageing. The cavitation of die...

Endogenous Opioid Inhibition of Chronic Low Back Pain Influences Degree of Back Pain Relief Following Morphine Administration

Science.gov (United States)

Bruehl, Stephen; Burns, John W.; Gupta, Rajnish; Buvanendran, Asokumar; Chont, Melissa; Schuster, Erik; France, Christopher R.

2014-01-01

Background and Objectives Factors underlying differential responsiveness to opioid analgesic medications used in chronic pain management are poorly understood. We tested whether individual differences in endogenous opioid inhibition of chronic low back pain were associated with magnitude of acute reductions in back pain ratings following morphine administration. Methods In randomized, counterbalanced order over three sessions, 50 chronic low back pain patients received intravenous naloxone (8mg), morphine (0.08 mg/kg), or placebo. Back pain intensity was rated pre-drug and again after peak drug activity was achieved using the McGill Pain Questionnaire-Short Form (Sensory and Affective subscales, VAS intensity measure). Opioid blockade effect measures to index degree of endogenous opioid inhibition of back pain intensity were derived as the difference between pre-to post-drug changes in pain intensity across placebo and naloxone conditions, with similar morphine responsiveness measures derived across placebo and morphine conditions. Results Morphine significantly reduced back pain compared to placebo (MPQ-Sensory, VAS; P effects of opioid blockade on back pain intensity. However, individual differences in opioid blockade effects were significantly associated with degree of acute morphine-related reductions in back pain on all measures, even after controlling for effects of age, sex, and chronic pain duration (P morphine. Conclusions Morphine appears to provide better acute relief of chronic back pain in individuals with lower natural opioidergic inhibition of chronic pain intensity. Possible implications for personalized medicine are discussed. PMID:24553304

Optimization of Tape Winding Process Parameters to Enhance the Performance of Solid Rocket Nozzle Throat Back Up Liners using Taguchi's Robust Design Methodology

Science.gov (United States)

Nath, Nayani Kishore

2017-08-01

The throat back up liners is used to protect the nozzle structural members from the severe thermal environment in solid rocket nozzles. The throat back up liners is made with E-glass phenolic prepregs by tape winding process. The objective of this work is to demonstrate the optimization of process parameters of tape winding process to achieve better insulative resistance using Taguchi's robust design methodology. In this method four control factors machine speed, roller pressure, tape tension, tape temperature that were investigated for the tape winding process. The presented work was to study the cogency and acceptability of Taguchi's methodology in manufacturing of throat back up liners. The quality characteristic identified was Back wall temperature. Experiments carried out using L 9 ' (34) orthogonal array with three levels of four different control factors. The test results were analyzed using smaller the better criteria for Signal to Noise ratio in order to optimize the process. The experimental results were analyzed conformed and successfully used to achieve the minimum back wall temperature of the throat back up liners. The enhancement in performance of the throat back up liners was observed by carrying out the oxy-acetylene tests. The influence of back wall temperature on the performance of throat back up liners was verified by ground firing test.

Back surface studies of Cu(In,Ga)Se2 thin film solar cells

Science.gov (United States)

Simchi, Hamed

Cu(In,Ga)Se2 thin film solar cells have attracted a lot of interest because they have shown the highest achieved efficiency (21%) among thin film photovoltaic materials, long-term stability, and straightforward optical bandgap engineering by changing relative amounts of present elements in the alloy. Still, there are several opportunities to further improve the performance of the Cu(In,Ga)Se2 devices. The interfaces between layers significantly affect the device performance, and knowledge of their chemical and electronic structures is essential in identifying performance limiting factors. The main goal of this research is to understand the characteristics of the Cu(In,Ga)Se2-back contact interface in order to design ohmic back contacts for Cu(In,Ga)Se2-based solar cells with a range of band gaps and device configurations. The focus is on developing either an opaque or transparent ohmic back contact via surface modification or introduction of buffer layers in the back surface. In this project, candidate back contact materials have been identified based on modeling of band alignments and surface chemical properties of the absorber layer and back contact. For the first time, MoO3 and WO 3 transparent back contacts were successfully developed for Cu(In,Ga)Se 2 solar cells. The structural, optical, and surface properties of MoO 3 and WO3 were optimized by controlling the oxygen partial pressure during reactive sputtering and post-deposition annealing. Valence band edge energies were also obtained by analysis of the XPS spectra and used to characterize the interface band offsets. As a result, it became possible to illuminate of the device from the back, resulting in a recently developed "backwall superstrate" device structure that outperforms conventional substrate Cu(In,Ga)Se2 devices in the absorber thickness range 0.1-0.5 microm. Further enhancements were achieved by introducing moderate amounts of Ag into the Cu(In,Ga)Se2 lattice during the co-evaporation method

Pressure prediction model based on artificial neural network optimized by genetic algorithm and its application in quasi-static calibration of piezoelectric high-pressure sensor.

Science.gov (United States)

Gu, Tingwei; Kong, Deren; Jiang, Jian; Shang, Fei; Chen, Jing

2016-12-01

This paper applies back propagation neural network (BPNN) optimized by genetic algorithm (GA) for the prediction of pressure generated by a drop-weight device and the quasi-static calibration of piezoelectric high-pressure sensors for the measurement of propellant powder gas pressure. The method can effectively overcome the slow convergence and local minimum problems of BPNN. Based on test data of quasi-static comparison calibration method, a mathematical model between each parameter of drop-weight device and peak pressure and pulse width was established, through which the practical quasi-static calibration without continuously using expensive reference sensors could be realized. Compared with multiple linear regression method, the GA-BPNN model has higher prediction accuracy and stability. The percentages of prediction error of peak pressure and pulse width are less than 0.7% and 0.3%, respectively.

Evolution of the bi-stable wake of a square-back automotive shape

Science.gov (United States)

Pavia, Giancarlo; Passmore, Martin; Sardu, Costantino

2018-01-01

Square-back shapes are popular in the automotive market for their high level of practicality. These geometries, however, are usually characterised by high drag and their wake dynamics present aspects, such as the coexistence of a long-time bi-stable behaviour and short-time global fluctuating modes that are not fully understood. In the present paper, the unsteady behaviour of the wake of a generic square-back car geometry is characterised with an emphasis on identifying the causal relationship between the different dynamic modes in the wake. The study is experimental, consisting of balance, pressure, and stereoscopic PIV measurements. Applying wavelet and cross-wavelet transforms to the balance data, a quasi-steady correlation is demonstrated between the forces and bi-stable modes. This is investigated by applying proper orthogonal decomposition to the pressure and velocity data sets and a new structure is proposed for each bi-stable state, consisting of a hairpin vortex that originates from one of the two model's vertical trailing edges and bends towards the opposite side as it merges into a single streamwise vortex downstream. The wake pumping motion is also identified and for the first time linked with the motion of the bi-stable vortical structure in the streamwise direction, resulting in out-of-phase pressure variations between the two vertical halves of the model base. A phase-averaged low-order model is also proposed that provides a comprehensive description of the mechanisms of the switch between the bi-stable states. It is demonstrated that, during the switch, the wake becomes laterally symmetric and, at this point, the level of interaction between the recirculating structures and the base reaches a minimum, yielding, for this geometry, a 7% reduction of the base drag compared to the time-averaged result.

Is there a relationship between pain intensity and postural sway in patients with non-specific low back pain?

Science.gov (United States)

Ruhe, Alexander; Fejer, René; Walker, Bruce

2011-07-15

Increased center of pressure excursions are well documented in patients suffering from non-specific low back pain, whereby the altered postural sway includes both higher mean sway velocities and larger sway area. No investigation has been conducted to evaluate a relationship between pain intensity and postural sway in adults (aged 50 or less) with non-specific low back pain. Seventy-seven patients with non-specific low back pain and a matching number of healthy controls were enrolled. Center of pressure parameters were measured by three static bipedal standing tasks of 90 sec duration with eyes closed in narrow stance on a firm surface. The perceived pain intensity was assessed by a numeric rating scale (NRS-11), an equal number of patients (n = 11) was enrolled per pain score. Generally, our results confirmed increased postural instability in pain sufferers compared to healthy controls. In addition, regression analysis revealed a significant and linear increase in postural sway with higher pain ratings for all included COP parameters. Statistically significant changes in mean sway velocity in antero-posterior and medio-lateral direction and sway area were reached with an incremental change in NRS scores of two to three points. COP mean velocity and sway area are closely related to self-reported pain scores. This relationship may be of clinical use as an objective monitoring tool for patients under treatment or rehabilitation.

Combination of taping with Back School in patients with chronic low back pain: a randomized controlled clinical trial

Directory of Open Access Journals (Sweden)

Andres Tana

2016-11-01

Full Text Available Introduction: 70-85% of the general population suffers from back pain. Back School programs have being effective in the treatment of chronic low back pain. Taping may be useful in reducing pain and normalizing muscle function. The objective of this study was to evaluate the effectiveness of the combination of taping with Back School at short- and long-term. Methods: Randomized controlled clinical trial. The experimental group used tape and made Back Scholl and the control group only made Back School. At the beginning and the end of treatment, pain was evaluated with a visual analogue scale, the flexibility determined with the Modified Finger Tip-to-Floor Test and functionality was calculated with the Roland Morris Disability Questionnaire. Depression was recorded with the Depression Beck Inventory just at the beginning. Results: 220 patients were enrolled, only 42 in the experimental group and 33 in the control group completed the treatment. The variation of pain between the first and the fifth session showed no differences between groups regardless of time (p = 0.329. There were no differences between groups in functionality (p = 0.75, flexibility (p = 0.20 and depression. Conclusion: The combination of taping and Back School compared with only Back School was not more effective in reducing pain, increasing functionality and flexibility in patients with chronic low back pain. Key words: Taping; chronic low back pain; spine school; therapy exercises; flexibility; depression.

Effects of High Pressure on Internally Self-Assembled Lipid Nanoparticles

DEFF Research Database (Denmark)

Kulkarni, Chandrashekhar V; Yaghmur, Anan; Steinhart, Milos

2016-01-01

We present the first report on the effects of hydrostatic pressure on colloidally stabilized lipid nanoparticles enveloping inverse nonlamellar self-assemblies in their interiors. These internal self-assemblies were systematically tuned into bicontinuous cubic (Pn3m and Im3m), micellar cubic (Fd3...... the tolerance of lipid nanoparticles [cubosomes, hexosomes, micellar cubosomes, and emulsified microemulsions (EMEs)] for high pressures, confirming their robustness for various technological applications.......We present the first report on the effects of hydrostatic pressure on colloidally stabilized lipid nanoparticles enveloping inverse nonlamellar self-assemblies in their interiors. These internal self-assemblies were systematically tuned into bicontinuous cubic (Pn3m and Im3m), micellar cubic (Fd3m......), hexagonal (H2), and inverse micellar (L2) phases by regulating the lipid/oil ratio as the hydrostatic pressure was varied from atmospheric pressure to 1200 bar and back to atmospheric pressure. The effects of pressure on these lipid nanoparticles were compared with those on their equilibrium bulk...

Oscillatory lower body negative pressure impairs working memory task-related functional hyperemia in healthy volunteers.

Science.gov (United States)

Merchant, Sana; Medow, Marvin S; Visintainer, Paul; Terilli, Courtney; Stewart, Julian M

2017-04-01

Neurovascular coupling (NVC) describes the link between an increase in task-related neural activity and increased cerebral blood flow denoted "functional hyperemia." We previously showed induced cerebral blood flow oscillations suppressed functional hyperemia; conversely functional hyperemia also suppressed cerebral blood flow oscillations. We used lower body negative pressure (OLBNP) oscillations to force oscillations in middle cerebral artery cerebral blood flow velocity (CBFv). Here, we used N-back testing, an intellectual memory challenge as a neural activation task, to test the hypothesis that OLBNP-induced oscillatory cerebral blood flow can reduce functional hyperemia and NVC produced by a working memory task and can interfere with working memory. We used OLBNP (-30 mmHg) at 0.03, 0.05, and 0.10 Hz and measured spectral power of CBFv at all frequencies. Neither OLBNP nor N-back, alone or combined, affected hemodynamic parameters. 2-Back power and OLBNP individually were compared with 2-back power during OLBNP. 2-Back alone produced a narrow band increase in oscillatory arterial pressure (OAP) and oscillatory cerebral blood flow power centered at 0.0083 Hz. Functional hyperemia in response to 2-back was reduced to near baseline and 2-back memory performance was decreased by 0.03-, 0.05-, and 0.10-Hz OLBNP. OLBNP alone produced increased oscillatory power at frequencies of oscillation not suppressed by added 2-back. However, 2-back preceding OLBNP suppressed OLBNP power. OLBNP-driven oscillatory CBFv blunts NVC and memory performance, while memory task reciprocally interfered with forced CBFv oscillations. This shows that induced cerebral blood flow oscillations suppress functional hyperemia and functional hyperemia suppresses cerebral blood flow oscillations. NEW & NOTEWORTHY We show that induced cerebral blood flow oscillations suppress functional hyperemia produced by a working memory task as well as memory task performance. We conclude that oscillatory

Do functional tests predict low back pain?

Science.gov (United States)

Takala, E P; Viikari-Juntura, E

2000-08-15

A cohort of 307 nonsymptomatic workers and another cohort of 123 workers with previous episodes of low back pain were followed up for 2 years. The outcomes were measured by symptoms, medical consultations, and sick leaves due to low back disorders. To study the predictive value of a set of tests measuring the physical performance of the back in a working population. The hypothesis was that subjects with poor functional capacity are liable to back disorders. Reduced functional performance has been associated with back pain. There are few data to show whether reduced functional capacity is a cause or a consequence of pain. Mobility of the trunk in forward and side bending, maximal isokinetic trunk extension, flexion and lifting strength, and static endurance of back extension were measured. Standing balance and foot reaction time were recorded with a force plate. Clinical tests for the provocation of back or leg pain were performed. Gender, workload, age, and anthropometrics were managed as potential confounders in the analysis. Marked overlapping was seen in the measures of the subjects with different outcomes. Among the nonsymptomatic subjects, low performance in tests of mobility and standing balance was associated with future back disorders. Among workers with previous episodes of back pain, low isokinetic extension strength, poor standing balance, and positive clinical signs predicted future pain. Some associations were found between the functional tests and future low back pain. The wide variation in the results questions the value of the tests in health examinations (e.g., in screening or surveillance of low back disorders).

Neural network construction via back-propagation

International Nuclear Information System (INIS)

Burwick, T.T.

1994-06-01

A method is presented that combines back-propagation with multi-layer neural network construction. Back-propagation is used not only to adjust the weights but also the signal functions. Going from one network to an equivalent one that has additional linear units, the non-linearity of these units and thus their effective presence is then introduced via back-propagation (weight-splitting). The back-propagated error causes the network to include new units in order to minimize the error function. We also show how this formalism allows to escape local minima

Evaluation of Low Back and Neck Pain and Disability of Interns at Physiotherapy and Rehabilitation Department of Afyon Kocatepe University

Directory of Open Access Journals (Sweden)

Horata Emel Taşvuran

2017-01-01

Full Text Available Repetitive tasks, high force, direct pressure, and awkward joint and prolonged constrained posture are cited as prime risk factors, making particularly younger adult physiotherapists vulnerable to musculoskeletal injury. Fourth-grade students (interns perform clinical practice at Afyon Kocatepe University Hospital. They apply hydrotherapy, electrotherapy, robotic therapy, virtual reality therapy and exercise therapy to patients (inpatient and outpatient at both orthopaedic and neurology units approximately twelve months. Because we think they are under the risk of low back and neck disorders therefore aim of the present study is to evaluate recent low back and neck pain and disability of them. 50.6% participants had recent low back pain; 52.9% participants reported mild and moderate low back disability. 21.8% participants had recent neck pain; 16% participants showed mild, moderate and severe neck disability. The difference between units related to low back and neck pain or disability wasn’t significant statistically (p>0.05. Most participants announced that they used the body biomechanics correctly (84.1% and took care of ergonomic conditions (91.5%. In conclusion, it is vital to identify prevalence of low back and neck pain among physiotherapy students and take necessary precautions to prevent further problems.

Back Pain

Science.gov (United States)

... addition, there doesn't appear to be one type of mattress that's best for people with back pain. It's probably a ... of Nondiscrimination Advertising Mayo Clinic is a not-for-profit organization ...

Acknowledging the back patient

DEFF Research Database (Denmark)

Damsgaard, Janne Brammer; Bastrup Jørgensen, Lene; Norlyk, Annelise

, Silkeborg Regional Hospital, Regional Hospital Central Jutland, Silkeborg, Denmark 2. Health, Section for Nursing, Aarhus University, Aarhus, Denmark 3. University of Southern Denmark & Vejle Sygehus, Vejle, Denmark keywords:Back Patient, Narrative, Biomedical, Marginalisation, Self-Identity, Ethical......#296 Acknowledging The Back Patient. A Thematic Synthesis Of Qualitative Research. A Systematic Literature Review. Janne Brammer Damsgaard1, Lene Bastrup Jørgensen1, Annelise Norlyk2, Regner Birkelund3 1. Health, Section for Nursing, Aarhus University & Research Unit, Elective Surgery Centre....... Therefore, telling about experiences and perceptions is important for back patients in order to feel accepted and acknowledged. But selfhood cannot be reduced to narrative identity since the identity of the self is only fully revealed the moment we include the ethical dimension including certain norms...

REFLECTANCE PULSE OXIMETRY AT THE FOREHEAD IMPROVES BY PRESSURE ON THE PROBE

NARCIS (Netherlands)

DASSEL, ACM; GRAAFF, R; SIKKEMA, M; ZIJLSTRA, WG; AARNOUDSE, JG

In this study, we investigated the possibility of improving reflectance (back-scatter) pulse oximetry measurements by pressure applied to the probe. Optimal signal detection, with the probe applied to an easily accessible location, is important to prevent erroneous oxygen saturation readouts. At the

Predictive Validity of the STarT Back Tool for Risk of Persistent Disabling Back Pain in a U.S Primary Care Setting.

Science.gov (United States)

Suri, Pradeep; Delaney, Kristin; Rundell, Sean D; Cherkin, Daniel C

2018-04-03

To examine the predictive validity of the Subgrouping for Targeted Treatment (STarT Back) tool for classifying people with back pain into categories of low, medium, and high risk of persistent disabling back pain in U.S. primary care. Secondary analysis of data from participants receiving usual care in a randomized clinical trial. Primary care clinics. Adults (N = 1109) ≥18 years of age with back pain. Those with specific causes of back pain (pregnancy, disc herniation, vertebral fracture, spinal stenosis) and work-related injuries were not included. Not applicable. The original 9-item version of the STarT Back tool, administered at baseline, stratified patients by their risk (low, medium, high) of persistent disabling back pain (STarT Back risk group). Persistent disabling back pain was defined as Roland-Morris Disability Questionnaire scores of ≥7 at 6-month follow-up. The STarT Back risk group was a significant predictor of persistent disabling back pain (PSTarT Back risk groups successfully separated people with back pain into distinct categories of risk for persistent disabling back pain at 6-month follow-up in U.S. primary care. These results were very similar to those in the original STarT Back validation study. This validation study is a necessary first step toward identifying whether the entire STarT Back approach, including matched/targeted treatment, can be effectively used for primary care in the United States. Published by Elsevier Inc.

Film bulk acoustic resonator pressure sensor with self temperature reference

International Nuclear Information System (INIS)

He, X L; Jin, P C; Zhou, J; Wang, W B; Dong, S R; Luo, J K; Garcia-Gancedo, L; Flewitt, A J; Milne, W I

2012-01-01

A novel film bulk acoustic resonator (FBAR) with two resonant frequencies which have opposite reactions to temperature changes has been designed. The two resonant modes respond differently to changes in temperature and pressure, with the frequency shift being linearly correlated with temperature and pressure changes. By utilizing the FBAR's sealed back trench as a cavity, an on-chip single FBAR sensor suitable for measuring pressure and temperature simultaneously is proposed and demonstrated. The experimental results show that the pressure coefficient of frequency for the lower frequency peak of the FBAR sensors is approximately −17.4 ppm kPa −1 , while that for the second peak is approximately −6.1 ppm kPa −1 , both of them being much more sensitive than other existing pressure sensors. This dual mode on-chip pressure sensor is simple in structure and operation, can be fabricated at very low cost, and yet requires no specific package, therefore has great potential for applications. (paper)

A hydronitrogen solid: high pressure ab initio evolutionary structure searches

International Nuclear Information System (INIS)

Hu Anguang; Zhang Fan

2011-01-01

High pressure ab initio evolutionary structure searches resulted in a hydronitrogen solid with a composition of (NH) 4 . The structure searches also provided two molecular isomers, ammonium azide (AA) and trans-tetrazene (TTZ) which were previously discovered experimentally and can be taken as molecular precursors for high pressure synthesis of the hydronitrogen solid. The computed pressure versus enthalpy diagram showed that the transformation pressure to the hydronitrogen solid is 36 GPa from AA and 75 GPa from TTZ. Its metastability was analyzed by the phonon dispersion spectrum and room-temperature vibrational density of state together with the transformation energy barrier back to molecular phases at 298 K. The predicted energy barrier of 0.21 eV/atom means that the proposed hydronitrogen solid should be very stable at ambient conditions. (fast track communication)

The Limits to Giving Back

Directory of Open Access Journals (Sweden)

Jade S. Sasser

2014-07-01

Full Text Available In this thematic section, authors consider the limitations on giving back that they faced in field research, or saw others face. For some authors, their attempts at giving back were severely limited by the scope of their projects, or their understandings of local cultures or histories. For others, very specific circumstances and historical interventions of foreigners in certain places can limit how and to what extent a researcher is able to have a reciprocal relationship with the participating community. Some authors, by virtue of their lesser positions of power relative to those that they were studying, simply decided not to give back to those communities. In each article it becomes apparent that how and in what ways people give back is unique (and limited both to their personal values and the contexts in which they do research.

Modified adjustable suture hang-back recession: Description of technique and comparison with conventional adjustable hang-back recession

Directory of Open Access Journals (Sweden)

Siddharth Agrawal

2017-01-01

Full Text Available Purpose: This study aims to describe and compare modified hang-back recession with the conventional hang-back recession in large angle comitant exotropia (XT. Methods: A prospective, interventional, double-blinded, randomized study on adult patients (>18 years undergoing single eye recession-resection for large angle (>30 prism diopters constant comitant XT was conducted between January 2011 and December 2015. Patients in Group A underwent modified hang-back lateral rectus recession with adjustable knot while in Group B underwent conventional hang-back recession with an adjustable knot. Outcome parameters studied were readjustment rate, change in deviation at 6 weeks, complications and need for resurgery at 6 months. Results: The groups were comparable in terms of age and preoperative deviation. The patients with the modified hang back (Group A fared significantly better (P < 0.05 than those with conventional hang back (Group B in terms of lesser need for adjustment, greater correction in deviation at 6 weeks and lesser need for resurgery at 6 months. Conclusion: This modification offers several advantages, significantly reduces resurgery requirement and has no added complications.

Inversion Therapy: Can It Relieve Back Pain?

Science.gov (United States)

Inversion therapy: Can it relieve back pain? Does inversion therapy relieve back pain? Is it safe? Answers from Edward R. Laskowski, M.D. Inversion therapy doesn't provide lasting relief from back ...

Analysis of Back-to-Back MMC for Medium Voltage Applications under Faulted Condition

DEFF Research Database (Denmark)

Bose, Anurag; Martins, Joäo Pedro Rodrigues; Chaudhary, Sanjay K.

2017-01-01

This paper analyzes a 10MW medium voltage Back-to-Back (BTB) Modular Multilevel Converter (MMC) without a DC-Link capacitor with halfbridge submodules. It focusses on the system behavior under single-line-to-ground (SLG) fault when there is no capacitor on the DC-Link.The fault current is compute...... to prevent DC overvoltages in the sub-modules during faults....

Aspects Regarding the Beneficial Effect of Reflexology in Low Back Pain

Directory of Open Access Journals (Sweden)

Serban GLIGOR

2013-06-01

Full Text Available Reflexology is based on the digital pressure on certain reflex points situated on the sole of the foot, which represents a “map” of the entire body. The aim of this paper is to highlight the importance of reflexology in low back pain treatment. To accomplish the objectives of this paper, a lot of 12 patients, of both genders, with low back pain, was formed. Out of these patients, 66.67% were male and 33.33% were female, the majority coming from an urban area (75%. The average age ± the standard deviation of the patients was 43.58±13.02 years. The group of patients was subdivided into an experimental group, composed of 7 patients (58.33%, who, besides the classic drug treatment, also underwent reflexology, and a control group, composed of 5 patients (41.67%, who underwent only drug treatment. The treatment linked to reflexology was conducted by a single practitioner of reflexology, using the Morrell technique. Both in the case of the experimental group and in the control one there was a statistically significant reduction in finger to ground index (p < 0.01, respectively p< 0.05. Also, there was a highly statistically significant reduction of pain (p<0.01. Due to the small number of patients involved in the study, the data obtained cannot be generalised, as further studies are required to highlight the beneficial effect of reflexology in the case of low back pain.

Is a history of work-related low back injury associated with prevalent low back pain and depression in the general population?

Directory of Open Access Journals (Sweden)

Cassidy J David

2008-02-01

Full Text Available Abstract Background Little is known about the role of prior occupational low back injury in future episodes of low back pain and disability in the general population. We conducted a study to determine if a lifetime history of work-related low back injury is associated with prevalent severity-graded low back pain, depressive symptoms, or both, in the general population. Methods We used data from the Saskatchewan Health and Back Pain Survey – a population-based cross-sectional survey mailed to a random, stratified sample of 2,184 Saskatchewan adults 20 to 69 years of age in 1995. Information on the main independent variable was gathered by asking respondents whether they had ever injured their low back at work. Our outcomes, the 6-month period prevalence of severity-graded low back pain and depressive symptoms during the past week, were measured with valid and reliable questionnaires. The associations between prior work-related low back injury and our outcomes were estimated through multinomial and binary multivariable logistic regression with adjustment for age, gender, and other important covariates. Results Fifty-five percent of the eligible population participated. Of the 1,086 participants who responded to the question about the main independent variable, 38.0% reported a history of work-related low back injury. A history of work-related low back injury was positively associated with low intensity/low disability low back pain (OR, 3.66; 95%CI, 2.48–5.42, with high intensity/low disability low back pain (OR, 4.03; 95%CI, 2.41–6.76, and with high disability low back pain (OR, 6.76; 95%CI, 3.80–12.01. No association was found between a history of work-related low back injury and depression (OR, 0.85; 95%CI, 0.55–1.30. Conclusion Our analysis shows an association between past occupational low back injury and increasing severity of prevalent low back pain, but not depression. These results suggest that past work-related low back injury

Assessment of back pain in horses

International Nuclear Information System (INIS)

Cauvin, E.

1997-01-01

Back pain is common in horses yet, in many cases, a definitive diagnosis remains elusive. The aim of this article is to present a systematic approach to the patient with a suspected back problem. For the present purposes, back pain is defined as pain arising from the thoracolumbar or sacral spine and associated soft tissues. Examination of the pelvis is also included

Grain Entrapment Pressure on the Torso: Can You Breathe while Buried in Grain?

Science.gov (United States)

Moore, Kevin G; Jones, Carol L

2017-04-26

The pressure applied to the chest and back of a simulated grain entrapment victim was measured. Pressure sensors were attached to the chest and back of a manikin that was buried in grain in the vertical position. Measurements were made in four grain types at four grain depths ranging from the top of the manikin's shoulders to 0.61 m (24 in.) over the head. The pressure ranged from 1.6 to 4.0 kPa (0.23 to 0.57 psi). Based on available physiological information, this amount of pressure is unlikely to limit the respiration of an otherwise healthy adult male victim. However, other factors, such as the victim's age, gender, and body position in the grain, may influence respiration. The aspiration of grain appears to be the most likely asphyxiation risk during grain bin entrapment. Entering a grain storage bin is inherently dangerous, and Occupational Safety and Health Administration (OSHA) guidelines for permit-required confined spaces and grain handling facilities must be followed. Due to the risk of grain aspiration during engulfment, the development of safety equipment that could help protect the airway of a victim should be investigated. Copyright© by the American Society of Agricultural Engineers.

Pricing and Inventory Control Strategy for a Periodic-Review Energy Buy-Back System

Institute of Scientific and Technical Information of China (English)

ZHANG Jihong; CHEN Hongqiao; DING Xiaosong; LI Xian

2016-01-01

Along with the rapid development of economics and enhancement of industrialization,the power demand keeps rising and frequently creates mismatch between demand and supply in electricity.This provides miscellaneous energy buy-back programs with great opportunities.Such programs,when activated,offer certain amount of financial compensations to participants for reducing their energy consumption during peak time.They aim at encouraging participants to shift their electricity usage from peak to non-peak time,and thereby release the demand pressure during peak time.This paper considers a periodic-review joint pricing and inventory decision model under an energy buy-back program over finite planning horizons,in which the compensation levels,setup cost and additive random demand function are incorporated.The objective is to maximize a manufacturer's expected total profit.By using Veinott's conditions,it is shown that the manufacturer's optimal decision is a state dependent (s,S,P) policy under a peak market condition,or partly an (s,S,A,P) policy under the normal market condition.

Postural balance in low back pain patients

DEFF Research Database (Denmark)

Maribo, Thomas; Stengaard-Pedersen, Kristian; Jensen, Lone Donbæk

2011-01-01

Low back pain (LBP) patients have poorer postural control compared to healthy controls, and the importance of assessing and addressing balance is a matter of debate. In the clinic, balance is often tested by means of the one leg stand test (OLST) while research often employs center of pressure (Co......P) on a force platform. Portable force platforms might be of clinical relevance, but their reliability for LBP patients in a clinical setting has not been demonstrated. As LBP patients are more dependent on vision compared to healthy controls, the ratio of tests performed with eyes open and eyes closed (Romberg...... Ratio) might be of clinical interest. This study aimed to assess postural balance in LBP patients by analyzing intra-session reliability of CoP parameters on a portable force platform, the Romberg Ratio, and the OLST. Furthermore, we aimed to determine whether CoP parameters and OLST measure identical...

Predictors of Persistent Disability and Back Pain in Older Adults with a New Episode of Care for Back Pain.

Science.gov (United States)

Rundell, Sean D; Sherman, Karen J; Heagerty, Patrick J; Mock, Charles N; Dettori, Nathan J; Comstock, Bryan A; Avins, Andrew L; Nedeljkovic, Srdjan S; Nerenz, David R; Jarvik, Jeffrey G

2017-06-01

 To identify predictors of persistent disability and back pain in older adults.  Prospective cohort study.  Back pain outcomes using longitudinal data registry.  Five thousand two hundred twenty adults age 65 years and older with a new primary care visit for back pain.  Baseline measurements included: demographics, health, and back pain characteristics. We abstracted imaging findings from 348 radiology reports. The primary outcomes were the Roland-Morris Disability Questionnaire (RMDQ) and back pain intensity. We defined persistent disability as RMDQ of 4/24 or higher at both six and 12 months and persistent back pain as pain 3/10 or higher at both six and 12 months.  There were 2,498 of 4,143 (60.3%) participants with persistent disability, and 2,099 of 4,144 (50.7%) had persistent back pain. Adjusted analyses showed the following characteristics most strongly predictive of persistent disability and persistent back pain: sex, race, worse baseline clinical characteristics of back pain, leg pain, back-related disability and duration of symptoms, smoking, anxiety symptoms, depressive symptoms, a history of falls, greater number of comorbidities, knee osteoarthritis, wide-spread pain syndromes, and an index diagnosis of lumbar spinal stenosis. Within the imaging data subset, central spinal stenosis was not associated with disability or pain.  We found that many predictors in older adults were similar to those for younger populations. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Is there a relationship between pain intensity and postural sway in patients with non-specific low back pain?

Directory of Open Access Journals (Sweden)

Fejer René

2011-07-01

Full Text Available Abstract Background Increased center of pressure excursions are well documented in patients suffering from non-specific low back pain, whereby the altered postural sway includes both higher mean sway velocities and larger sway area. No investigation has been conducted to evaluate a relationship between pain intensity and postural sway in adults (aged 50 or less with non-specific low back pain. Methods Seventy-seven patients with non-specific low back pain and a matching number of healthy controls were enrolled. Center of pressure parameters were measured by three static bipedal standing tasks of 90 sec duration with eyes closed in narrow stance on a firm surface. The perceived pain intensity was assessed by a numeric rating scale (NRS-11, an equal number of patients (n = 11 was enrolled per pain score. Results Generally, our results confirmed increased postural instability in pain sufferers compared to healthy controls. In addition, regression analysis revealed a significant and linear increase in postural sway with higher pain ratings for all included COP parameters. Statistically significant changes in mean sway velocity in antero-posterior and medio-lateral direction and sway area were reached with an incremental change in NRS scores of two to three points. Conclusions COP mean velocity and sway area are closely related to self-reported pain scores. This relationship may be of clinical use as an objective monitoring tool for patients under treatment or rehabilitation.

Stress modeling of microdiaphragm pressure sensors

Science.gov (United States)

Tack, P. C.; Busta, H. H.

1986-01-01

A finite element program analysis was used to model the stress distribution of two monocrystalline silicon diaphragm pressure sensors. One configuration consists of an anisotropically backside etched diaphragm into a 250 micron thick, (100) oriented, silicon wafer. The diaphragm and total chip dimensions are given. The device is rigidly clamped on the back to a support substrate. Another configuration consists of a monocrystalline, (100), microdiaphragm which is formed on top of the wafer and whose area is reduced by a factor of 25 over the first configuration. The diaphragm is rigidly clamped to the silicon wafer. The stresses were calculated at a gauge pressure of 300 mm Hg and used to estimate the piezoresistive responses of resistor elements which were placed parallel and perpendicular near the diaphragm edges.

A new automatic blood pressure kit auscultates for accurate reading with a smartphone

OpenAIRE

Wu, Hongjun; Wang, Bingjian; Zhu, Xinpu; Chu, Guang; Zhang, Zhi

2016-01-01

Abstract The widely used oscillometric automated blood pressure (BP) monitor was continuously questioned on its accuracy. A novel BP kit named Accutension which adopted Korotkoff auscultation method was then devised. Accutension worked with a miniature microphone, a pressure sensor, and a smartphone. The BP values were automatically displayed on the smartphone screen through the installed App. Data recorded in the phone could be played back and reconfirmed after measurement. They could also b...

Predicting low back pain outcome following rehabilitation for low back pain.

Science.gov (United States)

Roberts, Andrew J; Dew, Angela; Bridger, Robert; Etherington, John; Kilminster, Shaun

2015-01-01

Psychosocial factors are known to play a key role in determining the progress of back pain patients. However, it is not known whether these factors are applicable to military personnel, who tend to be fitter than the general population. The aim was to identify physical and psychological predictors in a prospective study of the outcome of back pain rehabilitation over 6 months and a longer follow-up time of between 15 and 32 months. Two hundred and fifty military personnel reporting for a residential rehabilitation programme completed a battery of physical and psychological tests. The physical tests included 800 m run time and the Biering-Sorensen test. The psychological/psychosocial measures included items on fear avoidance, self efficacy, anxiety and depression and occupational psychosocial factors such as job satisfaction. Self efficacy and 800 m run time predicted self-reported functional ability at 6 months and medical discharge/return to full fitness at 15–32 months. Patients with 800 m run times of more than 3 minutes 31 seconds had a four times greater chance of medical discharge from the Armed forces. Eight hundred metre run time and self-efficacy were independent predictors of both self-reported functional ability at 6 months and return to full fitness/medical discharge at 15–32 months. Self-efficacy also predicted 40% of the variance in the intensity of back pain and 10% of other non-back pain. Rehabilitation should include greater emphasis on physical fitness and on improving self-efficacy.

Cryogenic and Gas System Piping Pressure Tests (A Collection of PT Permits)

International Nuclear Information System (INIS)

Rucinski, Russell A.

2002-01-01

This engineering note is a collection of pipe pressure testing documents for various sections of piping for the D-Zero cryogenic and gas systems. High pressure piping must conform with FESHM chapter 5031.1. Piping lines with ratings greater than 150 psig have a pressure test done before the line is put into service. These tests require the use of pressure testing permits. It is my intent that all pressure piping over which my group has responsibility conforms to the chapter. This includes the liquid argon and liquid helium and liquid nitrogen cryogenic systems. It also includes the high pressure air system, and the high pressure gas piping of the WAMUS and MDT gas systems. This is not an all inclusive compilation of test documentation. Some piping tests have their own engineering note. Other piping section test permits are included in separate safety review documents. So if it isn't here, that doesn't mean that it wasn't tested. D-Zero has a back up air supply system to add reliability to air compressor systems. The system includes high pressure piping which requires a review per FESHM 5031.1. The core system consists of a pressurized tube trailer, supply piping into the building and a pressure reducing regulator tied into the air compressor system discharge piping. Air flows from the trailer if the air compressor discharge pressure drops below the regulator setting. The tube trailer is periodically pumped back up to approximately 2000 psig. A high pressure compressor housed in one of the exterior buildings is used for that purpose. The system was previously documented, tested and reviewed for Run I, except for the recent addition of piping to and from the high pressure compressor. The following documents are provided for review of the system: (1) Instrument air flow schematic, drg. 3740.000-ME-273995 rev. H; (2) Component list for air system; (3) Pressure testing permit for high pressure piping; (4) Documentation from Run I contained in D-Zero Engineering note

PREVALENCE OF LOW BACK PAIN AND BACK ERGONOMICS AWARENESS AMONG TEACHERS OF SELECTED SECONDARY SCHOOLS IN KANO METROPOLIS

Directory of Open Access Journals (Sweden)

Farida Garba Sumaila

2015-12-01

Full Text Available Background: Low back pain (LBP is regarded as the commonest musculoskeletal problem in the world which affects people across various strata of the society from lay men on the street to teachers as well as health care providers in health institutions. Therefore the purpose of this study is to determine the prevalence of low back pain and back education awareness among secondary school teachers in Kano Metropolis. Methodos: 200 questionnaires were distributed and only 157 were retrieved, one out of which 4 were invalid because of incomplete data so that only 153 were relevant and used for analysis giving a return rate of 76.5%. The study revealed that 96 out of 153 respondents have low back pain implying 62.7% prevalence. The level of back ergonomic awareness on the other hand was found to be moderate (43.1%. Results: Based on the outcomes of the study, it was concluded that there is a high prevalence of low back pain among secondary school teachers in Kano metropolis. However, the level of back ergonomic awareness is moderate. Conclusion: Therefore proper intervention to prevent exposure to LBP among school teachers should be enhanced and teachers should be well educated on the importance of ergonomic intervention in their working environments.

Back pain online: a cross-sectional survey of the quality of web-based information on low back pain.

Science.gov (United States)

Butler, Laura; Foster, Nadine E

2003-02-15

A cross section of Web sites accessible to the general public was surveyed. To evaluate the quality of information on low back pain and its treatment that a "typical" patient user might access on the Internet. Individuals with back pain have a desire to learn about their condition, what to expect, and what they can do about it. Web sites play a potentially useful role in providing information to help people learn about their low back pain and select the most appropriate methods of management. A general search using popular search engines located 60 Web sites about back pain for review. A list of criteria for evaluating and scoring back pain Web sites was established using available literature and current clinical guidelines for the management of acute low back pain. The total quality score (maximum score, 38) was composed of two separate scores: one for general quality of the site (maximum score, 14) and one for site content specific to low back pain (maximum score, 24). Statistical tests, as appropriate, were used to investigate the relation between general indicators of Web site quality and total scores obtained. The quality of the Web sites surveyed was poor, most of them (n = 58, 97%) scoring less than half the maximum available score. The mean total score was 7.4 (range, 2-25). The mean score was 4.9 (range, 1-12) for general Web site quality and 2.4 (range, 1-13) for content specific to low back pain. Web sites providing references, sites created more recently, and sites not created for advertising purposes tended to be of better quality. This study highlighted the poor quality of information, particularly information about low back pain, available to "typical" patient users on the Internet. Health care professionals must have a role in evaluating existing information and in developing good-quality evidence-based Web sites. Patients with back pain should be discouraged from using the Internet as a source of information unless the Web sites they access have

Short-Term Effect of Laser Acupuncture on Lower Back Pain: A Randomized, Placebo-Controlled, Double-Blind Trial

Directory of Open Access Journals (Sweden)

Jae-Young Shin

2015-01-01

Full Text Available Purpose. This trial was performed to investigate the efficacy of laser acupuncture for the alleviation of lower back pain. Methods. This was a randomized, placebo-controlled, double-blind trial. Fifty-six participants were randomly assigned to either the laser acupuncture group (n=28 or the sham laser acupuncture group (n=28. Participants in both groups received three treatment sessions over the course of one week. Thirteen acupuncture points were selected. The visual analogue scale for pain, pressure pain threshold, Patient Global Impression of Change, and Euro-Quality-of-Life Five Dimensions questionnaire (Korean version were used to evaluate the effect of laser acupuncture treatment on lower back pain. Results. There were no significant differences in any outcome between the two groups, although the participants in both groups showed a significant improvement in each assessed parameter relative to the baseline values. Conclusion. Although there was no significant difference in outcomes between the two groups, the results suggest that laser acupuncture can provide effective pain alleviation and can be considered an option for relief from lower back pain. Further studies using long-term intervention, a larger sample size, and rigorous methodology are required to clarify the effect of laser acupuncture on lower back pain.

THE EFFECTS OF BACK EXTENSION TRAINING ON BACK MUSCLE STRENGTH AND SPINAL RANGE OF MOTION IN YOUNG FEMALES

Directory of Open Access Journals (Sweden)

Yıldız Yaprak

2013-04-01

Full Text Available The objective of this study was to determine the effects of a 10-week dynamic back extension training programme and its effects on back muscle strength, back muscle endurance and spinal range of motion (ROM for healthy young females. Seventy-three young females (age: 19.32±1.80 years, height: 158.89±4.71 cm, body weight: 55.67±6.30 kg volunteered for the study. Prior to the training period, all participants completed anthropometric measurements, back muscle strength and endurance test, lateral bending and spinal ROM measurements. After measurements, the participants were divided into two groups. The exercise group (N:35 performed the dynamic back extension exercise 3 days per week for 10 weeks. The control group (N:38 did not participate in any type of exercise. The mixed design ANOVA (group x time was used to determine the difference in pre- and post-training values. The present findings show that there were significant differences between pre-training and post-training values for back muscle strength and spinal ROM in the exercise group. Following the dynamic strength training programme, back muscle strength and spine ROM values except flexion of the lumbar 5-sacrum 1 (L5-S1 segment of the exercise group showed a significant increase when compared with the pre test values. The control group did not show any significant changes when compared with the pre-training values. The results demonstrate that the 10-week dynamic strength training programme was effective for spinal extension ROM and back muscle strength, but there was no change in back muscle endurance. In this context, this programme could potentially be used to prevent the decrease of spinal ROM as well as provide an increase in the fitness parameters of healthy individuals.

Work and back pain: a prospective study of psychological, social and mechanical predictors of back pain severity.

Science.gov (United States)

Christensen, J O; Knardahl, S

2012-07-01

Studies relating occupational psychological and social factors to back pain have traditionally investigated a small number of exposure factors. The current study explored longitudinally a comprehensive set of specific psychological/social and mechanical work factors as predictors of back pain severity (defined as the product of back pain intensity and duration). Employees from 28 organizations in Norway, representing a wide variety of occupations, were surveyed with a follow-up period of 2 years. Several designs were tested: (1) cross-sectional analyses at baseline and follow-up; (2) prospective analyses with baseline exposure; (3) prospective analyses with average exposure over time [(T1+T2)/2]; and (4) prospective analyses with measures of change in exposure from T1 to T2. A total of 2808 employees responded at both time points. Fourteen psychological/social and two mechanical exposures were measured. Odds ratios (ORs) were computed by ordinal logistic regressions. Several psychological/social factors predicted back pain severity. After adjustment for age, sex, skill level, back pain severity at T1 and other exposure factors estimated to be potential confounders, the most consistent predictors of back pain were the protective factors decision control [lowest OR 0.68; 99% confidence interval (CI): 0.49-0.95], empowering leadership (lowest OR 0.59; 99% CI: 0.38-0.91) and fair leadership (lowest OR 0.54; 99% CI: 0.34-0.87). Some of the most important predictors included in this study were factors that have previously received little attention in back pain research. This emphasizes the importance of extending the list of factors possibly contributing to back pain. © 2011 National Institute of Occupational Health, Norway European Journal of Pain © 2011 European Federation of International Association for the Study of Pain Chapters.

Influence of low back pain and prognostic value of MRI in sciatica patients in relation to back pain.

Science.gov (United States)

el Barzouhi, Abdelilah; Vleggeert-Lankamp, Carmen L A M; Lycklama à Nijeholt, Geert J; Van der Kallen, Bas F; van den Hout, Wilbert B; Koes, Bart W; Peul, Wilco C

2014-01-01

Patients with sciatica frequently complain about associated back pain. It is not known whether there are prognostic relevant differences in Magnetic Resonance Imaging (MRI) findings between sciatica patients with and without disabling back pain. The study population contained patients with sciatica who underwent a baseline MRI to assess eligibility for a randomized trial designed to compare the efficacy of early surgery with prolonged conservative care for sciatica. Two neuroradiologists and one neurosurgeon independently evaluated all MR images. The MRI readers were blinded to symptom status. The MRI findings were compared between sciatica patients with and without disabling back pain. The presence of disabling back pain at baseline was correlated with perceived recovery at one year. Of 379 included sciatica patients, 158 (42%) had disabling back pain. Of the patients with both sciatica and disabling back pain 68% did reveal a herniated disc with nerve root compression on MRI, compared to 88% of patients with predominantly sciatica (Psciatica at baseline was negatively associated with perceived recovery at one year (Odds ratio [OR] 0.32, 95% Confidence Interval 0.18-0.56, PSciatica patients with disabling back pain in absence of nerve root compression on MRI at baseline reported less perceived recovery at one year compared to those with predominantly sciatica and nerve root compression on MRI (50% vs 91%, PSciatica patients with disabling low back pain reported an unfavorable outcome at one-year follow-up compared to those with predominantly sciatica. If additionally a clear herniated disc with nerve root compression on MRI was absent, the results were even worse.

High Pressure Electrolyzer System Evaluation

Science.gov (United States)

Prokopius, Kevin; Coloza, Anthony

2010-01-01

This report documents the continuing efforts to evaluate the operational state of a high pressure PEM based electrolyzer located at the NASA Glenn Research Center. This electrolyzer is a prototype system built by General Electric and refurbished by Hamilton Standard (now named Hamilton Sunstrand). It is capable of producing hydrogen and oxygen at an output pressure of 3000 psi. The electrolyzer has been in storage for a number of years. Evaluation and testing was performed to determine the state of the electrolyzer and provide an estimate of the cost for refurbishment. Pressure testing was performed using nitrogen gas through the oxygen ports to ascertain the status of the internal membranes and seals. It was determined that the integrity of the electrolyzer stack was good as there were no appreciable leaks in the membranes or seals within the stack. In addition to the integrity testing, an itemized list and part cost estimate was produced for the components of the electrolyzer system. An evaluation of the system s present state and an estimate of the cost to bring it back to operational status was also produced.

Mechanical effects of strong measurement: back-action noise and cooling

Science.gov (United States)

Schwab, Keith

2007-03-01

Our recent experiments show that it is now possible to prepare and measure mechanical systems with thermal occupation factors of N˜25 and perform continuous position measurements close to the limits required by the Heisenberg Uncertainty Principle (1). I will discuss our back-action measurements with nanomechanical structures strongly coupled to single electron transistors. We have been able to observe the stochastic back-action forces exerted by the SET as well as a cooling effect which has analogies to cooling in optical cavities. Furthermore, I will discuss progress using optical fields coupled to mechanical modes which show substantial cooling using the pondermotive effects of the photons impacting a flexible dielectric mirror (2). Both of these techniques pave the way to demonstrating the true quantum properties of a mechanical device: squeezed states, superposition states, and entangled states. (1) ``Quantum Measurement Backaction and Cooling Observed with a Nanomechanical Resonator,'' A. Naik, O. Buu, M.D. LaHaye, M.P. Blencowe, A.D. Armour, A.A. Clerk, K.C. Schwab, Nature 443, 193 (2006). (2) ``Self-cooling of a micro-mirror by radiation pressure,'' S. Gigan, H.R. Boehm, M. Patemostro, F. Blaser, G. Langer, J. Hertzberg, K. Schwab, D. Baeuerle, M. Aspelmeyer, A. Zeilinger, Nature 444, 67 (2006).

Lumbopelvic Core Stabilization Exercise and Pain Modulation Among Individuals with Chronic Nonspecific Low Back Pain.

Science.gov (United States)

Paungmali, Aatit; Joseph, Leonard H; Sitilertpisan, Patraporn; Pirunsan, Ubon; Uthaikhup, Sureeporn

2017-11-01

Lumbopelvic stabilization training (LPST) may provide therapeutic benefits on pain modulation in chronic nonspecific low back pain conditions. This study aimed to examine the effects of LPST on pain threshold and pain intensity in comparison with the passive automated cycling intervention and control intervention among patients with chronic nonspecific low back pain. A within-subject, repeated-measures, crossover randomized controlled design was conducted among 25 participants (7 males and 18 females) with chronic nonspecific low back pain. All the participants received 3 different types of experimental interventions, which included LPST, the passive automated cycling intervention, and the control intervention randomly, with 48 hours between the sessions. The pressure pain threshold (PPT), hot-cold pain threshold, and pain intensity were estimated before and after the interventions. Repeated-measures analysis of variance showed that LPST provided therapeutic effects as it improved the PPT beyond the placebo and control interventions (P pain intensity under the LPST condition was significantly better than that under the passive automated cycling intervention and controlled intervention (P pain threshold under the LPST condition also showed a significant trend of improvement beyond the control (P pain threshold were evident. Lumbopelvic stabilization training may provide therapeutic effects by inducing pain modulation through an improvement in the pain threshold and reduction in pain intensity. LPST may be considered as part of the management programs for treatment of chronic low back pain. © 2017 World Institute of Pain.

Back analysis of an earthquake-triggered submarine landslide near the SW of Xiaoliuqiu

Directory of Open Access Journals (Sweden)

Huai-Houh Hsu

2018-01-01

Full Text Available Occurred in the offshore of SW Taiwan on 26 December 2006 with a magnitude of 7, the Pingtung earthquake had triggered numbers of submarine landslides. This event provides an excellent opportunity to incorporate the back analysis approach to evaluate the in situ shear strength parameters. According to the chirp sonar images of the seabed near the SW Xiaoliuqiu obtained before and after the earthquake were adopted to establish the slope profile and identified the location of a circular sliding surface. Consequently, the in situ, effective strength parameters under the critical condition can be calculated by back slope stability analysis. Submarine sediment sampler was obtained via gravity sampling method and the laboratory tests were performed to determine the index properties and strength parameters. Test results indicate the cored sediment has the characteristics of normally consolidated (NC clay. The effective friction angle (φ’ is 15.3° with cohesion (c’ of 19.4 kPa. The effective and total stress methods were used to perform the back analysis. The strength parameters derived from back analysis of effective and total stress methods all indicate values approach the CIU triaxial tests results. Consequently, the representativeness of the marine sediment characteristics obtained from laboratory tests is identified. The total stress approach yields an undrained strength ratio cu/σ'vo of 0.26 which well fit the ratio used in geotechnical practice for estimating NC clay. According to the analytical approach, the landslide was applied seismic forces (seismic coefficient kh = 0.14 and generated excess pore pressure of 31 kPa at the sliding surface.

Back scattering involving embedded silicon nitride (SiN) nanoparticles for c-Si solar cells

Science.gov (United States)

Ghosh, Hemanta; Mitra, Suchismita; Siddiqui, M. S.; Saxena, A. K.; Chaudhuri, Partha; Saha, Hiranmay; Banerjee, Chandan

2018-04-01

A novel material, structure and method of synthesis for dielectric light trapping have been presented in this paper. First, the light scattering behaviour of silicon nitride nanoparticles have been theoretically studied in order to find the optimized size for dielectric back scattering by FDTD simulations from Lumerical Inc. The optical results have been used in electrical analysis and thereby, estimate the effect of nanoparticles on efficiency of the solar cells depending on substrate thickness. Experimentally, silicon nitride (SiN) nanoparticles have been formed using hydrogen plasma treatment on SiN layer deposited by Plasma Enhanced Chemical Vapour Deposition (PECVD). The size and area coverage of the nanoparticles were controlled by varying the working pressure, power density and treatment duration. The nanoparticles were integrated with partial rear contact c-Si solar cells as dielectric back reflector structures for the light trapping in thin silicon solar cells. Experimental results revealed the increases of current density by 2.7% in presence of SiN nanoparticles.

Text mining a self-report back-translation.

Science.gov (United States)

Blanch, Angel; Aluja, Anton

2016-06-01

There are several recommendations about the routine to undertake when back translating self-report instruments in cross-cultural research. However, text mining methods have been generally ignored within this field. This work describes a text mining innovative application useful to adapt a personality questionnaire to 12 different languages. The method is divided in 3 different stages, a descriptive analysis of the available back-translated instrument versions, a dissimilarity assessment between the source language instrument and the 12 back-translations, and an item assessment of item meaning equivalence. The suggested method contributes to improve the back-translation process of self-report instruments for cross-cultural research in 2 significant intertwined ways. First, it defines a systematic approach to the back translation issue, allowing for a more orderly and informed evaluation concerning the equivalence of different versions of the same instrument in different languages. Second, it provides more accurate instrument back-translations, which has direct implications for the reliability and validity of the instrument's test scores when used in different cultures/languages. In addition, this procedure can be extended to the back-translation of self-reports measuring psychological constructs in clinical assessment. Future research works could refine the suggested methodology and use additional available text mining tools. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Laser heat hyperalgesia is not a feature of non-specific chronic low back pain.

Science.gov (United States)

Franz, M; Ritter, A; Puta, C; Nötzel, D; Miltner, W H R; Weiss, T

2014-11-01

Based upon studies using mechanical pin-prick, pressure, electrical or heat stimuli applied to painful and/or pain-free parts of the body, chronic low back pain (CLBP) has been shown to be associated with generalized and enhanced pain sensitivity and altered brain responses to noxious stimuli. To date, no study examined the processing of noxious laser heat pulses, which are known to selectively excite thermal nociceptors located in the superficial skin layers, in CLBP. We studied laser heat pain thresholds (LHPTs) and nociceptive laser-evoked brain electrical potentials (LEPs) following skin stimulation of the pain-affected back and the pain-free abdomen using noxious laser heat stimulation in 16 CLBP patients and 16 age- and gender-matched healthy controls (HCs). We observed no statistically significant differences in LHPTs between CLBP patients and HCs, neither on the back nor on the abdomen. Furthermore, we found no evidence for altered brain responses between CLBP patients and HCs in response to stimulation of the back and abdomen in single-trial latencies and amplitudes of LEP components (N2, P2). The results are in contrast to previous studies showing hypersensitivity to different experimental noxious stimuli (e.g., contact heat). We argue that these discrepancies may be due to low spatial and temporal summation within the central nervous system following laser heat stimulation. Our results indicate important methodological differences between laser heat and thermode stimulation that should be taken into account when interpreting results, such as from thermal quantitative sensory testing. © 2014 European Pain Federation - EFIC®

Uncertainty Analyses for Back Projection Methods

Science.gov (United States)

Zeng, H.; Wei, S.; Wu, W.

2017-12-01

So far few comprehensive error analyses for back projection methods have been conducted, although it is evident that high frequency seismic waves can be easily affected by earthquake depth, focal mechanisms and the Earth's 3D structures. Here we perform 1D and 3D synthetic tests for two back projection methods, MUltiple SIgnal Classification (MUSIC) (Meng et al., 2011) and Compressive Sensing (CS) (Yao et al., 2011). We generate synthetics for both point sources and finite rupture sources with different depths, focal mechanisms, as well as 1D and 3D structures in the source region. The 3D synthetics are generated through a hybrid scheme of Direct Solution Method and Spectral Element Method. Then we back project the synthetic data using MUSIC and CS. The synthetic tests show that the depth phases can be back projected as artificial sources both in space and time. For instance, for a source depth of 10km, back projection gives a strong signal 8km away from the true source. Such bias increases with depth, e.g., the error of horizontal location could be larger than 20km for a depth of 40km. If the array is located around the nodal direction of direct P-waves the teleseismic P-waves are dominated by the depth phases. Therefore, back projections are actually imaging the reflection points of depth phases more than the rupture front. Besides depth phases, the strong and long lasted coda waves due to 3D effects near trench can lead to additional complexities tested here. The strength contrast of different frequency contents in the rupture models also produces some variations to the back projection results. In the synthetic tests, MUSIC and CS derive consistent results. While MUSIC is more computationally efficient, CS works better for sparse arrays. In summary, our analyses indicate that the impact of various factors mentioned above should be taken into consideration when interpreting back projection images, before we can use them to infer the earthquake rupture physics.

Laid Back Avant-Garde

DEFF Research Database (Denmark)

Degn Johansson, Troels

2010-01-01

controversial. Whereas Laid Back has been one of the largest commercial successes of the Danish music industry due to the success of a handful of pop hits (in Germany, mainly), the duo has never been recognized for its artistic contribution. A few years after his public statement, von Trier directed...... the official music video for Laid Back’s Bakerman single, where the duo and a backing group dressed up as bakers is seen performing while skydiving. Rather than approaching this video as an illustration of the song, the paper suggests that the Bakerman video should be seen as the result of a curatorial act...... where Lars von Trier seeks to elaborate on his particular fondness of the values that this pop duo seems to represent for him; simplicity, popularity (in Danish “folkelighed”), and irony. In this sense, by promoting the Laid Back single by means of a music video, von Trier’s contribution leads us rather...

The United States Army Low Back Pain Workshop,

Science.gov (United States)

1986-07-01

obtained in weightlifting , twists, turns, lifting heights, operational heights, etc. 4. Establish training programs in back injury prevention and care...Back pain, complaints, problems, injuries , prention 19 ABSTRACT (Continue on reverse if necessary and identify by block numbe)resentations covered: Low...Back Injury Prevention Program; Striving to Prevent Back Injury , A Historical Perspective; The Data Picture--Collection and Use; An Approach to the

Pressure-induced phase transitions in nanocrystalline ReO3

International Nuclear Information System (INIS)

Biswas, Kanishka; Muthu, D V S; Sood, A K; Kruger, M B; Chen, B; Rao, C N R

2007-01-01

Pressure-induced phase transitions in the nanocrystals of ReO 3 with an average diameter of ∼12 nm have been investigated in detail by using synchrotron x-ray diffraction and the results compared with the literature data of bulk samples of ReO 3 . The study shows that the ambient-pressure cubic I phase (space group Pm3-barm) transforms to a monoclinic phase (space group C 2/c), then to a rhombohedral I phase (space group R3-barc), and finally to another rhombohedral phase (rhombohedral II, space group R3-barc) with increasing pressure over the 0.0-20.3 GPa range. The cubic I to monoclinic transition is associated with the largest volume change (∼5%), indicative of a reconstructive transition. The transition pressures are generally lower than those known for bulk ReO 3 . The cubic II (Im3-bar) or tetragonal (P4/mbm) phases do not occur at lower pressures. The nanocrystals are found to be more compressible than bulk ReO 3 . On decompression to ambient pressure, the structure does not revert back to the cubic I structure

Space Vector Modulation for DC-Link Current Ripple Reduction in Back-To-Back Current Source Converters for Microgrid Applications

DEFF Research Database (Denmark)

Guo, Xiaoqiang; Xu, David; Guerrero, Josep M.

2015-01-01

Back-to-back converters have been typically used to interconnect the microgrids. For a back-to-back current source converter, the dc-link current ripple is one of the important parameters. A large ripple will cause the electromagnetic interference, undesirable high-frequency losses, and system...... instability. Conventionally, with a given switching frequency and rated voltage, the current ripple can be reduced by increasing the dc-link inductor, but it leads to bulky size, high cost and slow dynamic response. In order to solve this problem, this paper reveals that the current ripple can...

Compression Stockings and Pressure Ulcers: Case Series of a Neglected Issue.

Science.gov (United States)

Rathore, Farooq A; Ahmad, Faria; Khan, Omer J

2017-10-10

Pressure ulcers develop in patients who endure long periods of immobilization, often caused by conditions such as musculoskeletal and neurological diseases. Pressure ulcers adversely affect the patient and increase caregiver burden and healthcare costs. Typical sites for these ulcers include the sacrum, trochanters, and heels; they also occur on the nape of the neck, penis, nostrils, helix of the ear, and upper back. Compression stockings are commonly used to prevent and stop the progression of venous disorders, including deep vein thrombosis, but their role in the development of pressure ulcers is not well known. We describe three case reports of pressure ulcer development due to prolonged application of compression stockings. In each case, the nursing staff who were primarily responsible for the prevention of pressure ulcers applied the stockings continuously without any intermittent relief. Moreover, the stockings did not include manufacturer instructions, such as recommended exposure times and applications. We recommend that nursing staff be trained in pressure relief and prevention of pressure ulcers, including rare occurrences, and that manufacturers give detailed guidance regarding the safe use of compression stockings.

Flexible distribution systems through the application of multi back-to-back converters. Concept, implementation and experimental verification

Energy Technology Data Exchange (ETDEWEB)

De Graaff, R A.A.

2010-05-26

The objective of the research project is to investigate the use of a multi back-to-back converter to support the transition to active distribution networks. The investigation must explicitly not focus on finding the optimal power electronics topology, but rather on defining the role that such a device can play in a power distribution system and on the proof of principle. The possible tasks of this device are to actively control power flow and to maintain power quality and stability, both during normal operation and during fault conditions in medium voltage networks with distributed generation. The combination of this versatile converter system and the control and protection systems that define its functionality are in this thesis denoted as the Intelligent Node (IN). Research questions are: (1) Which are the main benefits of multi back-to-back converter devices in distribution systems?; (2) How and under which conditions can these benefits be achieved? What controls should be adopted?; (3) Which are the specific aspects that distinguish the application of the multi back-to-back devices in distribution systems from similar applications in transmission systems?; (4) Can this be demonstrated on a laboratory-scale set-up?Chapter 2 Distribution systems The relevant aspects of distribution systems are discussed. This includes power quality considerations, redundancy aspects, and voltage control methods. Chapter 3 (FACTS in distribution systems) describes power flow control principles. Also an overview is given of the state-of-the-art of power electronic applications for power flow control in electrical power systems. Chapter 4 (Functional concept of the Intelligent Node) gives the proposed functional concept for the application of a multi back-to-back converter device as IN (Intelligent Node). The applications are developed on a functional level, with the device at a black-box level. To satisfy the resulting requirements several technology options are analyzed, ending

Correlations in back-to-back hadron production in SIDIS

Energy Technology Data Exchange (ETDEWEB)

Avakian, Harut [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pisano, Silvia [National Inst. of Nuclear Physics (INFN), Frascati (Italy). National Lab. of Frascati (INFN-LNF)

2016-08-01

The Deep Inelastic Scattering (DIS) proved to be a great tool in testing of the theory of strong in- teractions. Semi-Inclusive DIS (SIDIS), with detection of an additional hadron allowed first stud- ies of 3D structure of the nucleon, moving the main focus from testing the QCD to understanding of strong interactions and quark gluon dynamics to address a number of puzzles accumulated in recent years. Detection of two hadrons in SIDIS, which is even more complicated, provides ac- cess to details of quark gluon interactions inaccessible in single-hadron SIDIS, providing a new avenue to study the complex nucleon structure. Large acceptance of the CLAS detector at Jef- ferson Lab, allowing detection of two hadrons, produced back-to-back (b2b) in the current and target fragmentation regions, provides a unique possibility to study the nucleon structure in target fragmentation region, and correlations of target and current fragmentation regions

Fighting Back

Science.gov (United States)

Academe, 2005

2005-01-01

In this new feature of the "Academe" journal, work by faculty members is highlighted who are mobilizing in support of academic freedom on their campuses and beyond. This September-October issue of the journal includes the following brief reflections from faculty all relating to the central theme of "fighting back": "Free…

Lifting Safety: Tips To Help Prevent Back Injuries

Science.gov (United States)

... Prevent Back Injuries Lifting Safety: Tips to Help Prevent Back Injuries Share Print Back injuries are common problems at work, home, and play. They can be caused by accidents or improper lifting technique. Below are tips to ...

Chronic Localized Back Pain Due to Posterior Cutaneous Nerve Entrapment Syndrome (POCNES): A New Diagnosis.

Science.gov (United States)

Boelens, Oliver B; Maatman, Robert C; Scheltinga, Marc R; van Laarhoven, Kees; Roumen, Rudi M

2017-03-01

Most patients with chronic back pain suffer from degenerative thoracolumbovertebral disease. However, the following case illustrates that a localized peripheral nerve entrapment must be considered in the differential diagnosis of chronic back pain. We report the case of a 26-year-old woman with continuous excruciating pain in the lower back area. Previous treatment for nephroptosis was to no avail. On physical examination the pain was present in a 2 x 2 cm area overlying the twelfth rib some 4 cm lateral to the spinal process. Somatosensory testing using swab and alcohol gauze demonstrated the presence of skin hypo- and dysesthesia over the painful area. Local pressure on this painful spot elicited an extreme pain response that did not irradiate towards the periphery. These findings were highly suggestive of a posterior version of the anterior cutaneous nerve entrapment syndrome (ACNES), a condition leading to a severe localized neuropathic pain in anterior portions of the abdominal wall. She demonstrated a beneficial albeit temporary response after lidocaine infiltration as dictated by an established diagnostic and treatment protocol for ACNES. She subsequently underwent a local neurectomy of the involved superficial branch of the intercostal nerve. This limited operation had a favorable outcome resulting in a pain-free return to normal activities up to this very day (follow-up of 24 months).We propose to name this novel syndrome "posterior cutaneous nerve entrapment syndrome" (POCNES). Each patient with chronic localized back pain should undergo simple somatosensory testing to detect the presence of overlying skin hypo- and dysesthesia possibly reflecting an entrapped posterior cutaneous nerve.Key words: Chronic pain, back pain, posterior cutaneous nerve entrapment, peripheral nerve entrapment, surgical treatment for pain, anterior cutaneous nerve entrapment.

Back Analysis of the Permeability Coefficient of a High Core Rockfill Dam Based on a RBF Neural Network Optimized Using the PSO Algorithm

Directory of Open Access Journals (Sweden)

Shichun Chi

2015-01-01

Full Text Available It is important to determine the seepage field parameters of a high core rockfill dam using the seepage data obtained during operation. For the Nuozhadu high core rockfill dam, a back analysis model is proposed using the radial basis function neural network optimized using a particle swarm optimization algorithm (PSO-RBFNN and the technology of finite element analysis for solving the saturated-unsaturated seepage field. The recorded osmotic pressure curves of osmometers, which are distributed in the maximum cross section, are applied to this back analysis. The permeability coefficients of the dam materials are retrieved using the measured seepage pressure values while the steady state seepage condition exists; that is, the water lever remains unchanged. Meanwhile, the parameters are tested using the unstable saturated-unsaturated seepage field while the water level rises. The results show that the permeability coefficients are reasonable and can be used to study the real behavior of a seepage field of a high core rockfill dam during its operation period.

Chronic low back pain in patients with systemic lupus erythematosus: prevalence and predictors of back muscle strength and its correlation with disability

Directory of Open Access Journals (Sweden)

Raíssa Sudré Cezarino

Full Text Available Abstract Objective: To determine the prevalence of Chronic Low Back Pain and predictors of Back Muscle Strength in patients with Systemic Lupus Erythematosus. Methods: Cross-sectional study. Ninety-six ambulatory patients with lupus were selected by non-probability sampling and interviewed and tested during medical consultation. The outcomes measurements were: Point prevalence of chronic low back pain, Oswestry Disability Index, Tampa Scale of Kinesiophobia, Fatigue Severity Scale and maximal voluntary isometric contractions of handgrip and of the back muscles. Correlation coefficient and multiple linear regression were used in statistical analysis. Results: Of the 96 individuals interviewed, 25 had chronic low back pain, indicating a point prevalence of 26% (92% women. The correlation between the Oswestry Index and maximal voluntary isometric contraction of the back muscles was r = −0.4, 95% CI [−0.68; −0.01] and between the maximal voluntary isometric contraction of handgrip and of the back muscles was r = 0.72, 95% CI [0.51; 0.88]. The regression model presented the highest value of R 2 being observed when maximal voluntary isometric contraction of the back muscles was tested with five independent variables (63%. In this model handgrip strength was the only predictive variable (β = 0.61, p = 0.001. Conclusions: The prevalence of chronic low back pain in individuals with systemic lupus erythematosus was 26%. The maximal voluntary isometric contraction of the back muscles was 63% predicted by five variables of interest, however, only the handgrip strength was a statistically significant predictive variable. The maximal voluntary isometric contraction of the back muscles presented a linear relation directly proportional to handgrip and inversely proportional to Oswestry Index i.e. stronger back muscles are associated with lower disability scores.

Pressure vessel codes: Their application to nuclear reactor systems

International Nuclear Information System (INIS)

1966-01-01

A survey has been made by the International Atomic Energy Agency of how the problems of applying national pressure vessel codes to nuclear reactor systems have been treated in those Member States that had pressurized reactors in operation or under construction at the beginning of 1963. Fifteen answers received to an official inquiry form the basis of this report, which also takes into account some recently published material. Although the answers to the inquiry in some cases data back to 1963 and also reflect the difficulty of describing local situations in answer to standard questions, it is hoped that the report will be of interest to reactor engineers. 21 refs, 1 fig., 2 tabs

Investigating Research Gaps of Pharmaceutical take back Events: An Analysis of take back Program Participants' Socioeconomic, Demographic, and Geographic Characteristics and the Public Health Benefits of take back Programs

Science.gov (United States)

Stoddard, K. I.; Hodge, V.; Maxey, G.; Tiwari, C.; Cready, C.; Huggett, D. B.

2017-06-01

Research continues to show that pharmaceutical environmental contamination causes adverse effects to aquatic life. There are also public health risks associated with pharmaceuticals because in-home reserves of medications provide opportunities for accidental poisoning and intentional medication abuse. Pharmaceutical take back programs have been seen as a potential remedy for these issues; however, a thorough review of past programs indicates limited research has been conducted on take back programs. Furthermore, there are significant gaps in take back program research. To address these gaps and ultimately determine if take back programs could improve public health, research was conducted in conjunction with the take back program Denton drug disposal days held in Denton, Texas. Socioeconomic, demographic, and geographic characteristics of Denton drug disposal days participants were investigated using surveys and Geographic Information Systems. Potential impacts of the Denton drug disposal days program on public health were determined by comparing data from Denton drug disposal days events with data supplied by the North Texas Poison Center. Results suggest that Denton drug disposal days events may have prevented accidental poisonings or intentional abuse, however only qualitative comparisons support this statement and there was insufficient empirical evidence to support the conclusion that Denton drug disposal days events were exclusively responsible for public health improvements. An interesting finding was that there was a definitive travel threshold that influenced participation in Denton drug disposal days events. Overall, this study fills some geographic, socioeconomic, and demographic data gaps of take back programs and proposes methods to analyze and improve participation in future take back programs. These methods could also be applied to improve participation in other local environmentally-focused programs such as household hazardous collection events.

Investigating Research Gaps of Pharmaceutical take back Events: An Analysis of take back Program Participants' Socioeconomic, Demographic, and Geographic Characteristics and the Public Health Benefits of take back Programs.

Science.gov (United States)

Stoddard, K I; Hodge, V; Maxey, G; Tiwari, C; Cready, C; Huggett, D B

2017-06-01

Research continues to show that pharmaceutical environmental contamination causes adverse effects to aquatic life. There are also public health risks associated with pharmaceuticals because in-home reserves of medications provide opportunities for accidental poisoning and intentional medication abuse. Pharmaceutical take back programs have been seen as a potential remedy for these issues; however, a thorough review of past programs indicates limited research has been conducted on take back programs. Furthermore, there are significant gaps in take back program research. To address these gaps and ultimately determine if take back programs could improve public health, research was conducted in conjunction with the take back program Denton drug disposal days held in Denton, Texas. Socioeconomic, demographic, and geographic characteristics of Denton drug disposal days participants were investigated using surveys and Geographic Information Systems. Potential impacts of the Denton drug disposal days program on public health were determined by comparing data from Denton drug disposal days events with data supplied by the North Texas Poison Center. Results suggest that Denton drug disposal days events may have prevented accidental poisonings or intentional abuse, however only qualitative comparisons support this statement and there was insufficient empirical evidence to support the conclusion that Denton drug disposal days events were exclusively responsible for public health improvements. An interesting finding was that there was a definitive travel threshold that influenced participation in Denton drug disposal days events. Overall, this study fills some geographic, socioeconomic, and demographic data gaps of take back programs and proposes methods to analyze and improve participation in future take back programs. These methods could also be applied to improve participation in other local environmentally-focused programs such as household hazardous collection events.

Element nodes of sports equipment double back flip factions and double back flip hunched performed gymnast in floor exercise

Directory of Open Access Journals (Sweden)

V.A. Potop

2014-07-01

Full Text Available Purpose: to identify the node elements of sports equipment double back somersault tuck and double back flip bent. To compare the two types of nodes for double somersault. Material : the study involved eight gymnasts (age 12 - 14 years. All finalists in the competition floor exercise - reserve team Romania. The method of video - computer research and method of postural orientation movements. Results : identified nodal elements of sports equipment double back somersault tuck and double back flip bent. In the preparatory phase of motor actions - launcher body posture for reaching is repulsive to flip. In the phase of basic motor action - animation body postures (double back somersault tuck and bent (bent double back flip. Exercises are performed on the ascending and descending parts of the flight path of the demonstration of individual maximum lift height common center of mass. In the final phase of motor actions - final body posture - steady landing. Conclusions : indicators of key elements of sports equipment acrobatic exercises contain new scientific facts kinematic and dynamic structures of motor actions. They are necessary for the development of modern training programs acrobatic exercises in step specialized base preparation.

National supply-chain survey of drug manufacturer back orders.

Science.gov (United States)

Wellman, G S

2001-07-01

The impact of manufacturer back orders on the supply chain for pharmaceuticals in the institutional setting was studied. A questionnaire was distributed during May and June 2000 to 600 institutional pharmacies affiliated with a major national drug and supply group purchasing organization. The instrument included questions on basic institutional demographics, perceptions about the frequency of manufacturer back orders for pharmaceuticals, the quality of communication with manufacturers and wholesalers about back orders, the two most significant back orders that had occurred in the 12 months preceding the survey, and the reasons for and impact of back orders. A total of 170 usable surveys were returned (net response rate, 28.3%). Reported manufacturer back orders included an array of drug classes, including blood products, antimicrobials, antiarrhythmics, benzodiazepine antagonists, thrombolytics, corticosteroids, and antihypertensives. Respondents perceived significant back orders as increasing in frequency. Communication by manufacturers and wholesalers about back orders was reported to be relatively poor. A raw-material shortage was the most common reason given by manufacturers for back orders (36.5%), followed by a regulatory issue (23.2%). In most cases (92%), medical staff members had to be contacted, indicating an interruption in the normal drug distribution process. In over a third of instances, respondents stated that the back order resulted in less optimal therapy. A survey found that manufacturer back orders for pharmaceuticals were increasing in frequency and that information flow within the supply chain was insufficient to meet the needs of end users.

Attention modulates sensory suppression during back movements.

Science.gov (United States)

Van Hulle, Lore; Juravle, Georgiana; Spence, Charles; Crombez, Geert; Van Damme, Stefaan

2013-06-01

Tactile perception is often impaired during movement. The present study investigated whether such sensory suppression also occurs during back movements, and whether this would be modulated by attention. In two tactile detection experiments, participants simultaneously engaged in a movement task, in which they executed a back-bending movement, and a perceptual task, consisting of the detection of subtle tactile stimuli administered to their upper or lower back. The focus of participants' attention was manipulated by raising the probability that one of the back locations would be stimulated. The results revealed that tactile detection was suppressed during the execution of the back movements. Furthermore, the results of Experiment 2 revealed that when the stimulus was always presented to the attended location, tactile suppression was substantially reduced, suggesting that sensory suppression can be modulated by top-down attentional processes. The potential of this paradigm for studying tactile information processing in clinical populations is discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

Pressure induced phase transitions in ceramic compounds containing tetragonal zirconia

Energy Technology Data Exchange (ETDEWEB)

Sparks, R.G.; Pfeiffer, G.; Paesler, M.A.

1988-12-01

Stabilized tetragonal zirconia compounds exhibit a transformation toughening process in which stress applied to the material induces a crystallographic phase transition. The phase transition is accompanied by a volume expansion in the stressed region thereby dissipating stress and increasing the fracture strength of the material. The hydrostatic component of the stress required to induce the phase transition can be investigated by the use of a high pressure technique in combination with Micro-Raman spectroscopy. The intensity of Raman lines characteristic for the crystallographic phases can be used to calculate the amount of material that has undergone the transition as a function of pressure. It was found that pressures on the order of 2-5 kBar were sufficient to produce an almost complete transition from the original tetragonal to the less dense monoclinic phase; while a further increase in pressure caused a gradual reversal of the transition back to the original tetragonal structure.

Back pain in seniors: the Back pain Outcomes using Longitudinal Data (BOLD) cohort baseline data.

Science.gov (United States)

Jarvik, Jeffrey G; Comstock, Bryan A; Heagerty, Patrick J; Turner, Judith A; Sullivan, Sean D; Shi, Xu; Nerenz, David R; Nedeljkovic, Srdjan S; Kessler, Larry; James, Kathryn; Friedly, Janna L; Bresnahan, Brian W; Bauer, Zoya; Avins, Andrew L; Deyo, Richard A

2014-04-23

Back pain represents a substantial burden globally, ranking first in a recent assessment among causes of years lived with disability. Though back pain is widely studied among working age adults, there are gaps with respect to basic descriptive epidemiology among seniors, especially in the United States. Our goal was to describe how pain, function and health-related quality of life vary by demographic and geographic factors among seniors presenting to primary care providers with new episodes of care for back pain. We examined baseline data from the Back pain Outcomes using Longitudinal Data (BOLD) registry, the largest inception cohort to date of seniors presenting to a primary care provider for back pain. The sample included 5,239 patients ≥ 65 years old with a new primary care visit for back pain at three integrated health systems (Northern California Kaiser-Permanente, Henry Ford Health System [Detroit], and Harvard Vanguard Medical Associates [Boston]). We examined differences in patient characteristics across healthcare sites and associations of patient sociodemographic and clinical characteristics with baseline patient-reported measures of pain, function, and health-related quality of life. Patients differed across sites in demographic and other characteristics. The Detroit site had more African-American patients (50%) compared with the other sites (7-8%). The Boston site had more college graduates (68%) compared with Detroit (20%). Female sex, lower educational status, African-American race, and older age were associated with worse functional disability as measured by the Roland-Morris Disability Questionnaire. Except for age, these factors were also associated with worse pain. Baseline pain and functional impairment varied substantially with a number of factors in the BOLD cohort. Healthcare site was an important factor. After controlling for healthcare site, lower education, female sex, African-American race, and older age were associated with worse

Efficacy of transverse tripolar spinal cord stimulator for the relief of chronic low back pain from failed back surgery.

Science.gov (United States)

Buvanendran, Asokumar; Lubenow, Timothy J

2008-01-01

Failed back surgery syndrome is a common clinical entity for which spinal cord stimulation has been found to be an effective mode of analgesia, but with variable success rates. To determine if focal stimulation of the dorsal columns with a transverse tripolar lead might achieve deeper penetration of the electrical stimulus into the spinal cord and therefore provide greater analgesia to the back. Case report. We describe a 42-year-old female with failed back surgery syndrome that had greater back pain than leg pain. The tripolar lead configuration was achieved by placing percutaneously an octapolar lead in the spinal midline followed by 2 adjacent quadripolar leads, advanced to the T7-T10 vertebral bodies. Tripolar stimulation pattern resulted in more than 70% pain relief in this patient during the screening trial, while stimulation of one or 2 electrodes only provided 20% pain relief. After implantation of a permanent tripolar electrode system with a single rechargeable battery, the pain relief was maintained for one year. This is case report describing a case of a patient with chronic low back pain with a diagnosis of failed back surgery syndrome in which transverse tripolar stimulation using an octapolar and 2 quadripolar leads appeared to be beneficial. The transverse tripolar system consists of a central cathode surrounded by anodes, using 3 leads. This arrangement may contribute to maximum dorsal column stimulation with minimal dorsal root stimulation and provide analgesia to the lower back.

Asset backed securities : risks, ratings and quantitative modelling

NARCIS (Netherlands)

Jönsson, B.H.B.; Schoutens, W.

2009-01-01

Asset backed securities (ABSs) are structured finance products backed by pools of assets and are created through a securitisation process. The risks in asset backed securities, such as, credit risk, prepayment risk, market risks, operational risk, and legal risks, are directly connected with the

Characteristics of Bilayer Molybdenum Films Deposited Using RF Sputtering for Back Contact of Thin Film Solar Cells

Directory of Open Access Journals (Sweden)

Sea-Fue Wang

2014-01-01

Full Text Available Mo films prepared under a single deposition condition seldom simultaneously obtain a low resistivity and a good adhesion necessary for use in solar cells. In order to surmount the obstacle, bilayer Mo films using DC sputtering at a higher working pressure and a lower working pressure have been attempted as reported in the literature. In this study, RF sputtering with different powers in conjunction with different working pressures was explored to prepare bilayer Mo film. The first bottom layer was grown at a RF sputtering power of 30 W and a working pressure of 12 mTorr, and the second top layer was deposited at 100 W and 4.5 mTorr. The films revealed a columnar growth with a preferred orientation along the (110 plane. The bilayer Mo films reported an electrical resistivity of 6.35 × 10−5 Ω-cm and passed the Scotch tape test for adhesion to the soda-lime glass substrate, thereby qualifying the bilayer Mo films for use as back metal contacts for CIGS substrates.

Control of relative radiation pressure in optical traps : application to phagocytic membrane binding studies

NARCIS (Netherlands)

Kress, H.; Stelzer, E.H.K.; Griffiths, G.; Rohrbach, A.

2005-01-01

We show how to control the relative radiation pressure and thereby the stable trap position of an optically trapped bead by variation of the mean incident axial photon momentum. The thermal position fluctuations of a trapped bead are recorded by a three-dimensional back focal plane interferometry.

Comparison of low back mobility and stability exercises from Pilates in non-specific low back pain: A study protocol of a randomized controlled trial.

Science.gov (United States)

Miranda, Iã Ferreira; Souza, Catiane; Schneider, Alexandre Tavares; Chagas, Leandro Campos; Loss, Jefferson Fagundes

2018-05-01

There is some evidence in the literature about the effectiveness of the Pilates methods in the low back pain. Moreover, Pilates focus on exercises that empathizes the stability and/or mobility of the spine. Therefore, it is discussed in the literature whether higher levels of stability or mobility of the lumbar spine generates better results, both in performance and rehabilitation for low back pain. Compare the effects of the low back mobility and stability exercises from Pilates Method on low back pain, disability and movement functionality in individuals with non-specific chronic low back pain. 28 participants will be randomized into two exercise protocol from Pilates methods, one focusing on low back stability and other on low back mobility. Low back pain (visual analogic scale), low back disability (Oswestry) and movement functionality (7 functional movement tasks) will be evaluated before and after 10 sessions of Pilates exercise by the same trained assessor. A mixed designed ANOVA with two factors will be used. This study is the first to compare these outcomes for chronic low back pain participants with two exercises protocol focusing on low back mobility and stability and the results will evaluate what to prioritize with Pilates exercises to give better results for that population. Copyright © 2017 Elsevier Ltd. All rights reserved.

Particle image velocimetry investigation of a finite amplitude pressure wave

Science.gov (United States)

Thornhill, D.; Currie, T.; Fleck, R.; Chatfield, G.

2006-03-01

Particle image velocimetry is used to study the motion of gas within a duct subject to the passage of a finite amplitude pressure wave. The wave is representative of the pressure waves found in the exhaust systems of internal combustion engines. Gas particles are accelerated from stationary to 150 m/s and then back to stationary in 8 ms. It is demonstrated that gas particles at the head of the wave travel at the same velocity across the duct cross section at a given point in time. Towards the tail of the wave viscous effects are plainly evident causing the flow profile to tend towards parabolic. However, the instantaneous mean particle velocity across the section is shown to match well with the velocity calculated from a corresponding measured pressure history using 1D gas dynamic theory. The measured pressure history at a point in the duct was acquired using a high speed pressure transducer of the type typically used for engine research in intake and exhaust systems. It is demonstrated that these are unable to follow the rapid changes in pressure accurately and that they are prone to resonate under certain circumstances.

SURGTANK, Steam Pressure, Saturation Temperature or Reactor Surge Tank

International Nuclear Information System (INIS)

Gorman, D.J.; Gupta, R.K.

2001-01-01

the heat transferred to the walls and down into the liquid content of the tank is computed. The equation of state is utilized to obtain ambient temperature at the end of the interval. Deviations of the steam from perfect gas theory are taken into account. An energy balance is determined for the end of interval in keeping with the first law of thermodynamics. Any imbalance is designed as error, stored, and the procedure is repeated with a slightly higher assumed pressure. These calculations are repeated until a change in sign of the error is noted, and the exact pressure can be determined. The properties calculated for the end of the first level and time increment are used as the starting proper- ties of the second increment, etc. Calculations are terminated when the final level is reached. 3 - Restrictions on the complexity of the problem: The program was developed for predicting pressure behavior in vertical axis cylindrical tanks with spherical dome caps. It could be readily adapted to other geometries, such as spherical tanks (reference 2). Back-to-back insurges and outsurges cannot be treated since each must start from equilibrium conditions. The analysis does not include the effects of heaters, sprays, and safety valves. Possible modifications to include effects of sprays are discussed in reference 5

Low back pain during pregnancy

Directory of Open Access Journals (Sweden)

Maria Emília Coelho Costa Carvalho

2017-05-01

Full Text Available Objective: Low back pain is a common complaint among pregnant women. It is estimated that about 50% of pregnant women complain of some form of back pain at some point in pregnancy or during the postpartum period. The aim of this study was to evaluate the frequency of low back pain during pregnancy and its characteristics. Methods: Cross-sectional study with low-risk pregnant women. After approval by the Human Research Ethics Committee and receiving written informed consent, we included pregnant women over 18 years of age and excluded those with psychiatric disorders, previous lumbar pathologies, and receiving treatment for low back pain. Results: We interviewed 97 pregnant women. The frequency of low back pain was 68%. The mean age was 26.2 years and the median gestational age was 30 weeks. Fifty-eight pregnant women declared themselves as brown (58%. Most (88.6% were married or living in common-law marriage, 56 (57.7% worked outside the home, and 71 (73.2% had completed high school. Low back pain was more frequent during the second trimester of pregnancy (43.9%, referred to as a “burning” sensation in 37.8% of patients, with intermittent frequency in 96.9% of the women. The symptoms got worse at night (71.2%. Resting reduced low back pain in 43.9% of pregnant women, while the standing position for a long time worsened it in 27.2% of patients. Conclusion: Low back pain is common in pregnant women, has specific characteristics, and is more frequent in the second trimester of pregnancy. This indicates the need for prevention strategies that enable better quality of life for pregnant women. Resumo: Objetivo: A lombalgia é uma queixa comum entre grávidas. Estima-se que cerca de 50% das gestantes queixam-se de algum tipo de dor lombar em algum momento da gravidez ou durante o puerpério. O objetivo deste estudo foi avaliar a frequência da lombalgia na gestação e suas características. Método: Estudo de corte transversal com gestantes de

Does weather affect daily pain intensity levels in patients with acute low back pain? A prospective cohort study.

Science.gov (United States)

Duong, Vicky; Maher, Chris G; Steffens, Daniel; Li, Qiang; Hancock, Mark J

2016-05-01

The aim of this study was to investigate the influence of various weather parameters on pain intensity levels in patients with acute low back pain (LBP). We performed a secondary analysis using data from the PACE trial that evaluated paracetamol (acetaminophen) in the treatment of acute LBP. Data on 1604 patients with LBP were included in the analysis. Weather parameters (precipitation, temperature, relative humidity, and air pressure) were obtained from the Australian Bureau of Meteorology. Pain intensity was assessed daily on a 0-10 numerical pain rating scale over a 2-week period. A generalised estimating equation analysis was used to examine the relationship between daily pain intensity levels and weather in three different time epochs (current day, previous day, and change between previous and current days). A second model was adjusted for important back pain prognostic factors. The analysis did not show any association between weather and pain intensity levels in patients with acute LBP in each of the time epochs. There was no change in strength of association after the model was adjusted for prognostic factors. Contrary to common belief, the results demonstrated that the weather parameters of precipitation, temperature, relative humidity, and air pressure did not influence the intensity of pain reported by patients during an episode of acute LBP.

Exercise therapy for chronic nonspecific low-back pain

NARCIS (Netherlands)

van Middelkoop, Marienke; Rubinstein, Sidney M; Verhagen, Arianne P; Ostelo, Raymond W; Koes, Bart W; van Tulder, Maurits W

Exercise therapy is the most widely used type of conservative treatment for low back pain. Systematic reviews have shown that exercise therapy is effective for chronic but not for acute low back pain. During the past 5 years, many additional trials have been published on chronic low back pain. This

26 CFR 1.460-6 - Look-back method.

Science.gov (United States)

2010-04-01

...) for the redetermination year, as adjusted for past applications of the look-back method and taking... the year in question with respect to other contracts. Notwithstanding the look-back method, the...) INCOME TAXES Taxable Year for Which Items of Gross Income Included § 1.460-6 Look-back method. (a) In...

Psychometric Properties of the Japanese Version of the STarT Back Tool in Patients with Low Back Pain.

Science.gov (United States)

Matsudaira, Ko; Oka, Hiroyuki; Kikuchi, Norimasa; Haga, Yuri; Sawada, Takayuki; Tanaka, Sakae

2016-01-01

The STarT Back Tool uses prognostic indicators to classify patients with low back pain into three risk groups to guide early secondary prevention in primary care. The present study aimed to evaluate the psychometric properties of the Japanese version of the tool (STarT-J). An online survey was conducted among Japanese patients with low back pain aged 20-64 years. Reliability was assessed by examining the internal consistency of the overall and psychosocial subscales using Cronbach's alpha coefficients. Spearman's correlation coefficients were used to evaluate the concurrent validity between the STarT-J total score/psychosocial subscore and standard reference questionnaires. Discriminant validity was evaluated by calculating the area under the curves (AUCs) for the total and psychosocial subscale scores against standard reference cases. Known-groups validity was assessed by examining the relationship between low back pain-related disability and STarT-J scores. The analysis included data for 2000 Japanese patients with low back pain; the mean (standard deviation [SD]) age was 47.7 (9.3) years, and 54.1% were male. The mean (SD) STarT-J score was 2.2 (2.1). The Cronbach's alpha coefficient was 0.75 for the overall scale and 0.66 for the psychosocial subscale. Spearman's correlation coefficients ranged from 0.30 to 0.59, demonstrating moderate to strong concurrent validity. The AUCs for the total score ranged from 0.65 to 0.83, mostly demonstrating acceptable discriminative ability. For known-groups validity, participants with more somatic symptoms had higher total scores. Those in higher STarT-J risk groups had experienced more low back pain-related absences. The overall STarT-J scale was internally consistent and had acceptable concurrent, discriminant, and known-groups validity. The STarT-J can be used with Japanese patients with low back pain.

Rehabilitation of Low Back Pain in Golfers

OpenAIRE

Finn, Christopher

2013-01-01

Context: Low back injuries are the most common injury in golf. Best practice guidelines for rehabilitation and prevention of these injuries are helpful for health care professionals and all golfers. Objective: To establish a best practice clinical model for low back pain in golfers from diagnosis through treatment and rehabilitation to return to golf. Evidence Acquisition: The PubMed database and Google Scholar were searched from 1993 to 2012 with the following keywords: golf and low back inj...

Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

DEFF Research Database (Denmark)

Krogsbøll, Anette Susanne; Fuglsang, Leif D

2006-01-01

The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor...

Welding repair of the high-intermediate pressure steam casings made of Cr-Mo and Cr-Mo-V steel

International Nuclear Information System (INIS)

Mazur, Z.; Cristalinas, V.; Kubiak, J.

1996-01-01

An analysis of typical failure causes and their location at high-intermediate pressure steam turbine casing, and weldability analysis of the Cr-Mo and Cr-Mo-V steels, is carried out. basing on the steam turbine of 158 MW capacity, the internal high pressure casing failures and development of in situ repair welding technology is described. After repair, the casing was put back into service

Numerical simulation of transitions between back discharge regimes

International Nuclear Information System (INIS)

Jansky, Jaroslav; Lemont, Florent; Bessieres, Delphine; Paillol, Jean

2014-01-01

This paper presents numerical simulations of transitions between back discharge regimes. Back discharge refers to any discharge initiated at or near a dielectric layer covering a passive electrode. In this work, a pinhole in a dielectric layer on a plane anode serves as a model for back discharge activity. We have studied transitions between back discharge regimes by varying the surface charge density on the dielectric layer and the electric field in front of the pinhole. From the variation of these two independent parameters, the back discharge regimes have been depicted as a mode diagram inspired by the experimental study of Masuda and Mizuno. The resulting diagram includes the different discharge regimes that are commonly observed in experiments. The propagation of a positive ionizing wave inside the pinhole toward its edge, and the resulting formation of a plasma zone at its exit constitute the onset stage of back discharge. From this stage, the transitions to volume discharge or surface discharge can occur. The volume discharge regime consists of the propagation of a discharge in space toward the cathode which can be superimposed with the propagation of a discharge above the dielectric layer surface. The diagram reveals the conditions for transitions between back discharge regimes. (authors)

Low back pain in military recruits in relation to social background and previous low back pain. A cross-sectional and prospective observational survey

Directory of Open Access Journals (Sweden)

Weidick Flemming

2005-05-01

Full Text Available Abstract Background Traditionally, studies on the etiology of low back pain have been carried out in adult populations. However, since low back pain often appears early in life, more research on young populations is needed. This study focuses on the importance of social background factors and previous low back pain in the development of low back pain in military recruits. Methods During a three-month period, Danish military recruits with different social backgrounds live and work under the same conditions. Thus, there is an opportunity to investigate the influence of social background on the development of low back pain, when persons are removed from their usual environment and submitted to a number of new stressors. In addition, the importance of the recruits' previous low back pain history in relation to low back pain during military service was studied. This was done by means of questionnaires to 1,711 recruits before and after this three-month period. Results Sedentary occupation was negatively associated with long-lasting low back pain (>30 days during the past year at baseline with an odds ratios of 0.55 (95% CI: 0.33–0.90. This effect vanished during service. Having parents with higher education increased the risk of low back pain during service (OR: 1.9;1.2–3.0, for the highest educated group, but not of the consequences (leg pain and exemption from duty, whereas high IQ decreased the risk of these consequences (odds ratios as low as 0.2;0.1–0.8 for exemption from duty in the group with highest IQ. Long-lasting low back pain prior to service increased the risk of long-lasting low back pain (OR: 4.8;2.1–10.8, leg pain (OR: 3.3;1.3–8.3 and exemption from duty during service (OR: 5.9;2.4–14.8. Conclusion Sedentary occupation is negatively associated with low back pain at baseline. This protective effect disappears, when the person becomes physically active. For predicting trouble related to the low back during service, the

Studies of the nucleon structure in back-to-back SIDIS

International Nuclear Information System (INIS)

Avakian, H.

2016-01-01

The Deep Inelastic Scattering (DIS) proved to be a great tool in testing of the theory of strong interactions, which was a major focus in last decades. Semi-Inclusive DIS (SIDIS), with detection of an additional hadron allowed first studies of 3D structure of the nucleon, moving the main focus from testing the QCD to understanding of strong interactions and quark gluon dynamics to address a number of puzzles accumulated in recent years. Detection of two hadrons in SIDIS, which is even more complicated, provides access to details of quark gluon interactions inaccessible in single-hadron SIDIS, providing a new avenue to study the complex nucleon structure. Large acceptance of the Electron Ion Collider, allowing detection of two hadrons, produced back-to-back in the current and target fragmentation regions, combined with clear separation of two regions, would provide a unique possibility to study the nucleon structure in target fragmentation region, and correlations of target and current fragmentation regions. (authors)

Studies of the nucleon structure in back-to-back SIDIS

Energy Technology Data Exchange (ETDEWEB)

Avakian, Harut [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2016-03-01

The Deep Inelastic Scattering (DIS) proved to be a great tool in testing of the theory of strong interactions, which was a major focus in last decades. Semi-Inclusive DIS (SIDIS), with detection of an additional hadron allowed first studies of 3D structure of the nucleon, moving the main focus from testing the QCD to understanding of strong interactions and quark gluon dynamics to address a number of puzzles accumulated in recent years. Detection of two hadrons in SIDIS, which is even more complicated, provides access to details of quark gluon interactions inaccessible in single-hadron SIDIS, providing a new avenue to study the complex nucleon structure. Large acceptance of the Electron Ion Collider, allowing detection of two hadrons, produced back-to-back in the current and target fragmentation regions, combined with clear separation of two regions, would provide a unique possibility to study the nucleon structure in target fragmentation region, and correlations of target and current fragmentation regions.

Low back pain in military recruits in relation to social background and previous low back pain. A cross-sectional and prospective observational survey

DEFF Research Database (Denmark)

Hestbæk, Lise; Larsen, K.; Weidich, F.

2005-01-01

back pain in the development of low back pain in military recruits. METHODS: During a three-month period, Danish military recruits with different social backgrounds live and work under the same conditions. Thus, there is an opportunity to investigate the influence of social background......BACKGROUND: Traditionally, studies on the etiology of low back pain have been carried out in adult populations. However, since low back pain often appears early in life, more research on young populations is needed. This study focuses on the importance of social background factors and previous low...... on the development of low back pain, when persons are removed from their usual environment and submitted to a number of new stressors. In addition, the importance of the recruits' previous low back pain history in relation to low back pain during military service was studied. This was done by means of questionnaires...

Harmonic models of a back-to-back converter in large offshore wind farms compared with measurement data

DEFF Research Database (Denmark)

Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth

2009-01-01

The offshore wind farm with installed back-to-back power converter in wind turbines is studied. As an example the Burbo Bank offshore wind farm with Siemens Wind Power wind turbines is taken into consideration. The wind farm is simulated in DIgSILENT Power Factory software in order to determine...

Reducing the cost of back-contact module technology

Energy Technology Data Exchange (ETDEWEB)

Bennett, I.J.; Eerenstein, W.; Rosca, V. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands)

2013-07-01

Back-contact modules made using a conductive back-sheet foil have a number of advantages over standard H-pattern modules including a higher power output, compatibility with very thin cells and high throughput, high yield manufacturing. For a conductive back-sheet based module the most cost critical components are the conductive back-sheet and the conductive adhesives used to make the contact between the cells and the conductive back-sheet. In this paper a number of methods for reducing the module materials cost will be presented. Climate chamber testing of low cost foils without isolation coating and without silver contacts demonstrated that this type of foil is reliable in damp-heat, reaching 2000 hours at 85%RH and 85{sup o}C with a loss in fill-factor of less than 2%.

Influence of low back pain and prognostic value of MRI in sciatica patients in relation to back pain

NARCIS (Netherlands)

A. el Barzouhi (Abdelilah); C.L.A.M. Vleggeert-Lankamp (Carmen); G.J.L.A. Nijeholt (Geert J. Lycklama A); B.F.W. van der Kallen (Bas); W.B. van den Hout (Wilbert); B.W. Koes (Bart); W.C. Peul (Wilco)

2014-01-01

textabstractBackground: Patients with sciatica frequently complain about associated back pain. It is not known whether there are prognostic relevant differences in Magnetic Resonance Imaging (MRI) findings between sciatica patients with and without disabling back pain. Methods: The study population

Back muscle strength, lifting, and stooped working postures.

Science.gov (United States)

Poulsen, E; Jørgensen, K

1971-09-01

When lifting loads and working in a forward stooped position, the muscles of the back rather than the ligaments and bony structures of the spine should overcome the gravitational forces. Formulae, based on measurements of back muscle strength, for prediction of maximal loads to be lifted, and for the ability to sustain work in a stooped position, have been worked out and tested in practical situations. From tests with 50 male and female subjects the simplest prediction formulae for maximum loads were: max. load = 1.10 x isometric back muscle strength for men; and max. load = 0.95 x isometric back muscle strength - 8 kg for women. Some standard values for maximum lifts and permissible single and repeated lifts have been calculated for men and women separately and are given in Table 1. From tests with 65 rehabilitees it was found that the maximum isometric strength of the back muscles measured at shoulder height should exceed 2/3 of the body weight, if fatigue and/or pain in the back muscles is to be avoided during work in a standing stooped position.

Returning to sports after a back injury

Science.gov (United States)

... medlineplus.gov/ency/patientinstructions/000518.htm Returning to sports after a back injury To use the sharing ... Back pain - returning to sports Which Type of Sport is Best? In deciding when and if to ...

Molybdenum thin film deposited by in-line DC magnetron sputtering as a back contact for Cu(In,Ga)Se{sub 2} solar cells

Energy Technology Data Exchange (ETDEWEB)

Li Zhaohui; Cho, Eou-Sik [Department of Electronics Engineering, Kyungwon University, San 65, Bokjung-dong, Soojung-gu, Seongnam city, Kyunggi-do, 461-701 (Korea, Republic of); Kwon, Sang Jik, E-mail: sjkwon@kyungwon.ac.kr [Department of Electronics Engineering, Kyungwon University, San 65, Bokjung-dong, Soojung-gu, Seongnam city, Kyunggi-do, 461-701 (Korea, Republic of)

2011-09-01

In this paper, we reported the effect of the power and the working pressure on the molybdenum (Mo) films deposited using an in-line direct current (DC) magnetron sputtering system. The electrical and the structural properties of Mo film were improved by increasing DC power from 1 to 3 kW. On the other side, the resistivity of the Mo films became higher with the increasing working pressure. However, the adhesion property was improved when the working pressure was higher. In this work, in order to obtain an optimal Mo film as a back metal contact of Cu(In,Ga)Se{sub 2} (CIGS) solar cells, a bilayer Mo film was formed through the different film structures depending on the working pressure. The first layer was formed at a high pressure of 12 mTorr for a better adhesion and the second layer was formed at a low pressure of 3 mTorr for a lower resistivity.

BURT: back up and restore tool

Energy Technology Data Exchange (ETDEWEB)

Karonis, N.T.

1994-11-01

BURT is just one of the tools in the Experimental Physics Industrial Control System (EPICS). In this document we address the problem of backing up and restoring sets of values in databases whose values are continuously changing. In doing so, we present the Back Up and Restore Tool (BURT). In this presentation we provide a theoretical framework that defines the problem and lays the foundation for its solution. BURT is a tool designed and implemented with respect to that theoretical framework. It is not necessary for users of BURT to have an understanding of that framework. It was included in this document only for the purpose of completeness. BURT`s basic purpose is to back up sets of values so that they can be later restored. Each time a back up is requested, a new ASCII file is generated. Further, the data values are stored as ASCII strings and therefore not compressed. Both of these facts conspire against BURT as a candidate for an archiver. Users who need an archiver should use a different tool, the Archiver.

Effect of exhalation exercise on trunk muscle activity and oswestry disability index of patients with chronic low back pain

OpenAIRE

Kang, Jeong-Il; Jeong, Dae-Keun; Choi, Hyun

2016-01-01

[Purpose] This study investigated the effect of exhalation exercises on trunk muscle activity and Oswestry Disability Index by inducing trunk muscle activity through increasing intra-abdominal pressure and activating muscles, contributing to spinal stability. [Subjects and Methods] This intervention program included 20 male patients with chronic low back pain. A total of 10 subjects each were randomly assigned to an exhalation exercise group as the experimental group and a spinal stabilizatio...

Liquid radioactive waste processing system for pressurized water reactor plants

International Nuclear Information System (INIS)

Anon.

1976-01-01

This Standard sets forth design, construction, and performance requirements, with due consideration for operation, of the Liquid Radioactive Waste Processing System for pressurized water reactor plants for design basis inputs. For the purpose of this Standard, the Liquid Radioactive Waste Processing System begins at the interfaces with the reactor coolant pressure boundary and the interface valve(s) in lines from other systems, or at those sumps and floor drains provided for liquid waste with the potential of containing radioactive material; and it terminates at the point of controlled discharge to the environment, at the point of interface with the waste solidification system, and at the point of recycle back to storage for reuse

A method of Modelling and Simulating the Back-to-Back Modular Multilevel Converter HVDC Transmission System

Science.gov (United States)

Wang, Lei; Fan, Youping; Zhang, Dai; Ge, Mengxin; Zou, Xianbin; Li, Jingjiao

2017-09-01

This paper proposes a method to simulate a back-to-back modular multilevel converter (MMC) HVDC transmission system. In this paper we utilize an equivalent networks to simulate the dynamic power system. Moreover, to account for the performance of converter station, core components of model of the converter station gives a basic model of simulation. The proposed method is applied to an equivalent real power system.

Compound Half-Backed Weave Design For Digital Jacquard Fabric

Science.gov (United States)

Zhang, Meng; Zhou, Jiu

2017-12-01

Based on layered-combination design mode and compound structure, this paper presents a design method, named compound half-backed weave in order to achieve innovating weave structure and surface effect of fabric. This design method includes primary weaves chosen, half-backed technical points set up and half-backed weave databases established. The fabric produced using compound half-backed weave designed by this method can exhibit a unique half-backed effect that only half of the threads on the fabric surface remain in a state of being covered by adjacent wefts. Compound half-backed weave can not only meets the design need of jacquard fabric with different digital images and effectively improves the efficiency of structural design, but also puts forward new theory and method for innovative design of digital jacquard fabric.

[Rehabilitation for the patients with low-back pain].

Science.gov (United States)

Shirado, Osamu; Watanabe, Yasuyuki; Kawase, Masafumi

2005-03-01

The first choice for the treatment of low-back pain should be physical therapy, or rehabilitation. These are mainly divided into two modalities; passive and active modality. The former includes bed rest, hot pack, massage, and brace. The latter includes therapeutic exercise. The modality used should be dependent of the stages in each patient. Bed rest is indicated in the acute stage within a week after the occurrence low-back pain. The rest longer than a week is basically contraindicated, because of disuse syndrome such as muscle weakness, osteoporosis, and soft tissue contracture. Therapeutic exercise is the mainstay in the chronic stage. It includes trunk muscles strengthening exercise and stretching. Lumbar stabilization exercise has currently drawn attention for the treatment of low-back pain. Patient education such as back-school also plays an important role to manage low-back pain.

[Roof folding and rotary pushing for the treatment of back to back fractures of distal radius and ulna in children].

Science.gov (United States)

Xu, Ping; Dong, Xiao-jun; Lu, Zhou-tong; Wang, Gongjun; Zhang, Han-qing; Chen, Xuan-ning; Li, Dong

2015-09-01

To evaluate the technique and the clinical effect of folding roof and rotary pushing in treatment of children with distal radius and ulna fracture of "back to back". From January 2012 to February 2014,38 children with distal radius and ulna fracture of "back to back" were treated by using the technique of folding roof and rotary pushing to reset and splint fixation including 23 males and 15 females with an average age of 9.5 years old ranging from 6 to 14 years old. Injury time was from 45 min to 3 days (averaged 1.3 days). All cases was unilateral closed fracture without symptoms of nerve injury occurred. The wrist joint anteroposterior and lateral radiographs showed double fracture of radius and ulna, and the broken end of radius was typical "back to back" displacement. The quality of reduction was assessed according to Dienst recommendation on the combination of Aro measurement, and the therapeutic effect was evaluated using standard of Anderson function. All patients were followed up from 3 to 13 months with an average of 6 months. There were no iatrogenic nerve injury. Thirty cases were treated successfully for the first time, 8 cases were again reset successfully; 28 cases were anatomical reduction, 7 cases were near anatomic reduction, 3 cases were functional reduction. At the second day 7 cases with hand and finger swelling appeared in multiple reset patients. Quality results of reduction were excellent in 33 cases, good in 5 cases. According to the standard of Anderson function evaluation, 35 cases were excellent, 3 cases were good. All fractures were healed with of deformity of wrist. Using the technique of folding roof and rotary pushing in treatment of children with distal radius and ulna fracture of "back to back" is very successful, the patient's limb function recovered well, the whole operation process is simple.

A prospective randomized controlled study of VAX-D and TENS for the treatment of chronic low back pain.

Science.gov (United States)

Sherry, E; Kitchener, P; Smart, R

2001-10-01

Low back pain is one of the most significant medical and socioeconomic problems in modern society. International guidelines call for evidence-based management for the pain and disability associated with musculoskeletal disorders. The purpose of this randomized controlled trial is to address the question of efficacy and appropriateness of vertebral axial decompression (VAX-D) therapy, a new technology that has been shown in clinical research to create negative intradiscal pressures, and has been shown to be effective in treating patients presenting with chronic low back pain (> 3 months duration) with associated leg pain. Successful outcome was defined as a 50% reduction in pain utilizing a 10 cm Visual Analog Pain Scale and an improvement in the level of functioning as measured by patient-nominated disability ratings. Patients were randomly assigned to VAX-D or to TENS which was used as a control treatment or placebo. The TENS treatment demonstrated a success rate of 0%, while VAX-D demonstrated a success rate of 68.4% (p pain and improvement in functional outcome was obtained in patients with chronic low back pain treated with VAX-D.

Lumbar CT findings of patients with low back pain

International Nuclear Information System (INIS)

Lee, Yong Chul; Kim, Yang Soo; Kim, Kyun Sang

1986-01-01

Low back pain is probably the second most common disease entity to upper respiratory infection in developed country. We were missing at least 50% of the pathologic conditions by using conventional diagnostic modalities in low back pain. They did tell us nothing or little about facet abnormalities, lateral recesses, vertebral canal and soft tissue surrounding lumbar spines. High resolutional CT has been the biggest turning point in the diagnosis and management of low back pain. CT make a contribution to reducing the morbidity and probably the cost of evaluating patients with low back pain, and to increasing diagnostic accuracy. We observed 100 cases of lumbar CT using TCT 80A scanner for the evaluation of low back pain during the period from Apr. 1985 to Sept. 1985 at Chung-Ang University Hospital. Lumbar CT scan reveals high-positive findings (98%) in low back pain patients. Common low back disorders in CT are disc bulging (53%), herniated nucleus pulposus (32%), degenerative arthritis in posterior facet joints (27%), spinal stenosis (20%) and postoperative spines (15%). Uncommon low back disorders in CT are compression fracture of vertebral bodies, spondylolysis or spondylolisthesis, tropism, transitional vertebra, Scheueman's disease, limbic fracture, transverse process or articular process fracture, sacroiliac joint subluxation, conjoined nerve root and meningocele.

Lumbar CT findings of patients with low back pain

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Chul; Kim, Yang Soo; Kim, Kyun Sang [Chung-Ang University, Seoul (Korea, Republic of)

1986-04-15

Low back pain is probably the second most common disease entity to upper respiratory infection in developed country. We were missing at least 50% of the pathologic conditions by using conventional diagnostic modalities in low back pain. They did tell us nothing or little about facet abnormalities, lateral recesses, vertebral canal and soft tissue surrounding lumbar spines. High resolutional CT has been the biggest turning point in the diagnosis and management of low back pain. CT make a contribution to reducing the morbidity and probably the cost of evaluating patients with low back pain, and to increasing diagnostic accuracy. We observed 100 cases of lumbar CT using TCT 80A scanner for the evaluation of low back pain during the period from Apr. 1985 to Sept. 1985 at Chung-Ang University Hospital. Lumbar CT scan reveals high-positive findings (98%) in low back pain patients. Common low back disorders in CT are disc bulging (53%), herniated nucleus pulposus (32%), degenerative arthritis in posterior facet joints (27%), spinal stenosis (20%) and postoperative spines (15%). Uncommon low back disorders in CT are compression fracture of vertebral bodies, spondylolysis or spondylolisthesis, tropism, transitional vertebra, Scheueman's disease, limbic fracture, transverse process or articular process fracture, sacroiliac joint subluxation, conjoined nerve root and meningocele.

Persian Back Channel Responses in Formal versus Informal Contexts

Directory of Open Access Journals (Sweden)

Shahla Sharifi

2012-01-01

Full Text Available Utterances like /xob/ (okay, /doroste/ (right, /hmm/, /ee/, /?re/ (yeah, occur frequently in Persian conversations, but have thus far escaped from the systematic studies. Good listeners generally produce these short utterances, called "back channel responses", in appropriate times to show their participation in the conversation, but the rules governing back channeling vary from one context to another. The usage of back channel responses is different in various contexts, due to politeness or formality. This paper studies the types and functions of the back channel responses in both formal and informal settings and provides a comparison of the usage of these responses in these two kinds of contexts. The results show /bale/ (yes and /doroste/ (right are used with formal or polite verbal form, while /xob/ (okay is used with the informal style of speech and less polite verbal form. With respect to the function of back channels, signaling the understanding is the main function of back channels in informal contexts. Also, back channels signaling agreement are more frequent in formal contexts, where emotional function is less likely.

Do illness perceptions of people with chronic low back pain differ from people without chronic low back pain?

NARCIS (Netherlands)

van Wilgen, C. Paul; van Ittersum, Miriam W.; Kaptein, Ad A.

Objectives To determine why some people develop chronic low back pain, and whether illness perceptions are an important risk factor in the transition from acute to chronic low back pain. Design Cross-sectional study. Participants Four hundred and two members of the general Dutch population, with and

Get the Monkey off Your Back

Science.gov (United States)

Ciabattini, David; Custer, Timothy J.

2008-01-01

Monkeys are the problems that need solutions, the tasks that need to be accomplished, the decisions that need to be made, and the actions that need to be taken. According to a theory, people carry monkeys around on their backs until they can successfully shift their burden to someone else and the monkey leaps from one back to the next. Managers…

Non-steroidal anti-inflammatory drugs for chronic low back pain

NARCIS (Netherlands)

W.T.M. Enthoven (Wendy); P.D.D.M. Roelofs (Pepijn); R.A. Deyo (Richard); M.W. van Tulder (Maurits); B.W. Koes (Bart)

2016-01-01

textabstractBackground: Chronic back pain is an important health problem. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat people with low back pain, especially people with acute back pain. Short term NSAID use is also recommended for pain relief in people with chronic back

The effects of spinal support device on pain and extensibility of the hamstrings in patients with non-specific low back pain.

Science.gov (United States)

Jeon, Eun Tae; Jung, Jin-Hwa; Moon, Jong Hoon; Jung, Kyoung-Sim; Won, Young Sik; Kim, Sung-Jin; Hahm, Suk-Chan; Cho, Hwi-Young

2017-08-01

[Purpose] The objective of this study was to investigate the effects of spinal support device (SSD) on pain and hamstring extensibility in patients with non-specific low back pain (NSLBP). [Subjects and Methods] 20 patients with NSLBP were recruited and randomly assigned to either the SSD group or the control group. In the SSD group, SSD was applied; in the control group, bed rest in supine position was performed. Both groups underwent treatment 20 min/day, 3 times a week, for a duration of 4 weeks. To assess the hamstring extensibility, sit and reach test (SRT) was performed. To assess pain pressure threshold (PPT) of the sacroiliac joint, a pressure algometer was used. Visual analog scale (VAS) was used to quantify pain. [Results] The SSD group showed a significant improvement in sacroiliac joint pain with increased VAS, and the control group showed a significantly increased VAS after intervention. In the SSD group, VAS was significantly increased, but SRT was not changed compared with the control group. [Conclusion] These results demonstrated that an application of SSD effectively attenuates low back pain. Therefore, SSD may be a suitable intervention for pain control in patients with NSLBP.

Visual Impairment/Increased Intracranial Pressure (VIIP): Layman's Summary

Science.gov (United States)

Fogarty, Jennifer

2011-01-01

To date NASA has documented that seven long duration astronauts have experienced in-flight and post-flight changes in vision and eye anatomy including degraded distant vision, swelling of the back of the eye, and changes in the shape of the globe. We have also documented in a few of these astronauts post-flight, increases in the pressure of the fluid that surrounds the brain and spinal cord. This is referred to as increased intracranial pressure (ICP). The functional and anatomical changes have varied in severity and duration. In the post-flight time period, some individuals have experienced a return to a pre-flight level of visual function while others have experienced changes that remain significantly altered compared to pre-flight. In addition, the increased ICP also persists in the post-flight time period. Currently, the underlying cause or causes of these changes is/are unknown but the spaceflight community at NASA suspects that the shift of blood toward the head and the changes in physiology that accompany it, such as increased intracranial pressure, play a significant role.

Investigation into the Control Methods to Reduce the DC-Link Capacitor Ripple Current in a Back-to-Back Converter

DEFF Research Database (Denmark)

Qin, Zian; Wang, Huai; Blaabjerg, Frede

2014-01-01

Three-phase back-to-back converters have a wide range of applications (e.g. wind turbines) in which the reliability and cost-effectiveness are of great concern. Among other components and interconnections, DC-link capacitors are one of the weak links influenced by environmental stresses (e.......g. ambient temperature, humidity, etc.) and operating stresses (e.g. voltage, ripple current). This paper serves to investigate the ways of reducing ripple current stresses of DC-link capacitors in back-toback converters. The outcome could benefit to achieve either an extended lifetime for a designed DC...

Solidification with back-diffusion of irregular eutectics

Directory of Open Access Journals (Sweden)

M. Trepczyńska-Łent

2008-10-01

Full Text Available The definition of the α - parameter back-diffusion has been introduced in the work. The alternative models of solidification were describedtaking into consideration back-diffusion process. The possibility of using those models for eutectic alloys solidification is worthyof interest.

Lifetime prediction for organic coating under alternating hydrostatic pressure by artificial neural network

Science.gov (United States)

Tian, Wenliang; Meng, Fandi; Liu, Li; Li, Ying; Wang, Fuhui

2017-01-01

A concept for prediction of organic coatings, based on the alternating hydrostatic pressure (AHP) accelerated tests, has been presented. An AHP accelerated test with different pressure values has been employed to evaluate coating degradation. And a back-propagation artificial neural network (BP-ANN) has been established to predict the service property and the service lifetime of coatings. The pressure value (P), immersion time (t) and service property (impedance modulus |Z|) are utilized as the parameters of the network. The average accuracies of the predicted service property and immersion time by the established network are 98.6% and 84.8%, respectively. The combination of accelerated test and prediction method by BP-ANN is promising to evaluate and predict coating property used in deep sea. PMID:28094340

On calculating the pressure on cylindrical timbers of vertical shafts in clayey soils

Energy Technology Data Exchange (ETDEWEB)

Mizyumskii, V A

1979-11-01

In order to calculate the pressure built up on timbers which have been constructed to hold back freely moving soil in a clay environment, a formula is recommended which characterizes the state of clayey soil. The formula incorporates the parameters for volume information, momentary and long displacement modulus, decay factor of deformations of the after effect, viscosity factor in the starting zone of reforming. Because the timber creates a reaction pressure on the contour of the working, the radial travel of the timber is calculated and then the pressure on the timber. Correlation of the calculated pressure with the results of measurements in workings showed that the pressure of clayey soil on the timber is the result of viscous flow deformations. Disregarding these deformations, the pressures on the shaft timbering in the Yuzhno-Belozerskii deposit were calculated at 0.004 and 0.006 tons/m/sup 2/ respectively at a depth of 90 and 142 meters. After reworking the soil and setting up timbering the pressure was calculated at 2/3 of that of the highest measurements. The formula suggested is suitable for determining pressure on timbers having a large creep. (12 refs.) (In Russian)

Antidepressants for non-specific low back pain

NARCIS (Netherlands)

Urquhart, D. M.; Hoving, J. L.; Assendelft, W. W. J. J.; Roland, M.; van Tulder, M. W.

2008-01-01

BACKGROUND: Antidepressants are commonly used in the management of low-back pain. However, their use is controversial. OBJECTIVES: The aim of this review was to determine whether antidepressants are more effective than placebo for the treatment of non-specific low-back pain. SEARCH STRATEGY:

Space-time electrostatic probing of low-pressure discharge lamps during the early stages of electrical breakdown

NARCIS (Netherlands)

Gendre, M.F.; Bowden, M.D.; Haverlag, M.; Nieuwenhuizen, van den H.C.M.; Gielen, J.W.A.M.; Kroesen, G.M.W.

2005-01-01

The lime and space evolution of the electrostatic potential of a low-pressure lamp is investigated during ignition with a special capacitive probe. Observations show that ionisation waves propagate back and forth in the lamp, coinciding with the displacement of a local region of strong potential

Tunnel pressure waves - A smartphone inquiry on rail travel

Science.gov (United States)

Müller, Andreas; Hirth, Michael; Kuhn, Jochen

2016-02-01

When traveling by rail, you might have experienced the following phenomenon: The train enters a tunnel, and after some seconds a noticeable pressure change occurs, as perceived by your ears or even by a rapid wobbling of the train windows. The basic physics is that pressure waves created by the train travel down the tunnel, are reflected at its other end, and travel back until they meet the train again. Here we will show (i) how this effect can be well understood as a kind of large-scale outdoor case of a textbook paradigm, and (ii) how, e.g., a prediction of the tunnel length from the inside of a moving train on the basis of this model can be validated by means of a mobile phone measurement.

Nursery function of tropical back-reef systems

NARCIS (Netherlands)

Adams, A.J.; Dahlgren, C.P.; Kellison, G.T.; Kendall, M.S.; Layman, C.A.; Ley, J.A.; Nagelkerken, I.; Serafy, J.E.

2006-01-01

Similar to nearshore systems in temperate latitudes, the nursery paradigm for tropical back-reef systems is that they provide a habitat for juveniles of species that subsequently make ontogenetic shifts to adult populations on coral reefs (we refer to this as the nursery function of back-reef

[Pressure sores in a university hospital].

Science.gov (United States)

Barbut, Frédéric; Parzybut, Bérengère; Boëlle, Pierre-Yves; Neyme, Denis; Farid, Rachida; Kosmann, Marie-Jeanne; Luquel, Laurence

2006-05-01

To determine the prevalence of pressure sores, their risk factors, and the responsible microbial agents in an acute-care hospital and to evaluate their management. A prevalence survey was conducted from 5 July through 9 July 2004. Investigators completed a standardized questionnaire for each hospitalized patient, including demographic data (age, sex, previous hospitalizations, etc.) and Braden scale risk factors (sensory perception, humidity, activity, mobility, nutrition, and friction and shear). Two experts in skin care detected pressure sores by physical examination of the patients. Each pressure sore was swabbed and inoculated on selective media. Management was evaluated by reviewing the clinical charts of each patient with a pressure sore. The study included 535 adult patients (aged 59 +/- 19 years): 75 ulcer sores were observed in 37 patients (prevalence=6.9%). Stage I sores accounted for 24% of the total, stage II for 29%, stage III 31%, and stage IV 16%. The most frequent site was the heel (41%), followed by the sacrum (20%), elbow (11%), back (7%) and ischial tuberosities (7%). Sixty (80%) were acquired while hospitalized. Age-adjusted multivariate analyses found that the risk factors significantly associated with pressure sores were Braden scorepressure sores (OR=5.0 95% CI: 2.2-11.6, psores (24.5%), mostly stage III and IV, were colonized by multiple-drug-resistant bacteria (i.e., methicillin resistant Staphylococcus aureus, extended spectrum beta-lactamase Enterobacteriaceae). Seven (9.3%) of the 75 ulcers were diagnosed only during the survey, by the experts; of the 68 diagnosed before the survey, 57 (83.8%) had been under treatment. Treatment was considered inappropriate according to French guidelines in 31.6% of the cases. This prospective prevalence study resulted in better awareness of the patients at risk for pressure sores. It also made the recently created mobile geriatrics unit better known within the hospital.

Drain Back, Low Flow Solar Combi Systems

DEFF Research Database (Denmark)

Perers, Bengt; Furbo, Simon; Fan, Jianhua

2014-01-01

Drain Back systems with ETC collectors are tested and analyzed in a Danish - Chinese cooperation project. Experiences from early work at DTU, with drain back, low flow systems, was used to design two systems: 1) One laboratory system at DTU and 2) One demonstration system in a single family house...... in Sorö Denmark. Detailed monitoring and modelling of the system in the DTU lab is done to be able to generalize the results, to other climates and loads and to make design optimizations. The advantage with drain back, low flow systems, is that the system can be made more simple with less components...... and that the performance can be enhanced. A combination of the drain back- and system expansion vessel was tested successfully. Small initial problems with installation and proposals for design improvements to avoid these in practice are described in the paper. Installer education and training is an important step to have...

Adolescent low back pain among secondary school students in ...

African Journals Online (AJOL)

Adolescent low back pain among secondary school students in Ibadan, Nigeria. BOA Adegoke, AC Odole, AA Adeyinka. Abstract. Background: Adolescent low back pain (ALBP) can be considered a signal or precursor of a serious organic disease or telltale sign of future incidence of low back pain in adulthood. Published ...

Fluorinated tin oxide back contact for AZTSSe photovoltaic devices

Energy Technology Data Exchange (ETDEWEB)

Gershon, Talia S.; Gunawan, Oki; Haight, Richard A.; Lee, Yun Seog

2017-03-28

A photovoltaic device includes a substrate, a back contact comprising a stable low-work function material, a photovoltaic absorber material layer comprising Ag.sub.2ZnSn(S,Se).sub.4 (AZTSSe) on a side of the back contact opposite the substrate, wherein the back contact forms an Ohmic contact with the photovoltaic absorber material layer, a buffer layer or Schottky contact layer on a side of the absorber layer opposite the back contact, and a top electrode on a side of the buffer layer opposite the absorber layer.

specific low back pain

African Journals Online (AJOL)

2015-09-01

Sep 1, 2015 ... SPECIFIC LOW BACK PAIN: IMPLICATION FOR DIRECT HEALTH. CARE COST ... abundant evidence suggesting the benefits of therapeu- tic exercise on pain and ... Exercise and behavioural therapies in chronic pain. 174.

Comparison of Cardiorespiratory fitness of Nigerians with Low back ...

African Journals Online (AJOL)

The objective of this study was to compare Cardiorespiratory fitness (CRF) of Nigerians with low back pain (LBP) and apparently healthy counterparts. A total of Seventy (70) subjects participated in the study; 35 of them were low back pain patients, while the remaining 35 were apparently healthy adults. For low back pain ...

Back pain in ophthalmology: National survey of Indian ophthalmologists

Directory of Open Access Journals (Sweden)

Ramesh Venkatesh

2017-01-01

Full Text Available Purpose: The aim is to assess the prevalence, severity, and associations of back pain among Indian ophthalmologists. Methods: A self-reporting questionnaire was sent to ophthalmologists with valid e-mail addresses registered with the All India Ophthalmological Society. The survey was open for responses for 2 months. Results: A total of 651 (5.96% responses were obtained; 394 (61% males and 257 (39% females. Half (50% of responses were obtained from doctors belonging to 31–40 years' age group. Two hundred and thirty (35% of the ophthalmologists had height ranging from 161 to 170 cm and 443 (68% had weight ranging from 51 to 75 kg. Four hundred and eighty-one (73.8% of the respondents had <15 years of ophthalmic experience. Cataract (346; 53.1% and general ophthalmology (342; 52.5% were commonly practised by the ophthalmologists. Time spent in the outpatient department (OPD was 39.37 ± 16.32 h/week and in the operating theater 13.64 ± 9.89 h/week, respectively. Self-reported prevalence of back pain was 70.5%. Fully 49% of respondents had low back pain, followed by neck pain (33% and upper extremity symptoms (16%. Age <50 years (odds ratio [OR] = 2.4485, female gender (OR = 2.0265, long working hours in OPD (OR = 1.6524, and performing retinal lasers and indirect ophthalmoscopy (OR = 3.3251 showed positive association with back pain. The intolerable back pain was noted in <7% of the respondents. Around 398 (61% respondents felt that their back pain was exacerbated while doing work and 86.6% felt that up to 5 h/week was lost due to persistent backache. Yoga and some form of exercise (74.3% was practised to alleviate back pain. Conclusion: Back pain symptoms appear to be common among ophthalmologists. Awkward posture and prolonged working hours are responsible for developing back pain among ophthalmologists. Performing yoga and regular exercises, modifications in instrumentation and creating a larger workforce of eye care practitioners are needed

Acknowledging the patient with back pain

DEFF Research Database (Denmark)

Damsgaard, Janne Brammer; Jørgensen, Lene Bastrup; Norlyk, Annelise

2015-01-01

Rationale and aims: Research shows that back patients’ illness experiences affect their interaction with the healthcare system. It is important to examine the exact nature of these experiences in order to shed valuable light on how back patients perceive their illness and hospitalisation. The aim...... and translates into a certain way of perceiving and explaining illnesses and symptoms. Results: The thematic analysis shows that it is through experiences and memories that we create our identity and consciousness. Ignoring the illness experiences can therefore be seen as disregarding, the patient as a human...... of the included studies demonstrates the need for healthcare professionals to pay attention to back patients’ narratives in order to acknowledge them as human beings. This acknowledgement involves an ethical dimension and a sense of responsibility, manifested as respectful inclusion of the patient’s experiences...

NFP Investor Conference. Growth is back in sight.

Science.gov (United States)

Haugh, Richard

2002-06-01

In a whirlwind of high-stakes meetings in New York City in mid-May, two dozen of the nation's largest hospitals and health systems strutted their stuff with a single goal: securing their future. Their message was clear: back-to-basics works, and now it's time to grow the business. Executives from 23 providers outlined their work on increasing revenue, boosting margins and shoring up balance sheets. They presented their market positions, strategic initiatives and financial results for investment analysts, credit raters and bond traders. The third annual Non-Profit Healthcare Investor Conference was co-sponsored by the American Hospital Association, Health Forum, the Healthcare Financial Management Association and Salomon Smith Barney. The focus on growth doesn't come without challenges Several common themes emerged from the presentations, among them pressure on reimbursement, workforce shortages, liability insurance issues and capacity constraints. Yet executives agree: it all comes down to the basics, and building the strength to keep their missions alive. As Thomas Meier, vice president and treasurer of Oakland, Calif.-based Kaiser Permanente, put it: "No margin, no mission, no más."

Policy in France regarding the back-end of the fuel cycle reprocessing/recycling route

International Nuclear Information System (INIS)

Gloaguen, A.; Lenail, B.

1991-01-01

The decision taken in early 1970s to base the French power policy on the use of pressurized water reactors also included the strategy for the back end of the nuclear fuel cycle based on reprocessing, waste conditioning for the final disposal in the most suitable form in terms of safety and plutonium recycling to fast breeder reactors. Twenty years have elapsed, and substantial development and investment have been made. New evidences have emerged especially regarding breeder development, and the initial choice has been proved to be sound. EDF and COGEMA, the French utility and fuel cycle companies, respectively, are working together in order to take the best advantage of past efforts. The good behavior of MOX fuel in EDF reactors and the excellent start of the UP3 reprocessing plant of La Hague, which was completed and commissioned in August, 1990, made EDF and COGEMA extremely confident for future decision. The French choice made in favor of fuel reprocessing the history of fuel reprocessing in France, the policy concerning the back end of nuclear fuel cycle of EDF, and the present consideration and circumstances on this matter are reported. (K.I.)

A reliable approach to the closure of large acquired midline defects of the back

International Nuclear Information System (INIS)

Casas, L.A.; Lewis, V.L. Jr.

1989-01-01

A systematic regionalized approach for the reconstruction of acquired thoracic and lumbar midline defects of the back is described. Twenty-three patients with wounds resulting from pressure necrosis, radiation injury, and postoperative wound infection and dehiscence were successfully reconstructed. The latissimus dorsi, trapezius, gluteus maximus, and paraspinous muscles are utilized individually or in combination as advancement, rotation, island, unipedicle, turnover, or bipedicle flaps. All flaps are designed so that their vascular pedicles are out of the field of injury. After thorough debridement, large, deep wounds are closed with two layers of muscle, while smaller, more superficial wounds are reconstructed with one layer. The trapezius muscle is utilized in the high thoracic area for the deep wound layer, while the paraspinous muscle is used for this layer in the thoracic and lumbar regions. Superficial layer and small wounds in the high thoracic area are reconstructed with either latissimus dorsi or trapezius muscle. Corresponding wounds in the thoracic and lumbar areas are closed with latissimus dorsi muscle alone or in combination with gluteus maximus muscle. The rationale for systematic regionalized reconstruction of acquired midline back wounds is described

Finite element analysis of large elasto-plastic deformation for sealing ring in nuclear pressure vessel

International Nuclear Information System (INIS)

Xiao Xuejian; Chen Ruxin

1995-02-01

Based on the R. Hills incremental virtual power principle and the elasto-plastic constitution equation for large deformation and by considering physical nonlinear, geometric nonlinear and thermal effects, a plane and axisymmetric finite element equation for thermal large elasto-plastic deformation has been established in the Euler description. The corresponding analysis program ATLEPD has been also complied for thermal large elasto-plastic deformation process of O-ring in RPV. The variations of stress, strain, contact specific pressure, mesh deformation and the aspects of spring back in upsetting and spring back process have been also investigated. Numerical results are fairly consistent with experimental ones. (5 figs., 4 tabs.)

Control and simulation of fault and change effect in a back to back system of high voltage direct current network

International Nuclear Information System (INIS)

Mohsen, Kalantar; Mehdi, Rashidi; Mehdi, Rashidi; Tabatabaei, Naser M.

2005-01-01

Full text : The primary knowledge of human being from electrical energy was in the form of statistic electricity and the first transmission line was DC. But because of primary problems in transmitting electrical power in DC form with average and low voltage levels and because of the higher efficiency of AC machines in comparison with DC machines and presence of AC transistors in different capacitance, have caused the electrical power to be transmitted in AC form. But with the avancement of electrical engineering technology in the 20th century, the transition systems were used in HVDC form, and from that time the HDVC technology passed its improvement process so fast. In this paper in addition to discussing the advantage of HDVC systems and back to back instruction, the fault and change effect in a back to back system is discussed

Physical activity associate low back pain and intervention program: Review

Science.gov (United States)

Ibrahim, Muhamad Aizat Mat; Hasbollah, Hasif Rafidee; Ibrahim, Mohd Asrul Hery; Marican, Nor Dalila; Halim, Muhd Hafzal Abdul; Rashid, Ahmad Faezi Ab.; Yasin, Nurul Hafizah Mohd

2017-10-01

The person who have low back pain often report impaired disability to performance daily activities which passive movement of daily life. The effects of low back pain on daily function of patients can describe as a patients level of disability or reduction in physical function it interferes with the movement of patients for running a daily lives. Therefore, the aim of this study was to conduct a review to examine the relationship between physical activity and low back pain. Besides that, the suggestion prevention program to patient who has low back pain. This systematic review study was used internet to find databases and search engines. Data were collected using Wiley online library, Bioline International, SAGE, Science Direct, NCBI, ProQuest, Biomed central, American Diabetes Association, PLOS One and Springer. The search was performed using keywords of "physical activity", "low back pain", "back pain", "activity level" and "intervention". The study was reviewed the resources and the results were classified in different section The results were classified based on several sections including years of reporting, who were reporting, the origins of articles and their health criteria about physical activity and low back pain. There are positive associate physical activity and low back pain from the systematic review. Future intervention treatment can reduce associate physical activity to low back pain.

Super-virtual Interferometric Separation and Enhancement of Back-scattered Surface Waves

KAUST Repository

Guo, Bowen

2015-08-19

Back-scattered surface waves can be migrated to detect near-surface reflectors with steep dips. A robust surface-wave migration requires the prior separation of the back-scattered surface-wave events from the data. This separation is often difficult to implement because the back-scattered surface waves are masked by the incident surface waves. We mitigate this problem by using a super-virtual interferometric method to enhance and separate the back-scattered surface waves. The key idea is to calculate the virtual back-scattered surface waves by stacking the resulting virtual correlated and convolved traces associated with the incident and back-scattered waves. Stacking the virtual back-scattered surface waves improves their signal-to-noise ratio and separates the back-scattered surface-waves from the incident field. Both synthetic and field data results validate the robustness of this method.

Orbitofrontal cortex contribution to working memory. N-back ERP study

International Nuclear Information System (INIS)

Nakao, Yoshiaki; Tamura, Toshiyo; Kodabashi, Atsushi; Fujimoto, Toshiro; Yarita, Masaru

2011-01-01

Remarkable progress in cognitive neuroscience has revealed the involvement of the prefrontal cortex and the orbitofrontal cortex in human working memory, but the orbitofrontal cortex is still one of the least understood regions in the human brain. To elucidate the contribution of the orbitofrontal cortex to human working memory, we studied electroencephalography (EEG) P300 activity in n-back task. We elicited early P3 around 300 ms and late P3 around 360 ms of P300 components in n-back event related potentials (ERP). The amplitudes of the respective peaks changed depending on the working memory load (0-back, 1-back, 2-back, 3-back). We used source analysis to evaluate the orbitofrontal cortex in P3 components. A source model was constructed with the sources seeded from fMRI meta-analysis of n-back task and additional sources in the orbitofrontal cortex and the visual cortex estimated with P100 and late P3 components in the n-back ERP. This source model had more than 99% of GOF (goodness of fit) in n-back ERP. It gave us an insight of brain activity at the positions where sources existed. Early P3 was mainly produced by the dorsolateral prefrontal cortex, the ventrolateral prefrontal cortex, the inferior parietal lobule, the medial posterior parietal and the visual cortex. Late P3 was mainly produced by the medial premotor, the lateral premotor, the frontal pole and the orbitofrontal cortex. The contribution of the frontal pole and the orbitofrontal cortex had peaks around 390 ms which were later than late P3 component. In this study, the method to evaluate the orbitofrontal cortex activity in n-back ERP was provided. Our results elicited the involvement of the orbitofrontal cortex in late P3 component of n-back ERP. (author)

Disappearance of back-to-back high-pT hadron correlations in central Au+Au collisions at sqrt[s NN ] =200 GeV.

Science.gov (United States)

Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Corral, M M; Cramer, J G; Crawford, H J; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Magestro, D; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

2003-02-28

Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

Concordant pressure paresthesia during interlaminar lumbar epidural steroid injections correlates with pain relief in patients with unilateral radicular pain.

Science.gov (United States)

Candido, Kenneth D; Rana, Maunak V; Sauer, Ruben; Chupatanakul, Lalida; Tharian, Antony; Vasic, Vladimir; Knezevic, Nebojsa Nick

2013-01-01

Transforaminal and interlaminar epidural steroid injections are commonly used interventional pain management procedures in the treatment of radicular low back pain. Even though several studies have shown that transforaminal injections provide enhanced short-term outcomes in patients with radicular and low back pain, they have also been associated with a higher incidence of unintentional intravascular injection and often dire consequences than have interlaminar injections. We compared 2 different approaches, midline and lateral parasagittal, of lumbar interlaminar epidural steroid injection (LESI) in patients with unilateral lumbosacral radiculopathic pain. We also tested the role of concordant pressure paresthesia occurring during LESI as a prognostic factor in determining the efficacy of LESI. Prospective, randomized, blinded study. Pain management center, part of a teaching-community hospital in a major metropolitan US city. After Institutional Review Board approval, 106 patients undergoing LESI for radicular low back pain were randomly assigned to one of 2 groups (53 patients each) based on approach: midline interlaminar (MIL) and lateral parasagittal interlaminar (PIL). Patients were asked to grade any pressure paresthesia as occurring ipsilaterally or contralaterally to their "usual and customary pain," or in a distribution atypical of their daily pain. Other variables such as: the Oswestry Disability Index questionnaire, pain scores at rest and during movement, use of pain medications, etc. were recorded 20 minutes before the procedure, and on days 1, 7, 14, 21, 28, 60, 120, 180 and 365 after the injection. Results of this study showed statistically and clinically significant pain relief in patients undergoing LESI by both the MIL and PIL approaches. Patients receiving LESI using the lateral parasagittal approach had statistically and clinically longer pain relief then patients receiving LESI via a midline approach. They also had slightly better quality of

A longitudinal assessment of myoelectric activity, postural sway, and low-back pain during pregnancy.

Science.gov (United States)

Moreira, Luciana S; Elias, Leonardo A; Gomide, Adriane B; Vieira, Marcus F; DO Amaral, Waldemar N

2017-01-01

The present study aimed at investigating the control of upright quiet standing in pregnant women throughout pregnancy, and whether low-back pain exerts influence on this motor task. Myoelectric signals from postural muscles and stabilometric data were collected from 15 non-pregnant and 15 pregnant women during upright quiet standing. Electromyogram envelopes and center of pressure metrics were evaluated in the control group, as well as in pregnant women in their first and third trimester of pregnancy. A correlation analysis was performed between the measured variables and a low-back pain disability index. Pregnant women exhibited a decreased maximum voluntary isometric activity for all postural muscles evaluated. Additionally, the activity of lumbar muscles during the postural task was significantly higher in the pregnant women in comparison to the non-pregnant controls. The soleus muscle maintained its activity at the same level as the gestation progressed. Higher postural oscillations were observed in the anteroposterior direction while mediolateral sway was reduced in the third trimester of pregnancy. No correlation was detected between the lowback pain disability index and neuromechanical variables. This study provides additional data regarding the functioning and adaptations of the postural control system during pregnancy. Also, we provide further evidence that postural control during quiet standing cannot be used to predict the occurrence of low-back pain. We hypothesize that the modifications in the neural drive to the muscles, as well as in postural sway may be related to changes in the biomechanics and hormonal levels experienced by the pregnant women.

Back schools for the treatment of chronic low back pain: possibility of benefit but no convincing evidence after 47 years of research-systematic review and meta-analysis.

Science.gov (United States)

Straube, Sebastian; Harden, Markus; Schröder, Heiko; Arendacka, Barbora; Fan, Xiangning; Moore, R Andrew; Friede, Tim

2016-10-01

Back schools are interventions that comprise exercise and education components. We aimed to systematically review the randomized controlled trial evidence on back schools for the treatment of chronic low back pain. By searching MEDLINE, Embase, and Cochrane Central as well as bibliographies, we identified 31 studies for inclusion in our systematic review and 5 of these for inclusion in meta-analyses. Meta-analyses for pain scores and functional outcomes revealed statistical superiority of back schools vs no intervention for some comparisons but not others. No meta-analysis was feasible for the comparison of back schools vs other active treatments. Adverse events were poorly reported so that no reliable conclusions regarding the safety of back schools can be drawn, although some limited reassurance in this regard may be derived from the fact that few adverse events and no serious adverse events were reported in the back school groups in the studies that did report on safety. Overall, the evidence base for the use of back schools to treat chronic low back pain is weak; in nearly a half-century since back schools were first trialled, no unequivocal evidence of benefit has emerged.

Back schools for the treatment of chronic low back pain: possibility of benefit but no convincing evidence after 47 years of research—systematic review and meta-analysis

Science.gov (United States)

Straube, Sebastian; Harden, Markus; Schröder, Heiko; Arendacka, Barbora; Fan, Xiangning; Moore, R. Andrew; Friede, Tim

2016-01-01

Abstract Back schools are interventions that comprise exercise and education components. We aimed to systematically review the randomized controlled trial evidence on back schools for the treatment of chronic low back pain. By searching MEDLINE, Embase, and Cochrane Central as well as bibliographies, we identified 31 studies for inclusion in our systematic review and 5 of these for inclusion in meta-analyses. Meta-analyses for pain scores and functional outcomes revealed statistical superiority of back schools vs no intervention for some comparisons but not others. No meta-analysis was feasible for the comparison of back schools vs other active treatments. Adverse events were poorly reported so that no reliable conclusions regarding the safety of back schools can be drawn, although some limited reassurance in this regard may be derived from the fact that few adverse events and no serious adverse events were reported in the back school groups in the studies that did report on safety. Overall, the evidence base for the use of back schools to treat chronic low back pain is weak; in nearly a half-century since back schools were first trialled, no unequivocal evidence of benefit has emerged. PMID:27257858

Lower Back Tattoo: OK to Have an Epidural?

Science.gov (United States)

... and delivery, postpartum care Could a lower back tattoo keep me from having an epidural during labor? ... Yvonne Butler Tobah, M.D. A lower back tattoo won't necessarily prevent you from having an ...

Cavitation and primary atomization in real injectors at low injection pressure condition

Science.gov (United States)

Dumouchel, Christophe; Leboucher, Nicolas; Lisiecki, Denis

2013-06-01

This experimental work investigates the influence of the geometry of GDI devices on primary atomization processes under low injection pressure and reduced back pressure. These pressure conditions ensure cavitating flows and observable atomization processes. Measurements include mass flux, structure velocity from high-speed visualizations and spray characterization with a laser diffraction technique. Super-cavitation regime and cavitation string, which have their own influence on the mass flux, develop independently in different injector regions. These regimes impact the flow pattern in the orifice and the subsequent atomization process. A possible interaction between cavitation string and super-cavitation is found to promote a hydraulic-flip-like regime and to deteriorate atomization quality. As far as the geometry of the injector is concerned, the profile of the orifice inlet and the roughness of the sac volume region are found to be important geometrical characteristics.

A systematic review on the effectiveness of back protectors for motorcyclists.

Science.gov (United States)

Ekmejian, Rafael; Sarrami, Pooria; Naylor, Justine M; Harris, Ian A

2016-10-04

Motorcyclists are a vulnerable road-user population who are overrepresented in traffic injuries. Utilisation of back protectors may be an effective preventive measure for spine injuries in motorcyclists. Since use of back protectors is increasing it is important that clinical evidence supports their use. The study aimed to investigate the current evidence on the ability of back protectors to reduce the rate of back injuries and patient mortality in motorcycle crashes. A systematic literature search was conducted using various electronic databases. Systematic reviews, randomised controlled trials, controlled clinical trials, cohort studies, case series and case reports were included Opinion pieces and laboratory or biomechanical studies were excluded. Back protectors and spine protectors were included as the intervention; neck braces and speed humps were excluded. The target outcomes were any injuries to the back or death. Only English language studies were included. The search strategy yielded 185 studies. After excluding 183 papers by title and abstract and full-text evaluation, only two small cross-sectional studies were included. Foam inserts in motorcycle jackets and non-standard clothing may possibly be associated with higher risk of injuries, while hard shell and standard back protectors may possibly be associated with a reduced rate of back and spinal injury. This systematic review highlighted lack of appropriate evidence on efficacy of back protectors. Based on limited information, we are uncertain about the effects of back protectors on spinal injuries. Further research is required to substantiate the effects of back protectors on mortality and other injuries to the back.

The influence of previous low back trouble, general health, and working conditions on future sick-listing because of low back trouble. A 15-year follow-up study of risk indicators for self-reported sick-listing caused by low back trouble.

Science.gov (United States)

Müller, C F; Monrad, T; Biering-Sørensen, F; Darre, E; Deis, A; Kryger, P

1999-08-01

A 15-year follow-up study. To find risk indicators for self-reported sick-listing because of low back trouble and to evaluate which variables were the most important indicators of work incapacity resulting from low back trouble during the follow-up period of 15 years. The initial data were obtained from a health survey conducted in a general population from the Municipality of Glostrup, Denmark. The follow-up data included information from the Central Person Register, the Early Retirement Pension Register, and a postal questionnaire regarding self-reported sick-listing because of low back trouble. An epidemiologic study, in which logistic regression analyses were used for evaluation of the data. The model used consisted of the variable in question, age, gender, and previous experience of low back trouble, along with interactions. It was found that 22 of 37 variables were risk indicators for later self-reported sick-listing because of low back trouble during the preceding year or the 7 years before the date of follow-up evaluation. In analyzing the most significant variables simultaneously, it was found that information from the initial investigation about sick-listing in general during the previous 10 years, sciatic pain, use of analgesics for low back trouble, previous sick-listing because of low back trouble, and occupation were the most important risk indicators for self-reported work incapacity resulting from low back trouble during the follow-up period of 15 years. Findings showed that the strongest prognostic indicators of later sick-listing because of low back trouble involve information from the person about previous sick-listing behavior in general and previous experience of low back trouble episodes, especially if these had been accompanied by sciatic pain, use of analgesics, or previous low back trouble sick-listing.

Optimal back-to-front airplane boarding

Science.gov (United States)

Bachmat, Eitan; Khachaturov, Vassilii; Kuperman, Ran

2013-06-01

The problem of finding an optimal back-to-front airplane boarding policy is explored, using a mathematical model that is related to the 1+1 polynuclear growth model with concave boundary conditions and to causal sets in gravity. We study all airplane configurations and boarding group sizes. Optimal boarding policies for various airplane configurations are presented. Detailed calculations are provided along with simulations that support the main conclusions of the theory. We show that the effectiveness of back-to-front policies undergoes a phase transition when passing from lightly congested airplanes to heavily congested airplanes. The phase transition also affects the nature of the optimal or near-optimal policies. Under what we consider to be realistic conditions, optimal back-to-front policies lead to a modest 8-12% improvement in boarding time over random (no policy) boarding, using two boarding groups. Having more than two groups is not effective.

Optimal back-to-front airplane boarding.

Science.gov (United States)

Bachmat, Eitan; Khachaturov, Vassilii; Kuperman, Ran

2013-06-01

The problem of finding an optimal back-to-front airplane boarding policy is explored, using a mathematical model that is related to the 1+1 polynuclear growth model with concave boundary conditions and to causal sets in gravity. We study all airplane configurations and boarding group sizes. Optimal boarding policies for various airplane configurations are presented. Detailed calculations are provided along with simulations that support the main conclusions of the theory. We show that the effectiveness of back-to-front policies undergoes a phase transition when passing from lightly congested airplanes to heavily congested airplanes. The phase transition also affects the nature of the optimal or near-optimal policies. Under what we consider to be realistic conditions, optimal back-to-front policies lead to a modest 8-12% improvement in boarding time over random (no policy) boarding, using two boarding groups. Having more than two groups is not effective.

Systematic review of conservative interventions for subacute low back pain.

Science.gov (United States)

Pengel, Heloise M; Maher, Chris G; Refshauge, Kathryn M

2002-12-01

To evaluate the effect of conservative interventions on clinically relevant outcome measures for patients with subacute low back pain. This is particularly important because effective treatment for subacute low back pain will prevent the transition to chronic low back pain, a condition that is largely responsible for the high health care costs of low back pain. Systematic review of randomized controlled trials. Methodological quality of each trial was assessed. Effect sizes and 95% confidence intervals were calculated for pain and disability and risk ratios for return to work. Thirteen trials were located, evaluating the following interventions: manipulation, back school, exercise, advice, transcutaneous electrical nerve stimulation (TENS), hydrotherapy, massage, corset, cognitive behavioural treatment and co-ordination of primary health care. Most studies were of low quality and did not show a statistically significant effect of intervention. For the strict duration of low back pain (six weeks to three months), no evidence of high internal validity was found but when other methodological criteria were considered, evidence was found for the efficacy of advice. Furthermore, there is evidence that when a broader view is taken of the duration of subacute low back pain (seven days to six months), other treatments (e.g. manipulation, exercise, TENS) may be effective. Our review identified a major gap in the evidence for interventions that are currently recommended in clinical practice guidelines for the treatment of subacute low back pain. Lack of a uniform definition of subacute low back pain further limited current evidence.

Meta-analysis: exercise therapy for nonspecific low back pain.

Science.gov (United States)

Hayden, Jill A; van Tulder, Maurits W; Malmivaara, Antti V; Koes, Bart W

2005-05-03

Exercise therapy is widely used as an intervention in low back pain. To evaluate the effectiveness of exercise therapy in adult nonspecific acute, subacute, and chronic low back pain versus no treatment and other conservative treatments. MEDLINE, EMBASE, PsychInfo, CINAHL, and Cochrane Library databases to October 2004; citation searches and bibliographic reviews of previous systematic reviews. Randomized, controlled trials evaluating exercise therapy for adult nonspecific low back pain and measuring pain, function, return to work or absenteeism, and global improvement outcomes. Two reviewers independently selected studies and extracted data on study characteristics, quality, and outcomes at short-, intermediate-, and long-term follow-up. 61 randomized, controlled trials (6390 participants) met inclusion criteria: acute (11 trials), subacute (6 trials), and chronic (43 trials) low back pain (1 trial was unclear). Evidence suggests that exercise therapy is effective in chronic back pain relative to comparisons at all follow-up periods. Pooled mean improvement (of 100 points) was 7.3 points (95% CI, 3.7 to 10.9 points) for pain and 2.5 points (CI, 1.0 to 3.9 points) for function at earliest follow-up. In studies investigating patients (people seeking care for back pain), mean improvement was 13.3 points (CI, 5.5 to 21.1 points) for pain and 6.9 points (CI, 2.2 to 11.7 points) for function, compared with studies where some participants had been recruited from a general population (for example, with advertisements). Some evidence suggests effectiveness of a graded-activity exercise program in subacute low back pain in occupational settings, although the evidence for other types of exercise therapy in other populations is inconsistent. In acute low back pain, exercise therapy and other programs were equally effective (pain, 0.03 point [CI, -1.3 to 1.4 points]). Limitations of the literature, including low-quality studies with heterogeneous outcome measures inconsistent

Back reaction of excitations on a vortex

Science.gov (United States)

Arodź, Henryk; Hadasz, Leszek

1997-01-01

Excitations of a vortex are usually considered in a linear approximation neglecting their back reaction on the vortex. In the present paper we investigate back reaction of Proca-type excitations on a straight linear vortex in the Abelian Higgs model. We propose an exact ansatz for fields of the excited vortex. From an initial set of six nonlinear field equations we obtain (in a limit of weak excitations) two linear wave equations for the back reaction corrections. Their approximate solutions are found in the cases of plane wave and wave-packet-type excitations. We find that the excited vortex radiates the vector field and that the Higgs field has a very broad oscillating component.

Suppression of back-to-back hadron pairs at forward rapidity in d+Au collisions at √s(NN)=200 GeV.

Science.gov (United States)

Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Angerami, A; Aoki, K; Apadula, N; Aramaki, Y; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, S; Caringi, A; Chen, C-H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Conesa del Valle, Z; Connors, M; Csanád, M; Csörgo, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; David, G; Dayananda, M K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; D'Orazio, L; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grim, G; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-Å; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ikeda, Y; Imai, K; Inaba, M; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Ivanischev, D; Iwanaga, Y; Jacak, B V; Jia, J; Jiang, X; Jin, J; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kamin, J; Kang, J H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, D J; Kim, E J; Kim, Y-J; Kinney, E; Kiss, Á; Kistenev, E; Kochenda, L; Komkov, B; Konno, M; Koster, J; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Leitch, M J; Leite, M A L; Li, X; Lichtenwalner, P; Liebing, P; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Miki, K; Milov, A; Mitchell, J T; Mohanty, A K; Moon, H J; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murakami, T; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Newby, J; Nguyen, M; Nihashi, M; Nouicer, R; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, S K; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Petti, R; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Qu, H; Rak, J; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Richardson, E; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rukoyatkin, P; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Samsonov, V; Sano, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Seto, R; Sharma, D; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Stenlund, E; Stoll, S P; Sugitate, T; Sukhanov, A; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Themann, H; Thomas, D; Thomas, T L; Togawa, M; Toia, A; Tomášek, L; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Wei, F; Wei, R; Wessels, J; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zhou, S; Zolin, L

2011-10-21

Back-to-back hadron pair yields in d+Au and p+p collisions at √s(NN)=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η|back-to-back hadron pairs in d+Au collisions with small impact parameters is observed to be suppressed by a factor of 10 relative to p+p collisions. The kinematics of these pairs is expected to probe partons in the Au nucleus with a low fraction x of the nucleon momenta, where the gluon densities rise sharply. The observed suppression as a function of nuclear thickness, p(T), and η points to cold nuclear matter effects arising at high parton densities. © 2011 American Physical Society

Pressure ulcer prevention and treatment: use of prophylactic dressings

Directory of Open Access Journals (Sweden)

Reid K

2016-10-01

Full Text Available Kathleen Reid,1 Elizabeth A Ayello,2 Afsaneh Alavi,3 1Department of Nursing Practice and Education, Bridgepoint Active Healthcare, Toronto, Canada; 2School of Nursing, Excelsior College, Albany, NY, USA; 3Department of Medicine, University of Toronto, Toronto, Canada Abstract: The management of pressure ulcers is challenging for health care providers across disciplines. Pressure ulcers have significant impact on emotional and physical wellbeing, quality of life, and health care costs. The use of wound dressings could be an important and cost-effective strategy in preventing pressure ulcers. The main types of dressings that are examined for this purpose in the literature are foam, hydrocolloid, and films. Some small studies have shown a preventative role for sacral dressings with low-shear backings, though they raise concerns about over-hydration of the skin. Further research demonstrates the application of barrier films over bony prominences to have a prophylactic effect; however, adhesive dressings can also contribute to shearing forces on the skin. There is a vast body of research that examines the use of dressings to prevent pressure ulcers; however, there is limited high-level evidence, such as randomized control trials. A 2013 Cochrane review indicated that there is a paucity of high-level evidence to support the prophylactic use of dressings to prevent pressure ulcers; this paper will examine the emerging literature and consider its relevance to pressure ulcer prevention protocols. Keywords: quality of life, hydrocolloid dressing, topical agent

Metal extrusion using hydrostatic pressures; Le filage des metaux sous pression hydrostatique

Energy Technology Data Exchange (ETDEWEB)

Sauve, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

The main problems connected with the deformation of metals due to extrusion are described. A method is put forward for calculating the rational rate of percentage deformation in the case of bar extrusion using a cylindrical container; reference is made to previous work on extrusion using a hydrostatic pressure with or without back-pressure. An extrusion process is described using hydrostatic pressure, without back-pressure, and using the lubricant for transmitting the thrust. This process has been used for eight years by the C.E.A. for the extrusion of a very wide range of metals, from beryllium to uranium and including steels; it leads to excellent surface textures. A very fine crystallization can be obtained on extruded products when the rate of extrusion is very low. There appears to be nothing against the use of high extrusion rates using this method. (author) [French] On expose les problemes generaux lies a la deformation des metaux par filage. On propose un calcul de la vitesse rationnelle de deformation pour cent dans le cas du filage de barres a partir d'un conteneur cylindrique, et l'on cite les travaux anterieurs sur le filage par faction d'une pression hydrostatique sans ou avec une contre-pression. On decrit un procede de filage par l'action d'une pression hydrostatique, sans contre-pression, utilisant le lubrifiant pour transmettre la poussee. Ce procede employe depuis 8 ans au C.E.A. pour filer les metaux les plus divers, depuis le beryllium jusqu'a l'uranium en passant par les aciers, permet d'obtenir d'excellents etats de surface. Une cristallisation tres fine peut etre obtenue sur les produits files lorsque le filage est tres lent. Rien ne parait s'opposer a ce que des filages rapides soient effectues avec cette methode. (auteur)

Back surgery: Modern medical pitfall.

Science.gov (United States)

Smith, Jc

2002-01-01

Medical iatrogenesis is at an all-time high with increasing deaths, disability, and costs compounded by unnecessary and ineffective surgeries despite the warnings from WHO, the US Public Health Service, and the Institute of Medicine. One area in particular, failed back surgeries, has drawn increasing attention by researchers due to disproved medical theories and surgical treatments. Paradoxically, while spinal manipulative therapy has been shown to achieve better results for this epidemic of low back pain in particular, medical and insurance programs often limit or boycott this inexpensive and effective treatment, indicating the solution to lowering medical costs and iatrogenesis now rests with political and economic factors primarily.

MEMS Fabry-Perot sensor interrogated by optical system-on-a-chip for simultaneous pressure and temperature sensing.

Science.gov (United States)

Pang, Cheng; Bae, Hyungdae; Gupta, Ashwani; Bryden, Kenneth; Yu, Miao

2013-09-23

We present a micro-electro-mechanical systems (MEMS) based Fabry-Perot (FP) sensor along with an optical system-on-a-chip (SOC) interrogator for simultaneous pressure and temperature sensing. The sensor employs a simple structure with an air-backed silicon membrane cross-axially bonded to a 45° polished optical fiber. This structure renders two cascaded FP cavities, enabling simultaneous pressure and temperature sensing in close proximity along the optical axis. The optical SOC consists of a broadband source, a MEMS FP tunable filter, a photodetector, and the supporting circuitry, serving as a miniature spectrometer for retrieving the two FP cavity lengths. Within the measured pressure and temperature ranges, experimental results demonstrate that the sensor exhibits a good linear response to external pressure and temperature changes.

Rehabilitation of low back pain patients. A review.

Science.gov (United States)

Revel, M

1995-01-01

Numerous methods have been developed for the rehabilitation of low back pain patients, including spinal flexion and extension exercises, lumbar spine locking in an intermediate position, enhancement of spinal and pelvic proprioceptive sensibility, swimming pool therapy, back schools, and functional restoration. Each seeks to achieve a goal assumed to be central to the prevention of a first or recurrent episode of low back pain. Goals include short-term pain relief, an improved ability to achieve self-sedation, abdominal and lumbar muscle strengthening, increased hip and lumbar spine mobility, improved lumbar and pelvic proprioceptive sensibility, intervertebral joint stabilization, lumbar posture modification and improved general fitness. Less than 30 studies meeting widely accepted validity and applicability criteria for therapeutic trials have addressed the clinical efficacy of rehabilitation in low back pain patients. Most studies of the back school approach have found no benefit. Spinal flexion and extension exercise programs have yielded short-lived improvements, with no differences across methods. There is evidence that functional restoration programs based on graded activity may provide long-term benefits including better social and occupational outcomes. We have evaluated the physical therapy methods most commonly taught to and used by physical therapists in France.

Low back pain during pregnancy and Kinesio tape application.

Science.gov (United States)

Reyhan, Aycan Çakmak; Dereli, Elif Elçin; Çolak, Tuğba Kuru

2017-01-01

Low back pain is a common problem during pregnancy. Although the pain usually occurs in the third trimester, it might be seen in the first trimester, too. There are various types of applications for the treatment of low back pain during pregnancy. However, there is a lack of evidence for the effectiveness of each method. If there is not an obvious deficit, bed rest, exercise, conventional physiotherapy, using protective principles for the lumbar area are recommended, since the main and the only complaint is low back pain. It is aimed in the current review to investigate the use of Kinesio tape in the low back pain seen during pregnancy and to review the literature related to this subject. There are only a few studies investigating the effect of Kinesio tape during pregnancy in the literature and they mostly did not aim to study the low back pain, further evidence and studies are needed to investigate the use of Kinesio tape for the low back pain seen during pregnancy as there is not evidence strong enough. Kinesiotape application aims to increase circulation and mobility, and regarding these gains decreased pain and increased performance are expected.

Limitations associated with managing chronic low back pain.

Science.gov (United States)

Beland, Paul

2016-04-20

Non-specific chronic low back pain is an occupational hazard for nurses. It may result in persistent and disabling pain for some people. There are many techniques for investigating, assessing and treating chronic low back pain. However, research to support some of these interventions and the assumptions that underlie them is limited. Interventions that may be beneficial are not always available to those who need them. Changes to service provision are required to rectify this situation and provide effective treatment for patients with non-specific chronic low back pain.

Back End Programming in .NET Framework

OpenAIRE

Sapkota, Dinesh

2013-01-01

The main goal of the project was to develop a web application which provides the services for both web and mobile client. The complete application development process was carried out by the team of four members and a supervisor. According to the interest of group members the whole project was divided into four parts; that is user interface design, mobile application development, back end development for mobile services and server side back end development of application. I got the task of ser...

Prolotherapy: An Effective Treatment for Low Back Pain?

Science.gov (United States)

... pain? Is prolotherapy an effective treatment for chronic low back pain? Answers from Brent A. Bauer, M.D. Prolotherapy is ... reduced pain. Studies of prolotherapy in people with low back pain have had mixed results. A combination of prolotherapy ...

Theeffectivenessofginger compress on non-specific low back pain ...

African Journals Online (AJOL)

Theeffectivenessofginger compress on non-specific low back pain. ... for a total of ten sessions and control group (n=7) did not received any treatment. ... in pain relief and reduces functional disability in patients with non-specific low back pain.

Pore closure in zeolitic imidazolate frameworks under mechanical pressure.

Science.gov (United States)

Henke, Sebastian; Wharmby, Michael T; Kieslich, Gregor; Hante, Inke; Schneemann, Andreas; Wu, Yue; Daisenberger, Dominik; Cheetham, Anthony K

2018-02-14

We investigate the pressure-dependent mechanical behaviour of the zeolitic imidazolate framework ZIF-4 (M(im) 2 ; M 2+ = Co 2+ or Zn 2+ , im - = imidazolate) with high pressure, synchrotron powder X-ray diffraction and mercury intrusion measurements. A displacive phase transition from a highly compressible open pore ( op ) phase with continuous porosity (space group Pbca , bulk modulus ∼1.4 GPa) to a closed pore ( cp ) phase with inaccessible porosity (space group P 2 1 / c , bulk modulus ∼3.3-4.9 GPa) is triggered by the application of mechanical pressure. Over the course of the transitions, both ZIF-4 materials contract by about 20% in volume. However, the threshold pressure, the reversibility and the immediate repeatability of the phase transition depend on the metal cation. ZIF-4(Zn) undergoes the op-cp phase transition at a hydrostatic mechanical pressure of only 28 MPa, while ZIF-4(Co) requires about 50 MPa to initiate the transition. Interestingly, ZIF-4(Co) fully returns to the op phase after decompression, whereas ZIF-4(Zn) remains in the cp phase after pressure release and requires subsequent heating to switch back to the op phase. These variations in high pressure behaviour can be rationalised on the basis of the different electron configurations of the respective M 2+ ions (3d 10 for Zn 2+ and 3d 7 for Co 2+ ). Our results present the first examples of op-cp phase transitions ( i.e. breathing transitions) of ZIFs driven by mechanical pressure and suggest potential applications of these functional materials as shock absorbers, nanodampers, or in mechanocalorics.

The Areva Group back-end division - challenges and prospects

International Nuclear Information System (INIS)

2004-06-01

This document presents the Areva Group back-end division challenges and prospects. Areva, a world nuclear industry leader, analyzes in this document, the high-profile mix of complementary activities of the nuclear energy industry, concerning the back-end division the full range of services for the end of the fuel cycle, the fuel cycle back-end markets, the economic and financial associated considerations. (A.L.B.)

Lombalgia ocupacional Occupational low back pain

Directory of Open Access Journals (Sweden)

Milton Helfenstein Junior

2010-01-01

Full Text Available A lombalgia ocupacional apresenta etiologia multifatorial, elevada prevalência e incidência. Caracterizada por quadro de dor de variada duração e intensidade, a dor lombar pode levar à incapacidade laborativa e à invalidez. A lombalgia acarreta sofrimento aos trabalhadores, custos às empresas, aos sistemas previdenciário e assistencial de saúde. Os autores, pela relevância do tema, elaboraram este artigo de revisão bibliográfica dando ênfase ao embasamento teorico-conceitual e à experiência de especialistas.The occupational low back pain presents multifactorial aetiology, important prevalence and incidence. Characterized by pain of varying duration and intensity, low back pain may lead to disability. Low back pain causes suffering to workers, implies costs to companies, to the social security and health assistance system. Because of the theme's relevance, the authors have elaborated this review of literature with emphasis on a theoretical and conceptual basis, as well as experience of experts.

Differences in lumbopelvic control and occupational behaviours in female nurses with and without a recent history of low back pain due to back injury.

Science.gov (United States)

Babiolakis, Corinne S; Kuk, Jennifer L; Drake, Janessa D M

2015-01-01

Low back pain is highly prevalent in nurses. This study aimed to determine which physical fitness, physical activity (PA) and biomechanical characteristics most clearly distinguish between nurses with [recently injured (RInj)] and without [not recently injured (NRInj)] a recent back injury. Twenty-seven (8 RInj, 19 NRInj) female nurses completed questionnaires (pain, work, PA), physical fitness, biomechanical and low back discomfort measures, and wore an accelerometer for one work shift. Relative to NRInj nurses, RInj nurses exhibited reduced lumbopelvic control (41.4% more displayed a moderate loss of frontal plane position), less active occupational behaviours (less moderate PA; less patient lifts performed alone; more sitting and less standing time) and more than two times higher low back discomfort scores. Despite no physical fitness differences, the lumbopelvic control, occupational behaviours and discomfort measures differed between nurses with and without recent back injuries. It is unclear whether poor lumbopelvic control is causal or adaptive in RInj nurses and may require further investigation. Practitioner Summary: It is unclear which personal modifiable factors are most clearly associated with low back pain in nurses. Lumbopelvic control was the only performance-based measure to distinguish between nurses with and without recent back injuries. Future research may investigate whether reduced lumbopelvic control is causal or adaptive in recently injured nurses.

CSF Flow in the Brain in the Context of Normal Pressure Hydrocephalus.

Science.gov (United States)

Bradley, W G

2015-05-01

CSF normally flows back and forth through the aqueduct during the cardiac cycle. During systole, the brain and intracranial vasculature expand and compress the lateral and third ventricles, forcing CSF craniocaudad. During diastole, they contract and flow through the aqueduct reverses. Hyperdynamic CSF flow through the aqueduct is seen when there is ventricular enlargement without cerebral atrophy. Therefore, patients presenting with clinical normal pressure hydrocephalus who have hyperdynamic CSF flow have been found to respond better to ventriculoperitoneal shunting than those with normal or decreased CSF flow. Patients with normal pressure hydrocephalus have also been found to have larger intracranial volumes than sex-matched controls, suggesting that they may have had benign external hydrocephalus as infants. While their arachnoidal granulations clearly have decreased CSF resorptive capacity, it now appears that this is fixed and that the arachnoidal granulations are not merely immature. Such patients appear to develop a parallel pathway for CSF to exit the ventricles through the extracellular space of the brain and the venous side of the glymphatic system. This pathway remains functional until late adulthood when the patient develops deep white matter ischemia, which is characterized histologically by myelin pallor (ie, loss of lipid). The attraction between the bare myelin protein and the CSF increases resistance to the extracellular outflow of CSF, causing it to back up, resulting in hydrocephalus. Thus idiopathic normal pressure hydrocephalus appears to be a "2 hit" disease: benign external hydrocephalus in infancy followed by deep white matter ischemia in late adulthood. © 2015 by American Journal of Neuroradiology.

Back reaction of excitations on a vortex

International Nuclear Information System (INIS)

Arodz, H.; Hadasz, L.

1997-01-01

Excitations of a vortex are usually considered in a linear approximation neglecting their back reaction on the vortex. In the present paper we investigate back reaction of Proca-type excitations on a straight linear vortex in the Abelian Higgs model. We propose an exact ansatz for fields of the excited vortex. From an initial set of six nonlinear field equations we obtain (in a limit of weak excitations) two linear wave equations for the back reaction corrections. Their approximate solutions are found in the cases of plane wave and wave-packet-type excitations. We find that the excited vortex radiates the vector field and that the Higgs field has a very broad oscillating component. copyright 1997 The American Physical Society

Advanced Control Strategy of Back-to-Back PWM Converters in PMSG Wind Power System

Directory of Open Access Journals (Sweden)

Tan Luong Van

2015-01-01

Full Text Available This paper proposes a control scheme of back-to-back PWM converters for the permanent magnet synchronous generator (PMSG wind turbine system. The DC-link voltage can be controlled at the machine-side converter (MSC, while the grid-side converter (GSC controls the grid active power for a maximum power point tracking (MPPT. At the grid fault condition, the DC-link voltage controller is designed using a feedback linearization (FL theory. For the MPPT, a proportional control loop is added to the torque control to reduce the influence of the inertia moment in the wind turbines, which can improve its dynamic performance. The validity of this control algorithm has been verified by the simulation of the 2-MW PMSG wind turbine system.

Assessment of postural load on the back in occupational epidemiology

OpenAIRE

Burdorf, Alex

1992-01-01

textabstractLow-back pain is a common symptom among workers, nearly everyone will be affected by low-back pain at some point in life. This opening line may sound deceptive since low-back pain is usually a self-limiting condition, where recovery without a physician's consultation can be demonstrated in the vast majority of all episodes. Yet, there is ample evidence that the symptom of back pain is recurrent, with one-year recurrence rates reported of more than 60%. In many industrial populatio...

Incorporation of uranium in pyrochlore oxides and pressure-induced phase transitions

Energy Technology Data Exchange (ETDEWEB)

Zhang, F.X., E-mail: zhangfx@umich.edu [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Lang, M.; Tracy, C.; Ewing, R.C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Gregg, D.J.; Lumpkin, G.R. [Institute of Materials Engineering, ANSTO, Locked Bag 2001, Kirrawee DC 2232, NSW (Australia)

2014-11-15

Uranium-doped gadolinium zirconates with pyrochlore structure were studied at ambient and high-pressure conditions up to 40 GPa. The bonding environment of uranium in the structure was determined by x-ray photoelectron and Raman spectroscopies and x-ray diffraction. The uranium valence for samples prepared in air is mainly U{sup 6+}, but U{sup 4+} is present in pyrochlores fabricated in an argon atmosphere. Rietveld refinement of the XRD pattern suggests that uranium ions in pyrochlores are on the 16d site in 6-fold coordination with oxygen. At pressures greater than 22 GPa, the pyrochlore structure transformed to a cotunnite-type phase. The cotunnite high-pressure phase transformed to a defect fluorite structure on the release of pressure. - Graphical abstract: In U-bearing pyrochlore, U ions mainly occupy the 16d site and replace the smaller Zr{sup 4+}, part of the oxygen will occupy the 8b site, which is empty to most pyrochlores. At pressure of 22 GPa, the pyrochlore lattice is not stable and transforms to a cotunnite-type structure. The high-pressure structure is not stable and transform to a fluorite or back to the pyrochlore structure when pressure is released. - Highlights: • We found that U ions mainly occupy the smaller cation site in U-bearing pyrochlore. • Pyrochlore structure is not stable at pressure of more than 20 GPa. • The quenched sample has a pyrochlore or a disordered fluorite structure.

Back Surgery: When Is It a Good Idea?

Science.gov (United States)

... one of the most common ailments seen by family doctors. Back problems typically respond to nonsurgical treatments — such as anti-inflammatory medications, heat and physical therapy. Back surgery might be an option if conservative treatments haven't worked and your pain is ...

Back pain reporting in young girls appears to be puberty-related

Directory of Open Access Journals (Sweden)

Froberg Karsten

2005-11-01

Full Text Available Abstract Background There is a large increase in back pain reporting in the early teens. In no previous study has the prevalence of low back pain been investigated in relation to the onset of puberty. The objective of this study was to establish whether the onset of puberty is associated with back pain reporting in young girls. Methods A subsample of 254 girls aged 8–10 years and 165 girls aged 14–16 years from a cross-sectional survey of 481 children aged 8–10 years and 325 adolescents aged 14–16 years of both sexes. Main outcome measures were back pain defined as low back pain, mid back pain, and/or neck pain in the past month. Other variables of interest were Puberty (five different stages, age, body mass index, and smoking. Independent information on onset of puberty was obtained through a physical examination and on back pain through an individual structured interview. The association was studied between onset of puberty and the outcome variable (the one month period prevalence of back pain, controlling for overweight, and smoking. Odds ratios with 95% confidence intervals were used to describe bivariate associations, logistic regression with robust standard errors was used for multivariate analyses. Results There is a highly significant trend for increased back pain reporting with increasing level of puberty until maturity is reached. The biggest leap appears between the second level (beginning of puberty and the third level (mid puberty and the findings remain after controlling for the covariates. These results emanate from the low back, whereas pain in the mid back and neck do not seem to be linked with pubertal stage. Conclusion In girls, the reporting of low back pain increases in frequency during puberty until maturity, regardless of age. Why some girls are susceptible to back pain in the early stage of puberty is unknown.

The Effect of Fatigue and Instability on Postural Control Parameters in Standing Posture in Healthy Adults and Patients with Chronic Low Back Pain

Directory of Open Access Journals (Sweden)

Amir Hosein Kahlaee

2012-06-01

Full Text Available Background: This study aims at analyzing the effect of fatigue and instability on postural control parameters in both healthy people and patients with the chronic nonspecific low-back pain.Materials and Methods: In this non-experimental case-control study, oscillations of center of pressure were statistically analyzed in 16 healthy people and 15 patients with the chronic nonspecific low back pain. The analysis was conducted through two stages: before and after fatigue and under both stable and unstable surfaces. Results: Under the pre-fatigue, stable condition, there was not any difference between the two groups. Both fatigue and unstable surface changed our variables (sway area, range, velocity, frequency and total power of the signal. All the changes in variables were significant in the low-back pain group; while changes in the healthy group only covered the time-domain variables. The effect of instability was higher than that of fatigue. Conclusion: The postural control system for patients with low-back pain before fatigue and under stable condition, revealed sufficient competence to provide postural stability and its function cannot be differentiated from that in healthy people. Meanwhile, different mechanisms were used by these patients to confront stability challenging factors and further neural activity was required to counteract such factors.

Application of advanced biomechanical methods in studying low back pain – recent development in estimation of lower back loads and large-array surface electromyography and findings

Directory of Open Access Journals (Sweden)

Bazrgari B

2017-07-01

Full Text Available Babak Bazrgari,1 Ting Xia2 1F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, 2Palmer Center for Chiropractic Research, Palmer College of Chiropractic, Davenport, IA, USA Abstract: Low back pain (LBP is a major public health problem and the leading disabling musculoskeletal disorder globally. A number of biomechanical methods using kinematic, kinetic and/or neuromuscular approaches have been used to study LBP. In this narrative review, we report recent developments in two biomechanical methods: estimation of lower back loads and large-array surface electromyography (LA-SEMG and the findings associated with LBP. The ability to estimate lower back loads is very important for the prevention and the management of work-related low back injuries based on the mechanical loading model as one category of LBP classification. The methods used for estimation of lower back loads vary from simple rigid link-segment models to sophisticated, optimization-based finite element models. In general, reviewed reports of differences in mechanical loads experienced in lower back tissues between patients with LBP and asymptomatic individuals are not consistent. Such lack of consistency is primarily due to differences in activities under which lower back mechanical loads were investigated as well as heterogeneity of patient populations. The ability to examine trunk neuromuscular behavior is particularly relevant to the motor control model, another category of LBP classification. LA-SEMG not only is noninvasive but also provides spatial resolution within and across muscle groups. Studies using LA-SEMG showed that healthy individuals exhibit highly organized, symmetric back muscle activity patterns, suggesting an orderly recruitment of muscle fibers. In contrast, back muscle activity patterns in LBP patients are asymmetric or multifocal, suggesting lack of orderly muscle recruitment. LA-SEMG was also shown capable of

Low back pain and lumbar angles in Turkish coal miners

Energy Technology Data Exchange (ETDEWEB)

Sarikaya, S.; Ozdolap, S.; Gumustas, S.; Koc, U. [Zonguldak Karaelmas University, Zonguldak (Turkey). Faculty of Medicine

2007-02-15

This study was designed to assess the incidence of low back pain among Turkish coal miners and to investigate the relationship between angles of the lumbar spine and low back pain in coal miners. Fifty underground workers (Group I) and 38 age-matched surface workers (Group II) were included in the study. All the subjects were asked about low back pain in the past 5 years. The prevalence of low back pain was higher in Group I than in Group II (78.0%, 32.4%, respectively, P {lt} 0.001). The results of the study showed that low back pain occurred in 78.0% of Turkish coal miners. Although the nature of the occupation may have influenced coal miners' lumbar spinal curvature, lumbar angles are not a determinant for low back pain in this population. Further extensive studies involving ergonomic measurements are needed to validate our results for Turkish coal mining industry.

Thermal imaging of high power diode lasers subject to back-irradiance

Science.gov (United States)

Li, C.; Pipe, K. P.; Cao, C.; Thiagarajan, P.; Deri, R. J.; Leisher, P. O.

2018-03-01

CCD-based thermoreflectance imaging and finite element modeling are used to study the two-dimensional (2D) temperature profile of a junction-down broad-area diode laser facet subject to back-irradiance. By determining the temperature rise in the active region (ΔΤAR) at different diode laser optical powers, back-irradiance reflectance levels, and back-irradiance spot locations, we find that ΔΤAR increases by nearly a factor of three when the back-irradiance spot is centered in the absorbing substrate approximately 5 μm away from the active region, a distance roughly equal to half of the back-irradiance spot FWHM (9 μm). This corroborates prior work studying the relationship between the back-irradiance spot location and catastrophic optical damage, suggesting a strong thermal basis for reduced laser lifetime in the presence of back-irradiance for diode lasers fabricated on absorbing substrates.

A comparison between the response of compound semiconductor detectors in single and back-to-back configuration

International Nuclear Information System (INIS)

Auricchio, N.; Donati, A.; Dusi, W.; Perillo, E.; Siffert, P.

2004-01-01

CdTe detectors (3 x 5 mm 2 electrode area and 1 mm thick), mounted in a back-to-back configuration with common anode, have been characterized, aiming at determining the actual regions of these devices giving the best and almost constant spectroscopic performance. This configuration ensures that the maximum paths of the charge carriers correspond to the inter-electrode distances and consequently the spectroscopic performance is essentially the same as for the single coupled detectors, but allows one: - to double the useful absorbing thickness when irradiated in the classical planar parallel field geometry; - to double the pixel area when irradiated in the planar transverse field (PTF) geometry, while the absorbing thickness can be freely adjusted according to the experimental requirements. The tests were performed in PTF geometry by using well collimated photon beams (10-300 keV energy range) obtained by a 20 mm thick tungsten collimator having a 0.1 x 1 or a 0.3 x 1 mm 2 collimating channel. Experimental results concerning the spectroscopic behaviour of the coupled detectors have been compared with those obtained by single devices having the same thickness as the single components or the same total thickness as the coupled device. The results show that the back-to-back configuration does not introduce further significant noise with respect to 1 mm thick single detectors and their spectroscopic performance is similar or better than the one shown by 2 mm thick single devices for fine and wide collimator measurements, and mostly in the uncollimated case

Back extensor muscle endurance test scores in coal miners in Australia

Energy Technology Data Exchange (ETDEWEB)

Stewart, M.; Latimer, J.; Jamieson, M. [University of Sydney, Sydney, NSW (Australia). Faculty of Health and Science, School of Physiotherapy

2003-06-01

Low back pain is a common complaint among those working in the Australian coal mining industry. One test that may be predictive of first-time episodes of low back pain is the Biering-Sorensen test of back extensor endurance strength. While this test has been evaluated in overseas sedentary populations, normative data and the discriminative ability of the test have not been evaluated with coal miners. Eighty-eight coal miners completed a questionnaire for known risk factors for low back pain, performed the Biering-Sorensen test, and undertook a test of aerobic fitness. Data analysis was performed to describe the groups and to determine whether any significant difference existed between those with a past history of low back pain and those without. Significantly lower than expected holding times were found in this group of coal miners (mean 113 s). This result was significantly lower than demonstrated in previous studies. When holding times for those with a past history of low back pain were compared with times for those with no history of low back pain, the difference was not statistically significant, nor was there a significant difference in fitness between those with a past history of low back pain and those without. It is concluded that coal miners in Australia have lower than normal Biering-Sorensen holding times. This lower back holding time does not differ between coal miners with a past history of low back pain and those without.

Backed up and gone...

CERN Multimedia

Computer Security Team

2013-01-01

Remember how easy it is to lose your passwords for web applications (“Don’t let Chrome expose your passwords”)? This time we go bigger and discuss how easy it is to lose the passwords for every wireless access point you’ve visited. You just need to be running Android on your smartphone…   Apparently, Google was already capturing wireless access points during its Streetview campaign but was forced to stop this after complaints from data protection advocates. It was done “mistakenly”. With Google’s Android now dominating the smartphone market, they’re back to their old tricks. As a useful feature, Android (version 2.2 and higher) stores the identifiers (“SSIDs”) of wireless access points and credentials by default, so that you do not have to reissue them on every connection. The interesting part happens when the smartphone is automatically backed up to Google'...

There and Back Again

DEFF Research Database (Denmark)

Danvy, Olivier; Goldberg, Mayer

2002-01-01

We present a programming pattern where a recursive function traverses a data structure---typically a list---at return time. The idea is that the recursive calls get us there (typically to a base case) and the returns get us back again while traversing the data structure. We name this programming...... pattern of traversing a data structure at return time "There And Back Again" (TABA).The TABA pattern directly applies to computing a symbolic convolution. It also synergizes well with other programming patterns, e.g., dynamic programming and traversing a list at double speed. We illustrate TABA...... and dynamic programming with Catalan numbers. We illustrate TABA and traversing a list at double speed with palindromes and we obtain a novel solution to this traditional exercise.A TABA-based function written in direct style makes full use of an Algol-like control stack and needs no heap allocation...

Assessment of postural load on the back in occupational epidemiology

NARCIS (Netherlands)

A. Burdorf (Alex)

1992-01-01

textabstractLow-back pain is a common symptom among workers, nearly everyone will be affected by low-back pain at some point in life. This opening line may sound deceptive since low-back pain is usually a self-limiting condition, where recovery without a physician's consultation can be demonstrated

Back transport: exploration of parents' feelings regarding the transition.

Science.gov (United States)

Kuhnly, J E; Freston, M S

1993-02-01

The purpose of this qualitative study was to explore parents' perceptions and the concepts involved in their preterm infant's back transport from a tertiary neonatal intensive care unit to their home community hospital. A convenience sample of fourteen parents were interviewed five to seven days after the back transport. Following data collection, the analysis of the parents' perceptions regarding the back transport of their premature infant identified a crisis theme that was influenced by several concepts. The subject's positive or negative meaning of the back transport during the pre-crisis phase defined the extent of the crisis during a three day transition period which led to an acceptance of events in the resolution phase. The subjects' perceptions of the previous events of hospitalization and communication of information regarding back transport influenced the meaning of the back transport for them. The extent of crisis during the transition phase was influenced by subjects' perceptions of medical complications, caretaking practice changes, environmental changes, feelings of powerlessness or empowerment, personal coping resources, and support systems available. Resolution in all cases occurred with an acceptance of events. Implications for practice and future research can be identified such as developing and testing education programs to prepare parents for the transition and strengthening the relationship between tertiary and community hospitals.

LOW BACK PAINS –THE ORTHOPAEDIC SURGEON'S ENIGMA

African Journals Online (AJOL)

this century that the low back pain symptom complex has taken on ... of low back pain in 1911 by Goldthwait (1). Major ... no specific diagnosis is made in 80% to 90% of patients ... wound and cures a freeman, he shall receive ten pieces of ...

Characterization and Processing of Non-Uniformities in Back-Illuminated CCDs

Science.gov (United States)

Lemm, Alia D.; Della-Rose, Devin J.; Maddocks, Sally

2018-01-01

In astronomical photometry, Charged Coupled Device (CCD) detectors are used to achieve high precision photometry and must be properly calibrated to correct for noise and pixel non-uniformities. Uncalibrated images may contain bias offset, dark current, bias structure and uneven illumination. In addition, standard data reduction is often not sufficient to “normalize” imagery to single-digit millimagnitude (mmag) precision. We are investigating an apparent non-uniformity, or interference pattern, in a back-illuminated sensor, the Alta U-47, attached to a DFM Engineering 41-cm Ritchey-Chrétien f/8 telescope. Based on the amplitude of this effect, we estimate that instrument magnitude peak-to-valley deviations of 50 mmag or more may result. Our initial testing strongly suggests that reflected skylight from high pressure sodium city lights may be the cause of this interference pattern. Our research goals are twofold: to fully characterize this non-uniformity and to determine the best method to remove this interference pattern from our reduced CCD images.

Feedback control using only quantum back-action

International Nuclear Information System (INIS)

Jacobs, Kurt

2010-01-01

The traditional approach to feedback control is to apply deterministic forces to a system by modifying the Hamiltonian. Here we show that finite-dimensional quantum systems can be controlled purely by exploiting the random quantum back-action of a continuous weak measurement. We demonstrate that, quite remarkably, the quantum back-action of such an adaptive measurement is just as effective at controlling quantum systems as traditional feedback.

A search for back-to-back e+e- pairs in the spontaneous-fission disintegration of 252Cf

International Nuclear Information System (INIS)

Tsunoda, T.; Nakamura, S.; Orito, S.; Minowa, M.

1995-01-01

A back-to-back electron-positron pair is searched for in spontaneous-fission disintegration of 252 Cf. The emission of such a pair, if observed, might be a manifestation of production and prompt decay of a heretofore unknown neutral particle. The emission rate of such a pair is found to be less than (2.5-5.5) . 10 -10 per fission at the 95% confidence level depending on the mass of the hypothetical particle which is between 40 and 200 MeV/c 2 . (orig.)

Acknowledging the back patient

DEFF Research Database (Denmark)

Damsgaard, Janne Brammer; Bastrup, Lene; Norlyk, Annelise

and reluctant to speak out. Therefore, telling about experiences and perceptions is important for back patients in order to feel accepted and acknowledged. The health professionals must incorporate the patients’ narratives as an integral part of the care and treatment. Conclusions: In order to acknowledge...

13 CFR 120.611 - Pools backing Pool Certificates.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Pools backing Pool Certificates. 120.611 Section 120.611 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Secondary Market Certificates § 120.611 Pools backing Pool Certificates. (a) Pool characteristics. As set...

Back Reaction And Local Cosmological Expansion Rate

CERN Document Server

Geshnizjani, G; Geshnizjani, Ghazal; Brandenberger, Robert

2002-01-01

We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single field. We analyze back reaction both in a matter dominated Universe and in a phase of scalar field-driven chaotic inflation. In both cases, we find that the leading infrared terms contributing to the back reaction vanish when the local expansion rate is measured at a fixed value of the matter field which is used as a clock, whereas they do not appear to vanish if the expansion rate is evaluated at a fixed value of the background time. We discuss possible implications for more realistic models with a more complicated matter sector.

Cross friction algometry (CFA): Comparison of pressure pain thresholds between patients with chronic non-specific low back pain and healthy subjects.

Science.gov (United States)

Farasyn, Andre; Lassat, Bert

2016-04-01

Palpation is widely used to assess muscular sensitivity in clinical settings but still remains a subjective evaluation. This cross-sectional study assessed a newly developed cross-friction algometry making palpation measurable. The objective was to investigate the reliability of pressure pain thresholds obtained using Cross-Friction Algometry (CFA-PPTs) measured at the level of Erector spinae and Gluteus maximus central muscle parts, and to compare the CFA-PPTs between patients with chronic nonspecific low back pain (nCLBP) and matching healthy subjects. Patients presenting nCLBP to GP's and send into a Pain Center and healthy subjects recruited via university ad valvas & flyers distribution. 30 patients with nCLBP were measured for cross-friction algometry. Other evaluations consisted of the Visual Analogue Scale (VAS) and the Oswestry Disability Index (ODI). The inter- and intra-reliability were tested and found to be sufficient. The mean CFA-PPT values of the Erector spinae at levels T8, T10, L1 & L3 and the Gluteus maximus of the nCLBP group were significantly lower (p ≤ 0.001) when compared to the CFA-PPT values of the healthy group. The greatest difference (-58%) was found at L1 Erector spinae level and at the superior part of the Gluteus maximus measuring point (-59%). Within the group of patients with nCLBP it was surprising to notice that there was no significant correlation between all the reference points measured using CFA-PPTs and the outcomes of the VAS and ODI scores. With the aid of CFA, the importance of local muscular disorder in the lumbar part of the Erector spinae and Gluteus maximus in patients with nCLBP is obviously demonstrated, but also reveals the very large inter-individual differences in muscular fibrosis sensitivity and/or pain behavior in daily life. This possibly re-opens the debate on which influences can be put forward as the most important: the central or the peripheral sensitization system. Copyright © 2015 Elsevier Ltd. All

Back to School

Directory of Open Access Journals (Sweden)

Pamela Osmond

2014-10-01

Full Text Available The Back to School of the title refers to post- school or second chance education in America. Mike Rose’s focus is on adult remedial (sic and occupational education.  However, although he writes about America, it is hard not to read this little book without a constant alternative reading of second chance learning or Technical and Further Education in the Australian context.

Formation Mechanism of Surface Crack in Low Pressure Casting of A360 Alloy

Science.gov (United States)

Liu, Shan-Guang; Cao, Fu-Yang; Ying, Tao; Zhao, Xin-Yi; Liu, Jing-Shun; Shen, Hong-Xian; Guo, Shu; Sun, Jian-Fei

2017-12-01

A surface crack defect is normally found in low pressure castings of Al alloy with a sudden contraction structure. To further understand the formation mechanism of the defect, the mold filling process is simulated by a two-phase flow model. The experimental results indicate that the main reason for the defect deformation is the mismatching between the height of liquid surface in the mold and pressure in the crucible. In the case of filling, a sudden contraction structure with an area ratio smaller than 0.5 is obtained, and the velocity of the liquid front increases dramatically with the influence of inertia. Meanwhile, the pressurizing speed in the crucible remains unchanged, resulting in the pressure not being able to support the height of the liquid level. Then the liquid metal flows back to the crucible and forms a relatively thin layer solidification shell on the mold wall. With the increasing pressure in the crucible, the liquid level rises again, engulfing the shell and leading to a surface crack. As the filling velocity is characterized by the damping oscillations, surface cracks will form at different heights. The results shed light on designing a suitable pressurizing speed for the low pressure casting process.

Experiences of Rehabilitation Professionals with the Implementation of a Back School for Patients with Chronic Low Back Pain: A Qualitative Study

Directory of Open Access Journals (Sweden)

Stefan Peters

2016-01-01

Full Text Available A standardized curriculum back school (CBS has been recommended for further dissemination in medical rehabilitation in Germany. However, implementation of self-management education programs into practice is challenging. In low back pain care, individual factors of professionals could be decisive regarding implementation fidelity. The study aim was to explore attitudes and experiences of professionals who conducted the back school. Qualitative interviews were led with 45 rehabilitation professionals. The data were examined using thematic analysis. Three central themes were identified: (a “back school as a common thread,” (b “theory versus practice,” and (c “participation and patient-centeredness.” The CBS and its manual were frequently described positively because they provide structure. However, specified time was mentioned critically and there were heterogeneous perceptions regarding flexibility in conducting the CBS. Theory and practice in the CBS were discussed concerning amount, distribution, and conjunction. Participation and patient-centeredness were mainly mentioned in terms of amount and heterogeneity of participation as well as the demand for competences of professionals. Factors were detected that may either positively or negatively influence the implementation fidelity of self-management education programs. The results are explorative and provide potential explanatory mechanisms for behavior and acceptance of rehabilitation professionals regarding the implementation of biopsychosocial back schools.

Flight Bags as a Cause of Back Injuries Among Commercial Pilots.

Science.gov (United States)

Kanumuri, Vamsi S R; Zautke, John L; Dorevitch, Samuel

2015-06-01

Pilots of fixed wing commercial aircraft face numerous occupational hazards. Low back pain is among the most common and costly workplace injury, though relatively little is known about causes of back injuries among pilots. The awkward lifting and twisting maneuvers in the flight deck to position flight bags has not been described as a cause of occupational back injury among pilots. A case series of low back injuries among pilots was identified and described by a retrospective review of charts at an airport-based clinic. Circumstances of occupational back injury, initial direct medical costs, treatment, and work status following evaluation were described. Over a 6-yr period, 37 occupational low back injuries among 35 pilots were evaluated and treated. Of these, 24 (65%) involved flight bags. Only 27% of pilots with flight bag-associated injuries were returned to work after initial evaluation; medications with sedating properties were frequently required for treatment. Injuries due to slips, trips, and falls, typically in jet bridges or associated with hotel shuttles, were common among pilots with back injuries not related to flight bags. The majority of occupational low back injuries seen among pilots in an airport based clinic were attributable to use of flight bags. Substituting electronic flight bags for traditional flight bags could contribute to back injury prevention among pilots.

Disability in older adults with acute low back pain: the study Back Complaints in the Elderly - (Brazil).

Science.gov (United States)

Aguiar, Alessandra Regina Silva Araujo; Ribeiro-Samora, Giane Amorim; Pereira, Leani Souza Maximo; Godinho, Larissa Birro; Assis, Marcella Guimarães

The increase in the older adult and oldest old population in Brazil is growing. This phenomenon may be accompanied by an increase in musculoskeletal symptoms such as low back pain. This condition is usually associated with disability. To verify the association between pain intensity and disability in older adults with acute low back pain and assess whether these variables differ depending on the age group and marital status. This is a cross-sectional study conducted with 532 older adults with acute low back pain episodes. Pain intensity was assessed through the Numeric Pain Scale and disability through the Late Life Function and Disability Instrument, which shows two dimensions: "frequency" and "limitation" in performing activities. The association between pain and disability was analyzed. For the interaction effect between age groups and marital status, we found that the oldest old living with a partner performed activities of the personal domain less often compared to the oldest old living alone. The oldest old group living with a partner had a lower frequency of performing activities, but did not report feeling limited. The association of pain with disability was minimal (rholow back pain was influenced by the interaction between age groups and marital status and is not associated with pain intensity. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Predictive risk factors for chronic low back pain in Parkinson's disease.

Science.gov (United States)

Ozturk, Erhan Arif; Kocer, Bilge Gonenli

2018-01-01

Although previous studies have reported that the prevalence of low back pain in Parkinson's disease was over 50% and low back pain was often classified as chronic, risk factors of chronic low back pain have not been previously investigated. The aim of this study was to determine the predictive risk factors of chronic low back pain in Parkinson's disease. One hundred and sixty-eight patients with Parkinson's disease and 179 controls were consecutively included in the study. Demographic data of the two groups and disease characteristics of Parkinson's disease patient group were recorded. Low back pain lasting for ≥3 months was evaluated as chronic. Firstly, the bivariate correlations were calculated between chronic low back pain and all possible risk factors. Then, a multivariate regression was used to evaluate the impact of the predictors of chronic low back pain. The frequency of chronic low back pain in Parkinson's disease patients and controls were 48.2% and 26.7%, respectively (p chronic low back pain in Parkinson's disease were general factors including age (odds ratio = 1.053, p = 0.032) and Hospital Anxiety and Depression Scale - Depression subscore (odds ratio = 1.218, p = 0.001), and Parkinson's disease-related factors including rigidity (odds ratio = 5.109, p = 0.002) and posture item scores (odds ratio = 5.019, p = 0.0001). The chronic low back pain affects approximately half of the patients with Parkinson's disease. Prevention of depression or treatment recommendations for managing depression, close monitoring of anti- parkinsonian medication to keep motor symptoms under control, and attempts to prevent, correct or reduce abnormal posture may help reduce the frequency of chronic low back pain in Parkinson's disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Feedback Regulation of Intracellular Hydrostatic Pressure in Surface Cells of the Lens

Science.gov (United States)

Gao, Junyuan; Sun, Xiurong; White, Thomas W.; Delamere, Nicholas A.; Mathias, Richard T.

2015-01-01

In wild-type lenses from various species, an intracellular hydrostatic pressure gradient goes from ∼340 mmHg in central fiber cells to 0 mmHg in surface cells. This gradient drives a center-to-surface flow of intracellular fluid. In lenses in which gap-junction coupling is increased, the central pressure is lower, whereas if gap-junction coupling is reduced, the central pressure is higher but surface pressure is always zero. Recently, we found that surface cell pressure was elevated in PTEN null lenses. This suggested disruption of a feedback control system that normally maintained zero surface cell pressure. Our purpose in this study was to investigate and characterize this feedback control system. We measured intracellular hydrostatic pressures in mouse lenses using a microelectrode/manometer-based system. We found that all feedback went through transport by the Na/K ATPase, which adjusted surface cell osmolarity such that pressure was maintained at zero. We traced the regulation of Na/K ATPase activity back to either TRPV4, which sensed positive pressure and stimulated activity, or TRPV1, which sensed negative pressure and inhibited activity. The inhibitory effect of TRPV1 on Na/K pumps was shown to signal through activation of the PI3K/AKT axis. The stimulatory effect of TRPV4 was shown in previous studies to go through a different signal transduction path. Thus, there is a local two-legged feedback control system for pressure in lens surface cells. The surface pressure provides a pedestal on which the pressure gradient sits, so surface pressure determines the absolute value of pressure at each radial location. We speculate that the absolute value of intracellular pressure may set the radial gradient in the refractive index, which is essential for visual acuity. PMID:26536260

Lower back pain and absenteeism among professional public transport drivers.

Science.gov (United States)

Kresal, Friderika; Roblek, Vasja; Jerman, Andrej; Meško, Maja

2015-01-01

Drivers in public transport are subjected to lower back pain. The reason for the pain is associated with the characteristics of the physical position imposed on the worker while performing the job. Lower back pain is the main cause of absenteeism among drivers. The present study includes 145 public transport drivers employed as professional drivers for an average of 14.14 years. Analysis of the data obtained in the study includes the basic descriptive statistics, χ(2) test and multiple regression analysis. Analysis of the incidence of lower back pain showed that the majority of our sample population suffered from pain in the lower back. We found that there are no statistically significant differences between the groups formed by the length of service as a professional driver and incidence of lower back pain; we were also interested in whether or not the risk factors of lower back pain affects the absenteeism of city bus drivers. Analysis of the data has shown that the risk factors of pain in the lower part of the spine do affect the absenteeism of city bus drivers.

The safety of pressurized water reactors

International Nuclear Information System (INIS)

Panossian, J.; Tanguy, P.

1991-01-01

In this paper we present a review of the status of the safety level of modern pressurized water reactors, that is to say those that meet the safety criteria accepted today by the international nuclear community. We will mainly rely on the operating experience and the Probabilistic Safety Assessments concerning French reactors. We will not back over the basic safety concepts of these reactors, which are well known. We begin with a brief review of some of the lessons learned from the two main accidents discussed in the present meeting. Three Mile Island and Chernobyl, without entering into details presented in previous papers. The presentation ends with a rather lengthy conclusion, aimed more at those not directly involved in the technical details of nuclear safety matters

Back to work for the PS

CERN Multimedia

2006-01-01

On 22 June, the PS's rotating machine started turning again for the first time since its enforced shutdown one month ago (see Bulletin No. 23-24/2006) - and the PS was back in operation the very next day! A team from Siemens worked their socks off, 6 days a week for one month (including public holidays), to repair the electrical power supply in collaboration with the AB/PO Group's Main Power Converters (MPC) Section. The generator's faulty rotor was dismantled and replaced by the renovated spare rotor. The multitude of electrical and mechanical connections together with the sheer weight of the rotor (80 tonnes) made this an extremely complex job. The AB/PO Group used the shutdown to test a back-up solution for the PS power supply. The accelerator was directly wired up to the 18 kV electrical network via a 13 MVA transformer, installed at the end of the 1970s but never used. This solution succeeded in bringing the PS back into operation but at limited energy and frequency. Just 14 GeV could be achieved, whic...

Cross-sectional survey of attitudes and beliefs about back pain in New Zealand

Science.gov (United States)

Darlow, Ben; Perry, Meredith; Stanley, James; Mathieson, Fiona; Melloh, Markus; Baxter, G David; Dowell, Anthony

2014-01-01

Objectives To explore the prevalence of attitudes and beliefs about back pain in New Zealand and compare certain beliefs based on back pain history or health professional exposure. Design Population-based cross-sectional survey. Setting Postal survey. Participants New Zealand residents and citizens aged 18 years and above. 1000 participants were randomly selected from the New Zealand Electoral Roll. Participants listed on the Electoral Roll with an overseas postal address were excluded. 602 valid responses were received. Measures Attitudes and beliefs about back pain were measured with the Back Pain Attitudes Questionnaire (Back-PAQ). The interaction between attitudes and beliefs and (1) back pain experience and (2) health professional exposure was investigated. Results The lifetime prevalence of back pain was reported as 87% (95% CI 84% to 90%), and the point prevalence as 27% (95% CI 24% to 31%). Negative views about the back and back pain were prevalent, in particular the need to protect the back to prevent injury. People with current back pain had more negative overall scores, particularly related to back pain prognosis. There was uncertainty about links between pain and injury and appropriate physical activity levels during an episode of back pain. Respondents had more positive views about activity if they had consulted a health professional about back pain. The beliefs of New Zealanders appeared to be broadly similar to those of other Western populations. Conclusions A large proportion of respondents believed that they needed to protect their back to prevent injury; we theorise that this belief may result in reduced confidence to use the back and contribute to fear avoidance. Uncertainty regarding what is a safe level of activity during an episode of back pain may limit participation. People experiencing back pain may benefit from more targeted information about the positive prognosis. The provision of clear guidance about levels of activity may enable

Psychogenic Low-Back Pain and Hysterical Paralysis in Adolescence.

Science.gov (United States)

Kanchiku, Tsukasa; Suzuki, Hidenori; Imajo, Yasuaki; Yoshida, Yuichiro; Nishida, Norihiro; Taguchi, Toshihiko

2017-10-01

A retrospective review. The purpose of this study was to investigate the clinical outcomes in adolescents diagnosed with psychogenic low-back pain and hysterical paralysis and to evaluate the efficacy of differential diagnosis methods. The incidence of low-back pain in adolescence is similar to that in adults, but the causes of low-back pain are difficult to determine in most cases. For these patients, a definitive diagnosis of psychogenic low-back pain and hysterical paralysis as well as adequate treatment are clinically important to avoid unnecessary surgical treatment. Eleven patients (3 males and 8 females; mean age, 16.5 years; range, 13-19 y) diagnosed with psychogenic low-back pain and hysterical paralysis were followed up for 2-10.25 years (mean, 4.67 y). Nonorganic signs were observed in almost all patients. For the purpose of excluding organic disorders, the thiopentone pain study was used in patients who complained mainly of pain, and motor evoked potentials using transcranial magnetic stimulation were measured in patients experiencing primarily muscle weakness. The psychiatric diagnosis was neurosis in 9 patients, whereas it was psychosomatic disorder in 2 patients. Conservative treatment, such as physiotherapy, was performed, and at the final follow-up evaluation, outcomes were regarded as excellent in 7 patients and good in 4 patients. The prognosis of psychogenic low-back pain and hysterical paralysis in adolescence is relatively good. However, it is important to understand the characteristics of psychogenic low-back pain and hysterical paralysis in childhood and young adulthood and to perform accurate diagnosis by screening for nonorganic signs and excluding organic disorders by using the thiopentone pain study and motor evoked potentials obtained using transcranial magnetic stimulation.

Feasibility of the STarT back screening tool in chiropractic clinics: a cross-sectional study of patients with low back pain

DEFF Research Database (Denmark)

Kongsted, Alice; Johannesen, Else; Leboeuf-Yde, Charlotte

2011-01-01

The STarT back screening tool (SBT) allocates low back pain (LBP) patients into three risk groups and is intended to assist clinicians in their decisions about choice of treatment. The tool consists of domains from larger questionnaires that previously have been shown to be predictive of non-reco...

Low back pain tied to spinal endometriosis.

Science.gov (United States)

Dongxu, Zhao; Fei, Yin; Xing, Xiao; Bo-Yin, Zhang; Qingsan, Zhu

2014-05-01

Case report. We present a case of endometriosis of lumbar vertebrae. The literatures are reviewed with endometriosis of spine. Endometriosis is a common condition, which is defined as endometrial tissue lying outside the endometrial cavity. It is usually found within the peritoneal cavity, predominantly within the pelvis, commonly on the uterosacral ligaments. It can also be found in other sites such as umbilicus, abdominal scars, nasal passages and pleural cavity. But it is very rarely seen in the spine, with no report of endometriosis found in the lumbar vertebrae. A 33-year-old woman presented with severe low back pain. She had the low back pain periodically for 3 years, and the pain was associated with menstruation. Radiographs showed a lesion in the posterior L3 body. After surgery, tissue biopsy indicated the presence of endometrial tissue in the lesion and thus confirmed endometriosis. Most cases of spine endometriosis that have been reported are usually found inside spinal canal, endorachis or spinal cord. But spinal vertebrae can also be involved in endometriosis. Although endometriosis is a rare possible cause of periodical low back pain in women of childbearing age, we suggest that if a woman suffering from periodical low back pain is encountered, do not ignore the possibility of endometriosis in the spine.

Normative data on the n-back task for children and young adolescents.

Science.gov (United States)

Pelegrina, Santiago; Lechuga, M Teresa; García-Madruga, Juan A; Elosúa, M Rosa; Macizo, Pedro; Carreiras, Manuel; Fuentes, Luis J; Bajo, M Teresa

2015-01-01

The n-back task is a frequently used measure of working memory (WM) in cognitive neuroscience research contexts, and it has become widely adopted in other areas over the last decade. This study aimed to obtain normative data for the n-back task from a large sample of children and adolescents. To this end, a computerized verbal n-back task with three levels of WM load (1-back, 2-back, and 3-back) was administered to 3722 Spanish school children aged 7-13 years. Results showed an overall age-related increase in performance for the different levels of difficulty. This trend was less pronounced at 1-back than at 2-back when hits were considered. Gender differences were also observed, with girls outperforming boys although taking more time to respond. The theoretical implications of these results are discussed. Normative data stratified by age and gender for the three WM load levels are provided.

Normative data on the n-back task for children and young adolescents

Directory of Open Access Journals (Sweden)

Santiago ePelegrina

2015-10-01

Full Text Available The n-back task is a frequently used measure of working memory (WM in cognitive neuroscience research contexts, and it has become widely adopted in other areas over the last decade. This study aimed to obtain normative data for the n-back task from a large sample of children and adolescents. To this end, a computerized verbal n-back task with three levels of WM load (1-back, 2-back and 3-back was administered to 3722 Spanish school children aged 7–13 years. Results showed an overall age-related increase in performance for the different levels of difficulty. This trend was less pronounced at 1-back than at 2-back when hits were considered. Gender differences were also observed, with girls outperforming boys although taking more time to respond. The theoretical implications of these results are discussed. Normative data stratified by age and gender for the three WM load levels are provided.

Diverse alternative back-splicing and alternative splicing landscape of circular RNAs

Science.gov (United States)

Zhang, Xiao-Ou; Dong, Rui; Zhang, Yang; Zhang, Jia-Lin; Luo, Zheng; Zhang, Jun; Chen, Ling-Ling; Yang, Li

2016-01-01

Circular RNAs (circRNAs) derived from back-spliced exons have been widely identified as being co-expressed with their linear counterparts. A single gene locus can produce multiple circRNAs through alternative back-splice site selection and/or alternative splice site selection; however, a detailed map of alternative back-splicing/splicing in circRNAs is lacking. Here, with the upgraded CIRCexplorer2 pipeline, we systematically annotated different types of alternative back-splicing and alternative splicing events in circRNAs from various cell lines. Compared with their linear cognate RNAs, circRNAs exhibited distinct patterns of alternative back-splicing and alternative splicing. Alternative back-splice site selection was correlated with the competition of putative RNA pairs across introns that bracket alternative back-splice sites. In addition, all four basic types of alternative splicing that have been identified in the (linear) mRNA process were found within circRNAs, and many exons were predominantly spliced in circRNAs. Unexpectedly, thousands of previously unannotated exons were detected in circRNAs from the examined cell lines. Although these novel exons had similar splice site strength, they were much less conserved than known exons in sequences. Finally, both alternative back-splicing and circRNA-predominant alternative splicing were highly diverse among the examined cell lines. All of the identified alternative back-splicing and alternative splicing in circRNAs are available in the CIRCpedia database (http://www.picb.ac.cn/rnomics/circpedia). Collectively, the annotation of alternative back-splicing and alternative splicing in circRNAs provides a valuable resource for depicting the complexity of circRNA biogenesis and for studying the potential functions of circRNAs in different cells. PMID:27365365

Application of neural networks to prediction of phase transport characteristics in high-pressure two-phase turbulent bubbly flows

International Nuclear Information System (INIS)

Yang, A.-S.; Kuo, T.-C.; Ling, P.-H.

2003-01-01

The phase transport phenomenon of the high-pressure two-phase turbulent bubbly flow involves complicated interfacial interactions of the mass, momentum, and energy transfer processes between phases, revealing that an enormous effort is required in characterizing the liquid-gas flow behavior. Nonetheless, the instantaneous information of bubbly flow properties is often desired for many industrial applications. This investigation aims to demonstrate the successful use of neural networks in the real-time determination of two-phase flow properties at elevated pressures. Three back-propagation neural networks, trained with the simulation results of a comprehensive theoretical model, are established to predict the transport characteristics (specifically the distributions of void-fraction and axial liquid-gas velocities) of upward turbulent bubbly pipe flows at pressures covering 3.5-7.0 MPa. Comparisons of the predictions with the test target vectors indicate that the averaged root-mean-squared (RMS) error for each one of three back-propagation neural networks is within 4.59%. In addition, this study appraises the effects of different network parameters, including the number of hidden nodes, the type of transfer function, the number of training pairs, the learning rate-increasing ratio, the learning rate-decreasing ratio, and the momentum value, on the training quality of neural networks.

Nonlinear Control of Back-to-Back VSC-HVDC System via Command-Filter Backstepping

Directory of Open Access Journals (Sweden)

Jie Huang

2017-01-01

Full Text Available This paper proposed a command-filtered backstepping controller to improve the dynamic performance of back-to-back voltage-source-converter high voltage direct current (BTB VSC-HVDC. First, the principle and model of BTB VSC-HVDC in abc and d-q frame are described. Then, backstepping method is applied to design a controller to maintain the voltage balance and realize coordinated control of active and reactive power. Meanwhile, command filter is introduced to deal with the problem of input saturation and explosion of complexity in conventional backstepping, and a filter compensation signal is designed to diminish the adverse effects caused by the command filter. Next, the stability and convergence of the whole system are proved via the Lyapunov theorem of asymptotic stability. Finally, simulation results are given to demonstrate that proposed controller has a better dynamic performance and stronger robustness compared to the traditional PID algorithm, which also proves the effectiveness and possibility of the designed controller.

Effects of McGill stabilization exercises and conventional physiotherapy on pain, functional disability and active back range of motion in patients with chronic non-specific low back pain.

Science.gov (United States)

Ghorbanpour, Arsalan; Azghani, Mahmoud Reza; Taghipour, Mohammad; Salahzadeh, Zahra; Ghaderi, Fariba; Oskouei, Ali E

2018-04-01

[Purpose] The aim of this study was to compare the effects of "McGill stabilization exercises" and "conventional physiotherapy" on pain, functional disability and active back flexion and extension range of motion in patients with chronic non-specific low back pain. [Subjects and Methods] Thirty four patients with chronic non-specific low back pain were randomly assigned to McGill stabilization exercises group (n=17) and conventional physiotherapy group (n=17). In both groups, patients performed the corresponding exercises for six weeks. The visual analog scale (VAS), Quebec Low Back Pain Disability Scale Questionnaire and inclinometer were used to measure pain, functional disability, and active back flexion and extension range of motion, respectively. [Results] Statistically significant improvements were observed in pain, functional disability, and active back extension range of motion in McGill stabilization exercises group. However, active back flexion range of motion was the only clinical symptom that statistically increased in patients who performed conventional physiotherapy. There was no significant difference between the clinical characteristics while compared these two groups of patients. [Conclusion] The results of this study indicated that McGill stabilization exercises and conventional physiotherapy provided approximately similar improvement in pain, functional disability, and active back range of motion in patients with chronic non-specific low back pain. However, it appears that McGill stabilization exercises provide an additional benefit to patients with chronic non-specific low back, especially in pain and functional disability improvement.

Provocative diskography: safety and predictive value in the outcome of spinal fusion or pain intervention for chronic low-back pain

Directory of Open Access Journals (Sweden)

Willems PC

2014-12-01

Full Text Available Paul C Willems Department of Orthopedic Surgery, CAPHRI Research School, Maastricht University Medical Center, Maastricht, the Netherlands Abstract: There is still no clear definition of diskogenic low-back pain and no consensus on a generally agreed test, such as provocative diskography (PD, to diagnose painful disk degeneration, and probably more importantly, to predict the outcome of therapy intended to reduce pain that is presumed to be diskogenic in nature. Nevertheless, PD is the most specific procedure to diagnose diskogenic low-back pain. Its accuracy, however, is rather low or at best unknown. Although rare, the most prevalent complication, postdiskography diskitis, can be devastating for the individual patient, so all measures, like strict sterile conditions and antibiotic prophylaxis, should be taken to avoid this complication. It is advised to perform the procedure in a pressure-controlled way with a constant low flow, and optionally computed tomography imaging. PD should not be performed in morphologically normal disks. A standardized execution of the test should be established in order to perform high-quality studies to determine its accuracy to lead to meaningful interventions, and find best practices for diagnosis and treatment of diskogenic back pain. Possibly, PD may have detrimental effects on the disk, causing early degeneration, although it is unknown whether this will be related to clinical symptoms. Especially with these possible adverse side effects in mind, the risk–benefit ratio with the lack of clear benefits from treatments provided, and possible complications of disk puncture, the rationale for PD is questionable, which should be stressed to patients in the process of shared decision making. Diskography as a stand-alone test is not recommended in clinical decision making for patients with chronic low-back pain. Keywords: provocative diskography, chronic low-back pain, prognostic accuracy, spinal fusion, pain

Quebec Back Pain Disability Scale, Low Back Outcome Score and revised Oswestry low back pain disability scale for patients with low back pain due to degenerative disc disease: evaluation of Polish versions.

Science.gov (United States)

Misterska, Ewa; Jankowski, Roman; Glowacki, Maciej

2011-12-15

Evaluation and comparison of translated and culturally adapted self-reported measurements. The aim of this prospective study was to cross-culturally adapt the Polish versions of Revised Oswestry Disability Index (RODI-PL), Quebec Back Pain Disability Scale (QDS-PL), and the Low Back Outcome Score (LBOS-PL). The application of instruments in English, which have undergone translation must be subjected to validation studies. Such studies are necessary above all for instruments that have been adapted to establish their value and usefulness in studies of patient populations where English is not the native language. The translation was carried out according to International Quality of Life Association (IQOLA) Project and consisted of the following stages: translation, synthesis of the translations, back translation, expert committee, and testing of the prefinal versions of questionnaires. Eighty-five consecutive patients with low back pain due to spinal disc herniation and degenerative changes completed the QDS-PL, RODI-PL, LBOS-PL, and a Visual Analogue Scale twice within 2-day intervals. Mean duration of LBP was 45.9 months SD 55.5. The evaluation of degenerative changes in the lumbar region was carried out according to the Modic scale. Twenty-nine patients were categorized at type I, 4 patients were registered as type II, and 52 patients were type III. Cronbach α values for the LBOS-PL equaled 0.77, for the RODI-PL 0.85, and 0.95 for the QDS-PL. Item-total correlation confirmed that all scales are internally consistent. Test-retest reliability was excellent for RODI-PL and QDS-PL, but poor for LBOS-PL (0.88, 0.93, and 0.34, respectively). All questionnaires were significantly intercorrelated. We identified the strongest correlation between QDS-PL and RODI-PL (0.823, P < 0.001). The statistically significant correlation was identified between the QDS-PL and Modic Classification (rS = 0.226 P = 0.038). QBPDS-PL and RODI-PL are reliable and valid. Furthermore

Static pressure and temperature coefficients of laboratory standard microphones

DEFF Research Database (Denmark)

Rasmussen, Knud

1996-01-01

of the microphone. The static pressure and temperature coefficients were determined experimentally for about twenty samples of type BK 4160 and BK 4180 microphones. The results agree almost perfectly with the predictions for BK 4160, while some modifications of the lumped parameter values are called for to make......-order approximation of resonances in the back cavity. It was found that each of the coefficients, for a given type of microphone, can be expressed by a single function when the coefficients are normalized by their low-frequency value and the frequency axis normalized by the individual resonance frequency...

Back Pain - Multiple Languages

Science.gov (United States)

... List of All Topics All Back Pain - Multiple Languages To use the sharing features on this page, please enable JavaScript. Arabic (العربية) ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated on 31 May 2018

specific low back pain

African Journals Online (AJOL)

2015-09-01

Sep 1, 2015 ... 2Department of Medicine, School of Medicine and Dentistry, University of Ghana. ... ly, 10% to 20% of patients with low back pain develop ... directly because of illness which are not health care ... activity as regards the treatment outcomes of chronic .... maximal training at 70-80% maximum heart rate).

Back-contacted BaSi

NARCIS (Netherlands)

Vismara, R.; Isabella, O.; Zeman, M.

2017-01-01

We present the optical investigation of a novel back-contacted architecture for solar cells based on a thin barium (di)silicide (BaSi₂) absorber. First, through the analysis of absorption limits of different semiconducting materials, we show the potential of BaSi₂ for

Back muscle fatigue of younger and older adults with and without chronic low back pain using two protocols: A case-control study.

Science.gov (United States)

da Silva, Rubens A; Vieira, Edgar R; Cabrera, Marcos; Altimari, Leandro R; Aguiar, Andreo F; Nowotny, Alexandre H; Carvalho, Adriana F; Oliveira, Marcio R

2015-12-01

The purpose of this study was to compare back muscle fatigue of younger and older participants with and without chronic low back pain (CLBP). Twenty participants without and 20 with nonspecific CLBP participated in this study. Each group contained 10 younger (50% males; mean age: 31 ± 6 yrs) and 10 older adults (50% males; age mean: 71 ± 7 yrs). Two isometric fatigue protocols were presented randomly: (1) to maintain the unsupported trunk at the horizontal position while on a 45° Roman chair for a minute, and (2) to maintain a 10% of body weight box close to the trunk in the upright position for a minute. Surface electromyography (EMG) signals from the back (multifidus and iliocostalis) and one hip (biceps femoris) muscles were recorded bilaterally, and the median frequency fatigue estimate from linear regression slopes of the EMG time-series was computed. There were no significant (P > 0.05) age effects, and group-by-age interaction in both isometric and functional fatigue tasks. However, the CLBP groups (both younger and old) displayed more back fatigue than people without CLBP in both fatigue protocols (P size varying of d = 0.17-0.32). This study was sensitive to discriminate that individuals with CLBP did present significantly more pronounced EMG back fatigue than people without CLBP, in both younger and older adults. These results have significant clinical implications for low back pain rehabilitation programs with regard to endurance assessment in both younger and older. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cavitation inception in nozzle-plate and wire mesh pressure droppers in water and sodium

International Nuclear Information System (INIS)

Collinson, A.E.

1976-01-01

Cavitation tests on multi-hole nozzle plates and wire meshes approximately 100mm diameter in water at 20 deg C and sodium at 300 deg C are described. These pressure dropping elements were mounted in recirculating loops where cavitation was induced by gradually lowering the back-ground pressure at constant flow. Cavitation was detected acoustically using wall mounted piezoelectric microphones, the signal being displayed on a ratemeter recording individual cavitation events. For nozzle plates, cavitation started intermittently as the pressure was lowered, the noise level suddenly increasing at a critical cavitation number sigma. For meshes the intermittent region was absent. Values of sigma for nozzles and meshes were similar in water and sodium for the conditions prevailing during the tests. It was apparent that cavitation took place on the axes of vortices both in the free stream and close to nozzle curved surfaces

Analysis of Accuracy and Epoch on Back-propagation BFGS Quasi-Newton

Science.gov (United States)

Silaban, Herlan; Zarlis, Muhammad; Sawaluddin

2017-12-01

Back-propagation is one of the learning algorithms on artificial neural networks that have been widely used to solve various problems, such as pattern recognition, prediction and classification. The Back-propagation architecture will affect the outcome of learning processed. BFGS Quasi-Newton is one of the functions that can be used to change the weight of back-propagation. This research tested some back-propagation architectures using classical back-propagation and back-propagation with BFGS. There are 7 architectures that have been tested on glass dataset with various numbers of neurons, 6 architectures with 1 hidden layer and 1 architecture with 2 hidden layers. BP with BFGS improves the convergence of the learning process. The average improvement convergence is 98.34%. BP with BFGS is more optimal on architectures with smaller number of neurons with decreased epoch number is 94.37% with the increase of accuracy about 0.5%.

Is active participation in specific sport activities linked with back pain?

DEFF Research Database (Denmark)

Mogensen, A.M.; Gausel, AM; Wedderkopp, Niels

2007-01-01

A cross-sectional survey of 439 children/adolescents aged 12-13, living in Odense, Denmark, in the year 2001. To investigate (1) if there is any difference in back pain reporting among those practising specific sports as compared with non-performers and (2) if there is an association between...... specific kinds of sports and self-reported back problems. Back pain is a common complaint in young people and physical inactivity is generally thought to contribute to this. However, some specific sport activities may be detrimental or beneficial to the spine. Information was collected through a semi......-structured interview, a physical examination, and a questionnaire. Associations for back pain, low back pain, mid back pain and neck pain in the preceding month were investigated in relation to specific sports. Associations were controlled for body mass index, puberty stage and sex. There was no association between...

Mechanical and transport properties of rocks at high temperatures and pressures. Task II. Fracture permeability of crystalline rocks as a function of temperature, pressure, and hydrothermal alteration. Final report

Energy Technology Data Exchange (ETDEWEB)

Johnson, B.

1985-11-01

Pore-fluid chemical interactions on both short and long time scales can significantly change the permeability of a rock. Measurement of the permeability variations requires adaption and modification on standard measurement systems, with special attention given to pore-fluid flow rates and metal corrosion of system components. In this report, system requirements and capabilities are reviewed, analyzed, and recommendations made. Special attention is given to the choice of corrosion resistant metals, fluid-flow systems, back-pressure systems, jacketing materials, and flow-rate measurement. On the basis of this study, an economical, highly flexible, permeability system was designed and built. The system allows measurement of permeability over the darcy to nanodarcy range, using geologically meaningful, chemically reactive, pore fluids under constant volume flow rates as small as 0.2 ml/day at temperatures in excess of 300C, fluid pressures to 20 MPa, and confining pressures to 100 MPa. 7 refs., 3 figs., 1 tab.

Developmental trajectories in primary schoolchildren using n-back task

Directory of Open Access Journals (Sweden)

Mónica eLópez-Vicente

2016-05-01

Full Text Available Background: Neuropsychological instruments to assess cognitive trajectories during childhood in epidemiological studies are needed. This would improve neurodevelopment characterization in order to identify its potential determinants. We aimed to study whether repeated measures of n-back, a working memory task, detect developmental trajectories in schoolchildren during a one-year follow-up.Methods: We administered the n-back task to 2,897 healthy children aged 7-11 years old from 39 schools in Barcelona (Spain. The task consisted of 2 levels of complexity or loads (2- and 3-back and 2 different stimuli (numbers and words. Participants performed the task four times from January 2012 to March 2013. To study the trajectories during the follow-up, we performed linear mixed-effects models including school, individual and age as random effects.Results: We observed improvements related to age in n-back outcomes d’, HRT and accuracy, as well as reduced cognitive growth at older ages in d’ and HRT. Greater improvements in performance were observed at younger ages, in 2-back, in verbal rather than numerical stimuli and in girls compared to boys. Boys responded faster at baseline, while girls showed increased growth in 2-back numbers. Children with ADHD (Attention Deficit and Hyperactivity Disorder symptoms (15% of boys and 6% of girls had a lower working memory at baseline, but they showed similar cognitive growth trajectories in numbers variants of the task, as compared to children without ADHD symptoms. However, the age-related improvement in response speed was not observed in children with ADHD symptoms. Conclusions: Changes in n-back outcomes reflected developmental trajectories in one-year follow-up. The present results suggest that the repeated administration of this task can be used to study the factors that may alter the cognitive development during childhood.

Investigation of Back-Projection Uncertainties with M6 Earthquakes

Science.gov (United States)

Fan, W.; Shearer, P. M.

2017-12-01

We investigate possible biasing effects of inaccurate timing corrections on teleseismic P-wave back-projection imaging of large earthquake ruptures. These errors occur because empirically-estimated time shifts based on aligning P-wave first arrivals are exact only at the hypocenter and provide approximate corrections for other parts of the rupture. Using the Japan subduction zone as a test region, we analyze 46 M6-7 earthquakes over a ten-year period, including many aftershocks of the 2011 M9 Tohoku earthquake, performing waveform cross-correlation of their initial P-wave arrivals to obtain hypocenter timing corrections to global seismic stations. We then compare back-projection images for each earthquake using its own timing corrections with those obtained using the time corrections for other earthquakes. This provides a measure of how well sub-events can be resolved with back-projection of a large rupture as a function of distance from the hypocenter. Our results show that back-projection is generally very robust and that sub-event location errors average about 20 km across the entire study region ( 700 km). The back-projection coherence loss and location errors do not noticeably converge to zero even when the event pairs are very close (<20 km). This indicates that most of the timing differences are due to 3D structure close to each of the hypocenter regions, which limits the effectiveness of attempts to refine back-projection images using aftershock calibration, at least in this region.

Adolescent low back pain among secondary school students in ...

African Journals Online (AJOL)

ent-administered, validated questionnaire on low back pain in adolescents. Participants (Female: 298 ... affects public health6,8 and it is now being increasingly recognized that LBP in ..... back pain but are repetitive in nature. The finding of.

What low back pain is and why we need to pay attention.

Science.gov (United States)

Hartvigsen, Jan; Hancock, Mark J; Kongsted, Alice; Louw, Quinette; Ferreira, Manuela L; Genevay, Stéphane; Hoy, Damian; Karppinen, Jaro; Pransky, Glenn; Sieper, Joachim; Smeets, Rob J; Underwood, Martin

2018-03-20

Low back pain is a very common symptom. It occurs in high-income, middle-income, and low-income countries and all age groups from children to the elderly population. Globally, years lived with disability caused by low back pain increased by 54% between 1990 and 2015, mainly because of population increase and ageing, with the biggest increase seen in low-income and middle-income countries. Low back pain is now the leading cause of disability worldwide. For nearly all people with low back pain, it is not possible to identify a specific nociceptive cause. Only a small proportion of people have a well understood pathological cause-eg, a vertebral fracture, malignancy, or infection. People with physically demanding jobs, physical and mental comorbidities, smokers, and obese individuals are at greatest risk of reporting low back pain. Disabling low back pain is over-represented among people with low socioeconomic status. Most people with new episodes of low back pain recover quickly; however, recurrence is common and in a small proportion of people, low back pain becomes persistent and disabling. Initial high pain intensity, psychological distress, and accompanying pain at multiple body sites increases the risk of persistent disabling low back pain. Increasing evidence shows that central pain-modulating mechanisms and pain cognitions have important roles in the development of persistent disabling low back pain. Cost, health-care use, and disability from low back pain vary substantially between countries and are influenced by local culture and social systems, as well as by beliefs about cause and effect. Disability and costs attributed to low back pain are projected to increase in coming decades, in particular in low-income and middle-income countries, where health and other systems are often fragile and not equipped to cope with this growing burden. Intensified research efforts and global initiatives are clearly needed to address the burden of low back pain as a public

Energetic evaluation of high pressure PEM electrolyzer systems for intermediate storage of renewable energies

International Nuclear Information System (INIS)

Bensmann, B.; Hanke-Rauschenbach, R.; Peña Arias, I.K.; Sundmacher, K.

2013-01-01

Three pathways for high pressure hydrogen production by means of water electrolysis are energetically compared. Besides the two classic paths, comprising either the pressurization of the product gas (path I) or the mechanical pressurization of the feed water (path II), a third path is discussed. It involves the electrochemical co-compression during the electrolysis. The energetic evaluation is based on a uniform model description of the different hydrogen production pathways. It consists of integral, steady-state balances for energy, entropy and mass as well as a modern equation of state. From this the reversible energy demand is used to identify the inherent thermodynamic drawbacks of the pathways. The additional consideration of irreversibilities allows for the determination of efficiency losses due to device specific characteristics. For hydrogen delivery pressures of up to 40 bar the classical pathways are out-performed by path III. Since the hydrogen is already produced at elevated pressure this eliminates the need for an energy consuming mechanical hydrogen compression and spares the additional energy demand due to the oxygen pressurization. However, with increasing pressure differences the hydrogen back-diffusion strongly decreases the Faradaic efficiency of the asymmetric electrolyzer that has to be compensated by an additional energy supply

MSGD: Scalable back-end for indoor magnetic field-based GraphSLAM

OpenAIRE

Gao, C; Harle, Robert Keith

2017-01-01

Simultaneous Localisation and Mapping (SLAM) systems that recover the trajectory of a robot or mobile device are characterised by a front-end and back-end. The front-end uses sensor observations to identify loop closures; the back-end optimises the estimated trajectory to be consistent with these closures. The GraphSLAM framework formulates the back-end problem as a graph-based optimisation on a pose graph. This paper describes a back-end system optimised for very dense sequence-based lo...

Sensitization of the nociceptive system in patients with low back pain and sickness absence: Disc degeneration disease or pain syndrome

DEFF Research Database (Denmark)

Jensen, Ole Kudsk; Nielsen, Claus Vinther; Stengaard-Pedersen, Kristian

SENSITIZATION OF THE NOCICEPTIVE SYSTEM IN PATIENTS WITH LOW BACK PAIN AND SICKNESS ABSENCE O.K. Jensen1, C.V. Nielsen2, K. Stengaard-Pedersen3 1The Spine Center, Department of Internal Medicine, Region Hospital Silkeborg, 2Department of Clinical Social Medicine, University of Aarhus, and 3...... characterized by sensitization of the nociceptive system. Purpose: To assess sensitization of the nociceptive system in low back pain (LBP) patients by means of TP examination and measure of Pressure Pain Threshold (PPT) on the thumb nails. To search for associations between the number of TPs and structural...... = 1.35, p = 0.017) and mental distress (anxiety) in men (OR = 1.39, p = 0.003). After adjustment for age and sex, a positive association between LBP score and DDS was found only in patients with less than six TPs (OR = 1.21 (1.0-1.47), p = 0.043). Low PPT on the thumb nails was associated with DDS...

Back-to-back heavy quark pair production in semi-inclusive DIS

Science.gov (United States)

Zhang, Guang-Peng

2017-11-01

The one-loop correction to heavy quark pair back-to-back production in unpolarized semi-inclusive deep inelastic scattering is given in this work in the framework of transverse momentum dependent(TMD) factorization. Both unpolarized and linearly polarized TMD gluon distribution functions are taken into account. A subtraction method based on diagram expansion is used to get finite hard coefficients. It is found the soft and collinear divergences of one-loop amplitude is proportional to tree level ones and can be expressed through several basic scalar triangle and bubble integrals. The subtraction of these divergences is spin independent. Beyond tree level an additional soft factor related to final heavy quark pair must be added into the factorization formula. This soft factor affects the azimuthal angle distribution of virtual photon in a nonperturbative way. Integrating over virtual photon azimuthal angle we construct three weighted cross sections, which depend on only three additional integrated soft factors. These weighted cross sections can be used to extract linearly polarized gluon distribution function. In addition, lepton azimuthal angle is unintegrated in this work, which provides more observables. All hard coefficients relevant to lepton and virtual photon azimuthal angle distributions are given at one-loop level.

The association between a lifetime history of work-related low back injury and future low back pain: a population-based cohort study

DEFF Research Database (Denmark)

Nolet, Paul S; Kristman, Vicki L; Côté, Pierre

2016-01-01

effects of misclassification of the exposure by examining the association between a lifetime history of having taken time off work or performed light duties at work because of a work-related low back injury. Current evidence from cross-sectional studies suggests that individuals with a history of a work...... in September 1995. At baseline, participants were asked if they had ever injured their low back at work. The secondary analysis asked if they had ever had to take time off work or perform light duties at work because of a work-related low back injury. Prospective follow-up 6 and 12 months later, asked about....... We found an association between a history of work-related low back injury and the onset of troublesome LBP after controlling for gender (adjusted HRR = 2.24; 95 % CI 1.41–3.56). When covariates that may also be mediators of the association were added to the model, the effect estimate was attenuated...

Pressure pain sensitivity maps, self-reported musculoskeletal disorders and sickness absence among cleaners

DEFF Research Database (Denmark)

Binderup, Asbjørn Thalund; Holtermann, Andreas; Søgaard, Karen

2011-01-01

back regions (27 points). LTSA was defined as ten or more consecutive workdays with sick leave. RESULTS: The PPT maps revealed the spatial heterogeneity in mechanical sensitivity among cleaners. The level of pain in the neck and dominant shoulder and upper back within the last 7 days correlated......BACKGROUND: Pressure pain threshold mapping is a valuable method for the identification of distinct zones of mechanical pain sensitivity. Such approach was applied for the first time in relation to self-reported musculoskeletal disorders and long-term sickness absence (LTSA) within the last 12...... months among cleaners. METHODS: About 29 cleaners filled out a self-administered questionnaire regarding health, work-related measures and musculoskeletal disorders. Subsequently, PPTs were measured at (1) tibialis anterior (control location, 1 point), (2) the neck-shoulder (48 points) and (3) the low...

Suppression of Back-to-Back Hadron Pairs at Forward Rapidity in d+Au Collisions at √(sNN)=200 GeV

International Nuclear Information System (INIS)

Adare, A.; Ellinghaus, F.; Kinney, E.; Linden Levy, L. A.; Nagle, J. L.; Rosen, C. A.; Seele, J.; Wysocki, M.; Afanasiev, S.; Isupov, A.; Litvinenko, A.; Malakhov, A.; Peresedov, V.; Rukoyatkin, P.; Zolin, L.; Aidala, C.; Datta, A.; Ajitanand, N. N.; Alexander, J.; Chung, P.

2011-01-01

Back-to-back hadron pair yields in d+Au and p+p collisions at √(s NN )=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η| T , and η points to cold nuclear matter effects arising at high parton densities.

Is Interferential Current Before Pilates Exercises More Effective Than Placebo in Patients With Chronic Nonspecific Low Back Pain?: A Randomized Controlled Trial.

Science.gov (United States)

Franco, Katherinne Moura; Franco, Yuri Dos Santos; Oliveira, Naiane Bastos de; Miyamoto, Gisela Cristiane; Santos, Matheus Oliveira; Liebano, Richard Eloin; Cabral, Cristina Nunes

2017-02-01

To determine whether interferential current (IFC) before Pilates exercises is more effective than placebo in patients with chronic nonspecific low back pain. Two-arm randomized controlled trial, with a blinded assessor, and 6 months follow-up. Clinic of a school of physical therapy. The random sample consisted of patients (N=148) of both sexes, with age between 18 and 80 years and chronic nonspecific low back pain. In addition, participants were recruited by disclosure of the treatment in the media. Patients were allocated into 2 groups: active IFC + Pilates or placebo IFC + Pilates. In the first 2 weeks, patients were treated for 30 minutes with active or placebo IFC. In the following 4 weeks, 40 minutes of Pilates exercises were added after the application of the active or placebo IFC. A total of 18 sessions were offered during 6 weeks. The primary outcome measures were pain intensity, pressure pain threshold, and disability measured at 6 weeks after randomization. No significant differences were found between the groups for pain (0.1 points; 95% confidence interval, -0.9 to 1.0 points), pressure pain threshold (25.3kPa; 95% confidence interval, -4.4 to 55.0kPa), and disability (0.4 points; 95% confidence interval, -1.3 to 2.2). However, there was a significant difference between baseline and 6-week and 6-month follow-ups in the intragroup analysis for all outcomes (PPilates group. These findings suggest that active IFC before Pilates exercise is not more effective than placebo IFC with respect to the outcomes assessed in patients with chronic nonspecific low back pain. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Central sensitization in chronic low back pain: A narrative review.

Science.gov (United States)

Sanzarello, Ilaria; Merlini, Luciano; Rosa, Michele Attilio; Perrone, Mariada; Frugiuele, Jacopo; Borghi, Raffaele; Faldini, Cesare

2016-11-21

Low back pain is one of the four most common disorders in all regions, and the greatest contributor to disability worldwide, adding 10.7% of total years lost due to this health state. The etiology of chronic low back pain is, in most of the cases (up to 85%), unknown or nonspecific, while the specific causes (specific spinal pathology and neuropathic/radicular disorders) are uncommon. Central sensitization has been recently recognized as a potential pathophysiological mechanism underlying a group of chronic pain conditions, and may be a contributory factor for a sub-group of patients with chronic low back pain. The purposes of this narrative review are twofold. First, to describe central sensitization and its symptoms and signs in patients with chronic pain disorders in order to allow its recognition in patients with nonspecific low back pain. Second, to provide general treatment principles of chronic low back pain with particular emphasis on pharmacotherapy targeting central sensitization.

Making Sense of Low Back Pain and Pain-Related Fear.

Science.gov (United States)

Bunzli, Samantha; Smith, Anne; Schütze, Robert; Lin, Ivan; O'Sullivan, Peter

2017-09-01

Synopsis Pain-related fear is implicated in the transition from acute to chronic low back pain and the persistence of disabling low back pain, making it a key target for physical therapy intervention. The current understanding of pain-related fear is that it is a psychopathological problem, whereby people who catastrophize about the meaning of pain become trapped in a vicious cycle of avoidance behavior, pain, and disability, as recognized in the fear-avoidance model. However, there is evidence that pain-related fear can also be seen as a common-sense response to deal with low back pain, for example, when one is told that one's back is vulnerable, degenerating, or damaged. In this instance, avoidance is a common-sense response to protect a "damaged" back. While the fear-avoidance model proposes that when someone first develops low back pain, the confrontation of normal activity in the absence of catastrophizing leads to recovery, the pathway to recovery for individuals trapped in the fear-avoidance cycle is less clear. Understanding pain-related fear from a common-sense perspective enables physical therapists to offer individuals with low back pain and high fear a pathway to recovery by altering how they make sense of their pain. Drawing on a body of published work exploring the lived experience of pain-related fear in people with low back pain, this clinical commentary illustrates how Leventhal's common-sense model may assist physical therapists to understand the broader sense-making processes involved in the fear-avoidance cycle, and how they can be altered to facilitate fear reduction by applying strategies established in the behavioral medicine literature. J Orthop Sports Phys Ther 2017;47(9):628-636. Epub 13 Jul 2017. doi:10.2519/jospt.2017.7434.

Fitness, motor competence, and body composition are weakly associated with adolescent back pain.

Science.gov (United States)

Perry, Mark; Straker, Leon; O'Sullivan, Peter; Smith, Anne; Hands, Beth

2009-06-01

Cross-sectional survey. To assess the associations between adolescent back pain and fitness, motor competence, and body composition. Although deficits in physical fitness and motor control have been shown to relate to adult back pain, the evidence in adolescents is less clear. In this cross-sectional study, 1608 "Raine" cohort adolescents (mean age, 14 years) answered questions on lifetime, month, and chronic prevalence of back pain, and participated in a range of physical tests assessing aerobic capacity, muscle performance, flexibility, motor competence, and body composition.A history of any diagnosed back pain in the adolescent was obtained from the primary caregiver. After multivariate logistic regression analysis, increased likelihood of back pain in boys was associated with greater aerobic capacity, greater waist girth, and both reduced and greater flexibility. Back pain in girls was associated with greater abdominal endurance, reduced kinesthetic integration, and both reduced and greater back endurance. Lower likelihood of back pain was associated with greater bimanual dexterity in boys and greater lower extremity power in girls. Physical characteristics are commonly cited as important risk factors in back pain development. Although some factors were associated with adolescent back pain, and these differed between boys and girls, they made only a small contribution to logistic regression models for back pain. The results suggest future work should explore the interaction of multiple domains of risk factors (physical, lifestyle, and psychosocial) and subgroups of adolescent back pain, for whom different risk factors may be important.

Low back pain among nurses in Slovenian hospitals: cross-sectional study.

Science.gov (United States)

Skela-Savič, B; Pesjak, K; Hvalič-Touzery, S

2017-12-01

The study investigated the prevalence and factors predicting low back pain among nurses in Slovenian hospitals. The risk factors for low back pain are physical and psychosocial. Implementation of interventions for reducing low back pain calls for management support, accessible equipment, education, knowledge and risk assessment. Low back pain prevalence and incidence among healthcare workers is very high compared to the general population and is a strong risk factor for long-term sickness absence. A cross-sectional study design was utilized. We used validated instruments: Nordic Musculoskeletal Disorder Questionnaire, Stanford Presenteeism Scale and Perceived Stress Scale. The sample included 1744 nursing employees from 16 Slovenian hospitals, ranging from practical nurses, registered nurses, nurses with a bachelor's degree and those with a master's degree. Results revealed a prevalence of low back pain among 85.9% of respondents. Relevant risk factors included female gender, age, length of employment, years in current position, shift work and the number of nurses per shift. In the regression model, factors predicting low back pain included presenteeism with a negative effect on work, presenteeism and maintaining work productivity, inability to control daily life, number of nurses per shift and respondents' age. Future activities should be oriented towards eliminating or reducing risks for low back pain incidents and towards different strategies, guidelines and actions which empower individuals and provide knowledge to manage and prevent low back pain. Slovenian healthcare system planning needs a national strategy to successfully promote LBP preventive and controlling strategies. Management can plan preventive and curative measures to reduce low back pain prevalence among nursing personnel. Management should also implement policies reflecting research findings. © 2017 International Council of Nurses.

Herbal medicine for low back pain: a Cochrane review

NARCIS (Netherlands)

Gagnier, J.J.; van Tulder, M.W.; Berman, B.; Bombardier, C.

2007-01-01

STUDY DESIGN. A systematic review of randomized controlled trials. OBJECTIVES. To determine the effectiveness of herbal medicine compared with placebo, no intervention, or "standard/accepted/conventional treatments" for nonspecific low back pain. SUMMARY OF BACKGROUND DATA. Low back pain is a common

Meta-analysis: exercise therapy for nonspecific low back pain

NARCIS (Netherlands)

Hayden, J.A.; van Tulder, M.; Malmivaara, A.V.; Koes, B.W.

2005-01-01

BACKGROUND: Exercise therapy is widely used as an intervention in low back pain. OBJECTIVE: To evaluate the effectiveness of exercise therapy in adult nonspecific acute, subacute, and chronic low back pain versus no treatment and other conservative treatments. DATA SOURCES: MEDLINE, EMBASE,

Identifying Network Motifs that Buffer Front-to-Back Signaling in Polarized Neutrophils

Directory of Open Access Journals (Sweden)

Yanqin Wang

2013-05-01

Full Text Available Neutrophil polarity relies on local, mutual inhibition to segregate incompatible signaling circuits to the leading and trailing edges. Mutual inhibition alone should lead to cells having strong fronts and weak backs or vice versa. However, analysis of cell-to-cell variation in human neutrophils revealed that back polarity remains consistent despite changes in front strength. How is this buffering achieved? Pharmacological perturbations and mathematical modeling revealed a functional role for microtubules in buffering back polarity by mediating positive, long-range crosstalk from front to back; loss of microtubules inhibits buffering and results in anticorrelation between front and back signaling. Furthermore, a systematic, computational search of network topologies found that a long-range, positive front-to-back link is necessary for back buffering. Our studies suggest a design principle that can be employed by polarity networks: short-range mutual inhibition establishes distinct signaling regions, after which directed long-range activation insulates one region from variations in the other.

Field-scale forward and back diffusion through low-permeability zones

Science.gov (United States)

Yang, Minjune; Annable, Michael D.; Jawitz, James W.

2017-07-01

Understanding the effects of back diffusion of groundwater contaminants from low-permeability zones to aquifers is critical to making site management decisions related to remedial actions. Here, we combine aquifer and aquitard data to develop recommended site characterization strategies using a three-stage classification of plume life cycle based on the solute origins: aquifer source zone dissolution, source zone dissolution combined with back diffusion from an aquitard, and only back diffusion. We use measured aquitard concentration profile data from three field sites to identify signature shapes that are characteristic of these three stages. We find good fits to the measured data with analytical solutions that include the effects of advection and forward and back diffusion through low-permeability zones, and linearly and exponentially decreasing flux resulting from source dissolution in the aquifer. Aquifer contaminant time series data at monitoring wells from a mature site were well described using analytical solutions representing the combined case of source zone and back diffusion, while data from a site where the source had been isolated were well described solely by back diffusion. The modeling approach presented in this study is designed to enable site managers to implement appropriate remediation technologies at a proper timing for high- and low-permeability zones, considering estimated plume life cycle.

A comparison of muscle activation between back squats and belt squats.

Science.gov (United States)

Evans, Thomas W; McLester, Cherilyn N; Howard, Jonathan H; McLester, John R; Calloway, Jimmy P

2017-06-08

A machine belt squat is a piece of equipment designed to allow the performance of squats while loading weight on the lifter's hips using a belt. The purpose of this investigation was to determine if belt squats differ from back squats in activation of the primary movers, and to determine the predictive capabilities of back squat load, training status, and anthropometric data on belt squat load. Thirty-one participants (16 males and 15 females) completed anthropometric measurements, a demographic questionnaire, a familiarization visit, and two testing visits, completing a 5 repetition maximum test for back squat and belt squat. Surface electromyography was used to measure muscle activation for the left and right vastus medialis (VMO), vastus lateralis (VLO), rectus femoris (RF), and gluteus maximus (GM). Comparison of muscle activation between the two exercises showed significant differences in the left GM (back squat: 0.84 ± 0.45, belt squat: 0.69 ± 0.22, p=0.015) and right GM (back squat: 0.86 ± 0.45, belt squat: 0.71 ± 0.29, p=0.004). Regression analysis computed significant prediction equations for belt squat load for general population, males, females, and advanced lifters. Overall, results indicate that belt squats may significantly differ in GM activation from back squats. Back squat load, as well as other variables, may be effective in accurately estimating appropriate belt squat load. These findings may help to more appropriately program for training with machine belt squats as a back squat alternative.

Direct Measurement of the Mode O Turbulent Boundary Layer Wall Pressure and Wall Shear Stress Spectra Using Air-Backed and Oil-Filled Multichannel Wavenumber Filters

National Research Council Canada - National Science Library

Peloquin, Mark

1999-01-01

..., thin cylinder in an axial flow field. These measurements, processed as wavenumber-frequency spectra, were made with a multichannel array composed of an air-backed cylinder structure and a 32-channel aperture of PVDF film sensors having...

Pressure retarded osmosis for energy production: membrane materials and operating conditions.

Science.gov (United States)

Kim, H; Choi, J-S; Lee, S

2012-01-01

Pressure retarded osmosis (PRO) is a novel membrane process to produce energy. PRO has the potential to convert the osmotic pressure difference between fresh water (i.e. river water) and seawater to electricity. Moreover, it can recover energy from highly concentrated brine in seawater desalination. Nevertheless, relatively little research has been undertaken for fundamental understanding of the PRO process. In this study, the characteristics of the PRO process were examined using a proof-of-concept device. Forward osmosis (FO), reverse osmosis (RO), and nanofiltration (NF) membranes were compared in terms of flux rate and concentration polarization ratio. The results indicated that the theoretical energy production by PRO depends on the membrane type as well as operating conditions (i.e. back pressure). The FO membrane had the highest energy efficiency while the NF membrane had the lowest efficiency. However, the energy production rate was low due to high internal concentration polarization (ICP) in the PRO membrane. This finding suggests that the control of the ICP is essential for practical application of PRO for energy production.

The method for simultaneous extraction and back extraction in liquid three-phase system and equipment for simultaneous extraction and back extraction in liquid three-phase system

International Nuclear Information System (INIS)

Palyska, W.; Chmielewski, A.G.

1992-01-01

The method for simultaneous extraction and back extraction in liquid three-phase system has been worked out. The equipment designed for that process has been also subject of the patent. The interesting component is extracted first to intermediate phase consists of magnetic solvent keeping two extracting phases separately. The intermediate magnetic liquid has been kept in its position using a stable magnet maintained on the surface of the extraction vessel. Then the component pass from intermediate phase to the third phase as a result of back extraction. Mixing in the extraction and back extraction zones is organized by means of rotating shaft going along the whole apparatus. The extraction and back extraction processes occur simultaneously as a result of continuous flow of solvent in their zones. The single extraction back extraction facilities can be joined in larger batteries. 3 figs

Relationship between Teach-back and patient-centered communication in primary care pediatric encounters.

Science.gov (United States)

Badaczewski, Adam; Bauman, Laurie J; Blank, Arthur E; Dreyer, Benard; Abrams, Mary Ann; Stein, Ruth E K; Roter, Debra L; Hossain, Jobayer; Byck, Hal; Sharif, Iman

2017-07-01

We proposed and tested a theoretical framework for how use of Teach-back could influence communication during the pediatric clinical encounter. Audio-taped pediatric primary care encounters with 44 children with asthma were coded using the Roter Interaction Analysis System to measure patient-centered communication and affective engagement of the parent. A newly created Teach-back Loop Score measured the extent to which Teach-back occurred during the clinical encounter; parental health literacy was measured by Newest Vital Sign. Logistic regression was used to test the relationship between Teach-back and features of communication. Focus groups held separately with clinicians and parents elicited perceptions of Teach-back usefulness. Teach-back was used in 39% of encounters. Visits with Teach-back had more patient centered communication (p=0.01). Adjusting for parent health literacy, parent age, and child age, Teach-back increased the odds of both patient centered communication [proportional AOR (95% CI)=4.97 (4.47-5.53)]and negative affect [AOR (95% CI)=5.39 (1.68-17.31)]. Focus group themes common to clinicians and parents included: Teach-back is effective, could cause discomfort, should be used with children, and nurses should use it. Teach-back was associated with more patient-centered communication and increased affective engagement of parents. Standardizing Teach-back use may strengthen patient-centered communication. Copyright © 2017 Elsevier B.V. All rights reserved.

Correlations of hip mobility with degree of back pain and lumbar spinal mobility in chronic low-back pain patients.

Science.gov (United States)

Mellin, G

1988-06-01

Mobility of hips and lumbar spine were measured in 301 men and 175 women who were in employment but suffered from chronic or recurrent low-back pain. The degree of low-back pain (LBP) was assessed with a questionnaire. Hip flexion, extension, internal rotation, and hamstring flexibility in the men, and hip flexion and extension in the women had statistically significant negative correlations with LBP. Among the correlations between hip and lumbar spinal mobility, hip flexion and extension with lumbar rotation were strongest.

Minimizing Back Exchange in the Hydrogen Exchange-Mass Spectrometry Experiment

Science.gov (United States)

Walters, Benjamin T.; Ricciuti, Alec; Mayne, Leland; Englander, S. Walter

2012-12-01

The addition of mass spectrometry (MS) analysis to the hydrogen exchange (HX) proteolytic fragmentation experiment extends powerful HX methodology to the study of large biologically important proteins. A persistent problem is the degradation of HX information due to back exchange of deuterium label during the fragmentation-separation process needed to prepare samples for MS measurement. This paper reports a systematic analysis of the factors that influence back exchange (solution pH, ionic strength, desolvation temperature, LC column interaction, flow rates, system volume). The many peptides exhibit a range of back exchange due to intrinsic amino acid HX rate differences. Accordingly, large back exchange leads to large variability in D-recovery from one residue to another as well as one peptide to another that cannot be corrected for by reference to any single peptide-level measurement. The usual effort to limit back exchange by limiting LC time provides little gain. Shortening the LC elution gradient by 3-fold only reduced back exchange by ~2 %, while sacrificing S/N and peptide count. An unexpected dependence of back exchange on ionic strength as well as pH suggests a strategy in which solution conditions are changed during sample preparation. Higher salt should be used in the first stage of sample preparation (proteolysis and trapping) and lower salt (<20 mM) and pH in the second stage before electrospray injection. Adjustment of these and other factors together with recent advances in peptide fragment detection yields hundreds of peptide fragments with D-label recovery of 90 % ± 5 %.

Minimizing back exchange in the hydrogen exchange-mass spectrometry experiment.

Science.gov (United States)

Walters, Benjamin T; Ricciuti, Alec; Mayne, Leland; Englander, S Walter

2012-12-01

The addition of mass spectrometry (MS) analysis to the hydrogen exchange (HX) proteolytic fragmentation experiment extends powerful HX methodology to the study of large biologically important proteins. A persistent problem is the degradation of HX information due to back exchange of deuterium label during the fragmentation-separation process needed to prepare samples for MS measurement. This paper reports a systematic analysis of the factors that influence back exchange (solution pH, ionic strength, desolvation temperature, LC column interaction, flow rates, system volume). The many peptides exhibit a range of back exchange due to intrinsic amino acid HX rate differences. Accordingly, large back exchange leads to large variability in D-recovery from one residue to another as well as one peptide to another that cannot be corrected for by reference to any single peptide-level measurement. The usual effort to limit back exchange by limiting LC time provides little gain. Shortening the LC elution gradient by 3-fold only reduced back exchange by ~2%, while sacrificing S/N and peptide count. An unexpected dependence of back exchange on ionic strength as well as pH suggests a strategy in which solution conditions are changed during sample preparation. Higher salt should be used in the first stage of sample preparation (proteolysis and trapping) and lower salt (<20 mM) and pH in the second stage before electrospray injection. Adjustment of these and other factors together with recent advances in peptide fragment detection yields hundreds of peptide fragments with D-label recovery of 90% ± 5%.

Complementary and alternative therapies for back pain II.

Science.gov (United States)

Furlan, Andrea D; Yazdi, Fatemeh; Tsertsvadze, Alexander; Gross, Anita; Van Tulder, Maurits; Santaguida, Lina; Cherkin, Dan; Gagnier, Joel; Ammendolia, Carlo; Ansari, Mohammed T; Ostermann, Thomas; Dryden, Trish; Doucette, Steve; Skidmore, Becky; Daniel, Raymond; Tsouros, Sophia; Weeks, Laura; Galipeau, James

2010-10-01

Back and neck pain are important health problems with serious societal and economic implications. Conventional treatments have been shown to have limited benefit in improving patient outcomes. Complementary and Alternative Medicine (CAM) therapies offer additional options in the management of low back and neck pain. Many trials evaluating CAM therapies have poor quality and inconsistent results. To systematically review the efficacy, effectiveness, cost-effectiveness, and harms of acupuncture, spinal manipulation, mobilization, and massage techniques in management of back, neck, and/or thoracic pain. MEDLINE, Cochrane Central, Cochrane Database of Systematic Reviews, CINAHL, and EMBASE were searched up to 2010; unpublished literature and reference lists of relevant articles were also searched. study selection: All records were screened by two independent reviewers. Primary reports of comparative efficacy, effectiveness, harms, and/or economic evaluations from randomized controlled trials (RCTs) of the CAM therapies in adults (age ≥ 18 years) with back, neck, or thoracic pain were eligible. Non-randomized controlled trials and observational studies (case-control, cohort, cross-sectional) comparing harms were also included. Reviews, case reports, editorials, commentaries or letters were excluded. Two independent reviewers using a predefined form extracted data on study, participants, treatments, and outcome characteristics. 265 RCTs and 5 non-RCTs were included. Acupuncture for chronic nonspecific low back pain was associated with significantly lower pain intensity than placebo but only immediately post-treatment (VAS: -0.59, 95 percent CI: -0.93, -0.25). However, acupuncture was not different from placebo in post-treatment disability, pain medication intake, or global improvement in chronic nonspecific low back pain. Acupuncture did not differ from sham-acupuncture in reducing chronic non-specific neck pain immediately after treatment (VAS: 0.24, 95 percent CI: -1

The relationship between back pain and lead apron use in radiologists

Energy Technology Data Exchange (ETDEWEB)

Moore, B.; vanSonnenberg, E.; Casola, G.; Novelline, R.A. (Department of Radiology, University of California, San Diego (Unites States))

1992-01-01

Anecdotal experience has suggested that back pain in radiologists may result from extensive wearing of lead aprons. To investigate this possibility, the authors sent questionnaires to 688 radiologists in various subspecialties whose use of lead aprons varied from none to moderate to extensive. The questionnaire included both objective items that quantitated apron use and back pain and subjective items that asked, for example, if the respondent believed that lead aprons were responsible for his or her back pain. They received 236 responses (34% response rate). Objective data from those radiologists who had experienced no back pain before wearing a lead apron (179 radiologists, 26% of those surveyed) were tabulated; respondents were grouped according to age, time spent wearing a lead apron, and degree of back pain. Odds ratios were calculated. Answers to subjective questions for all respondents were tabulated. Back pain was reported by 52% of those who estimated their lead apron use at greater than or equal to 10 hr per week, the mean response, as opposed to 46% of those who wore lead aprons fewer than 10 hr a week. These and related results were not statistically significant. Our study does not prove that wearing a lead apron is a significant risk factor for the development of back pain.

The relationship between back pain and lead apron use in radiologists

International Nuclear Information System (INIS)

Moore, B.; vanSonnenberg, E.; Casola, G.; Novelline, R.A.

1992-01-01

Anecdotal experience has suggested that back pain in radiologists may result from extensive wearing of lead aprons. To investigate this possibility, the authors sent questionnaires to 688 radiologists in various subspecialties whose use of lead aprons varied from none to moderate to extensive. The questionnaire included both objective items that quantitated apron use and back pain and subjective items that asked, for example, if the respondent believed that lead aprons were responsible for his or her back pain. They received 236 responses (34% response rate). Objective data from those radiologists who had experienced no back pain before wearing a lead apron (179 radiologists, 26% of those surveyed) were tabulated; respondents were grouped according to age, time spent wearing a lead apron, and degree of back pain. Odds ratios were calculated. Answers to subjective questions for all respondents were tabulated. Back pain was reported by 52% of those who estimated their lead apron use at greater than or equal to 10 hr per week, the mean response, as opposed to 46% of those who wore lead aprons fewer than 10 hr a week. These and related results were not statistically significant. Our study does not prove that wearing a lead apron is a significant risk factor for the development of back pain

Prevalence and causes of back pain syndromes in children

Directory of Open Access Journals (Sweden)

A.A. Smirnova

2014-01-01

Full Text Available We present a review of literature devoted to epidemiology, and the nosological and syndromal structure of back pain in children. The data of our own study of school-aged children with back pain are presented. The structure of back pain syndromes in 105 children has been analyzed using the medical aid appealability data. The results of a comprehensive clinical and instrumental study demonstrated that the children mostly had lumbosacral pain (52.4% of cases; neck pain was observed in 29.5% of cases; while thoracic pain syndromes were observed in 18.1% of cases. Congenital defect of the connective tissue was diagnosed in 16.19% of children; congenital abnormalities of the spine, in 15.2%; scoliosis (idiopathic and secondary, in 8.6%; and Scheuermann-Mau's disease, in 5.71%. The conclusion has been made about the high prevalence of back pain in schoolchildren. Muscular tonic syndromes were prevailing in the clinical structure in children; radicular syndromes were less frequent. Musculoskeletal disorders were the main causes of back pain. Congenital defect of the connective tissue was often observed, which was revealed as functional instability of the vertebral motor segment, spondylolisthesis due to weak ligaments, and disc protrusions. Congenital abnormalities of the spine, scoliosis, and Scheuermann-Mau' disease were observed less often. 

Real-time determination of fringe pattern frequencies: An application to pressure measurement

Science.gov (United States)

Sciammarella, Cesar A.; Piroozan, Parham

2007-05-01

Retrieving information in real time from fringe patterns is a topic of a great deal of interest in scientific and engineering applications of optical methods. This paper presents a method for fringe frequency determination based on the capability of neural networks to recognize signals that are similar but not identical to signals used to train the neural network. Sampled patterns are generated by calibration and stored in memory. Incoming patterns are analyzed by a back-propagation neural network at the speed of the recording device, a CCD camera. This method of information retrieval is utilized to measure pressures on a boundary layer flow. The sensor combines optics and electronics to analyze dynamic pressure distributions and to feed information to a control system that is capable to preserve the stability of the flow.

Acute Low Back Pain? Do Not Blame the Weather-A Case-Crossover Study.

Science.gov (United States)

Beilken, Keira; Hancock, Mark J; Maher, Chris G; Li, Qiang; Steffens, Daniel

2017-06-01

To investigate the influence of various weather parameters on the risk of developing a low back pain (LBP) episode. Case-crossover study. Primary care clinics in Sydney, Australia. 981 participants with a new episode of acute LBP. Weather parameters were obtained from the Australian Bureau of Meteorology. Odds ratios (OR) and 95% confidence intervals (95% CI) were derived comparing two exposure variables in the case window-(1) the average of the weather variable for the day prior to pain onset and (2) the change in the weather variable from 2 days prior to 1 day prior to pain onset-with exposures in two control windows (1 week and 1 month before the case window). The weather parameters of precipitation, humidity, wind speed, wind gust, wind direction, and air pressure were not associated with the onset of acute LBP. For one of the four analyses, higher temperature slightly increased the odds of pain onset. Common weather parameters that had been previously linked to musculoskeletal pain, such as precipitation, humidity, wind speed, wind gust, wind direction, and air pressure, do not increase the risk of onset for LBP. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Study of air entrainment in high pressure spray: optics diagnostics and application to the Diesel injection; Etude de l'entrainement d'air dans un spray haute pression: diagnostics optiques et application a l'injection diesel

Energy Technology Data Exchange (ETDEWEB)

Arbeau, A.

2004-12-15

The actual development of the engine must reply to a will of fuel consumption reduction and to norms more and more strict concerning the pollutant emissions. Although the Diesel engines are efficient, the NO{sub x} and particle emissions mainly come from the existence of wealthy fuel zone preventing an optimal combustion. Therefore, the air / fuel mixing preparation, highly controlled by the air entrainment in spray, is essential. In this context, we have developed metrological tools in order to analyse the air entrainment mechanism in a dense spray. The Particle Image Velocimetry (PIV) technique is first applied to a conical spray with an injection pressure less than 100 bars to study the air entrainment in spray. A transfer of the methodologies allows then the characterisation and the understanding of the air entrainment mechanism in high pressure full spray (injection pressure less than 1600 bars) type Diesel one. The influence of injection parameters (injection pressure and back pressure) on the mixing rate is studied. The increase of the injection pressure from 800 to 1600 bars implies an increase of the mixing rate of 60 %. Moreover, the thermodynamic conditions of the ambient air, simulated by the chamber back pressure, widely favours the mixing rate. Actually, this latter increases of 350 % when the chamber back pressure varies from 1 to 7 bars. The experimental results do not follow classical laws of air entrainment in one-phase flow jet with variable density, but are in good agreement with an integral model for air entrainment in an axisymmetric full spray. Finally, the Fluorescence Particle Image Velocimetry (FPIV) is introduced in order to extend the PIV application field in dense two-phase flows. (author)

Neuroscience education in addition to trigger point dry needling for the management of patients with mechanical chronic low back pain: A preliminary clinical trial.

Science.gov (United States)

Téllez-García, Mario; de-la-Llave-Rincón, Ana I; Salom-Moreno, Jaime; Palacios-Ceña, Maria; Ortega-Santiago, Ricardo; Fernández-de-Las-Peñas, César

2015-07-01

The objective of the current study was to determine the short-term effects of trigger point dry needling (TrP-DN) alone or combined with neuroscience education on pain, disability, kinesiophobia and widespread pressure sensitivity in patients with mechanical low back pain (LBP). Twelve patients with LBP were randomly assigned to receive either TrP-DN (TrP-DN) or TrP-DN plus neuroscience education (TrP-DN + EDU). Pain intensity (Numerical Pain Rating Scale, 0-10), disability (Roland-Morris Disability Questionnaire-RMQ-, Oswestry Low Back Pain Disability Index-ODI), kinesiophobia (Tampa Scale of Kinesiophobia-TSK), and pressure pain thresholds (PPT) over the C5-C6 zygapophyseal joint, transverse process of L3 vertebra, second metacarpal, and tibialis anterior muscle were collected at baseline and 1-week after the intervention. Patients treated with TrP-DN + EDU experienced a significantly greater reduction of kinesiophobia (P = 0.008) and greater increases in PPT over the transverse process of L3 (P = 0.049) than those patients treated only with TrP-DN. Both groups experienced similar decreases in pain, ODI and RMQ, and similar increases in PPT over the C5/C6 joint, second metacarpal, and tibialis anterior after the intervention (all, P > 0.05). The results suggest that TrP-DN was effective for improving pain, disability, kinesiophobia and widespread pressure sensitivity in patients with mechanical LBP at short-term. The inclusion of a neuroscience educational program resulted in a greater improvement in kinesiophobia. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prevalence of Low Back Pain among Adolescent Students in a ...

African Journals Online (AJOL)

Oyewoleye

KEYWORDS: low back pain, prevalence, adolescent students, Nigeria. INTRODUCTION. Low-back ... content validity of the questionnaire was assessed among ten experienced ... in the orthopaedic ward and out-patient physiotherapy clinic.

Effect of the back surface topography on the efficiency in silicon solar cells

International Nuclear Information System (INIS)

Guo Aijuan; Ye Famin; Feng Shimeng; Guo Lihui; Ji Dong

2009-01-01

Different processes are used on the back surface of silicon wafers to form cells falling into three groups: textured, planar, and sawed-off pyramid back surface. The characteristic parameters of the cells, I SC , V OC , FF, Pm, and E ff , are measured. All these parameters of the planar back surface cells are the best. The FF, Pm, and E ff of sawed-off pyramid back surface cells are superior to textured back surface cells, although I SC and V OC are lower. The parasitic resistance is analyzed to explain the higher FF of the sawed-off pyramid back surface cells. The cross-section scanning electron microscopy (SEM) pictures show the uniformity of the aluminum-silicon alloy, which has an important effect on the back surface recombination velocity and the ohmic contact. The measured value of the aluminum back surface field thickness in the SEM picture is in good agreement with the theoretical value deduced from the Al-Si phase diagram. It is shown in an external quantum efficiency (EQE) diagram that the planar back surface has the best response to a wavelength between 440 and 1000 nm and the sawed-off back surface has a better long wavelength response.

13 CFR 120.612 - Loans eligible to back Certificates.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Loans eligible to back Certificates. 120.612 Section 120.612 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Secondary Market Certificates § 120.612 Loans eligible to back Certificates. (a) Pool Certificates...

The Pilates® Method in the treatment of lower back pain

Directory of Open Access Journals (Sweden)

Marcelo Henrique Oliveira de Vasconcellos

Full Text Available Introduction The Pilates® method incorporates a number of the guidelines recommended for therapeutic exercises considered to be effective in the treatment of chronic lower back pain, such as the contraction of the transversus abdominis and multifidus muscles, associated with breathing, while taking into account the individual characteristics of patients. Objective To assess the effects of the Pilates® method on the treatment of lower back pain. Method This systematic review includes papers published from 2000 to 2010 in the BIREME, LILACS, MEDLINE and SciELO databases. The keywords used were spinal stabilization, Pilates®, and back pain and their equivalents in Portuguese. Results Imbalance among the trunk’s agonist-antagonist muscles and the ineffective activation of the transversus abdominis are risk factors for the onset of lower back pain that can be mitigated with the practice of Pilates®-based exercises. Conclusion The method has clinical effects similar to those obtained with traditional stabilization exercises and Back School exercises in the treatment of chronic lower back pain and are considered more satisfactory than conservative treatments.

Brunkow exercises and low back pain

Directory of Open Access Journals (Sweden)

Emela Mujić Skikić

2004-11-01

Full Text Available Brunkow exercises starting with dynamic contraction of hands and feet with fixed point on the wrist or/and heal. Dynamic contraction from the beginning, transferring through kinetic chain, leads to isometric contraction of the group of muscles, which has to be included in the exercise. Starting positions determine the group of muscles to be trained. The purpose of this study is to investigate influence of Brunkow exercises on spinal motion improvement and pain relief and to evaluate use of Brunkow exercises, as a routine method for lower back pain in Physical Medicine and Rehabilitation Centres. Thirty-four patients with symptoms of low back pain were included in study. Patients received a mean of 14.9 treatments with standard deviation of 8.96. All patients were assessed before and after the treatment for spinal mobility and flexibility as well as pain intensity. All parameters for spinal movements showed statistically significant improvement in patients with low back pain who practiced Brunkow exercise program at the end of treatment in relations to pre-treatment values, with significant difference of p<0.01 for all motions. Pain was reduced on VAS for X=1.,7 with S.D. 1.97. Difference Test was t=6.020 with significant difference p<0.01. Flexibility of spine increased, so average difference in values before and after treatment for Shober test was 0.5 cm with SD 0.65. Difference test was t=3.794 with significant difference p<0.01. Brunkow exercises for low back pain are beneficial treatment for increasing flexibility and mobility of spine and improving the pain.

Back end of the fuel cycle

International Nuclear Information System (INIS)

Wolfe, B.; Lambert, R.W.

1975-01-01

At present, that portion of the nuclear fuel cycle involving reprocessing, waste management, and mixed-oxide fuel fabrication is in an unsettled state. Government regulatory requirements with respect to all aspects of the back end of the fuel cycle are still being formulated, and there is little positive experience on the operation of commercial reprocessing or mixed-oxide fabrication plants. In view of this unsettled situation, it will be difficult to meet the reprocessing and mixed-oxide fabrication needs of the next decade in the pattern previously anticipated. The costs in the back end of the fuel cycle are much higher than had been anticipated several years ago, a situation similar to that of almost all large endeavors in this country. On the other hand, the added costs are small relative to total power costs and do not affect the economic advantage of nuclear power as compared to other power sources. A rough economic analysis indicates that the question for the back end of the fuel cycle has changed from one of optimizing profitability to one of determining the most economic disposition of spent fuel. Long-term spent fuel storage is a practical and economically acceptable way to provide time for determining a sound course of action for the back end of the fuel cycle. Indeed, if one could count on a breeder economy before the end of the century, one possible course of action is to store light-water fuel until the plutonium can be used in breeders. However, for philosophical as well as practical reasons, it is important that the uncertainties in the course of action should be resolved as quickly as possible. Long-term storage should not be an excuse to delay resolution of the basic questions. (U.S.)

Back reaction and the local cosmological expansion rate

CERN Document Server

Geshnizjani, G

2002-01-01

We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single field. We analyze back reaction both in a matter-dominated Universe and in a phase of scalar field-driven chaotic inflation. In both cases, we find that the leading infrared terms contributing to the back reaction vanish when the local expansion rate is measured at a fixed value of the matter field which is used as a clock, whereas they do not appear to vanish if the expansion rate is evaluated at a fixed value of the background time. We discuss possible implications for more realistic models with a more complicated matter sector.

Lower back pain in nurses working in home care: linked to work-family conflict, emotional dissonance, and appreciation?

Science.gov (United States)

Elfering, Achim; Häfliger, Evelyne; Celik, Zehra; Grebner, Simone

2018-07-01

In industrial countries home care services for elderly people living in the community are growing rapidly. Home care nursing is intensive and the nurses often suffer from musculoskeletal pain. Time pressure and job control are job-related factors linked to the risk of experiencing lower back pain (LBP) and LBP-related work impairment. This survey investigated whether work-family conflict (WFC), emotional dissonance and being appreciated at work have incremental predictive value. Responses were obtained from 125 home care nurses (63% response rate). Multiple linear regression showed that emotional dissonance and being appreciated at work predicted LBP intensity and LBP-related disability independently of time pressure and job control. WFC was not a predictor of LBP-related disability in multiple regression analyses despite a zero-order correlation with it. Redesigning the working pattern of home care nurses to reduce the emotional demands and improve appreciation of their work might reduce the incidence of LBP in this group.

Factors that impact functional performance of elderly with low back pain

Directory of Open Access Journals (Sweden)

Flora Pereira Guerra

Full Text Available Abstract Introduction: Low back pain is a common condition among older adults and an important cause of disability. Objective: To evaluate the relationship between functional performance of older adults with low back pain and the following variables: sociodemographic and clinical factors, self-perceived health and back pain beliefs. Methods: A cross-sectional study that used data from the Back Complaints in the Elders international consortium. Information about sociodemographic factors (sex, age, marital status, formal education, clinical factors (intensity and frequency of pain, comorbidities, self-perceived health, back pain beliefs and functional performance (measured by the disability component of the Late Life Function and Disability Instrument - LLFDI were collected through self-report. 191 older adults above 60 years with a new episode of back complaints who did not have any cognitive disorder, visual or hearing impairment, or motor disabilities participated in the study. A bivariate analysis was conducted between each independent variable and each outcome. Associations with p < 0.20 were selected for the multiple linear regression analysis, which was carried out for each LLFDI domain. Results: The multiple regression coefficients of determination were significant despite the modest magnitude. The variables related to functional performance were back beliefs, self-perceived health, formal education, pain frequency and marital status. Conclusion: These results may contribute to the expansion of health professionals’ work in the therapeutic approach of low back pain, broadening its focus beyond clinical aspects in order to value beliefs of older adults and their self-perceived health.

Core strength training for patients with chronic low back pain.

Science.gov (United States)

Chang, Wen-Dien; Lin, Hung-Yu; Lai, Ping-Tung

2015-03-01

[Purpose] Through core strength training, patients with chronic low back pain can strengthen their deep trunk muscles. However, independent training remains challenging, despite the existence of numerous core strength training strategies. Currently, no standardized system has been established analyzing and comparing the results of core strength training and typical resistance training. Therefore, we conducted a systematic review of the results of previous studies to explore the effectiveness of various core strength training strategies for patients with chronic low back pain. [Methods] We searched for relevant studies using electronic databases. Subsequently, we evaluated their quality by analyzing the reported data. [Results] We compared four methods of evaluating core strength training: trunk balance, stabilization, segmental stabilization, and motor control exercises. According to the results of various scales and evaluation instruments, core strength training is more effective than typical resistance training for alleviating chronic low back pain. [Conclusion] All of the core strength training strategies examined in this study assist in the alleviation of chronic low back pain; however, we recommend focusing on training the deep trunk muscles to alleviate chronic low back pain.

Capacitance Estimation for DC-link Capacitors in a Back-to-Back Converter Based on Artificial Neural Network Algorithm

DEFF Research Database (Denmark)

Soliman, Hammam Abdelaal Hammam; Wang, Huai; Blaabjerg, Frede

2016-01-01

of the aforementioned challenges and shortcomings. In this paper, a pure software condition monitoring method based on Artificial Neural Network (ANN) algorithm is proposed. The implemented ANN estimates the capacitance of the dc-link capacitor in a back-to-back converter. The error analysis of the estimated results......The reliability of dc-link capacitors in power electronic converters is one of the critical aspects to be considered in modern power converter design. The observation of their ageing process and the estimation of their health status have been an attractive subject for the industrial field and hence...

Disability associated with low back pain in Mulago Hospital ...

African Journals Online (AJOL)

Background: Low back pain is sufficiently disabling and a common cause of disability particularly during the productive middle years of adult life. Disability implies interference with daily activities. Objective: To assess and document the disability associated with low back pain in terms of sick leave days, interference with ...

Disability associated with low back pain in Mulago Hospital ...

African Journals Online (AJOL)

204 patients with mechanical back pain were enrolled in the study, after screening all consecutive new adult patients referred with low back pain as the major complaint. A validated modified Oswestry instrument was used to collect data. Nine daily activities: sleep, sex, lifting, traveling, social and recreational activities, ...

Second order bounce back boundary condition for the lattice Boltzmann fluid simulation

International Nuclear Information System (INIS)

Kim, In Chan

2000-01-01

A new bounce back boundary method of the second order in error is proposed for the lattice Boltzmann fluid simulation. This new method can be used for the arbitrarily irregular lattice geometry of a non-slip boundary. The traditional bounce back boundary condition for the lattice Boltzmann simulation is of the first order in error. Since the lattice Boltzmann method is the second order scheme by itself, a boundary technique of the second order has been desired to replace the first order bounce back method. This study shows that, contrary to the common belief that the bounce back boundary condition is unilaterally of the first order, the second order bounce back boundary condition can be realized. This study also shows that there exists a generalized bounce back technique that can be characterized by a single interpolation parameter. The second order bounce back method can be obtained by proper selection of this parameter in accordance with the detailed lattice geometry of the boundary. For an illustrative purpose, the transient Couette and the plane Poiseuille flows are solved by the lattice Boltzmann simulation with various boundary conditions. The results show that the generalized bounce back method yields the second order behavior in the error of the solution, provided that the interpolation parameter is properly selected. Coupled with its intuitive nature and the ease of implementation, the bounce back method can be as good as any second order boundary method

Wildlife use of back channels associated with islands on the Ohio River

Science.gov (United States)

Zadnik, A.K.; Anderson, James T.; Wood, P.B.; Bledsoe, K.

2009-01-01

The back channels of islands on the Ohio River are assumed to provide habitat critical for several wildlife species. However, quantitative information on the wildlife value of back channels is needed by natural resource managers for the conservation of these forested islands and embayments in the face of increasing shoreline development and recreational boating. We compared the relative abundance of waterbirds, turtles, anurans, and riparian furbearing mammals during 2001 and 2002 in back and main channels of the Ohio River in West Virginia. Wood ducks (Aix sponsa), snapping turtles (Chelydra serpentina), beavers (Castor canadensis), and muskrats (Ondatra zibethicus) were more abundant in back than main channels. Spring peepers (Pseudacris crucifer) and American toads (Bufo americanus) occurred more frequently on back than main channels. These results provide quantitative evidence that back channels are important for several wildlife species. The narrowness of the back channels, the protection they provide from the main current of the river, and their ability to support vegetated shorelines and woody debris, are characteristics that appear to benefit these species. As a conservation measure for important riparian wildlife habitat, we suggest limiting building of piers and development of the shoreline in back channel areas. ?? 2009, The Society of Wetland Scientists.

Validity and reliability of the Turkish version of the pressure ulcer prevention knowledge assessment instrument.

Science.gov (United States)

Tulek, Zeliha; Polat, Cansu; Ozkan, Ilknur; Theofanidis, Dimitris; Togrol, Rifat Erdem

2016-11-01

Sound knowledge of pressure ulcers is important to enable good prevention. There are limited instruments assessing pressure ulcer knowledge. The Pressure Ulcer Prevention Knowledge Assessment Instrument is among the scales of which psychometric properties have been studied rigorously and reflects the latest evidence. This study aimed to evaluate the validity and reliability of the Turkish version of the Pressure Ulcer Prevention Knowledge Assessment Instrument (PUPKAI-T), an instrument that assesses knowledge of pressure ulcer prevention by using multiple-choice questions. Linguistic validity was verified through front-to-back translation. Psychometric properties of the instrument were studied on a sample of 150 nurses working in a tertiary hospital in Istanbul, Turkey. The content validity index of the translated instrument was 0.94, intra-class correlation coefficients were between 0.37 and 0.80, item difficulty indices were between 0.21 and 0.88, discrimination indices were 0.20-0.78, and the Kuder Richardson for the internal consistency was 0.803. The PUPKAI-T was found to be a valid and reliable tool to evaluate nurses' knowledge on pressure ulcer prevention. The PUPKAI-T may be a useful tool for determining educational needs of nurses on pressure ulcer prevention. Copyright © 2016 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

In vivo measurement of lower back deformations with Fourier-transform profilometry

International Nuclear Information System (INIS)

Hanafi, Abdelmalek; Gharbi, Tijani; Cornu, Jean-Yves

2005-01-01

Through the variation of their cross sections, the in vivo response of lower back muscles to low loading in an upright seated posture is explored by the Fourier-transform profilometry technique. The maximization of its sensitivity allows us to reach an adequate resolution for the evaluation of low-back displacements. Refinements of the fringe pattern analysis permit the minimization of errors. The experiments show an asymmetric distribution of the displacement during head rotation movements. Significant contribution of the lower back to grasping exertions is also observed. These results are thought to be useful for early defect detection in the lower back

Mediators of Yoga and Stretching for Chronic Low Back Pain

Directory of Open Access Journals (Sweden)

Karen J. Sherman

2013-01-01

Full Text Available Although yoga is an effective treatment for chronic low back pain, little is known about the mechanisms responsible for its benefits. In a trial comparing yoga to intensive stretching and self-care, we explored whether physical (hours of back exercise/week, cognitive (fear avoidance, body awareness, and self-efficacy, affective (psychological distress, perceived stress, positive states of mind, and sleep, and physiological factors (cortisol, DHEA mediated the effects of yoga or stretching on back-related dysfunction (Roland-Morris Disability Scale (RDQ. For yoga, 36% of the effect on 12-week RDQ was mediated by increased self-efficacy, 18% by sleep disturbance, 9% by hours of back exercise, and 61% by the best combination of all possible mediators (6 mediators. For stretching, 23% of the effect was mediated by increased self-efficacy, 14% by days of back exercise, and 50% by the best combination of all possible mediators (7 mediators. In open-ended questions, ≥20% of participants noted the following treatment benefits: learning new exercises (both groups, relaxation, increased awareness, and the benefits of breathing (yoga, benefits of regular practice (stretching. Although both self-efficacy and hours of back exercise were the strongest mediators for each intervention, compared to self-care, qualitative data suggest that they may exert their benefits through partially distinct mechanisms.

Back-contacted back-junction silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Mangersnes, Krister

2010-10-15

Conventional silicon solar cells have a front-side contacted emitter. Back-contacted back-junction (BC-BJ) silicon solar cells, on the other hand, have both the complete metallization and the active diffused regions of both polarities on the backside. World-record efficiencies have already been demonstrated for this type of cell design in production, both on cell and module level. However, the production of these cells is both complex and costly, and a further cost reduction in fabrication is needed to make electricity from BC-BJ silicon solar cells cost-competitive with electricity on the grid ('grid-parity'). During the work with this thesis, we have investigated several important issues regarding BC-BJ silicon solar cells. The aim has been to reduce production cost and complexity while at the same time maintaining, or increasing, the already high conversion efficiencies demonstrated elsewhere. This has been pursued through experimental work as well as through numerical simulations and modeling. Six papers are appended to this thesis, two of which are still under review in scientific journals. In addition, two patents have been filed based on the work presented herein. Experimentally, we have focused on investigating and optimizing single, central processing steps. A laser has been the key processing tool during most of the work. We have used the same laser both to structure the backside of the cell and to make holes in a double-layer of passivating amorphous silicon and silicon oxide, where the holes were opened with the aim of making local contact to the underlying silicon. The processes developed have the possibility of using a relatively cheap and industrially proven laser and obtain results better than most state-of-the-art laser technologies. During the work with the laser, we also developed a thermodynamic model that was able to predict the outcome from laser interaction with amorphous and crystalline silicon. Alongside the experimental work, we

An ultrasound-based liquid pressure measurement method in small diameter pipelines considering the installation and temperature.

Science.gov (United States)

Li, Xue; Song, Zhengxiang

2015-04-09

Liquid pressure is a key parameter for detecting and judging faults in hydraulic mechanisms, but traditional measurement methods have many deficiencies. An effective non-intrusive method using an ultrasound-based technique to measure liquid pressure in small diameter (less than 15 mm) pipelines is presented in this paper. The proposed method is based on the principle that the transmission speed of an ultrasonic wave in a Kneser liquid correlates with liquid pressure. Liquid pressure was calculated using the variation of ultrasonic propagation time in a liquid under different pressures: 0 Pa and X Pa. In this research the time difference was obtained by an electrical processing approach and was accurately measured to the nanosecond level through a high-resolution time measurement module. Because installation differences and liquid temperatures could influence the measurement accuracy, a special type of circuit called automatic gain control (AGC) circuit and a new back propagation network (BPN) model accounting for liquid temperature were employed to improve the measurement results. The corresponding pressure values were finally obtained by utilizing the relationship between time difference, transient temperature and liquid pressure. An experimental pressure measurement platform was built and the experimental results confirm that the proposed method has good measurement accuracy.

Rising prevalence of back pain in Austria: considering regional disparities.

Science.gov (United States)

Großschädl, Franziska; Stolz, Erwin; Mayerl, Hannes; Rásky, Éva; Freidl, Wolfgang; Stronegger, Willibald J

2016-01-01

Back pain is the most common form of musculoskeletal conditions and leads to high health care costs. Information about geographic variations in highly prevalent diseases/disorders represents important implications for public health planning to face structural challenges. The present study aims to investigate regional trends in the prevalence of back pain and the role of obesity and social inequalities among Austrian adults. A secondary data analysis based on five nationally representative cross-sectional surveys (1973-2007) was carried out (N = 178,818). Back pain was measured as self-reported presence. Obesity (BMI ≥ 30 kg/m²) was adjusted for self-report bias. For the regional analyses, Austria was divided into Western, Central and Eastern Austria. A relative index of inequality (RII) was computed to quantify the extent of social inequality. A continuous rise in back pain prevalence was observed in the three regions and among all investigated subgroups. In 2007 the age-standardised prevalence was similar in Central (36.9 %), Western (35.2 %) and Eastern Austria (34.3 %). The absolute change in back pain prevalence was highest among obese subjects in Central Austria (women: + 29.8 %, men: + 32.5 %). RIIs were unstable during the study period and in 2007 highest in Eastern Austria. Variation and trends in back pain are not attributable to geographic variation in Austria: an assumed East-West gradient in Austria has not been confirmed. Nevertheless our study confirms that back pain dramatically increased in all Austrian regions and investigated subgroups. This worrying trend should be further monitored and public health interventions should be implemented increasingly, especially among obese women and men.

Reducing the pressure drag of a D-shaped bluff body using linear feedback control

Science.gov (United States)

Dalla Longa, L.; Morgans, A. S.; Dahan, J. A.

2017-12-01

The pressure drag of blunt bluff bodies is highly relevant in many practical applications, including to the aerodynamic drag of road vehicles. This paper presents theory revealing that a mean drag reduction can be achieved by manipulating wake flow fluctuations. A linear feedback control strategy then exploits this idea, targeting attenuation of the spatially integrated base (back face) pressure fluctuations. Large-eddy simulations of the flow over a D-shaped blunt bluff body are used as a test-bed for this control strategy. The flow response to synthetic jet actuation is characterised using system identification, and controller design is via shaping of the frequency response to achieve fluctuation attenuation. The designed controller successfully attenuates integrated base pressure fluctuations, increasing the time-averaged pressure on the body base by 38%. The effect on the flow field is to push the roll-up of vortices further downstream and increase the extent of the recirculation bubble. This control approach uses only body-mounted sensing/actuation and input-output model identification, meaning that it could be applied experimentally.

Influence of the mechanical properties of sputtered Mo solar cell back contacts on laser scribing

Energy Technology Data Exchange (ETDEWEB)

Schultz, Christof; Schuele, Manuel; Quaschning, Volker; Stegemann, Bert; Fink, Frank [University of Applied Sciences (HTW) Berlin, Wilhelminenhofstr. 75A, 12459 Berlin (Germany); Endert, Heinrich [Newport Spectra-Physics GmbH, Ruhlsdorfer Strasse 95, 14532 Stahnsdorf (Germany); Bonse, Joern [BAM Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany); Rau, Bjoern; Schlatmann, Rutger [PVcomB - Competence Centre Thin-Film and Nanotechnology for Photovoltaics Berlin, Schwarzschildstr. 3, 12489 Berlin (Germany)

2012-07-01

In thin-film photovoltaics complete laser structuring of the solar modules is aimed to perform appropriate monolithic serial interconnection. We have studied the laser ablation behavior of sputtered molybdenum back contacts for chalcopyrite solar cells. The properties of these Mo layer are sensitive to the sputter conditions. The process pressure influences the mechanical layer properties and, thus, contributes directly to the quality of the laser scribes. Precise, reliable and reproducible laser scribing requires the proper adaptation of the laser parameters to the material properties. In our study it was achieved by comprehensive analysis of the laser matter interaction and by detailed determination of the ablation thresholds as a function of the Mo layer thickness and ductility for different laser wavelengths and pulse durations, accompanied by thermal modeling.

The Scope of Back Pain in Navy Helicopter Pilots

Science.gov (United States)

2011-03-01

Environmental Medicine 55: 556–7. 40 Frymoyer, J. W., & Cats- Baril W. L. (1991). An overview of the incidences and costs of low back pain. Orthopedic...between individuals. Does back pain affect safety of flight? Frymoyer and Cats- Baril (1991) reported that in the civilian community, at any given

Frequency Selective Surfaces for extended Bandwidth backing reflector functions

NARCIS (Netherlands)

Pasian, M.; Neto, A.; Monni, S.; Ettorre, M.; Gerini, G.

2008-01-01

This paper deals with the use of Frequency Selective Surfaces (FSS) to increase the Efficiency × Bandwidth product in Ultra-Wide Band (UWB) antenna arrays whose efficiency is limited by the front-to-back ratio. If the backing reflector is realized in one metal plane solution its location will be

Ocena aktywności mięśnia poprzecznego brzucha z wykorzystaniem urządzenia Pressure Bio-feedback Stabilizer u osób z dolegliwościami bólowymi kręgosłupa w odcinku lędźwiowo-krzyżowym = Assessment of transverse abdominal muscle activity with the use of Pressure Bio-Feedback Stabilizer among people with low back pain

Directory of Open Access Journals (Sweden)

Bartosz Kochański

2016-07-01

ęśnia poprzecznego brzucha z wykorzystaniem urządzenia Pressure Bio-Feedback Stabilizer jest dobry.     Abstract Introduction: Transverse abdominal muscle plays important role in spine stabilization, researches show a correlation between this muscle activity and physical pain and health ailments of low back. The aim of this thesis: 1.Assessment and comparison of Transverse abdominal muscle  activity with the use of Pressure Bio-Feedback Stabilizer among people suffering from physical pain and health ailments of low back and among people who do not suffer from these ailments. 2. Description of level of consensus of two therapists’ assessment of Transverse abdominal muscle activity examination with the use of Pressure Bio-Feedback Stabilizer Materials and methods: The research was conducted among a group of 50 people age between 28,36, 28 women and 22 men. The examined were divided into two groups: group 1- 25 people (12 women and 13 men and control group- 25 people (16 women and 9 men. Group 1 consist of people suffering from physical pain and health ailments of lower part of the spine who currently suffer for at least 3 months. Group 2 (control group consist of people who do not suffer from physical paints and health ailments in the lower part of the spine for at least 6 months. Results: Incorrect transverse abdominal muscle activation was observed among people with physical pain and health ailments in the lower part of the spine. Statistical analysis showed significant differences between two examined groups in transverse abdominal muscle activity- p<0,05. Index of consistency ICC for two therapists examining transverse abdominal muscle activity with the use of Pressure Bio-Feedback Stabilizer equals 0.82. Conclusions: 1. Incorrect transverse abdominal muscle activity was observed among people with physical pain in the lumbar part of the spine. 2. Index of consistency of assessment for two therapist examining transverse abdominal muscle activity with the use of Pressure Bio

Back pain's association with vertebral end-plate signal changes in sciatica.

Science.gov (United States)

el Barzouhi, Abdelilah; Vleggeert-Lankamp, Carmen L A M; van der Kallen, Bas F; Lycklama à Nijeholt, Geert J; van den Hout, Wilbert B; Koes, Bart W; Peul, Wilco C

2014-02-01

Patients with sciatica frequently experience disabling back pain. One of the proposed causes for back pain is vertebral end-plate signal changes (VESC) as visualized by magnetic resonance imaging (MRI). To report on VESC findings, changes of VESC findings over time, and the correlation between VESC and disabling back pain in patients with sciatica. A randomized clinical trial with 1 year of follow-up. Patients with 6 to 12 weeks of sciatica who participated in a multicenter, randomized clinical trial comparing an early surgery strategy with prolonged conservative care with surgery if needed. Patients were assessed by means of the 100-mm visual analog scale (VAS) for back pain (with 0 representing no pain and 100 the worst pain ever experienced) at baseline and 1 year. Disabling back pain was defined as a VAS score of at least 40 mm. Patients underwent MRI both at baseline and after 1 year follow-up. Presence and change of VESC was correlated with disabling back pain using chi-square tests and logistic regression analysis. At baseline, 39% of patients had disabling back pain. Of the patients with VESC at baseline, 40% had disabling back pain compared with 38% of the patients with no VESC (p=.67). The prevalence of type 1 VESC increased from 1% at baseline to 35% 1 year later in the surgical group compared with an increase from 3% to 11% in the conservative group. The prevalence of type 2 VESC decreased from 40% to 29% in the surgical group while remaining almost stable in the conservative group at 41%. The prevalence of disabling back pain at 1 year was 12% in patients with no VESC at 1 year, 16% in patients with type 1 VESC, 11% in patients with type 2 VESC, and 3% in patients with both types 1 and 2 VESC (p=.36). Undergoing surgery was associated with increase in the extent of VESC (odds ratio [OR], 8.6; 95% confidence interval [CI], 4.7-15.7; psciatica was highly associated with the development of VESC after 1 year. However, in contrast with the intuitive feeling

Die-back of Phragmites australis in European wetlands: an overview of the European Research Programme on Reed Die-Back and Progression (1993-1994)

NARCIS (Netherlands)

Van der Putten, W.H.

1997-01-01

Reed (Phragmites australis (Cav.) Trin. ex Steudel) is one of the dominant plant species in European land-water ecotones. During the past decades reed belts have died back, especially in central and eastern Europe. The aim of the European Research Programme on Reed Die-back and Progression (EUREED),

Non-invasive measurements of pulse pressure variation and stroke volume variation in anesthetized patients using the Nexfin blood pressure monitor.

Science.gov (United States)

Stens, Jurre; Oeben, Jeroen; Van Dusseldorp, Ab A; Boer, Christa

2016-10-01

Nexfin beat-to-beat arterial blood pressure monitoring enables continuous assessment of hemodynamic indices like cardiac index (CI), pulse pressure variation (PPV) and stroke volume variation (SVV) in the perioperative setting. In this study we investigated whether Nexfin adequately reflects alterations in these hemodynamic parameters during a provoked fluid shift in anesthetized and mechanically ventilated patients. The study included 54 patients undergoing non-thoracic surgery with positive pressure mechanical ventilation. The provoked fluid shift comprised 15° Trendelenburg positioning, and fluid responsiveness was defined as a concomitant increase in stroke volume (SV) >10 %. Nexfin blood pressure measurements were performed during supine steady state, Trendelenburg and supine repositioning. Hemodynamic parameters included arterial blood pressure (MAP), CI, PPV and SVV. Trendelenburg positioning did not affect MAP or CI, but induced a decrease in PPV and SVV by 3.3 ± 2.8 and 3.4 ± 2.7 %, respectively. PPV and SVV returned back to baseline values after repositioning of the patient to baseline. Bland-Altman analysis of SVV and PPV showed a bias of -0.3 ± 3.0 % with limits of agreement ranging from -5.6 to 6.2 %. The SVV was more superior in predicting fluid responsiveness (AUC 0.728) than the PVV (AUC 0.636), respectively. The median bias between PPV and SVV was different for patients younger [-1.5 % (-3 to 0)] or older [+2 % (0-4.75)] than 55 years (P < 0.001), while there were no gender differences in the bias between PPV and SVV. The Nexfin monitor adequately reflects alterations in PPV and SVV during a provoked fluid shift, but the level of agreement between PPV and SVV was low. The SVV tended to be superior over PPV or Eadyn in predicting fluid responsiveness in our population.

Pressure-Sensitive Paints Advance Rotorcraft Design Testing

Science.gov (United States)

2013-01-01

The rotors of certain helicopters can spin at speeds as high as 500 revolutions per minute. As the blades slice through the air, they flex, moving into the wind and back out, experiencing pressure changes on the order of thousands of times a second and even higher. All of this makes acquiring a true understanding of rotorcraft aerodynamics a difficult task. A traditional means of acquiring aerodynamic data is to conduct wind tunnel tests using a vehicle model outfitted with pressure taps and other sensors. These sensors add significant costs to wind tunnel testing while only providing measurements at discrete locations on the model's surface. In addition, standard sensor solutions do not work for pulling data from a rotor in motion. "Typical static pressure instrumentation can't handle that," explains Neal Watkins, electronics engineer in Langley Research Center s Advanced Sensing and Optical Measurement Branch. "There are dynamic pressure taps, but your costs go up by a factor of five to ten if you use those. In addition, recovery of the pressure tap readings is accomplished through slip rings, which allow only a limited amount of sensors and can require significant maintenance throughout a typical rotor test." One alternative to sensor-based wind tunnel testing is pressure sensitive paint (PSP). A coating of a specialized paint containing luminescent material is applied to the model. When exposed to an LED or laser light source, the material glows. The glowing material tends to be reactive to oxygen, explains Watkins, which causes the glow to diminish. The more oxygen that is present (or the more air present, since oxygen exists in a fixed proportion in air), the less the painted surface glows. Imaged with a camera, the areas experiencing greater air pressure show up darker than areas of less pressure. "The paint allows for a global pressure map as opposed to specific points," says Watkins. With PSP, each pixel recorded by the camera becomes an optical pressure

The influence of fat infiltration of back extensor muscles on osteoporotic vertebral fractures.

Science.gov (United States)

So, Kwang-Young; Kim, Dae-Hee; Choi, Dong-Hyuk; Kim, Choong-Young; Kim, Jeong-Seok; Choi, Yong-Soo

2013-12-01

Retrospective study. To investigate the influence of fat infiltration at low back extensor muscles on osteoporotic vertebral fracture. In persons with stronger back muscles, the risk of osteoporotic vertebral fractures will likely be lower than in those persons with weaker back muscles. However, the degree of influence of fat infiltration of the back extensor muscle on osteoporotic vertebral fracture remains controversial. Two hundred and thirty-seven patients who had undergone lumbar spine magnetic resonance imaging and bone mineral density (BMD) were enrolled in this study. The amount of low back extensor muscle was determined using the pseudocoloring technique on an axial view of the L3 level. The patients were divided into two groups: osteoporotic vertebral fracture group (group A) and non-fracture group (group B). The amount of low back extensor muscle is compared with BMD, degenerative change of disc, osteophyte grade of facet joint and promontory angle to reveal the association between these factors. A negative correlation is found between age and the amount of low back extensor muscle (p=0.001). The amount of low back extensor muscle in group A and group B was 60.3%±14.5% and 64.2%±9.3% respectively, thus showing a significantly smaller amount of low back extensor muscle in the osteoporotic vertebral fracture group (p=0.015). Fat infiltration of low back extensor muscle was increased in osteoporotic vertebral fracture patients. Therefore, fat infiltration of low back extensor muscle in an elderly person may be a risk factor of osteoporotic vertebral fracture.

Short-circuit current improvement in thin cells with a gridded back contact

Science.gov (United States)

Giuliano, M.; Wohlgemuth, J.

1980-01-01

The use of gridded back contact on thin silicon solar cells 50 micrometers was investigated. An unexpected increase in short circuit current of almost 10 percent was experienced for 2 cm x 2 cm cells. Control cells with the standard continuous contact metallization were fabricated at the same time as the gridded back cells with all processes identical up to the formation of the back contact. The gridded back contact pattern was delineated by evaporation of Ti-Pd over a photo-resist mask applied to the back of the wafer; the Ti-Pd film on the controls was applied in the standard fashion in a continuous layer over the back of the cell. The Ti-Pd contacts were similarly applied to the front of the wafer, and the grid pattern on both sides of the cell was electroplated with 8-10 micrometers of silver.

Comparison of MRI-defined back muscles volume between patients with ankylosing spondylitis and control patients with chronic back pain: age and spinopelvic alignment matched study.

Science.gov (United States)

Bok, Doo Hee; Kim, Jihye; Kim, Tae-Hwan

2017-02-01

To compare MRI-defined back muscle volume between AS patients and age, and spinopelvic alignment matched control patients with chronic back pain. 51 male patients with AS were enrolled. Age and spinopelvic alignment matched controls (male) were found among non-AS patients with chronic back pain. After matching procedure, fully matched controls were found in 31 of 51 AS patients (60.8%), who represent AS patients without deformity. However, matched controls were not found in 20 of 51 AS patients (39.2%), who represent AS patients with deformity. MRI parameters of back muscle (paraspinal muscle and psoas muscle) at L4/5 disc level including cross-sectional area (CSA) and fat-free cross-sectional area (FCSA) were compared between AS patients and matched controls. Covariates, including BMI, self-reported physical activity, and the presence of chronic disease, which can influence back muscle volume, were also investigated. There were no statistical differences in age, body mass index, score of back pain (NRS), and spinopelvic alignment, and physical activity between matched AS patients and control patients except for duration of back pain. All MRI parameters for paraspinal muscle volume in matched AS patients (without deformity) were significantly less than those of control patients, and significantly larger than those of non-matched AS patients (with deformity). Body size adjusted MRI parameters (relative CSA and relative FCSA) of paraspinal muscle showed strong correlations with lumbar lordosis and sacral slope. Such relationship between paraspinal muscle and spinopelvic parameters remained significant even after multivariate adjustment. AS patients without deformity already have decreased paraspinal muscle volume compared with age and spinopelvic alignment matched non-AS patients with chronic back pain. Such decrease in paraspinal muscle volume was significantly associated with kyphotic deformity of AS patients even after multivariate adjustment. Although the result

Tc-DMSA (V) imaging for subacute back pain

International Nuclear Information System (INIS)

Baldey, A.; Salehi, N.; Thomas, C.; Schlict, S.; Lichtenstein, M.

1997-01-01

Full text: Background: Low back pain is a common disabling illness in the Western world creating $25 billion medical costs in the USA alone. The overall outcome of back pain has not been shown to be influenced by the currently available treatments. Diagnostic techniques are also imprecise. Some back pain may be due to minor currently undetectable ligamentous tears which generate a scarring fibrotic reaction. Aim: To detect minor ligamentous tears and ultimately assess steroid injection treatment using scintigraphic techniques. Methods: Technetium [valency (5)] dimercaptosuccinic acid [ 99m Tc (V) DMSA] is a radiopharmaceutical which has been demonstrated to accumulate in fibrotic tissues 2- Technetium-99m (V) DMSA single photon emission computed tomographic (SPECT) scans were performed in ten patients with subacute (2-12 months duration) back pain. These scans were compared to SPECT bone scans also performed in these patients. Results: One patient was excluded post imaging due to likely infection or tumour. Of the nine patients remaining, five showed lesions presumed to be due to healing scars. Hence new abnormalities are detectable by this technique. Conclusion: Accrual is continuing but definitive results will not be available until the clinical results of scan directed steroid injections are evaluated

Spotlight on topographical pressure pain sensitivity maps: a review

Directory of Open Access Journals (Sweden)

Alburquerque-Sendín F

2018-01-01

Full Text Available Francisco Alburquerque-Sendín,1 Pascal Madeleine,2 César Fernández-de-las-Peñas,3 Paula Rezende Camargo,4 Tania Fátima Salvini4 1Department of Socio-Sanitary Sciences, Radiology and Physical Medicine, Universidad de Córdoba, Córdoba, Spain; 2Physical Activity and Human Performance Group, SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark; 3Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, Universidad Rey Juan Carlos, Madrid, Spain; 4Department of Physical Therapy, Federal University of São Carlos, São Carlos, SP, Brazil Abstract: Mechanical hyperalgesia defined as decreased pressure pain thresholds (PPTs is commonly associated with pain. In this narrative review, we report the current state of the art within topographical pressure sensitivity maps. Such maps are based on multiple PPT assessments. The PPTs are assessed by an a priori defined grid with special focus on both spatial and temporal summation issues. The grid covers the muscle or the body region of interest using absolute or relative values determined from anatomical landmarks or anthropometric values. The collected PPTs are interpolated by Shepard or Franke and Nielson interpolation methods to create topographical pressure sensitivity maps. This new imaging technique has proven to be valuable in various disciplines including exercise physiology, neurology, physical therapy, occupational medicine, oncology, orthopedics, and sport sciences. The reviewed papers have targeted different body regions like the scalp, low back, neck–shoulder, and upper and lower extremities. The maps have delineated spatial heterogeneity in the pressure pain sensitivity underlining the different extents of pressure pain hyperalgesia in both experimentally induced and disease-associated pain conditions. Furthermore, various intervention studies have proven the utility of topographical pressure pain

Paschen-Back effect in dyonium

International Nuclear Information System (INIS)

Akers, D.

1987-01-01

A formulation of the Pashen-Back effect in dyonium is discussed to explain the recent evidence for a magnetic monopole of mass 2397 MeV and Dirac charge g = (137/2)e. The masses for isospin I = 0 mesons are estimated and compared with experiment