WorldWideScience

Sample records for hand numerous studies

  1. A natural approach to convey numerical digits using hand activity recognition based on hand shape features

    Science.gov (United States)

    Chidananda, H.; Reddy, T. Hanumantha

    2017-06-01

    This paper presents a natural representation of numerical digit(s) using hand activity analysis based on number of fingers out stretched for each numerical digit in sequence extracted from a video. The analysis is based on determining a set of six features from a hand image. The most important features used from each frame in a video are the first fingertip from top, palm-line, palm-center, valley points between the fingers exists above the palm-line. Using this work user can convey any number of numerical digits using right or left or both the hands naturally in a video. Each numerical digit ranges from 0 to9. Hands (right/left/both) used to convey digits can be recognized accurately using the valley points and with this recognition whether the user is a right / left handed person in practice can be analyzed. In this work, first the hand(s) and face parts are detected by using YCbCr color space and face part is removed by using ellipse based method. Then, the hand(s) are analyzed to recognize the activity that represents a series of numerical digits in a video. This work uses pixel continuity algorithm using 2D coordinate geometry system and does not use regular use of calculus, contours, convex hull and datasets.

  2. How Deep Is Your SNARC? Interactions Between Numerical Magnitude, Response Hands, and Reachability in Peripersonal Space

    Directory of Open Access Journals (Sweden)

    Johannes Lohmann

    2018-05-01

    Full Text Available Spatial, physical, and semantic magnitude dimensions can influence action decisions in human cognitive processing and interact with each other. For example, in the spatial-numerical associations of response code (SNARC effect, semantic numerical magnitude facilitates left-hand or right-hand responding dependent on the small or large magnitude of number symbols. SNARC-like interactions of numerical magnitudes with the radial spatial dimension (depth were postulated from early on. Usually, the SNARC effect in any direction is investigated using fronto-parallel computer monitors for presentation of stimuli. In such 2D setups, however, the metaphorical and literal interpretation of the radial depth axis with seemingly close/far stimuli or responses are not distinct. Hence, it is difficult to draw clear conclusions with respect to the contribution of different spatial mappings to the SNARC effect. In order to disentangle the different mappings in a natural way, we studied parametrical interactions between semantic numerical magnitude, horizontal directional responses, and perceptual distance by means of stereoscopic depth in an immersive virtual reality (VR. Two VR experiments show horizontal SNARC effects across all spatial displacements in traditional latency measures and kinematic response parameters. No indications of a SNARC effect along the depth axis, as it would be predicted by a direct mapping account, were observed, but the results show a non-linear relationship between horizontal SNARC slopes and physical distance. Steepest SNARC slopes were observed for digits presented close to the hands. We conclude that spatial-numerical processing is susceptible to effector-based processes but relatively resilient to task-irrelevant variations of radial-spatial magnitudes.

  3. How Deep Is Your SNARC? Interactions Between Numerical Magnitude, Response Hands, and Reachability in Peripersonal Space.

    Science.gov (United States)

    Lohmann, Johannes; Schroeder, Philipp A; Nuerk, Hans-Christoph; Plewnia, Christian; Butz, Martin V

    2018-01-01

    Spatial, physical, and semantic magnitude dimensions can influence action decisions in human cognitive processing and interact with each other. For example, in the spatial-numerical associations of response code (SNARC) effect, semantic numerical magnitude facilitates left-hand or right-hand responding dependent on the small or large magnitude of number symbols. SNARC-like interactions of numerical magnitudes with the radial spatial dimension (depth) were postulated from early on. Usually, the SNARC effect in any direction is investigated using fronto-parallel computer monitors for presentation of stimuli. In such 2D setups, however, the metaphorical and literal interpretation of the radial depth axis with seemingly close/far stimuli or responses are not distinct. Hence, it is difficult to draw clear conclusions with respect to the contribution of different spatial mappings to the SNARC effect. In order to disentangle the different mappings in a natural way, we studied parametrical interactions between semantic numerical magnitude, horizontal directional responses, and perceptual distance by means of stereoscopic depth in an immersive virtual reality (VR). Two VR experiments show horizontal SNARC effects across all spatial displacements in traditional latency measures and kinematic response parameters. No indications of a SNARC effect along the depth axis, as it would be predicted by a direct mapping account, were observed, but the results show a non-linear relationship between horizontal SNARC slopes and physical distance. Steepest SNARC slopes were observed for digits presented close to the hands. We conclude that spatial-numerical processing is susceptible to effector-based processes but relatively resilient to task-irrelevant variations of radial-spatial magnitudes.

  4. Hand osteoarthritis: Clinical and imaging study

    African Journals Online (AJOL)

    Abir Naguib

    2011-09-09

    Sep 9, 2011 ... Methods: This study was carried out on thirty patients with primary hand OA, and fifteen healthy subjects .... history about their hand condition including morning stiffness, ..... They found the US method of direct visualiza-.

  5. HUMAN HAND STUDY FOR ROBOTIC EXOSKELETON DELVELOPMENT

    Directory of Open Access Journals (Sweden)

    BIROUAS Flaviu Ionut

    2016-11-01

    Full Text Available This paper will be presenting research with application in the rehabilitation of hand motor functions by the aid of robotics. The focus will be on the dimensional parameters of the biological human hand from which the robotic system will be developed. The term used for such measurements is known as anthropometrics. The anthropometric parameters studied and presented in this paper are mainly related to the angular limitations of the finger joints of the human hand.

  6. HUMAN HAND STUDY FOR ROBOTIC EXOSKELETON DELVELOPMENT

    OpenAIRE

    BIROUAS Flaviu Ionut; NILGESZ Arnold

    2016-01-01

    This paper will be presenting research with application in the rehabilitation of hand motor functions by the aid of robotics. The focus will be on the dimensional parameters of the biological human hand from which the robotic system will be developed. The term used for such measurements is known as anthropometrics. The anthropometric parameters studied and presented in this paper are mainly related to the angular limitations of the finger joints of the human hand.

  7. Hand function evaluation: a factor analysis study.

    Science.gov (United States)

    Jarus, T; Poremba, R

    1993-05-01

    The purpose of this study was to investigate hand function evaluations. Factor analysis with varimax rotation was used to assess the fundamental characteristics of the items included in the Jebsen Hand Function Test and the Smith Hand Function Evaluation. The study sample consisted of 144 subjects without disabilities and 22 subjects with Colles fracture. Results suggest a four factor solution: Factor I--pinch movement; Factor II--grasp; Factor III--target accuracy; and Factor IV--activities of daily living. These categories differentiated the subjects without Colles fracture from the subjects with Colles fracture. A hand function evaluation consisting of these four factors would be useful. Such an evaluation that can be used for current clinical purposes is provided.

  8. Constraint Study for a Hand Exoskeleton: Human Hand Kinematics and Dynamics

    Directory of Open Access Journals (Sweden)

    Fai Chen Chen

    2013-01-01

    Full Text Available In the last few years, the number of projects studying the human hand from the robotic point of view has increased rapidly, due to the growing interest in academic and industrial applications. Nevertheless, the complexity of the human hand given its large number of degrees of freedom (DoF within a significantly reduced space requires an exhaustive analysis, before proposing any applications. The aim of this paper is to provide a complete summary of the kinematic and dynamic characteristics of the human hand as a preliminary step towards the development of hand devices such as prosthetic/robotic hands and exoskeletons imitating the human hand shape and functionality. A collection of data and constraints relevant to hand movements is presented, and the direct and inverse kinematics are solved for all the fingers as well as the dynamics; anthropometric data and dynamics equations allow performing simulations to understand the behavior of the finger.

  9. Numerical studies on divertor experiments

    International Nuclear Information System (INIS)

    Ueda, N.; Itoh, K.; Itoh, S.-I.; Tanaka, M.; Hasegawa, M.; Shoji, T.; Sugihara, M.

    1988-04-01

    Numerical analysis on the divertor experiments such as JFT-2M tokamak is made by use of the two-dimensional time-dependent simulation code. The plasma in the scrape-off layer (SOL) and divertor region is solved for the given particle and heat sources from the main plasma, Γ p and Q T . Effect of the direction of the toroidal magnetic field is studied. It is found that the heat flux which is proportional to b vector x ∇T i has influences on the divertor plasmas, but has a small effect on the parameters on the midplane in the framework of the fluid model. Parameter survey on Γ p and Q T is made. The transient response of the SOL/divertor plasma to the sudden change of Γ p and Q T is studied. Time delay in the SOL and divertor region is calculated. (author)

  10. Numerical study of turbulent diffusion

    International Nuclear Information System (INIS)

    McCoy, M.G.

    1975-01-01

    The problem of the numerical simulation of turbulent diffusion is studied. The two-dimensional velocity fields are assumed to be incompressible, homogeneous and stationary, and they are represented as stochastic processes. A technique is offered which creates velocity fields accurately representing the input statistics once a two point correlation function or an energy spectrum is given. Various complicated energy spectra may be represented utilizing this model. The program is then used to extract information concerning Gaussian diffusion processes. Various theories of other workers are tested including Taylor's classical representation of dispersion for times long compared with the Lagrangian correlation time. Also, a study is made of the relation between the Lagrangian and the Eulerian correlation function and a hypothesis is advanced and successfully tested. Questions concerning the relation between small eddies and the energy spectrum are considered. A criterion is advanced and successfully tested to decide whether small scale flow can be detected within the large eddies for any given spectrum. A method is developed to determine whether this small scale motion is in any sense periodic. Finally, the relation between two particle dispersion and the energy spectrum is studied anew and various theories are tested

  11. Numerical MHD study for plasmoid instability in uniform resistivity

    Science.gov (United States)

    Shimizu, Tohru; Kondoh, Koji; Zenitani, Seiji

    2017-11-01

    The plasmoid instability (PI) caused in uniform resistivity is numerically studied with a MHD numerical code of HLLD scheme. It is shown that the PI observed in numerical studies may often include numerical (non-physical) tearing instability caused by the numerical dissipations. By increasing the numerical resolutions, the numerical tearing instability gradually disappears and the physical tearing instability remains. Hence, the convergence of the numerical results is observed. Note that the reconnection rate observed in the numerical tearing instability can be higher than that of the physical tearing instability. On the other hand, regardless of the numerical and physical tearing instabilities, the tearing instability can be classified into symmetric and asymmetric tearing instability. The symmetric tearing instability tends to occur when the thinning of current sheet is stopped by the physical or numerical dissipations, often resulting in the drastic changes in plasmoid chain's structure and its activity. In this paper, by eliminating the numerical tearing instability, we could not specify the critical Lundquist number Sc beyond which PI is fully developed. It suggests that Sc does not exist, at least around S = 105.

  12. HandTutor™ enhanced hand rehabilitation after stroke--a pilot study.

    Science.gov (United States)

    Carmeli, Eli; Peleg, Sara; Bartur, Gadi; Elbo, Enbal; Vatine, Jean-Jacques

    2011-12-01

    This study assessed the potential therapeutic benefi t of using HandTutor™ in combination with traditional rehabilitation in a post-stroke sub-acute population. The study compares an experimental group receiving traditional therapy combined with HandTutorTM treatment, against a control group receiving only traditional therapy. An assessor-blinded, randomized controlled pilot trial, was conducted in the Reuth rehabilitation unit in Israel. Thirty-one stroke patients in the sub-acute phase, were randomly assigned to one of the two groups (experimental or control) in sets of three. The experimental group (n = 16) underwent a hand rehabilitation programme using the HandTutorTM combined with traditional therapy. The control group (n = 15) received only traditional therapy. The treatment schedules for both groups were of similar duration and frequency. Improvements were evaluated using three indicators: 1) The Brunnström-Fugl-Meyer (FM) test, 2) the Box and Blocks (B&B) test and 3) improvement parameters as determined by the HandTutorTM software. Following 15 consecutive treatment sessions, a signifi cant improvement was observed within the experimental group (95% confi dence intervals) compared with the control group: B&B p = 0.015; FM p = 0.041, HandTutor™ performance accuracy on x axis and performance accuracy on y axis p stroke hand function rehabilitation.

  13. Gyrotactic trapping: A numerical study

    Science.gov (United States)

    Ghorai, S.

    2016-04-01

    Gyrotactic trapping is a mechanism proposed by Durham et al. ["Disruption of vertical motility by shear triggers formation of thin Phytoplankton layers," Science 323, 1067-1070 (2009)] to explain the formation of thin phytoplankton layer just below the ocean surface. This mechanism is examined numerically using a rational model based on the generalized Taylor dispersion theory. The crucial role of sedimentation speed in the thin layer formation is demonstrated. The effects of variation in different parameters on the thin layer formation are also investigated.

  14. Contact pressure measurement in hand tool evaluation studies

    NARCIS (Netherlands)

    Kuijt-Evers, L.F.M.; Bosch, T.

    2006-01-01

    In hand tool evaluation studies, several objective measurements are used. Grip force distribution and grip force are important as they give feedback about the force which has to be performed with the hand on the handle. A measurement technique -which is related to grip force measurement- is contact

  15. Can Disability Studies and Psychology Join Hands?

    Science.gov (United States)

    Olkin, Rhoda; Pledger, Constance

    2003-01-01

    Although the field of disabilities studies incorporates psychology within its interdisciplinary purview, it embodies a distinct perspective consonant with the new paradigm of disability. Although psychology has begun embracing diversity, disability remains marginalized. Examines the foundational ideas of disability studies, training in disability…

  16. Numerical studies of the linear theta pinch

    International Nuclear Information System (INIS)

    Brackbill, J.U.; Menzel, M.T.; Barnes, D.C.

    1975-01-01

    Aspects of several physical problems associated with linear theta pinches were studied using recently developed numerical methods for the solution of the nonlinear equations for time-dependent magnetohydrodynamic flow in two- and three-dimensions. The problems studied include the propagation of end-loss produced rarefaction waves, the flow produced in a proposed injection experiment geometry, and the linear growth and nonlinear saturation of instabilities in rotating plasmas, all in linear geometries. The studies illustrate how numerical computations aid in flow visualization, and how the small amplitude behavior and nonlinear fate of plasmas in unstable equilibria can be connected through the numerical solution of the dynamical equations. (auth)

  17. Getting beyond hand-waving about microsites with numerical representations of trace gas production and consumption

    Science.gov (United States)

    Sihi, D.; Davidson, E. A.; Savage, K. E.; Liang, D.

    2017-12-01

    Production and consumption of nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) are affected by complex interactions of temperature, moisture, and substrate supply, that is further complicated by spatial heterogeneity of the soil matrix. This microsite heterogeneity is often invoked conceptually to explain unusual observations like consumption of atmospheric N2O (reduction) in upland soils that co-occur with CH4 uptake (oxidation). To advance numerical simulation of these belowground processes, we expanded the Dual Arrhenius and Michaelis-Menten (DAMM) model, to apply it consistently for all three greenhouse gases (GHGs) with respect to the biophysical processes of production, consumption, and diffusion within the soil, including the contrasting effects of oxygen (O2) as substrate or inhibitor for each process. Chamber-based measurements of all three GHGs at the Howland Forest (ME, USA) were used to parameterize the model. The area under a soil chamber is partitioned according to a bivariate lognormal probability distribution function of soil carbon (C) and moisture across a range of microsites, that leads to a distribution of heterotrophic respiration and O2 consumption among microsites. Linking microsite consumption of O2 with a diffusion model generates a broad range of microsite concentrations of O2 that determines the distribution of microsites that produce or consume CH4 and N2O, such that a range of microsite concentrations occur both above and below ambient values for both GHGs. At lower mean soil moisture, some microsites of methanogenesis still occur, but most become sites of methanotrophy. Likewise, concentrations of below ambient N2O (hotspots of N2O reduction) occur in microsites with high C and high moisture (further accentuated at high temperature). Net consumption and production of CH4 and N2O is simulated within a chamber based on the sum of the distribution of soil microsites. Results demonstrate that it is numerically feasible for

  18. The validity and reliability study of Hand Hygiene Belief Scale and Hand Hygiene Practices Inventory

    Directory of Open Access Journals (Sweden)

    Mevlude Karadag

    2016-06-01

    Conclusion: The adaptation of translated and ldquo;Hand Hygiene Belief Scale and Hand Hygiene Practices Inventory and rdquo; in Turkey is found to be reliable and valid to evaluate hand hygiene belief and practices. [Cukurova Med J 2016; 41(2.000: 271-284

  19. Comparative study of presurgical hand hygiene with hydroalcoholic solution versus traditional presurgical hand hygiene.

    Science.gov (United States)

    López Martín, M Beatriz; Erice Calvo-Sotelo, Alejo

    To compare presurgical hand hygiene with hydroalcoholic solution following the WHO protocol with traditional presurgical hand hygiene. Cultures of the hands of surgeons and surgical nurses were performed before and after presurgical hand hygiene and after removing gloves at the end of surgery. Cultures were done in 2different days: the first day after traditional presurgical hand hygiene, and the second day after presurgical hand hygiene with hydroalcoholic solution following the WHO protocol. The duration of the traditional hand hygiene was measured and compared with the duration (3min) of the WHO protocol. The cost of the products used in the traditional technique was compared with the cost of the hydroalcoholic solution used. The variability of the traditional technique was determined by observation. Following presurgical hand hygiene with hydroalcoholic solution, colony-forming units (CFU) were detected in 5 (7.3%) subjects, whereas after traditional presurgical hand hygiene CFU were detected in 14 subjects (20.5%) (p < 0.05). After glove removal, the numbers of CFU were similar. The time employed in hand hygiene with hydroalcoholic solution (3min) was inferior to the time employed in the traditional technique (p < 0.05), its cost was less than half, and there was no variability. Compared with other techniques, presurgical hand hygiene with hydroalcoholic solution significantly decreases CFU, has similar latency time, a lower cost, and saves time. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  20. Ground Robotic Hand Applications for the Space Program study (GRASP)

    Science.gov (United States)

    Grissom, William A.; Rafla, Nader I. (Editor)

    1992-01-01

    This document reports on a NASA-STDP effort to address research interests of the NASA Kennedy Space Center (KSC) through a study entitled, Ground Robotic-Hand Applications for the Space Program (GRASP). The primary objective of the GRASP study was to identify beneficial applications of specialized end-effectors and robotic hand devices for automating any ground operations which are performed at the Kennedy Space Center. Thus, operations for expendable vehicles, the Space Shuttle and its components, and all payloads were included in the study. Typical benefits of automating operations, or augmenting human operators performing physical tasks, include: reduced costs; enhanced safety and reliability; and reduced processing turnaround time.

  1. Case-Cohort Studies: Design and Applicability to Hand Surgery.

    Science.gov (United States)

    Vojvodic, Miliana; Shafarenko, Mark; McCabe, Steven J

    2018-04-24

    Observational studies are common research strategies in hand surgery. The case-cohort design offers an efficient and resource-friendly method for risk assessment and outcomes analysis. Case-cohorts remain underrepresented in upper extremity research despite several practical and economic advantages over case-control studies. This report outlines the purpose, utility, and structure of the case-cohort design and offers a sample research question to demonstrate its value to risk estimation for adverse surgical outcomes. The application of well-designed case-cohort studies is advocated in an effort to improve the quality and quantity of observational research evidence in hand and upper extremity surgery. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  2. Numerical study of fractional nonlinear Schrodinger equations

    KAUST Repository

    Klein, Christian

    2014-10-08

    Using a Fourier spectral method, we provide a detailed numerical investigation of dispersive Schrödinger-type equations involving a fractional Laplacian in an one-dimensional case. By an appropriate choice of the dispersive exponent, both mass and energy sub- and supercritical regimes can be identified. This allows us to study the possibility of finite time blow-up versus global existence, the nature of the blow-up, the stability and instability of nonlinear ground states and the long-time dynamics of solutions. The latter is also studied in a semiclassical setting. Moreover, we numerically construct ground state solutions of the fractional nonlinear Schrödinger equation.

  3. Hand Robotic Therapy in Children with Hemiparesis: A Pilot Study.

    Science.gov (United States)

    Bishop, Lauri; Gordon, Andrew M; Kim, Heakyung

    2017-01-01

    The aim of this study was to understand the impact of training with a hand robotic device on hand paresis and function in a population of children with hemiparesis. Twelve children with hemiparesis (mean age, 9 [SD, 3.64] years) completed participation in this prospective, experimental, pilot study. Participants underwent clinical assessments at baseline and again 6 weeks later with instructions to not initiate new therapies. After these assessments, participants received 6 weeks of training with a hand robotic device, consisting of 1-hour sessions, 3 times weekly. Assessments were repeated on completion of training. Results showed significant improvements after training on the Assisting Hand Assessment (mean difference, 2.0 Assisting Hand Assessment units; P = 0.011) and on the upper-extremity component of the Fugl-Meyer scale (raw score mean difference, 4.334; P = 0.001). No significant improvements between pretest and posttest were noted on the Jebsen-Taylor Test of Hand Function, the Quality of Upper Extremity Skills Test, or the Pediatric Evaluation of Disability Inventory after intervention. Total active mobility of digits and grip strength also failed to demonstrate significant changes after training. Participants tolerated training with the hand robotic device, and significant improvements in bimanual hand use, as well as impairment-based scales, were noted. Improvements were carried over into bimanual skills during play. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Understand key components of neuroplasticity; (2) Discuss the benefits of robotic therapy in the recovery of hand function in pediatric patients with hemiplegia; and (3) Appropriately incorporate robotic therapy into the treatment plan of pediatric patients with hemiplegia. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the

  4. Analytic and numerical studies of Scyllac equilibrium

    International Nuclear Information System (INIS)

    Barnes, D.C.; Brackbill, J.U.; Dagazian, R.Y.; Freidberg, J.P.; Schneider, W.; Betancourt, O.; Garabedian, P.

    1976-01-01

    The results of both numerical and analytic studies of the Scyllac equilibria are presented. Analytic expansions are used to derive equilibrium equations appropriate to noncircular cross sections, and compute the stellarator fields which produce toroidal force balance. Numerical algorithms are used to solve both the equilibrium equations and the full system of dynamical equations in three dimensions. Numerical equilibria are found for both l = 1,0 and l= 1,2 systems. It is found that the stellarator fields which produce equilibria in the l = 1.0 system are larger for diffuse than for sharp boundary plasma profiles, and that the stability of the equilibria depends strongly on the harmonic content of the stellarator fields

  5. Numerical Study of Planar GPR Antenna Measurements

    DEFF Research Database (Denmark)

    Meincke, Peter; Hansen, Thorkild

    2004-01-01

    The formulation of planar near-field measurements of GPR antennas determines the plane-wave spectra of the GPR antenna in terms of measurements obtained with a buried probe as the GPR antenna moves over a scan plane on the ground. A numerical study investigates how the formulation is affected by (1...

  6. Custom-made silicone hand prosthesis: A case study.

    Science.gov (United States)

    Nayak, S; Lenka, P K; Equebal, A; Biswas, A

    2016-09-01

    Up to now, a cosmetic glove was the most common method for managing transmetacarpal (TMC) and carpometacarpal (CMC) amputations, but it is devoid of markings and body color. At this amputation level, it is very difficult to fit a functional prosthesis because of the short available length, unsightly shape, grafted skin, contracture and lack of functional prosthetic options. A 30-year-old male came to our clinic with amputation at the 1st to 4th carpometacarpal level and a 5th metacarpal that was projected laterally and fused with the carpal bone. The stump had grafted skin, redness, and an unhealed suture line. He complained of pain projected over the metacarpal and suture area. The clinical team members decided to fabricate a custom-made silicone hand prosthesis to accommodate the stump, protect the grafted skin, improve the hand's appearance and provide some passive function. The custom silicone hand prosthesis was fabricated with modified flexible wires to provide passive interphalangeal movement. Basic training, care and maintenance instructions for the prosthesis were given to the patient. The silicone hand prosthesis was able to restore the appearance of the lost digits and provide some passive function. His pain (VAS score) was reduced. Improvement in activities of daily living was found in the DASH questionnaire and Jebsen-Taylor Hand Function test. A silicone glove is a good option for more distal amputations, as it can accommodate any deformity, protect the skin, enhance the appearance and provide functional assistance. This case study provides a simple method to get passively movable fingers after proximal hand amputation. Copyright © 2016. Published by Elsevier Masson SAS.

  7. Numerical study of suspensions of deformable particles.

    Science.gov (United States)

    Brandt, Luca; Rosti, Marco Edoardo

    2017-11-01

    We consider a model non-Newtonian fluid consisting of a suspension of deformable particles in a Newtonian solvent. Einstein showed in his pioneering work that the relative increase in effective viscosity is a linear function of the particle volume fraction for dilute suspensions of rigid particles. Inertia has been shown to introduce deviations from the behaviour predicted by the different empirical fits, an effect that can be related to an increase of the effective volume fraction. We here focus on the effect of elasticity, i.e. visco-elastic deformable particles. To tackle the problem at hand, we perform three-dimensional Direct Numerical Simulation of a plane Couette flow with a suspension of neutrally buoyant deformable viscous hyper-elastic particles. We show that elasticity produces a shear-thinning effect in elastic suspensions (in comparison to rigid ones) and that it can be understood in terms of a reduction of the effective volume fraction of the suspension. The deformation modifies the particle motion reducing the level of mutual interaction. Normal stress differences will also be considered. European Research Council, Grant No. ERC-2013-CoG- 616186, TRITOS; SNIC (the Swedish National Infrastructure for Computing).

  8. Gasoline on hands: preliminary study on collection and persistence.

    Science.gov (United States)

    Darrer, Melinda; Jacquemet-Papilloud, Joëlle; Delémont, Olivier

    2008-03-05

    The identification of an arsonist remains one of the most difficult challenges a fire investigation has to face. Seeking and detection of traces of gasoline could provide a valuable information to link a suspect with an arson scene where gasoline was used to set-up the fire. In this perspective, a first study was undertaken to evaluate a simple, fast and efficient method for collecting gasoline from hands, and to assess its persistence over time. Four collection means were tested: PVC, PE and Latex gloves, as well as humidified filter paper. A statistical assessment of the results indicates that Latex and PVC gloves worn for about 20 min, as well as paper filter rubbed on hands, allow an efficient collection of gasoline applied to hands. Due to ease of manipulation and to a reduced amount of volatile compounds detected from the matrix, PVC gloves were selected for the second set of experiments. The evaluation of the persistence of gasoline on hands was then carried out using two initial quantities (500 and 1000 microl). Collection was made with PVC gloves after 0, 30 min, 1, 2 and 4h, on different volunteers. The results show a common tendency of massive evaporation of gasoline during the first 30 min: a continued but non-linear decrease was observed along different time intervals. The results of this preliminary study are in agreement with other previous researches conducted on the detection of flammable liquid residues on clothes, shoes and skin.

  9. A comparative study of hand hygiene and alcohol-based hand rub use among Irish nursing and medical students.

    Science.gov (United States)

    Kingston, Liz M; O'Connell, Nuala H; Dunne, Colum P

    2018-04-01

    In Ireland, the setting for this study, the national prevalence rate of health care-associated infection (HCAI) in acute-care facilities is 5.2%. Hand hygiene and in particular hand rubbing using alcohol-based hand rub (ABHR) is highly efficacious in preventing HCAI transmission. Yet, compliance among healthcare professionals is sub-optimal. Less is known about the practices of nursing and medical students and no study comparing practices among these groups in Ireland was found. Hence, the aim of this study was to provide insight into the current hand hygiene and hand rubbing practices of nursing and medical students in Ireland and, by doing so, contribute to the broader understanding of this topic. This observational study employed a cross-sectional, self-reported design. An electronically administered questionnaire was sent to all nursing and medical students from one university. Data were analysed using appropriate software. The response rate was 37% (323/872). Higher compliance with the World Health Organisation 'my five moments for hand hygiene' model was reported among nursing students (NS) than medical students (MS), with scope for improvement in both disciplines identified. Hand hygiene compliance was highest after body fluid exposure (99.5% NS, 91% MS) and lowest after touching a patient's surroundings (61.5% NS, 57.5% MS). Attitudes towards hand rubbing were largely positive in both disciplines. 16% of NS were not aware of the clinical contraindications to ABHR use, compared to 45% of MS. 9% of NS did not know when to use soap and water and when to use ABHR, compared to 36% of MS. In contrast, more medical students (46%) than nursing students (22%) were routinely using alcohol-based hand rub for decontamination of hands as recommended. Results suggest scope to review current hand hygiene curricula focusing on the knowledge gaps, the practice deficits and the barriers to ABHR usage identified. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Fragrance allergy in patients with hand eczema - a clinical study.

    Science.gov (United States)

    Heydorn, Siri; Johansen, Jeanne Duus; Andersen, Klaus E; Bruze, Magnus; Svedman, Cecilia; White, Ian R; Basketter, David A; Menné, Torkil

    2003-06-01

    Fragrance allergy and hand eczema are both common among dermatological patients. Fragrance mix (FM) and its constituents have a recognized relevance to exposure to fine fragrances and cosmetic products. Based on extensive chemical analysis and database search, a new selection of fragrances was established, including 14 known fragrance allergens present in products to which hand exposure would occur. A non-irritating patch-test concentration for some fragrances was established in 212 consecutive patients. 658 consecutive patients presenting with hand eczema were patch tested with the European standard series and the developed selection of fragrances. 67 (10.2%) of the 658 patients had a positive reaction to 1 or more of our selection of fragrance chemicals present in the new selection. The most common reactions to fragrances not included in the FM were to citral, Lyral (hydroxyisohexyl-3-cyclohexene carboxaldehyde) and oxidized l-limonene. A concomitant reaction to the FM identified potential fragrance allergy in less than (1/2) of these patients. Exposure assessment and a statistically significant association between a positive patch test to our selected fragrances and patients' history support the relevance of this selection of fragrances. Those with a positive reaction to our selected fragrances were significantly more likely to have 1 or more positive patch tests in the standard series. This observation is the basis for the hypothesis concerning cross-reactivity and the effect of simultaneous exposure. The study found that fragrance allergy could be a common problem in patients with eczema on the hands.

  11. Numerical Study of Electric Field Enhanced Combustion

    KAUST Repository

    Han, Jie

    2016-12-26

    Electric fields can be used to change and control flame properties, for example changing flame speed, enhancing flame stability, or reducing pollutant emission. The ions generated in flames are believed to play the primary role. Although experiments have been carried out to study electric field enhanced combustion, they are not sufficient to explain how the ions in a flame are affected by an electric field. It is therefore necessary to investigate the problem through numerical simulations. In the present work, the electric structure of stabilized CH4/air premixed flames at atmospheric pressure within a direct current field is studied using numerical simulations. This study consists of three parts. First, the transport equations are derived from the Boltzmann kinetic equation for each individual species. Second, a general method for computing the diffusivity and mobility of ions in a gas mixture is introduced. Third, the mechanisms for neutral and charged species are improved to give better predictions of the concentrations of charged species, based on experimental data. Following from this, comprehensive numerical results are presented, including the concentrations and fluxes of charged species, the distributions of the electric field and electric potential, and the electric current-voltage relation. Two new concepts introduced with the numerical results are the plasma sheath and dead zone in the premixed flame. A reactive plasma sheath and a Boltzmann relation sheath are discovered in the region near the electrodes. The plasma sheath penetrates into the flame gas when a voltage is applied, and penetrating further if the voltage is higher. The zone outside the region of sheath penetration is defined as the dead zone. With the two concepts, analytical solutions for the electric field, electric potential and current-voltage curve are derived. The solutions directly describe the electric structure of a premixed flame subject to a DC field. These analytical solutions

  12. Feasibility study of a hand guided robotic drill for cochleostomy.

    Science.gov (United States)

    Brett, Peter; Du, Xinli; Zoka-Assadi, Masoud; Coulson, Chris; Reid, Andrew; Proops, David

    2014-01-01

    The concept of a hand guided robotic drill has been inspired by an automated, arm supported robotic drill recently applied in clinical practice to produce cochleostomies without penetrating the endosteum ready for inserting cochlear electrodes. The smart tactile sensing scheme within the drill enables precise control of the state of interaction between tissues and tools in real-time. This paper reports development studies of the hand guided robotic drill where the same consistent outcomes, augmentation of surgeon control and skill, and similar reduction of induced disturbances on the hearing organ are achieved. The device operates with differing presentation of tissues resulting from variation in anatomy and demonstrates the ability to control or avoid penetration of tissue layers as required and to respond to intended rather than involuntary motion of the surgeon operator. The advantage of hand guided over an arm supported system is that it offers flexibility in adjusting the drilling trajectory. This can be important to initiate cutting on a hard convex tissue surface without slipping and then to proceed on the desired trajectory after cutting has commenced. The results for trials on phantoms show that drill unit compliance is an important factor in the design.

  13. Feasibility Study of a Hand Guided Robotic Drill for Cochleostomy

    Directory of Open Access Journals (Sweden)

    Peter Brett

    2014-01-01

    Full Text Available The concept of a hand guided robotic drill has been inspired by an automated, arm supported robotic drill recently applied in clinical practice to produce cochleostomies without penetrating the endosteum ready for inserting cochlear electrodes. The smart tactile sensing scheme within the drill enables precise control of the state of interaction between tissues and tools in real-time. This paper reports development studies of the hand guided robotic drill where the same consistent outcomes, augmentation of surgeon control and skill, and similar reduction of induced disturbances on the hearing organ are achieved. The device operates with differing presentation of tissues resulting from variation in anatomy and demonstrates the ability to control or avoid penetration of tissue layers as required and to respond to intended rather than involuntary motion of the surgeon operator. The advantage of hand guided over an arm supported system is that it offers flexibility in adjusting the drilling trajectory. This can be important to initiate cutting on a hard convex tissue surface without slipping and then to proceed on the desired trajectory after cutting has commenced. The results for trials on phantoms show that drill unit compliance is an important factor in the design.

  14. Numerical study of jets secondary instabilities

    International Nuclear Information System (INIS)

    Brancher, Pierre

    1996-01-01

    The work presented in this dissertation is a contribution to the study of the transition to turbulence in open shear flows. Results from direct numerical simulations are interpreted within the framework of hydrodynamic stability theory. The first chapter is an introduction to the primary and secondary instabilities observed in jets and mixing layers. The numerical method used in the present study is detailed in the second chapter. The dynamics of homogeneous circular jets subjected to stream wise and azimuthal perturbations are investigated in the third chapter. A complete scenario describing the evolution of the jet is proposed with emphasis on the dynamics of vorticity within the flow. In the fourth chapter a parametric study reveals a three-dimensional secondary instability mainly controlled in the linear regime by the Strouhal number of the primary instability. In the nonlinear regime the dynamics of the azimuthal harmonies are described by means of model equations and are linked to the formation of stream wise vortices in the braid. The fifth chapter is dedicated to the convective or absolute nature of the secondary instabilities in plane shear layers. It is shown that there are flow configurations for which the two-dimensional secondary instability (pairing) is absolute even though the primary instability (Kelvin-Helmholtz) is convective. Some preliminary results concerning the three-dimensional secondary instabilities arc presented at the end of this chapter. The last chapter summarizes the main results and examines possible extensions of this work. (author) [fr

  15. Numerical study of nonspherical black hole accretion

    International Nuclear Information System (INIS)

    Hawley, J.F.

    1984-01-01

    This thesis describes in detail a two-dimensional, axisymmetric computer code for calculating fully relativistic ideal gas hydrodynamics around a Kerr black hole. The aim is to study fully dynamic inviscid fluid accretion onto black holes, as well as to study the evolution and development of nonlinear instabilities in pressure supported accretion disks. In order to fully calibrate and document the code, certain analytic solutions for shock tubes and special accretion flows are derived; these solutions form the basis for code testing. The numerical techniques used are developed and discussed. A variety of alternate differencing schemes are compared on an analytic test bed. Some discussion is devoted to general issues in finite differencing. The working code is calibrated using analytically solvable accretion problems, including the radial accretion of dust and of fluid with pressure (Bondi accretion). Two dimensional test problems include the spiraling infall of low angular momentum fluid, the formation of a pressure supported torus, and the stable evolution of a torus. A series of numerical models are discussed and illustrated with selected plots

  16. Cortical Asymmetries during Hand Laterality Task Vary with Hand Laterality: A fMRI Study in 295 Participants

    Science.gov (United States)

    Mellet, Emmanuel; Mazoyer, Bernard; Leroux, Gaelle; Joliot, Marc; Tzourio-Mazoyer, Nathalie

    2016-01-01

    The aim of this study was to characterize, using fMRI, the functional asymmetries of hand laterality task (HLT) in a sample of 295 participants balanced for handedness. During HLT, participants have to decide whether the displayed picture of a hand represent a right or a left hand. Pictures of hands’ back view were presented for 150 ms in the right or left hemifield. At the whole hemisphere level, we evidenced that the laterality of the hand and of the hemifield in which the picture was displayed combined their effects on the hemispheric asymmetry in an additive way. We then identified a set of 17 functional homotopic regions of interest (hROIs) including premotor, motor, somatosensory and parietal regions, whose activity and asymmetry varied with the laterality of the presented hands. When the laterality of a right hand had to be evaluated, these areas showed stronger leftward asymmetry, the hROI located in the primary motor area showing a significant larger effect than all other hROIs. In addition a subset of six parietal regions involved in visuo-motor integration together with two postcentral areas showed a variation in asymmetry with hemifield of presentation. Finally, while handedness had no effect at the hemispheric level, two regions located in the parietal operculum and intraparietal sulcus exhibited larger leftward asymmetry with right handedness independently of the hand of presentation. The present results extend those of previous works in showing a shift of asymmetries during HLT according to the hand presented in sensorimotor areas including primary motor cortex. This shift was not affected by manual preference. They also demonstrate that the coordination of visual information and handedness identification of hands relied on the coexistence of contralateral motor and visual representations in the superior parietal lobe and the postcentral gyrus. PMID:27999536

  17. The fragrance hand immersion study - an experimental model simulating real-life exposure for allergic contact dermatitis on the hands

    DEFF Research Database (Denmark)

    Heydorn, S; Menné, T; Andersen, K E

    2003-01-01

    previously diagnosed with hand eczema to explore whether immersion of fingers in a solution with or without the patch-test-positive fragrance allergen would cause or exacerbate hand eczema on the exposed finger. The study was double blinded and randomized. All participants had a positive patch test to either...... hydroxycitronellal or Lyral (hydroxyisohexyl 3-cyclohexene carboxaldehyde). Each participant immersed a finger from each hand, once a day, in a solution containing the fragrance allergen or placebo. During the first 2 weeks, the concentration of fragrance allergen in the solution was low (approximately 10 p...... meter. 3 of 15 hand eczema patients developed eczema on the finger immersed in the fragrance-containing solution, 3 of 15 on the placebo finger and 3 of 15 on both fingers. Using this experimental exposure model simulating real-life exposure, we found no association between immersion of a finger...

  18. Study of hand signs in Judeo-Christian art.

    Science.gov (United States)

    Ram, Ashwin N; Chung, Kevin C

    2008-09-01

    Hand gestures play a crucial role in religious art. An examination of Judeo-Christian art finds an ecclesiastical language that is concealed in metaphors and expressed by unique hand gestures. Many of these hand signs convey messages that are not familiar to most people admiring these paintings. Investigating the history and classifying some of the predominant hand signs found in Judeo-Christian art might serve to stimulate discussion concerning the many nuances of symbolic art. This presentation examines the meaning behind 8 common hand signs in Judeo-Christian art.

  19. Hand sanitizer-dispensing door handles increase hand hygiene compliance: a pilot study.

    Science.gov (United States)

    Babiarz, Lukasz S; Savoie, Brent; McGuire, Mark; McConnell, Lauren; Nagy, Paul

    2014-04-01

    Improving rates of hand hygiene compliance (HHC) has been shown to reduce nosocomial disease. We compared the HHC for a traditional wall-mounted unit and a novel sanitizer-dispensing door handle device in a hospital inpatient ultrasound area. HHC increased 24.5%-77.1% (P sanitizer-dispensing door handle, whereas it remained unchanged for the other rooms. Technical improvements like a sanitizer-dispensing door handle can improve hospital HHC. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  20. High energy gravitational scattering: a numerical study

    CERN Document Server

    Marchesini, Giuseppe

    2008-01-01

    The S-matrix in gravitational high energy scattering is computed from the region of large impact parameters b down to the regime where classical gravitational collapse is expected to occur. By solving the equation of an effective action introduced by Amati, Ciafaloni and Veneziano we find that the perturbative expansion around the leading eikonal result diverges at a critical value signalling the onset of a new regime. We then discuss the main features of our explicitly unitary S-matrix down to the Schwarzschild's radius R=2G s^(1/2), where it diverges at a critical value b ~ 2.22 R of the impact parameter. The nature of the singularity is studied with particular attention to the scaling behaviour of various observables at the transition. The numerical approach is validated by reproducing the known exact solution in the axially symmetric case to high accuracy.

  1. Numerical Study of Corrosion Crack Opening

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Frandsen, Henrik Lund; Svensson, Staffan

    2008-01-01

    is proportional. More recently, the constant of proportionality, the so-called crack-corrosion index, has been studied further with respect to its dependence on the diameter of the reinforcement and the concrete cover. In the present paper the above-mentioned work is presented and extended with more realistic 3D......-models of the cracked concrete beam. The crack-corrosion index is evaluated for a variation of different parameters, i.e. bar diameter, concrete cover, crack length and type of corrosion product. This paper is an extended version of a paper by Thoft-Christensen et al. (2005) presented at the IFIP WG 7.5 Conference...... for the corrosion crack opening. Experiments and theoretical analysis by a numerical method, FEM, support that the relation between the reduction of the reinforcement bar diameter due to corrosion and the corresponding increase in crack width for a given time interval, measured on the surface of a concrete specimen...

  2. Hand eczema in hairdressers: a Danish register-based study of the prevalence of hand eczema and its career consequences.

    Science.gov (United States)

    Lysdal, Susan Hovmand; Søsted, Heidi; Andersen, Klaus Ejner; Johansen, Jeanne Duus

    2011-09-01

    Occupational hand eczema is common in hairdressers, owing to wet work and hairdressing chemicals. To estimate the prevalence of hand eczema and its career consequences among hairdressers in Denmark. A register-based study was conducted, comprising all graduates from hairdressing vocational schools from 1985 to 2007 (n = 7840). The participants received a self-administered postal questionnaire including questions on hand eczema, atopic dermatitis, and career change. A response rate of 67.9% (n = 5324) was obtained. Of the respondents, 44.3% no longer worked as hairdressers and had worked for an average of 8.4 years in the profession before leaving it. Hand eczema was more common among ex-hairdressers (48.4%) than among current hairdressers (37.6%) (p reason for career change. In this group, logistic regression analysis showed that chronic hand eczema contributed the most to the decision to change career (odds ratio 50.12; 95% confidence interval 18.3-137). Hairdressers work an average of 8.4 years in the profession before leaving it, and hand eczema contributes significantly to this career change. © 2011 John Wiley & Sons A/S.

  3. [Study on an Exoskeleton Hand Function Training Device].

    Science.gov (United States)

    Hu, Xin; Zhang, Ying; Li, Jicai; Yi, Jinhua; Yu, Hongliu; He, Rongrong

    2016-02-01

    Based on the structure and motion bionic principle of the normal adult fingers, biological characteristics of human hands were analyzed, and a wearable exoskeleton hand function training device for the rehabilitation of stroke patients or patients with hand trauma was designed. This device includes the exoskeleton mechanical structure and the electromyography (EMG) control system. With adjustable mechanism, the device was capable to fit different finger lengths, and by capturing the EMG of the users' contralateral limb, the motion state of the exoskeleton hand was controlled. Then driven by the device, the user's fingers conducting adduction/abduction rehabilitation training was carried out. Finally, the mechanical properties and training effect of the exoskeleton hand were verified through mechanism simulation and the experiments on the experimental prototype of the wearable exoskeleton hand function training device.

  4. Getting Their Hands Dirty: Qualitative Study on Hands-on Learning for Architectural Students in Design-build Course

    Directory of Open Access Journals (Sweden)

    Zunaibi B. Abdullah

    2011-06-01

    Full Text Available This qualitative study provides an in-depth perspective of hands-on learning through the observation and analysis of architectural students' views in a design-build program at the University of Nebraska-Lincoln during the fall semester of 2008. Qualitative data was gathered from 14 participants involved in the construction of a low energy double-storey house in the city of Lincoln, Nebraska. The study inventoried the requisite characteristics of a design-build course. Participants' views and activities were studied to ascribe the qualitative benefits of hands-on learning. In addition, students' motivation towards hands-on activities were evaluated in reference to student confidence and independence levels towards their future career as architects, designers or other design-build professionals. The findings showed the design-build course could offer a specific knowledge that link between theoretical subjects and the practical expect of building contractions.

  5. The fragrance hand immersion study - an experimental model simulating real-life exposure for allergic contact dermatitis on the hands.

    Science.gov (United States)

    Heydorn, S; Menné, T; Andersen, K E; Bruze, M; Svedman, C; Basketter, D; Johansen, J D

    2003-06-01

    Recently, we showed that 10 x 2% of consecutively patch-tested hand eczema patients had a positive patch test to a selection of fragrances containing fragrances relevant to hand exposure. In this study, we used repeated skin exposure to a patch test-positive fragrance allergen in patients previously diagnosed with hand eczema to explore whether immersion of fingers in a solution with or without the patch-test-positive fragrance allergen would cause or exacerbate hand eczema on the exposed finger. The study was double blinded and randomized. All participants had a positive patch test to either hydroxycitronellal or Lyral (hydroxyisohexyl 3-cyclohexene carboxaldehyde). Each participant immersed a finger from each hand, once a day, in a solution containing the fragrance allergen or placebo. During the first 2 weeks, the concentration of fragrance allergen in the solution was low (approximately 10 p.p.m.), whilst during the following 2 weeks, the concentration was relatively high (approximately 250 p.p.m.), imitating real-life exposure to a household product like dishwashing liquid diluted in water and the undiluted product, respectively. Evaluation was made using a clinical scale and laser Doppler flow meter. 3 of 15 hand eczema patients developed eczema on the finger immersed in the fragrance-containing solution, 3 of 15 on the placebo finger and 3 of 15 on both fingers. Using this experimental exposure model simulating real-life exposure, we found no association between immersion of a finger in a solution containing fragrance and development of clinically visible eczema on the finger in 15 participants previously diagnosed with hand eczema and with a positive patch test to the fragrance in question.

  6. Numerical study of fractional nonlinear Schrodinger equations

    KAUST Repository

    Klein, Christian; Sparber, Christof; Markowich, Peter A.

    2014-01-01

    Using a Fourier spectral method, we provide a detailed numerical investigation of dispersive Schrödinger-type equations involving a fractional Laplacian in an one-dimensional case. By an appropriate choice of the dispersive exponent, both mass

  7. ORIGINAL ARTICLES A radiological study of the rheumatoid hand in ...

    African Journals Online (AJOL)

    Nicky

    There are only a few publications on rheumatoid involvement in black South Africans.1-3 These publications do not address wrist and hand involvement specifically in black patients. However, when treating black patients one gets the impression that the wrist is more severely affected than the rest of the hand. In his thesis ...

  8. Mental rotation of anthropoid hands: a chronometric study

    Directory of Open Access Journals (Sweden)

    L.G. Gawryszewski

    2007-03-01

    Full Text Available It has been shown that mental rotation of objects and human body parts is processed differently in the human brain. But what about body parts belonging to other primates? Does our brain process this information like any other object or does it instead maximize the structural similarities with our homologous body parts? We tried to answer this question by measuring the manual reaction time (MRT of human participants discriminating the handedness of drawings representing the hands of four anthropoid primates (orangutan, chimpanzee, gorilla, and human. Twenty-four right-handed volunteers (13 males and 11 females were instructed to judge the handedness of a hand drawing in palm view by pressing a left/right key. The orientation of hand drawings varied from 0º (fingers upwards to 90º lateral (fingers pointing away from the midline, 180º (fingers downwards and 90º medial (finger towards the midline. The results showed an effect of rotation angle (F(3, 69 = 19.57, P < 0.001, but not of hand identity, on MRTs. Moreover, for all hand drawings, a medial rotation elicited shorter MRTs than a lateral rotation (960 and 1169 ms, respectively, P < 0.05. This result has been previously observed for drawings of the human hand and related to biomechanical constraints of movement performance. Our findings indicate that anthropoid hands are essentially equivalent stimuli for handedness recognition. Since the task involves mentally simulating the posture and rotation of the hands, we wondered if "mirror neurons" could be involved in establishing the motor equivalence between the stimuli and the participants' own hands.

  9. Fragrance allergy in patients with hand eczema - a clinical study

    DEFF Research Database (Denmark)

    Heydorn, Siri; Johansen, Jeanne Duus; Andersen, Klaus E

    2003-01-01

    Fragrance allergy and hand eczema are both common among dermatological patients. Fragrance mix (FM) and its constituents have a recognized relevance to exposure to fine fragrances and cosmetic products. Based on extensive chemical analysis and database search, a new selection of fragrances...... was established, including 14 known fragrance allergens present in products to which hand exposure would occur. A non-irritating patch-test concentration for some fragrances was established in 212 consecutive patients. 658 consecutive patients presenting with hand eczema were patch tested with the European...

  10. Quantification of manganese in human hand bones: a feasibility study

    International Nuclear Information System (INIS)

    Aslam; Pejovic-Milic, A; Chettle, D R; McNeill, F E

    2008-01-01

    Manganese is both an essential element to human health and also toxic when humans are exposed to excessive levels, particularly by means of inhalation. Biological monitoring of manganese exposure is problematic. It is subject to homeostasis; levels in blood (or serum/plasma) reflect only the most recent exposure and rapidly return to within normal ranges, even when there has been a temporary excursion in response to exposure. In this context, we have been developing a non-invasive technique for measurement of manganese stored in bone, using in vivo neutron activation analysis. Following preliminary feasibility studies, the technique has been enhanced by two significant infrastructure advances. A specially designed irradiation facility serves to maximize the activation of manganese with respect to the dose of ionizing radiation. Secondly, an array of eight NaI(Tl) crystals provides a detection system with very close to 4π geometry. This feasibility study, using neutron activation analysis to measure manganese in the bones of the hand, takes two features into account. Firstly, there is considerable magnesium present in the bone and this produces a spectral interference with the manganese. The 26 Mg(n,γ) 27 Mg reaction produces γ-rays of 0.843 MeV from the decay of 27 Mg, which interfere with the 0.847 MeV γ-rays from the decay of 56 Mn, produced by the 55 Mn(n,γ) 56 Mn reaction. Secondly, this work provides estimates of the levels of manganese to be expected in referent subjects. A revised estimate has been made from the most recent literature to explore the potential of the technique as a suitable means of screening patients and people exposed to excessive amounts of Mn who could develop many-fold increased levels of Mn in bones as demonstrated through various animal studies. This report presents the enhancements to the neutron activation system, by which manganese can be measured, which resulted in a detection limit in the hand of human subjects of 1.6

  11. Quantification of manganese in human hand bones: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Aslam; Pejovic-Milic, A; Chettle, D R; McNeill, F E [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, L8S 4K1 (Canada)], E-mail: aslamib@mcmaster.ca

    2008-08-07

    Manganese is both an essential element to human health and also toxic when humans are exposed to excessive levels, particularly by means of inhalation. Biological monitoring of manganese exposure is problematic. It is subject to homeostasis; levels in blood (or serum/plasma) reflect only the most recent exposure and rapidly return to within normal ranges, even when there has been a temporary excursion in response to exposure. In this context, we have been developing a non-invasive technique for measurement of manganese stored in bone, using in vivo neutron activation analysis. Following preliminary feasibility studies, the technique has been enhanced by two significant infrastructure advances. A specially designed irradiation facility serves to maximize the activation of manganese with respect to the dose of ionizing radiation. Secondly, an array of eight NaI(Tl) crystals provides a detection system with very close to 4{pi} geometry. This feasibility study, using neutron activation analysis to measure manganese in the bones of the hand, takes two features into account. Firstly, there is considerable magnesium present in the bone and this produces a spectral interference with the manganese. The {sup 26}Mg(n,{gamma}){sup 27}Mg reaction produces {gamma}-rays of 0.843 MeV from the decay of {sup 27}Mg, which interfere with the 0.847 MeV {gamma}-rays from the decay of {sup 56}Mn, produced by the {sup 55}Mn(n,{gamma}){sup 56}Mn reaction. Secondly, this work provides estimates of the levels of manganese to be expected in referent subjects. A revised estimate has been made from the most recent literature to explore the potential of the technique as a suitable means of screening patients and people exposed to excessive amounts of Mn who could develop many-fold increased levels of Mn in bones as demonstrated through various animal studies. This report presents the enhancements to the neutron activation system, by which manganese can be measured, which resulted in a detection

  12. Parametrical Numerical Study on Breakwater SSG Application

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Kofoed, Jens Peter

    The report presents numerical investigations on the performance of the SSG concept for different tide and wave conditions towards different levels of discretization to an optimal solution. Benefit of extra reservoir utilization and reservoir length has also been investigated. The report must be c...

  13. Numerical

    Directory of Open Access Journals (Sweden)

    M. Boumaza

    2015-07-01

    Full Text Available Transient convection heat transfer is of fundamental interest in many industrial and environmental situations, as well as in electronic devices and security of energy systems. Transient fluid flow problems are among the more difficult to analyze and yet are very often encountered in modern day technology. The main objective of this research project is to carry out a theoretical and numerical analysis of transient convective heat transfer in vertical flows, when the thermal field is due to different kinds of variation, in time and space of some boundary conditions, such as wall temperature or wall heat flux. This is achieved by the development of a mathematical model and its resolution by suitable numerical methods, as well as performing various sensitivity analyses. These objectives are achieved through a theoretical investigation of the effects of wall and fluid axial conduction, physical properties and heat capacity of the pipe wall on the transient downward mixed convection in a circular duct experiencing a sudden change in the applied heat flux on the outside surface of a central zone.

  14. Theoretical and numerical study of highly anisotropic turbulent flows

    NARCIS (Netherlands)

    Biferale, L.; Daumont, I.; Lanotte, A.; Toschi, F.

    2004-01-01

    We present a detailed numerical study of anisotropic statistical fluctuations in stationary, homogeneous turbulent flows. We address both problems of intermittency in anisotropic sectors, and the relative importance of isotropic and anisotropic fluctuations at different scales on a direct numerical

  15. Biofouling in forward osmosis systems: An experimental and numerical study

    KAUST Repository

    Bucs, Szilard; Valladares Linares, Rodrigo; Vrouwenvelder, Johannes S.; Picioreanu, Cristian

    2016-01-01

    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute

  16. Brachyphalangism and brachymetapodia of the hand. A radiological study

    Energy Technology Data Exchange (ETDEWEB)

    Pryde, A W; Kitabatake, Takashi

    1960-10-01

    Left hand roentgenograms were studied of Japanese children of Hiroshima divided into three groups; Group I was 1302 male and 1237 female normal, healthy controls; Group II was 219 children exposed to the atomic bomb on August 6, 1945 while still intra-utero; Group III was 174 non-exposed control children who were intra-utero on August 6, 1945. Brachymesophalangism of the left little finger was found in the control children in 14.13 percent of males and 21.26 percent of females when epiphyseal irregularity as well as actual shortening is considered as a criterion. Incidence of brachymesophalangism of the left little finger was not significantly different for children exposed to the atomic bomb while intra-utero. Bone age of children with brachymesophalangism and those exposed to the atomic bomb while intra-utero showed no difference from the normal. Brachytelephalangism of the thumb occurs in 2.1 percent of normal boys and in 2.9 percent of normal girls. A possible relation between brachymesophalangism of the little finger and brachytelephalangism of the thumb occurring in the same child is suggested by an association significant at the 5 percent level. Brachymetapodia occurred in 0.2 percent of normal boys and 0.6 percent in girls and was seen most often in the fifth metacarpal. 21 references, 6 tables.

  17. The Clinical Assessment Study of the Hand (CAS-HA: a prospective study of musculoskeletal hand problems in the general population

    Directory of Open Access Journals (Sweden)

    Marshall Michelle

    2007-08-01

    Full Text Available Abstract Background Pain in the hand affects an estimated 12–21% of the population, and at older ages the hand is one of the most common sites of pain and osteoarthritis. The association between symptomatic hand osteoarthritis and disability in everyday life has not been studied in detail, although there is evidence that older people with hand problems suffer significant pain and disability. Despite the high prevalence of hand problems and the limitations they cause in older adults, little attention has been paid to the hand by health planners and policy makers. We plan to conduct a prospective, population-based, observational cohort study designed in parallel with our previously reported cohort study of knee pain, to describe the course of musculoskeletal hand problems in older adults and investigate the relative merits of different approaches to classification and defining prognosis. Methods/Design All adults aged 50 years and over registered with two general practices in North Staffordshire will be invited to take part in a two-stage postal survey. Respondents to the survey who indicate that they have experienced hand pain or problems within the previous 12 months will be invited to attend a research clinic for a detailed assessment. This will consist of clinical interview, hand assessment, screening test of lower limb function, digital photography, plain x-rays, anthropometric measurement and brief self-complete questionnaire. All consenting clinic attenders will be followed up by (i general practice medical record review, (ii repeat postal questionnaire at 18-months, and (iii repeat postal questionnaire at 3 years. Discussion This paper describes the protocol for the Clinical Assessment Study of the Hand (CAS-HA, a prospective, population-based, observational cohort study of community-dwelling older adults with hand pain and hand problems based in North Staffordshire.

  18. Hand trauma: A prospective observational study reporting diagnostic concordance in emergency hand trauma which supports centralised service improvements.

    Science.gov (United States)

    Miranda, B H; Spilsbury, Z P; Rosala-Hallas, A; Cerovac, S

    2016-10-01

    Hand injuries are common, contributing up to 30% of accident and emergency (A&E) attendances. The aim of this study was to prospectively analyse the pathological demographics of hand injuries in a level 1 trauma centre with a Hand Trauma Unit and direct A&E links, and compare clinical and intra-operative findings. The null hypothesis was that there would be no differences between clinical and intra-operative findings (100% diagnostic concordance). Data were prospectively collected for referrals during 2012. Referral diagnosis, additional pathologies found on clinical assessment and intra-operative findings were documented on a live database accessible from both the Hand Unit and associated operating theatres. Odds ratios were calculated using SAS. Injuries (1526) were identified in 1308 patients included in the study. Diagnostic concordance between Hand Unit clinical examination and intra-operative findings was 92.5% ± 2.85% (mean ± SEM); this was lower for flexor tendon injuries (56.3%) because a greater number of additional pathologies were found intra-operatively (2.25 ± 0.10). This 'trend' was noted across multiple referral pathologies including phalangeal fractures (1.28 ± 0.02; 82.9%), lacerations (1.33 ± 0.04; 79.1%), extensor tendon injuries (1.30 ± 0.05; 87.8%) and dislocations (1.18 ± 0.05; 87.8%). Odds ratio analysis indicated a relationship between primary referral diagnoses that were more or less likely to be associated with additional injuries (p management of hand trauma. Our findings, coupled with the presented relevant literature reports, lead us to advocate that A&E departments should move towards a system wherein links to specialist hand trauma services are in place; we hereby present useful data for hospitals implementing such services. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  19. Combustion Behaviour of Pulverised Wood - Numerical and Experimental Studies. Part 1 Numerical Study

    Energy Technology Data Exchange (ETDEWEB)

    Elfasakhany, A.; Xue-Song Bai [Lund Inst. of Tech. (Sweden). Dept. of Heat and Power Engineering

    2002-12-01

    This report describes a theoretical/numerical investigation of the particle motion and the particle drying, pyrolysis, oxidation of volatile and char in a pulverised biofuel (wood) flame. This work, along with the experimental measurement of a pulverised wood flame in a vertical furnace at TPS, is supported by the Swedish Energy Agency, STEM. The fundamental combustion process of a pulverised wood flame with determined size distribution and anisotropy character is studied. Comprehensive submodels are studied and some models not available in the literature are developed. The submodels are integrated to a CFD code, previously developed at LTH. The numerical code is used to simulate the experimental flame carried out at TPS (as sub-task 2 within the project). The sub-models describe the drying, devolatilization, char formation of wood particles, and the oxidation reaction of char and the gas phase volatile. At the present stage, the attention is focused on the understanding and modelling of non-spherical particle dynamics and the drying, pyrolysis, and oxidation of volatile and char. Validation of the sub-models against the experimental data is presented and discussed in this study. The influence of different factors on the pulverised wood flame in the TPS vertical furnace is investigated. This includes shape of the particles, the effect of volatile release, as well as the orientation of the particles on the motion of the particles. The effect of particle size on the flame structure (distribution of species and temperature along the axis of the furnace) is also studied. The numerical simulation is in close agreement with the TPS experimental data in the concentrations of species O{sub 2}, CO{sub 2} as well as temperature. Some discrepancy between the model simulations and measurements is observed, which suggests that further improvement in our understanding and modeling the pulverised wood flame is needed.

  20. A numerical study of non-isothermal turbulent coaxial jets

    Energy Technology Data Exchange (ETDEWEB)

    Kriaa, Wassim; Abderrazak, Kamel; Mhiri, Hatem [Ecole Nationale d' Ingenieurs de Monastir, Laboratoire de Mecanique des Fluides et Thermique, Monastir (Tunisia); Palec, Georges le; Bournot, Philippe [Institut de Mecanique de Marseille, Marseille (France)

    2008-07-15

    In this work, we propose to study non isothermal air-air coaxial jets with two different approaches: parabolic and elliptic approaches. The standard k-{epsilon} model and the RSM model were applied in this study. The numerical resolution of the equations governing this flow type was carried out for: the parabolic approach, by a ''home-made'' CFD code based on a finite difference method, and the elliptic approach by an industrial code (FLUENT) based on a finite volume method. In forced convection mode (Fr={infinity}), the two turbulence models are valid for the prediction of the mean flow. But for turbulent sizes, k-{epsilon} model gives results closer to those achieved in experiments compared to RSM Model. Concerning the limit of validity of the parabolic and elliptic approaches, we showed that for velocities ratio r lower than 1, the results of the two approaches were satisfactory. On the other hand, for r>1, the difference between the results became increasingly significant. In mixed convection mode (Fr{approx_equal}20), the results obtained by the two turbulence models for the mean axial velocity were very different even in the plume region. For the temperature and the turbulent sizes the two models give satisfactory results which agree well with the correlations suggested by the experimenters for X{>=}20. Thus, the second order model with {sigma}{sub t}=0.85 is more effective for a coaxial jet study in a mixed convection mode. (orig.)

  1. An elicitation study of critical care nurses' salient hand hygiene beliefs.

    Science.gov (United States)

    Piras, Susan E; Lauderdale, Jana; Minnick, Ann

    2017-10-01

    To describe critical care nurses' hand hygiene attitudinal, normative referent, and control beliefs. Hand hygiene is the primary strategy to prevent healthcare-associated infections. Social influence is an underdeveloped hand hygiene strategy. This qualitative descriptive study was conducted with 25 ICU nurses in the southeastern United States. Data were collected using the Nurses' Salient Belief Instrument. Thematic analysis generated four themes: Hand Hygiene is Protective; Nurses look to Nurses; Time-related Concerns; and Convenience is Essential. Nurses look to nurses as hand hygiene referents and believe hand hygiene is a protective behaviour that requires time and functional equipment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Comparative assessment of antimicrobial efficacy of different hand sanitizers: An in vitro study

    OpenAIRE

    Jain, Vardhaman Mulchand; Karibasappa, Gundabaktha Nagappa; Dodamani, Arun Suresh; Prashanth, Vishwakarma K.; Mali, Gaurao Vasant

    2016-01-01

    Background: To evaluate the antimicrobial efficacy of four different hand sanitizers against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis as well as to assess and compare the antimicrobial effectiveness among four different hand sanitizers. Materials and Methods: The present study is an in vitro study to evaluate antimicrobial efficacy of Dettol, Lifebuoy, PureHands, and Sterillium hand sanitizers against clinical i...

  3. Fragrance allergy in patients with hand eczema - a clinical study

    DEFF Research Database (Denmark)

    Heydorn, Siri; Johansen, Jeanne Duus; Andersen, Klaus E

    2003-01-01

    Fragrance allergy and hand eczema are both common among dermatological patients. Fragrance mix (FM) and its constituents have a recognized relevance to exposure to fine fragrances and cosmetic products. Based on extensive chemical analysis and database search, a new selection of fragrances was es...

  4. Numerical studies of impurities in fusion plasmas

    International Nuclear Information System (INIS)

    Hulse, R.A.

    1982-09-01

    The coupled partial differential equations used to describe the behavior of impurity ions in magnetically confined controlled fusion plasmas require numerical solution for cases of practical interest. Computer codes developed for impurity modeling at the Princeton Plasma Physics Laboratory are used as examples of the types of codes employed for this purpose. These codes solve for the impurity ionization state densities and associated radiation rates using atomic physics appropriate for these low-density, high-temperature plasmas. The simpler codes solve local equations in zero spatial dimensions while more complex cases require codes which explicitly include transport of the impurity ions simultaneously with the atomic processes of ionization and recombination. Typical applications are discussed and computational results are presented for selected cases of interest

  5. Numerical study of MHD supersonic flow control

    Science.gov (United States)

    Ryakhovskiy, A. I.; Schmidt, A. A.

    2017-11-01

    Supersonic MHD flow around a blunted body with a constant external magnetic field has been simulated for a number of geometries as well as a range of the flow parameters. Solvers based on Balbas-Tadmor MHD schemes and HLLC-Roe Godunov-type method have been developed within the OpenFOAM framework. The stability of the solution varies depending on the intensity of magnetic interaction The obtained solutions show the potential of MHD flow control and provide insights into for the development of the flow control system. The analysis of the results proves the applicability of numerical schemes, that are being used in the solvers. A number of ways to improve both the mathematical model of the process and the developed solvers are proposed.

  6. Hand Movements and Braille Reading Efficiency: Data from the Alphabetic Braille and Contracted Braille Study

    Science.gov (United States)

    Wright, Tessa; Wormsley, Diane P.; Kamei-Hannan, Cheryl

    2009-01-01

    Using a subset of data from the Alphabetic Braille and Contracted Braille Study, researchers analyzed the patterns and characteristics of hand movements as predictors of reading performance. Statistically significant differences were found between one- and two-handed readers and between patterns of hand movements and reading rates. (Contains 6…

  7. Evaluation of antibacterial activity of hand sanitizers – an in vitro study

    African Journals Online (AJOL)

    Hand hygiene, particularly hand sanitizing, is essential in reducing infectious disease transmission. The recent outbreak of Ebola in Nigeria both increased public awareness of the practice of hand sanitizing and resulted in the introduction of new products to the Nigerian market. This study set out to explore the actual ...

  8. Prevalence and pattern of radiographic hand osteoarthritis and association with pain and disability (the Rotterdam study)

    NARCIS (Netherlands)

    S. Dahaghin; S.M. Bierma-Zeinstra (Sita); A.Z. Ginai (Abida); H.A.P. Pols (Huib); J.M.W. Hazes (Mieke); B.W. Koes (Bart)

    2005-01-01

    textabstractOBJECTIVE: To investigate the prevalence and pattern of radiographic osteoarthritis (ROA) of the hand joints and its association with self reported hand pain and disability. METHODS: Baseline data on a population based study (age >/=55 years) were used (n = 3906). Hand

  9. Numerical studies of gauge field theories

    International Nuclear Information System (INIS)

    Creutz, M.

    1981-06-01

    Monte Carlo simulation of statistical systems is a well established technique of the condensed matter physicist. In the last few years, particle theorists have rediscovered this method and are having a marvelous time applying it to quantized gauge field theories. The main result has been strong numerical evidence that the standard SU(3) non-Abelian gauge theory of the strong interaction is capable of simultaneously confining quarks into the physical hadrons and exhibiting asymptotic freedom, the phenomenon of quark interactions being small at short distances. In four dimensions, confinement is a non-perturbative phenomenon. Essentially all models of confinement tie widely separated quarks together with strings of gauge field flux. This gives rise to a linear potential at long distances. A Monte Carlo program generates a sequence of field configuration by a series of random changes of the fields. The algorithm is so constructed that ultimately the probability density for finding any given configuration is proportional to the Boltzmann weighting. We bring our lattices into thermal equilibrium with a heat bath at a temperature specified by the coupling constant. Thus we do computer experiments with four-dimensional crystals stored in a computer memory. As the entire field configuration is stored, we have access to any correlation function desired. These lectures describe the kinds of experiments being done and the implications of these results for strong interaction physics

  10. Retrospective study of work related traumatic hand injuries

    Directory of Open Access Journals (Sweden)

    Tamara Pereira de Oliveira

    2013-08-01

    Full Text Available The hand is an instrument extensively used in daily life activities- practical and professional; and it is, consequently, often injured, causing impact on productivity and on the country’s economy, also affecting the quality of life of individuals. When the lesion is work-related, it should be reported and referred by the service unit to Worker Health Reference Centre (CEREST. However, systems of records of occupational accidents are still little explored in Brazil. The aim of this work was to conduct a retrospective data survey on hand traumatic injuries of patients treated at CEREST in the municipality of Jundiaí, Sao Paulo state, in order to know the profile of these victims. Data were collected from the records of SINAN card - Severe Accident Research Sheet, in 2009. Of the 416 cases reported at SINAN, 45.2% were accidents involving the hand, which were reported mostly by private hospitals. 70.7% of the accidents reported occurred in the city (Jundiai and 88.3% of them took place within the premises of companies. Men aged between 19 and 39 years old were the most affected. Machine operators presented the highest accident incidence and fracture was the most frequent diagnosis. Temporary disability reached 80.3% of workers. 89.3% worked under formal contracts. Investment in record systems of labor accidents is essential because it would prevent underreporting and improve awareness of employees and public agencies regarding prevention and rehabilitation, thus avoiding inability of workers and damage to businesses and the government.

  11. Numerical study of fluid motion in bioreactor with two mixers

    Energy Technology Data Exchange (ETDEWEB)

    Zheleva, I., E-mail: izheleva@uni-ruse.bg [Department of Heat Technology, Hydraulics and Ecology, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria); Lecheva, A., E-mail: alecheva@uni-ruse.bg [Department of Mathematics, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria)

    2015-10-28

    Numerical study of hydrodynamic laminar behavior of a viscous fluid in bioreactor with multiple mixers is provided in the present paper. The reactor is equipped with two disk impellers. The fluid motion is studied in stream function-vorticity formulation. The calculations are made by a computer program, written in MATLAB. The fluid structure is described and numerical results are graphically presented and commented.

  12. Hand hygiene compliance in transplant and other special patient groups: an observational study.

    Science.gov (United States)

    Graf, Karolin; Ott, Ella; Wolny, Michael; Tramp, Nadine; Vonberg, Ralf-Peter; Haverich, Axel; Chaberny, Iris Freya

    2013-06-01

    This study evaluates hand hygiene behavior of health care workers in a German university hospital stratified for treatment of special patient groups (eg, transplant patients). From 2008 to 2010, comprehensive education and training of all health care workers was implemented to improve hand hygiene compliance. Consumption rates of alcohol-based hand rub and gloves were collected and evaluated. Of the 5,647 opportunities of hand disinfection evaluated, 1,607 occurred during care for transplant patients. To our knowledge, this is the largest survey of hand hygiene compliance in special patient groups on intensive care units in a university hospital in Germany. Health care workers on surgical intensive care units showed lower hand hygiene compliance compared with health care workers on other types of intensive care units. Compliance toward hand hygiene was significantly higher on hemato-oncologic and pediatric wards. In general, hand disinfection was performed significantly more frequently after an intervention than before (P hand hygiene compliance when caring for transplant patients or other patients (odds ratio, 1.16; 95% confidence interval: 0.95-1.42). Nurse's and physician's hand hygiene compliance improved because of education. Hand hygiene compliance is not increased in the care for transplant patients (despite their predisposition for nosocomial infections) compared with other patients. Additional studies will be necessary to further investigate these findings. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  13. Numerical Study on POSRV Leak Detection

    International Nuclear Information System (INIS)

    Ko, Yong Sang; Baik, Se Jin; Cho, Yoon Jae; Yune, Seok Jeong; Kim, Eun Kee

    2015-01-01

    This study shows that the selected temperature measuring locations on the discharge lines of MV, MOPV, SLPV0 and SLPV1 are adequate for POSRV leakage detection. The analyzed temperature can be used as an alarm setpoint for leakage detection. Spring-Loaded Pilot Valve (SLPV) acts as a Reactor Coolant Pressure Boundary (RCPB) isolator in the closed position during the normal operation, but it opens automatically when the system pressure increases to its set pressure. The POSRVs shall be closed tightly to maintain the integrity of RCPB during the normal operation. Leakage through the RCPB is limited extremely. Each POSRV has several discharge lines for MV and auxiliary valves. Temperature instruments are installed on each discharge lines for leakage detection. In this study, Computational Fluid Dynamics (CFD) analyses using FLUENT are conducted to evaluate the temperature measurement for POSRV leakage detection. The followings are concluded from this study: 1) The determined temperature measuring points are adequate for effective leak detection, which are at the downstream of the first bend of each discharge line as close as to the discharge nozzle. 2) The alarm set point for detecting a leak is adequate and can be determined with considering the analysis results. 3) The temperature rise is sufficiently high to detect a small leakage. 4) The temperature sensing method is appropriate for finding a valve leakage

  14. Numerical study of effect of oxygen fraction on local entropy ...

    Indian Academy of Sciences (India)

    This study considers numerical simulation of the combustion of methane with air, including oxygen and nitrogen, in a burner and the numerical solution of local entropy generation rate due to high temperature and velocity gradients in the combustion chamber. The effects of equivalence ratio () and oxygen percentage () ...

  15. Hand Hygiene Adherence Among Health Care Workers at Japanese Hospitals: A Multicenter Observational Study in Japan.

    Science.gov (United States)

    Sakihama, Tomoko; Honda, Hitoshi; Saint, Sanjay; Fowler, Karen E; Shimizu, Taro; Kamiya, Toru; Sato, Yumiko; Arakawa, Soichi; Lee, Jong Ja; Iwata, Kentaro; Mihashi, Mutsuko; Tokuda, Yasuharu

    2016-03-01

    Although proper hand hygiene among health care workers is an important component of efforts to prevent health care-associated infection, there are few data available on adherence to hand hygiene practices in Japan. The aim of this study was to examine hand hygiene adherence at teaching hospitals in Japan. An observational study was conducted from July to November 2011 in 4 units (internal medicine, surgery, intensive care, and/or emergency department) in 4 geographically diverse hospitals (1 university hospital and 3 community teaching hospitals) in Japan. Hand hygiene practice before patient contact was assessed by an external observer. In a total of 3545 health care worker-patient observations, appropriate hand hygiene practice was performed in 677 (overall adherence, 19%; 95% confidence interval, 18%-20%). Subgroup rates of hand hygiene adherence were 15% among physicians and 23% among nurses. The ranges of adherence were 11% to 25% between hospitals and 11% to 31% between units. Adherence of the nurses and the physicians to hand hygiene was correlated within each hospital. There was a trend toward higher hand hygiene adherence in hospitals with infection control nurses, compared with hospitals without them (29% versus 16%). The hand hygiene adherence in Japanese teaching hospitals in our sample was low, even lower than reported mean values from other international studies. Greater adherence to hand hygiene should be encouraged in Japan.

  16. A numerical study of the Magellan Plume

    Science.gov (United States)

    Palma, Elbio D.; Matano, Ricardo P.

    2012-05-01

    In this modeling study we investigate the dynamical mechanisms controlling the spreading of the Magellan Plume, which is a low-salinity tongue that extends along the Patagonian Shelf. Our results indicate that the overall characteristics of the plume (width, depth, spreading rate, etc.) are primarily influenced by tidal forcing, which manifests through tidal mixing and tidal residual currents. Tidal forcing produces a homogenization of the plume's waters and an offshore displacement of its salinity front. The interaction between tidal and wind-forcing reinforces the downstream and upstream buoyancy transports of the plume. The influence of the Malvinas Current on the Magellan Plume is more dominant north of 50°S, where it increases the along-shelf velocities and generates intrusions of saltier waters from the outer shelf, thus causing a reduction of the downstream buoyancy transport. Our experiments also indicate that the northern limit of the Magellan Plume is set by a high salinity discharge from the San Matias Gulf. Sensitivity experiments show that increments of the wind stress cause a decrease of the downstream buoyancy transport and an increase of the upstream buoyancy transport. Variations of the magnitude of the discharge produce substantial modifications in the downstream penetration of the plume and buoyancy transport. The Magellan discharge generates a northeastward current in the middle shelf, a recirculation gyre south of the inlet and a region of weak currents father north.

  17. EMG Analysis and Sagittal Plane Kinematics of the Two-Handed and Single-Handed Kettlebell Swing: A Descriptive Study.

    Science.gov (United States)

    Van Gelder, Leonard H; Hoogenboom, Barbara J; Alonzo, Bryan; Briggs, Dayna; Hatzel, Brian

    2015-11-01

    Kettlebell (KB) swing exercises have been proposed as a possible method to improve hip and spinal motor control as well as improve power, strength, and endurance. To describe electromyographic (EMG) and sagittal plane kinematics during two KB exercises: the two-handed KB swing (THKS) and the single-handed KB swing (SHKS). In addition, the authors sought to investigate whether or not hip flexor length related to the muscular activity or the kinematics of the exercise. Twenty-three healthy college age subjects participated in this study. Demographic information and passive hip flexor length were recorded for each subject. A maximum voluntary isometric contraction (MVIC) of bilateral gluteus maximus (GMAX), gluteus medius (GMED), and biceps femoris (BF) muscles was recorded. EMG activity and sagittal plane video was recorded during both the THKS and SHKS in a randomized order. Normalized muscular activation of the three studied muscles was calculated from EMG data. During both SHKS and THKS, the average percent of peak MVIC for GMAX was 75.02% ± 55.38, GMED 55.47% ± 26.33, and BF 78.95% ± 53.29. Comparisons of the mean time to peak activation (TTP) for each muscle showed that the biceps femoris was the first muscle to activate during the swings. Statistically significant (p < .05), moderately positive correlations (r = .483 and .417) were found between passive hip flexor length and % MVIC for the GMax during the SHKS and THKS, respectively. The THKS and SHKS provide sufficient muscular recruitment for strengthening of all of the muscles explored. This is the first study to show significant correlations between passive hip flexor length and muscular activation of hip extensors, particularly the GMax. Finally, the BF consistently reached peak activity before the GMax and GMed during the SHKS. Level 3.

  18. Faculty Workshops for Teaching Information Assurance through Hands-On Exercises and Case Studies

    Science.gov (United States)

    Yuan, Xiaohong; Williams, Kenneth; Yu, Huiming; Rorrer, Audrey; Chu, Bei-Tseng; Yang, Li; Winters, Kathy; Kizza, Joseph

    2017-01-01

    Though many Information Assurance (IA) educators agree that hands-on exercises and case studies improve student learning, hands-on exercises and case studies are not widely adopted due to the time needed to develop them and integrate them into curricula. Under the support of the National Science Foundation (NSF) Scholarship for Service program, we…

  19. Unimanual SNARC Effect: Hand Matters.

    Science.gov (United States)

    Riello, Marianna; Rusconi, Elena

    2011-01-01

    A structural representation of the hand embedding information about the identity and relative position of fingers is necessary to counting routines. It may also support associations between numbers and allocentric spatial codes that predictably interact with other known numerical spatial representations, such as the mental number line (MNL). In this study, 48 Western participants whose typical counting routine proceeded from thumb-to-little on both hands performed magnitude and parity binary judgments. Response keys were pressed either with the right index and middle fingers or with the left index and middle fingers in separate blocks. 24 participants responded with either hands in prone posture (i.e., palm down) and 24 participants responded with either hands in supine (i.e., palm up) posture. When hands were in prone posture, the counting direction of the left hand conflicted with the direction of the left-right MNL, whereas the counting direction of the right hand was consistent with it. When hands were in supine posture, the opposite was true. If systematic associations existed between relative number magnitude and an allocentric spatial representation of the finger series within each hand, as predicted on the basis of counting habits, interactions would be expected between hand posture and a unimanual version of the spatial-numerical association of response codes (SNARC) effect. Data revealed that with hands in prone posture a unimanual SNARC effect was present for the right hand, and with hands in supine posture a unimanual SNARC effect was present for the left hand. We propose that a posture-invariant body structural representation of the finger series provides a relevant frame of reference, a within-hand directional vector, that is associated to simple number processing. Such frame of reference can significantly interact with stimulus-response correspondence effects, like the SNARC, that have been typically attributed to the mapping of numbers on a left

  20. Unimanual SNARC Effect: Hand Matters

    Directory of Open Access Journals (Sweden)

    Marianna eRiello

    2011-12-01

    Full Text Available A structural representation of the hand embedding information about the identity and relative position of fingers is necessary to counting routines. It may also support associations between numbers and allocentric spatial codes that predictably interact with other known numerical spatial representations, such as the mental number line. In this study, 48 Western participants whose typical counting routine proceeded from thumb-to-little on both hands performed magnitude and parity binary judgments. Response keys were pressed either with the right index and middle fingers or with the left index and middle fingers in separate blocks. 24 participants responded with either hands in prone posture (i.e. palm down and 24 participants responded with either hands in supine (i.e. palm up posture. When hands were in prone posture, the counting direction of the left hand conflicted with the direction of the left-right mental number line, whereas the counting direction of the right hand was consistent with it. When hands were in supine posture, the opposite was true. If systematic associations existed between relative number magnitude and an allocentric spatial representation of the finger series within each hand, as predicted on the basis of counting habits, interactions would be expected between hand posture and a unimanual version of the Spatial-Numerical Association of Response Codes (SNARC effect. Data revealed that with hands in prone posture a unimanual SNARC effect was present for the right hand, and with hands in supine posture a unimanual SNARC effect was present for the left hand. We propose that a posture-invariant body structural representation of the finger series provides a relevant frame of reference, a within-hand directional vector, that is associated to simple number processing. Such frame of reference can significantly interact with stimulus-response correspondence effects that have been attributed to the mapping of numbers on a mental

  1. Study on the groundwater sustainable problem by numerical ...

    Indian Academy of Sciences (India)

    Pengpeng Zhou

    2017-10-07

    Oct 7, 2017 ... system in Zhanjiang, China, this paper presents a numerical modelling study to research groundwater sustainability of ... bility is a feasible method for solving the sus- ...... Singh A 2010 Decision support for on-farm water man-.

  2. Guadalupe River, California, Sedimentation Study. Numerical Model Investigation

    National Research Council Canada - National Science Library

    Copeland, Ronald

    2002-01-01

    A numerical model study was conducted to evaluate the potential impact that the Guadalupe River flood-control project would have on channel stability in terms of channel aggradation and degradation...

  3. Children's hand hygiene behaviour and available facilities: an observational study in Dutch day care centres.

    Science.gov (United States)

    van Beeck, A H Elise; Zomer, Tizza P; van Beeck, Eduard F; Richardus, Jan Hendrik; Voeten, Helene A C M; Erasmus, Vicki

    2016-04-01

    Children attending day care centres are at increased risk of infectious diseases, in particular gastrointestinal and respiratory infections. Hand hygiene of both caregivers and children is an effective prevention measure. This study examined hand hygiene behaviour of children attending day care centres, and describes hygiene facilities at day care centres. Data were collected at 115 Dutch day care centres, among 2318 children cared for by 231 caregivers (August to October 2010). Children's hand hygiene behaviour was observed and data on hand hygiene facilities of the day care centres collected by direct unobtrusive observation. National guidelines indicate hand hygiene is required before eating, after toilet use and after playing outside. Among 1930 observed hand hygiene opportunities for children, overall adherence to hand hygiene guidelines was 31% (95% CI: 29-33%). Adherence after both toilet use and playing outside was 48%. Hands were less frequently washed before eating, where guideline adherence was 15%. In 38% of the playrooms there was no soap within reach of children and 17% had no towel facilities. In over 40% of the playrooms, appropriate hand hygiene facilities for children were lacking. Adequate hand washing facilities were available for children in only half of the participating day care centres in our study and children washed their hands in only 15-48% of the occasions defined by official guidelines. More attention is needed to hand hygiene of children attending day care centres in the prevention of infectious diseases. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  4. The Adriatic response to the bora forcing. A numerical study

    International Nuclear Information System (INIS)

    Rachev, N.

    2001-01-01

    This paper deals with the bora wind effect on the Adriatic Sea circulation as simulated by a 3-D numerical code (the DieCAST model). The main result of this forcing is the formation of intense upwelling along the eastern coast in agreement with previous theoretical studies and observations. Different numerical experiments are discussed for various boundary and initial conditions to evaluate their influence on both circulation and upwelling patterns

  5. Environmental factors and their association with emergency department hand hygiene compliance: an observational study.

    Science.gov (United States)

    Carter, Eileen J; Wyer, Peter; Giglio, James; Jia, Haomiao; Nelson, Germaine; Kauari, Vepuka E; Larson, Elaine L

    2016-05-01

    Hand hygiene is effective in preventing healthcare-associated infections. Environmental conditions in the emergency department (ED), including crowding and the use of non-traditional patient care areas (ie, hallways), may pose barriers to hand hygiene compliance. We examined the relationship between these environmental conditions and proper hand hygiene. This was a single-site, observational study. From October 2013 to January 2014, trained observers recorded hand hygiene compliance among staff in the ED according to the World Health Organization 'My 5 Moments for Hand Hygiene'. Multivariable logistic regression was used to analyse the relationship between environmental conditions and hand hygiene compliance, while controlling for important covariates (eg, hand hygiene indication, glove use, shift, etc). A total of 1673 hand hygiene opportunities were observed. In multivariable analyses, hand hygiene compliance was significantly lower when the ED was at its highest level of crowding than when the ED was not crowded and lower among hallway care areas than semiprivate care areas (OR=0.39, 95% CI 0.28 to 0.55; OR=0.73, 95% CI 0.55 to 0.97). Unique environmental conditions pose barriers to hand hygiene compliance in the ED setting and should be considered by ED hand hygiene improvement efforts. Further study is needed to evaluate the impact of these environmental conditions on actual rates of infection transmission. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. Design, data, and theory regarding a digital hand inclinometer: a portable device for studying slant perception.

    Science.gov (United States)

    Li, Zhi; Durgin, Frank H

    2011-06-01

    Palm boards are often used as a nonverbal measure in human slant perception studies. It was recently found that palm boards are biased and relatively insensitive measures, and that an unrestricted hand gesture provides a more sensitive response (Durgin, Hajnal, Li, Tonge, & Stigliani, Acta Psychologica, 134, 182-197, 2010a). In this article, we describe an original design for a portable lightweight digital device for measuring hand orientation. This device is microcontroller-based and uses a micro inclinometer chip as its inclination sensor. The parts are fairly inexpensive. This device, used to measure hand orientation, provides a sensitive nonverbal method for studying slant perception, which can be used in both indoor and outdoor environments. We present data comparing the use of a free hand to palm-board and verbal measures for surfaces within reach and explain how to interpret free-hand measures for outdoor hills.

  7. Numerical Study on Critical Wedge Angle of Cellular Detonation Reflections

    International Nuclear Information System (INIS)

    Gang, Wang; Kai-Xin, Liu; De-Liang, Zhang

    2010-01-01

    The critical wedge angle (CWA) for the transition from regular reflection (RR) to Mach reflection (MR) of a cellular detonation wave is studied numerically by an improved space-time conservation element and solution element method together with a two-step chemical reaction model. The accuracy of that numerical way is verified by simulating cellular detonation reflections at a 19.3° wedge. The planar and cellular detonation reflections over 45°–55° wedges are also simulated. When the cellular detonation wave is over a 50° wedge, numerical results show a new phenomenon that RR and MR occur alternately. The transition process between RR and MR is investigated with the local pressure contours. Numerical analysis shows that the cellular structure is the essential reason for the new phenomenon and the CWA of detonation reflection is not a certain angle but an angle range. (fundamental areas of phenomenology(including applications))

  8. Improving physician hand hygiene compliance using behavioural theories: a study protocol

    Directory of Open Access Journals (Sweden)

    Squires Janet E

    2013-02-01

    Full Text Available Abstract Background Healthcare-associated infections affect 10% of patients in Canadian acute-care hospitals and are significant and preventable causes of morbidity and mortality among hospitalized patients. Hand hygiene is among the simplest and most effective preventive measures to reduce these infections. However, compliance with hand hygiene among healthcare workers, specifically among physicians, is consistently suboptimal. We aim to first identify the barriers and enablers to physician hand hygiene compliance, and then to develop and pilot a theory-based knowledge translation intervention to increase physicians’ compliance with best hand hygiene practice. Design The study consists of three phases. In Phase 1, we will identify barriers and enablers to hand hygiene compliance by physicians. This will include: key informant interviews with physicians and residents using a structured interview guide, informed by the Theoretical Domains Framework; nonparticipant observation of physician/resident hand hygiene audit sessions; and focus groups with hand hygiene experts. In Phase 2, we will conduct intervention mapping to develop a theory-based knowledge translation intervention to improve physician hand hygiene compliance. Finally, in Phase 3, we will pilot the knowledge translation intervention in four patient care units. Discussion In this study, we will use a behavioural theory approach to obtain a better understanding of the barriers and enablers to physician hand hygiene compliance. This will provide a comprehensive framework on which to develop knowledge translation interventions that may be more successful in improving hand hygiene practice. Upon completion of this study, we will refine the piloted knowledge translation intervention so it can be tested in a multi-site cluster randomized controlled trial.

  9. Prevention of hand eczema among Danish hairdressing apprentices: an intervention study

    DEFF Research Database (Denmark)

    Bregnhøj, Anne; Menné, Torkil; Johansen, Jeanne Duus

    2012-01-01

    for this study and delivered by teachers specially trained in the prevention of hand eczema; the other half received normal training and served as a control group. All apprentices completed self-administered questionnaires including questions regarding hand eczema, use of gloves and degree of wet work, and were...... used gloves during wet work procedures and significantly fewer developed hand eczema compared with apprentices from the control group (p=0.04). A logistic regression model showed that atopic dermatitis had a significant influence on the development of hand eczema in the cohort irrespective...... of the intervention.ConclusionsWe were able to increase the use of gloves and reduce the incidence of hand eczema in hairdressing apprentices by implementing a training program in hairdressing schools....

  10. Analytical and numerical studies of creation probabilities of hierarchical trees

    Directory of Open Access Journals (Sweden)

    S.S. Borysov

    2011-03-01

    Full Text Available We consider the creation conditions of diverse hierarchical trees both analytically and numerically. A connection between the probabilities to create hierarchical levels and the probability to associate these levels into a united structure is studied. We argue that a consistent probabilistic picture requires the use of deformed algebra. Our consideration is based on the study of the main types of hierarchical trees, among which both regular and degenerate ones are studied analytically, while the creation probabilities of Fibonacci, scale-free and arbitrary trees are determined numerically.

  11. Numerical studies of fermionic field theories at large-N

    International Nuclear Information System (INIS)

    Dickens, T.A.

    1987-01-01

    A description of an algorithm, which may be used to study large-N theories with or without fermions, is presented. As an initial test of the method, the spectrum of continuum QCD in 1 + 1 dimensions is determined and compared to previously obtained results. Exact solutions of 1 + 1 dimensional lattice versions of the free fermion theory, the Gross-Neveu model, and QCD are obtained. Comparison of these exact results with results from the numerical algorithm is used to test the algorithms, and more importantly, to determine the errors incurred from the approximations used in the numerical technique. Numerical studies of the above three lattice theories in higher dimensions are also presented. The results are again compared to exact solutions for free fermions and the Gross-Neveu model; perturbation theory is used to derive expansions with which the numerical results for QCD may be compared. The numerical algorithm may also be used to study the euclidean formulation of lattice gauge theories. Results for 1 + 1 dimensional euclidean lattice QCD are compared to the exact solution of this model

  12. The fragrance hand immersion study - an experimental model simulating real-life exposure for allergic contact dermatitis on the hands

    DEFF Research Database (Denmark)

    Heydorn, S; Menné, T; Andersen, Klaus Ejner

    2003-01-01

    hydroxycitronellal or Lyral (hydroxyisohexyl 3-cyclohexene carboxaldehyde). Each participant immersed a finger from each hand, once a day, in a solution containing the fragrance allergen or placebo. During the first 2 weeks, the concentration of fragrance allergen in the solution was low (approximately 10 p...

  13. Comparative assessment of antimicrobial efficacy of different hand sanitizers: An in vitro study.

    Science.gov (United States)

    Jain, Vardhaman Mulchand; Karibasappa, Gundabaktha Nagappa; Dodamani, Arun Suresh; Prashanth, Vishwakarma K; Mali, Gaurao Vasant

    2016-09-01

    To evaluate the antimicrobial efficacy of four different hand sanitizers against Staphylococcus aureus , Staphylococcus epidermidis , Pseudomonas aeruginosa , Escherichia coli , and Enterococcus faecalis as well as to assess and compare the antimicrobial effectiveness among four different hand sanitizers. The present study is an in vitro study to evaluate antimicrobial efficacy of Dettol, Lifebuoy, PureHands, and Sterillium hand sanitizers against clinical isolates of the aforementioned test organisms. The well variant of agar disk diffusion test using Mueller-Hinton agar was used for evaluating the antimicrobial efficacy of hand sanitizers. McFarland 0.5 turbidity standard was taken as reference to adjust the turbidity of bacterial suspensions. Fifty microliters of the hand sanitizer was introduced into each of the 4 wells while the 5 th well incorporated with sterile water served as a control. This was done for all the test organisms and plates were incubated in an incubator for 24 h at 37΀C. After incubation, antimicrobial effectiveness was determined using digital caliper (mm) by measuring the zone of inhibition. The mean diameters of zones of inhibition (in mm) observed in Group A (Sterillium), Group B (PureHands), Group C (Lifebuoy), and Group D (Dettol) were 22 ± 6, 7.5 ± 0.5, 9.5 ± 1.5, and 8 ± 1, respectively. Maximum inhibition was found with Group A against all the tested organisms. Data were statistically analyzed using analysis of variance, followed by post hoc test for group-wise comparisons. The difference in the values of different sanitizers was statistically significant at P hand sanitizer to maintain the hand hygiene.

  14. Hand hygiene instruction decreases illness-related absenteeism in elementary schools: a prospective cohort study

    Science.gov (United States)

    2012-01-01

    Background Illness-related absences have been shown to lead to negative educational and economic outcomes. Both hand washing and hand sanitizer interventions have been shown to be effective in reducing illness-related absences. However, while the importance of hand hygiene in schools is clear, the role of instruction in use is less obvious. The purpose of this study was to compare absenteeism rates among elementary students given access to hand hygiene facilities versus students given both access and short repetitive instruction in use, particularly during influenza season when illness-related absences are at a peak. Methods A hand hygiene intervention was implemented from October to May during the 2009/2010 academic year, including peak flu season, in two Chicago Public Elementary Schools among students grades pre-kindergarten to eighth grade (ages 4–14). Classrooms were systematically assigned to an intervention or control group by grade (cluster design). Hand hygiene facilities (sanitizer and soap) were made available to all students. Students in the intervention group also received short repetitive instruction in hand hygiene every 2 months. Only absences as a result of respiratory or gastrointestinal illness were used to establish illness-related absenteeism rates. Percent absent days were calculated and bivariate analyses were performed to compare percent absent days among students given access to hand hygiene facilities versus students given both access and instruction. Prior to the intervention, teachers’ perceptions of students’ hand hygiene were also evaluated. Teacher perceptions were analysed to describe attitudes and beliefs. Results Data were collected and analysed for 773 students reporting 1,886 absences during the study period (1.73% of total school days). Both the percent total absent days and percent illness-related absent days were significantly lower in the group receiving short instruction during flu season (P = 0.002, P

  15. Numerical and Experimental Study of Pump Sump Flows

    Directory of Open Access Journals (Sweden)

    Wei-Liang Chuang

    2014-01-01

    Full Text Available The present study analyzes pump sump flows with various discharges and gate submergence. Investigations using a three-dimensional large eddy simulation model and an acoustic Doppler velocimeter are performed. Flow patterns and velocity profiles in the approaching flow are shown to describe the flow features caused by various discharges and gate submergence. The variation of a large-scale spanwise vortex behind a sluice gate is examined and discussed. The suction effect on approaching flow near the pipe column is examined using numerical modeling. To gain more understanding of the vortices variation, a comparison between time-averaged and instantaneous flow patterns is numerically conducted. Additionally, swirl angle, a widely used index for evaluating pump efficiency, is experimentally and numerically examined under various flow conditions. The results indicate that the pump becomes less efficient with increasing discharge and gate submergence. The fluctuation of the free surface over the pump sump is also discussed.

  16. Interdisciplinary Study of Numerical Methods and Power Plants Engineering

    Directory of Open Access Journals (Sweden)

    Ioana OPRIS

    2014-08-01

    Full Text Available The development of technology, electronics and computing opened the way for a cross-disciplinary research that brings benefits by combining the achievements of different fields. To prepare the students for their future interdisciplinary approach,aninterdisciplinary teaching is adopted. This ensures their progress in knowledge, understanding and ability to navigate through different fields. Aiming these results, the Universities introduce new interdisciplinary courses which explore complex problems by studying subjects from different domains. The paper presents a problem encountered in designingpower plants. The method of solvingthe problem isused to explain the numerical methods and to exercise programming.The goal of understanding a numerical algorithm that solves a linear system of equations is achieved by using the knowledge of heat transfer to design the regenerative circuit of a thermal power plant. In this way, the outcomes from the prior courses (mathematics and physics are used to explain a new subject (numerical methods and to advance future ones (power plants.

  17. The numerical study of the compressible rising of nuclear fireball at low altitude

    International Nuclear Information System (INIS)

    Wang Lin; Zheng Yi; Cheng Xianyou

    2010-01-01

    To study the evolution of nuclear fireball during the phase of compressible rising, the pressure and density were computed with numerical method. It can be concluded that the distribution of parameters of fireball changed during its rising the pressure in the upper part of fireball increased while the one of lower part decreased. the dilute area lied in the middle of fireball initially moved upward, on the other hand, the gradient of density in the upper and side part increased and is contrary to the changing of density beneath the fireball. The computational results of density agreed with experimental shadow graphs very well. (authors)

  18. A pilot study of robotic-assisted exercise for hand weakness after stroke.

    Science.gov (United States)

    Stein, Joel; Bishop, Joel; Gillen, Glen; Helbok, Raimund

    2011-01-01

    Upper limb paresis is a major source of disability in stroke survivors, and robotic aided exercise therapy is a promising approach to enhance motor abilities. Few devices have been available to provide robotic therapy to the fingers and hand. We report an open-label pilot study of 12 individuals with chronic moderate hemiparesis after stroke who underwent a six-week training program using a hand robotic device. Participants received a total of 18 hours of robotic therapy. Improvements were found in multiple measures of motor performance, including the Upper Extremity Fugl-Meyer, the Motor Activity Log, the Manual Ability Measure-36, and the Jebsen Hand Function Test. All subjects tolerated the treatment well and no complications were observed. We conclude that robotic therapy for hand paresis after stroke is safe and feasible, and that further studies of efficacy are justified by these preliminary results. © 2011 IEEE

  19. Numerical Studies of Homogenization under a Fast Cellular Flow

    KAUST Repository

    Iyer, Gautam

    2012-09-13

    We consider a two dimensional particle diffusing in the presence of a fast cellular flow confined to a finite domain. If the flow amplitude A is held fixed and the number of cells L 2 →∞, then the problem homogenizes; this has been well studied. Also well studied is the limit when L is fixed and A→∞. In this case the solution averages along stream lines. The double limit as both the flow amplitude A→∞and the number of cells L 2 →∞was recently studied [G. Iyer et al., preprint, arXiv:1108.0074]; one observes a sharp transition between the homogenization and averaging regimes occurring at A = L 2. This paper numerically studies a few theoretically unresolved aspects of this problem when both A and L are large that were left open in [G. Iyer et al., preprint, arXiv:1108.0074] using the numerical method devised in [G. A. Pavliotis, A. M. Stewart, and K. C. Zygalakis, J. Comput. Phys., 228 (2009), pp. 1030-1055]. Our treatment of the numerical method uses recent developments in the theory of modified equations for numerical integrators of stochastic differential equations [K. C. Zygalakis, SIAM J. Sci. Comput., 33 (2001), pp. 102-130]. © 2012 Society for Industrial and Applied Mathematics.

  20. Numerical study of microphase separation in gels and random media

    International Nuclear Information System (INIS)

    Uchida, Nariya

    2004-01-01

    Microphase separation in gels and random media is numerically studied using a Ginzburg-Landau model. A random field destroys long-range orientational (lamellar) order and gives rise to a disordered bicontinuous morphology. The dependence of the correlation length on the field strength is distinct from that of random-field magnets

  1. Numerical taxonomic studies of some tribes of Brassicaceae from Egypt

    NARCIS (Netherlands)

    Abdel Khalik, K.; Maesen, van der L.J.G.; Koopman, W.J.M.; Berg, van den R.G.

    2002-01-01

    A systematic study of 45 taxa belonging to 23 genera of tribes Arabideae, Euclidieae, Hesperideae, Lunarieae, Matthioleae and Sisymbrieae of Brassicaceae from Egypt was conducted by means of numerical analysis based on sixty two morphological characters, including vegetative parts, pollen grains and

  2. Numerical Studies of Homogenization under a Fast Cellular Flow

    KAUST Repository

    Iyer, Gautam; Zygalakis, Konstantinos C.

    2012-01-01

    We consider a two dimensional particle diffusing in the presence of a fast cellular flow confined to a finite domain. If the flow amplitude A is held fixed and the number of cells L 2 →∞, then the problem homogenizes; this has been well studied. Also well studied is the limit when L is fixed and A→∞. In this case the solution averages along stream lines. The double limit as both the flow amplitude A→∞and the number of cells L 2 →∞was recently studied [G. Iyer et al., preprint, arXiv:1108.0074]; one observes a sharp transition between the homogenization and averaging regimes occurring at A = L 2. This paper numerically studies a few theoretically unresolved aspects of this problem when both A and L are large that were left open in [G. Iyer et al., preprint, arXiv:1108.0074] using the numerical method devised in [G. A. Pavliotis, A. M. Stewart, and K. C. Zygalakis, J. Comput. Phys., 228 (2009), pp. 1030-1055]. Our treatment of the numerical method uses recent developments in the theory of modified equations for numerical integrators of stochastic differential equations [K. C. Zygalakis, SIAM J. Sci. Comput., 33 (2001), pp. 102-130]. © 2012 Society for Industrial and Applied Mathematics.

  3. Experimental and numerical study of an autonomous flap

    NARCIS (Netherlands)

    Bernhammer, L.O.; Navalkar, S.T.; Sodja, J.; De Breuker, R.; Karpel, M.

    2015-01-01

    This paper presents the experimental and numerical study of an autonomous load alleviation concept using trailing edge flaps. The flaps are autonomous units, which for instance can be used for gust load alleviation. The unit is self-powered and self-actuated through trailing edge tabs which are

  4. Numerical study of cosmic censorship in string theory

    International Nuclear Information System (INIS)

    Gutperle, Michael; Kraus, Per

    2004-01-01

    Recently Hertog, Horowitz, and Maeda have argued that cosmic censorship can be generically violated in string theory in anti-de Sitter spacetime by considering a collapsing bubble of a scalar field whose mass saturates the Breitenlohner-Freedman bound. We study this system numerically, and find that black holes form rather than naked singularities, implying that cosmic censorship is upheld. (author)

  5. Numerical study of cosmic censorship in string theory

    Energy Technology Data Exchange (ETDEWEB)

    Gutperle, Michael E-mail: gutperle@physics.ucla.edu; Kraus, Per

    2004-04-01

    Recently Hertog, Horowitz, and Maeda have argued that cosmic censorship can be generically violated in string theory in anti-de Sitter spacetime by considering a collapsing bubble of a scalar field whose mass saturates the Breitenlohner-Freedman bound. We study this system numerically, and find that black holes form rather than naked singularities, implying that cosmic censorship is upheld. (author)

  6. Hand hygiene instruction decreases illness-related absenteeism in elementary schools: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Lau Claudia H

    2012-05-01

    Full Text Available Abstract Background Illness-related absences have been shown to lead to negative educational and economic outcomes. Both hand washing and hand sanitizer interventions have been shown to be effective in reducing illness-related absences. However, while the importance of hand hygiene in schools is clear, the role of instruction in use is less obvious. The purpose of this study was to compare absenteeism rates among elementary students given access to hand hygiene facilities versus students given both access and short repetitive instruction in use, particularly during influenza season when illness-related absences are at a peak. Methods A hand hygiene intervention was implemented from October to May during the 2009/2010 academic year, including peak flu season, in two Chicago Public Elementary Schools among students grades pre-kindergarten to eighth grade (ages 4–14. Classrooms were systematically assigned to an intervention or control group by grade (cluster design. Hand hygiene facilities (sanitizer and soap were made available to all students. Students in the intervention group also received short repetitive instruction in hand hygiene every 2 months. Only absences as a result of respiratory or gastrointestinal illness were used to establish illness-related absenteeism rates. Percent absent days were calculated and bivariate analyses were performed to compare percent absent days among students given access to hand hygiene facilities versus students given both access and instruction. Prior to the intervention, teachers’ perceptions of students’ hand hygiene were also evaluated. Teacher perceptions were analysed to describe attitudes and beliefs. Results Data were collected and analysed for 773 students reporting 1,886 absences during the study period (1.73% of total school days. Both the percent total absent days and percent illness-related absent days were significantly lower in the group receiving short instruction during flu season (P

  7. Hand Grip Strength: age and gender stratified normative data in a population-based study

    Directory of Open Access Journals (Sweden)

    Taylor Anne W

    2011-04-01

    Full Text Available Abstract Background The North West Adelaide Health Study is a representative longitudinal cohort study of people originally aged 18 years and over. The aim of this study was to describe normative data for hand grip strength in a community-based Australian population. Secondary aims were to investigate the relationship between body mass index (BMI and hand grip strength, and to compare Australian data with international hand grip strength norms. Methods The sample was randomly selected and recruited by telephone interview. Overall, 3 206 (81% of those recruited participants returned to the clinic during the second stage (2004-2006 which specifically focused on the collection of information relating to musculoskeletal conditions. Results Following the exclusion of 435 participants who had hand pain and/or arthritis, 1366 men and 1312 women participants provided hand grip strength measurement. The study population was relatively young, with 41.5% under 40 years; and their mean BMI was 28.1 kg/m2 (SD 5.5. Higher hand grip strength was weakly related to higher BMI in adults under the age of 30 and over the age of 70, but inversely related to higher BMI between these ages. Australian norms from this sample had amongst the lowest of the hand grip strength of the internationally published norms, except those from underweight populations. Conclusions This population demonstrated higher BMI and lower grip strength in younger participants than much of the international published, population data. A complete exploration of the relationship between BMI and hand grip strength was not fully explored as there were very few participants with BMI in the underweight range. The age and gender grip strength values are lower in younger adults than those reported in international literature.

  8. A quasi-experimental study to determine the effects of a multifaceted educational intervention on hand hygiene compliance in a radiography unit.

    Science.gov (United States)

    O'Donoghue, Margaret; Ng, Suk-Hing; Suen, Lorna Kp; Boost, Maureen

    2016-01-01

    Whilst numerous studies have investigated nurses' compliance with hand hygiene and use of alcohol-based hand rub (ABHR), limited attention has been paid to these issues in allied health staff. Reports have linked infections to breaches in infection control in the radiography unit (RU). With advances in medical imaging, a higher proportion of patients come into contact with RU staff increasing the need for good hand hygiene compliance. This study aimed to evaluate effectiveness on compliance of an intervention to improve awareness of hand hygiene in the RU of a district hospital. A quasi-experimental study design including questionnaires assessing knowledge and attitudes of hand hygiene and direct observation of participants was used to evaluate an educational programme on hand hygiene of the RU of a large district hospital. All healthcare workers (HCW), comprising 76 radiographers, 17 nurses, and nine healthcare assistants (HCA), agreed to participate in the study. Of these, 85 completed the initial and 76 the post-test anonymous questionnaire. The hand hygiene compliance of all 102 HCW was observed over a 3-week period prior to and after the intervention. The 2-month intervention consisted of talks on hand hygiene and benefits of ABHR, provision of visual aids, wall-mounted ABHR dispensers, and personal bottles of ABHR. Before the intervention, overall hand hygiene compliance was low (28.9 %). Post-intervention, compliance with hand hygiene increased to 51.4 %. This improvement was significant for radiographers and HCA. Additionally, knowledge and attitudes improved in particular, understanding that ABHR can largely replace handwashing and there is a need to perform hand hygiene after environmental contact. The increased use of ABHR allowed HCW to feel they had enough time to perform hand hygiene. The educational intervention led to increased awareness of hand hygiene opportunities and better acceptance of ABHR use. The reduced time needed to perform hand

  9. A quasi-experimental study to determine the effects of a multifaceted educational intervention on hand hygiene compliance in a radiography unit

    Directory of Open Access Journals (Sweden)

    Margaret O’Donoghue

    2016-10-01

    Full Text Available Abstract Background Whilst numerous studies have investigated nurses’ compliance with hand hygiene and use of alcohol-based hand rub (ABHR, limited attention has been paid to these issues in allied health staff. Reports have linked infections to breaches in infection control in the radiography unit (RU. With advances in medical imaging, a higher proportion of patients come into contact with RU staff increasing the need for good hand hygiene compliance. This study aimed to evaluate effectiveness on compliance of an intervention to improve awareness of hand hygiene in the RU of a district hospital. Methods A quasi-experimental study design including questionnaires assessing knowledge and attitudes of hand hygiene and direct observation of participants was used to evaluate an educational programme on hand hygiene of the RU of a large district hospital. All healthcare workers (HCW, comprising 76 radiographers, 17 nurses, and nine healthcare assistants (HCA, agreed to participate in the study. Of these, 85 completed the initial and 76 the post-test anonymous questionnaire. The hand hygiene compliance of all 102 HCW was observed over a 3-week period prior to and after the intervention. The 2-month intervention consisted of talks on hand hygiene and benefits of ABHR, provision of visual aids, wall-mounted ABHR dispensers, and personal bottles of ABHR. Results Before the intervention, overall hand hygiene compliance was low (28.9 %. Post-intervention, compliance with hand hygiene increased to 51.4 %. This improvement was significant for radiographers and HCA. Additionally, knowledge and attitudes improved in particular, understanding that ABHR can largely replace handwashing and there is a need to perform hand hygiene after environmental contact. The increased use of ABHR allowed HCW to feel they had enough time to perform hand hygiene. Conclusions The educational intervention led to increased awareness of hand hygiene opportunities and better

  10. The efficacy of peloid therapy in management of hand osteoarthritis: a pilot study

    Science.gov (United States)

    Kasapoğlu Aksoy, Meliha; Altan, Lale; Eröksüz, Rıza; Metin Ökmen, Burcu

    2017-12-01

    Hand osteoarthritis (OA) is associated with pain, reduced grip strength, loss of range of motion (ROM), and joint stiffness, leading to impaired hand function and difficulty in performance of daily living activities. Mud bath therapy has been reported to play a primary role in the prevention and management of OA. Thus, we planned to conduct a study aimed at investigating the effects of peloid therapy on pain, functional state, grip strength, and the quality of life and performing a comparative analysis of the outcomes of peloid therapy. In this randomized, controlled, single-blind, pilot study, patients ( n = 33) underwent peloid therapy over 2 weeks, 5 sessions a week, for a total of 10 sessions and home exercise program in group 1. Patients in group 2 (control, n = 30) received only the same home exercise program as in group 1. Patients were evaluated just before, and 2 and 6 weeks after the start of the study with Visual Analogue Scale (VAS), Australian/Canadian Hand Osteoarthritis Index (AUSCAN), Health Assessment Questionnaire (HAQ), hand grip strength (HGS), and pinch strength (PS). Statistically significant improvements were observed in all parameters assessed at week 2 and week 6 in the group 1 ( p management of symptomatic osteoarthritis of the hand and may provide effective pain control and improvements in the hand functions, quality of life, and grip strength.

  11. Numerical simulation of gas metal arc welding parametrical study

    International Nuclear Information System (INIS)

    Szanto, M.; Gilad, I.; Shai, I.; Quinn, T.P.

    2002-01-01

    The Gas Metal Arc Welding (GMAW) is a widely used welding process in the industry. The process variables are usually determined through extensive experiments. Numerical simulation, reduce the cost and extends the understanding of the process. In the present work, a versatile model for numerical simulation of GMAW is presented. The model provides the basis for fundamental understanding of the process. The model solves the magneto-hydrodynamic equations for the flow and temperature fields of the molten electrode and the plasma simultaneously, to form a fully coupled model. A commercial CFD code was extended to include the effects of radiation, Lorentz forces, Joule heating and thermoelectric effects. The geometry of the numerical model assembled to fit an experimental apparatus. To demonstrate the method, an aluminum electrode was modeled in a pure argon arc. Material properties and welding parameters are the input variables in the numerical model. In a typical process, the temperature distribution of the plasma is over 15000 K, resulting high non-linearity of the material properties. Moreover, there is high uncertainty in the available property data, at that range of temperatures. Therefore, correction factors were derived for the material properties to adjust between the numerical and the experimental results. Using the compensated properties, parametric study was performed. The effects of the welding parameters on the process, such the working voltage, electrode feed rate and shielding gas flow, were derived. The principal result of the present work is the ability to predict, by numerical simulation, the mode, size and frequency of the metal transferred from the electrode, which is the main material and energy source for the welding pool in GMAW

  12. Biofouling in forward osmosis systems: An experimental and numerical study.

    Science.gov (United States)

    Bucs, Szilárd S; Valladares Linares, Rodrigo; Vrouwenvelder, Johannes S; Picioreanu, Cristian

    2016-12-01

    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Biofouling in forward osmosis systems: An experimental and numerical study

    KAUST Repository

    Bucs, Szilard

    2016-09-20

    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling. © 2016 Elsevier Ltd

  14. The cortical activation pattern by a rehabilitation robotic hand: a functional NIRS study.

    Science.gov (United States)

    Chang, Pyung-Hun; Lee, Seung-Hee; Gu, Gwang Min; Lee, Seung-Hyun; Jin, Sang-Hyun; Yeo, Sang Seok; Seo, Jeong Pyo; Jang, Sung Ho

    2014-01-01

    Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS), we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin (HbO), deoxy-hemoglobin (HbR) and total-hemoglobin (HbT) in five regions of interest: the primary sensory-motor cortex (SM1), hand somatotopy of the contralateral SM1, supplementary motor area (SMA), premotor cortex (PMC), and prefrontal cortex (PFC). HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand (uncorrected, p < 0.01). By contrast, HbR value indicated significant activation only in the hand somatotopic area of the left SM1 (uncorrected, p < 0.01). Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

  15. Numerical Study of the Ghost-Ghost-Gluon Vertex on the Lattice

    International Nuclear Information System (INIS)

    Mihara, A.; Cucchieri, A.; Mendes, T.

    2004-01-01

    It is well known that, in Landau gauge, the renormalization function of the ghost-ghost-gluon vertex Z-tilde1 (p2) is finite and constant, at least to all orders of perturbation theory. On the other hand, a direct non-perturbative verification of this result using numerical simulations of lattice QCD is still missing. Here we present a preliminary numerical study of the ghost-ghost-gluon vertex and of its corresponding renormalization function using Monte Carlo simulations in SU(2) lattice Landau gauge. Data were obtained in 4 dimensions for lattice couplings β = 2.2, 2.3, 2.4 and lattice sides N = 4, 8, 16

  16. Numerical study of the ghost-ghost-gluon vertex on the lattice

    International Nuclear Information System (INIS)

    Mihara, A.; Cucchieri, A.; Mendes, T.

    2004-01-01

    It is well known that, in Landau gauge, the renormalization function of the ghost-ghost-gluon vertex Z∼ 1 1(p 2 ) is finite and constant, at least to all orders of perturbation theory. On the other hand, a direct non-perturbative verification of this result using numerical simulations of lattice QCD is still missing. Here we present a preliminary numerical study of the ghost-ghost-gluon vertex and of its corresponding renormalization function using Monte Carlo simulations in SU(2) lattice Landau gauge. Data were obtained in 4 dimensions for lattice couplings β= 2.2, 2.3, 2.4 and lattice sides N = 4, 8, 16. (author)

  17. Numerical and experimental study of two turbulent opposed plane jets

    Energy Technology Data Exchange (ETDEWEB)

    Besbes, Sonia; Mhiri, Hatem [Laboratoire de Mecanique des Fluides et Thermique, Ecole Nationale d' Ingenieurs de Monastir, Route de Ouardanine, Monastir (Tunisia); Le Palec, Georges; Bournot, Philippe [Institut de Mecanique de Marseille, UNIMECA, Technopole de Chateau-Gombert, 60 rue Joliot-Curie, 13453 Marseille (France)

    2003-09-01

    The turbulent interaction between two opposed plane jets separated by a distance H is experimentally studied by using a PIV (Particle Image Velocimetry) method and numerically investigated by means of a finite volume code. Two turbulence models have been tested: the standard k-{epsilon} model and a second-order model. The validation of the numerical study was performed by comparing the results with experimental data obtained for the case of two interacting opposed jets at ambient temperature (isothermal case). The effect of the angle of inclination of the jets is studied. Conclusions of the validation are then used to study the interaction between two jets, one being maintained at ambient temperature whereas the other is heated. Results show that the stagnation point moves towards the heated jet. It is shown that the heating induces a stabilizing effect on the flow. (orig.)

  18. Effect of object functions on tomographic reconstruction a numerical study

    International Nuclear Information System (INIS)

    Babu Rao, C.; Baldev Raj; Ravichandran, V.S.; Munshi, P.

    1996-01-01

    Convolution back projection is the most widely used algorithm of computed tomography (CT). Theoretical studies show that under ideal conditions, the error in the reconstruction can be correlated with the second fourier space derivative of filter function and with the Laplacian of the object function. This paper looks into the second aspect of the error function. In this paper a systematic numerical study is presented on the effect to object functions on global and local errors. (author)

  19. Hand safety for specialty crop production workers: a pilot study investigating frequencies of minor open-wound hand injuries and presence of pathogenic bacteria.

    Science.gov (United States)

    Pate, M L; Nummer, B

    2013-10-01

    The purpose of this study was to quantify the presence of minor open-wound hand injuries in addition to Salmonella, Staphylococcus aureus, coliforms, and Escherichia coli on the hands of farm workers who hand-harvest fruit crops in Utah. Data collection was conducted on four farms without USDA Good Agricultural Practices (GAP) certification and on two farms with GAP certification. This study identified essential safety issues that need to be addressed for improving the effectiveness of safety training for migrant farm workers. Farms that have a food safety audit program in place are less likely to have farm workers exposed to pathogenic bacteria and open-wound injuries to their hands. High frequency of S. aureus may indicate a potentially higher risk for wound infection within this worker population. This could lead to infections that are resistant to the antibiotics commonly used to treat ordinary staph infections, resulting in greater work loss time and medical expenses for these workers. Higher frequencies of bacterial presence on workers' hands on non-certified farms indicate a need to identify essential practices to improve worker hygiene habits and on-farm management practices to promote healthy hygiene. Open-wound injuries to migrant farm workers during hand-harvesting could create additional health problems with the possibility of infection and the spread of diseases. Continued research is needed to understand workers' acceptance of these injuries and barriers to personal protection.

  20. Numerical Studies of a Fluidic Diverter for Flow Control

    Science.gov (United States)

    Gokoglu, Suleyman A.; Kuczmarski, Maria A.; Culley, Dennis E.; Raghu, Surya

    2009-01-01

    The internal flow structure in a specific fluidic diverter is studied over a range from low subsonic to sonic inlet conditions by a time-dependent numerical analysis. The understanding will aid in the development of fluidic diverters with minimum pressure losses and advanced designs of flow control actuators. The velocity, temperature and pressure fields are calculated for subsonic conditions and the self-induced oscillatory behavior of the flow is successfully predicted. The results of our numerical studies have excellent agreement with our experimental measurements of oscillation frequencies. The acoustic speed in the gaseous medium is determined to be a key factor for up to sonic conditions in governing the mechanism of initiating the oscillations as well as determining its frequency. The feasibility of employing plasma actuation with a minimal perturbation level is demonstrated in steady-state calculations to also produce oscillation frequencies of our own choosing instead of being dependent on the fixed-geometry fluidic device.

  1. Numerical study of dense adjoint 2-color matter

    International Nuclear Information System (INIS)

    Hands, S.; Scorzato, L.; Oevers, M.

    2000-11-01

    We study the global symmetries of SU(2) gauge theory with N flavors of staggered fermions in the presence of a chemical potential. We motivate the special interest of the case N=1 (staggered) with fermions in the adjoint representation of the gauge group. We present results from numerical simulations with both hybrid Monte Carlo and the two-step multi-bosonic algorithm. (orig.)

  2. Numerical study of ion thermal gradient driven modes

    International Nuclear Information System (INIS)

    Garbet, X.; Laurent, L.; Mourgues, F.; Samain, A.

    1987-01-01

    Anomalous ion thermal confinement has been observed in tokamaks (1). The ion temperature gradient driven modes could provide a possible explanation of this fact. The goal of this paper is to examine the stability of such modes by a linear, analytical and numerical study. The value of the threshold parameter and the radial profiles of the modes are computed. The effects of the particles vertical drift due to the field curvature are discussed

  3. Dispersion of helically corrugated waveguides: Analytical, numerical, and experimental study

    International Nuclear Information System (INIS)

    Burt, G.; Ronald, K.; Young, A.R.; Phelps, A.D.R.; Cross, A.W.; Konoplev, I.V.; He, W.; Thomson, J.; Whyte, C.G.; Samsonov, S.V.; Denisov, G.G.; Bratman, V.L.

    2004-01-01

    Helically corrugated waveguides have recently been studied for use in various applications such as interaction regions in gyrotron traveling-wave tubes and gyrotron backward-wave oscillators and as a dispersive medium for passive microwave pulse compression. The paper presents a summary of various methods that can be used for analysis of the wave dispersion of such waveguides. The results obtained from an analytical approach, simulations with the three-dimensional numerical code MAGIC, and cold microwave measurements are analyzed and compared

  4. Numerical study of droplet impact and rebound on superhydrophobic surface

    Science.gov (United States)

    Cai, Xuan; Wu, Yanchen; Woerner, Martin; Frohnapfel, Bettina

    2017-11-01

    Droplet impact and rebound on superhydrophobic surface is an important process in many applications; among them are developing self-cleaning or anti-icing materials and limiting liquid film formation of Diesel Exhaust Fluid (DEF) in exhaust gas pipe. In the latter field, rebound of DEF droplet from wall is desired as an effective mean for avoiding or reducing unwanted solid deposition. Our goal is to numerically study influence of surface wettability on DEF droplet impact and rebound behavior. A phase-field method is chosen, which was implemented in OpenFOAM by us and validated for wetting-related interfacial flow problems. In the present contribution we first numerically reproduce relevant experimental studies in literature, to validate the code for droplet impact and rebound problem. There we study droplet-surface contact time, maximum/instantaneous spreading factor and droplet shape evolution. Our numerical results show good agreement with experimental data. Next we investigate for DEF droplets the effects of diameter, impact velocity and surface wettability on rebound behavior and jumping height. Based on Weber number and equilibrium contact angle, two regimes are identified. We show that surface wettability is a deciding factor for achieving rebound event. This work is supported by Foundation ``Friedrich-und-Elisabeth Boysen Stiftung fuer Forschung und Innovation'' (BOY-127-TP1).

  5. Numerical studies of Siberian snakes and spin rotators for RHIC

    International Nuclear Information System (INIS)

    Luccio, A.

    1995-01-01

    For the program of polarized protons in RHIC, two Siberian snakes and four spin rotators per ring will be used. The Snakes will produce a complete spin flip. Spin Rotators, in pairs, will rotate the spin from the vertical direction to the horizontal plane at a given insertion, and back to the vertical after the insertion. Snakes, 180 degrees apart and with their axis of spin precession at 90 degrees to each other, are an effective means to avoid depolarization of the proton beam in traversing resonances. Classical snakes and rotators are made with magnetic solenoids or with a sequence of magnetic dipoles with fields alternately directed in the radial and vertical direction. Another possibility is to use helical magnets, essentially twisted dipoles, in which the field, transverse the axis of the magnet, continuously rotates as the particles proceed along it. After some comparative studies, the authors decided to adopt for RHIC an elegant solution with four helical magnets both for the snakes and the rotators proposed by Shatunov and Ptitsin. In order to simplify the construction of the magnets and to minimize cost, four identical super conducting helical modules will be used for each device. Snakes will be built with four right-handed helices. Spin rotators with two right-handed and two left-handed helices. The maximum field will be limited to 4 Tesla. While small bore helical undulators have been built for free electron lasers, large super conducting helical magnets have not been built yet. In spite of this difficulty, this choice is dictated by some distinctive advantages of helical over more conventional transverse snakes/rotators: (i) the devices are modular, they can be built with arrangements of identical modules, (ii) the maximum orbit excursion in the magnet is smaller, (iii) orbit excursion is independent from the separation between adjacent magnets, (iv) they allow an easier control of the spin rotation and the orientation of the spin precession axis

  6. RAPID3 scores and hand outcome measurements in RA patients: a preliminary study.

    Science.gov (United States)

    Qorolli, Merita; Hundozi-Hysenaj, Hajrije; Rexhepi, Sylejman; Rehxepi, Blerta; Grazio, Simeon

    2017-06-01

    The Routine Assessment of Patient Index Data 3 (RAPID3) is a patient-reported disease activity measure used to assess physical function, pain, and global health in patients with rheumatoid arthritis (RA) without formal joint counts. Since hand involvement and its decreased function are hallmarks of RA, the aim of our study was to investigate the performance of RAPID3 scores with regard to hand function and to confirm previous findings that the RAPID3 score as a disease activity measure is strongly correlated with the DAS28 score. Sixty-eight consecutive patients with RA (85% female), aged 18-75 years, were included in the study and were recruited during their outpatient visit. Apart from demographic and clinical data, the obtained parameters of interest included RAPID3 scores and assessments of the function of the hand, namely, the signal of functional impairment (SOFI)-hand, grip strength, and pulp-to-palm distance, as well the Health Assessment Questionnaire- Disability Index (HAQ-DI) and DAS28 scores. Pearson's correlation coefficient, Student's t test and linear regression were used in the statistical analysis of the results. The significance was set to p < 0.05. A positive correlation was found between RAPID3 scores and HAQ-DI scores, SOFI-hand scores, and pulp-to-palm distance, and negative correlation was observed between RAPID3 scores and grip strength. The order regarding the strength of correlations between RAPID3 scores and other variables (from the strongest to the weakest) was as follows: HAQ-DI, grip strength, SOFI-hand and pulp-to-palm distance. The hand assessment variables had stronger correlations with RAPID3 scores than with DAS28 scores. Our preliminary study showed that RAPID3 scores were strongly correlated with measurements of the functional ability of the hand, demonstrating that RAPID3 can be used as a measure of disease activity in clinical practice and to characterize hand function. Further studies are needed to confirm this result.

  7. Numerical study on discharge process of microcavity plasma

    International Nuclear Information System (INIS)

    Xia Guangqing; Xue Weihua; Wang Dongxue; Zhu Guoqiang; Zhu Yu

    2012-01-01

    The evolution of plasma parameters during high pressure discharge in the microcavity with a hollow anode was numerically studied, with a two-dimensional self-consistent fluid model. The simulations were performed with argon at 13.3 kPa. The numerical results show that during the discharge the electric field around the cathode transforms from an axial field to a radial field, the plasma density gets the maximum value on the central line of the cavity and the location of the maximum density moves from the region near anode at the initial stage to the cathode vicinity at the stable stage, and the maximum electron temperature occurs in the ring sheath of cathode. (authors)

  8. Numerical studies of film formation in context of steel coating

    Science.gov (United States)

    Aniszewski, Wojciech; Zaleski, Stephane; Popinet, Stephane

    2017-11-01

    In this work, we present a detailed example of numerical study of film formation in the context of metal coating. Liquid metal is drawn from a reservoir onto a retracting solid sheet, forming a coating film characterized by phenomena such as longitudinal thickness variation (in 3D) or waves akin to that predicted by Kapitza and Kapitza (visible in two dimensions as well). While the industry standard configuration for Zinc coating is marked by coexistence of medium Capillary number (Ca = 0.03) and film Reynolds number above 1000, we present also parametric studies in order to establish more clearly to what degree does the numerical method influence film regimes obtained in the target configuration. The simulations have been performed using Basilisk, a grid-adapting, strongly optimized code derived from Gerris . Mesh adaptation allows for arbitrary precision in relevant regions such as the contact line or the meniscus, while a coarse grid is applied elsewhere. This adaptation strategy, as the results indicate, is the only realistic approach for numerical method to cover the wide range of necessary scales from the predicted film thickness (hundreds of microns) to the domain size (meters).

  9. Analytical and Numerical Studies of Sloshing in Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Solaas, F

    1996-12-31

    For oil cargo ship tanks and liquid natural gas carriers, the dimensions of the tanks are often such that the highest resonant sloshing periods and the ship motions are in the same period range, which may cause violent resonant sloshing of the liquid. In this doctoral thesis, linear and non-linear analytical potential theory solutions of the sloshing problem are studied for a two-dimensional rectangular tank and a vertical circular cylindrical tank, using perturbation technique for the non-linear case. The tank is forced to oscillate harmonically with small amplitudes of sway with frequency in the vicinity of the lowest natural frequency of the fluid inside the tank. The method is extended to other tank shapes using a combined analytical and numerical method. A boundary element numerical method is used to determine the eigenfunctions and eigenvalues of the problem. These are used in the non-linear analytical free surface conditions, and the velocity potential and free surface elevation for each boundary value problem in the perturbation scheme are determined by the boundary element method. Both the analytical method and the combined analytical and numerical method are restricted to tanks with vertical walls in the free surface. The suitability of a commercial programme, FLOW-3D, to estimate sloshing is studied. It solves the Navier-Stokes equations by the finite difference method. The free surface as function of time is traced using the fractional volume of fluid method. 59 refs., 54 figs., 37 tabs.

  10. Analytical and Numerical Studies of Sloshing in Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Solaas, F.

    1995-12-31

    For oil cargo ship tanks and liquid natural gas carriers, the dimensions of the tanks are often such that the highest resonant sloshing periods and the ship motions are in the same period range, which may cause violent resonant sloshing of the liquid. In this doctoral thesis, linear and non-linear analytical potential theory solutions of the sloshing problem are studied for a two-dimensional rectangular tank and a vertical circular cylindrical tank, using perturbation technique for the non-linear case. The tank is forced to oscillate harmonically with small amplitudes of sway with frequency in the vicinity of the lowest natural frequency of the fluid inside the tank. The method is extended to other tank shapes using a combined analytical and numerical method. A boundary element numerical method is used to determine the eigenfunctions and eigenvalues of the problem. These are used in the non-linear analytical free surface conditions, and the velocity potential and free surface elevation for each boundary value problem in the perturbation scheme are determined by the boundary element method. Both the analytical method and the combined analytical and numerical method are restricted to tanks with vertical walls in the free surface. The suitability of a commercial programme, FLOW-3D, to estimate sloshing is studied. It solves the Navier-Stokes equations by the finite difference method. The free surface as function of time is traced using the fractional volume of fluid method. 59 refs., 54 figs., 37 tabs.

  11. The cortical activation pattern by a rehabilitation robotic hand : A functional NIRS study

    Directory of Open Access Journals (Sweden)

    Pyung Hun eChang

    2014-02-01

    Full Text Available Introduction: Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS, we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Methods: Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin(HbO, deoxy-hemoglobin(HbR and total-hemoglobin(HbT in five regions of interest: the primary sensory-motor cortex (SM1, hand somatotopy of the contralateral SM1, supplementary motor area (SMA, premotor cortex (PMC, and prefrontal cortex (PFC. Results: HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand(uncorrected, pConclusions: Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

  12. Surveillance of nosocomial infections: a preliminary study on hand hygiene compliance of healthcare workers.

    Science.gov (United States)

    Brunetti, L; Santoro, E; De Caro, F; Cavallo, P; Boccia, G; Capunzo, M; Motta, O

    2006-06-01

    The observance of hand hygiene compliance is important to reduce cross-infection by micro-organisms. The aim of this preliminary study was to evaluate the level of hand hygiene in healthcare workers from different departments, with particular emphasis on transient flora. The study was conducted in three departments (Surgery, Intensive Care Unit, Obstetrics and Gynecology) of a hospital in Campania, southern Italy. Over a six-month period, 50 healthcare workers were randomly tested. Imprints of palms and fingertips were taken monthly during the morning shift. The number of colonies per plate was counted and transient pathogens were identified. Risk factors for hand contamination were determined. Total flora was found in the following CFU means per palm and per five fingertips (95% CI): Obstetrics and Gynecology [palms 130 CFUs (95% CI 85-180); fingertips 125 CFUs (95% CI 92-160)]; ICU [palms 80 CFUs (95% CI 58-99); fingertips 62 CFUs (95% CI 45-82)]; Surgery [palms 75 CFUs (95% CI 41-120); fingertips 70 CFUs (95% CI 52-90)] Transient flora was found on 39% of healthcare workers' hands. The only factor associated with hand contamination by transient flora was the absence of gloving during healthcare procedure (P = 0.02).

  13. MRSA Incidence and Antibiotic Trends in Urban Hand Infections: A 10-Year Longitudinal Study.

    Science.gov (United States)

    Kistler, Justin M; Thoder, Joseph J; Ilyas, Asif M

    2018-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is the most reported pathogen in hand infections at urban medical centers throughout the country. Antibiotic sensitivity trends are not well known. The purposes of this study were to examine and determine the drug resistance trends for MRSA infections of the hand and to provide recommendations for empiric antibiotic treatment based on sensitivity profiles. A 10-year longitudinal, retrospective chart review was performed on all culture-positive hand infections encountered at a single urban medical center from 2005 to 2014. The proportions of all organisms were calculated for each year and collectively. MRSA infections were additionally subanalyzed for antibiotic sensitivity. A total of 815 culture-positive hand infections were identified. Overall, MRSA grew on culture in 46% of cases. A trend toward decreasing annual MRSA incidence was noted over the 10-year study period. There was a steady increase in polymicrobial infections during the same time. Resistance to clindamycin increased steadily during the 10-year study, starting at 4% in 2008 but growing to 31% by 2014. Similarly, levofloxacin resistance consistently increased throughout the study, reaching its peak at 56% in 2014. The annual incidence of MRSA in hand infections has declined overall but remains the most common pathogen. There has been an alternative increase in the number of polymicrobial infections. MRSA resistance to clindamycin and levofloxacin consistently increased during the study period. Empiric antibiotic therapy for hand infections should not only avoid penicillin and other beta-lactams but should also consider avoiding clindamycin and levofloxacin for empiric treatment.

  14. E-learning may improve adherence to alcohol-based hand rubbing: a cohort study

    DEFF Research Database (Denmark)

    Laustsen, Sussie; Bibby, Bo Martin; Kristensen, Brian

    2009-01-01

    BACKGROUND: Since 2004, we have promoted alcohol-based hand rubbing (HR) with an e-learning program (ELP) among hospital staff. This study sought to determine whether an ELP improves adherence to correct HR. METHODS: This was a cohort study of staff members at Aarhus University Hospital, Skejby, ...

  15. The effect of pregabalin or duloxetine on arthritis pain: a clinical and mechanistic study in people with hand osteoarthritis

    Directory of Open Access Journals (Sweden)

    Sofat N

    2017-10-01

    Full Text Available Nidhi Sofat,1 Abiola Harrison,1 Mark D Russell,1 Salma Ayis,2 Patrick D Kiely,3 Emma H Baker,1 Thomas Richard Barrick,4 Franklyn A Howe4 1Institute for Infection and Immunity, St George’s University of London, 2Division of Health & Social Care Research, King’s Clinical Trials Unit, King’s College London, 3Department of Rheumatology, St George’s University Hospitals NHS Foundation Trust, 4Molecular and Clinical Sciences Research Institute, St George’s University of London, London, UK Abstract: Osteoarthritis (OA is the most prevalent arthritis worldwide and is characterized by chronic pain and impaired physical function. We hypothesized that heightened pain in hand OA could be reduced with duloxetine or pregabalin. In this prospective, randomized clinical study, we recruited 65 participants, aged 40–75 years, with a Numerical Rating Scale (NRS for pain of at least 5. Participants were randomized to one of the following three groups: duloxetine, pregabalin, and placebo. The primary endpoint was the NRS pain score, and the secondary endpoints included the Australian and Canadian Hand Osteoarthritis Index (AUSCAN pain, stiffness, and function scores and quantitative sensory testing by pain pressure algometry. After 13 weeks, compared to placebo, ANOVA found significant differences between the three groups (P=0.0078. In the intention-to-treat analysis, the pregabalin group showed improvement for NRS pain (P=0.023, AUSCAN pain (P=0.008, and AUSCAN function (P=0.009, but no difference between duloxetine and placebo (P>0.05 was observed. In the per protocol analysis, NRS pain was reduced for pregabalin (P<0.0001 and duloxetine (P=0.029 compared to placebo. We conclude that centrally acting analgesics improve pain outcomes in people with hand arthritis, offering new treatment paradigms for OA pain. Keywords: pain, hand osteoarthritis, sensitization, duloxetine, pregabalin

  16. Experimental and numerical study of a printed circuit heat exchanger

    International Nuclear Information System (INIS)

    Chen, Minghui; Sun, Xiaodong; Christensen, Richard N.; Shi, Shanbin; Skavdahl, Isaac; Utgikar, Vivek; Sabharwall, Piyush

    2016-01-01

    Highlights: • A dynamic model is developed for transient analysis of the straight-channel PCHE. • Transient scenarios of the straight-channel PCHE subject to helium temperature and mass flow rate variations are numerically investigated. • Steady-state temperature distribution inside the straight-channel PCHE is obtained in calculation. • Experiments are conducted to study the dynamic behavior of the straight-channel PCHE. - Abstract: Printed circuit heat exchangers (PCHEs) are promising to be employed in very-high-temperature gas-cooled reactors (VHTRs) due to their high robustness for high-temperature, high-pressure applications and high compactness. PCHEs typically serve as intermediate heat exchangers (IHXs) that isolate the secondary loop from the reactor’s primary system and hence must be sufficiently robust to maintain the system integrity during normal and off-normal conditions. In addition, the performance of the PCHE-type IHX could considerably affect the nuclear power plant overall operation since any transients on the secondary side would be propagated back to the reactor’s primary coolant system via the IHX. It is therefore imperative to understand how the PCHE would dynamically respond to a variety of transients. In the current study, experiments were first conducted to examine the steady-state thermal performance of a reduced-scale straight-channel PCHE. A dynamic model benchmarked in a previous study was then used to predict the steady-state and transient behavior of the PCHE. The steady-state temperature profiles of the working fluids on both the hot and cold sides and in the solid plates of the heat exchanger were obtained, which served as the initial condition for the transient simulations. The detailed dynamic response of the straight-channel PCHE, subject to inlet temperature variations, helium mass flow variations, and combinations of the two, was simulated and analyzed. In addition, two sets of transient tests, one for helium inlet

  17. Economic Evaluation of a Multifaceted Implementation Strategy for the Prevention of Hand Eczema Among Healthcare Workers in Comparison with a Control Group: The Hands4U Study.

    Science.gov (United States)

    van der Meer, Esther W C; van Dongen, Johanna M; Boot, Cécile R L; van der Gulden, Joost W J; Bosmans, Judith E; Anema, Johannes R

    2016-05-01

    The aim of this study was to evaluate the cost-effectiveness of a multifaceted implementation strategy for the prevention of hand eczema in comparison with a control group among healthcare workers. A total of 48 departments (n=1,649) were randomly allocated to the implementation strategy or the control group. Data on hand eczema and costs were collected at baseline and every 3 months. Cost-effectiveness analyses were performed using linear multilevel analyses. The probability of the implementation strategy being cost-effective gradually increased with an increasing willingness-to-pay, to 0.84 at a ceiling ratio of €590,000 per person with hand eczema prevented (societal perspective). The implementation strategy appeared to be not cost-effective in comparison with the control group (societal perspective), nor was it cost-beneficial to the employer. However, this study had some methodological problems which should be taken into account when interpreting the results.

  18. On the Numerical and Experimental Study of Spray Cooling

    Directory of Open Access Journals (Sweden)

    M.R. Guechi

    2013-12-01

    Full Text Available The spraying of an impinging jet is an effective way to cool heated surfaces. The objective of this study is to develop a numerical model to predict the heat transfer with phase change between a hot plate surface and a two-phase impinging jet. Different two-phase modeling approaches (Lagrangian and Eulerian methods are compared. The influence of the spray nozzle operating conditions and of the distance between the nozzle exit and the surface impact is analyzed. The numerical results are compared with measurements obtained on an experimental test bench. The confrontation numerical/experimental is carried out by comparing the distribution of temperature at the surface of the plate and the heat transfer coefficient. This comparison shows that it is the Eulerian model which seems most capable to take into account the evaporation of the droplets in contact with the heated plate. However, the simulation performed with this model show a strong dependence of the results to the turbulence model used.

  19. Numerical Study of Aeroacoustic Sound on Performance of Bladeless Fan

    Science.gov (United States)

    Jafari, Mohammad; Sojoudi, Atta; Hafezisefat, Parinaz

    2017-03-01

    Aeroacoustic performance of fans is essential due to their widespread application. Therefore, the original aim of this paper is to evaluate the generated noise owing to different geometric parameters. In current study, effect of five geometric parameters was investigated on well performance of a Bladeless fan. Airflow through this fan was analyzed simulating a Bladeless fan within a 2 m×2 m×4 m room. Analysis of the flow field inside the fan and evaluating its performance were obtained by solving conservations of mass and momentum equations for aerodynamic investigations and FW-H noise equations for aeroacoustic analysis. In order to design Bladeless fan Eppler 473 airfoil profile was used as the cross section of this fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter and aspect ratio for circular and quadratic cross sections were considered. Validating acoustic code results, we compared numerical solution of FW-H noise equations for NACA0012 with experimental results. FW-H model was selected to predict the noise generated by the Bladeless fan as the numerical results indicated a good agreement with experimental ones for NACA0012. To validate 3-D numerical results, the experimental results of a round jet showed good agreement with those simulation data. In order to indicate the effect of each mentioned parameter on the fan performance, SPL and OASPL diagrams were illustrated.

  20. Studies on the Estimation of Stature from Hand and Foot Length of an Individual

    Directory of Open Access Journals (Sweden)

    O. S. Saka

    2016-10-01

    Full Text Available Background: Studies on the estimation of stature from hand and foot length of an individual are essential study in personal identification. Aim and Objectives: This study is to find out correlation between statures with hand and foot dimensions in both sexes and gender comparison from an individual in Lautech Staff College in Ogbomoso and College ogbomoso and College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria. Material and Methods: A sample of 140 students and staff; 70 male and 70 female Students and staff of Lautech Staff College in Ogbomoso and College ogbomoso and College of Health Sciences, Obafemi Awolowo University, Ile-Ife, between 16-35years were considered and measurements were taken for each of the parameters. Gender differences for the two parameters were determined using Student t-test. Pearson's correlation coefficient (r was used to examine the relationship between two anthropometric parameters and standing height (stature. All these measurements were done by using standard anthropometric instruments and standard anthropometric techniques. Results: The findings of the study indicated that the males mean values are not significantly difference when compared with females mean values in all measured parameters. The study showed significant (p<0.001 positive correlation between the stature with hand lengths and foot lengths. The hand and foot length provide accurate and reliable means in establishing the height of an individual. Conclusion: This study will be useful for forensic scientists and anthropologists as well as anatomists in ascertain medico-legal cases

  1. New numerical method to study phase transitions and its applications

    International Nuclear Information System (INIS)

    Lee, Jooyoung; Kosterlitz, J.M.

    1991-11-01

    We present a powerful method of identifying the nature of transitions by numerical simulation of finite systems. By studying the finite size scaling properties of free energy barrier between competing states, we can identify unambiguously a weak first order transition even when accessible system sizes are L/ξ < 0.05 as in the five state Potts model in two dimensions. When studying a continuous phase transition we obtain quite accurate estimates of critical exponents by treating it as a field driven first order transition. The method has been successfully applied to various systems

  2. Numerical studies of transverse curvature effects on transonic flow stability

    Science.gov (United States)

    Macaraeg, M. G.; Daudpota, Q. I.

    1992-01-01

    A numerical study of transverse curvature effects on compressible flow temporal stability for transonic to low supersonic Mach numbers is presented for axisymmetric modes. The mean flows studied include a similar boundary-layer profile and a nonsimilar axisymmetric boundary-layer solution. The effect of neglecting curvature in the mean flow produces only small quantitative changes in the disturbance growth rate. For transonic Mach numbers (1-1.4) and aerodynamically relevant Reynolds numbers (5000-10,000 based on displacement thickness), the maximum growth rate is found to increase with curvature - the maximum occurring at a nondimensional radius (based on displacement thickness) between 30 and 100.

  3. Numerical analysis of data in dynamic function studies

    International Nuclear Information System (INIS)

    Riihimaeki, E.

    1975-01-01

    Relations between tracer theories, models for organ function and the numerical solution of parameters from tracer experiments are reviewed. A unified presentation is given in terms of systems theory. Dynamic tracer studies should give the flow and volume of the tracer and, possibly, indications of the internal structure of the organ studied. Proper program writing will facilitate the exchange of the programs between the users and thereby avoid duplication of effort. An important attribute in this respect is machine independence of the programs which is achieved by the use of a high-level language. (author)

  4. Numerical study of particle filtration in an induction crucible furnace

    International Nuclear Information System (INIS)

    Asad, Amjad; Kratzsch, Christoph; Dudczig, Steffen; Aneziris, Christos G.; Schwarze, Rüdiger

    2016-01-01

    Highlights: • Removing particles from a melt in an induction furnace by using a filter is introduced. • The effect of filter and its permeability on the melt flow is shown. • The impact of filter permeability and particle diameter on filter efficiency is studied. • The filter efficiency depends on filter position and number of the used filter. - Abstract: The present paper deals with a numerical investigation of the turbulent melt flow driven by the electromagnetic force in an induction furnace. The main scope of the paper is to present a new principle to remove non-metallic particles from steel melt in an induction furnace by immersing a porous filter in the melt. The magnetic field acting on the melt is calculated by using the open source software MaxFEM"®, while the turbulent flow is simulated by means of the open source computational fluid dynamics library OpenFOAM"®. The validation of the numerical model is accomplished by using experimental results for the flow without the immersed filter. Here it is shown that the time-averaged flow, obtained numerically is in a good quantitive agreement with the experimental data. Then, the validated numerical model is employed to simulate the melt flow with the immersed filter in the induction furnace of a new type of real steel casting simulator investigated at Technische Universität Bergakademie Freiberg. The considerable effect of the filter on the flow pattern is indicated in the present work. Moreover, it is shown that the filter permeability and its position have a significant influence on the melt flow in the induction furnace. Additionally, particles are injected in the flow domain and tracked by using Lagrangian framework. In this case, the efficiency of the used filter is determined in the present investigation depending on its permeability, its position and the particles diameter.

  5. Iterative co-creation for improved hand hygiene and aseptic techniques in the operating room: experiences from the safe hands study.

    Science.gov (United States)

    Erichsen Andersson, Annette; Frödin, Maria; Dellenborg, Lisen; Wallin, Lars; Hök, Jesper; Gillespie, Brigid M; Wikström, Ewa

    2018-01-04

    Hand hygiene and aseptic techniques are essential preventives in combating hospital-acquired infections. However, implementation of these strategies in the operating room remains suboptimal. There is a paucity of intervention studies providing detailed information on effective methods for change. This study aimed to evaluate the process of implementing a theory-driven knowledge translation program for improved use of hand hygiene and aseptic techniques in the operating room. The study was set in an operating department of a university hospital. The intervention was underpinned by theories on organizational learning, culture and person centeredness. Qualitative process data were collected via participant observations and analyzed using a thematic approach. Doubts that hand-hygiene practices are effective in preventing hospital acquired infections, strong boundaries and distrust between professional groups and a lack of psychological safety were identified as barriers towards change. Facilitated interprofessional dialogue and learning in "safe spaces" worked as mechanisms for motivation and engagement. Allowing for the free expression of different opinions, doubts and viewing resistance as a natural part of any change was effective in engaging all professional categories in co-creation of clinical relevant solutions to improve hand hygiene. Enabling nurses and physicians to think and talk differently about hospital acquired infections and hand hygiene requires a shift from the concept of one-way directed compliance towards change and learning as the result of a participatory and meaning-making process. The present study is a part of the Safe Hands project, and is registered with ClinicalTrials.gov (ID: NCT02983136 ). Date of registration 2016/11/28, retrospectively registered.

  6. Acupuncture in subjects with cold hands sensation: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Seo, Jung-Chul; Lee, Hyun-jong; Kwak, Min-Ah; Park, Sung-Hoon; Shin, ImHee; Yun, Woo-Sung; Park, Kihyuk

    2014-09-04

    Cold hands sensation is a common disorder within the Korean population. Many Korean family physicians believe that it is a mild early manifestation of Raynaud's phenomenon (RP), or may be related to RP. RP is characterized by reversible digital vasospasm provoked by cold temperatures and/or emotional stress, and doctors often prescribe medications that are used in treatment of RP for subjects with cold hands. However, this has not shown a clear benefit, and these medications can cause unwanted side effects. It is also reported that traditional Korean medicine, including acupuncture, is widely used to treat cold hands, although the current level of evidence for this approach is also poor and to date, there have been no published randomized controlled clinical trials (RCTs) evaluating the efficacy and safety of acupuncture for cold hands. We have therefore designed a pilot RCT to obtain information for the design of a further full-scale trial. The proposed study is a five-week pilot RCT. A total of 14 subjects will be recruited and randomly allocated to two groups: an acupuncture plus medication group (experimental group) and a medication-only group (control group). All subjects will take nifedipine (5 mg once daily) and beraprost (20 mg three times daily) for three weeks. The experimental group will receive additional treatment with three acupuncture sessions per week for three weeks (nine sessions total). The primary outcome will be measured using a visual analogue scale. Secondary outcomes will be measured by blood perfusion in laser Doppler perfusion imaging of the hands, frequency and duration of episodes of cold hands, and heart rate variability. Assessments will be made at baseline and at one, three, and five weeks thereafter. This study will provide an indication of the feasibility and a clinical foundation for a future large-scale trial. This study was registered at Korean Clinical Research Information Service (CRIS) registry on 5 August 2013 with the

  7. Agent Orange Exposure and Monoclonal Gammopathy of Undetermined Significance: An Operation Ranch Hand Veteran Cohort Study.

    Science.gov (United States)

    Landgren, Ola; Shim, Youn K; Michalek, Joel; Costello, Rene; Burton, Debra; Ketchum, Norma; Calvo, Katherine R; Caporaso, Neil; Raveche, Elizabeth; Middleton, Dan; Marti, Gerald; Vogt, Robert F

    2015-11-01

    Multiple myeloma has been classified as exhibiting "limited or suggestive evidence" of an association with exposure to herbicides in Vietnam War veterans. Occupational studies have shown that other pesticides (ie, insecticides, herbicides, fungicides) are associated with excess risk of multiple myeloma and its precursor state, monoclonal gammopathy of undetermined significance (MGUS); however, to our knowledge, no studies have uncovered such an association in Vietnam War veterans. To examine the relationship between MGUS and exposure to Agent Orange, including its contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in Vietnam War veterans. This was a prospective cohort study conducted in 2013 to 2014, testing for MGUS in serum specimens collected and stored in 2002 by the Air Force Health Study (AFHS). The relevant exposure data collected by the AFHS was also used. We tested all specimens in 2013 without knowledge of the exposure status. The AFHS included former US Air Force personnel who participated in Operation Ranch Hand (Ranch Hand veterans) and other US Air Force personnel who had similar duties in Southeast Asia during the same time period (1962 to 1971) but were not involved in herbicide spray missions (comparison veterans). Agent Orange was used by the US Air Force personnel who conducted aerial spray missions of herbicides (Operation Ranch Hand) in Vietnam from 1962 to 1971. We included 479 Ranch Hand veterans and 479 comparison veterans who participated in the 2002 follow-up examination of AFHS. Agent Orange and TCDD. Serum TCDD levels were measured in 1987, 1992, 1997, and 2002. Risk of MGUS measured by prevalence, odds ratios (ORs), and 95% CIs. The 479 Ranch Hand veterans and 479 comparison veterans had similar demographic and lifestyle characteristics and medical histories. The crude prevalence of overall MGUS was 7.1% (34 of 479) in Ranch Hand veterans and 3.1% (15 of 479) in comparison veterans. This translated into a 2.4-fold increased risk

  8. "Sharks in Your Hands"--A Case Study on Effects of Teaching Strategies to Change Knowledge and Attitudes towards Sharks

    Science.gov (United States)

    Lee, Hung-Shan; Liu, Shiang-Yao; Yeh, Ting-Kuang

    2016-01-01

    This study was designed to exemplify how hands-on based teaching strategies enhanced students' knowledge and positive attitudes towards sharks. Hands-on activities for sharks' biological and morphological features were carried out. Eleven elementary school students from a remote area in Taiwan were recruited and assigned to the hands-on condition.…

  9. Numerical and experimental studies of droplet-gas flow

    Energy Technology Data Exchange (ETDEWEB)

    Joesang, Aage Ingebret

    2002-07-01

    This thesis considers droplet-gas flow by the use of numerical methods and experimental verification. A commercial vane separator was studied both numerical and by experiment. In addition some efforts are put into the numerical analysis of cyclones. The experimental part contains detailed measurements of the flow field between a pair of vanes in a vane separator and droplet size measurements. LDA (Laser Doppler Anemometry) was used to measure the velocity in two dimensions and corresponding turbulence quantities. The results from the LDA measurements are considered to be of high quality and are compared to numerical results obtained from a CFD (Computational Fluid Dynamics) analysis. The simulation showed good agreement between the numerical and experimental results. Combinations of different turbulence models; the standard k-epsilon model and the Reynold Stress Mode, different schemes; first order and higher order scheme and different near wall treatment of the turbulence; the Law of the wall and the Two-Layer Zonal model were used in the simulations. The Reynold Stress Model together with a higher order scheme performed rather poorly. The recirculation in parts of the separator was overpredicted in this case. For the other cases the overall predictions are satisfactory. PDA (Phase Doppler Anemometry) measurements were used to study the changes in the droplet size distribution through the vane separator. The PDA measurements show that smaller droplets are found at the outlet than present at the inlet. In the literature there exists different mechanisms for explaining the re-entrainment and generation of new droplets. The re-entrainments mechanisms are divided into four groups where droplet-droplet interaction, droplet break-up, splashing of impinging droplet and re-entrainment from the film are defined as the groups of re-entrainment mechanisms. Models for these groups are found in the literature and these models are tested for re-entrainment using the operational

  10. Numerical study of two-dimensional moist symmetric instability

    Directory of Open Access Journals (Sweden)

    M. Fantini

    2008-06-01

    Full Text Available The 2-D version of the non-hydrostatic fully compressible model MOLOCH developed at ISAC-CNR was used in idealized set-up to study the start-up and finite amplitude evolution of symmetric instability. The unstable basic state was designed by numerical integration of the equation which defines saturated equivalent potential vorticity qe*. We present the structure and growth rates of the linear modes both for a supersaturated initial state ("super"-linear mode and for a saturated one ("pseudo"-linear mode and the modifications induced on the base state by their finite amplitude evolution.

  11. Numerical study of Q-ball formation in gravity mediation

    International Nuclear Information System (INIS)

    Hiramatsu, Takashi; Kawasaki, Masahiro; Takahashi, Fuminobu

    2010-01-01

    We study Q-ball formation in the expanding universe on 1D, 2D and 3D lattice simulations. We obtain detailed Q-ball charge distributions, and find that the distribution is peaked at Q 3D peak ≅ 1.9 × 10 −2 (|Φ in |/m) 2 , which is greater than the existing result by about 60%. Based on the numerical simulations, we discuss how the Q-ball formation proceeds. Also we make a comment on possible deviation of the charge distributions from what was conjectured in the past

  12. Studying hand grip strength development among students who have taken tennis and massage courses

    Directory of Open Access Journals (Sweden)

    Erzeybek Mustafa Said

    2017-01-01

    Full Text Available In this study, the finger and hand force developments of the students who have taken selective/applied Tennis and Massage courses at the University have been examined. From the students of the Department of Physical Education and Sport, 19 healthy females and 73 healthy males (age = 21.25 ± 1.55 years (average ± SD who have taken selective Tennis courses;51 healthy males (age = 22.00 ± 1.04 years (average ± SD who have taken Massage courses; and as the control group,16 healthy womenand50 healthy males(age = 21.72 ± 1.47 years (average ± SD have been participated to the study. The age, length, body weight, grip strength of both hands as well as the finger grip strength of the subjects have been recorded. The course schedule has been set as once a week four hours practice for both tennis and massage. Two weeks of the education and training program that takes twelve weeks in total were assigned for theoretical classes. The remaining period of ten weeks was for practice classes and the measurements were performed before and after this ten weeks period. The hand grip strength measurement has been carried out with a Takkei branded hand dynamometer whereas for the measurement of the finger grip strength, a Baseline branded pinch meter has been used. For both the pre-test and final test of the finger grip and hand grip strength measurements, the paired sample t test has been used in terms of in-group comparisons, whereas for the inter-group comparisons, one-way ANOVA has been used. For the significant F values, post hoc Tukey test has been used. The right hand and the left hand grip values of both test groups as well as the values of the control group have been significantly increased between the pre-test and final test. Particularly, preferring the exercises that improve the hand and finger grip strengths would enable a better racket handle grip as well as an improved shot efficiency for tennis. This would also enable masseurs/masseuses to apply

  13. Economic Evaluation of a Multifaceted Implementation Strategy for the Prevention of Hand Eczema Among Healthcare Workers in Comparison with a Control Group: The Hands4U Study.

    NARCIS (Netherlands)

    Van Der Meer, Esther W C; van Dongen, J.M.; Boot, C.R.; van der Gulden, J.W.; Bosmans, J.E.; Anema, J.R.

    2016-01-01

    The aim of this study was to evaluate the cost-effectiveness of a multifaceted implementation strategy for the prevention of hand eczema in comparison with a control group among healthcare workers. A total of 48 departments (n=1,649) were randomly allocated to the implementation strategy or the

  14. Economic Evaluation of a Multifaceted Implementation Strategy for the Prevention of Hand Eczema Among Healthcare Workers in Comparison with a Control Group: The Hands4U Study

    NARCIS (Netherlands)

    Meer, E.W. van der; Dongen, J.M. van; Boot, C.R.; Gulden, J.W.J. van der; Bosmans, J.E.; Anema, J.R.

    2016-01-01

    The aim of this study was to evaluate the cost-effectiveness of a multifaceted implementation strategy for the prevention of hand eczema in comparison with a control group among healthcare workers. A total of 48 departments (n=1,649) were randomly allocated to the implementation strategy or the

  15. Numerical study of gravity currents in a channel

    International Nuclear Information System (INIS)

    Wang, D.

    1985-01-01

    A three-dimensional, primitive-equation model was used to study gravity currents produced by instantaneous releases of a buoyant fluid in a rectangular channel. Without rotation, the gravity current passes through two distinct phases: an initial adjustment phase in which the front speed is constant, and an eventual self-similar phase in which the front speed decreases with time. With rotation, the gravity current is confined to the right-hand wall, forming a coastal jet. The initial front-speed is constant; however, the front speed decreases rapidly due to strong mixing at the horizontal edge of the gravity current. Also, with rotation, part of the buoyant fluid is trapped near the source region, forming an anticyclonic vortex

  16. Stapled versus hand-sewn cervical esophagogastric anastomosis in patients undergoing esophagectomy: A Retrospective Cohort Study

    Science.gov (United States)

    Mishra, Pramod Kumar; Shah, Harsh; Gupta, Nikhil; Varshney, Vaibhav; Patil, Nilesh Sadashiv; Jain, Amit; Saluja, Sundeep Singh

    2016-01-01

    Introduction Anastomotic leak is one of the main causes of morbidity following esophageal resection for carcinoma of the esophagus and gastroesophageal junction. We compared hand sewn and stapled cervical esophagogastric anastomotic techniques in terms of postoperative complications. Methods All patients who underwent esophagectomy with cervical esophagogastric anastomosis at a single academic center from 2004 to 2014 were included in the study. Both early and late complications were analyzed. Results 153 patients underwent resection for carcinoma of the esophagus and gastroesophageal junction. Of these 140 patients had esophagectomy with cervical esophagogastric anastomosis. 66 patients underwent a hand sewn anastomosis and 74 patients had a side-to-side stapled anastomosis fashioned. Both groups were comparable with respect to preoperative characteristics. There was no difference in the operative blood loss and T and N stage of the disease. The overall morbidity and mortality was 32.8% and 6.4%, respectively. Overall leak rate was 17%. There was no difference in the leak rates among two groups (12 in the hand-sewn group & 12 in the Stapled stapled group; p = 0.82). The rate of anastomotic stricture was significantly higher for the hand sewn group (16.1% vs 4.3%; p = 0.03) at median follow up of 30 months. Conclusion Both hand sewn and stapled anastomotic techniques are equally effective way of performing a cervical esophagogastric anastomosis. However, patients having anastomotic leak develop anastomotic stricture more often in those having hand-sewn anastomosis compared to stapled anastomosis. PMID:27222711

  17. Study and simulation of a parallel numerical processing machine

    International Nuclear Information System (INIS)

    Bel Hadj, Slaheddine

    1981-12-01

    This study has been carried out in the perspective of the implementation on a minicomputer of the NEPTUNIX package (software for the resolution of very large algebra-differential equation systems). Aiming at increasing the system performance, a previous research work has shown the necessity of reducing the execution time of certain numerical computation tasks, which are of frequent use. It has also demonstrated the feasibility of handling these tasks with efficient algorithms of parallel type. The present work deals with the study and simulation of a parallel architecture processor adapted to the fast execution of these algorithms. A minicomputer fitted with a connection to such a parallel processor, has a greatly extended computing power. Then the architecture of a parallel numerical processor, based on the use of VLSI microprocessors and co-processors, is described. Its design aims at the best cost / performance ratio. The last part deals with the simulation processor with the 'CHAMBOR' program. Results show an increasing factor of 30 in speed, in comparison with the execution on a MITRA 15 minicomputer. Moreover the conflicts importance, mainly at the level of access to a shared resource is evaluated. Although this implementation has been designed having in mind a dedicated application, other uses could be envisaged, particularly for the simulation of nuclear reactors: operator guiding system, the behavioural study under accidental circumstances, etc. (author) [fr

  18. Hydroxychloroquine effectiveness in reducing symptoms of hand osteoarthritis (HERO): study protocol for a randomized controlled trial

    Science.gov (United States)

    2013-01-01

    Background Osteoarthritis (OA) is the most common type of arthritis, causing significant joint pain and disability. It is already a major cause of healthcare expenditure and its incidence will further increase with the ageing population. Current treatments for OA have major limitations and new analgesic treatments are needed. Synovitis is prevalent in OA and is associated with pain. Hydroxychloroquine is used in routine practice for treating synovitis in inflammatory arthritides, such as rheumatoid arthritis. We propose that treating patients with symptomatic hand OA with hydroxychloroquine will be a practical and safe treatment to reduce synovitis and pain. Methods/design HERO is an investigator-initiated, multicentre, randomized, double-blind, placebo-controlled trial. A total of 252 subjects with symptomatic hand OA will be recruited across primary and secondary care sites in the UK and randomized on a 1:1 basis to active treatment or placebo for 12 months. Daily medication dose will range from 200 to 400 mg according to ideal body weight. The primary endpoint is change in average hand pain during the previous two weeks (measured on a numerical rating scale (NRS)) between baseline and six months. Secondary endpoints include other self-reported pain, function and quality-of-life measures and radiographic structural change at 12 months. A health economics analysis will also be performed. An ultrasound substudy will be conducted to examine baseline levels of synovitis. Linear and logistic regression will be used to compare changes between groups using univariable and multivariable modelling analyses. All analyses will be conducted on an intention-to-treat basis. Discussion The HERO trial is designed to examine whether hydroxychloroquine is an effective analgesic treatment for OA and whether it provides any long-term structural benefit. The ultrasound substudy will address whether baseline synovitis is a predictor of therapeutic response. This will potentially

  19. Analytical and Numerical Studies of Several Fluid Mechanical Problems

    Science.gov (United States)

    Kong, D. L.

    2014-03-01

    In this thesis, three parts, each with several chapters, are respectively devoted to hydrostatic, viscous, and inertial fluids theories and applications. Involved topics include planetary, biological fluid systems, and high performance computing technology. In the hydrostatics part, the classical Maclaurin spheroids theory is generalized, for the first time, to a more realistic multi-layer model, establishing geometries of both the outer surface and the interfaces. For one of its astrophysical applications, the theory explicitly predicts physical shapes of surface and core-mantle-boundary for layered terrestrial planets, which enables the studies of some gravity problems, and the direct numerical simulations of dynamo flows in rotating planetary cores. As another application of the figure theory, the zonal flow in the deep atmosphere of Jupiter is investigated for a better understanding of the Jovian gravity field. An upper bound of gravity field distortions, especially in higher-order zonal gravitational coefficients, induced by deep zonal winds is estimated firstly. The oblate spheroidal shape of an undistorted Jupiter resulting from its fast solid body rotation is fully taken into account, which marks the most significant improvement from previous approximation based Jovian wind theories. High viscosity flows, for example Stokes flows, occur in a lot of processes involving low-speed motions in fluids. Microorganism swimming is such a typical case. A fully three dimensional analytic solution of incompressible Stokes equation is derived in the exterior domain of an arbitrarily translating and rotating prolate spheroid, which models a large family of microorganisms such as cocci bacteria. The solution is then applied to the magnetotactic bacteria swimming problem, and good consistency has been found between theoretical predictions and laboratory observations of the moving patterns of such bacteria under magnetic fields. In the analysis of dynamics of planetary

  20. An Experimental and numerical Study for squeezing flow

    Science.gov (United States)

    Nathan, Rungun; Lang, Ji; Wu, Qianhong; Vucbmss Team

    2017-11-01

    We report an experimental and numerical study to examine the transient squeezing flow driven by sudden external impacts. The phenomenon is widely observed in industrial applications, e.g. squeeze dampers, or in biological systems, i.e. joints lubrication. However, there is a lack of investigation that captures the transient flow feature during the process. An experimental setup was developed that contains a piston instrumented with a laser displacement sensor and a pressure transducer. The heavy piston was released from rest, creating a fast compaction on the thin fluid gap underneath. The motion of the piston and the fluid pressure build-up was recorded. For this dynamic process, a CFD simulation was performed which shows excellent agreement with the experimental data. Both the numerical and experimental results show that, the squeezing flow starts with the inviscid limit when the viscous fluid effect has no time to appear, and thereafter becomes a developing flow, in which the inviscid core flow region decreases and the viscous wall region increases until the entire fluid gap is filled with viscous fluid flow. The study presented herein, filling the gap in the literature, will have broad impacts in industrial and biomedical applications. This research was supported by the National Science Foundation under Award 1511096, and supported by the Seed Grant from The Villanova Center for the Advancement of Sustainability in Engineering (VCASE).

  1. Experimental and numerical studies of rotating drum grate furnace

    Directory of Open Access Journals (Sweden)

    Basista Grzegorz

    2017-01-01

    Full Text Available Waste material from the meat industry can be taken into account as a biofuel. Studies confirm, that calorific value is higher and ash content is lower comparing to some conventional fuels. EU directives regulate details of thermal disposal of the waste material from the meat industry - especially in range of the process temperature and time of the particle presence in area of the combustion zone. The paper describes design of the rotating drum grate stove, dedicated to thermal disposal of the meat wastes as well as solid biomass (pellet, small bricket, wood chips combustion. Device has been developed in frames of cooperation between AGH University of Science and Technology (Krakow, Poland and producer focused on technologies of energy utilization of biomass in distributed generation. Results of measurements of selected operational parameters performed during startup of the furnace have been presented and discussed. Furthermore, numerical model of the combustion process has been developed to complement experimental results in range of the temperature and oxygen distribution in the area of the combustion chamber. ANSYS CFX solver has been applied to perform simulations including rotational domain related with specifics of operation of the device. Results of numerical modelling and experimental studies have been summarized and compared.

  2. Numerical study of droplet evaporation in an acoustic levitator

    Science.gov (United States)

    Bänsch, Eberhard; Götz, Michael

    2018-03-01

    We present a finite element method for the simulation of all relevant processes of the evaporation of a liquid droplet suspended in an acoustic levitation device. The mathematical model and the numerical implementation take into account heat and mass transfer across the interface between the liquid and gaseous phase and the influence of acoustic streaming on this process, as well as the displacement and deformation of the droplet due to acoustic radiation pressure. We apply this numerical method to several theoretical and experimental examples and compare our results with the well-known d2-law for the evaporation of spherical droplets and with theoretical predictions for the acoustic streaming velocity. We study the influence of acoustic streaming on the distribution of water vapor and temperature in the levitation device, with special attention to the vapor distribution in the emerging toroidal vortices. We also compare the evaporation rate of a droplet with and without acoustic streaming, as well as the evaporation rates in dependence of different temperatures and sound pressure levels. Finally, a simple model of protein inactivation due to heat damage is considered and studied for different evaporation settings and their respective influence on protein damage.

  3. A numerical study of a supercritical fluid jet

    International Nuclear Information System (INIS)

    Sierra-Pallares, J.; Garcia-Serna, J.; Cocero, M.J.; Parra-Santos, M.T.; Castro-Ruiz, F.

    2009-01-01

    This study affords the numerical solution of the mixing of a submerged turbulent jet under supercritical conditions and near-critical conditions. Turbulence plays a very important role in the behaviour of chemical engineering equipment. An accurate prediction of the turbulence at supercritical conditions with low computational cost is crucial in designing new processes such as reactions in supercritical media, high pressure separation processes, nanomaterials processing and heterogeneous catalysis. At high-pressure, the flow cannot be modelled accurately using the ideal-gas assumption. Therefore, the real gas models must be used in order to solve accurately the fluid flow and heat transfer problems where the working fluid behaviour deviate seriously from the ideal-gas assumption. The jet structure has three parts clearly distinguished: the injection, the transition and the fully developed jet. Once the flow is dominated by the turbulent eddies of the shear layer, the flow is fully developed and the radial profiles match a similarity profile. This work reports the state of the project that is not completed and is being processed now. This work is devoted to establish the distance downstream from the injector where the jet become self-preserving and the shape of the similarity profiles. This system is of interest in the design of supercritical reactor inlets, where two streams should be mixed in the shortest length, or mixing conditions strongly affect the behaviour of the processes. The numerical results have been validated with experimental measurements made in the jet mixing region. The radial profiles for average velocity, density and temperature are analyzed. The parameters of the profile that match better the numerical results are summarized in Table 1. The density requires a lower value of n than these for velocity and temperature, which reflect smoother profiles. These conclusions are in good agreement with the results from Oschwald and Schik. (author)

  4. Numerical study on aerodynamics of banked wing in ground effect

    Directory of Open Access Journals (Sweden)

    Qing Jia

    2016-03-01

    Full Text Available Unlike conventional airplane, a WIG craft experiences righting moment and adverse yaw moment in banked turning in ground effect. Numerical simulations are carried out to study the aerodynamics of banked wing in ground effect. Configurations of rectangular wing and delta wing are considered, and performance of endplates and ailerons during banking are also studied. The study shows that righting moment increase nonlinearly with heeling angle, and endplates enhance the righting. The asymmetric aerodynamic distribution along span of wing with heeling angle introduces adverse yaw moment. Heeling in ground effect with small ground clearance increases the vertical aerodynamic force and makes WIG craft climb. Deflections of ailerons introduce lift decrease and a light pitching motion. Delta wing shows advantage in banked turning for smaller righting moment and adverse yaw moment during banking.

  5. Stiff Hands

    Science.gov (United States)

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

  6. Hand Infections

    Science.gov (United States)

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

  7. A Study of Memory and Forgetting in The Sound of One Hand Clapping

    Institute of Scientific and Technical Information of China (English)

    杨炤宇

    2011-01-01

    The Sound of One Hand Clapping is a 1997 novel by Australian author Richard Flanagan. Richard Flanagan was born in 1961 in Tasmania. He left school at 16, later winning a Rhodes scholarship to Oxford, where he took a Master of Letters degree. He later worked as a labourer and river guide. The Sound of One Hand Clapping (1998) is his second novel which tells the story of Slovenian immigrants; Richard Flanagan also wrote and directed the film version of The Sound of One Hand Clapping, which was re- leased in 1998, and world premiered at the 1998 Berlin Film Festival, where it was nominated for Golden Bear for Best film. The novel, The Sound of One Hand Clapping (1998), examines the Tasmanian immigrant experience. It asks us not to ignore the existence of the soul and the spirit, not to sublimate all to a blind rationality, Flanagan also suggests that healing is not only possible but that it should be looked for. Original, poetic and compelling, this novel comes highly recommended,?As the novel is formed largely by means of memory and forgetting. So the author of this paper intends to give a tentative study of memory as well as forgetting, Wing to figure out the reasons and influences that memory and forgetting brings on different characters.

  8. Hand fractures: A study of their site and type in childhood

    International Nuclear Information System (INIS)

    Rajesh, Arumugam; Basu, Avi K.; Vaidhyanath, Ramachandran; Finlay, David

    2001-01-01

    AIM: The purpose of the study was to document the site and type of fractures of the hand in children up to 16 years of age. MATERIALS AND METHODS: The radiographs of 280 children who were found to have a fracture in Accident and Emergency over a one-year period were reviewed. A total of 293 fractures of the hand and 3 distal interphalangeal joint dislocations without fracture were identified. There were 293 fractures as some children had more than one fracture. RESULTS: Distal tuft fractures were commonest in the 0 to 4-year age-group; fractures of distal phalanx (both transverse and tuft) in the 5 to 8-year age-group; transverse fractures of the proximal phalanx of little finger in the 9 to 12-year age-group and transverse fractures of neck of the fifth metacarpal in the 13 to 16-year age-groups. CONCLUSION: Hand fractures are more common in older children, with a male preponderance in most groups except in the 0-4 age-group. The site of injury is different in the various corresponding age-groups, reflecting the differing mechanisms of injury. The management of hand fractures rely on a correct diagnosis and a knowledge of their common site in each age-group should aid diagnosis. Rajesh, A. et al. (2001)

  9. Study of External Radiation Expose Dose on Hands of Nuclear Medicine Workers

    International Nuclear Information System (INIS)

    Park, Jun Chul; Pyo, Sung Jae

    2012-01-01

    The aims of this study are to assess external radiation exposed doses of body and hands of nuclear medicine workers who handle radiation sources, and to measure radiation exposed doses of the hands induced by a whole body bone scan with high frequency and handling a radioactive sources like 99m Tc-HDP and 18 F-FDG in the PET/CT examination. Skillful workers, who directly dispense and inject from radiation sources, were asked to wear a TLD on the chest and ring finger. Then, radiation exposed dose and duration exposed from daily radiation sources for each section were measured by using a pocket dosimeter for the accumulated external doses and the absorbed dose to the hands. In the survey of four medical institutions in Incheon Metropolitan City, only one of four institutions has a radiation dosimeter for local area like hands. Most of institutions uses radiation shielding devices for the purpose of protecting the body trunk, not local area. Even some institutions were revealed not to use such a shielding device. The exposed doses on the hands of nuclear medicine workers who directly handles radioactive sources were approximately twice as much as those on the body. The radiation exposure level for each section of the whole body bone scan with high frequency and that of the PET/CT examination showed that radiation doses were revealed in decreasing order of synthesis of radioactive medicine and installation to a dispensing container, dispensing, administering and transferring. Furthermore, there were statistically significant differences of radiation exposure doses of the hands before and after wearing a syringe shielder in administration of a radioactive sources. In this study, although it did not reach the permissible effective dose for nuclear medicine, the occupational workers were exposed by relatively higher dose level than the non-occupational workers. Therefore, the workers, who closely exposed to radioactive sources should be in compliance with safety

  10. Numerical and Experimental Study of Amplitude Modulated Positive Corona Discharge

    Directory of Open Access Journals (Sweden)

    Pablo Martín GOMEZ

    2014-12-01

    Full Text Available The electrical behavior of a modulated positive corona discharge loudspeaker was studied. A coaxial transducer in air was built using a central copper wire of 75 mm radius (inner electrode and a perforated tube of 11 mm (outer electrode. A high voltage DC supply provided the bias current and a sinusoidal signal was superimposed to measure the discharge admittance. The experimental results could not be matched to previously reported equivalent circuits with fixed components. Using the basic equations that describe the ion motion, a numerical model was proposed. The computed values matched well the experimental data and suggested an equivalent circuit composed of frequency dependent conductance and capacitance. This dependence is closely related to the ion travel time between electrodes (transit time. Simulations carried out at several inter-electrode distances could be synthesized in a single plot where the different results overlap and further emphasize the role of the transit time. This numerical model proved to be an efficient tool to simulate and design modulated corona transducers.

  11. Experimental and Numerical Study of Twin Underexpanded Impinging Jets

    Institute of Scientific and Technical Information of China (English)

    Minoru Yaga; Minoru Okano; Masumi Tamashiro; Kenyu Oyakawa

    2003-01-01

    In this paper, the dual underexpanded impinging jets are experimentally and numerically studied. The experiments were performed by measuring the unsteady and averaged wall static pressures and by visualizing density fields using schlieren method. Numerical calculations were also conducted by solving unsteady three dimensional compressible Navier-Stokes equations with Baldwin-Lomax turbulence model. The main parameters for the dual jets are the non-dimensional distance between the two nozzle centers H/D covering 1.5, 2.0, the nozzle to plate separation L/D 2.0, 3.0,4.0 and 5.0 and the pressure ratio defined by Po/Pb 1.0~6.0, where D is the diameter of each nozzle exit, Po the stagnation pressure and Pb the back pressure. It is found that the agreement between the experiments and the calculations is good. The fountain flow at the middle of the two jets is observed both in the experiments and the calculation. According to FFT analysis of the experiments for the twin jets,relatively low frequency (up to 5 kHz) is dominant for H/D =1.5, L/D =2.0 and pressure ratio Po/Pb =3.0 and 5.0,which is confirmed by the experiments.

  12. A numerical study of non-linear crack tip parameters

    Directory of Open Access Journals (Sweden)

    F.V. Antunes

    2015-07-01

    Full Text Available Crack closure concept has been widely used to explain different issues of fatigue crack propagation. However, different authors have questioned the relevance of crack closure and have proposed alternative concepts. The main objective here is to check the effectiveness of crack closure concept by linking the contact of crack flanks with non-linear crack tip parameters. Accordingly, 3D-FE numerical models with and without contact were developed for a wide range of loading scenarios and the crack tip parameters usually linked to fatigue crack growth, namely range of cyclic plastic strain, crack tip opening displacement, size of reversed plastic zone and total plastic dissipation per cycle, were investigated. It was demonstrated that: i LEFM concepts are applicable to the problem under study; ii the crack closure phenomenon has a great influence on crack tip parameters decreasing their values; iii the Keff concept is able to explain the variations of crack tip parameters produced by the contact of crack flanks; iv the analysis of remote compliance is the best numerical parameter to quantify the crack opening level; v without contact there is no effect of stress ratio on crack tip parameters. Therefore it is proved that the crack closure concept is valid.

  13. Theoretical and numerical study of heat transfer deterioration in HPLWR

    International Nuclear Information System (INIS)

    Palko, D.; Anglart, H.

    2007-01-01

    A numerical investigation of the Heat Transfer Deterioration (HTD) phenomena is performed using the low-Re k - ω turbulence model. Steady state Reynolds-averaged Navier-Stokes equations are solved together with equations for the transport of enthalpy and turbulence. Equations are solved for the supercritical water flow at different pressures, using water properties from the standard IAPWS tables. All cases are extensively validated against experimental data. The influence of buoyancy on the HTD is demonstrated for different mass flow rates in the heated pipes. Numerical results prove that the RANS low-Re turbulence modeling approach is fully capable to simulate the heat transfer in pipes with the water flow at supercritical pressures. A study of buoyancy influence shows that for the low mass flow rates of coolant, the influence of buoyancy forces on the heat transfer in heated pipes is significant. For the high flow rates, buoyancy influence could be neglected and there are clearly other mechanisms causing the decrease in heat transfer at high coolant flow rates. (author)

  14. Numerical Boron mixing studies for Loviisa Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Gango, P. [IVO International Ltd. (Finland)

    1995-09-01

    A program has been started for studying numerically boron mixing in the downcomer of Loviisa NPP (VVER-440). Mixing during the transport of a diluted slug from the loop to the core might serve as an inherent protection mechanism against severe reactivity accidents in inhomogenous boron dilution scenarios for PWRs. The commercial general purpose Computational Fluid Dynamics (CFD) core PHOENICS is used for solving the governing fluid flow equations in the downcomer geometry of VVER-440. So far numerical analyses have been performed for steady state operation conditions and two different pump driven transients. The steady state analyses focused on model development and validation against existing experimental data. The two pump driven transient scenarios reported are based on slug transport during the start of the sixth and first loop respectively. The results from the two transients show that mixing is case and plant specific; the high and open downcomer geometry of VVER-440 seems to be advantageous from mixing point of view. In addition the analyzing work for the {open_quotes}first pump start{close_quotes} scenario brought up some considerations about flow distribution in the existing experimental facilities.

  15. Numerical Continuation Methods for Intrusive Uncertainty Quantification Studies

    Energy Technology Data Exchange (ETDEWEB)

    Safta, Cosmin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Najm, Habib N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Phipps, Eric Todd [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Rigorous modeling of engineering systems relies on efficient propagation of uncertainty from input parameters to model outputs. In recent years, there has been substantial development of probabilistic polynomial chaos (PC) Uncertainty Quantification (UQ) methods, enabling studies in expensive computational models. One approach, termed ”intrusive”, involving reformulation of the governing equations, has been found to have superior computational performance compared to non-intrusive sampling-based methods in relevant large-scale problems, particularly in the context of emerging architectures. However, the utility of intrusive methods has been severely limited due to detrimental numerical instabilities associated with strong nonlinear physics. Previous methods for stabilizing these constructions tend to add unacceptably high computational costs, particularly in problems with many uncertain parameters. In order to address these challenges, we propose to adapt and improve numerical continuation methods for the robust time integration of intrusive PC system dynamics. We propose adaptive methods, starting with a small uncertainty for which the model has stable behavior and gradually moving to larger uncertainty where the instabilities are rampant, in a manner that provides a suitable solution.

  16. Numerical and Experimental Study of Mechanisms Involved in Boiling Histotripsy.

    Science.gov (United States)

    Pahk, Ki Joo; Gélat, Pierre; Sinden, David; Dhar, Dipok Kumar; Saffari, Nader

    2017-12-01

    The aim of boiling histotripsy is to mechanically fractionate tissue as an alternative to thermal ablation for therapeutic applications. In general, the shape of a lesion produced by boiling histotripsy is tadpole like, consisting of a head and a tail. Although many studies have demonstrated the efficacy of boiling histotripsy for fractionating solid tumors, the exact mechanisms underpinning this phenomenon are not yet well understood, particularly the interaction of a boiling vapor bubble with incoming incident shockwaves. To investigate the mechanisms involved in boiling histotripsy, a high-speed camera with a passive cavitation detection system was used to observe the dynamics of bubbles produced in optically transparent tissue-mimicking gel phantoms exposed to the field of a 2.0-MHz high-intensity focused ultrasound (HIFU) transducer. We observed that boiling bubbles were generated in a localized heated region and cavitation clouds were subsequently induced ahead of the expanding bubble. This process was repeated with HIFU pulses and eventually resulted in a tadpole-shaped lesion. A simplified numerical model describing the scattering of the incident ultrasound wave by a vapor bubble was developed to help interpret the experimental observations. Together with the numerical results, these observations suggest that the overall size of a lesion induced by boiling histotripsy is dependent on the sizes of (i) the heated region at the HIFU focus and (ii) the backscattered acoustic field by the original vapor bubble. Copyright © 2017 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

  17. Numerical simulation system for environmental studies: SPEEDI-MP

    International Nuclear Information System (INIS)

    Nagai, Haruyasu; Chino, Masamichi; Terada, Hiroaki; Harayama, Takaya; Kobayashi, Takuya; Tsuduki, Katsunori; Kim, Keyong-Ok; Furuno, Akiko

    2006-09-01

    A numerical simulation system SPEEDI-MP has been developed to apply for various environmental studies. SPEEDI-MP consists of dynamical models and material transport models for the atmospheric, terrestrial, and oceanic environments, meteorological and geographical database for model inputs, and system utilities for file management, visualization, analysis, etc., using graphical user interfaces (GUIs). As a numerical simulation tool, a model coupling program (model coupler) has been developed. It controls parallel calculations of several models and data exchanges among them to realize the dynamical coupling of the models. A coupled model system for water circulation has been constructed with atmosphere, ocean, wave, hydrology, and land-surface models using the model coupler. System utility GUIs are based on the Web technology, allowing users to manipulate all the functions on the system using their own PCs via the internet. In this system, the source estimation function in the atmospheric transport model can be executed on the grid computer system. Performance tests of the coupled model system for water circulation were also carried out for the flood event at Saudi Arabia in January 2005 and the storm surge case by the hurricane KATRINA in August 2005. (author)

  18. Numerical study of Taylor bubbles with adaptive unstructured meshes

    Science.gov (United States)

    Xie, Zhihua; Pavlidis, Dimitrios; Percival, James; Pain, Chris; Matar, Omar; Hasan, Abbas; Azzopardi, Barry

    2014-11-01

    The Taylor bubble is a single long bubble which nearly fills the entire cross section of a liquid-filled circular tube. This type of bubble flow regime often occurs in gas-liquid slug flows in many industrial applications, including oil-and-gas production, chemical and nuclear reactors, and heat exchangers. The objective of this study is to investigate the fluid dynamics of Taylor bubbles rising in a vertical pipe filled with oils of extremely high viscosity (mimicking the ``heavy oils'' found in the oil-and-gas industry). A modelling and simulation framework is presented here which can modify and adapt anisotropic unstructured meshes to better represent the underlying physics of bubble rise and reduce the computational effort without sacrificing accuracy. The numerical framework consists of a mixed control-volume and finite-element formulation, a ``volume of fluid''-type method for the interface capturing based on a compressive control volume advection method, and a force-balanced algorithm for the surface tension implementation. Numerical examples of some benchmark tests and the dynamics of Taylor bubbles are presented to show the capability of this method. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  19. Predictors of hand hygiene practice among Saudi nursing students: A cross-sectional self-reported study.

    Science.gov (United States)

    Cruz, Jonas P; Bashtawi, Meshrif A

    2016-01-01

    Hand hygiene is an important component of infection control, which is critical to ensuring patients' safety in hospitals. Nursing students are regarded as healthcare workers in training and can also be vehicles of cross-contamination within the hospital. Thus, this study aimed to identify the predictors of hand hygiene practice among Saudi nursing students. A descriptive, cross-sectional, self-reported study was conducted among 198 Saudi nursing students. Knowledge, attitude, and practice of hand hygiene were assessed using the WHO Hand Hygiene Knowledge Questionnaire for Health-Care Workers and its adopted scales. A regression analysis was performed to identify the predictors of hand hygiene practice. The respondents demonstrated moderate knowledge of hand hygiene (mean 13.20±2.80). The majority displayed a moderate attitude toward hand hygiene (52.1%), while only a few reported a poor attitude (13.1%). Approximately 68.7%, 29.8%, and 1.5% of the respondents reported moderate, good, and poor practice of hand hygiene, respectively. Having a good attitude toward hand hygiene, being male, being aware that hand hygiene is an effective intervention in preventing healthcare-associated infections (HAIs), attendance at hand hygiene trainings and seminars, and being in the lower academic level of nursing education were identified as predictors of better hand hygiene practice. The importance of ensuring a positive attitude toward hand hygiene and improving awareness of hand hygiene is emphasized, as are educational interventions. Educational interventions should be implemented to reinforce knowledge and instill a positive attitude toward hand hygiene. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  20. Numerical Study of Photoacoustic Pressure for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Thomas Grosges

    2016-11-01

    Full Text Available A commonly used therapy for cancer is based on the necrosis of cells induced by heating through the illumination of nanoparticles embedded in cells. Recently, the photoacoustic pressure shock induced by the illumination pulse was proved and this points to another means of cell destruction. The purpose of this study is to propose a model of the photoacoustic pressure in cells. The numerical resolution of the problem requires the accurate computation of the electromagnetism, the temperature and the pressure around the nanostructures embedded in a cell. Here, the problem of the interaction between an electromagnetic excitation and a gold nanoparticle embedded in a cell domain is solved. The variations of the thermal and photoacoustic pressures are studied in order to analyze the pressure shock wave inducing the collapse of the cell’s membrane in cancer therapy.

  1. A mechatronics platform to study prosthetic hand control using EMG signals.

    Science.gov (United States)

    Geethanjali, P

    2016-09-01

    . This prototype facilitated the study of various issues of pattern recognition and identified an efficient classifier, along with a feature ensemble, in the implementation of EMG controlled prosthetic hands in a laboratory setting at low-cost. This platform may help to motivate and facilitate prosthetic hand research in developing countries.

  2. Hand Osteoblastoma

    Directory of Open Access Journals (Sweden)

    M. Farzan

    2006-06-01

    Full Text Available Background and Aim: Osteoblastoma is one of the rarest primary bone tumors. Although, small bones of the hands and feet are the third most common location for this tumor, the hand involvement is very rare and few case observations were published in the English-language literature. Materials and Methods: In this study, we report five cases of benign osteoblastoma of the hand, 3 in metacarpals and two in phalanxes. The clinical feature is not specific. The severe nocturnal, salicylate-responsive pain is not present in patients with osteoblastoma. The pain is dull, persistent and less localized. The clinical course is usually long and there is often symptoms for months before medical attention are sought. Swelling is a more persistent finding in osteoblastoma of the hand that we found in all of our patients. The radiologic findings are indistinctive, so preoperative diagnosis based on X-ray appearance is difficult. In all of our 5 cases, we fail to consider osteoblastoma as primary diagnosis. Pathologically, osteoblastoma consisting of a well-vascularized connective tissue stroma in which there is active production of osteoid and primitive woven bone. Treatment depends on the stage and localization of the tumor. Curettage and bone grafting is sufficient in stage 1 or stage 2, but in stage 3 wide resection is necessary for prevention of recurrence. Osteosarcoma is the most important differential diagnosis that may lead to inappropriate operation.

  3. Asymptotic and numerical studies of a differential-delay system

    Science.gov (United States)

    Semak, Matthew Richard

    A singularly-perturbed differential-delay equation is studied the form of which is seen in various fields. Relaxation effects are combined with nonlinear driving from the past in this system. Having an infinite dimensional phase space, this flow is capable of very interesting behavior. Among the rich aspects of the dynamics of such a relation, period doubling can be observed as parameters are varied. Rigorous proofs concerning the existence of such periodic solutions can be found in the literature. Attention is given to the (first) Hopf bifurcation as the periodic structure is born. Key questions concern the limit of fast relaxation. In this limit, one can analytically understand the development of the periodic solution in the neighborhood of the bifurcation along with the frequency shift which is encountered. This limit also reveals the underlying mapping structure present. In the model studied, this is the logistic map the behavior of which is well-known. Convergence of periodic solutions to the mapping's square wave involves central issues in this work. An analogue to Gibb's phenomenon presents itself as the mapping structure is approached for a certain range of parameters. Transition layers also exist and, together with the latter, present a challenge to various computational approaches. A highly accurate and efficient spectral numerical technique is introduced to properly resolve such behavior in the limit studied. This scheme is used to measure the period's dependence on the relaxation rate in this region of parameter space. Also, numerically assisted asymptotic analysis develops relations for the layers. Moreover, regimes of parameter values have been identified for which there exist extremely long-lived transient states of arbitrarily complex form. Finally, initial interval states are designed which lead to specific long-lived multi-layer patterns of significant complexity. Layer-layer interactions are considered concerning the formation and lifetime of

  4. Using environmental engineering to increase hand hygiene compliance: a cross-over study protocol.

    Science.gov (United States)

    Schmidtke, Kelly Ann; Aujla, Navneet; Marshall, Tom; Hussain, Abid; Hodgkinson, Gerard P; Arheart, Kristopher; Marti, Joachim; Birnbach, David J; Vlaev, Ivo

    2017-09-11

    Compliance with hand hygiene recommendations in hospital is typically less than 50%. Such low compliance inevitably contributes to hospital-acquired infections that negatively affect patients' well-being and hospitals' finances. The design of the present study is predicated on the assumption that most people who fail to clean their hands are not doing so intentionally, they just forget. The present study will test whether psychological priming can be used to increase the number of people who clean their hands on entering a ward. Here, we present the protocol for this study. The study will use a randomised cross-over design. During the study, each of four wards will be observed during four conditions: olfactory prime, visual prime, both primes and neither prime. Each condition will be experienced for 42 days followed by a 7-day washout period (total duration of trial=189 days). We will record the number of people who enter each ward and whether they clean their hands during observation sessions, the amount of cleaning material used from the dispensers each week and the number of hospital-acquired infections that occur in each period. The outcomes will be compared using a regression analysis. Following the initial trail, the most effective priming condition will be rolled out for 3 months in all the wards. Research ethics approval was obtained from the South Central-Oxford C Research Ethics Committee (16/SC/0554), the Health Regulatory Authority and the sponsor. ISRCTN (15397624); Edge ID 86357. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Differential involvement of cortical and cerebellar areas using dominant and nondominant hands: An FMRI study

    Science.gov (United States)

    Pardini, Matteo; Samson, Rebecca S.; D'Angelo, Egidio; Friston, Karl J.; Toosy, Ahmed T.; Gandini Wheeler‐Kingshott, Claudia A.M.

    2015-01-01

    Abstract Motor fMRI studies, comparing dominant (DH) and nondominant (NDH) hand activations have reported mixed findings, especially for the extent of ipsilateral (IL) activations and their relationship with task complexity. To date, no study has directly compared DH and NDH activations using an event‐related visually guided dynamic power‐grip paradigm with parametric (three) forces (GF) in healthy right‐handed subjects. We implemented a hierarchical statistical approach aimed to: (i) identify the main effect networks engaged when using either hand; (ii) characterise DH/NDH responses at different GFs; (iii) assess contralateral (CL)/IL‐specific and hemisphere‐specific activations. Beyond confirming previously reported results, this study demonstrated that increasing GF has an effect on motor response that is contextualised also by the use of DH or NDH. Linear analysis revealed increased activations in sensorimotor areas, with additional increased recruitments of subcortical and cerebellar areas when using the NDH. When looking at CL/IL‐specific activations, CL sensorimotor areas and IL cerebellum were activated with both hands. When performing the task with the NDH, several areas were also recruited including the CL cerebellum. Finally, there were hand‐side‐independent activations of nonmotor‐specific areas in the right and left hemispheres, with the right hemisphere being involved more extensively in sensori‐motor integration through associative areas while the left hemisphere showing greater activation at higher GF. This study shows that the functional networks subtending DH/NDH power‐grip visuomotor functions are qualitatively and quantitatively distinct and this should be taken into consideration when performing fMRI studies, particularly when planning interventions in patients with specific impairments. Hum Brain Mapp 36:5079–5100, 2015. © 2015 Wiley Periodicals, Inc. PMID:26415818

  6. A hard tissue cephalometric comparative study between hand tracing and computerized tracing

    Directory of Open Access Journals (Sweden)

    Ramachandra Prabhakar

    2014-01-01

    Full Text Available Aims: To analyze and compare the angular and linear hard tissue cephalometric measurements using hand-tracing and computerized tracings with Nemoceph and Dolphin software systems. Subjects and Methods: A total of 30 cephalograms were randomly chosen for study with the following criteria, cephalograms of patients with good contrast, no distortion, and minimal radiographic artifacts were considered using the digital method (Kodak 8000 C with 12 angular and nine linear parameters selected for the study. Comparisons were determined by post-hoc test using Tukey HSD method. The N-Par tests were performed using Kruskal-Walli′s method. Statistical Analysis Used: ANOVA and post-hoc. Results: The results of this study show that there is no significant difference in the angular and linear measurements recorded. The P values were significant at 0.05 levels for two parameters, Co-A and Co-Gn with the hand-tracing method. This was significant in ANOVA and post-hoc test by Tukey HSD method. Conclusions: This study of comparison provides support for transition from digital hand to computerized tracing methodology. In fact, digital computerized tracings were easier and less time consuming, with the same reliability irrespective of each method of tracing.

  7. Numerical and Experimental Study of Friction Loss in Hydrostatic Motor

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Mørk; Hansen, Michael R.; Mouritsen, Ole Ø.

    2012-01-01

    This paper presents a numerical and experimental study of the losses in a hydrostatic motor principle. The motor is designed so that the structural de ections and lubricating regimes between moving surfaces and, subsequently, the leakage and friction losses, can be controlled during operation....... This is done by means of additional pressure volumes that in uence the stator de ection. These pressures are referred to as compensation pressures and the main emphasis is on friction or torque loss modeling of the motor as a function of the compensation pressures and the high and low pressures related...... to the load torque. The torque loss modeling is identied as a Stribeck curve which depends on gap height. The asperity friction is decreasing exponentially with an increase in gap height. The parameters of the torque loss model are based on prototype measurements that include the structural de ections...

  8. Numerical study of non-ideal Vlasov-BGK plasmas

    International Nuclear Information System (INIS)

    Levchenko, V.D.; Sigov, Y.S.; Premuda, F.

    1995-01-01

    A relatively simple quasi-classical description of quantum plasmas using as first approximation the Bhatnagar-Gross-Krook (BGK) collision integral, if combined with the modern numerical simulation methods, might be effective tool of a deep study of non-ideal plasma kinetics in a variety of urgent applications as inertial confinement and cold fusion, transport and collective properties of highly condensed plasmas in liquid metals, semi- and superconductors and others. Consider one-dimensional degenerate plasma consisting of thermal electrons and thermal bosons (deuterons) in the vicinity of the equilibrium Fermi- and Bose-type distributions respectively. In the frame of our rough mixed model we solve Vlasov-BGK-Poisson eqs using simplified version of the SUR code

  9. Numerical study of impact erosion of multiple solid particle

    Science.gov (United States)

    Zheng, Chao; Liu, Yonghong; Chen, Cheng; Qin, Jie; Ji, Renjie; Cai, Baoping

    2017-11-01

    Material erosion caused by continuous particle impingement during hydraulic fracturing results in significant economic loss and increased production risks. The erosion process is complex and has not been clearly explained through physical experiments. To address this problem, a multiple particle model in a 3D configuration was proposed to investigate the dynamic erosion process. This approach can significantly reduce experiment costs. The numerical model considered material damping and elastic-plastic material behavior of target material. The effects of impact parameters on erosion characteristics, such as plastic deformation, contact time, and energy loss rate, were investigated. Based on comprehensive studies, the dynamic erosion mechanism and geometry evolution of eroded crater was obtained. These findings can provide a detailed erosion process of target material and insights into the material erosion caused by multiple particle impingement.

  10. NATO Advanced Study Institute on Advanced Physical Oceanographic Numerical Modelling

    CERN Document Server

    1986-01-01

    This book is a direct result of the NATO Advanced Study Institute held in Banyuls-sur-mer, France, June 1985. The Institute had the same title as this book. It was held at Laboratoire Arago. Eighty lecturers and students from almost all NATO countries attended. The purpose was to review the state of the art of physical oceanographic numerical modelling including the parameterization of physical processes. This book represents a cross-section of the lectures presented at the ASI. It covers elementary mathematical aspects through large scale practical aspects of ocean circulation calculations. It does not encompass every facet of the science of oceanographic modelling. We have, however, captured most of the essence of mesoscale and large-scale ocean modelling for blue water and shallow seas. There have been considerable advances in modelling coastal circulation which are not included. The methods section does not include important material on phase and group velocity errors, selection of grid structures, advanc...

  11. Numerical Study of Shock-Cylinder Banks Interactions

    International Nuclear Information System (INIS)

    Wang, S.P.; Anderson, M.H.; Oakley, J.G.; Bonazza, R.

    2003-01-01

    A numerical parametric study of shock-cylinder banks interactions is presented using a high resolution Euler solver. Staggered cylinder banks of five rows are chosen with the purpose of modeling IFE reactor cooling tube banks. The effect of the aspect ratio of the intercylinder pitch to the distance between successive cylinder rows on the vertical pressure forces acting on the cylinders with different geometries is investigated. Preliminary results show that the largest vertical force develops on the cylinders of the second or third row. This peak pressure force increases with decreasing values of the aspect ratio. It is shown that an increasing second force peak also appears on the successive rows, starting with the second one, with decreasing aspect ratio. It is also observed that the force on the last-row cylinders basically decreases to the level of that on the first row. The results are useful for the optimal design of the cooling tubes system of IFE reactors

  12. Numerical study of the axisymmetric ideal MHD stability of Extrap

    International Nuclear Information System (INIS)

    Benda, M.

    1993-04-01

    A numerical study of the free-boundary axisymmetric (n=0) ideal magnetohydrodynamical (MHD) motions of the Extrap device is presented. The dependence of stability on current profiles in the plasma and currents in the external conductors is investigated. Results are shown for linear growth-rates and nonlinear saturation amplitudes and their dependence on plasma radius as well as on the conducting shell radius. A method combined of two different algorithms has been developed and tested. The interior region of the plasma is simulated by means of a Lagrangian Finite Element Method (FEM) for ideal magnetohydrodynamics, The method is based on a nonlinear radiation principle for the Lagrangian description of ideal MHD. The Boundary Element Method (BEM) is used together with the Lagrangian FEM to simulate nonlinear motion of an ideal MHD plasma behaviour in a vacuum region under the influence of external magnetic fields. 31 refs

  13. Numerical study of drop spreading on a flat surface

    Science.gov (United States)

    Wang, Sheng; Desjardins, Olivier

    2017-11-01

    In this talk, we perform a numerical study of a droplet on a flat surface with special emphasis on capturing the spreading dynamics. The computational methodology employed is tailored for simulating large-scale two-phase flows within complex geometries. It combines a conservative level-set method to capture the liquid-gas interface, a conservative immersed boundary method to represent the solid-fluid interface, and a sub-grid curvature model at the triple-point to implicitly impose the contact angle of the liquid-gas interface. The performance of the approach is assessed in the inertial droplet spreading regime, the viscous spreading regime of high viscosity drops, and with the capillary oscillation of low viscosity droplets.

  14. NUMERICAL STUDY ON COOLING EFFECT POTENTIAL FROM VAPORIZER DEVICE OF LPG VEHICLE

    Directory of Open Access Journals (Sweden)

    MUJI SETIYO

    2017-07-01

    Full Text Available Over fuel consumption and increased exhaust gas due to the A/C system have become a serious problem. On the other hand, the LPG-fueled vehicle provides potential cooling from LPG phase changes in the vaporizer. Therefore, this article presents the potential cooling effect calculation from 1998 cm3 spark ignition (SI engine. A numerical study is used to calculate the potential heat absorption of latent and sensible heat transfer during LPG is expanded in the vaporizer. Various LPG compositions are also simulated through the engine speed range from 1000 to 6000 rpm. The result shows that the 1998 cm3 engine capable of generating the potential cooling effect of about 1.0 kW at 1000 rpm and a maximum of up to 1.8 kW at 5600 rpm. The potential cooling effects from the LPG vaporizer contributes about 26% to the A/C system works on eco-driving condition.

  15. Numerical study of IP3-induced Ca2+ spiral pattern evolution

    International Nuclear Information System (INIS)

    Tang Jun; Ma Jun; Yi Ming; Jia Ya

    2008-01-01

    The effect of change in concentration of messenger molecule inositol 1,4,5-trisphosphate (IP 3 ) on intracellular Ca 2+ spiral pattern evolution is studied numerically. The results indicate that when the IP 3 concentration decreases from 0.27 μM, a physiologically reasonable value, to different values, the spiral centre drifts to the edge of the medium and disappears for a small enough IP 3 concentration. The instability of spiral pattern can be understood in terms of excitability-change controlled by the IP 3 concentration. On the other hand, when the IP 3 concentration increases from 0.27 μM, a homogeneous area with a high Ca 2+ concentration emerges and competes with the spiral pattern. A high enough IP 3 concentration can lead the homogeneous area to occupy the whole medium. The instability of spiral pattern is ascribed to the change in stability of a stationary state with a high Ca 2+ concentration. (general)

  16. Numerical Study on Heat Transfer Performance of PCHE With Supercritical CO2 as Working Fluid

    International Nuclear Information System (INIS)

    Jeon, Sang Woo; Ngo, Ich-long; Byon, Chan

    2016-01-01

    The printed circuit heat exchanger (PCHE) is regarded as a promising candidate for advanced heat exchangers for the next-generation supercritical CO 2 power generation owing to its high compactness and rigid structure. In this study, an innovative type of PCHE, in which the channel sizes for the heat source fluid and heat sink fluid are different, is considered for analysis. The thermal performance of the PCHE, with supercritical CO 2 as the working fluid, is numerically analyzed. The results have shown that the thermal performance of the PCHE decreases monotonically when the channel size of either the heat source channel or the heat sink channel, because of the decreased flow velocity. On the other hand, the thermal performance of the PCHE is found to be almost independent of the spacing between the channels. In addition, it was found that the channel cross sectional shape has little effect on the thermal performance when the hydraulic diameter of the channel remains constant.

  17. Numerical studies for the analysis of damage caused by gas explosions

    International Nuclear Information System (INIS)

    Rischbieter, F.; Horneff, W.; Michelmann, K.; Schaepermeier, E.

    1981-08-01

    Within the framework of the establishment of an immediate safety programme for the Nuclear Process Heat Project, analyses and data available from former explosion accidents are to be reviewed for the derivation of information to be included in the safety concept for the nuclear process heat system. This system is characterised by a close linkage, both in terms of function and spatial arrangement, of the explosive process unit and the nuclear unit of the process heat system. The study in hand deals with the numerical investigation of the deflagrational damage analysis. It is arranged into two parts: (1) Analysis of selected aspects of the explosion accident at Flixborough by means of comparative assessment of various scenarios. (2) Computer-aided calculation of the characteristics of damage to window panes as one of very common structural elements of accident analyses. (orig./DG) [de

  18. Modeling and numerical study of two phase flow

    International Nuclear Information System (INIS)

    Champmartin, A.

    2011-01-01

    This thesis describes the modelization and the simulation of two-phase systems composed of droplets moving in a gas. The two phases interact with each other and the type of model to consider directly depends on the type of simulations targeted. In the first part, the two phases are considered as fluid and are described using a mixture model with a drift relation (to be able to follow the relative velocity between the two phases and take into account two velocities), the two-phase flows are assumed at the equilibrium in temperature and pressure. This part of the manuscript consists of the derivation of the equations, writing a numerical scheme associated with this set of equations, a study of this scheme and simulations. A mathematical study of this model (hyperbolicity in a simplified framework, linear stability analysis of the system around a steady state) was conducted in a frame where the gas is assumed baro-tropic. The second part is devoted to the modelization of the effect of inelastic collisions on the particles when the time of the simulation is shorter and the droplets can no longer be seen as a fluid. We introduce a model of inelastic collisions for droplets in a spray, leading to a specific Boltzmann kernel. Then, we build caricatures of this kernel of BGK type, in which the behavior of the first moments of the solution of the Boltzmann equation (that is mass, momentum, directional temperatures, variance of the internal energy) are mimicked. The quality of these caricatures is tested numerically at the end. (author) [fr

  19. Surgical exploration of hand wounds in the emergency room: Preliminary study of 80 personal injury claims.

    Science.gov (United States)

    Mouton, J; Houdre, H; Beccari, R; Tarissi, N; Autran, M; Auquit-Auckbur, I

    2016-12-01

    The SHAM Insurance Company in Lyon, France, estimated that inadequate hand wound exploration in the emergency room (ER) accounted for 10% of all ER-related personal injury claims in 2013. The objective of this study was to conduct a critical analysis of 80 claims that were related to hand wound management in the ER and led to compensation by SHAM. Eighty claims filed between 2007 and 2010 were anonymised then included into the study. To be eligible, claims had to be filed with SHAM, related to the ER management of a hand wound in an adult, and closed at the time of the study. Claims related to surgery were excluded. For each claim, we recorded 104 items (e.g., epidemiology, treatments offered, and impact on social and occupational activities) and analysed. Of the 70 patients, 60% were manual workers. The advice of a surgeon was sought in 16% of cases. The most common wound sites were the thumb (33%) and index finger (17%). Among the missed lesions, most involved tendons (74%) or nerves (29%). Many patients had more than one reason for filing a claim. The main reasons were inadequate wound exploration (97%), stiffness (49%), and dysaesthesia (41%). One third of patients were unable to return to their previous job. Mean sick-leave duration was 148 days and mean time from discharge to best outcome was 4.19%. Most claims (79%) were settled directly with the insurance company, 16% after involvement of a public mediator, and 12% in court. The mean compensatory damages award was 4595Euros. Inadequate surgical exploration of hand wounds is common in the ER, carries a risk of lasting and sometimes severe residual impairment, and generates considerable societal costs. IV. Copyright © 2016. Published by Elsevier Masson SAS.

  20. A numerical study for global atmospheric transport-chemistry problems

    NARCIS (Netherlands)

    E.J. Spee (Edwin); J.G. Verwer (Jan); P.M. de Zeeuw (Paul); J.G. Blom (Joke); W. Hundsdorfer (Willem)

    1998-01-01

    htmlabstractAtmospheric air quality modeling relies in part on numerical simulation. Required numerical simulations are often hampered by lack of computer capacity and computational speed. This problem is most severe in the field of global modeling where transport and exchange of trace constituents

  1. A numerical study for global atmospheric transport-chemistry problems

    NARCIS (Netherlands)

    E.J. Spee (Edwin); J.G. Verwer (Jan); P.M. de Zeeuw (Paul); J.G. Blom (Joke); W. Hundsdorfer (Willem)

    1997-01-01

    textabstractAtmospheric air quality modeling relies in part on numerical simulation. Required numerical simulations are often hampered by lack of computer capacity and computational speed. This problem is most severe in the field of global modeling where transport and exchange of trace constituents

  2. A historical overview of nuclear structure studies in Strasbourg Laboratories: instrumentation, measurements and theory modelling—hand-in-hand

    Science.gov (United States)

    Beck, F. A.

    2018-05-01

    This article overviews a long period of an important evolution in the nuclear structure research in Strasbourg Laboratories, focussed on tracking of the weaker and weaker experimental signals carrying the more and more important physics messages. In particular we address the research of signatures of the collective behaviour of the nucleus as suggested in the early works of Bohr, Mottelson and Rainwater—at high and very high angular momenta—as well as the competition between the collective and non-collective excitation modes. These ambitious goals were possible to achieve only by constructing powerful spectrometers and developing related detectors, electronics and data acquisition systems. The theoretical modelling developed in parallel, provided essential guidance when choosing the right experiments and optimising their realisation. Theory calculations were equally helpful in interpreting the results of experiments leading to a more complete understanding of the underlying physics. Moreover, thanks to the development of heavy ion accelerators, the Strasbourg centre was the place where crossed the ways of many experimenters from European countries both from the Western and from the Central part of Europe, the place of the gradual development of more and more sophisticated European gamma-spectrometers in collaboration with more and more laboratories from the increasing number of countries allowing for the frontier-level studies of the nuclear behaviour at very high angular momenta.

  3. Hand-held transendoscopic robotic manipulators: A transurethral laser prostate surgery case study.

    Science.gov (United States)

    Hendrick, Richard J; Mitchell, Christopher R; Herrell, S Duke; Webster, Robert J

    2015-11-01

    Natural orifice endoscopic surgery can enable incisionless approaches, but a major challenge is the lack of small and dexterous instrumentation. Surgical robots have the potential to meet this need yet often disrupt the clinical workflow. Hand-held robots that combine thin manipulators and endoscopes have the potential to address this by integrating seamlessly into the clinical workflow and enhancing dexterity. As a case study illustrating the potential of this approach, we describe a hand-held robotic system that passes two concentric tube manipulators through a 5 mm port in a rigid endoscope for transurethral laser prostate surgery. This system is intended to catalyze the use of a clinically superior, yet rarely attempted, procedure for benign prostatic hyperplasia. This paper describes system design and experiments to evaluate the surgeon's functional workspace and accuracy using the robot. Phantom and cadaver experiments demonstrate successful completion of the target procedure via prostate lobe resection.

  4. Kinetic study of human hand sodium using local in vivo neutron activation analysis

    International Nuclear Information System (INIS)

    Cohen Boulakia, Francine.

    1978-01-01

    Using local 'in vivo' activation analysis, turnover of human hand sodium is studied in 14 subjects, 7 controls and 7 decalcified osteoporotics patients. The hand of each subject is irradiated with neutrons emitted by 52 Cf sources; the equivalent dose delivered is 8 cGy. The 24 Na activity variation is plotted as function of time and the experimental curve so obtained is fitted to two exponentials. Two compartements are identified: a rapidly exchangeable one, with a half life of 1 h; an other, with a very slow turnover, the half lifes varying from 79 h to 35 h as the calcium concentration becomes sub-normal. The ratios calcium to slowly exchangeable sodium and rapidly to slowly exchangeable sodium appear to be promising for the evaluation of bone disease [fr

  5. Automated joint space width quantification of hand and wrist joints: a proof of concept study.

    Science.gov (United States)

    Huo, Yinghe; Veldhuizen, Renske D; van der Heijde, Desiree M; Besselink, Nick J; Jacobs, Johannes W G; van Laar, Jacob M; Viergever, Max A; Vincken, Koen L; Lafeber, Floris P; de Hair, Maria J H

    2016-01-01

    To compare as proof of concept the sensitivity to change of automated quantification of radiographic wrist and hand joint space width (JSW) with scoring JSW according to the Sharp/van der Heijde scoring method (SHS) in two strategy groups of a treat-to-target and tight-control early rheumatoid arthritis (RA) study. Digital radiographs were assessed for JSW changes of 134 patients of the 236 patients participating in the second Computer Assisted Management in Early Rheumatoid Arthritis trial, of whom both baseline and year 2 radiographs were available (year 1 radiographs n=125). Of those 134 patients, 70 started with methotrexate and prednisone (MTX+Pred) and 64 with MTX and placebo (MTX+Plac). JSW change over 1 and 2 years of the hands and wrists was assessed, applying both the joint space narrowing (JSN) subscore of the SHS by 2 readers and the automated assessment with the JSW quantification software 'JSQ'. For both methods, progression of JSW change of the hand and wrist was analysed using linear mixed modelling (dependent variable 'JSW', factor 'strategy group', covariate 'follow-up time in years', interaction term 'strategy group*follow-up time'; radiographs of baseline, year 1 and year 2 were used). For each method the standardised mean difference (SMD) for the change in JSW from baseline to year 2 between the treatment strategies was obtained using a non-parametric method. Patient characteristics of the current subpopulation were similar to those of the whole study population. JSN of the hand and wrist according to SHS at 2 years was present in 16 vs. 23% in the MTX+Pred group vs. the MTX+Plac group. The mean yearly progression rates of JSW change of the hands and wrists using JSQ were -0.00mm (95% confidence interval (CI) -0.01; 0.01) for MTX+Pred vs. -0.02mm (95%CI -0.03; -0.01) for MTX+Plac, p=0.045, and using SHS JSN they were 0.19 units (95%CI 0.09; 0.30) vs. 0.30 units (95%CI 0.14; 0.45) for MTX+Pred vs. MTX+Plac, p=0.271. The SMD for the change from

  6. Numerical Study of Motion of Falling Conical Graupel

    Science.gov (United States)

    Chueh, Chih-Che; Wang, Pao K.; Hashino, Tempei

    2018-01-01

    In the present study, the attitudes of freely-falling conical graupel with a realistic range of densities are investigated numerically by solving the transient Navier-Stokes equations and the body dynamics equations representing the 6-degrees-of-freedom motion. This framework allows us to determine the position and orientation of the graupel in response to the hydrodynamic force of the flow fields. The results show more significant horizontal movements than those cases with a fixed bulk density of ice assumed in our previous study. This is because the real graupel particles possess the density less than the bulk density of ice, which, in turn, leads to a relatively small mass and a relatively small set of moments of inertia. We demonstrate that, with the six degrees of freedom considered together, when Reynolds number is small, a typical damped oscillation occurs, whereas when Reynolds number is high, amplifying oscillation may occur which leads to more complicated and unpredictable flying attitudes such as tumbling. The drag coefficients obtained in the present study agree with the previous studies and can be approximated by that of spheres of the same Reynolds numbers. We also show that conical graupel can perform significant horizontal translations which can be on the order of 1 km in 1 h.

  7. Recent results of seismic isolation study in CRIEPI: Numerical activities

    International Nuclear Information System (INIS)

    Shiojiri, Hiroo; Ishida, Katsuhiko; Yabana, Shurichi; Hirata, Kazuta

    1992-01-01

    Development of detailed numerical models of a bearing and the related isolation system Is necessary for establishing the rational design of the bearing and the system. The developed numerical models should be validated regarding the physical parameters and the basic assumption by comparing the experimental results with the numerical ones. The numerical work being conducted in CRIEPI consists of the following items: (1) Simple modeling of the behavior of the bearings capable of approximating the tests on bearings, and the validation of the model for the bearing by comparing the numerical results adopting the models with the shaking table tests results; (2) Detailed three-dimensional modeling of single bearings with finite-element codes, and the experimental validation of the model; (3)Simple and detailed three-dimensional modeling of isolation buildings and experimental validation

  8. Gen-2 Hand-Held Optical Imager towards Cancer Imaging: Reflectance and Transillumination Phantom Studies

    Directory of Open Access Journals (Sweden)

    Anuradha Godavarty

    2012-02-01

    Full Text Available Hand-held near-infrared (NIR optical imagers are developed by various researchers towards non-invasive clinical breast imaging. Unlike these existing imagers that can perform only reflectance imaging, a generation-2 (Gen-2 hand-held optical imager has been recently developed to perform both reflectance and transillumination imaging. The unique forked design of the hand-held probe head(s allows for reflectance imaging (as in ultrasound and transillumination or compressed imaging (as in X-ray mammography. Phantom studies were performed to demonstrate two-dimensional (2D target detection via reflectance and transillumination imaging at various target depths (1–5 cm deep and using simultaneous multiple point illumination approach. It was observed that 0.45 cc targets were detected up to 5 cm deep during transillumination, but limited to 2.5 cm deep during reflectance imaging. Additionally, implementing appropriate data post-processing techniques along with a polynomial fitting approach, to plot 2D surface contours of the detected signal, yields distinct target detectability and localization. The ability of the gen-2 imager to perform both reflectance and transillumination imaging allows its direct comparison to ultrasound and X-ray mammography results, respectively, in future clinical breast imaging studies.

  9. The effect of smartphone addiction on hand joints in psoriatic patients: an ultrasound-based study.

    Science.gov (United States)

    Megna, M; Gisonni, P; Napolitano, M; Orabona, G Dell'Aversano; Patruno, C; Ayala, F; Balato, N

    2018-01-01

    Distal interphalangeal (DIP) arthritis is a frequent form of psoriatic arthritis being often linked to nail psoriasis. Modern society is characterized by overuse of smartphones. Indeed, literature has recently focalized on research into smartphone addiction and health-related problems. As smartphone addiction is able to determine overuse and repeated movements of DIP joints and nails, the aim of this study was to evaluate the impact of smartphone use on hand joints of young psoriatic patients. An observational study involving four different groups such as non-smartphone-addicted (SA) psoriatic patients, SA psoriatic patients, non-SA controls and SA controls was performed. Each subject underwent an ultrasound examination of both hands by three independent and blinded to group assignment radiologists. A specific score was used to evaluate the inflammatory state of the analysed joints. The total ultrasound score was statistically significantly higher in SA controls respect to non-SA controls (3.4 vs. 1.4; P Smartphone overuse was found to be linked with higher signs of inflammation of musculoskeletal structures of hands joints in both psoriasis and controls through ultrasound examination. Therefore, smartphone overuse may be a factor which facilitate or speed up the possible development of psoriatic arthritis. © 2017 European Academy of Dermatology and Venereology.

  10. Hospital hand hygiene opportunities: where and when (HOW2)? The HOW2 Benchmark Study.

    Science.gov (United States)

    Steed, Connie; Kelly, J William; Blackhurst, Dawn; Boeker, Sue; Diller, Thomas; Alper, Paul; Larson, Elaine

    2011-02-01

    Measurement and monitoring of health care workers' hand hygiene compliance (i.e., actions/opportunities) is a key component of strategies to eliminate hospital-acquired infections. Little data exist on the expected number of hand hygiene opportunities (HHOs) in various hospital settings, however. The purpose of this study was to estimate HHOs in 2 types of hospitals--large teaching and small community--and 3 different clinical areas-medical-surgical intensive care units, general medical wards, and emergency departments. HHO data were collected through direct observations using the World Health Organization's monitoring methodology. Estimates of HHOs were developed for 12-hour AM/PM shifts and 24-hour time frames. During 436.7 hours of observation, 6,640 HHOs were identified. Estimates of HHOs ranged from 30 to 179 per patient-day on inpatient wards and from 1.84 to 5.03 per bed-hour in emergency departments. Significant differences in HHOs were found between the 2 hospital types and among the 3 clinical areas. This study is the first to use the World Health Organization's data collection methodology to estimate HHOs in general medical wards and emergency departments. These data can be used as denominator estimates to calculate hand hygiene compliance rates when product utilization data are available. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  11. Functional and morphological studies of photodamaged skin on the hands of middle-aged Japanese golfers.

    Science.gov (United States)

    Kikuchi-Numagami, K; Suetake, T; Yanai, M; Takahashi, M; Tanaka, M; Tagami, H

    2000-06-01

    The skin of golfers' hands provides a suitable model to study the effect of chronic sun exposure, because one of their hands is exposed to the outer environment, especially sunlight, while the other one is always protected by a glove during play. Our purpose was to find out the influence of photodamage on the properties of the skin surface of middle-aged Japanese by using non-invasive methods. We measured hydration state, and water barrier function of the stratum corneum (SC) and the color of the skin of the dorsum of the hands. In a separate study, we evaluated the skin surface contour by using replicas taken from the skin in a slightly stretched or relaxed position. We found a significant decrease in hydration of the skin surface of the exposed skin as compared to that of the protected skin, whereas no such difference was found with transepidermal water loss, a parameter for water barrier function of the SC. Luminance of skin color was also reduced in the sun-exposed skin. Replica analysis revealed that large wrinkles developing in a relaxed position were more prominent on the exposed than on the protected skin, while fine furrows noted in a slightly stretched position were shallower on the former than the latter. The data obtained indicate that the chronically exposed skin of golfers' hands shows morphological and functional changes resulting from long time exposure to the outer environment especially sunlight. Furthermore, bioengineering non-invasive methods are found to be useful to detect early photodamage of the skin in a more quantitative fashion which is rather difficult to demonstrate clinically.

  12. Hand Fractures

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy ... DESCRIPTION The bones of the hand serve as a framework. This framework supports the muscles that make the wrist and fingers move. When ...

  13. Experimental and numerical study of pleated filters clogging

    International Nuclear Information System (INIS)

    Gervais, Pierre-Colin

    2013-01-01

    Pleated filters are widely used in air treatments because of the advantageous effective surface to overall dimension ratio they offer. Their major drawback though resides in their reduced lifetime which still needs to be controlled. Indeed, when clogging, the pressure drop considerably increases, the filtration flow is then no longer maintained which might lead to the deterioration of the media. It is then crucial to characterize the evolution of the pressure drop under operating conditions in order to best design these equipments. Part of our work consisted in studying how the operating conditions influence the geometry of the deposit. To do so, we used Single- Photon Emission Computed Tomography (SPECT), a non-destructive imaging technique that keeps intact the particle structuring. The visualization of aerosol deposit at the beginning of the filtration process allows observing preferential particle deposition on the whole height of the pleat. A numerical approach was used to study the permeability of bimodal fibrous media and we experimentally studied the local velocity as well as the biphasic flow inside pleated filter media. Comparison between experiments and simulations allowed us to validate the Geodict code for a wide range of media properties and velocities. Regarding bimodal fibrous media, the fast data acquisition has allowed testing several existing models which resulted in classifying them in a unique way. If the experimental results on the initial deposition in pleated filters are encouraging, those related to beforehand clogging point to several improvements regarding the technique we used. (author) [fr

  14. Numerical study of heat transfer characteristics in BOG heat exchanger

    Science.gov (United States)

    Yan, Yan; Pfotenhauer, John M.; Miller, Franklin; Ni, Zhonghua; Zhi, Xiaoqin

    2016-12-01

    In this study, a numerical study of turbulent flow and the heat transfer process in a boil-off liquefied natural gas (BOG) heat exchanger was performed. Finite volume computational fluid dynamics and the k - ω based shear stress transport model were applied to simulate thermal flow of BOG and ethylene glycol in a full-sized 3D tubular heat exchanger. The simulation model has been validated and compared with the engineering specification data from its supplier. In order to investigate thermal characteristics of the heat exchanger, velocity, temperature, heat flux and thermal response were studied under different mass flowrates in the shell-side. The shell-side flow pattern is mostly determined by viscous forces, which lead to a small velocity and low temperature buffer area in the bottom-right corner of the heat exchanger. Changing the shell-side mass flowrate could result in different distributions of the shell-side flow. However, the distribution in the BOG will remain in a relatively stable pattern. Heat flux increases along with the shell-side mass flowrate, but the increase is not linear. The ratio of increased heat flux to the mass flow interval is superior at lower mass flow conditions, and the threshold mass flow for stable working conditions is defined as greater than 0.41 kg/s.

  15. Numerical Study of Concentration Characteristics of Linear Fresnel Reflector System

    International Nuclear Information System (INIS)

    Lee, Hyun Jin; Kim, Jong Kyu; Lee, Sang Nam

    2015-01-01

    In this study, we numerically investigated the concentration characteristics of a linear Fresnel reflector system that can drive a solar thermal absorption refrigeration system to be installed in Saudi Arabia. Using an optical modeling program based on the Monte Carlo ray-tracing method, we simulated the concentrated solar flux, concentration efficiency, and concentrated solar energy on four representative days of the year - the vernal equinox, summer solstice, autumnal equinox, and winter solstice. Except the winter solstice, the concentrations were approximately steady from 9 AM to 15 PM, and the concentration efficiencies exceed 70%. Moreover, the maximum solar flux around the solar receiver center changes only within the range of 13.0 - 14.6 kW/m 2 . When we investigated the effects of the receiver installation height, reflector width, and reflector gap, the optimal receiver installation height was found to be 5 m. A smaller reflector width had a greater concentration efficiency. However, the design of the reflector width should be based on the capacity of the refrigeration system because it dominantly affects the concentrated solar energy. The present study was an essential prerequisite for thermal analyses of the solar receiver. Thus, an optical-thermal integration study in the future will assist with the performance prediction and design of the entire system

  16. Numerical Study of Concentration Characteristics of Linear Fresnel Reflector System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Jin [Kookmin Univ., Seoul (Korea, Republic of); Kim, Jong Kyu; Lee, Sang Nam [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2015-12-15

    In this study, we numerically investigated the concentration characteristics of a linear Fresnel reflector system that can drive a solar thermal absorption refrigeration system to be installed in Saudi Arabia. Using an optical modeling program based on the Monte Carlo ray-tracing method, we simulated the concentrated solar flux, concentration efficiency, and concentrated solar energy on four representative days of the year - the vernal equinox, summer solstice, autumnal equinox, and winter solstice. Except the winter solstice, the concentrations were approximately steady from 9 AM to 15 PM, and the concentration efficiencies exceed 70%. Moreover, the maximum solar flux around the solar receiver center changes only within the range of 13.0 - 14.6 kW/m{sup 2}. When we investigated the effects of the receiver installation height, reflector width, and reflector gap, the optimal receiver installation height was found to be 5 m. A smaller reflector width had a greater concentration efficiency. However, the design of the reflector width should be based on the capacity of the refrigeration system because it dominantly affects the concentrated solar energy. The present study was an essential prerequisite for thermal analyses of the solar receiver. Thus, an optical-thermal integration study in the future will assist with the performance prediction and design of the entire system.

  17. Assessing mental stress from the photoplethysmogram: a numerical study

    Science.gov (United States)

    Charlton, Peter H; Celka, Patrick; Farukh, Bushra; Chowienczyk, Phil; Alastruey, Jordi

    2018-01-01

    Abstract Objective: Mental stress is detrimental to cardiovascular health, being a risk factor for coronary heart disease and a trigger for cardiac events. However, it is not currently routinely assessed. The aim of this study was to identify features of the photoplethysmogram (PPG) pulse wave which are indicative of mental stress. Approach: A numerical model of pulse wave propagation was used to simulate blood pressure signals, from which simulated PPG pulse waves were estimated using a transfer function. Pulse waves were simulated at six levels of stress by changing the model input parameters both simultaneously and individually, in accordance with haemodynamic changes associated with stress. Thirty-two feature measurements were extracted from pulse waves at three measurement sites: the brachial, radial and temporal arteries. Features which changed significantly with stress were identified using the Mann–Kendall monotonic trend test. Main results: Seventeen features exhibited significant trends with stress in measurements from at least one site. Three features showed significant trends at all three sites: the time from pulse onset to peak, the time from the dicrotic notch to pulse end, and the pulse rate. More features showed significant trends at the radial artery (15) than the brachial (8) or temporal (7) arteries. Most features were influenced by multiple input parameters. Significance: The features identified in this study could be used to monitor stress in healthcare and consumer devices. Measurements at the radial artery may provide superior performance than the brachial or temporal arteries. In vivo studies are required to confirm these observations. PMID:29658894

  18. Numerical Study on the 1682 Tainan Historic Tsunami Event

    Science.gov (United States)

    Tsai, Y.; Wu, T.; Lee, C.; KO, L.; Chuang, M.

    2013-12-01

    We intend to reconstruct the tsunami source of the 1682/1782 tsunami event in Tainan, Taiwan, based on the numerical method. According to Soloviev and Go (1974), a strong earthquake shook the Tainan and caused severe damage, followed by tsunami waves. Almost the whole island was flooded by tsunami for over 120 km. More than 40,000 inhabitants were killed. Forts Zealand and Pigchingi were washed away. 1682/1782 event was the highest death toll in the Pacific Ocean regarded by Bryant (2001). However, the year is ambiguous in 1682 or 1782, and death toll is doubtful. We tend to believe that this event was happened in 1682 based on the evolution of the harbor name. If the 1682 tsunami event does exist, the hazard mitigation plan has to be modified, and restoring the 1682 event becomes important. In this study, we adopted the tsunami reverse tracking method (TRTM) to examine the possible tsunami sources. A series of numerical simulations were carried out by using COMCOT (Cornell Multi-grid Coupled Tsunami model), and nested grid with 30 m resolution was applied to the study area. According to the result of TRTM, the 1682 tsunami is most likely sourcing from the north segment of Manila Trench. From scenario study, we concluded that the 1682 event was triggered by an Mw >= 8.8 earthquake in north segment of Manila Trench, and 4 m wave height was observed in Tainan and its inundation range is agreeable with historical records. If this scenario occurred again, sever damage and death toll will be seen many high population cities, such as Tainan city, Kaohsiung city and Kenting, where No. 3 nuclear power plant is located. Detailed results will be presented in the full paper. Figure 1. Map of Tsunami Reverse Tracking Method (TRTM) in Tainan. Black arrow indicates direction of possible tsunami direction. The color bar denotes the magnitude of the maximum moment flux. Figure 2. Scenario result of Mw 8.8 in northern segment of Manila Trench. (Left: Initial free surface elevation

  19. Comparative evaluation of apical extrusion of bacteria using hand and rotary systems : An in vitro study

    Science.gov (United States)

    Ghivari, Sheetal B; Kubasad, Girish C; Deshpande, Preethi

    2012-01-01

    Aim: To evaluate the bacteria extruded apically during root canal preparation using two hand and rotary instrumentation techniques. Materials and Methods: Eighty freshly extracted mandibular premolars were mounted in bacteria collection apparatus. Root canals were contaminated with the pure culture of Enterococcus fecalis (ATCC 29212) and dried at 37°C for 24 h. Bacteria extruded were collected, incubated in brain heart infusion agar for 24 h at 36°C and the colony forming units (CFU) were counted. Statistical Analysis: The mean number of colony forming units were calculated by One-way ANOVA and comparison between the groups made by multiple comparison (Dunnet D) test. Results: The step-back technique extruded highest number of bacteria in comparison to other hand and rotary Ni–Ti systems. Conclusion: Under the limitation of this study all hand and rotary instrumentation techniques extruded bacteria. Among all the instrumentation techniques step-back technique extruded more number of bacteria and K-3 system the least. Further in vivo research in this direction could provide more insight into the biologic factors associated and focus on bacterial species that essentially play a major role in post instrumentation flare-ups. PMID:22368332

  20. Eating tools in hand activate the brain systems for eating action: a transcranial magnetic stimulation study.

    Science.gov (United States)

    Yamaguchi, Kaori; Nakamura, Kimihiro; Oga, Tatsuhide; Nakajima, Yasoichi

    2014-07-01

    There is increasing neuroimaging evidence suggesting that visually presented tools automatically activate the human sensorimotor system coding learned motor actions relevant to the visual stimuli. Such crossmodal activation may reflect a general functional property of the human motor memory and thus can be operating in other, non-limb effector organs, such as the orofacial system involved in eating. In the present study, we predicted that somatosensory signals produced by eating tools in hand covertly activate the neuromuscular systems involved in eating action. In Experiments 1 and 2, we measured motor evoked response (MEP) of the masseter muscle in normal humans to examine the possible impact of tools in hand (chopsticks and scissors) on the neuromuscular systems during the observation of food stimuli. We found that eating tools (chopsticks) enhanced the masseter MEPs more greatly than other tools (scissors) during the visual recognition of food, although this covert change in motor excitability was not detectable at the behavioral level. In Experiment 3, we further observed that chopsticks overall increased MEPs more greatly than scissors and this tool-driven increase of MEPs was greater when participants viewed food stimuli than when they viewed non-food stimuli. A joint analysis of the three experiments confirmed a significant impact of eating tools on the masseter MEPs during food recognition. Taken together, these results suggest that eating tools in hand exert a category-specific impact on the neuromuscular system for eating. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Comparative study of state-of-the-art myoelectric controllers for multigrasp prosthetic hands.

    Science.gov (United States)

    Segil, Jacob L; Controzzi, Marco; Weir, Richard F ff; Cipriani, Christian

    2014-01-01

    A myoelectric controller should provide an intuitive and effective human-machine interface that deciphers user intent in real-time and is robust enough to operate in daily life. Many myoelectric control architectures have been developed, including pattern recognition systems, finite state machines, and more recently, postural control schemes. Here, we present a comparative study of two types of finite state machines and a postural control scheme using both virtual and physical assessment procedures with seven nondisabled subjects. The Southampton Hand Assessment Procedure (SHAP) was used in order to compare the effectiveness of the controllers during activities of daily living using a multigrasp artificial hand. Also, a virtual hand posture matching task was used to compare the controllers when reproducing six target postures. The performance when using the postural control scheme was significantly better (p state machines during the physical assessment when comparing within-subject averages using the SHAP percent difference metric. The virtual assessment results described significantly greater completion rates (97% and 99%) for the finite state machines, but the movement time tended to be faster (2.7 s) for the postural control scheme. Our results substantiate that postural control schemes rival other state-of-the-art myoelectric controllers.

  2. Levodopa effects on hand and speech movements in patients with Parkinson's disease: a FMRI study.

    Directory of Open Access Journals (Sweden)

    Audrey Maillet

    Full Text Available Levodopa (L-dopa effects on the cardinal and axial symptoms of Parkinson's disease (PD differ greatly, leading to therapeutic challenges for managing the disabilities in this patient's population. In this context, we studied the cerebral networks associated with the production of a unilateral hand movement, speech production, and a task combining both tasks in 12 individuals with PD, both off and on levodopa (L-dopa. Unilateral hand movements in the off medication state elicited brain activations in motor regions (primary motor cortex, supplementary motor area, premotor cortex, cerebellum, as well as additional areas (anterior cingulate, putamen, associative parietal areas; following L-dopa administration, the brain activation profile was globally reduced, highlighting activations in the parietal and posterior cingulate cortices. For the speech production task, brain activation patterns were similar with and without medication, including the orofacial primary motor cortex (M1, the primary somatosensory cortex and the cerebellar hemispheres bilaterally, as well as the left- premotor, anterior cingulate and supramarginal cortices. For the combined task off L-dopa, the cerebral activation profile was restricted to the right cerebellum (hand movement, reflecting the difficulty in performing two movements simultaneously in PD. Under L-dopa, the brain activation profile of the combined task involved a larger pattern, including additional fronto-parietal activations, without reaching the sum of the areas activated during the simple hand and speech tasks separately. Our results question both the role of the basal ganglia system in speech production and the modulation of task-dependent cerebral networks by dopaminergic treatment.

  3. Numerical and experimental study of a hydrodynamic cavitation tube

    Science.gov (United States)

    Hu, H.; Finch, J. A.; Zhou, Z.; Xu, Z.

    1998-08-01

    A numerical analysis of hydrodynamics in a cavitation tube used for activating fine particle flotation is described. Using numerical procedures developed for solving the turbulent k-ɛ model with boundary fitted coordinates, the stream function, vorticity, velocity, and pressure distributions in a cavitation tube were calculated. The calculated pressure distribution was found to be in excellent agreement with experimental results. The requirement of a pressure drop below approximately 10 m water for cavitation to occur was observed experimentally and confirmed by the model. The use of the numerical procedures for cavitation tube design is discussed briefly.

  4. Experimental and numerical studies in a vortex tube

    International Nuclear Information System (INIS)

    Sohn, Chang Hyun; Kim, Chang Soo; Gowda, B. H. L Lakshmana; Jung, Ui Hyun

    2006-01-01

    The present investigation deals with the study of the internal flow phenomena of the counter-flow type vortex tube using experimental testing and numerical simulation. Visualization was carried out using the surface tracing method, injecting dye on the vortex tube wall using a needle. Vortex tube is made of acrylic to visualize the surface particle tracing and the input air pressure was varied from 0.1 MPa to 0.3 MPa. The experimentally visualized results on the tube show that there is an apparent sudden changing of the trajectory on the vortex tube wall which was observed in every experimental test case. This may indicate the stagnation position of the vortex flow. The visualized stagnation position moves towards the vortex generator with increase in cold flow ratio and input pressure. Three-dimensional computational study is also conducted to obtain more detailed flow information in the vortex tube. Calculated total pressure, static pressure and total temperature distributions in the vortex tube were in good agreement with the experimental data. The computational particle trace on the vortex tube wall is very similar to that observed in experiments

  5. Numerical study of the stopping of aura during migraine

    Directory of Open Access Journals (Sweden)

    Moussa A.

    2010-12-01

    Full Text Available This work is devoted to the study of migraine with aura in the human brain. Following [6], we class migraine as a propagation of a wave of depolarization through the cells. The mathematical model used, based on a reaction-diffusion equation, is briefly presented. The equation is considered in a duct containing a bend, in order to model one of the numerous circumvolutions of the brain. For a wide set of parameters, one can establish the existence of a critical radius below which the wave stops. The approximation scheme used for the simulations is first described and then a numerical study is realized, precising the dependence of the critical radius with respect to the different parameters of the model. Ce travail est consacré à l’étude de l’évolution d’une migraine avec aura dans le cerveau humain. Suivant [6], nous assimilons la migraine à une onde de dépolarisation attaquant les cellules du cerveau. Le modèle mathématique retenu, basé sur une équation de réaction-diffusion, est brièvement rappelé. Le domaine d’espace utilisé est constitué d’un conduit présentant un coude, afin de représenter l’une des nombreuses circonvolutions cérébrales. Pour une importante classe de paramètres, il est possible de mettre en évidence l’existence d’un rayon critique au delà duquel le front d’onde n’arrive pas à dépasser le coude. Après une description du schéma d’approximation utilisé, une étude numérique a été réalisée, visant à préciser la dépendance du rayon critique en fonction des différents paramètres du modèle.

  6. Complexities in coastal sediment transport studies by numerical modelling

    Digital Repository Service at National Institute of Oceanography (India)

    Ilangovan, D.; ManiMurali, R.

    equations arrived based on scientific principles as all natural phenomena are governed by certain rules which can be explained by scientific principles. Efficiency of numerical modeling greatly depends on quality of input parameters. When input parameters...

  7. Case studies in the numerical solution of oscillatory integrals

    International Nuclear Information System (INIS)

    Adam, G.

    1992-06-01

    A numerical solution of a number of 53,249 test integrals belonging to nine parametric classes was attempted by two computer codes: EAQWOM (Adam and Nobile, IMA Journ. Numer. Anal. (1991) 11, 271-296) and DO1ANF (Mark 13, 1988) from the NAG library software. For the considered test integrals, EAQWOM was found to be superior to DO1ANF as it concerns robustness, reliability, and friendly user information in case of failure. (author). 9 refs, 3 tabs

  8. NUMERICAL STUDY OF THE VISHNIAC INSTABILITY IN SUPERNOVA REMNANTS

    International Nuclear Information System (INIS)

    Michaut, C.; Cavet, C.; Bouquet, S. E.; Roy, F.; Nguyen, H. C.

    2012-01-01

    The Vishniac instability is thought to explain the complex structure of radiative supernova remnants in their Pressure-Driven Thin Shell (PDTS) phase after a blast wave (BW) has propagated from a central explosion. In this paper, the propagation of the BW and the evolution of the PDTS stage are studied numerically with the two-dimensional (2D) code HYDRO-MUSCL for a finite-thickness shell expanding in the interstellar medium (ISM). Special attention is paid to the adiabatic index, γ, and three distinct values are taken for the cavity (γ 1 ), the shell (γ 2 ), and the ISM (γ 3 ) with the condition γ 2 1 , γ 3 . This low value of γ 2 accounts for the high density in the shell achieved by a strong radiative cooling. Once the spherical background flow is obtained, the evolution of a 2D-axisymmetric perturbation is computed from the linear to the nonlinear regime. The overstable mechanism, previously demonstrated theoretically by E. T. Vishniac in 1983, is recovered numerically in the linear stage and is expected to produce and enhance anisotropies and clumps on the shock front, leading to the disruption of the shell in the nonlinear phase. The period of the increasing oscillations and the growth rate of the instability are derived from several points of view (the position of the perturbed shock front, mass fluxes along the shell, and density maps), and the most unstable mode differing from the value given by Vishniac is computed. In addition, the influence of several parameters (the Mach number, amplitude and wavelength of the perturbation, and adiabatic index) is examined and for wavelengths that are large enough compared to the shell thickness, the same conclusion arises: in the late stage of the evolution of the radiative supernova remnant, the instability is dampened and the angular initial deformation of the shock front is smoothed while the mass density becomes uniform with the angle. As a result, our model shows that the supernova remnant returns to a

  9. Numerical study of free pulsed jet flow with variable density

    Energy Technology Data Exchange (ETDEWEB)

    Kriaa, Wassim [Laboratoire de Mecanique des Fluides et Thermique, Ecole Nationale d' Ingenieurs de Monastir, Route de Ouardanine, 5000 Monastir (Tunisia)], E-mail: kriaawass@yahoo.fr; Cheikh, Habib Ben; Mhiri, Hatem [Laboratoire de Mecanique des Fluides et Thermique, Ecole Nationale d' Ingenieurs de Monastir, Route de Ouardanine, 5000 Monastir (Tunisia); Le Palec, Georges; Bournot, Philippe [Institut de Mecanique de Marseille, 60 rue Juliot Curie Technopole de Chateau-Gombert 13453, Marseille Cedex 13 (France)

    2008-05-15

    In this work, we propose a numerical study of a free pulsed plane jet with variable density in unsteady and laminar modes. At the nozzle exit, the flow is characterized by a uniform temperature and submitted to a longitudinal and periodic velocity disturbance: u = u{sub 0}(1 + A sin({omega}t)). A finite difference method is performed to solve the equations governing this flow type. The discussion relates to the effect of the most significant parameters, such as the pulsation frequency and amplitude, on the flow characteristic fields. The effects of Reynolds and Galileo numbers was also examined. The results show that the pulsation affects the flow in the vicinity of the nozzle, and further, the results of the unsteady mode join those of the steady non-pulsed jet. The results state also that the Strouhal number has no influence on the flow mixture degree, whereas the amplitude of pulsation affects, in a remarkable way, the mixture and, consequently, the concentration core length.

  10. Monte Carlo numerical study of lattice field theories

    International Nuclear Information System (INIS)

    Gan Cheekwan; Kim Seyong; Ohta, Shigemi

    1997-01-01

    The authors are interested in the exact first-principle calculations of quantum field theories which are indeed exact ones. For quantum chromodynamics (QCD) at low energy scale, a nonperturbation method is needed, and the only known such method is the lattice method. The path integral can be evaluated by putting a system on a finite 4-dimensional volume and discretizing space time continuum into finite points, lattice. The continuum limit is taken by making the lattice infinitely fine. For evaluating such a finite-dimensional integral, the Monte Carlo numerical estimation of the path integral can be obtained. The calculation of light hadron mass in quenched lattice QCD with staggered quarks, 3-dimensional Thirring model calculation and the development of self-test Monte Carlo method have been carried out by using the RIKEN supercomputer. The motivation of this study, lattice QCD formulation, continuum limit, Monte Carlo update, hadron propagator, light hadron mass, auto-correlation and source size dependence are described on lattice QCD. The phase structure of the 3-dimensional Thirring model for a small 8 3 lattice has been mapped. The discussion on self-test Monte Carlo method is described again. (K.I.)

  11. A Numerical and Experimental Study of Local Exhaust Capture Efficiency

    DEFF Research Database (Denmark)

    Madsen, U.; Breum, N. O.; Nielsen, Peter Vilhelm

    1993-01-01

    Direct capture efficiency of a local exhaust system is defined by introducing an imaginary control box surrounding the contaminant source and the exhaust opening. The imaginary box makes it possible to distinguish between contaminants directly captured and those that escape. Two methods for estim...... location is less important for the case studied. The choice of sampling strategy to obtain a representative background concentration is essential as substantial differences on direct capture efficiency are found. Recommendations are given......Direct capture efficiency of a local exhaust system is defined by introducing an imaginary control box surrounding the contaminant source and the exhaust opening. The imaginary box makes it possible to distinguish between contaminants directly captured and those that escape. Two methods...... for estimation of direct capture efficiency are given: (1) a numerical method based on the time-averaged Navier-Stokes equations for turbulent flows; and (2) a field method based on a representative background concentration. Direct capture efficiency is sensitive to the size of the control box, whereas its...

  12. Basic study on the rectangular numeric keys for touch screen.

    Science.gov (United States)

    Harada, H; Katsuura, T; Kikuchi, Y

    1997-06-01

    The present study was conducted to examine the optimum inter-key spacing of numeric rectangular keys for touch screens. Six male students (22-25 years old) and three female students (21-24 years old) participated in the experiment. Each subject performed the data entry task using rectangular keys of touch devices. These keys were arranged in both horizontal and vertical layouts. The sizes of the rectangular keys in both layouts were 12 x 21 mm and 15 x 39 mm, and each of the inter-key spacing of each key was 0, 3, 6, 12 and 21 mm. The response time with inter-key spacing of 3 mm was significantly faster than with the inter-key spacing of 0, 12 and 21 mm (p < 0.05). Keys of vertical position produced faster response time than that of horizontal position. The subjective ratings showed that the inter-key spacing of 6 mm was significantly better than the inter-key spacing of 0, 3, 12 and 21 mm (p < 0.05).

  13. Numerical study of similarity in prototype and model pumped turbines

    International Nuclear Information System (INIS)

    Li, Z J; Wang, Z W; Bi, H L

    2014-01-01

    Similarity study of prototype and model pumped turbines are performed by numerical simulation and the partial discharge case is analysed in detail. It is found out that in the RSI (rotor-stator interaction) region where the flow is convectively accelerated with minor flow separation, a high level of similarity in flow patterns and pressure fluctuation appear with relative pressure fluctuation amplitude of model turbine slightly higher than that of prototype turbine. As for the condition in the runner where the flow is convectively accelerated with severe separation, similarity fades substantially due to different topology of flow separation and vortex formation brought by distinctive Reynolds numbers of the two turbines. In the draft tube where the flow is diffusively decelerated, similarity becomes debilitated owing to different vortex rope formation impacted by Reynolds number. It is noted that the pressure fluctuation amplitude and characteristic frequency of model turbine are larger than those of prototype turbine. The differences in pressure fluctuation characteristics are discussed theoretically through dimensionless Navier-Stokes equation. The above conclusions are all made based on simulation without regard to the penstock response and resonance

  14. Numerical study of glare spot phase Doppler anemometry

    Science.gov (United States)

    Hespel, C.; Ren, K. F.; Gréhan, G.; Onofri, F.

    2008-03-01

    The phase Doppler anemometry has (PDA) been developed to measure simultaneously the velocity and the size of droplets. When the concentration of particles is high, tightly focused beams must be used, as in the dual burst PDA. The latter permits an access to the refractive index of the particle, but the effect of wave front curvature of the incident beams becomes evident. In this paper, we introduce a glare spot phase Doppler anemometry which uses two large beams. The images of the particle formed by the reflected and refracted light, known as glare spots, are separated in space. When a particle passes through the probe volume, the two parts in a signal obtained by a detector in forward direction are then separated in time. If two detectors are used the phase differences and the intensity ratios between two signals, the distance between the reflected and refracted spots can be obtained. These measured values provide information about the particle diameter and its refractive index, as well as its two velocity components. This paper is devoted to the numerical study of such a configuration with two theoretical models: geometrical optics and rigorous electromagnetism solution.

  15. Numerical study of optimal equilibrium cycles for pressurized water reactors

    International Nuclear Information System (INIS)

    Mahlers, Y.P.

    2003-01-01

    An algorithm based on simulated annealing and successive linear programming is applied to solve equilibrium cycle optimization problems for pressurized water reactors. In these problems, the core reload scheme is represented by discrete variables, while the cycle length as well as uranium enrichment and loading of burnable poison in each feed fuel assembly are treated as continuous variables. The enrichments are considered to be distinct in all feed fuel assemblies. The number of batches and their sizes are not fixed and also determined by the algorithm. An important feature of the algorithm is that all the parameters are determined by the solution of one optimization problem including both discrete and continuous variables. To search for the best reload scheme, simulated annealing is used. The optimum cycle length as well as uranium enrichment and loading of burnable poison in each feed fuel assembly are determined for each reload pattern examined using successive linear programming. Numerical results of equilibrium cycle optimization for various values of the effective price of electricity and fuel reprocessing cost are studied

  16. Thermalization of positronium in helium: A numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Marjanovic, S.; Suvakov, M. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Engbrecht, J.J. [Saint Olaf College, Northfield, MN 55057 (United States); Petrovic, Z.Lj., E-mail: zoran@ipb.ac.rs [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)

    2012-05-15

    In this paper we present a numerical study of positronium (Ps) thermalization in pure helium (He). Recent measurements of Ps thermalization yielded data that were analyzed to produce the scattering cross-sections in helium by using energy balance equations with an assumption of a Maxwell-Boltzmann distribution (MBD) function for Ps. We have applied a Monte Carlo code to test the cross-sections. As our code was developed without any approximations for the energy distribution function we have effectively also tested the assumptions and the validity of the simple theory based on Maxwellian distributions. We present the simulation results using the simulation technique that is limited only by the accuracy of the available cross-sections. We calculate thermalization profiles for several theoretical and measured cross-sections. Also, the temporal evolution of energy distributions has been shown along with diffusion coefficients and spatial ranges of penetration. Thermalization of the initial distribution is rapid and the data follow relatively closely, those calculated in recent experiment, which supports the choice of MBD and the obtained cross-section. However the distribution function most of the time deviates from the MBD due to strong scattering. Finally, we applied the same procedure to analyze Ps thermalization in water vapor.

  17. Numerical and experimental study of bistable plates for morphing structures

    Science.gov (United States)

    Nicassio, F.; Scarselli, G.; Avanzini, G.; Del Core, G.

    2017-04-01

    This study is concerned with the activation energy threshold of bistable composite plates in order to tailor a bistable system for specific aeronautical applications. The aim is to explore potential configurations of the bistable plates and their dynamic behavior for designing novel morphing structure suitable for aerodynamic surfaces and, as a possible further application, for power harvesters. Bistable laminates have two stable mechanical shapes that can withstand aerodynamic loads without additional constraint forces or locking mechanisms. This kind of structures, when properly loaded, snap-through from one stable configuration to another, causing large strains that can also be used for power harvesting scopes. The transition between the stable states of the composite laminate can be triggered, in principle, simply by aerodynamic loads (pilot, disturbance or passive inputs) without the need of servo-activated control systems. Both numerical simulations based on Finite Element models and experimental testing based on different activating forcing spectra are used to validate this concept. The results show that dynamic activation of bistable plates depend on different parameters that need to be carefully managed for their use as aircraft passive wing flaps.

  18. Numerical study of flame structure in the mild combustion regime

    Directory of Open Access Journals (Sweden)

    Mardani Amir

    2015-01-01

    Full Text Available In this paper, turbulent non-premixed CH4+H2 jet flame issuing into a hot and diluted co-flow air is studied numerically. This flame is under condition of the moderate or intense low-oxygen dilution (MILD combustion regime and related to published experimental data. The modelling is carried out using the EDC model to describe turbulence-chemistry interaction. The DRM-22 reduced mechanism and the GRI2.11 full mechanism are used to represent the chemical reactions of H2/methane jet flame. The flame structure for various O2 levels and jet Reynolds numbers are investigated. The results show that the flame entrainment increases by a decrease in O2 concentration at air side or jet Reynolds number. Local extinction is seen in the upstream and close to the fuel injection nozzle at the shear layer. It leads to the higher flame entertainment in MILD regime. The turbulence kinetic energy decay at centre line of jet decreases by an increase in O2 concentration at hot Co-flow. Also, increase in jet Reynolds or O2 level increases the mixing rate and rate of reactions.

  19. Drag Reduction by Riblets & Sharkskin Denticles: A Numerical Study

    Science.gov (United States)

    Boomsma, Aaron

    Riblet films are a passive method of turbulent boundary layer control that can reduce viscous drag. They have been studied with great detail for over 30 years. Although common riblet applications include flows with Adverse Pressure Gradients (APG), nearly all research thus far has been performed in channel flows. Recent research has provided motivation to study riblets in more complicated turbulent flows with claims that riblet drag reduction can double in mild APG common to airfoils at moderate angles of attack. Therefore, in this study, we compare drag reduction by scalloped riblet films between riblets in a zero pressure gradient and those in a mild APG using high-resolution large eddy simulations. In order to gain a fundamental understanding of the relationship between drag reduction and pressure gradient, we simulated several different riblet sizes that encompassed a broad range of s + (riblet width in wall units), similarly to many experimental studies. We found that there was only a slight improvement in drag reduction for riblets in the mild APG. We also observed that peak values of streamwise turbulence intensity, turbulent kinetic energy, and streamwise vorticity scale with riblet width. Primary Reynolds shear stresses and turbulence kinetic energy production however scale with the ability of the riblet to reduce skin-friction. Another turbulent roughness of similar shape and size to riblets is sharkskin. The hydrodynamic function of sharkskin has been under investigation for the past 30 years. Current literature conflicts on whether sharkskin is able to reduce skin friction similarly to riblets. To contribute insights toward reconciling these conflicting views, Direct Numerical Simulations (DNS) are carried out to obtain detailed flow fields around realistic denticles. A sharp interface immersed boundary method is employed to simulate two arrangements of actual sharkskin denticles (from Isurus oxyrinchus) in a turbulent boundary layer at Retau ≈ 180

  20. Numerical study of circular synthetic jets at low Reynolds numbers

    International Nuclear Information System (INIS)

    Xia, Qingfeng; Lei, Shenghui; Ma, Jieyan; Zhong, Shan

    2014-01-01

    Highlights: • Parameter maps depicting different flow regimes of synthetic jets are produced. • Boundaries separating these regimes are defined using quantitative criteria. • The Reynolds number is most appropriate for classifying different flow regimes. • A use of high suction cycle factors enhances the effectiveness of synthetic jets. - Abstract: In this paper, the flow patterns of circular synthetic jets issuing into a quiescent flow at low Reynolds numbers are studied numerically. The results confirm the presence of the three jet flow regimes, i.e. no jet formation, jet flow without rollup and jet flow with rollup reported in the literature. The boundaries of the different jet flow regimes are determined by tracking the structures produced by the synthetic jets in the near field of the jet orifice over several actuation cycles and examining the cycle-averaged streamwise velocity profiles along the jet central axis. When the Stokes number is above a certain threshold value appropriate for the corresponding flow regime, a good correlation between the flow patterns and the jet Reynolds number defined using the jet orifice diameter, Re Do , is also found. Furthermore, the flow structures of synthetic jets with different suction duty cycle factors are compared. The use of a high suction duty cycle factor strengthens the synthetic jet resulting in a greater penetration depth into the surrounding fluid. Overall, the finding from this study enables the flow regimes, in which a synthetic jet actuator with a circular orifice operates, to be determined. It also provides a way of designing more effective synthetic jet actuators for enhancing mass and momentum transfer at very low Reynolds numbers

  1. Studies of imaging characteristics for a slab of a lossy left-handed material

    International Nuclear Information System (INIS)

    Shen Linfang; He Sailing

    2003-01-01

    The characteristics of an imaging system formed by a slab of a lossy left-handed material (LHM) are studied. The transfer function of the LHM imaging system is written in an appropriate product form with each term having a clear physical interpretation. A tiny loss of the LHM may suppress the transmission of evanescent waves through the LHM slab and this is explained physically. An analytical expression for the resolution of the imaging system is derived. It is shown that it is impossible to make a subwavelength imaging by using a realistic LHM imaging system unless the LHM slab is much thinner than the wavelength

  2. Study of left-handed characteristics of parallel microwires based metastructures

    Energy Technology Data Exchange (ETDEWEB)

    Olariu, C.S., E-mail: csolariu@phys-iasi.ro [National Institute of Research and Development for Technical Physics, Iasi (Romania); Ababei, G.; Lupu, N.; Chiriac, H. [National Institute of Research and Development for Technical Physics, Iasi (Romania)

    2016-04-01

    The aim of this work is to present a complex experimental and theoretical study of the ferromagnetic resonance frequencies and plasma behavior for CoFe-based, Co-based, Fe-based and FINEMET{sup TM} glass covered amorphous microwires (GCAWs), arranged in parallel configurations as free-standing systems, as well as combinations thereof, in order to obtain metastructures with tailored and enlarged left-handed frequency domain. The negative magnetic properties interval of the metastructures is expanded by alternating different types of GCAWs with close natural ferromagnetic resonance (NFMR) and natural antiferromagnetic resonance (NFMAR) domains, respectively.

  3. Knowledge, Attitudes, and Practices Study on Hand Hygiene Among Imam Hossein Hospital’s Residents in 2013

    Science.gov (United States)

    Nabavi, Mahmoud; Alavi-Moghaddam, Mostafa; Gachkar, Latif; Moeinian, Mohammad

    2015-01-01

    Background: Hand hygiene is considered one of the most important infection control measures for preventing health care-associated infections. Although the techniques involved in hand hygiene are simple, compliance with hand hygiene recommendations is poor worldwide. Objectives: We sought to perform a knowledge, attitudes, and practices (KAP) study on hand hygiene among medical residents at Imam Hossein hospital, Tehran, Iran. Patients and Methods: This cross-sectional KAP study was conducted among medical residents in Imam Hossein hospital, Iran, 2013. All medical residents from different wards were invited to participate in this study (270 in total). The world health organization questionnaires and an observational checklist were used to collect data. The χ2 test and the Fisher exact test were utilized to analyze the qualitative variables. Since the quantitative variables had no normal distribution, the Mann-Whitney test and the Kruskal-Wallis method were employed. A P value hand hygiene, and only 20.16% (n = 25) managed to identify the correct answer. Moreover, 3.1% (n = 8) of the residents adhered to the 8 standard steps, 12.1% (n = 31) washed their hands for 20 - 30 seconds, and only 2 residents observed the sequences of hand hygiene. Additionally, none of the residents performed hand washing with available means (water and hand-washing liquid) in the morning visit hours. Conclusions: Concerning hand hygiene, the residents had moderate knowledge but overall poor attitudes and practices. The present study underscores the need for further improvement in the existing training programs to address the gaps in KAP regarding hand hygiene. PMID:26568858

  4. Association between grip strength and hand and knee radiographic osteoarthritis in Korean adults: Data from the Dong-gu study.

    Directory of Open Access Journals (Sweden)

    Lihui Wen

    Full Text Available We assessed whether grip strength was related to various types of radiographic damage in Korean adults with osteoarthritis (OA.Data from 2,251 subjects enrolled in the Dong-gu study, who had no hand joint pain, were analyzed to investigate the relationship between grip strength and OA. Hand grip strength was measured using a hand-held dynamometer, and radiographs of the hand and knee were scored according to a semi-quantitative grading system. Multiple linear regressions were used to explore associations between grip strength and radiographic features of OA.Grip strength in men and women was negatively related to hand (both p < 0.001 and knee (men, p < 0.001; women, p = 0.010 OA after adjusting for confounders. Hand (men, p < 0.001; women, p = 0.001 and knee (both p < 0.001 joint space narrowing (JSN showed the strongest associations with low grip strength, regardless of gender. Moreover, the severity of hand osteophytes in women (p = 0.001, and subchondral cysts (men, p < 0.001 was correlated with low grip strength in both genders.Among subjects without hand joint pain, low grip strength was associated significantly with hand and knee radiographic OA, regardless of gender. Among all types of OA radiographic damage, low grip strength showed the strongest association with JSN.

  5. Numerical study of emergency cryogenics gas relief into confined spaces

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The presented work focuses on the risk analysis and the consequences of the unexpected leak to the tunnel of cryogenics gases. Formation of the gas mixture and its propagation along tunnels is an important issue for the safe operation of cryogenic machines, including superconducting accelerators or free electron lasers. As the cryogenics gas the helium and argon will be considered. A minimal numerical model will be presented and discussed. Series of numerical results related to emergency helium relief to the CERN tunnel and related to unexpected leak of the argon to an underground tunnel, will be shown. The numerical results will show temperature distribution, oxygen deficiency and gas cloud propagation in function of intensity of the leak and intensity of the ventilation.

  6. Economic impact of hand and wrist injuries: Health-care costs and productivity costs in a population-based study

    NARCIS (Netherlands)

    C.E. de Putter (Dennis); R.W. Selles (Ruud); S. Polinder (Suzanne); M.J.M. Panneman (Martien); S.E.R. Hovius (Steven); E.F. van Beeck (Ed)

    2012-01-01

    textabstractBackground: Injuries to the hand and wrist account for approximately 20% of patient visits to emergency departments and may impose a large economic burden. The purpose of this study was to estimate the total health-care costs and productivity costs of injuries to the hand and wrist and

  7. Effects of Neoprene Wrist/Hand Splints on Handwriting for Students with Joint Hypermobility Syndrome: A Single System Design Study

    Science.gov (United States)

    Frohlich, Lauren; Wesley, Alison; Wallen, Margaret; Bundy, Anita

    2012-01-01

    Purpose: Pain associated with hypermobility of wrist and hand joints can contribute to decreased handwriting output. This study examined the effectiveness of a neoprene wrist/hand splint in reducing pain and increasing handwriting speed and endurance for students with joint hypermobility syndrome. Methods: Multiple baseline, single system design…

  8. Hand Therapy

    Science.gov (United States)

    ... from conditions such as carpal tunnel syndrome and tennis elbow , as well as from chronic problems such as ... Tools Advice from a Certified Hand Therapist on Tennis Elbow Advice from a Certified Hand Therapist: Living with( ...

  9. Randomized crossover study evaluating the effect of a hand sanitizer dispenser on the frequency of hand hygiene among anesthesiology staff in the operating room.

    Science.gov (United States)

    Munoz-Price, L Silvia; Patel, Zalak; Banks, Shawn; Arheart, Kristopher; Eber, Scott; Lubarsky, David A; Birnbach, David J

    2014-06-01

    Forty anesthesia providers were evaluated with and without hand sanitizer dispensers present on the anesthesia machine. Having a dispenser increased the frequency of hand hygiene only from 0.5 to 0.8 events per hour (P = .01). Other concomitant interventions are needed to further increase hand hygiene frequency among anesthesia providers.

  10. Combustion behaviour of pulverised wood - Numerical and experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Lixin Tao [TPS Termiska Processer AB, Nykoeping (Sweden)

    2002-05-01

    This report presents the experimental results achieved in an on-going project financed by STEM (Energimyndigheten) within the research program 'Gasification and combustion of solid fuels', during the first phase of the project (2001-03-05 to 2002-03-05). The project is a collaboration project between LTH and TPS on combined numerical modelling/experimental investigation on combustion of pulverised wood. Particularly TPS carry out the experimental investigation in a laboratory vertical furnace. During the project, the experimental rig has been developed. The experimental furnace has an inner diameter of 0.25 m and a height of 4 m. A pulverised wood flame is established using an axial burner that is installed on the top of the furnace. Experimental study on a selected pulverised wood with determined size distribution and anisotropy character has been carried out in this furnace. During the experiment, the wall temperatures of the furnace were continuously measured using 8 thermocouples of type K that are installed on the wall with a spacing about 0.5 m. The gas temperatures in the furnace were monitored using 5 fixed suction pyrometers that are placed along the centre of the furnace. At the bottom of the furnace, a fixed gas-sampling probe was installed. The flue gas concentrations were continuously monitored with on-line gas analysers. The extent of combustion was measured through the analysis of sampled gaseous products and condensable solid products. A movable liquid quench probe was used to carry out the gas and solid sampling through a number of sampling holes that are opened along the furnace wall. The quench liquor used is an alkaline water solution containing a small amount of a detergent to dissolve HCN and tar. The quench liquor and solid samples were separated and collected in a knockout pot. The gas was filtered and passed through two bubblers with acidic solution to collect NH{sub 3}. The gas concentrations were then analysed with on-line gas

  11. A Numerical Study of Quantization-Based Integrators

    Directory of Open Access Journals (Sweden)

    Barros Fernando

    2014-01-01

    Full Text Available Adaptive step size solvers are nowadays considered fundamental to achieve efficient ODE integration. While, traditionally, ODE solvers have been designed based on discrete time machines, new approaches based on discrete event systems have been proposed. Quantization provides an efficient integration technique based on signal threshold crossing, leading to independent and modular solvers communicating through discrete events. These solvers can benefit from the large body of knowledge on discrete event simulation techniques, like parallelization, to obtain efficient numerical integration. In this paper we introduce new solvers based on quantization and adaptive sampling techniques. Preliminary numerical results comparing these solvers are presented.

  12. Numerical study of interfacial flows with immersed solids

    International Nuclear Information System (INIS)

    Kim, Sung Il; Son, Gi Hun

    2003-01-01

    A numerical method is presented for computing unsteady incompressible two-phase flows with immersed solids. The method is based on a level set technique for capturing the phase interface, which is modified to satisfy a contact angle condition at the solid-fluid interface as well as to achieve mass conservation during the whole calculation procedure. The modified level set method is applied for numerical simulation of bubble deformation in a micro channel with a cylindrical solid block and liquid jet from a micro nozzle

  13. Numerical study on drop formation through a micro nozzle

    International Nuclear Information System (INIS)

    Kim, Sung Il; Son, Gi Hun

    2005-01-01

    The drop ejection process from a micro nozzle is investigated by numerically solving the conservation equations for mass and momentum. The liquid-gas interface is tracked by a level set method which is extended for two-fluid flows with irregular solid boundaries. Based on the numerical results, the liquid jet breaking and droplet formation behavior is found to depend strongly on the pulse type of forcing pressure and the contact angle at the gas-liquid-solid interline. The negative pressure forcing can be used to control the formation of satelite droplets. Also, various nozzle shapes are tested to investigate their effect on droplet formation

  14. Numerical study of a confined slot impinging jet with nanofluids

    Directory of Open Access Journals (Sweden)

    Manca Oronzio

    2011-01-01

    Full Text Available Abstract Background Heat transfer enhancement technology concerns with the aim of developing more efficient systems to satisfy the increasing demands of many applications in the fields of automotive, aerospace, electronic and process industry. A solution for obtaining efficient cooling systems is represented by the use of confined or unconfined impinging jets. Moreover, the possibility of increasing the thermal performances of the working fluids can be taken into account, and the introduction of nanoparticles in a base fluid can be considered. Results In this article, a numerical investigation on confined impinging slot jet working with a mixture of water and Al2O3 nanoparticles is described. The flow is turbulent and a constant temperature is applied on the impinging. A single-phase model approach has been adopted. Different geometric ratios, particle volume concentrations and Reynolds number have been considered to study the behavior of the system in terms of average and local Nusselt number, convective heat transfer coefficient and required pumping power profiles, temperature fields and stream function contours. Conclusions The dimensionless stream function contours show that the intensity and size of the vortex structures depend on the confining effects, given by H/W ratio, Reynolds number and particle concentrations. Furthermore, for increasing concentrations, nanofluids realize increasing fluid bulk temperature, as a result of the elevated thermal conductivity of mixtures. The local Nusselt number profiles show the highest values at the stagnation point, and the lowest at the end of the heated plate. The average Nusselt number increases for increasing particle concentrations and Reynolds numbers; moreover, the highest values are observed for H/W = 10, and a maximum increase of 18% is detected at a concentration equal to 6%. The required pumping power as well as Reynolds number increases and particle concentrations grow, which is almost 4

  15. Disturbances in Body Ownership in Schizophrenia: Evidence from the Rubber Hand Illusion and Case Study of a Spontaneous Out-of-Body Experience

    OpenAIRE

    Thakkar, Katharine N.; Nichols, Heathman S.; McIntosh, Lindsey G.; Park, Sohee

    2011-01-01

    Background A weakened sense of self may contribute to psychotic experiences. Body ownership, one component of self-awareness, can be studied with the rubber hand illusion (RHI). Watching a rubber hand being stroked while one's unseen hand is stroked synchronously can lead to a sense of ownership over the rubber hand, a shift in perceived position of the real hand, and a limb-specific drop in stimulated hand temperature. We aimed to assess the RHI in schizophrenia using quantifiable measures: ...

  16. Hand Anatomy

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy Bones Joints Muscles Nerves Vessels Tendons Anatomy The upper extremity is ...

  17. Promoting a Hand Hygiene Program Using Social Media: An Observational Study.

    Science.gov (United States)

    Pan, Sung-Ching; Sheng, Wang-Huei; Tien, Kuei-Lien; Chien, Kuang-Tse; Chen, Yee-Chun; Chang, Shawn-Chwen

    2016-01-01

    Hand hygiene is an important component in infection control to protect patient safety and reduce health care-associated infection. Our aim was to evaluate the efficacy of different social media on the promotion of a hand hygiene (HH) program. The observational study was conducted from May 5 to December 31, 2014, at a 2600-bed tertiary care hospital. A 3-minute video of an HH campaign in 8 languages was posted to YouTube. The Chinese version was promoted through three platforms: the hospital website, the hospital group email, and the Facebook site of a well-known Internet illustrator. The video traffic was analyzed via Google Analytics. HH compliance was measured in November 2013 and 2014. There were 5252 views of the video, mainly of the Chinese-language version (3509/5252, 66.81%). The NTUH website had 24,000 subscribers, and 151 of them viewed the video (connection rate was 151/24,000, 0.63%). There were 9967 users of the hospital email group and the connection rate was 0.91% (91/9967). The connection rate was 6.17% (807/13,080) from Facebook, significantly higher than the other 2 venues (both P<.001). HH compliance sustained from 83.7% (473/565) in 2013 to 86.7% (589/679) in 2014 (P=.13) among all HCWs. Facebook had the highest connection rate in the HH video campaign. The use of novel social media such as Facebook should be considered for future programs that promote hand hygiene and other healthy behaviors.

  18. Appendicular bone mass and knee and hand osteoarthritis in Japanese women: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Moji Kazuhiko

    2002-10-01

    Full Text Available Abstract Background It has been reported that there is an inverse association between osteoarthritis (OA and osteoporosis. However, the relationship of bone mass to OA in a Japanese population whose rates of OA are different from Caucasians remains uncertain. Methods We studied the association of appendicular bone mineral density (second metacarpal; mBMD and quantitative bone ultrasound (calcaneus; stiffness index with knee and hand OA among 567 Japanese community-dwelling women. Knee and hand radiographs were scored for OA using Kellgren-Lawrence (K/L scales. In addition, we evaluated the presence of osteophytes and of joint space narrowing. The hand joints were examined at the distal and proximal interphalangeal (DIP, PIP and first metacarpophalangeal/carpometacarpal (MCP/CMC joints. Results After adjusting for age and body mass index (BMI, stiffness index was significantly higher in women with K/L scale, grade 3 at CMC/MCP joint compared with those with no OA. Adjusted means of stiffness index and mBMD were significantly higher in women with definite osteophytes at the CMC/MCP joint compared to those without osteophytes, whereas there were no significant differences for knee, DIP and PIP joints. Stiffness index, but not mBMD, was higher in women with definite joint space narrowing at the CMC/MCP joint compared with those with no joint space narrowing. Conclusions Appendicular bone mass was increased with OA at the CMC/MCP joint, especially among women with osteophytes. Our findings suggest that the association of peripheral bone mass with OA for knee, DIP or PIP may be less clearcut in Japanese women than in other populations.

  19. Numerical study on transient local entropy generation in pulsating ...

    Indian Academy of Sciences (India)

    - soidal flow, step flow, and saw-down flow) and for varying periods. The flow and temperature fields are computed numerically with the help of the Fluent compu- tational fluid dynamics (CFD) code, and a computer program developed by us by.

  20. Numerical and Experimental Study of Electromagnetically Driven Vortical Flows

    NARCIS (Netherlands)

    Kenjeres, S.; Verdoold, J.; Tummers, M.J.; Hanjalic, K.; Kleijn, C.R.

    2009-01-01

    The paper reports on numerical and experimental investigations of electromagnetically driven vortical flows of an electrically conductive fluid in a generic setup. Two different configurations of permanent magnets are considered: a 3-magnet configuration in which the resulting Lorentz force is

  1. Biosensor enhancement using grooved micromixers: Part I, numerical studies

    Czech Academy of Sciences Publication Activity Database

    Lynn, Nicholas Scott; Homola, Jiří

    2015-01-01

    Roč. 87, č. 11 (2015), s. 5516-5523 ISSN 0003-2700 R&D Projects: GA ČR(CZ) GBP205/12/G118 Institutional support: RVO:67985882 Keywords : Numerical methods * Micromixers * Analytes Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 5.886, year: 2015

  2. Numerical study of agglomerate abrasion in a tumbling mixer

    NARCIS (Netherlands)

    Thanh Nguyen, [No Value; Willemsz, Tofan; Frijlink, Henderik; Maarschalk, Kees van der Voort

    2014-01-01

    A numerical simulation using the Discrete Element Method (DEM) was performed to investigate the phenomena concerning the abrasion and breakage of agglomerates in a diffusion powder mixer. Agglomerates were created by defining a single structure of particles with bonds of different strengths using

  3. The Pathology of Weaving and Production of the Hand-woven Carpets: Heriz Region Case Study

    Directory of Open Access Journals (Sweden)

    Sepideh Taravati Mahjoubi

    2017-04-01

    Full Text Available The carpet, as one of the most precious achievement of people, is a culture. The world’s recognition of Iranian carpet and its glorification originates from endeavor of people who have integrated artistic verve with mysterious attractions of national culture and arts. This study is descriptive-analytic. The data were collected through field research method and direct communication with people and workshops of drawing, weaving, and dyeing. In fact, the assessment tools were taken to the field, and data collection was completed by questioning, interview, observation, and shooting. Then, they were used for derivation, classification, and analysis. SPSS software also used to analyze collected data. . According to the result of this study, regarding the latest forecasts for Iranian hand-woven carpet industry, carpet exports will increase in the future. Therefore, it is better to consider the weaving and marketing of the carpet as a luxury product in order to achieve the profits maintaining the incentive of production in all units involved in the hand-woven carpet’s production and also to reduce poor quality carpets available in the market.

  4. A qualitative numerical study of high dimensional dynamical systems

    Science.gov (United States)

    Albers, David James

    Since Poincare, the father of modern mathematical dynamical systems, much effort has been exerted to achieve a qualitative understanding of the physical world via a qualitative understanding of the functions we use to model the physical world. In this thesis, we construct a numerical framework suitable for a qualitative, statistical study of dynamical systems using the space of artificial neural networks. We analyze the dynamics along intervals in parameter space, separating the set of neural networks into roughly four regions: the fixed point to the first bifurcation; the route to chaos; the chaotic region; and a transition region between chaos and finite-state neural networks. The study is primarily with respect to high-dimensional dynamical systems. We make the following general conclusions as the dimension of the dynamical system is increased: the probability of the first bifurcation being of type Neimark-Sacker is greater than ninety-percent; the most probable route to chaos is via a cascade of bifurcations of high-period periodic orbits, quasi-periodic orbits, and 2-tori; there exists an interval of parameter space such that hyperbolicity is violated on a countable, Lebesgue measure 0, "increasingly dense" subset; chaos is much more likely to persist with respect to parameter perturbation in the chaotic region of parameter space as the dimension is increased; moreover, as the number of positive Lyapunov exponents is increased, the likelihood that any significant portion of these positive exponents can be perturbed away decreases with increasing dimension. The maximum Kaplan-Yorke dimension and the maximum number of positive Lyapunov exponents increases linearly with dimension. The probability of a dynamical system being chaotic increases exponentially with dimension. The results with respect to the first bifurcation and the route to chaos comment on previous results of Newhouse, Ruelle, Takens, Broer, Chenciner, and Iooss. Moreover, results regarding the high

  5. [Hand osteoarthritis].

    Science.gov (United States)

    Šenolt, Ladislav

    Hand osteoarthritis (OA) is a common chronic disorder causing pain and limitation of mobility of affected joints. The prevalence of hand OA increases with age and more often affects females. Clinical signs obviously do not correlate with radiographic findings - symptomatic hand OA affects approximately 26 % of adult subjects, but radiographic changes can be found in up to two thirds of females and half of males older than 55 years.Disease course differ among individual patients. Hand OA is a heterogeneous disease. Nodal hand OA is the most common subtype affecting interphalangeal joints, thumb base OA affects first carpometacarpal joint. Erosive OA represents a specific subtype of hand OA, which is associated with joint inflammation, more pain, functional limitation and erosive findings on radiographs.Treatment of OA is limited. Analgesics and nonsteroidal anti-inflammatory drugs are the only agents reducing symptoms. New insights into the pathogenesis of disease should contribute to the development of novel effective treatment of hand OA.

  6. A retrospective outcomes study examining the effect of interactive metronome on hand function.

    Science.gov (United States)

    Shank, Tracy M; Harron, Wendy

    2015-01-01

    Interactive Metronome (IM, The Interactive Metronome Company, Sunrise, Florida, USA) is a computer-based modality marketed to rehabilitation professionals who want to improve outcomes in areas of coordination, motor skills, self-regulation behaviors, and cognitive skills. This retrospective study examined the efficacy of IM training on improving timing skills, hand function, and parental report of self-regulatory behaviors. Forty eight children with mixed motor and cognitive diagnoses completed an average of 14 one-hour training sessions over an average of 8.5 weeks in an outpatient setting. Each child was assessed before and after training with the Interactive Metronome Long Form Assessment, the Jebsen Taylor Test of Hand Function, and a parent questionnaire. All three measures improved with statistical significance despite participants having no direct skill training. These results suggest an intimate relationship between cognition and motor skills that has potential therapeutic value. Level 4, Retrospective Case Series. Copyright © 2015 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

  7. A Study of Hand Back Skin Texture Patterns for Personal Identification and Gender Classification

    Directory of Open Access Journals (Sweden)

    Jin Xie

    2012-06-01

    Full Text Available Human hand back skin texture (HBST is often consistent for a person and distinctive from person to person. In this paper, we study the HBST pattern recognition problem with applications to personal identification and gender classification. A specially designed system is developed to capture HBST images, and an HBST image database was established, which consists of 1,920 images from 80 persons (160 hands. An efficient texton learning based method is then presented to classify the HBST patterns. First, textons are learned in the space of filter bank responses from a set of training images using the -minimization based sparse representation (SR technique. Then, under the SR framework, we represent the feature vector at each pixel over the learned dictionary to construct a representation coefficient histogram. Finally, the coefficient histogram is used as skin texture feature for classification. Experiments on personal identification and gender classification are performed by using the established HBST database. The results show that HBST can be used to assist human identification and gender classification.

  8. A comparative study of single and multiple hand tasks using functional MRI

    International Nuclear Information System (INIS)

    Shin, Byung Suck; Lee, Ho Kyu; Park, Sung Tae; Kim, Dong Eun; Lee, Myung Jun; Choi, Choong Gon; Kim, Jae Kyun; Suh, Dae Chul; Lim, Tae Hwan

    1998-01-01

    The purpose of this study is to assess, using functional MRI and by comparing activated motor sensory areas, the independence of brain activation during single and alternative multiple hand tasks. The subjects were six healthy volunteers. Using at 1.5T Siemens system and single shot FID-EPI sequencing (T2 weighted image; TR/TE 0.96 msec/ 61msec, flip angle 90 deg, matrix size 96 x 128, slice thickness/gap 5 mm/0.8 mm, FOV 200 mm) and T1-weighted anatomic images, functional MRI was performed. The paradigm of motor tasks consisted of appositional finger movements; the first involved the separate use of the right, left, and both hands in sequence. Using cross-correlation method (threshold : 0.6) and fMRI analysis software (stimulate 5.0), functional images were obtained. The activated area of brain cortex, the number of pixel, the average percentage change in signal intensity, and correlation of the time-signal intensity curve in the activated motor area were analysed and compared between the two task groups. Statistical analysis involved the use of Wilcoxon signed-rank test. Brain activation did not differ according to whether the motor task was single or alternative. We therefore suggest that during multiple stimuli, the relevant functional area and neuronal column are activated independently. (author). 19 refs., 2 tabs., 3 figs

  9. a Numerical Study of Basic Coastal Upwelling Processes.

    Science.gov (United States)

    Li, Zhihong

    Available from UMI in association with The British Library. Two-dimensional (2-D) and three-dimensional (3 -D) numerical models with a second order turbulence closure are developed for the study of coastal upwelling processes. A logarithmic coordinate system is introduced to obtain increased resolution in the regions near the surface and bottom where high velocity shear occurs and in the upwelling zone where its width is confined to the coast. In the experiments performed in the 2-D model an ocean initially at rest is driven by a spatially uniform alongshore wind-stress. There is a development of an offshore flow in the surface layer and an onshore flow below the surface layer. In the wind-stress direction there is a development of a coastal surface jet. The neglect of the alongshore pressure gradient leads to the intensification of the jet, and the concentration of the onshore flow in an over-developed Ekman layer yielding an unrealistic deepening of a bottom mixed layer. When bathymetric variations are introduced, some modifications in the dynamics of upwelling are observed. On the shelf region there is another upwelling zone and isotherms are interested with the bottom topography. When an alongshore pressure gradient is added externally into the model, the strength of the coastal jet decreases and a coastal undercurrent exists at greater depth. In addition the return onshore flow is largely independent of depth and the deepening of the bottom mixed layer disappears. In the experiments performed in the 3-D model a wind-stress with limited domain is used. Coastally trapped waves are generated and propagate along the coastline leading to a development of an alongshore pressure gradient, which has a significant effect on upwelling. The evolution of the alongshore flow, vertical velocity and the temperature is determined by both remote and local wind due to the propagation of waves. As the integration proceeds, the flow pattern becomes remarkably 3-dimensional

  10. Semi Active Control of Civil Structures, Analytical and Numerical Studies

    Science.gov (United States)

    Kerboua, M.; Benguediab, M.; Megnounif, A.; Benrahou, K. H.; Kaoulala, F.

    numerical example of the parallel R-L piezoelectric vibration shunt control simulated with MATLAB® is presented. An analytical study of the resistor-inductor (R-L) passive piezoelectric vibration shunt control of a cantilever beam was undertaken. The modal and strain analyses were performed by varying the material properties and geometric configurations of the piezoelectric transducer in relation to the structure in order to maximize the mechanical strain produced in the piezoelectric transducer.

  11. A numerical study of bulk evaporation and condensation problem

    International Nuclear Information System (INIS)

    Ding, Z.; Anghaie, S.

    1996-01-01

    A numerical model is developed to simulate the dynamic behavior of bulk evaporation and condensation process in an encapsulated container with internal heat generation at micro-gravity level. Thermal performance of a multi-phase system with internal heat generation is investigated. The numerical simulation yields the evolution of the bulk liquid-vapor phase change process. This includes the evolution of the liquid-vapor interface, the formation and development of the liquid film covering the side wall surface, the temperature distribution and the convection flow field. An example of such systems is a phase change nuclear fuel element which was first introduced by Ding and Anghaie with application in high temperature space nuclear power and propulsion systems

  12. Numerical study on hygroscopic material drying in packed bed

    Directory of Open Access Journals (Sweden)

    M. Stakić

    2011-06-01

    Full Text Available The paper addresses numerical simulation for the case of convective drying of hygroscopic material in a packed bed, analyzing agreement between the simulated and the corresponding experimental results. In the simulation model of unsteady simultaneous one-dimensional heat and mass transfer between gas phase and dried material, it is assumed that the gas-solid interface is at thermodynamic equilibrium, while the drying rate of the specific product is calculated by applying the concept of a "drying coefficient". Model validation was done on the basis of the experimental data obtained with potato cubes. The obtained drying kinetics, both experimental and numerical, show that higher gas (drying agent velocities (flow-rates, as well as lower equivalent grain diameters, induce faster drying. This effect is more pronounced for deeper beds, because of the larger amount of wet material to be dried using the same drying agent capacity.

  13. Experimental study of a shear wall with numerous small openings

    International Nuclear Information System (INIS)

    Sotomura, K.; Murazumi, Y.; Yoshizaki, S.; Ezaki, T.

    1981-01-01

    Many small openings for piping and ducts are usually required in the shear walls for PWR nuclear power plant. It is generally believed that such openings oadversely affect the strength and stiffness of shear walls. However, little information is available concerning the behavior of walls with numerous small openings. Therefore, tests using wall specimens and an analysis using an FEM program were carried out to investigate this behavior. Main findings are as follows: 1) The ultimate strength of a shear wall with numerous small openings may be obtained by using the effective area at the critical cross section of the shear wall. 2) Shear walls with openings can be restored to the same shear strength and stiffness as shear walls without openings by diagonal reinforcement. (orig./HP)

  14. A Study of Enhanced, Higher Order Boussinesq-Type Equations and Their Numerical Modelling

    DEFF Research Database (Denmark)

    Banijamali, Babak

    model is designated for the solution of higher-order Boussinesq-type equations, formulated in terms of the horizontal velocity at an arbitrary depth vector. Various discretisation techniques and grid definitions have been considered in this endeavour, undertaking a detailed analysis of the selected......This project has encompassed efforts in two separate veins: on the one hand, the acquiring of highly accurate model equations of the Boussinesq-type, and on the other hand, the theoretical and practical work in implementing such equations in the form of conventional numerical models, with obvious...... potential for applications to the realm of numerical modelling in coastal engineering. The derivation and analysis of several forms of higher-order in dispersion and non-linearity Boussinesq-type equations have been undertaken, obtaining and investigating the properties of a new and generalised class...

  15. Experimental, theoretical, and numerical studies of small scale combustion

    Science.gov (United States)

    Xu, Bo

    Recently, the demand increased for the development of microdevices such as microsatellites, microaerial vehicles, micro reactors, and micro power generators. To meet those demands the biggest challenge is obtaining stable and complete combustion at relatively small scale. To gain a fundamental understanding of small scale combustion in this thesis, thermal and kinetic coupling between the gas phase and the structure at meso and micro scales were theoretically, experimentally, and numerically studied; new stabilization and instability phenomena were identified; and new theories for the dynamic mechanisms of small scale combustion were developed. The reduction of thermal inertia at small scale significantly reduces the response time of the wall and leads to a strong flame-wall coupling and extension of burning limits. Mesoscale flame propagation and extinction in small quartz tubes were theoretically, experimentally and numerically studied. It was found that wall-flame interaction in mesoscale combustion led to two different flame regimes, a heat-loss dominant fast flame regime and a wall-flame coupling slow flame regime. The nonlinear transition between the two flame regimes was strongly dependent on the channel width and flow velocity. It is concluded that the existence of multiple flame regimes is an inherent phenomenon in mesoscale combustion. In addition, all practical combustors have variable channel width in the direction of flame propagation. Quasi-steady and unsteady propagations of methane and propane-air premixed flames in a mesoscale divergent channel were investigated experimentally and theoretically. The emphasis was the impact of variable cross-section area and the flame-wall coupling on the flame transition between different regimes and the onset of flame instability. For the first time, spinning flames were experimentally observed for both lean and rich methane and propane-air mixtures in a broad range of equivalence ratios. An effective Lewis number

  16. Theoretical and numerical study of an optimum design algorithm

    International Nuclear Information System (INIS)

    Destuynder, Philippe.

    1976-08-01

    This work can be separated into two main parts. First, the behavior of the solution of an elliptic variational equation is analyzed when the domain is submitted to a small perturbation. The case of inequations is also considered. Secondly the previous results are used for deriving an optimum design algorithm. This algorithm was suggested by the center-method proposed by Huard. Numerical results show the superiority of the method on other different optimization techniques [fr

  17. Key issues review: numerical studies of turbulence in stars

    Science.gov (United States)

    Arnett, W. David; Meakin, Casey

    2016-10-01

    Three major problems of single-star astrophysics are convection, magnetic fields and rotation. Numerical simulations of convection in stars now have sufficient resolution to be truly turbulent, with effective Reynolds numbers of \\text{Re}>{{10}4} , and some turbulent boundary layers have been resolved. Implications of these developments are discussed for stellar structure, evolution and explosion as supernovae. Methods for three-dimensional (3D) simulations of stars are compared and discussed for 3D atmospheres, solar rotation, core-collapse and stellar boundary layers. Reynolds-averaged Navier-Stokes (RANS) analysis of the numerical simulations has been shown to provide a novel and quantitative estimate of resolution errors. Present treatments of stellar boundaries require revision, even for early burning stages (e.g. for mixing regions during He-burning). As stellar core-collapse is approached, asymmetry and fluctuations grow, rendering spherically symmetric models of progenitors more unrealistic. Numerical resolution of several different types of three-dimensional (3D) stellar simulations are compared; it is suggested that core-collapse simulations may be under-resolved. The Rayleigh-Taylor instability in explosions has a deep connection to convection, for which the abundance structure in supernova remnants may provide evidence.

  18. Numerical studies of pair creation in counterpropagating laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Ruf, Matthias

    2009-05-27

    Pair creation from vacuum induced by electromagnetic fields is probably one of the most intriguing phenomena in physics. If the fields are sufficiently strong, the QED vacuum become unstable. Due to the remarkable progress in laser technology during recent years an experimental investigation of pair creation by pure laser light is coming into reach. The focus of this thesis is on pair creation in counterpropagating laser beams. The pair creation probability is calculated employing the numerically obtained solutions of the Dirac equation. This numerical ansatz has the capability of calculating the momentum distribution of the created pairs in a single propagation, for pure time dependent field configurations. Furthermore, it allows to take the magnetic component of the laser fields into account, which is usually neglected. The latter strongly affects the creation process at high laser frequency. The involved numerical calculations are rather time consuming, therefore the second project of this thesis was to develop a highly efficient code for solving relativistic quantum mechanical problems. This is accomplished by adopting the split-operator method to the Klein-Gordon equation. Here the possibility arises to use parallel computing. However the corresponding spin-statistics becomes crucial in the case of pair creation, demonstrated in several examples. (orig.)

  19. Experimental and Numerical Study of FRP Encased Composite Concrete Columns

    Directory of Open Access Journals (Sweden)

    Mohsen Ishaghian

    2017-02-01

    Full Text Available A new type of composite column is presented and assessed through experimental testing and numerical modeling. The objective of this research is to investigate design options for a composite column without the use of ferrous materials. This is to avoid the current problem of deterioration of concrete due to expansion of rusting reinforcement members. Such a target can be achieved by replacing the steel reinforcement of concrete columns with pultruded I-shape glass FRP structural sections. The composite column utilizes a glass FRP tube that surrounds a pultruded I-section glass FRP, which is subsequently filled with concrete. The GFRP tube acts as a stay-in-place form in addition to providing confinement to the concrete. A total of four composite columns were tested under monotonic axial loading. The experimental ultimate capacity of each of the tested composite column was compared to the predicted numerical capacity using ANSYS program. The comparison showed that the predicted numerical values were in good agreement with the experimental ones.

  20. Numerical studies of pair creation in counterpropagating laser fields

    International Nuclear Information System (INIS)

    Ruf, Matthias

    2009-01-01

    Pair creation from vacuum induced by electromagnetic fields is probably one of the most intriguing phenomena in physics. If the fields are sufficiently strong, the QED vacuum become unstable. Due to the remarkable progress in laser technology during recent years an experimental investigation of pair creation by pure laser light is coming into reach. The focus of this thesis is on pair creation in counterpropagating laser beams. The pair creation probability is calculated employing the numerically obtained solutions of the Dirac equation. This numerical ansatz has the capability of calculating the momentum distribution of the created pairs in a single propagation, for pure time dependent field configurations. Furthermore, it allows to take the magnetic component of the laser fields into account, which is usually neglected. The latter strongly affects the creation process at high laser frequency. The involved numerical calculations are rather time consuming, therefore the second project of this thesis was to develop a highly efficient code for solving relativistic quantum mechanical problems. This is accomplished by adopting the split-operator method to the Klein-Gordon equation. Here the possibility arises to use parallel computing. However the corresponding spin-statistics becomes crucial in the case of pair creation, demonstrated in several examples. (orig.)

  1. Experimental and numerical study of a flapping tidal stream generator

    Science.gov (United States)

    Kim, Jihoon; Le, Tuyen Quang; Ko, Jin Hwan; Sitorus, Patar Ebenezer; Tambunan, Indra Hartarto; Kang, Taesam

    2017-11-01

    The tidal stream turbine is one of the systems that extract kinetic energy from tidal stream, and there are several types of the tidal stream turbine depending on its operating motion. In this research, we conduct experimental and consecutive numerical analyses of a flapping tidal stream generator with a dual configuration flappers. An experimental analysis of a small-scale prototype is conducted in a towing tank, and a numerical analysis is conducted using two-dimensional computational fluid dynamics simulations with an in-house code. Through an experimental analysis conducted while varying these factors, a high applied load and a high input arm angle were found to be advantageous. In consecutive numerical investigations with the kinematics selected from the experiments, it was found that a rear-swing flapper contributes to the total amount of power more than a front-swing flapper with a distance of two times the chord length and with a 90-degree phase difference between the two. This research was a part of the project titled `R&D center for underwater construction robotics', funded by the Ministry of Oceans and Fisheries(MOF), Korea Institute of Marine Science & Technology Promotion(KIMST,PJT200539), and Pohang City in Korea.

  2. Numerical study of turbulent flow in a rectangular T-junction

    Science.gov (United States)

    Georgiou, Michail; Papalexandris, Miltiadis V.

    2017-06-01

    In this paper, we report on a numerical study of the interaction and merging of a turbulent crossflow with an incoming turbulent jet in a T-junction with rectangular cross section. Our study is based on wall-resolved and experimentally validated large eddy simulations. The bulk Reynolds number of the crossflow is 15 000. Further, we consider cases with two different momentum ratios, namely, MR = 2 and MR = 0.5. In the presentation of the results, we elaborate on the main features of the flow, namely, the shear layers that emanate from the corners of the entry of the jet, the large recirculation bubble downstream the incoming jet, and the mixing process beyond the reattachment point. For validation purposes, we compare our simulations with existing experimental data. This comparison shows a good agreement between our numerical predictions and the measurements. First- and second-order statistics of the flow are also presented and analyzed in detail. Our simulations reveal two features of the flow that have not been reported before in studies of T-junctions. The first one is a secondary small-scale recirculation region between the entry of the jet and the large recirculation bubble. The second one is the negative turbulent kinetic energy production that occurs in the recirculation bubble and close to the reattachment of the flow. The analysis of our results further reveals that just across the entry of the jet, the boundary layer in the wall opposite to the jet experiences a favourable pressure gradient due to a Venturi effect induced by the incoming jet. In turn, this favourable pressure gradient contributes to the local relaminarization of the flow. On the other hand, the boundary layer downstream the recirculation bubble experiences an adverse pressure gradient. In both cases, a significant deviation from the universal law of the wall is confirmed.

  3. Cultural adaptation of the Michigan Hand Outcomes Questionnaire in patients with Carpal Tunnel Syndrome: A Turkish version study

    Directory of Open Access Journals (Sweden)

    Ilker Ilhanli

    2015-03-01

    Full Text Available Objective: Cultural adaptations of the questionnaires are important for easy use. We aimed to assess the reliability and validity of the Turkish Version of the Michigan Hand Outcomes Questionnaire in patients with Carpal Tunnel Syndrome. Methods: To assess test-retest reliability, the Turkish “Michigan Hand Outcomes Questionnaire” and “Disabilities of Arm, Shoulder and Hand” questionnaires were answered by patients and controls and were repeated a week later. For testing internal consistency, the Cronbach's alpha test was used. For testing validity, correlations between the subscales of the “Michigan Hand Outcomes Questionnaire” and “Disabilities of Arm, Shoulder and Hand” questionnaire were measured in patient groups. One hundred patients with idiopathic Carpal Tunnel Syndrome and 50 healthy participants were included in the study. Results: In test-retest reliability, intraclass correlations of the subscales of the “Michigan Hand Outcomes Questionnaire” were high. Cronbach's alphas were found to be high in all subscales. There was no significant correlation between asthetics and pain scales. We found significant differences between patients and controls regarding all subscales of the “Michigan Hand Outcomes Questionnaire”. Correlations between subscales of the “Michigan Hand Outcomes Questionnaire” and “Disabilities of Arm, Shoulder and Hand” questionnaire were significant. We found no difference between one-hand effected and two-hand effected patients, in terms of the “Michigan Hand Outcomes Questionnaire”, “Disabilities of Arm, Shoulder and Hand” questionnaire Function/Symptom and Work average scores. Conclusion: This study showed that the Turkish version of the “Michigan Hand Outcomes Questionnaire” is reliable and valid and can be used in Turkish patients with Carpal Tunnel Syndrome because it is comprehensible and practicable

  4. A Study on Immersion and Presence of a Portable Hand Haptic System for Immersive Virtual Reality

    OpenAIRE

    Kim, Mingyu; Jeon, Changyu; Kim, Jinmo

    2017-01-01

    This paper proposes a portable hand haptic system using Leap Motion as a haptic interface that can be used in various virtual reality (VR) applications. The proposed hand haptic system was designed as an Arduino-based sensor architecture to enable a variety of tactile senses at low cost, and is also equipped with a portable wristband. As a haptic system designed for tactile feedback, the proposed system first identifies the left and right hands and then sends tactile senses (vibration and hea...

  5. Numerical simulation and sensitivity study of a severe hailstorm in northeast Spain

    Science.gov (United States)

    García-Ortega, E.; Fita, L.; Romero, R.; López, L.; Ramis, C.; Sánchez, J. L.

    2007-02-01

    During the afternoon of August 16th 2003 a severe hail event occurred in the town of Alcañiz in the Ebro Valley (Spain). This storm brought with it intense rain and hail precipitation that caused severe floods, damaged cars and street furniture. A diagnosis, using data from ECMWF, showed the presence of a mesolow at surface level centered over the Northeast of Spain, carrying winds from the Mediterranean Sea towards the Central Ebro Valley. At medium and high levels, a trough, whose axis extended over the Northwest of the Iberian Peninsula, moved eastwards preceded at 500 hPa by a thermal trough that caused increasing instability before the arrival of the geopotential trough. A numerical study of this event has been carried out using the MM5 model with a double aim. On the one hand, it attempts to check whether or not the simulation reproduces the storm in Alcañiz. On the other hand, it carries out a sensitivity experiment in order to evaluate the contribution of two specific factors: topography and solar radiation. Compared with radar data, the control simulation reproduces the region affected by the storm reasonably well. The suppression of topography and/or solar radiation substantially modifies the surface mesolow and the spatial distribution of the precipitation. Neither of these factors, considered independently, reproduces the precipitation caused by the storm in Alcañiz. However, the results illustrate the importance of the synergic effect of these two factors on the spatial localization of the storm and on the intensity of the precipitation registered.

  6. A feasibility study of hand kinematics for EVA analysis using magnetic resonance imaging

    Science.gov (United States)

    Dickenson, Rueben D.; Lorenz, Christine H.; Peterson, Steven W.; Strauss, Alvin M.; Main, John A.

    1992-01-01

    A new method of analyzing the kinematics of joint motion is developed. Magnetic Resonance Imaging (MRI) offers several distinct advantages. Past methods of studying anatomic joint motion have usually centered on four approaches. These methods are x-ray projection, goniometric linkage analysis, sonic digitization, and landmark measurement of photogrammetry. Of these four, only x-ray is applicable for in vivo studies. The remaining three methods utilize other types of projections of inter-joint measurements, which can cause various types of error. MRI offers accuracy in measurement due to its tomographic nature (as opposed to projection) without the problems associated with x-ray dosage. Once the data acquisition of MR images was complete, the images were processed using a 3D volume rendering workstation. The metacarpalphalangeal (MCP) joint of the left index finger was selected and reconstructed into a three-dimensional graphic display. From the reconstructed volumetric images, measurements of the angles of movement of the applicable bones were obtained and processed by analyzing the screw motion of the MCP joint. Landmark positions were chosen at distinctive locations of the joint at fixed image threshold intensity levels to ensure repeatability. The primarily two dimensional planar motion of this joint was then studied using a method of constructing coordinate systems using three (or more) points. A transformation matrix based on a world coordinate system described the location and orientation of a local target coordinate system. Future research involving volume rendering of MRI data focusing on the internal kinematics of the hand's individual ligaments, cartilage, tendons, etc. will follow. Its findings will show the applicability of MRI to joint kinematics for gaining further knowledge of the hand-glove (power assisted) design for extravehicular activity (EVA).

  7. Magnetic resonance imaging and ultrasonography in diagnosing arthritis of the hand joints: a comparative study

    International Nuclear Information System (INIS)

    Ciechomska, A.; Bachta, A.; Tlustochowicz, W.; Serafin-Krol, M.; Jakubowski, W.; Andrysiak, R.; Krolicki, L.

    2005-01-01

    Assessment of joint inflammation in clinical practice is based on physical examination. Imaging modalities which allow soft tissues to be visualized may be helpful in making the assessment impartial and to evaluate the severity of inflammation. The aim of the study was to compare magnetic resonance imaging (MRI) and ultrasonography (USG) findings in visualizing joint inflammation of the hand. The study comprised 113 patients with chronic arthritis, of whom 88 patients had rheumatoid arthritis (RA) and 25 arthritis of etiology unconnected with RA. MRI of the hand was performed in 98 patients and USG of the hand in 86 patients. Sixty-four patients underwent both USG and MRI. In the USG examinations a linear, high-frequency transducer of 5-9 MHz and a Color Doppler option (CD-USG) were used. MRI was performed with a 1.5 T unit in the SE sequences T1, T1 with fat saturation, and before and after Gd-DTPA injection. Assessed joints included the wrist joints, etacarpophalangeal joints, and proximal and distal interphalangeal joints (1921 joints in total). Tenosynovitis of the flexors and extensors was also evaluated. MRI showed inflammation in 277 joints (16.6%) of 66 patients. The mean number of inflamed joints found using MRI was 2.8 ± 2.9. US visualized synovitis in a larger number of joints (350, 23.9%) in 63 patients. The mean number of inflamed joints found by USG was 4.1 ± 4.0. Increased blood flow on CD-USG was seen in 202 joints (13.8%) of 72 patients. The difference between RA and non-RA patients as visible on MRI and USG were statistically significant. There were correlations in showing joint inflammation between MRI and USG (τ = 0.64; p < 0.00001) and between CD-USG and MRI (τ = 0.44; p < 0.00001) and concordance in showing flexor tendon sheath inflammation. MRI and USG both show inflammation of the joints. The concordance between the methods in showing joint inflammation depends upon analyzing the features of inflammation. Availability and the

  8. Numerical study on the thermal performance of a ventilated facade with PCM

    International Nuclear Information System (INIS)

    Gracia, Alvaro de; Navarro, Lidia; Castell, Albert; Cabeza, Luisa F.

    2013-01-01

    A new type of ventilated facade (VF) with macro-encapsulated phase change material (PCM) in its air cavity is presented in this paper. Two identical house-like cubicles located in Puigverd de Lleida (Spain) were monitored during 2012, and in one of them, the VF with PCM was implemented in the south wall. The versatility of the facade allows the system to reduce both heating and cooling loads. During winter, the PCM increases the heat storage capacity of the system exposed to solar radiation and during summer the system can be used as a cold storage unit or as a night free cooling device. From the experimental winter campaign, important net electrical energy savings were registered due to the use of the VF. On the other hand, no net energy savings were achieved during summer due to excessive use of mechanical ventilation. In this paper, an own developed numerical model, based on finite control volume approach, was validated against experimental data and it is used to select the operational schedule of both solidification and melting processes in order to achieve net electrical energy savings. During the mild summer period the system presents a net energy supply of 2.49 MJ/day. This value would be increased by 61.6% if a wooden structure would have been used instead of the current metallic structure. Moreover, the high hysteresis of the PCM limits strongly the potential of the system in supplying cooling during the severe summer period. -- Highlights: • Numerical study of the thermal performance of a ventilated facade with PCM. • The study considers cooling purposes. • Operational schedule and use of fans during solidification of PCM optimization. • Net energy supply of 2.49 MJ/day during mild summer from the ventilated facade. • Storage efficiency would maximize with more mechanical ventilation during less time

  9. Exploring the gap between hand washing knowledge and practices in Bangladesh: a cross-sectional comparative study.

    Science.gov (United States)

    Rabbi, Sifat E; Dey, Nepal C

    2013-01-30

    Hand washing is considered as one of the most effective hygiene promotion activities for public health in developing countries. This study compared hand washing knowledge and practices in BRAC's water; sanitation and hygiene (WASH) programme areas over time. This study is a cross-sectional comparative study between baseline (2006), midline (2009) and end-line (2011) surveys in 50 sub-districts from the first phase of the programme. Thirty thousand households from 50 sub-districts were selected in two steps: i) 30 villages were selected from each sub-district by cluster sampling, and ii) 20 households were chosen systematically from each village. The matched households were considered (26,404 in each survey) for analysis. Data were collected from households through face-to-face interview using a pre-tested questionnaire. Respondents were the adult female members of the same households, who had knowledge of day-to-day household activities related to water, sanitation and hygiene. A gap between perception and practice of proper hand washing practices with soap was identified in the study areas. Hand washing practice with soap before eating was much lower than after defecation. In baseline data, 8% reported to wash their hands with soap which significantly increased to 22% in end line. Hand washing knowledge and practices before cooking food, before serving food and while handling babies is considerably limited than other critical times. A multivariate analysis shows that socio-economic factors including education of household head and respondent, water availability and access to media have strong positive association with hand washing with soap. Gap between knowledge and practice still persists in hand washing practices. Long term and extensive initiatives can aware people about the effectiveness of hand washing.

  10. Exploring the gap between hand washing knowledge and practices in Bangladesh: a cross-sectional comparative study

    Directory of Open Access Journals (Sweden)

    Rabbi Sifat E

    2013-01-01

    Full Text Available Abstract Background Hand washing is considered as one of the most effective hygiene promotion activities for public health in developing countries. This study compared hand washing knowledge and practices in BRAC’s water; sanitation and hygiene (WASH programme areas over time. Methods This study is a cross-sectional comparative study between baseline (2006, midline (2009 and end-line (2011 surveys in 50 sub-districts from the first phase of the programme. Thirty thousand households from 50 sub-districts were selected in two steps: i 30 villages were selected from each sub-district by cluster sampling, and ii 20 households were chosen systematically from each village. The matched households were considered (26,404 in each survey for analysis. Data were collected from households through face-to-face interview using a pre-tested questionnaire. Respondents were the adult female members of the same households, who had knowledge of day-to-day household activities related to water, sanitation and hygiene. Results A gap between perception and practice of proper hand washing practices with soap was identified in the study areas. Hand washing practice with soap before eating was much lower than after defecation. In baseline data, 8% reported to wash their hands with soap which significantly increased to 22% in end line. Hand washing knowledge and practices before cooking food, before serving food and while handling babies is considerably limited than other critical times. A multivariate analysis shows that socio-economic factors including education of household head and respondent, water availability and access to media have strong positive association with hand washing with soap. Conclusion Gap between knowledge and practice still persists in hand washing practices. Long term and extensive initiatives can aware people about the effectiveness of hand washing.

  11. Functional and Psychosocial Outcomes of Hand Transplantation Compared with Prosthetic Fitting in Below-Elbow Amputees: A Multicenter Cohort Study.

    Directory of Open Access Journals (Sweden)

    Stefan Salminger

    Full Text Available Hand-transplantation and improvements in the field of prostheses opened new frontiers in restoring hand function in below-elbow amputees. Both concepts aim at restoring reliable hand function, however, the indications, advantages and limitations for each treatment must be carefully considered depending on level and extent of amputation. Here we report our findings of a multi-center cohort study comparing hand function and quality-of-life of people with transplanted versus prosthetic hands.Hand function in amputees with either transplant or prostheses was tested with Action Research Arm Test (ARAT, Southampton Hand Assessment Procedure (SHAP and the Disabilities of the Arm, Shoulder and Hand measure (DASH. Quality-of-life was compared with the Short-Form 36 (SF-36.Transplanted patients (n = 5 achieved a mean ARAT score of 40.86 ± 8.07 and an average SHAP score of 75.00 ± 11.06. Prosthetic patients (n = 7 achieved a mean ARAT score of 39.00 ± 3.61 and an average SHAP score of 75.43 ± 10.81. There was no significant difference between transplanted and prosthetic hands in ARAT, SHAP or DASH. While quality-of-life metrics were equivocal for four scales of the SF-36, transplanted patients reported significantly higher scores in "role-physical" (p = 0.006, "vitality" (p = 0.008, "role-emotional" (p = 0.035 and "mental-health" (p = 0.003.The indications for hand transplantation or prosthetic fitting in below-elbow amputees require careful consideration. As functional outcomes were not significantly different between groups, patient's best interests and the route of least harm should guide treatment. Due to the immunosuppressive side-effects, the indication for allotransplantation must still be restrictive, the best being bilateral amputees.

  12. An fMRI study of the neural basis hand postures specific to tool use. Presidential award proceedings

    International Nuclear Information System (INIS)

    Ohgami, Yuko; Uchida, Nobuko; Matsuo, Kayako; Nakai, Toshiharu

    2007-01-01

    Patients with apraxia are often unable to mimic the use of a tool, even when it is presented visually. Such mimicking involves various cognitive and motor processes, including the visual perception of a tool and the manipulation of imagined tools. Although previous studies reported the involvement of several brain areas, including the left inferior parietal lobule, in such tool-use action, the details of each process have not been well understood. To clarify the neural basis of the process involved in forming hand postures for using tools, we used functional magnetic resonance imaging (fMRI) in normal volunteers to investigate brain activation while they formed hand postures for tool manipulation. Three conditions were evaluated in separate block-designed fMRI series, formation of hand posture (A) using a tool, (B) imitating such a hand posture, and (C) to imitate the shape of a tool. Subjects formed their right hand in a manner specified according to the task conditions. Hand posturing for condition (A) induced activation in the left inferior frontal gyrus (BA 45), left inferior parietal lobule (BA 40), and the premotor area compared with the imitative posturing of condition (B). Activation in these areas might be related to processes shared by tool-use pantomime. On the other hand, comparison between conditions (A) and (C) demonstrated activation in the right superior parietal lobule (BA 7). This activation may reflect spatial regulation, in which the subject was prepared to hold and manipulate the tool. Formation of static hand postures to prepare for tool use may employ a neural network shared by various tool-use actions, such as pantomime. In addition, forming hand postures may require close coordination between the tool and hand. (author)

  13. Cathodal Transcranial Direct Current Stimulation Improves Focal Hand Dystonia in Musicians: A Two-Case Study

    Directory of Open Access Journals (Sweden)

    Sara Marceglia

    2017-09-01

    Full Text Available Focal hand dystonia (FHD in musicians is a movement disorder causing abnormal movements and irregularities in playing. Since weak electrical currents applied to the brain induce persistent excitability changes in humans, cathodal tDCS was proposed as a possible non-invasive approach for modulating cortical excitability in patients with FHD. However, the optimal targets and modalities have still to be determined. In this pilot study, we delivered cathodal (2 mA, anodal (2 mA and sham tDCS over the motor areas bilaterally for 20 min daily for five consecutive days in two musicians with FHD. After cathodal tDCS, both patients reported a sensation of general wellness and improved symptoms of FHD. In conclusion, our pilot results suggest that cathodal tDCS delivered bilaterally over motor-premotor (M-PM cortex for 5 consecutive days may be effective in improving symptoms in FHD.

  14. Tingling/numbness in the hands of computer users: neurophysiological findings from the NUDATA study

    DEFF Research Database (Denmark)

    Overgaard, E.; Brandt, L. P.; Ellemann, K.

    2004-01-01

    OBJECTIVES: To investigate whether tingling/numbness of the hands and fingers among computer users is associated with elevated vibration threshold as a sign of early nerve compression. METHODS: Within the Danish NUDATA study, vibratory sensory testing with monitoring of the digital vibration...... once a week or daily within the last 3 months. Participants with more than slight muscular pain or disorders of the neck and upper extremities, excessive alcohol consumption, previous injuries of the upper extremities, or concurrent medical diseases were excluded. The two groups had a similar amount...... of work with mouse, keyboard, and computer. RESULTS: Seven of the 20 cases (35%) had elevated vibration thresholds, compared with 3 of the 20 controls (15%); this difference was not statistically significant (chi2=2.13, P=0.14). Compared with controls, cases had increased perception threshold for all...

  15. Left-Handed Metamaterials Studies and their Application to Accelerator Physics

    CERN Document Server

    Antipov, Sergey P; Liu Wan Ming; Power, John G

    2005-01-01

    Recently, there has been a growing interest in applying artificial materials, known as Left-Handed Metamaterials (LHM), to accelerator physics. These materials have both negative permittivity and permeability and therefore possess several unusual properties: the index of refraction is negative and the direction of the group velocity is antiparallel to the direction of the phase velocity (along k). These properties lead to a reverse Cherenkov effect, which has potential beam diagnostic applications, in addition to accelerator applications. Several LHM devices with different configurations are being experimentally and theoretically studied at Argonne. In this paper, we describe permittivity and permeability retrieval techniques that we have developed and applied to these devices. We have also investigated the possibility of building a Cherenkov detector based on LHM and propose an experiment to observe the reverse radiation generated by an electron beam passing through a LHM. The potential advantage of a LHM de...

  16. Numerical studies of the stochastic Korteweg-de Vries equation

    International Nuclear Information System (INIS)

    Lin Guang; Grinberg, Leopold; Karniadakis, George Em

    2006-01-01

    We present numerical solutions of the stochastic Korteweg-de Vries equation for three cases corresponding to additive time-dependent noise, multiplicative space-dependent noise and a combination of the two. We employ polynomial chaos for discretization in random space, and discontinuous Galerkin and finite difference for discretization in physical space. The accuracy of the stochastic solutions is investigated by comparing the first two moments against analytical and Monte Carlo simulation results. Of particular interest is the interplay of spatial discretization error with the stochastic approximation error, which is examined for different orders of spatial and stochastic approximation

  17. Flow Structures and Efficiency of Swimming Fish school: Numerical Study

    Science.gov (United States)

    Yatagai, Yuzuru; Hattori, Yuji

    2013-11-01

    The flow structure and energy-saving mechanism in fish school is numerically investigated by using the volume penalization method. We calculate the various patterns of configuration of fishes and investigate the relation between spatial arrangement and the performance of fish. It is found that the down-stream fish gains a hydrodynamic advantage from the upstream wake shed by the upstream fish. The most efficient configuration is that the downstream fish is placed in the wake. It reduces the drag force of the downstream fish in comparison with that in solo swimming.

  18. Delay in medical attention to hand eczema: a follow-up study

    DEFF Research Database (Denmark)

    Hald, M; Agner, T; Blands, J

    2009-01-01

    BACKGROUND: Hand eczema often runs a chronic course but early medical intervention may be assumed to improve the prognosis. OBJECTIVES: To follow patients with hand eczema for 6 months after seeing a dermatologist to investigate if delay in medical attention would impair the prognosis. METHODS...... was associated with longer delay before medical attention....

  19. Knowledge, attitudes and behaviour in everyday life with chronic hand eczema - a qualitative study

    DEFF Research Database (Denmark)

    Mollerup, A; Johansen, J D; Thing, Lone Friis

    2013-01-01

    Chronic hand eczema is a common disease which may impact quality of life and have occupational and social consequences. Self-management is pivotal, both in handling acute eruptions and avoiding relapses. However, little is known about how people with hand eczema self-manage and integrate their di...

  20. Numerical Study of Frequency-dependent Seismoelectric Coupling in Partially-saturated Porous Media

    Directory of Open Access Journals (Sweden)

    Djuraev Ulugbek

    2017-01-01

    Full Text Available The seismoelectric phenomenon associated with propagation of seismic waves in fluid-saturated porous media has been studied for many decades. The method has a great potential to monitor subsurface fluid saturation changes associated with production of hydrocarbons. Frequency of the seismic source has a significant impact on measurement of the seismoelectric effects. In this paper, the effects of seismic wave frequency and water saturation on the seismoelectric response of a partially-saturated porous media is studied numerically. The conversion of seismic wave to electromagnetic wave was modelled by extending the theoretically developed seismoelectric coupling coefficient equation. We assumed constant values of pore radius and zeta-potential of 80 micrometers and 48 microvolts, respectively. Our calculations of the coupling coefficient were conducted at various water saturation values in the frequency range of 10 kHz to 150 kHz. The results show that the seismoelectric coupling is frequency-dependent and decreases exponentially when frequency increases. Similar trend is seen when water saturation is varied at different frequencies. However, when water saturation is less than about 0.6, the effect of frequency is significant. On the other hand, when the water saturation is greater than 0.6, the coupling coefficient shows monotonous trend when water saturation is increased at constant frequency.

  1. Numerical study of thermal test of a cask of transportation for radioactive material

    International Nuclear Information System (INIS)

    Vieira, Tiago A.S.; Santos, André A.C. dos; Vidal, Guilherme A.M.; Silva Junior, Geraldo E.

    2017-01-01

    In this study numerical simulations of a transport cask for radioactive material were made and the numerical results were compared with experimental results of tests carried out in two different opportunities. A mesh study was also made regarding the previously designed geometry of the same cask, in order to evaluate its impact in relation to the stability of numerical results for this type of problem. The comparison of the numerical and experimental results allowed to evaluate the need to plan and carry out a new test in order to validate the CFD codes used in the numerical simulations

  2. Cortical bone drilling: An experimental and numerical study.

    Science.gov (United States)

    Alam, Khurshid; Bahadur, Issam M; Ahmed, Naseer

    2014-12-16

    Bone drilling is a common surgical procedure in orthopedics, dental and neurosurgeries. In conventional bone drilling process, the surgeon exerts a considerable amount of pressure to penetrate the drill into the bone tissue. Controlled penetration of drill in the bone is necessary for safe and efficient drilling. Development of a validated Finite Element (FE) model of cortical bone drilling. Drilling experiments were conducted on bovine cortical bone. The FE model of the bone drilling was based on mechanical properties obtained from literature data and additionally conducted microindentation tests on the cortical bone. The magnitude of stress in bone was found to decrease exponentially away from the lips of the drill in simulations. Feed rate was found to be the main influential factor affecting the force and torque in the numerical simulations and experiments. The drilling thrust force and torque were found to be unaffected by the drilling speed in numerical simulations. Simulated forces and torques were compared with experimental results for similar drilling conditions and were found in good agreement.CONCLUSIONS: FE schemes may be successfully applied to model complex kinematics of bone drilling process.

  3. Numerical and experimental study of capillary forces in trapezoid microgrooves

    Science.gov (United States)

    Sheu, Tsung-Sheng; Ding, Pei-Pei; Chen, Ping-Hei

    1999-08-01

    The evaporation of thin liquid films is of significant importance in a wide variety of heat transfer problems. The vaporization process of thin liquid films in a trapezoid microgroove channel was investigated both numerically and experimentally. In order to predict the wetted axial length of capillary flow in a trapezoid microgroove, the nonlinear governing equation was solved numerically and a simplified algebraic equation was also derived. The parameters include the input heat flux, tilt angle of grooved surface, thermophysical properties of working fluid, and geometric parameters of microgrooves. In order to investigate the effect of geometric parameters of microgrooves on the wetted axial length, a series of either trapezoid or triangular microgrooves was machined on the surface of copper test devices for experimental measurements. Measurements were conducted using either methanol or ethanol as working fluid at four different tilt angles of grooved surface and four applied input heat flux values. The wetted axial length was measured using microscopy observation. The predicted results of the algebraic equation are found to be in reasonable agreement with the experimental data, especially for cases of higher tilt angle or higher heat flux. Besides, using microgrooves of triangular shape or using methanol as working fluid can increase the wetted axial length of microgrooves.

  4. Numerical study of particle capture efficiency in fibrous filter

    Directory of Open Access Journals (Sweden)

    Fan Jianhua

    2017-01-01

    Full Text Available Numerical simulations are performed for transport and deposition of particles over a fixed obstacle in a fluid flow. The effect of particle size and Stokes number on the particle capture efficiency is investigated using two methods. The first one is one-way coupling combining Lattice Boltzmann (LB method with Lagrangian point-like approach. The second one is two-way coupling based on the coupling between Lattice Boltzmann method and discrete element (DE method, which consider the particle influence on the fluid. Then the single fiber collection efficiency characterized by Stokes number (St are simulated by LB-DE methods. Results show that two-way coupling method is more appropriate in our case for particles larger than 8 μm. A good agreement has also been observed between our simulation results and existing correlations for single fiber collection efficiency. The numerical simulations presented in this work are useful to understand the particle transport and deposition and to predict the capture efficiency.

  5. Numerical study of wave disturbance in liquid cooling film

    Directory of Open Access Journals (Sweden)

    S.R. Shine

    2013-06-01

    Full Text Available Transient numerical simulations are carried out to investigate the liquid-gas interface characteristics associated with liquid film cooling flows. A two-dimensional axisymmetric multi-phase numerical model using finite volume formulation is developed. The model has been validated against available experimental data for liquid-film cooling flows inside tubes. The model has been used to predict the interface characteristics for a variety of imposed parameters and momentum flux ratios under cold flow conditions wherein both the coolant and mainstream are maintained at the same temperature. Disturbance waves are observed at the liquid-gas interface for coolant flows above a critical value and after a finite distance from the inlet. The distance toward the wave inception point increased with the increase of momentum flux ratio. However, at higher momentum flux ratios, the properties of the disturbance waves did not vary significantly. The parameters related to the liquid-gas interface waves, namely, wave velocity, frequency, amplitude and wave length have been analyzed in detail. Analysis indicates that the liquid entrainment is due to the shearing of the disturbance wave crest.

  6. Numerical study of unsteady viscous flow past oscillating airfoil

    Energy Technology Data Exchange (ETDEWEB)

    Jin Yan; Yuan Xin [Tsinghua Univ., Dept. of Thermal Engineering, Beijing (China)

    2001-07-01

    Accurate simulation of the dynamic stall of an oscillating airfoil is of major importance to wing and wind turbine blade design. However, dynamic stall is complicated and influenced by many factors, such as geometry shape of the airfoil, reduced frequency, etc. The difficulties of simulation are both mathematical (numerical method) and physical (turbulence model). The present paper has introduced a new numerical method (new LU-type scheme and fourth-order higher resolution MUSCL TVD scheme) and q-{omega} turbulence modelling to calculate the unsteady flowfields of an oscillating NACA0015 airfoil. The test targets include attached flow, light-stall and deep-stall of the airfoil. The calculated results for attached flow and light-stall are in good agreement with those of experiments. The calculated results for deep-stall also show improvement, especially during the downstroke of the oscillation. However, there is still a significant difference between the results of calculation and experiment in the hysteresis curves of the drag coefficient. One reason is that the q-{omega} turbulence model still has limitations. Another is that the drag coefficient is difficult to measure and the experiments are not reliable. (Author)

  7. Numerical Study on Mass Transfer of a Vapor Bubble Rising in Very High Viscous Fluid

    Directory of Open Access Journals (Sweden)

    T. Kunugi

    2014-09-01

    Full Text Available This study focused on a bubble rising behavior in a molten glass because it is important to improve the efficiency of removal of bubbles from the molten glass. On the other hand, it is expected that some gas species which exists in a bubble are transferred into the molten glass through the bubble interface, i.e., the mass transfer, subsequently, it may cause a bubble contraction in the molten glass. In this paper, in order to understand the bubble rising behavior with its contraction caused by the mass transfer through the bubble interface in the very high viscous fluid such as the molten glass, a bubble contraction model has been developed. The direct numerical simulations based on the MARS (Multi-interface Advection and Reconstruction Solver coupled with the mass transfer equation and the bubble contraction model regarding the mass transfer from the rising bubble in very high viscous fluid have been performed. Here, the working fluids were water vapor as the gas species and the molten glass as the very high viscous fluid. Also, the jump conditions at the bubble interface for the mass transfer were examined. Furthermore, the influence of the bubble contraction for the bubble rising compared to that in the water as a normal viscous fluid was investigated. From the result of the numerical simulations, it was found that the bubble rising behavior was strongly affected not only by the viscosity of the working fluid but also by the bubble contraction due to the mass transfer through the bubble interface.

  8. "In Situ Vascular Nerve Graft" for Restoration of Intrinsic Hand Function: An Anatomical Study.

    Science.gov (United States)

    Mozaffarian, Kamran; Zemoodeh, Hamid Reza; Zarenezhad, Mohammad; Owji, Mohammad

    2018-06-01

    In combined high median and ulnar nerve injury, transfer of the posterior interosseous nerve branches to the motor branch of the ulnar nerve (MUN) is previously described in order to restore intrinsic hand function. In this operation a segment of sural nerve graft is required to close the gap between the donor and recipient nerves. However the thenar muscles are not innervated by this nerve transfer. The aim of the present study was to evaluate whether the superficial radial nerve (SRN) can be used as an "in situ vascular nerve graft" to connect the donor nerves to the MUN and the motor branch of median nerve (MMN) at the same time in order to address all denervated intrinsic and thenar muscles. Twenty fresh male cadavers were dissected in order to evaluate the feasibility of this modification of technique. The size of nerve branches, the number of axons and the tension at repair site were evaluated. This nerve transfer was technically feasible in all specimens. There was no significant size mismatch between the donor and recipient nerves Conclusions: The possible advantages of this modification include innervation of both median and ulnar nerve innervated intrinsic muscles, preservation of vascularity of the nerve graft which might accelerate the nerve regeneration, avoidance of leg incision and therefore the possibility of performing surgery under regional instead of general anesthesia. Briefly, this novel technique is a viable option which can be used instead of conventional nerve graft in some brachial plexus or combined high median and ulnar nerve injuries when restoration of intrinsic hand function by transfer of posterior interosseous nerve branches is attempted.

  9. Intensification of transesterification via sonication numerical simulation and sensitivity study

    International Nuclear Information System (INIS)

    Janajreh, Isam; ElSamad, Tala; Noorul Hussain, Mohammed

    2017-01-01

    Highlights: • 3D numerical simulation of transesterification is accomplished. • A non-isothermal, reactive Navier–stokes was carried out. • Conventional and sonicated process was compared as far as reaction kinetics and yield. • Higher kinetic rates are achieved at lower molar ratios in sonicated process. • It validates feasibility of numerical simulation for transesterification assessment. - Abstract: Transesterification is known as slow reaction that can take over several hours to complete. The process involves two immiscible reactants to produce the biodiesel and the byproduct glycerol. Biodiesel commercialization has always been hindered by the long process times of the transesterification reaction. Catalyzing the process and increasing the agitation rate is the mode of intensifying the process additional to the increase of the molar ratio, temperature, circulation that all penalize the overall process metrics. Finding shorter path by reducing the reaction into a few minutes and ensures high quality biodiesel, in economically viable way is coming along with sonication. This drastic reduction moves the technology from the slow batch process into the high throughput continuous process. In a practical sense this means a huge optimization for the biodiesel production process which opens pathways for faster, voluminous and cheaper production. The mechanism of sonication assisted reaction is explained by the creation of microbubbles which increases the interfacial surface reaction areas and the presence of high localized temperature and turbulence as these microbubbles implode. As a result the reaction kinetics of sonicated transesterification as inferred by several authors is much faster. The aim of this work is to implement the inferred rates in a high fidelity numerical reactive flow simulation model while considering the reactor geometry. It is based on Navier–Stokes equations coupled with energy equation for non-isothermal flow and the transport

  10. Altered brain functions in HIV positive patients free of HIV- associated neurocognitive disorders: A MRI study during unilateral hand movements

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2015-03-01

    Full Text Available This paper aimed to investigate the brain activity of human immunodeficiency virus (HIV positive patients with normal cognition during unilateral hand movement and whether highly active antiretroviral therapy (HAART could affect the brain function. Functional magnetic resonance imaging (fMRI was performed for 60 HIV positive (HIV+ subjects and −42 healthy age-matched right-handed control subjects. Each subject was evaluated by the neuropsychological test and examined with fMRI during left and right hand movement tasks. HIV+ subjects showed greater activation in anterior cingulum, precuneus, occipital lobes, ipsilateral postcentral gyrus and contralateral cerebellum compared with control group during right hand movement task. However, during left hand movement no statistically significant difference was detected between these two groups. HAART medication for HIV+ subjects lowered the increased activity to normal level. Meanwhile patients receiving the regimen of zidovudine, lamivudine and efavirenz showed lower activity at bilateral caudate and ipsilateral inferior frontal gyrus in comparison with subjects receiving other HAART regimens. Therefore, HIV+ subjects demonstrated brain asymmetry in motor cortex, with increased activity present during right hand movement but absent during left hand movement. HAART proves effective in HIV+ subjects even with normal cognition and the specific regimen of HAART could prevent cerebral abnormal functions. Meanwhile, this study validates that during motor tasks, fMRI can detect the brain signal changes prior to the occurrences of other HIV- associated dysfunctions.

  11. Hand hygiene in emergency medical services.

    Science.gov (United States)

    Teter, Jonathan; Millin, Michael G; Bissell, Rick

    2015-01-01

    Hospital-acquired infections (HAIs) affect millions of patients annually (World Health Organization. Guidelines on Hand Hygiene in Healthcare. Geneva: WHO Press; 2009). Hand hygiene compliance of clinical staff has been identified by numerous studies as a major contributing factor to HAIs around the world. Infection control and hand hygiene in the prehospital environment can also contribute to patient harm and spread of infections. Emergency medical services (EMS) practitioners are not monitored as closely as hospital personnel in terms of hand hygiene training and compliance. Their ever-changing work environment is less favorable to traditional hospital-based aseptic techniques and education. This study aimed to determine the current state of hand hygiene practices among EMS providers and to provide recommendations for improving practices in the emergency health services environment. This study was a prospective, observational prevalence study and survey, conducted over a 2-month period. We selected participants from visits to three selected hospital emergency departments in the mid-Atlantic region. There were two data components to the study: a participant survey and hand swabs for pathogenic cultures. This study recruited a total sample of 62 participants. Overall, the study revealed that a significant number of EMS providers (77%) have a heavy bacterial load on their hands after patient care. All levels of providers had a similar distribution of bacterial load. Survey results revealed that few providers perform hand hygiene before (34%) or in between patients (24%), as recommended by the Centers for Disease Control and Prevention guidelines. This study demonstrates that EMS providers are potential vectors of microorganisms if proper hand hygiene is not performed properly. Since EMS providers treat a variety of patients and operate in a variety of environments, providers may be exposed to potentially pathogenic organisms, serving as vectors for the exposure of

  12. Gas leakage rate through reinforced concrete shear walls: Numerical study

    International Nuclear Information System (INIS)

    Wang Ting; Hutchinson, Tara C.

    2005-01-01

    Unlined reinforced concrete shear walls are often used as 'tertiary boundaries' in the United States Department of Energy (DOE) to house dangerous gases. An unanticipated event, such as an earthquake, may cause gases stored inside the walls to disperse into the environment resulting in excess pollution. To address this concern, in this paper, a methodology to numerically predict the gas leakage rate through these shear walls under lateral loading conditions is proposed. This methodology involves finite element and flow rate analysis. Strain distributions are obtained from the finite element analysis, and then used to simulate the crack characteristics on the concrete specimen. The flow rate through the damaged concrete specimen is then estimated using flow rate formulas available from the literature. Results from an experimental specimen are used to evaluate the methodology, and particularly its robustness in the flow rate estimation

  13. Numerical study of a novel dew point evaporative cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Riangvilaikul, B.; Kumar, S. [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120 (Thailand)

    2010-11-15

    Dew point evaporative cooling system is an alternative to vapor compression air conditioning system for sensible cooling of ventilation air. This paper presents the theoretical performance of a novel dew point evaporative cooling system operating under various inlet air conditions (covering dry, moderate and humid climate) and influence of major operating parameters (namely, velocity, system dimension and the ratio of working air to intake air). A model of the dew point evaporative cooling system has been developed to simulate the heat and mass transfer processes. The outlet air conditions and system effectiveness predicted by the model using numerical method for known inlet parameters have been validated with experimental findings and with recent literature. The model was used to optimize the system parameters and to investigate the system effectiveness operating under various inlet air conditions. (author)

  14. Experimental and numerical study of micro deep drawing

    Directory of Open Access Journals (Sweden)

    Luo Liang

    2015-01-01

    Full Text Available Micro forming is a key technology for an industrial miniaturisation trend, and micro deep drawing (MDD is a typical micro forming method. It has great advantages comparing to other micro manufacturing methods, such as net forming ability, mass production potential, high product quality and complex 3D metal products fabrication capacity. Meanwhile, it is facing difficulties, for example the so-called size effects, once scaled down to micro scale. To investigate and to solve the problems in MDD, a combined micro blanking-drawing machine is employed and an explicit-implicit micro deep drawing model with a voronoi blank model is developed. Through heat treatment different grain sizes can be obtained, which affect material's properties and, consequently, the drawing process parameters, as well as produced cups' quality. Further, a voronoi model can provide detailed material information in simulation, and numerical simulation results are in accordance with experimental results.

  15. Numerical study on aerodynamic heat of hypersonic flight

    Directory of Open Access Journals (Sweden)

    Huang Haiming

    2016-01-01

    Full Text Available Accurate prediction of the shock wave has a significant effect on the development of space transportation vehicle or exploration missions. Taking Lobb sphere as the example, the aerodynamic heat of hypersonic flight in different Mach numbers is simulated by the finite volume method. Chemical reactions and non-equilibrium heat are taken into account in this paper, where convective flux of the space term adopts the Roe format, and discretization of the time term is achieved by backward Euler algorithm. The numerical results reveal that thick mesh can lead to accurate prediction, and the thickness of the shock wave decreases as grid number increases. Furthermore, most of kinetic energy converts into internal energy crossing the shock wave.

  16. Numerical study of some operating characteristics for argon induction plasmas

    International Nuclear Information System (INIS)

    Ebihara, K.

    1978-01-01

    Some operating characteristics of argon induction plasmas at atmospheric pressure were obtained numerically by using magnetohydrodynamic equations. From these characteristics we can estimate the general dependency of plasma temperatures on operating conditions for induction plasmas. Calculated relationships between the sustaining electric field strength at the plasma surface and the electric power input show the existence of a minimum value of the field strength, the reason for which is revealed by detailed investigation of the calculated radial temperature distributions. Further, it was found that the minimum increases almost linearly with increasing frequency. In addition, characteristics of the Poynting vector and heat conduction loss at the plasma surface were obtained. Some characteristics obtained here give practical information on the electromagnetic field which is necessary to maintain the steady plasmas

  17. Contact sensitisation in hand eczema patients-relation to subdiagnosis, severity and quality of life: a multi-centre study

    DEFF Research Database (Denmark)

    Agner, T.; Andersen, K.E.; Brandao, F.M.

    2009-01-01

    Background Contact sensitisation has been identified as a factor associated with poor prognosis for patients with hand eczema. Objectives To study implications of contact sensitisation with respect to severity, quality of life (QoL) and subdiagnosis of hand eczema. Methods The study was performed...... and presence of contact sensitisation were independent risk factors for increased severity as measured by Hand Eczema Severity Index. Furthermore, the severity of hand eczema increased by the number of contact sensitisations detected (P = 0.023). High age and personal history of atopic eczema were independent...... risk factors for low QoL, as measured by Dermatology Life Quality Index, and atopic eczema as well as allergic contact dermatitis as subdiagnosis was associated with increased sick leave. Conclusion Diagnostic subgroups were not found to be related to specific allergens. Contact sensitisation was found...

  18. Experimental and numerical studies of high-velocity impact fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Kipp, M.E.; Grady, D.E.; Swegle, J.W.

    1993-08-01

    Developments are reported in both experimental and numerical capabilities for characterizing the debris spray produced in penetration events. We have performed a series of high-velocity experiments specifically designed to examine the fragmentation of the projectile during impact. High-strength, well-characterized steel spheres (6.35 mm diameter) were launched with a two-stage light-gas gun to velocities in the range of 3 to 5 km/s. Normal impact with PMMA plates, thicknesses of 0.6 to 11 mm, applied impulsive loads of various amplitudes and durations to the steel sphere. Multiple flash radiography diagnostics and recovery techniques were used to assess size, velocity, trajectory and statistics of the impact-induced fragment debris. Damage modes to the primary target plate (plastic) and to a secondary target plate (aluminum) were also evaluated. Dynamic fragmentation theories, based on energy-balance principles, were used to evaluate local material deformation and fracture state information from CTH, a three-dimensional Eulerian solid dynamics shock wave propagation code. The local fragment characterization of the material defines a weighted fragment size distribution, and the sum of these distributions provides a composite particle size distribution for the steel sphere. The calculated axial and radial velocity changes agree well with experimental data, and the calculated fragment sizes are in qualitative agreement with the radiographic data. A secondary effort involved the experimental and computational analyses of normal and oblique copper ball impacts on steel target plates. High-resolution radiography and witness plate diagnostics provided impact motion and statistical fragment size data. CTH simulations were performed to test computational models and numerical methods.

  19. A numerical study of granular dam-break flow

    Science.gov (United States)

    Pophet, N.; Rébillout, L.; Ozeren, Y.; Altinakar, M.

    2017-12-01

    Accurate prediction of granular flow behavior is essential to optimize mitigation measures for hazardous natural granular flows such as landslides, debris flows and tailings-dam break flows. So far, most successful models for these types of flows focus on either pure granular flows or flows of saturated grain-fluid mixtures by employing a constant friction model or more complex rheological models. These saturated models often produce non-physical result when they are applied to simulate flows of partially saturated mixtures. Therefore, more advanced models are needed. A numerical model was developed for granular flow employing a constant friction and μ(I) rheology (Jop et al., J. Fluid Mech. 2005) coupled with a groundwater flow model for seepage flow. The granular flow is simulated by solving a mixture model using Finite Volume Method (FVM). The Volume-of-Fluid (VOF) technique is used to capture the free surface motion. The constant friction and μ(I) rheological models are incorporated in the mixture model. The seepage flow is modeled by solving Richards equation. A framework is developed to couple these two solvers in OpenFOAM. The model was validated and tested by reproducing laboratory experiments of partially and fully channelized dam-break flows of dry and initially saturated granular material. To obtain appropriate parameters for rheological models, a series of simulations with different sets of rheological parameters is performed. The simulation results obtained from constant friction and μ(I) rheological models are compared with laboratory experiments for granular free surface interface, front position and velocity field during the flows. The numerical predictions indicate that the proposed model is promising in predicting dynamics of the flow and deposition process. The proposed model may provide more reliable insight than the previous assumed saturated mixture model, when saturated and partially saturated portions of granular mixture co-exist.

  20. Influencing factors on hand hygiene behavior of nursing students based on theory of planned behavior: A descriptive survey study.

    Science.gov (United States)

    Jeong, Sun Young; Kim, Kyung Mi

    2016-01-01

    Hand hygiene is the single most important measure to prevent transmission of infection, but the compliance rate of healthcare workers is relatively low. This study was conducted to identify the knowledge, beliefs, behavior, and affecting factors about hand hygiene among nursing students. A descriptive survey study. The study was carried out in two South Korean nursing schools. A total 208 nursing students participated in this study. Questionnaires were used to collect data. The percentage of correct answers in the survey section concerning hand hygiene knowledge was 68.1%. No significant difference in the knowledge, behavioral beliefs, normative beliefs, or control beliefs data was found related to general characteristics. Behavioral beliefs correlated with normative beliefs (r=.25, phand hygiene behavior (r=.17, p=.017), and control beliefs correlated with hand hygiene behavior (r=.18, p=.010). The results suggest that knowledge is not enough to change the beliefs related to hand hygiene; positive behavioral beliefs and strong control beliefs are also needed to increase hand hygiene compliance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Contact sensitisation in hand eczema patients-relation to subdiagnosis, severity and quality of life: a multi-centre study

    DEFF Research Database (Denmark)

    Agner, Tove; Andersen, Klaus Ejner; Brandao, Francisco M

    2009-01-01

    BACKGROUND: Contact sensitisation has been identified as a factor associated with poor prognosis for patients with hand eczema. OBJECTIVES: To study implications of contact sensitisation with respect to severity, quality of life (QoL) and subdiagnosis of hand eczema. METHODS: The study was perfor......BACKGROUND: Contact sensitisation has been identified as a factor associated with poor prognosis for patients with hand eczema. OBJECTIVES: To study implications of contact sensitisation with respect to severity, quality of life (QoL) and subdiagnosis of hand eczema. METHODS: The study...... eczema and presence of contact sensitisation were independent risk factors for increased severity as measured by Hand Eczema Severity Index. Furthermore, the severity of hand eczema increased by the number of contact sensitisations detected (P = 0.023). High age and personal history of atopic eczema were...... independent risk factors for low QoL, as measured by Dermatology Life Quality Index, and atopic eczema as well as allergic contact dermatitis as subdiagnosis was associated with increased sick leave. CONCLUSION: Diagnostic subgroups were not found to be related to specific allergens. Contact sensitisation...

  2. Studies of Limits on Uncontrolled Heavy Ion Beam Losses for Allowing Hands-On Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Reginald M. Ronningen; Igor Remec

    2010-09-11

    Dose rates from accelerator components activated by 1 W/m beam losses are obtained semiempirically for a 1 GeV proton beam and by use of Monte Carlo transport codes for the proton beam and for 777 MeV/u 3He, 500 MeV/u 48Ca, 86Kr, 136Xe, and 400 MeV/u 238U ions. The dose rate obtained by the semi-empirical method, 0.99 mSv/h (99 mrem/h) at 30 cm, 4 h after 100 d irradiation by a 1-GeV proton beam, is consistent with studies at several accelerator facilities and with adopted hands-on maintenance dose rate limits. Monte Carlo simulations verify this result for protons and extend studies to heavy ion beam losses in drift-tube linac and superconducting linac accelerating structures. The studies indicate that the 1 W/m limit imposed on uncontrolled beam losses for high-energy proton beams might be relaxed for heavy ion beams. These studies further suggest that using the ratio of neutrons produced by a heavy ion beam to neutrons produced by a proton beam along with the dose rate from the proton beam (for thin-target scenarios) should allow an estimate of the dose rates expected from heavy ion beam losses.

  3. A Study on Immersion and Presence of a Portable Hand Haptic System for Immersive Virtual Reality.

    Science.gov (United States)

    Kim, Mingyu; Jeon, Changyu; Kim, Jinmo

    2017-05-17

    This paper proposes a portable hand haptic system using Leap Motion as a haptic interface that can be used in various virtual reality (VR) applications. The proposed hand haptic system was designed as an Arduino-based sensor architecture to enable a variety of tactile senses at low cost, and is also equipped with a portable wristband. As a haptic system designed for tactile feedback, the proposed system first identifies the left and right hands and then sends tactile senses (vibration and heat) to each fingertip (thumb and index finger). It is incorporated into a wearable band-type system, making its use easy and convenient. Next, hand motion is accurately captured using the sensor of the hand tracking system and is used for virtual object control, thus achieving interaction that enhances immersion. A VR application was designed with the purpose of testing the immersion and presence aspects of the proposed system. Lastly, technical and statistical tests were carried out to assess whether the proposed haptic system can provide a new immersive presence to users. According to the results of the presence questionnaire and the simulator sickness questionnaire, we confirmed that the proposed hand haptic system, in comparison to the existing interaction that uses only the hand tracking system, provided greater presence and a more immersive environment in the virtual reality.

  4. A Study on Immersion and Presence of a Portable Hand Haptic System for Immersive Virtual Reality

    Science.gov (United States)

    Kim, Mingyu; Jeon, Changyu; Kim, Jinmo

    2017-01-01

    This paper proposes a portable hand haptic system using Leap Motion as a haptic interface that can be used in various virtual reality (VR) applications. The proposed hand haptic system was designed as an Arduino-based sensor architecture to enable a variety of tactile senses at low cost, and is also equipped with a portable wristband. As a haptic system designed for tactile feedback, the proposed system first identifies the left and right hands and then sends tactile senses (vibration and heat) to each fingertip (thumb and index finger). It is incorporated into a wearable band-type system, making its use easy and convenient. Next, hand motion is accurately captured using the sensor of the hand tracking system and is used for virtual object control, thus achieving interaction that enhances immersion. A VR application was designed with the purpose of testing the immersion and presence aspects of the proposed system. Lastly, technical and statistical tests were carried out to assess whether the proposed haptic system can provide a new immersive presence to users. According to the results of the presence questionnaire and the simulator sickness questionnaire, we confirmed that the proposed hand haptic system, in comparison to the existing interaction that uses only the hand tracking system, provided greater presence and a more immersive environment in the virtual reality. PMID:28513545

  5. The role and utilisation of public health evaluations in Europe: a case study of national hand hygiene campaigns

    Science.gov (United States)

    2014-01-01

    Background Evaluations are essential to judge the success of public health programmes. In Europe, the proportion of public health programmes that undergo evaluation remains unclear. The European Centre for Disease Prevention and Control sought to determine the frequency of evaluations amongst European national public health programmes by using national hand hygiene campaigns as an example of intervention. Methods A cohort of all national hand hygiene campaigns initiated between 2000 and 2012 was utilised for the analysis. The aim was to collect information about evaluations of hand hygiene campaigns and their frequency. The survey was sent to nominated contact points for healthcare-associated infection surveillance in European Union and European Economic Area Member States. Results Thirty-six hand hygiene campaigns in 20 countries were performed between 2000 and 2012. Of these, 50% had undergone an evaluation and 55% of those utilised the WHO hand hygiene intervention self-assessment tool. Evaluations utilised a variety of methodologies and indicators in assessing changes in hand hygiene behaviours pre and post intervention. Of the 50% of campaigns that were not evaluated, two thirds reported that both human and financial resource constraints posed significant barriers for the evaluation. Conclusion The study identified an upward trend in the number of hand hygiene campaigns implemented in Europe. It is likely that the availability of the internationally-accepted evaluation methodology developed by the WHO contributed to the evaluation of more hand hygiene campaigns in Europe. Despite this rise, hand hygiene campaigns appear to be under-evaluated. The development of simple, programme-specific, standardised guidelines, evaluation indicators and other evidence-based public health materials could help promote evaluations across all areas of public health. PMID:24507086

  6. Hand eczema, atopic dermatitis and filaggrin mutations in adult Danes: a registry-based study assessing risk of disability pension.

    Science.gov (United States)

    Heede, Nina G; Thuesen, Betina H; Thyssen, Jacob P; Linneberg, Allan; Szecsi, Pal B; Stender, Steen; Menné, Torkil; Johansen, Jeanne D

    2017-08-01

    Atopic dermatitis and hand eczema often impair the ability of people to work. Only a few studies have investigated whether individuals with loss-of-function filaggrin gene (FLG) mutations, who often have severe and early onset of dermatitis, experience occupational consequences. To investigate the personal consequences of having atopic dermatitis and/or hand eczema and FLG mutations. Adult Danes from the general population (n = 3247) and patients with atopic dermatitis and/or hand eczema (n = 496) were genotyped for common FLG mutations, and completed a questionnaire about skin symptoms and hand eczema. Socioeconomic variables, including disability pension, and information on work in risk occupations were retrieved from national registries. The reasons for granting disability pension were unknown. Disability pension was associated with hand eczema in the general population, especially among individuals with a history of atopic dermatitis. Moreover, self-reported hand eczema and atopic dermatitis were associated with particularly high risk of disability pension among FLG mutation carriers [odds ratio (OR) 4.02 and 95% confidence interval (CI): 1.15-14.11; and OR 6.01 and 95%CI: 2.37-15.34, respectively]. Furthermore, 60% of the FLG mutation carriers with atopic dermatitis who developed hand eczema had experienced symptoms before adulthood. In the general population, self-reported hand eczema and atopic dermatitis, particularly in individuals with a genetically impaired skin barrier, were associated with disability pension, suggesting that FLG mutations carriers with a history of atopic dermatitis and hand eczema could benefit from early attention with respect to choice of occupation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Numerical study on shear resisting mechanism for corroded RC box culverts

    International Nuclear Information System (INIS)

    Matsuo, Toyofumi; Matsumura, Takuro; Iwamori, Akiyuki

    2013-01-01

    This paper discusses the effects of reinforcing steel corrosion on the shear resisting mechanism of RC box culverts and the applicability of the material degradation model in a finite element method. First, in FEM analyses, loss of reinforcement section area and initial tension strain due to reinforcement corrosion, and deteriorated bond characteristics between reinforcement and concrete, were considered. Second, cyclic loading tests using full-scale corroded specimens were numerically analyzed. The analyzed crack patterns and load-displacement relationships up to the maximum load were observed to be in close agreement with the experiment results within the average corrosion ratio of 10% of primary reinforcement. The fact that corrosion cracks can importantly affect the progression of shear cracks and shear strength of RC beams was also found. On the other hand, we established that RC box culverts being statically indeterminate structures, sectional forces are redistributed after cracking damage, and local material deterioration has a minor effect on shear capacity. Furthermore, a parametric study was carried out for corroded RC box culverts using parameters such as size, steel corrosion location, and corrosion level. (author)

  8. A numerical study of the integral equations for the laser fields in free-electron lasers

    International Nuclear Information System (INIS)

    Yoo, J. G.; Park, S. H.; Jeong, Y. U.; Lee, B. C.; Rhee, Y. J.; Cho, S. O.

    2004-01-01

    The dynamics of the radiation fields in free-electron lasers is investigated on the basis of the integro-differential equations in the one-dimensional formulation. For simple cases we solved the integro-differential equations analytically and numerically to test our numerical procedures developed on the basis of the Filon method. The numerical results showed good agreement with the analytical solutions. To confirm the legitimacy of the numerical package, we carried out numerical studies on the inhomogeneous broadening effects, where no analytic solutions are available, due to the energy spread and the emittance of the electron beam.

  9. Dry powder segregation and flowability: Experimental and numerical studies

    Science.gov (United States)

    Ely, David R.

    Dry powder blending is a very important industrial and physical process used in the production of numerous pharmaceutical dosage forms such as tablets, capsules, and dry powder aerosols. Key aspects of this unit operation are process monitoring and control. Process control is particularly difficult due to the complexity of particle-particle interactions, which arise from the adhesion/cohesion characteristics of interfaces and morphological characteristics such as particle size, shape, and dispersity. The effects of such characteristics need to be understood in detail in order to correlate individual particle properties to bulk powder properties. The present dissertation numerically and experimentally quantifies the mixing process to rationalize particle-particle interactions. In particular, near infrared spectroscopy (NIRS) was used to non-invasively characterize in real-time the blending processes and thus investigate the dynamics of blending under different operating conditions. A novel image analysis technique was developed to quantify the scale of segregation from images obtained non-destructively via near infrared chemical imaging (NIR-CI). Although NIR-CI data acquisition times are too long for real-time data collection, NIR-CI has an advantage, in that it provides the spatial distribution of the drug. Therefore, NIRS and NIR-CI are complementary techniques for investigating the complex process of blending dry powders and assessing end-product quality. Additionally, the discrete element method was used to investigate the effect of powder cohesion on the packing fraction. Simulations indicated an exponential relationship between the random loose packing fraction and cohesive forces. Specifically, the packing fraction decreased asymptotically with increased ratio of cohesive force to particle weight. Thus, increasing this force ratio above a critical value has negligible impact on the packing fraction. Such result directly impacts the Hausner ratio flowability

  10. Dual-task performance involving hand dexterity and cognitive tasks and daily functioning in people with schizophrenia: a pilot study.

    Science.gov (United States)

    Lin, Keh-chung; Wu, Yi-fang; Chen, I-chen; Tsai, Pei-luen; Wu, Ching-yi; Chen, Chia-ling

    2015-01-01

    This study investigated separate and concurrent performance on cognitive and hand dexterity tasks and the relationship to daily functioning in 16 people with schizophrenia and 16 healthy control participants. Participants performed the Purdue Pegboard Test and the Serial Seven Subtraction Test under single- and dual-task conditions and completed two daily functioning evaluations. The hand dexterity of all participants declined in the dual-task condition, but the discrepancy between single-task and dual-task hand dexterity was greater in the schizophrenia group than in the control group (p.70, for all). The extent of discrepancy in hand dexterity was negatively correlated with daily functioning in the schizophrenia group (rs=-.3 to -.5, ps=.04-.26). Ability to perform dual tasks may be an indicator of daily functioning in people with schizophrenia. Use of dual-task training may be considered as a therapeutic activity with these clients. Copyright © 2015 by the American Occupational Therapy Association, Inc.

  11. Numerical study on small scale vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Parra-Santos Teresa

    2016-01-01

    Full Text Available The performance of a Vertical Axis Wind Turbine (VAWT is numerically analyzed. The set-up is Hdarrieus with three straight blades airfoils NACA attached to a rotating vertical shaft. The wind turbine has solidity equals to the unity operating with wind velocity of 7 m/s. Influence of pitch angle is tested to get design tendencies. 2D, transient, Navier Stokes equations are solved using the code Ansys-Fluent. Conservation equations were solved with a Third-Order MUSCL scheme using SIMPLE to couple pressure and velocity. More than six revolutions must be simulated to get the periodic behavior. Two models of turbulence have been contrasted Realizable k-epsilon and Transition SST concluding the last one show more realistic flow features. Pitch angles of 0º, -6º and -10º have been tested with Tip Speed Ratios ranging from 0.7 and 1.6. The no null pitch angles improve the performance of the wind turbine. Instantaneous and averaged power coefficients as well as detailed flow field around the airfoils are showed.

  12. Numerical study of dense adjoint matter in two color QCD

    International Nuclear Information System (INIS)

    Hands, S.; Morrison, S.; Scorzato, L.; Oevers, M.

    2000-06-01

    We identify the global symmetries of SU(2) lattice gauge theory with N flavors of staggered fermion in the presence of a quark chemical potential μ, for fermions in both fundamental and adjoint representations, and anticipate likely patterns of symmetry breaking at both low and high densities. Results from numerical simulations of the model with N=1 adjoint flavor on a 4 3 x 8 lattice are presented, using both hybrid Monte Carlo and two-step multi-boson algorithms. It is shown that the sign of the fermion determinant starts to fluctuate once the model enters a phase with non-zero baryon charge density. HMC simulations are not ergodic in this regime, but TSMB simulations retain ergodicity even in the dense phase, and in addition appear to show superior decorrelation. The HMC results for the equation of state and the pion mass show good quantitative agreement with the predictions of chiral perturbation theory, which should hold only for N≥2. The TSMB results incorporating the sign of the determinant support a delayed onset transition, consistent with the pattern of symmetry breaking expected for N=1. (orig.)

  13. Study on the numerical analysis of nuclear reactor kinetics equations

    International Nuclear Information System (INIS)

    Yang, J.C.

    1980-01-01

    A two-step alternating direction explict method is proposed for the solution of the space-and time-dependent diffusion theory reactor kinetics equations in two space dimensions as a special case of the general class of alternating direction implicit method and the truncation error of this method is estimated. To test the validity of this method it is applied to the Pressurized Water Reactor and CANDU-PHW reactor which have been operating and underconstructing in Korea. The time dependent neutron flux of the PWR reactor during control rod insertion and time dependent neutronic power of CANDU-PHW reactor in the case of postulated loss of coolant accident are obtained from the numerical calculation results. The results of the PWR reactor problem are shown the close agreement between implicit-difference method used in the TWIGL program and this method, and the results of the CANDU-PHW reactor are compared with the results of improved quasistic method and modal method. (Author)

  14. Global and Arctic climate engineering: numerical model studies.

    Science.gov (United States)

    Caldeira, Ken; Wood, Lowell

    2008-11-13

    We perform numerical simulations of the atmosphere, sea ice and upper ocean to examine possible effects of diminishing incoming solar radiation, insolation, on the climate system. We simulate both global and Arctic climate engineering in idealized scenarios in which insolation is diminished above the top of the atmosphere. We consider the Arctic scenarios because climate change is manifesting most strongly there. Our results indicate that, while such simple insolation modulation is unlikely to perfectly reverse the effects of greenhouse gas warming, over a broad range of measures considering both temperature and water, an engineered high CO2 climate can be made much more similar to the low CO2 climate than would be a high CO2 climate in the absence of such engineering. At high latitudes, there is less sunlight deflected per unit albedo change but climate system feedbacks operate more powerfully there. These two effects largely cancel each other, making the global mean temperature response per unit top-of-atmosphere albedo change relatively insensitive to latitude. Implementing insolation modulation appears to be feasible.

  15. A numerical study of two interacting coronal mass ejections

    Directory of Open Access Journals (Sweden)

    J. M. Schmidt

    2004-06-01

    Full Text Available The interaction in the solar wind between two coronal mass ejections (CMEs is investigated using numerical simulations. We show that the nature of the interaction depends on whether the CME magnetic structures interact, but in all cases the result is an equilisation of the speed of the two CMEs. In the absence of magnetic interaction, the forward shock of the faster trailing CME interacts with the slow leading CME, and accelerates it. When the two CMEs have magnetic fields with the same sense of rotation, magnetic reconnection occurs between the two CMEs, leading to the formation of a single magnetic structure: in the most extreme cases, one CME "eats" the other. When the senses of rotation are opposite, reconnection does not occur, but the CMEs collide in a highly non-elastic manner, again forming a single structure. The possibility of enhanced particle acceleration in such processes is assessed. The presence of strong magnetic reconnection provides excellent opportunities for the acceleration of thermal particles, which then form a seed population for further acceleration at the CME shocks. The presence of a large population of seed particles will thus lead to an overall increase in energetic particle fluxes, as suggested by some observations.

  16. [Hand eczema in children. Clinical and epidemiological study of the population referred to a tertiary hospital].

    Science.gov (United States)

    Ortiz-Salvador, José María; Subiabre-Ferrer, Daniela; García Rabasco, Ana; Esteve-Martínez, Altea; Zaragoza-Ninet, Violeta; Alegre de Miquel, Víctor

    2017-08-21

    Hand eczema is a frequent disease in adults. Diagnosing the cause of hand eczema is difficult due to different classifications. There is lack of evidence on hand eczema and its causes in children. A total of 389 children between 0 and 16 years were identified between 1996 and 2016, from whom 42 (10.8%) with exclusively hand eczema were selected. In all cases a standard battery of epicutaneous patch tests was performed, as well as additional batteries depending on the clinical suspicion. The clinical and epidemiological features of these children were recorded and compared against children with eczema in other locations. The 42 children with hand eczema included 25 (60.5%) girls, and 17 (40.5%) boys, with a mean age of 10.6 +- 3.9 years, and did not differ from that of children with eczema in other locations. The definitive diagnosis after patch-testing was Atopic Dermatitis in 15 cases, Allergic Contact Dermatitis in 14 patients, Endogenous Vesiculous Eczema in 6 cases, Endogenous Hyperkeratotic Eczema in 5 cases, and Irritant Contact Dermatitis in 2 cases. The most frequent allergens detected were thiomersal (9 cases), nickel (5 cases), mercury (5 cases), and cobalt (4 cases). Hand eczema is a common condition in children. The most common cause is atopic dermatitis, although cases of allergic contact dermatitis manifesting as hand eczema are not uncommon. Any child with eczema of hands in whom an allergic cause is suspected should be referred for patch- testing. Copyright © 2017. Publicado por Elsevier España, S.L.U.

  17. Robotic Hand

    Science.gov (United States)

    1993-01-01

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

  18. Quantification of Hand Motor Symptoms in Parkinson's Disease: A Proof-of-Principle Study Using Inertial and Force Sensors.

    Science.gov (United States)

    van den Noort, Josien C; Verhagen, Rens; van Dijk, Kees J; Veltink, Peter H; Vos, Michelle C P M; de Bie, Rob M A; Bour, Lo J; Heida, Ciska T

    2017-10-01

    This proof-of-principle study describes the methodology and explores and demonstrates the applicability of a system, existing of miniature inertial sensors on the hand and a separate force sensor, to objectively quantify hand motor symptoms in patients with Parkinson's disease (PD) in a clinical setting (off- and on-medication condition). Four PD patients were measured in off- and on- dopaminergic medication condition. Finger tapping, rapid hand opening/closing, hand pro/supination, tremor during rest, mental task and kinetic task, and wrist rigidity movements were measured with the system (called the PowerGlove). To demonstrate applicability, various outcome parameters of measured hand motor symptoms of the patients in off- vs. on-medication condition are presented. The methodology described and results presented show applicability of the PowerGlove in a clinical research setting, to objectively quantify hand bradykinesia, tremor and rigidity in PD patients, using a single system. The PowerGlove measured a difference in off- vs. on-medication condition in all tasks in the presented patients with most of its outcome parameters. Further study into the validity and reliability of the outcome parameters is required in a larger cohort of patients, to arrive at an optimal set of parameters that can assist in clinical evaluation and decision-making.

  19. An observational study of the hand hygiene initiative: a comparison of preintervention and postintervention outcomes

    Science.gov (United States)

    Mukerji, Amit; Narciso, Janet; Moore, Christine; McGeer, Allison; Kelly, Edmond; Shah, Vibhuti

    2013-01-01

    Objectives To evaluate the impact of implementing a simple, user-friendly eLearning module on hand hygiene (HH) compliance and infection rates. Design Preintervention and postintervention observational study. Participants All neonates admitted to the neonatal intensive care unit (NICU) over the study period were eligible for participation and were included in the analyses. A total of 3422 patients were admitted over a 36-month span (July 2009 to June 2012). Interventions In the preintervention and postintervention periods (phases I and II), all healthcare providers were trained on HH practices using an eLearning module. The principles of the ‘4 moments of HH’ and definition of ‘baby space’ were incorporated using interactive tools. The intervention then extended into a long-term sustainability programme (phase III), including the requirement of an annual recertification of the module and introduction of posters and screensavers throughout the NICU. Primary and secondary outcome measures The primary outcome was HH compliance rates among healthcare providers in the three phases. The secondary outcome was healthcare-associated infection rates in the NICU. Results HH compliance rates declined initially in phase II then improved in phase III with the addition of a long-term sustainability programme (76%, 67% and 76% in phases I, II and III, respectively (pchallenging to implement and sustain with the need for ongoing reinforcement and education. PMID:23793705

  20. Control of a Supernumerary Robotic Hand by Foot: An Experimental Study in Virtual Reality.

    Science.gov (United States)

    Abdi, Elahe; Burdet, Etienne; Bouri, Mohamed; Bleuler, Hannes

    2015-01-01

    In the operational theater, the surgical team could highly benefit from a robotic supplementary hand under the surgeon's full control. The surgeon may so become more autonomous; this may reduce communication errors with the assistants and take over difficult tasks such as holding tools without tremor. In this paper, we therefore examine the possibility to control a third robotic hand with one foot's movements. Three experiments in virtual reality were designed to assess the feasibility of this control strategy, the learning curve of the subjects in different tasks and the coordination of foot movements with the two natural hands. Results show that the limbs are moved simultaneously, in parallel rather than serially. Participants' performance improved within a few minutes of practice without any specific difficulty to complete the tasks. Subjective assessment by the subjects indicated that controlling a third hand by foot has been easy and required only negligible physical and mental efforts. The sense of ownership was reported to improve through the experiments. The mental burden was not directly related to the level of motion required by a task, but depended on the type of activity and practice. The most difficult task was moving two hands and foot in opposite directions. These results suggest that a combination of practice and appropriate tasks can enhance the learning process for controlling a robotic hand by foot.

  1. Control of a Supernumerary Robotic Hand by Foot: An Experimental Study in Virtual Reality.

    Directory of Open Access Journals (Sweden)

    Elahe Abdi

    Full Text Available In the operational theater, the surgical team could highly benefit from a robotic supplementary hand under the surgeon's full control. The surgeon may so become more autonomous; this may reduce communication errors with the assistants and take over difficult tasks such as holding tools without tremor. In this paper, we therefore examine the possibility to control a third robotic hand with one foot's movements. Three experiments in virtual reality were designed to assess the feasibility of this control strategy, the learning curve of the subjects in different tasks and the coordination of foot movements with the two natural hands. Results show that the limbs are moved simultaneously, in parallel rather than serially. Participants' performance improved within a few minutes of practice without any specific difficulty to complete the tasks. Subjective assessment by the subjects indicated that controlling a third hand by foot has been easy and required only negligible physical and mental efforts. The sense of ownership was reported to improve through the experiments. The mental burden was not directly related to the level of motion required by a task, but depended on the type of activity and practice. The most difficult task was moving two hands and foot in opposite directions. These results suggest that a combination of practice and appropriate tasks can enhance the learning process for controlling a robotic hand by foot.

  2. NOTE: A preliminary study for non-invasive quantification of manganese in human hand bones

    Science.gov (United States)

    Aslam; Pejović-Milić, A.; Chettle, D. R.; McNeill, F. E.; Pysklywec, M. W.; Oudyk, J.

    2008-10-01

    Manganese (Mn) is a nutrient essential for regulating neurological and skeletal functions in the human body, but it is also toxic when humans are excessively exposed to Mn. Blood (or serum/plasma) and other body fluids reflect only the most recent exposure and rapidly return to within normal ranges, even when there has been a temporary excursion in response to exposure. In this context, we have been developing a non-invasive measurement of Mn stored in bone, using in vivo neutron activation analysis. Following feasibility studies, a first pilot study, using neutron activation analysis to measure Mn in the bones of the hand of ten healthy male human subjects, was conducted with the approval of the concerned research ethics boards. The participants of this study had no known history of exposure to Mn. Two volunteers were excluded from this study due to technical problems with their measurements. The inverse variance weighted mean value of Mn/Ca for the participants of this study is 0.12 ± 0.68 µg Mn/g Ca which is comparable within uncertainties with the estimated range of 0.16 0.78 µg Mn/g Ca and mean value of 0.63 ± 0.30 µg Mn/g Ca derived from cadaver data. It is recommended to investigate the use of the diagnostic technique for in vivo measurements of workers exposed occupationally to excessive amounts of Mn who could develop many-fold increased levels of Mn in bones as demonstrated through various animal studies. The technique needs further development to improve the precision of in vivo measurements in the non-exposed population.

  3. A preliminary study for non-invasive quantification of manganese in human hand bones

    International Nuclear Information System (INIS)

    Aslam; Pejovic-Milic, A; Chettle, D R; McNeill, F E; Pysklywec, M W; Oudyk, J

    2008-01-01

    Manganese (Mn) is a nutrient essential for regulating neurological and skeletal functions in the human body, but it is also toxic when humans are excessively exposed to Mn. Blood (or serum/plasma) and other body fluids reflect only the most recent exposure and rapidly return to within normal ranges, even when there has been a temporary excursion in response to exposure. In this context, we have been developing a non-invasive measurement of Mn stored in bone, using in vivo neutron activation analysis. Following feasibility studies, a first pilot study, using neutron activation analysis to measure Mn in the bones of the hand of ten healthy male human subjects, was conducted with the approval of the concerned research ethics boards. The participants of this study had no known history of exposure to Mn. Two volunteers were excluded from this study due to technical problems with their measurements. The inverse variance weighted mean value of Mn/Ca for the participants of this study is 0.12 ± 0.68 μg Mn/g Ca which is comparable within uncertainties with the estimated range of 0.16-0.78 μg Mn/g Ca and mean value of 0.63 ± 0.30 μg Mn/g Ca derived from cadaver data. It is recommended to investigate the use of the diagnostic technique for in vivo measurements of workers exposed occupationally to excessive amounts of Mn who could develop many-fold increased levels of Mn in bones as demonstrated through various animal studies. The technique needs further development to improve the precision of in vivo measurements in the non-exposed population. (note)

  4. BIOCHEMISTRYGUIDE: A GUIDE TO STUDY BIOCHEMISTRY IN THE PALM OF YOUR HAND

    Directory of Open Access Journals (Sweden)

    M. L.C. Zago

    2015-08-01

    Full Text Available The new generation has grown driven by the digital technologies. Nowadays, the access to information has extended to the mobile technologies, like cell phones and tablets, increasing the technological resources for use in education. Educational institutions are opening more and more space to technologies, which have a new teaching, and learning methodology. The internet is an inexhaustible source of knowledge. With so much available material, the student finds difficulties in choosing the best source to study. Develop a cell phone app that works as a biochemistry study guide, providing materials from safe source and easy access. The app was developed at the website "Factory of apps", for free, and available for all the operational systems (Android, IOS, windows, enabling the download in any device. Were inserted in it materials like: summaries of the main subjects dealt in the discipline with clear and objective language, scientific articles to complementary reading, video-classes and exercises. Offering fast and practical access to the material, facilitating the process of studying and learning. The student does not have to let his mobile phone in preference of studying and does not find difficulties to filter available information in the internet. After the app's use, was applied a questionnaire to the participating students for this tool's assessment, such as layout, quality of the available material, access facilities. All the participants have approved the listed aspects and have said that the use of the tool can help at the biochemistry study, by the reliable material and by being available in a mobile device providing quick and immediate access, at any time in the palm of the hand. The use of this tool can be applied in the classroom to help the professor in getting materials and to help the students by its practicality.Acknowledgements: CnpQ, Unipampa. Keywords: App, BiochemistryGuide, Biochemistry

  5. A numerical study of ionospheric profiles for mid-latitudes

    Directory of Open Access Journals (Sweden)

    S.-R. Zhang

    1995-05-01

    Full Text Available This paper presents a numerical model and results for the mid-latitude ionospheric profile below the peak of the F2-layer. The basis of the model is the solving of equations for four ionic species O+, NO+, O+2 and N+2, as well as the meta-stable O+(2D and O+(2P. Diffusion and wind-induced drifts and 21 photo-chemical reactions are also taken into account. Neutral atmospheric density and temperature are derived from the MSIS86 model and solar extreme ultraviolate irradiance from the EUV91 model. In an effort to obtain a more realistic ionospheric profile, the key point at foF2 and hmF2 is fitted from the simulation to observations. The model also utilizes the vertical drifts derived from ionosonde data with the help of the Servo model. It is shown that the ionospheric height of peak can be reproduced more accurately under the derived vertical drifts from the Servo theory than with the HWM90 model. Results from the simulation are given for Wuchang (30.5°N, 114.4°E and Wakkanai (45.6°N, 141.7°E, showing the profile changes with season and solar activity, and the E-F valley structure (the depth and the width. This simulation also reveals the importance of meta-stable ions and dynamical transport processes on the formation of the F1-ledge and F1-F2 valley.

  6. Numerical study of jet noise radiated by turbulent coherent structures

    Energy Technology Data Exchange (ETDEWEB)

    Bastin, F.

    1995-08-01

    a numerical approach of jet mixing noise prediction is presented, based on the assumption that the radiated sound field is essentially due to large-scale coherent turbulent structures. A semi-deterministic turbulence modelling is used to obtain the flow coherent fluctuations. This model is derived from the k-{epsilon} model and validated on the 2-D compressible shear layer case. Three plane jets at Mach 0.5, 1.33 and 2 are calculated. The semi-deterministic modelling yields a realistic unsteady representation of plane jets but not appropriate for axisymmetric jet computations. Lighthill`s analogy is used to estimate the noise radiated by the flow. Three integral formulations of the theory are compared and the most suitable one is expressed in space-time Fourier space. This formulation is associated to a geometrical interpretation of acoustic computations in (k, {omega}) plane. The only contribution of coherent structures cannot account for the high-frequency radiation of a subsonic jet and thus, the initial assumption is not verified in the subsonic range. The interpretation of Lighthill`s analogy in (k, {omega}) plane allows to conclude that the missing high-frequency components are due to the inner structure of the coherent motion. For supersonic jets, full acoustic spectra are obtained, at least in the forward arc where the dominant radiation is emitted. For the fastest jet (M = 2), no Mach waves are observed, which may be explained by a ratio of the structures convection velocity to the jet exit velocity lower in plane than in circular jets. This point is confirmed by instability theory calculations. Large eddy simulations (LES) were performed for subsonic jets. Data obtained in the plane jet case show that this technique allows only a slight improvement of acoustic results. To obtain a satisfactory high-frequency radiation, very fine grids should be considered, and the 2-D approximation could not be justified anymore. (Abstract Truncated)

  7. Numerical study on oil supply system of a rotary compressor

    International Nuclear Information System (INIS)

    Wu, Jianhua; Wang, Gang

    2013-01-01

    The oil supply system is a crucial reliability issue for rotary compressors. This paper provides a general method for analyzing the oil supply system of a rotary compressor by using computational fluid dynamics (CFD). The process includes establishing the physical model, dividing computational grid, setting boundary conditions, calculating leakage rates through the roller end clearances, translating the dynamic issue into the static issue and so on. Validation of the rationality of the oil supply system model has been made by the measurement of the main bearing oil flow rates. The effects of operating conditions of the compressor, the oil level height of the oil sump and the main design parameters of the oil supply system on the oil supply characteristics are analyzed by numerical simulation. It is found that the main bearing oil flow rate varies circularly along with the rotation of the shaft. The shape and inclination angle of the spiral groove also influence the main bearing oil flow rate. The oil leakage rates through the roller end clearances depend largely on the operating conditions. In addition, the oil level height of the oil sump has a huge effect on the total oil flow rate. -- Highlights: • A CFD method for analyzing the oil supply system of rotary compressor is presented. • Leakage through the roller end clearances depends on the operating condition. • Groove shape and inclination angle are the main design parameters of spiral grooves. • A parabolic interface of oil and gas can be formed in the gallery of the shaft. • Single-flow model and steady solver can be applied to the oil supply system

  8. The WISTAH hand study: A prospective cohort study of distal upper extremity musculoskeletal disorders

    Directory of Open Access Journals (Sweden)

    Garg Arun

    2012-06-01

    Full Text Available Abstract Background Few prospective cohort studies of distal upper extremity musculoskeletal disorders have been performed. Past studies have provided somewhat conflicting evidence for occupational risk factors and have largely reported data without adjustments for many personal and psychosocial factors. Methods/design A multi-center prospective cohort study was incepted to quantify risk factors for distal upper extremity musculoskeletal disorders and potentially develop improved methods for analyzing jobs. Disorders to analyze included carpal tunnel syndrome, lateral epicondylalgia, medial epicondylalgia, trigger digit, deQuervain’s stenosing tenosynovitis and other tendinoses. Workers have thus far been enrolled from 17 different employment settings in 3 diverse US states and performed widely varying work. At baseline, workers undergo laptop administered questionnaires, structured interviews, two standardized physical examinations and nerve conduction studies to ascertain demographic, medical history, psychosocial factors and current musculoskeletal disorders. All workers’ jobs are individually measured for physical factors and are videotaped. Workers are followed monthly for the development of musculoskeletal disorders. Repeat nerve conduction studies are performed for those with symptoms of tingling and numbness in the prior six months. Changes in jobs necessitate re-measure and re-videotaping of job physical factors. Case definitions have been established. Point prevalence of carpal tunnel syndrome is a combination of paraesthesias in at least two median nerve-served digits plus an abnormal nerve conduction study at baseline. The lifetime cumulative incidence of carpal tunnel syndrome will also include those with a past history of carpal tunnel syndrome. Incident cases will exclude those with either a past history or prevalent cases at baseline. Statistical methods planned include survival analyses and logistic regression. Discussion A

  9. An observational study of implicit motor imagery using laterality recognition of the hand after stroke.

    Science.gov (United States)

    Amesz, Sarah; Tessari, Alessia; Ottoboni, Giovanni; Marsden, Jon

    2016-01-01

    To explore the relationship between laterality recognition after stroke and impairments in attention, 3D object rotation and functional ability. Observational cross-sectional study. Acute care teaching hospital. Thirty-two acute and sub-acute people with stroke and 36 healthy, age-matched controls. Laterality recognition, attention and mental rotation of objects. Within the stroke group, the relationship between laterality recognition and functional ability, neglect, hemianopia and dyspraxia were further explored. People with stroke were significantly less accurate (69% vs 80%) and showed delayed reaction times (3.0 vs 1.9 seconds) when determining the laterality of a pictured hand. Deficits either in accuracy or reaction times were seen in 53% of people with stroke. The accuracy of laterality recognition was associated with reduced functional ability (R(2) = 0.21), less accurate mental rotation of objects (R(2) = 0.20) and dyspraxia (p = 0.03). Implicit motor imagery is affected in a significant number of patients after stroke with these deficits related to lesions to the motor networks as well as other deficits seen after stroke. This research provides new insights into how laterality recognition is related to a number of other deficits after stroke, including the mental rotation of 3D objects, attention and dyspraxia. Further research is required to determine if treatment programmes can improve deficits in laterality recognition and impact functional outcomes after stroke.

  10. Case Study: Physical Capacity and Nutritional Status Before and After a Single-Handed Yacht Race.

    Science.gov (United States)

    Ghiani, Giovanna; Magnani, Sara; Doneddu, Azzurra; Sainas, Gianmarco; Pinna, Virginia; Caboi, Marco; Palazzolo, Girolamo; Tocco, Filippo; Crisafulli, Antonio

    2017-12-18

    During solitary sailing the sailor is exposed to sleep deprivation and difficulties in consuming regular meals. Sailor weight loss is often reported. In the present case study we describe changes in the physical capacity and the nutritional status of an athlete attempting a single-handed yacht race around the globe. An Italian male ocean racer (GM) asked for our help to reach an optimum level of physical and nutritional preparation. We planned his diet after assessing his anthropometric parameters and body composition as well as his usual energy intake and nutritional expenditure. The diet consisted in 120 meals stored in sealed plastic bags. Before his departure, GM performed two incremental exercise tests (cycle- and arm crank- ergometry) to assess his physical capacity. Cardiac functions were also estimated by Doppler echocardiography. All measures and exercise tests were repeated 10 days after GM finished the race, which lasted 64 days. Anthropometric measures did not change significantly, with the exception of Arm Fat Area and Thigh Muscle area, which decreased. There were evident increments in maximum oxygen intake and maximum workload during arm cranking after the race. On the contrary, maximum oxygen uptake and maximum workload decreased during cycling. Finally, End Diastolic and Stroke Volume decreased after the race. It was concluded that nutritional counseling was useful to avoid excessive changes in the nutritional status and body composition due to 64 days of solitary navigation. However, a reduction in physical leg capacity and cardiovascular functions secondary to legs disuse were present.

  11. Thumb Reach of Indonesian Young Adult When Interacting with Touchscreen of Single-Handed Device: A Preliminary Study

    Science.gov (United States)

    Umami, M. K.

    2018-01-01

    This study is a preliminary survey on thumb reach of Indonesian population when interacting with single-handed device. This study was aimed to know the thumb reach envelope on the screen of mobile phone. The correlation between the thumb reach vs. the hand length and thumb length was also identified. Thirty young adults participated in the study. All participants had normal body stature and were right-handed person. In the observational phase, the participant was asked to colour the canvas area on the screen of the mobile phone by using his/her thumb. The participant had to complete the task by applying the single hand interaction. The participant should grab the mobile phone as he/she use it normally in his/her daily activities. The thumb reach envelope of participants was identified from the coloured area of the canvas. The results of this study found that participants with a large hand length and thumb length tend to have a large thumb reach. The results of this study also show the thumb reach area of the participants is forming an elliptical shape that runs from the northeast to southwest on the device screen.

  12. Diffusion tensor magnetic resonance imaging for hand and foot fibers location at the corona radiata: comparison with two lesion studies

    Directory of Open Access Journals (Sweden)

    Dong-Hoon eLee

    2014-09-01

    Full Text Available The corticospinal tract is the motor pathway in the human brain, and corona radiata is an important location to diagnose stroke. We detected hand and foot motor fiber tracts in the corona radiata to investigate accurate locations using diffusion tensor imaging and functional imaging. Ten right-handed normal volunteers participated in this study. We used a probabilistic tracking algorithm, a brain normalization method, and functional imaging results to set out ROIs. Moreover, our results were compared to previous results of lesion studies to confirm their accuracy and usefulness. The location measurements were performed in two index types; anteriority index on the basis of the anterior and posterior location of lateral ventricle, laterality index on the basis of the left and right location. The anteriority indices were 56.40/43.2 (hand/foot at the upper CR and lower CR 40.72/30.90 at the lower CR. The measurements of anteriority and laterality of motor fibers were represented as anteriority index 0.40/0.31 and laterality index 0.60/0.47 (hand/foot. Our results showed that the hand and foot fibers were in good agreements with previous lesion studies. This study and approaches can be used as a standard for diffusion tensor image combined with lesion location studies in patients who need rehabilitation or follow up.

  13. A Study on Using Hands-On Science Inquiries to Promote the Geology Learning of Preservice Teachers

    Science.gov (United States)

    Lai, Ching-San

    2015-01-01

    This study aims to investigate the geology learning performance of preservice teachers. A total of 31 sophomores (including 11 preservice teachers) from an educational university in Taiwan participated in this study. The course arrangements include class teaching and hands-on science inquiry activities. The study searches both quantitative and…

  14. Improving airplane boarding time : A review, a field study and an experiment with a new way of hand luggage stowing

    NARCIS (Netherlands)

    Coppens, J.; Dangal, Sagar; Vendel, M.E.; Anjani, S.; Akkerman, Stefan; Hiemstra-van Mastrigt, S.; Vink, P.

    2018-01-01

    The airplane (de)boarding process is not organized optimally. The goal of this paper is to search for improvement possibilities. In this paper literature is reviewed, boarding characteristics are studied in a field study and a pilot study with a new way of hand luggage stowing is performed. Computer

  15. Numerical Simulations of Kinetic Alfvén Waves to Study Spectral ...

    Indian Academy of Sciences (India)

    Numerical Simulations of Kinetic Alfvén Waves to Study Spectral. Index in Solar Wind Turbulence and Particle Heating. R. P. Sharma. ∗. & H. D. Singh. Center for Energy Studies, Indian Institute of Technology, Delhi 110 016, India. ∗ e-mail: rpsharma@ces.iitd.ernet.in. Abstract. We present numerical simulations of the ...

  16. Proceeding of 1998-workshop on MHD computations. Study on numerical methods related to plasma confinement

    International Nuclear Information System (INIS)

    Kako, T.; Watanabe, T.

    1999-04-01

    This is the proceeding of 'Study on Numerical Methods Related to Plasma Confinement' held in National Institute for Fusion Science. In this workshop, theoretical and numerical analyses of possible plasma equilibria with their stability properties are presented. These are also various talks on mathematical as well as numerical analyses related to the computational methods for fluid dynamics and plasma physics. The 14 papers are indexed individually. (J.P.N.)

  17. Proceeding of 1998-workshop on MHD computations. Study on numerical methods related to plasma confinement

    Energy Technology Data Exchange (ETDEWEB)

    Kako, T.; Watanabe, T. [eds.

    1999-04-01

    This is the proceeding of 'Study on Numerical Methods Related to Plasma Confinement' held in National Institute for Fusion Science. In this workshop, theoretical and numerical analyses of possible plasma equilibria with their stability properties are presented. These are also various talks on mathematical as well as numerical analyses related to the computational methods for fluid dynamics and plasma physics. The 14 papers are indexed individually. (J.P.N.)

  18. Numerical Study of Transition of an Annular Lift Fan Aircraft

    OpenAIRE

    Yun Jiang; Bo Zhang

    2016-01-01

    The present study aimed at studying the transition of annular lift fan aircraft through computational fluid dynamics (CFD) simulations. The oscillations of lift and drag, the optimization for the figure of merit, and the characteristics of drag, yawing, rolling and pitching moments in transition are studied. The results show that a two-stage upper and lower fan lift system can generate oscillations of lift and drag in transition, while a single-stage inner and outer fan lift system can elimin...

  19. Acute hand and wrist injuries sustained during recreational mountain biking: a prospective study.

    Science.gov (United States)

    Bush, Kevin; Meredith, Steve; Demsey, Daniel

    2013-12-01

    Recreational mountain biking continues to increase in popularity and is a significant source of traumatic injury, including injuries to the hand and wrist. A prospective survey of all hand and wrist injuries sustained while participating in recreational mountain biking presenting to the emergency department at the Municipality of Whistler and the District of Squamish was conducted over a 12-month consecutive period. An analysis of 765 unique emergency department visits with 1,079 distinct injuries was performed. Of these injuries, 511 were sustained to the upper limb. Injury to the metacarpal and metacarpal phalangeal joints was the most common hand injury (52) followed by proximal phalanx and proximal interphalangeal joint (20). Mountain biking is a frequent source of a variety of upper limb trauma, and preventative efforts are necessary to minimize the burden of these injuries.

  20. Numerical modelling of fluid-rock interactions: Lessons learnt from carbonate rocks diagenesis studies

    Science.gov (United States)

    Nader, Fadi; Bachaud, Pierre; Michel, Anthony

    2015-04-01

    contribution is based on several studies that were undertaken on carbonate rocks diagenesis in some of the major reservoir rocks in the Middle East and outcrop analogues in Europe. Here, the main processes at hand are related to fracture-related dolomitization and carbonate dissolution. We would like to present the workflows we have followed and the questioning that resulted for a series of case studies. The way forward, seems evident as the integration of workflows and numerical modelling tools at different scales, bringing better constrains on the boundary data and less uncertainty.

  1. Epidemiology of hand foot mouth disease in Northern Thailand in 2016: A prospective cohort study

    Directory of Open Access Journals (Sweden)

    Panupong Upala

    2017-06-01

    Full Text Available Objective: To determine the correlations between the meteorological data and the number of hand foot mouth disease (HFMD cases in 2016 in Northern Thailand, and to estimate the medical costs. Methods: A prospective cohort study was conducted. Data on numbers of HFMD cases were collected from 49 hospitals in three different provinces in Northern Thailand: 16 hospitals from Chiang Rai Province, 7 hospitals from Pha Yao Province, and 26 hospitals from Chiang Mai Province. A questionnaire had been developed and tested for validity and reliability before used. The specific form for collecting meteorological data was developed and used in the field. All information was recorded in the same data spread sheet before analysis. Chi-square and correlation tests were used for explaining the epidemiology of HFMD in the areas. An alpha error at 0.05 was used to determine the statistical significance level. Results: A total of 8 261 cases were analyzed in the study. 56.0% were males, 97.5% aged less than 6 years, 82.6% were out-patient department (OPD cases, 75.5% were reported in raining season, and 43.2% were from Chiang Mai Province. The number of HFMD cases had statistically significant correlations with temperature, air pressure, relative humidity, and rainfall amount. Averagely, 216 baht and 3 678 baht per case per visit had to be expended for medical cost in OPD and IPD cases, respectively. Most of the cases had been reported in the border areas: Thai-Myanmar, and Thai-Lao. Conclusions: Thailand health care system should provide a concrete schedule for taking care of HFMD patients during raining season, and should develop an effective preventive and control program for HFMD particularly among children less than 6 years.

  2. Second-hand smoking and carboxyhemoglobin levels in children: a prospective observational study.

    Science.gov (United States)

    Yee, Branden E; Ahmed, Mohammed I; Brugge, Doug; Farrell, Maureen; Lozada, Gustavo; Idupaganthi, Raghu; Schumann, Roman

    2010-01-01

    To establish baseline noninvasive carboxyhemoglobin (COHb) levels in children and determine the influence of exposure to environmental sources of carbon monoxide (CO), especially environmental tobacco smoke, on such levels. Second-hand smoking may be a risk factor for adverse outcomes following anesthesia and surgery in children (1) and may potentially be preventable. Parents and their children between the ages of 1-12 were enrolled on the day of elective surgery. The preoperative COHb levels of the children were assessed noninvasively using a CO-Oximeter (Radical-7 Rainbow SET Pulse CO-Oximeter; Masimo, Irvine, CA, USA). The parents were asked to complete an environmental air-quality questionnaire. The COHb levels were tabulated and correlated with responses to the survey in aggregate analysis. Statistical analyses were performed using the nonparametric Mann-Whitney and Kruskal-Wallis tests. P < 0.05 was statistically significant. Two hundred children with their parents were enrolled. Children exposed to parental smoking had higher COHb levels than the children of nonsmoking controls. Higher COHb values were seen in the youngest children, ages 1-2, exposed to parental cigarette smoke. However, these trends did not reach statistical significance, and confidence intervals were wide. This study revealed interesting trends of COHb levels in children presenting for anesthesia and surgery. However, the COHb levels measured in our patients were close to the error margin of the device used in our study. An expected improvement in measurement technology may allow screening children for potential pulmonary perioperative risk factors in the future.

  3. Self-reported hand eczema among dental workers in Japan - a cross-sectional study.

    Science.gov (United States)

    Minamoto, Keiko; Watanabe, Takeshi; Diepgen, Thomas L

    2016-10-01

    Dental workers are considered to have a high risk of developing occupational hand eczema. To estimate the prevalence of work-related hand eczema and associated risk factors in dental workers in Japan. A self-administered questionnaire was sent by mail to all dental clinics of Kumamoto City, Japan. In addition, patch testing with 24 dentistry-related allergens was offered. In total, 46.4% of dental workers (n = 528: response 31.4%, based on 97 clinics) reported a lifetime history of chronic hand eczema. The 1-year prevalence was 36.2%. According to logistic regression analysis, the most important risk factors for the 1-year prevalence were a personal history of atopic dermatitis [odds ratio (OR) 4.7, 95% confidence interval (CI): 2.2-8.8], asthma and/or allergic rhinitis (OR 2.0, 95%CI: 1.3-3.0), dry skin (OR 1.7, 95%CI: 1.1-2.7), shorter duration of work (OR 2.0, 95%CI: 1.2-3.5 for up to 10 years versus >20 years), and washing hands >10 times per day (OR 1.6, 95%CI: 1.0-2.5). Fifty-four workers were patch tested. Rubber chemicals and acrylates were the most frequent occupationally relevant contact allergens. Dental workers in Japan have a high prevalence of hand eczema. Health education to prevent hand eczema and more frequent patch testing are needed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Home-based hand rehabilitation with a robotic glove in hemiplegic patients after stroke: a pilot feasibility study.

    Science.gov (United States)

    Bernocchi, Palmira; Mulè, Chiara; Vanoglio, Fabio; Taveggia, Giovanni; Luisa, Alberto; Scalvini, Simonetta

    2018-03-01

    To evaluate the feasibility and safety of home rehabilitation of the hand using a robotic glove, and, in addition, its effectiveness, in hemiplegic patients after stroke. In this non-randomized pilot study, 21 hemiplegic stroke patients (Ashworth spasticity index ≤ 3) were prescribed, after in-hospital rehabilitation, a 2-month home-program of intensive hand training using the Gloreha Lite glove that provides computer-controlled passive mobilization of the fingers. Feasibility was measured by: number of patients who completed the home-program, minutes of exercise and number of sessions/patient performed. Safety was assessed by: hand pain with a visual analog scale (VAS), Ashworth spasticity index for finger flexors, opponents of the thumb and wrist flexors, and hand edema (circumference of forearm, wrist and fingers), measured at start (T0) and end (T1) of rehabilitation. Hand motor function (Motricity Index, MI), fine manual dexterity (Nine Hole Peg Test, NHPT) and strength (Grip test) were also measured at T0 and T1. Patients performed, over a mean period 56 (49-63) days, a total of 1699 (1353-2045) min/patient of exercise with Gloreha Lite, 5.1 (4.3-5.8) days/week. Seventeen patients (81%) completed the full program. The mean VAS score of hand pain, Ashworth spasticity index and hand edema did not change significantly at T1 compared to T0. The MI, NHPT and Grip test improved significantly (p = 0.0020, 0.0156 and 0.0024, respectively) compared to baseline. Gloreha Lite is feasible and safe for use in home rehabilitation. The efficacy data show a therapeutic effect which need to be confirmed by a randomized controlled study.

  5. Numerical study of aerodynamic effects on road vehicles lifting surfaces

    Science.gov (United States)

    Cernat, Mihail Victor; Cernat Bobonea, Andreea

    2017-01-01

    The aerodynamic performance analysis of road vehicles depends on the study of engine intake and cooling flow, internal ventilation, tire cooling, and overall external flow as the motion of air around a moving vehicle affects all of its components in one form or another. Due to the complex geometry of these, the aerodynamic interaction between the various body components is significant, resulting in vortex flow and lifting surface shapes. The present study, however focuses on the effects of external aerodynamics only, and in particular on the flow over the lifting surfaces of a common compact car, designed especially for this study.

  6. Experimental and Numerical Studies of Atmosphere Water Interactions

    KAUST Repository

    Bou-Zeid, Elie

    2011-07-04

    Understanding and quantifying the interaction of the atmosphere with underlying water surfaces is of great importance for a wide range of scientific fields such as water resources management, climate studies of ocean-atmosphere exchange, and regional weat

  7. Numerical studies of transport processes in Tokamak plasma

    International Nuclear Information System (INIS)

    Spineanu, F.; Vlad, M.

    1984-09-01

    The paper contains the summary of a set of studies of the transport processes in tokamak plasma, performed with a one-dimensional computer code. The various transport models (which are implemented by the expressions of the transport coefficients) are presented in connection with the regimes of the dynamical development of the discharge. Results of studies concerning the skin effect and the large scale MHD instabilities are also included

  8. Experimental and numerical studies on two-stage combustion of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Houshfar, Eshan

    2012-07-01

    In this thesis, two-stage combustion of biomass was experimentally/numerically investigated in a multifuel reactor. The following emissions issues have been the main focus of the work: 1- NOx and N2O 2- Unburnt species (CO and CxHy) 3- Corrosion related emissions.The study had a focus on two-stage combustion in order to reduce pollutant emissions (primarily NOx emissions). It is well known that pollutant emissions are very dependent on the process conditions such as temperature, reactant concentrations and residence times. On the other hand, emissions are also dependent on the fuel properties (moisture content, volatiles, alkali content, etc.). A detailed study of the important parameters with suitable biomass fuels in order to optimize the various process conditions was performed. Different experimental studies were carried out on biomass fuels in order to study the effect of fuel properties and combustion parameters on pollutant emissions. Process conditions typical for biomass combustion processes were studied. Advanced experimental equipment was used in these studies. The experiments showed the effects of staged air combustion, compared to non-staged combustion, on the emission levels clearly. A NOx reduction of up to 85% was reached with staged air combustion using demolition wood as fuel. An optimum primary excess air ratio of 0.8-0.95 was found as a minimizing parameter for the NOx emissions for staged air combustion. Air staging had, however, a negative effect on N2O emissions. Even though the trends showed a very small reduction in the NOx level as temperature increased for non-staged combustion, the effect of temperature was not significant for NOx and CxHy, neither in staged air combustion or non-staged combustion, while it had a great influence on the N2O and CO emissions, with decreasing levels with increasing temperature. Furthermore, flue gas recirculation (FGR) was used in combination with staged combustion to obtain an enhanced NOx reduction. The

  9. Children's exposure to second hand smoke at home: A cross-sectional study in Portugal

    Directory of Open Access Journals (Sweden)

    Paulo D. Vitória

    2015-07-01

    Full Text Available Second-hand tobacco smoke (SHS is a major indoor pollutant that causes serious health problems for all exposed, especially children. Children are often exposed to SHS at home, due to parental or other households’ or guests’ smoking. This study describes Portuguese children's exposure to SHS at home (total and by Portuguese main regions.In 2010/2011, a questionnaire was applied to a sample of Portuguese children in the 4th grade (N = 3187, mean age 9.05 ± 0.7 years, 51.1% male. Descriptive analysis, chi-square tests and crude odds ratios were performed.Of the participants, 62.9% of those with smoking parents and 19.2% of those with non-smoking parents were exposed to SHS at their home. Parental smoking varied significantly among regions and was significantly associated with children's exposure to SHS at home.Children's exposure to SHS at home was high, especially if their parents smoke. Children living in Lisbon Region presented the highest SHS exposure rate. The association of SHS exposure with geographic regions suggests the influence of social and contextual factors on smoking behaviour and on tobacco control effectiveness. Our findings highlight the need to effectively prevent children's SHS exposure at their home and to develop tailored tobacco control measures by region. Keywords: Tobacco smoke pollution, Child welfare, Smoking, Tobacco, Parent–child relations

  10. Curcuma longa (Turmeric) for Prevention of Capecitabine-Induced Hand-Foot Syndrome: A Pilot Study.

    Science.gov (United States)

    Scontre, Vanessa Armenio; Martins, Janine Capobiango; de Melo Sette, Claudia Vaz; Mutti, Haila; Cubero, Daniel; Fonseca, Fernando; Del Giglio, Auro

    2017-11-02

    Hand-foot syndrome (HFS) is common and frequently occurs in the first cycle of treatment in approximately 40% to 50% of patients who receive capecitabine. Turmeric (Curcuma longa) is a plant used in Ayurvedic medicine with clinical activity in various inflammatory conditions. Our objective was to evaluate whether turmeric was active for the prevention of capecitabine-induced HFS. We included patients older than 18 years of age without previous exposure to capecitabine who were scheduled to receive this medication. Before starting treatment, after three weeks and at the end of six weeks, we evaluated dermatologic toxicity, conducted quality-of-life questionnaires (EORTC-QLQC30 and DLQI) and collected serum inflammatory biomarkers (inerleukin-6 (IL-6), tumor necrosis factor-a (TNF-a), C-reactive protein (CRP), and albumin). We administered turmeric at a dose of 4 g/day (2 pills 12 hours apart) starting at the beginning of capecitabine treatment and lasting six weeks. We included 40 patients whose mean age was 62 years. Most were female (80%), 52% had breast cancer, and 47.5% had GI tumors. After the first cycle of capecitabine treatment, we observed that 11 of 40 patients developed HFS (27.5%; 95% CI [15, 42]), whereas four patients developed HFS equal or superior to grade 2 (10%; 95% CI [3.3, 23]). We did not find any correlations between the inflammatory markers tested and HFS. We show that turmeric combined with capecitabine seems to produce a lower rate of HFS, especially grade 2 or higher. These findings need to be reproduced in larger controlled studies.

  11. STUDY AND NUMERICAL SIMULATION OF SOLAR SYSTEM FOR AIR HEATING

    Directory of Open Access Journals (Sweden)

    M. Ghodbane

    2016-01-01

    Full Text Available The use of solar energy in sunny countries, is an effective outil for compensate the lack in the energy, their benefits are not related only to its economic benefits but especially for the environmental protection, so we must find solutions to the problems of pollution. This work is a theoretical study of a solar flat plate collector ; air is used as the heat transfer fluid. In this study, we established in first step the calculation of solar radiation in various sites in Algeria (Adrar, El Oued, Bechar, Biskra and Tamanrasset. The second step is the parameters influence study of the sites and climate on the performance of our collector. The results obtained are encouraging for the use of this type in the heating in the winter, also it can be used in different kinds of drying.

  12. Localization in random bipartite graphs: Numerical and empirical study

    Science.gov (United States)

    Slanina, František

    2017-05-01

    We investigate adjacency matrices of bipartite graphs with a power-law degree distribution. Motivation for this study is twofold: first, vibrational states in granular matter and jammed sphere packings; second, graphs encoding social interaction, especially electronic commerce. We establish the position of the mobility edge and show that it strongly depends on the power in the degree distribution and on the ratio of the sizes of the two parts of the bipartite graph. At the jamming threshold, where the two parts have the same size, localization vanishes. We found that the multifractal spectrum is nontrivial in the delocalized phase, but still near the mobility edge. We also study an empirical bipartite graph, namely, the Amazon reviewer-item network. We found that in this specific graph the mobility edge disappears, and we draw a conclusion from this fact regarding earlier empirical studies of the Amazon network.

  13. The Safety of Transnational Imported Second-Hand Cars: A Case Study on Vehicle-to-Vehicle Crashes in Romania

    Directory of Open Access Journals (Sweden)

    Anatolie Coșciug

    2017-12-01

    Full Text Available Certain features of imported second-hand cars (e.g., age, degree of wear and tear, technical design can increase their likelihood for traffic crashes. Three official datasets which cover an eight year period (2008–2015 are used to test the connection between importation of second-hand cars and different types of traffic crashes. The traffic crashes database was provided by the Traffic Department of the General Inspectorate of Romanian Police (GIRPTD. The car registration database was provided by Driving-License and Vehicles-Registration Direction (DLVRD. Right-hand driving (RHD cars database was provided by the Romanian Automotive Registry (RAR. A spatio-temporal visualization of data was performed using Geographic Information System (GIS while for the statistical analysis we use regression models and Pearson-Correlation-coefficient. The analysis suggests that a significant part of the variation in the volume of traffic accidents can be explained by the volume of imported second-hand cars at the county level. Moreover, an even stronger direct relation exists between the number of imported second-hand cars and Severe Traffic Accidents but also in the case of RHD imported second-hand cars. The overall impact of imported second-hand cars on the traffic safety in Romania is significant but small in comparison to other types of car registration. Study results belong to the category of empirical evidence production which can improve the quality of existing traffic regulations focused both on organizing and ensuring traffic safety, and on the policy of sustainable transport infrastructure development.

  14. Lunar evolution: a combined numerical modelling and HPT experimental study

    NARCIS (Netherlands)

    de Vries, J.|info:eu-repo/dai/nl/313968519

    2012-01-01

    Recent studies, some of them using data from the Apollo seismic network from the 1960's and 1970's, others using newer data, have shown that part of the lunar core may still be fluid today. Furthermore, a possible partial melt zone has been detected in the deep mantle, just above the core-mantle

  15. Numerical study of Wavy Blade Section for Wind Turbines

    DEFF Research Database (Denmark)

    Kobæk, C. M.; Hansen, Martin Otto Laver

    2016-01-01

    than a flipper having a smooth trailing edge and thus could be potentially beneficial when catching food. A thorough literature study of the Wavy Blade concept is made and followed by CFD computations of two wavy blade geometries and a comparison with their baseline S809 airfoil at conditions more...

  16. Numerical Study of Radiation Emissions from the Plasma Focus

    International Nuclear Information System (INIS)

    Akel, M.; Salo, S.

    2013-12-01

    Ion populations of studied plasma have been calculated versus electron temperatures. The expected emission spectra (full, Bremsstrahlung, recombination, and line) of plasma focus operated with different gases (nitrogen, oxygen, neon, argon, krypton and xenon) have been studied for different conditions using POPULATE, SPECTRA, XRAYFIL and FLYCHK codes for non-local thermodynamic equilibrium model (NLTE). The suitable electron temperatures ranges for soft X-ray and extreme ultraviolet (EUV) emissions from plasma focus have been investigated. The Ratio- BPX65.F code has been written in FORTRAN 77 for studying the soft X-ray emission of plasma focus using BPX65 PIN Diode X-ray Spectrometer technique. The X-ray ratio curves for various electron temperatures with probable electron and ion densities of the studied plasma produced have been computed with the assumption of non-LTE model for the distribution of the ionic species. The calculated X-ray ratio curves have been compared with experimental results for the argon plasma focus. These ratio curves could be used for electron temperatures deduction of plasma focus (author).

  17. Phase conjugation of gap solitons: A numerical study

    Indian Academy of Sciences (India)

    We study the effect of a nearby phase-conjugate mirror (PCM) on the gap soliton of a. Kerr non-linear ... They are characterized by a sech field distribution corresponding to the ... It is a generalization of the earlier model proposed by Jose et.

  18. Qualitative and numerical study of Bianchi IX Models

    International Nuclear Information System (INIS)

    Francisco, G.; Matsas, G.E.A.

    1987-01-01

    The qualitative behaviour of trajectories in the Mixmaster universe is studied. The Lyapunov exponents computed directly from the differential equations and from the Poincare map are shown to be different. A detailed discussion of the role of these exponents in analysing the effect of chaos on trajectories is presented. (Author) [pt

  19. Numerical Study of Noise Characteristics in Overexpanded Jet Flows

    Science.gov (United States)

    2015-08-05

    Bourne, M., and Fisher, M. J., “The Noise from Shock Waves in Supersonic Jets,” AGARD - CP - 131, 1973, pp. 1-13. [2]. Tanna, H. K., “An Experimental Study...Journal, Volume 20, No. 1, 1982, pp. 68- 73 . [7]. Tam, C. K. W., and Tanna, H. K., “Shock Associated Noise of Supersonic Jets from Convergent

  20. Experimental and Numerical Study of Ceramic Foam Filtration

    Science.gov (United States)

    Laé, E.; Duval, H.; Rivière, C.; Le Brun, P.; Guillot, J.-B.

    Ceramic foam filtration is widely used to enable removal of non metallic inclusions from liquid aluminium. Its performances have been largely studied in the literature and some discrepancies remain amongst the published results. Consequently, a research program was deployed to evaluate the performances of a range of ceramic foam filters used under various conditions and to understand the inclusions capture mechanisms.

  1. Colour Studies: Clarification and Alpha-Numeric Adaptation of ...

    African Journals Online (AJOL)

    Colour studies have generated much confusion in art and design education, particularly among students of the discipline in Nigeria. This is due to the complexity of the subject matter itself, wide-range of available materials and a variety of concepts developed in its multi-disciplinarity that is not kept distinct. Therefore, this ...

  2. A numerical study on dynamics of spray jets

    Indian Academy of Sciences (India)

    The study of flow characteristics of spray jets in an injector nozzle, sol- gel process is very .... the physical properties of a fluid. .... to the nozzle is kept fixed, the walls are maintained at no slip conditions and the top of the ... represents the relationship between the axial distance from the nozzle outlet and the jet radius. Y. X.

  3. A Numerical Study of Cavitation Inception in Complex Flow Fields

    Science.gov (United States)

    2007-12-01

    report describes DYNAFLOW’s efforts over the past three years to develop and apply innovative methods to study and model the cavitation inception in...Marjollet, Fréchou, D., Fruman, D.H., Karimi, A., Kueny, J.L., Michel, J.M., La Cavitation. Mécanismes Physiques et Aspects Industrielles

  4. Automated joint space width quantification of hand and wrist joints : a proof of concept study

    NARCIS (Netherlands)

    Huo, Yinghe; Veldhuizen, Renske D; van der Heijde, Desiree M; Besselink, Nick J; Jacobs, Johannes W G; van Laar, Jacob M; Viergever, Max A; Vincken, Koen L; Lafeber, Floris P; De Hair, Maria JH

    2016-01-01

    Objective. To compare as proof of concept the sensitivity to change of automated quantification of radiographic wrist and hand joint space width (JSW) with scoring JSW according to the Sharp/van der Heijde scoring method (SHS) in two strategy groups of a treat-to-target and tight-control early

  5. A study of the effectiveness of hand protection when handling UO2 fuel pellets

    International Nuclear Information System (INIS)

    Washington, R.R.; Sullivan, D.F.

    1981-01-01

    Simple tests were performed to estimate the effectiveness of various forms of hand protection in reducing skin doses when handling UO 2 fuel pellets. Household rubber gloves (rubberized cotton) appeared to be the most effective of the varieties tested. Nylon gloves and latex finger cots were least effective. (author)

  6. Measuring hand hygiene compliance rates in different special care settings: a comparative study of methodologies

    Directory of Open Access Journals (Sweden)

    Thyago Pereira Magnus

    2015-04-01

    Conclusions: Hand hygiene compliance was reasonably high in these units, as measured by direct observation. However, a lack of correlation with results obtained by other methodologies brings into question the validity of direct observation results, and suggests that periodic audits using other methods may be needed.

  7. A five-patient satisfaction pilot study of calcium hydroxylapatite injection for treatment of aging hands.

    Science.gov (United States)

    Marmur, Ellen S; Al Quran, Hanadi; De Sa Earp, Ana Paula; Yoo, Jane Y

    2009-12-01

    The process of skin aging is not limited to the face but involves every part of the body, including the hands. A common manifestation of aging of the hands is the loss of volume, which occurs as the skin loses its subcutaneous fat. Injectable dermal fillers have surfaced as a popular method to address such deficiencies. To report the use of calcium hydroxylapatite (CaHA) to address lost volume. Five female subjects with soft tissue deficiency of the dorsa of the hands were enrolled at Mount Sinai Medical Center. A solution of CaHA with 2% lidocaine in amounts of 0.3 to 1.0 mL was injected interdigitally at each of three to five insertion sites; the sites were massaged and molded up to three times to ensure an optimal cosmetic end point. Subjects were seen for a follow-up visit after 1, 4, 16, and 24 weeks. With a single injection, all subjects reached their correction goals without requiring any touch-ups. At the 24-week visit, the subjects retained the filling effect, with no adverse events and high patient satisfaction. CaHA, a new, easily injectable, safe dermal filler, has emerged as an excellent option for soft tissue augmentation in aging hands.

  8. A Kinetic Study Using Evaporation of Different Types of Hand-Rub Sanitizers

    Science.gov (United States)

    Pinhas, Allan R.

    2010-01-01

    Alcohol-based hand-rub sanitizers are the types of products that hospital professionals use very often. These sanitizers can be classified into two major groups: those that contain a large quantity of thickener, and thus are a gel, and those that contain a small quantity of thickener, and thus remain a liquid. In an effort to create a laboratory…

  9. Numerical study of cesium effects on negative ion production in volume H-and D- ion sources

    International Nuclear Information System (INIS)

    Fukumasa, Osamu; Niitani, Eiji; Yoshino, Kyougo

    1997-01-01

    We present the results of model calculation on H - /D - isotope effects in the tandem volume source. The model includes the surface production due to cesium injection. On the electron density n e dependence of H - /D - production, we have observed an interesting phenomena. Namely D - production, i.e D - density, is higher than H - production in low n e , but in high n e H - production is higher than D - production. The atomic density plays an important role in the density inversion between H - and D - ions. (author)

  10. A Numerical Study on Hydrodynamic Interactions between Dynamic Positioning Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Doo Hwa; Lee, Sang Wook [University of Ulsan, Ulsan (Korea, Republic of)

    2017-06-15

    In this study, we conducted computational fluid dynamics (CFD) simulations for the unsteady hydrodynamic interaction of multiple thrusters by solving Reynolds averaged Navier-Stokes equations. A commercial CFD software, STAR-CCM+ was used for all simulations by employing a ducted thruster model with combination of a propeller and No. 19a duct. A sliding mesh technique was used to treat dynamic motion of propeller rotation and non-conformal hexahedral grid system was considered. Four different combinations in tilting and azimuth angles of the thrusters were considered to investigate the effects on the propulsion performance. We could find that thruster-hull and thruster-thruster interactions has significant effect on propulsion performance and further study will be required for the optimal configurations with the best tilting and relative azimuth angle between thrusters.

  11. A numerical study of blood flow using mixture theory.

    Science.gov (United States)

    Wu, Wei-Tao; Aubry, Nadine; Massoudi, Mehrdad; Kim, Jeongho; Antaki, James F

    2014-03-01

    In this paper, we consider the two dimensional flow of blood in a rectangular microfluidic channel. We use Mixture Theory to treat this problem as a two-component system: One component is the red blood cells (RBCs) modeled as a generalized Reiner-Rivlin type fluid, which considers the effects of volume fraction (hematocrit) and influence of shear rate upon viscosity. The other component, plasma, is assumed to behave as a linear viscous fluid. A CFD solver based on OpenFOAM ® was developed and employed to simulate a specific problem, namely blood flow in a two dimensional micro-channel, is studied. Finally to better understand this two-component flow system and the effects of the different parameters, the equations are made dimensionless and a parametric study is performed.

  12. Numerical study on flow and pollutant dispersion inside street canyons

    OpenAIRE

    Yunkai, Yang

    2013-01-01

    This thesis analyzes the characteristics of flow pattern and vehicle-emitted pollutant dispersion in roughness surface layer. In an urban environment, wind flow and transported-pollutant source interfere strongly with buildings and other roughness elements on the surface ground, which results in complex characteristics of flow pattern and pollutant dispersion in 3D circumstances. The present study intends to simplify the research domain and investigate the fundamental modeling problems that e...

  13. A Numerical Study on Rear-spoiler of Passenger Vehicle

    OpenAIRE

    Xu-xia Hu; Eric T. T. Wong

    2011-01-01

    The simulation of external aerodynamics is one of the most challenging and important automotive CFD applications. With the rapid developments of digital computers, CFD is used as a practical tool in modern fluid dynamics research. It integrates fluid mechanics disciplines, mathematics and computer science. In this study, two different types of simulations were made, one for the flow around a simplified high speed passenger car with a rear-spoiler and the other for the flow without a rear-spoi...

  14. Numerical study of the initial dynamics in tormac

    International Nuclear Information System (INIS)

    Aydemir, A.Y.

    1979-01-01

    Using a single fluid magnetohydrodynamic (MHD) code, we study the initial plasma dynamics in Tormac, an experimental device which attempts to confine plasma in a toroidal, two-pole cusp field. The code is in two dimensions and includes classical electrical conductivity and a constant heat conductivity. The full set of nonlinear MHD equations for the mass density, fluid velocity, temperature, the poloidal flux function, and the poloidal current function are solved using a predictor-corrector method

  15. Numerical Study of Transition of an Annular Lift Fan Aircraft

    Directory of Open Access Journals (Sweden)

    Yun Jiang

    2016-09-01

    Full Text Available The present study aimed at studying the transition of annular lift fan aircraft through computational fluid dynamics (CFD simulations. The oscillations of lift and drag, the optimization for the figure of merit, and the characteristics of drag, yawing, rolling and pitching moments in transition are studied. The results show that a two-stage upper and lower fan lift system can generate oscillations of lift and drag in transition, while a single-stage inner and outer fan lift system can eliminate the oscillations. The characteristics of momentum drag of the single-stage fans in transition are similar to that of the two-stage fans, but with the peak of drag lowered from 0.63 to 0.4 of the aircraft weight. The strategy to start transition from a negative angle of attack −21° further reduces the peak of drag to 0.29 of the weight. The strategy also reduces the peak of pitching torque, which needs upward extra thrusts of 0.39 of the weight to eliminate. The peak of rolling moment in transition needs differential upward thrusts of 0.04 of the weight to eliminate. The requirements for extra thrusts in transition lead to a total thrust–weight ratio of 0.7, which makes the aircraft more efficient for high speed cruise flight (higher than 0.7 Ma.

  16. Study of plasticity in metals by numerical simulations

    International Nuclear Information System (INIS)

    Clouet, E.

    2013-01-01

    We present a study of the plastic behaviour in metals based on the modelling of dislocation properties. Different simulation tools have been used and developed to study plasticity in structural materials, in particular metals used in the nuclear industry. In iron or zirconium alloys, plasticity is controlled at low temperature by the glide of screw dislocations. Atomistic simulations can be used to model dislocation core properties and thus to obtain a better knowledge of the mechanisms controlling dislocation glide. Such atomistic simulations need nevertheless some special care because of the long range elastic field induced by the dislocations. We have therefore developed a modelling approach relying both on atomistic simulations, using either empirical interatomic potentials or ab initio calculations, and on elasticity theory. Such an approach has been used to obtain dislocation intrinsic core properties. These simulations allowed us to describe, in iron, the variations of these core properties with the dislocation character. In zirconium, we could identity the origin of the high lattice friction and obtain a better understanding of the competition between the different glide systems. At high temperature, dislocations do not only glide but can also cross-slip or climb. This leads to a motion of the dislocations out of their glide plane which needs to be considered when modelling the plastic flow. We performed a study of dislocation climb at different scales, leading to the implementation of a dislocation climb model in dislocation dynamics simulations. (author) [fr

  17. Numerical simulation of trapped dipolar quantum gases: Collapse studies and vortex dynamics

    KAUST Repository

    Sparber, Christof; Markowich, Peter; Huang, Zhongyi

    2010-01-01

    We numerically study the three dimensional Gross-Pitaevskii equation for dipolar quantum gases using a time-splitting algorithm. We are mainly concerned with numerical investigations of the possible blow-up of solutions, i.e. collapse of the condensate, and the dynamics of vortices. © American Institute of Mathematical Sciences.

  18. Numerical study of canister filters with alternatives filter cap configurations

    Science.gov (United States)

    Mohammed, A. N.; Daud, A. R.; Abdullah, K.; Seri, S. M.; Razali, M. A.; Hushim, M. F.; Khalid, A.

    2017-09-01

    Air filtration system and filter play an important role in getting a good quality air into turbo machinery such as gas turbine. The filtration system and filter has improved the quality of air and protect the gas turbine part from contaminants which could bring damage. During separation of contaminants from the air, pressure drop cannot be avoided but it can be minimized thus helps to reduce the intake losses of the engine [1]. This study is focused on the configuration of the filter in order to obtain the minimal pressure drop along the filter. The configuration used is the basic filter geometry provided by Salutary Avenue Manufacturing Sdn Bhd. and two modified canister filter cap which is designed based on the basic filter model. The geometries of the filter are generated by using SOLIDWORKS software and Computational Fluid Dynamics (CFD) software is used to analyse and simulates the flow through the filter. In this study, the parameters of the inlet velocity are 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s. The total pressure drop produce by basic, modified filter 1 and 2 is 292.3 Pa, 251.11 Pa and 274.7 Pa. The pressure drop reduction for the modified filter 1 is 41.19 Pa and 14.1% lower compared to basic filter and the pressure drop reduction for modified filter 2 is 17.6 Pa and 6.02% lower compared to the basic filter. The pressure drops for the basic filter are slightly different with the Salutary Avenue filter due to limited data and experiment details. CFD software are very reliable in running a simulation rather than produces the prototypes and conduct the experiment thus reducing overall time and cost in this study.

  19. Study of Interaction of Reinforcement with Concrete by Numerical Methods

    Science.gov (United States)

    Tikhomirov, V. M.; Samoshkin, A. S.

    2018-01-01

    This paper describes the study of deformation of reinforced concrete. A mathematical model for the interaction of reinforcement with concrete, based on the introduction of a contact layer, whose mechanical characteristics are determined from the experimental data, is developed. The limiting state of concrete is described using the Drucker-Prager theory and the fracture criterion with respect to maximum plastic deformations. A series of problems of the theory of reinforced concrete are solved: stretching of concrete from a central-reinforced prism and pre-stressing of concrete. It is shown that the results of the calculations are in good agreement with the experimental data.

  20. Numerical studies of edge localized instabilities in tokamaks

    International Nuclear Information System (INIS)

    Wilson, H.R.; Snyder, P.B.; Huysmans, G.T.A.; Miller, R.L.

    2002-01-01

    A new computational tool, edge localized instabilities in tokamaks equilibria (ELITE), has been developed to help our understanding of short wavelength instabilities close to the edge of tokamak plasmas. Such instabilities may be responsible for the edge localized modes observed in high confinement H-mode regimes, which are a serious concern for next step tokamaks because of the high transient power loads which they can impose on divertor target plates. ELITE uses physical insight gained from analytic studies of peeling and ballooning modes to provide an efficient way of calculating the edge ideal magnetohydrodynamic stability properties of tokamaks. This paper describes the theoretical formalism which forms the basis for the code

  1. Numerical study of spherical Torus MHD equilibrium configuration

    International Nuclear Information System (INIS)

    Cheng Faying; Dong Jiaqi; Wang Aike

    2003-01-01

    Tokamak equilibrium code SWEQU has been modified so that it can be used for the MHD equilibrium study of low aspect ratio device. Evolution of plasma configuration in start-up phase and double-null divertor configuration in steady-state phase has been simulated using the modified code. Results show that the new code can be used not only to obtain the equilibrium configuration of spherical Torus in steady-state phase, but also to simulate the evolution of plasma in the start-up phase

  2. Numerical study of compressible magnetoconvection with an open transitional boundary

    International Nuclear Information System (INIS)

    Hanami, H.; Tajima, T.

    1990-08-01

    We study by computer simulation nonlinear evolution of magnetoconvection in a system with a dynamical open boundary between the convection region and corona of the sun. We study a model in which the fluid is subject to the vertical gravitation, magnetohydrodynamics (MHD), and high stratification, through an MHD code with the MacCormack-Donner cell hybrid scheme in order to well represent convective phenomena. Initially the vertical fluid flux penetrates from the convectively unstable zone at the bottom into the upper diffuse atmosphere. As the instability develops, the magnetic fields are twisted by the convection motion and the folding magnetic fields is observed. When the magnetic pressure is comparable to the thermal pressure in the upper layer of convective zone, strong flux expulsion from the convective cell interior toward the cell boundary appears. Under appropriate conditions our simulation exhibits no shock formation incurred by the fluid convected to the photosphere, in contrast to earlier works with box boundaries. The magnetic field patterns observed are those of concentrated magnetic flux tubes, accumulation of dynamo flux near the bottom boundary, pinched flux near the downdraft region, and the surface movement of magnetic flux toward the downdraft region. Many of these computationally observed features are reminiscent of solar observations of the fluid and magnetic structures of their motions

  3. Numerical Studies of Low Cycle Fatigue in Forward Extrusion Dies

    DEFF Research Database (Denmark)

    Pedersen, Thomas Ø

    2000-01-01

    of describing the elastic-plastic material behaviour under cyclic loadings is used to study the effects of different pre-stressing concepts on the accumulation of plastic strain and the development of fatigue damage. The results show, that the accumulation of plastic strain in the critical region can......Forward extrusion dies typically fail due to transverse fatigue cracks or wear. Fatigue cracks are initiated in regions where the material is subjected to repeated plastic deformations, e.g. the transition radius in a forward extrusion die, in the present work, a material model capable...... be controlled by means of the pre-stressing system or the geometry of the die insert. (C) 2000 Elsevier Science B.V. All rights reserved....

  4. Numerical study of surface plasmon enhanced nonlinear absorption and refraction.

    Science.gov (United States)

    Kohlgraf-Owens, Dana C; Kik, Pieter G

    2008-07-07

    Maxwell Garnett effective medium theory is used to study the influence of silver nanoparticle induced field enhancement on the nonlinear response of a Kerr-type nonlinear host. We show that the composite nonlinear absorption coefficient, beta(c), can be enhanced relative to the host nonlinear absorption coefficient near the surface plasmon resonance of silver nanoparticles. This enhancement is not due to a resonant enhancement of the host nonlinear absorption, but rather due to a phase shifted enhancement of the host nonlinear refractive response. The enhancement occurs at the expense of introducing linear absorption, alpha(c), which leads to an overall reduced figure of merit beta(c)/alpha(c) for nonlinear absorption. For thin (< 1 microm) composites, the use of surface plasmons is found to result in an increased nonlinear absorption response compared to that of the host material.

  5. Hand eczema

    DEFF Research Database (Denmark)

    Ibler, K.S.; Jemec, G.B.E.; Flyvholm, M.-A.

    2012-01-01

    Background. Healthcare workers are at increased risk of developing hand eczema. Objectives. To investigate the prevalence and severity of self-reported hand eczema, and to relate the findings to demographic data, occupation, medical speciality, wards, shifts, and working hours. Patients/materials......Background. Healthcare workers are at increased risk of developing hand eczema. Objectives. To investigate the prevalence and severity of self-reported hand eczema, and to relate the findings to demographic data, occupation, medical speciality, wards, shifts, and working hours. Patients...... dermatitis, younger age, male sex (male doctors), and working hours. Eighty nine per cent of subjects reported mild/moderate lesions. Atopic dermatitis was the only factor significantly related to severity. Sick leave was reported by 8% of subjects, and notification to the authorities by 12%. Conclusions...... or severity, but cultural differences between professions with respect to coping with the eczema were significant. Atopic dermatitis was related to increased prevalence and severity, and preventive efforts should be made for healthcare workers with atopic dermatitis....

  6. Hand sanitisers for reducing illness absences in primary school children in New Zealand: a cluster randomised controlled trial study protocol

    Directory of Open Access Journals (Sweden)

    Poore Marion R

    2010-01-01

    Full Text Available Abstract Background New Zealand has relatively high rates of morbidity and mortality from infectious disease compared with other OECD countries, with infectious disease being more prevalent in children compared with others in the population. Consequences of infectious disease in children may have significant economic and social impact beyond the direct effects of the disease on the health of the child; including absence from school, transmission of infectious disease to other pupils, staff, and family members, and time off work for parents/guardians. Reduction of the transmission of infectious disease between children at schools could be an effective way of reducing the community incidence of infectious disease. Alcohol based no-rinse hand sanitisers provide an alternative hand cleaning technology, for which there is some evidence that they may be effective in achieving this. However, very few studies have investigated the effectiveness of hand sanitisers, and importantly, the potential wider economic implications of this intervention have not been established. Aims The primary objective of this trial is to establish if the provision of hand sanitisers in primary schools in the South Island of New Zealand, in addition to an education session on hand hygiene, reduces the incidence rate of absence episodes due to illness in children. In addition, the trial will establish the cost-effectiveness and conduct a cost-benefit analysis of the intervention in this setting. Methods/Design A cluster randomised controlled trial will be undertaken to establish the effectiveness and cost-effectiveness of hand sanitisers. Sixty-eight primary schools will be recruited from three regions in the South Island of New Zealand. The schools will be randomised, within region, to receive hand sanitisers and an education session on hand hygiene, or an education session on hand hygiene alone. Fifty pupils from each school in years 1 to 6 (generally aged from 5 to 11 years

  7. Radiographic appearance of Ewing sarcoma of the hands and feet: report from the Intergroup Ewing Sarcoma Study

    International Nuclear Information System (INIS)

    Reinus, W.R.; Gilula, L.A.; Shirley, S.K.; Askin, F.B.; Siegal, G.P.

    1985-01-01

    Review of current data from the Intergroup Ewing Sarcoma Study (IESS) shows that Ewing sarcoma is rare in bones of the hands and feet. The 12 patients from the IESS protocols with hand or foot Ewing sarcoma are comparable to those already reported in the literature. With the exception of lesions in the calcaneus, the prognosis for disease-free survival is excellent. The radiographic features of hand and foot Ewing sarcoma are generally those of classic Ewing sarcoma: permeation, soft-tissue mass, and often, associated sclerotic reaction. However, with the exception of sclerosis, features suggesting bone reaction and slow tumor growth in these patients were distinctly uncommon compared with Ewing sarcoma in general. Apparently location of the lesion is important, since in the reported cases in the literature and in this series, lesions of the calcaneus fared poorly. The importance of this set of patients therefore relates to awareness and early recognition of an unusual appearance and location of Ewing sarcoma

  8. HAND INJURIES IN VOLLEYBALL

    NARCIS (Netherlands)

    BHAIRO, NH; NIJSTEN, MWN; VANDALEN, KC; TENDUIS, HJ

    We studied the long-term sequelae of hand injuries as a result of playing volleyball. In a retrospective study, 226 patients with injuries of the hand who were seen over a 5-year period at our Trauma Department, were investigated. Females accounted for 66 % of all injuries. The mean age was 26

  9. Numerical study of hub taper angle on podded propeller performance

    International Nuclear Information System (INIS)

    Islam, M.F.; Veitch, B.; Bose, N.; Liu, P.

    2005-01-01

    Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)

  10. Numerical study of neoclassical plasma pedestal in a tokamak geometry

    International Nuclear Information System (INIS)

    Chang, C.S.; Ku, Seunghoe; Weitzner, H.

    2004-01-01

    The fundamental properties of steep neoclassical plasma pedestals in a quiescent tokamak plasma have been investigated with a new guiding center particle code XGC: an X-point included Guiding Center code. It is shown that the width of the steepest neoclassical pedestals is similar to an experimentally observed edge pedestal width, and that a steep pedestal must be accompanied by a self-consistent negative radial electric field well. It is also shown that a steep neoclassical pedestal can form naturally at a quiescent diverted edge as the particle source from the neutral penetration (and heat flux from the core plasma) is balanced by the sharply increasing convective ion loss toward the separatrix. The steep neoclassical pedestal and the strong radial electric field well are suppressed by an anomalous diffusion coefficient of a strength appropriate to an L-mode state; nonetheless, the ExB shearing rate increases rapidly with pedestal temperature. Additionally, the present study shows that a steep pedestal at the diverted edge acts as a cocurrent parallel momentum source

  11. Nanoparticles in dilute solution : A numerical study of rotational diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Evensen, Tom Richard

    2008-06-15

    This thesis is dedicated to Brownian dynamics simulations of rotational diffusion. A rotation dynamics engine has been implemented and tested. This engine will in the future be integrated as a part of a complete Brownian dynamics simulation tool. The special case, when translational motion can be ignored, has thoroughly been studied. Two choices of generalized coordinates describing angular orientation of the particles are used. The Euler angles, which constitute the classical choice, and the Cartesian components of the rotation vector, which was recently introduced as an alternative, are being compared with regards to computational efficiency. Results from both equilibrium and non-equilibrium simulations are presented. The consistency of two new algorithms is demonstrated on systems of free rigid particles with arbitrary surface topographies. The algorithms make use of only the principal values of the rotational mobility tensor, assuming the corresponding principal axes coincide with the body-fixed coordinate system. These three scalars contain all information about the particle surface topography relevant for rotational diffusion. The calculation of the mobility tensor can be performed in a pre-calculation step, which makes the algorithm itself highly efficient. Both choices of generalized coordinates correctly reproduce theoretical predictions, but we have found that the algorithm using the Cartesian components of the rotation vector as generalized coordinates outperform its counterpart using the Euler angles by up to a factor 1000 in extreme cases. The reason for this improvement is that the algorithm using the Cartesian components of the rotation vector is free of singularities. (Author). refs. figs

  12. Numerical study of damage in unsaturated Geological and Engineered barriers

    International Nuclear Information System (INIS)

    Arson, C.; Gatmiri, B.

    2011-01-01

    The theoretical framework of a damage model dedicated to non-isothermal unsaturated porous media is presented. The damage variable is a second-order tensor, and the model is formulated in independent state variables. The behavior laws are derived from a postulated expression of Helmholtz free energy. The damaged rigidities are computed by applying the Principle of Equivalent Elastic Energy (PEEE). Internal length parameters are introduced in the expressions of liquid water and vapor conductivities, to account for cracking effects on fluid flows. The damage model has been implemented in Θ-Stock Finite Element program. The mechanical aspect of the damage model is validated by simulating a triaxial compression test on a dry isothermal brittle material. Then, a sophisticated model of nuclear waste disposal, involving two non-isothermal unsaturated porous media, is reproduced. The results obtained in elasticity are in good agreement with the results presented in the corresponding reference article. A parametric study on initial damage is then performed to assess the influence of the Excavated Damaged Zone (EDZ) on the response of the nuclear waste repository during the heating phase. The trends meet the theoretical expectations. (authors)

  13. One-dimensional long-range percolation: A numerical study

    Science.gov (United States)

    Gori, G.; Michelangeli, M.; Defenu, N.; Trombettoni, A.

    2017-07-01

    In this paper we study bond percolation on a one-dimensional chain with power-law bond probability C /rd +σ , where r is the distance length between distinct sites and d =1 . We introduce and test an order-N Monte Carlo algorithm and we determine as a function of σ the critical value Cc at which percolation occurs. The critical exponents in the range 0 values for Cc are compared with a known exact bound, while the critical exponent ν is compared with results from mean-field theory, from an expansion around the point σ =1 and from the ɛ -expansion used with the introduction of a suitably defined effective dimension deff relating the long-range model with a short-range one in dimension deff. We finally present a formulation of our algorithm for bond percolation on general graphs, with order N efficiency on a large class of graphs including short-range percolation and translationally invariant long-range models in any spatial dimension d with σ >0 .

  14. Defect-based graphene nanoribbon photodetectors: A numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Zarei, M. H.; Sharifi, M. J., E-mail: m-j-sharifi@sbu.ac.ir [Department of Electrical Engineering, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of)

    2016-06-07

    Recently, some photodetectors based on graphene have been proposed. In all of these works, current generation was carried out by separation of photo-excited carriers using an electric field, either internal or external. In this work, a new method of producing current which is based on different transmission coefficients for electrons and holes when they travel toward any of the two contacts is proposed. To this end, a single Stone–Wales defect close to one of the two contacts was used to break the channel symmetry. In order to confirm the idea, the non-equilibrium Green's function formalism in real space in conjunction with the tight binding method was used in simulations. In addition, to clarify the results, we present a classical model in which different diffusion constants are assumed for the left going and the right going carriers. Additional simulations for different positions of the defect, different lengths of the ribbon, and different bias voltages were performed, and the results are included in this study.

  15. Numerical study of multiscale compaction-initiated detonation

    Science.gov (United States)

    Gambino, J. R.; Schwendeman, D. W.; Kapila, A. K.

    2018-02-01

    A multiscale model of heterogeneous condensed-phase explosives is examined computationally to determine the course of transient events following the application of a piston-driven stimulus. The model is a modified version of that introduced by Gonthier (Combust Sci Technol 175(9):1679-1709, 2003. https://doi.org/10.1080/00102200302373) in which the explosive is treated as a porous, compacting medium at the macro-scale and a collection of closely packed spherical grains capable of undergoing reaction and diffusive heat transfer at the meso-scale. A separate continuum description is ascribed to each scale, and the two scales are coupled together in an energetically consistent manner. Following piston-induced compaction, localized energy deposition at the sites of intergranular contact creates hot spots where reaction begins preferentially. Reaction progress at the macro-scale is determined by the spatial average of that at the grain scale. A parametric study shows that combustion at the macro-scale produces an unsteady detonation with a cyclical character, in which the lead shock loses strength and is overtaken by a stronger secondary shock generated in the partially reacted material behind it. The secondary shock in turn becomes the new lead shock and the process repeats itself.

  16. Interface thermal characteristics of flip chip packages - A numerical study

    International Nuclear Information System (INIS)

    Kandasamy, Ravi; Mujumdar, A.S.

    2009-01-01

    Flip chip ball grid array (FC-BGA) packages are commonly used for high inputs/outputs (I/O) ICs; they have been proven to provide good solutions for a variety of applications to maximize thermal and electrical performance. A fundamental limitation to such devices is the thermal resistance at the top of the package, which is characterized θ JC parameter. The die-to-lid interface thermal resistance is identified as a critical issue for the thermal management of electronic packages. This paper focuses on the effect of the interface material property changes on the interface thermal resistance. The effect of package's junction to case (Theta-JC or θ JC ) thermal performance is investigated for bare die, flat lid and cup lid packages using a validated thermal model. Thermal performance of a cup or flat lid attached and bare die packages were investigated for different interface materials. Improved Theta-JC performance was observed for the large die as compared to the smaller die. Several parametric studies were carried out to understand the effects of interface bond line thickness (BLT), different die sizes, the average void size during assembly and thermal conductivity of interface materials on package thermal resistance

  17. Numerical study of sediment dynamics during hurricane Gustav

    Science.gov (United States)

    Zang, Zhengchen; Xue, Z. George; Bao, Shaowu; Chen, Qin; Walker, Nan D.; Haag, Alaric S.; Ge, Qian; Yao, Zhigang

    2018-06-01

    In this study, the coupled ocean-atmosphere-wave-and-sediment transport (COAWST) modeling system was employed to explore sediment dynamics in the northern Gulf of Mexico during hurricane Gustav in 2008. The performance of the model was evaluated quantitatively and qualitatively against in-situ and remote sensing measurements, respectively. After Gustav's landfall in coastal Louisiana, the maximum significant wave heights reached more than 8 m offshore and they decreased quickly as it moved toward the inner shelf, where the vertical stratification was largely destroyed. Alongshore currents were dominant westward on the eastern sector of the hurricane track, and offshoreward currents prevailed on the western sector. High suspended sediment concentrations (>1000 mg/l) were confined to the inner shelf at surface layers and the simulated high concentrations at the bottom layer extended to the 200 m isobaths. The stratification was restored one week after landfall, although not fully. The asymmetric hurricane winds induced stronger hydrodynamics in the eastern sector, which led to severe erosion. The calculated suspended sediment flux (SSF) was convergent to the hurricane center and the maximum SSF was simulated near the south and southeast of the Mississippi river delta. The averaged post-hurricane deposition over the Louisiana shelf was 4.0 cm, which was 3.2-26 times higher than the annual accumulation rate under normal weather conditions.

  18. Numerical studies of rock-gas flow in Yucca Mountain

    International Nuclear Information System (INIS)

    Ross, B.; Amter, S.; Lu, Ning

    1992-02-01

    A computer model (TGIF -- Thermal Gradient Induced Flow) of two-dimensional, steady-state rock-gas flow driven by temperature and humidity differences is described. The model solves for the ''fresh-water head,'' a concept that has been used in models of variable-density water flow but has not previously been applied to gas flow. With this approach, the model can accurately simulate the flows driven by small differences in temperature. The unsaturated tuffs of Yucca Mountain, Nevada, are being studied as a potential site for a repository for high-level nuclear waste. Using the TGIF model, preliminary calculations of rock-gas flow in Yucca Mountain are made for four east-west cross-sections through the mountain. Calculations are made for three repository temperatures and for several assumptions about a possible semi-confining layer above the repository. The gas-flow simulations are then used to calculate travel-time distributions for air and for radioactive carbon-14 dioxide from the repository to the ground surface

  19. Experimental and numerical studies of micro PEM fuel cell

    Science.gov (United States)

    Peng, Rong-Gui; Chung, Chen-Chung; Chen, Chiun-Hsun

    2011-10-01

    A single micro proton exchange membrane fuel cell (PEMFC) has been produced using Micro-electromechanical systems (MEMS) technology with the active area of 2.5 cm2 and channel depth of about 500 µm. A theoretical analysis is performed in this study for a novel MEMS-based design of amicro PEMFC. Themodel consists of the conservation equations of mass, momentum, species and electric current in a fully integrated finite-volume solver using the CFD-ACE+ commercial code. The polarization curves of simulation are well correlated with experimental data. Three-dimensional simulations are carried out to treat prediction and analysis of micro PEMFC temperature, current density and water distributions in two different fuel flow rates (15 cm3/min and 40 cm3/min). Simulation results show that temperature distribution within the micro PEMFC is affected by water distribution in the membrane and indicate that low and uniform temperature distribution in the membrane at low fuel flow rates leads to increased membrane water distribution and obtains superior micro PEMFC current density distribution under 0.4V operating voltage. Model predictions are well within those known for experimental mechanism phenomena.

  20. Impact of environmental olfactory cues on hand hygiene behaviour in a simulated hospital environment: a randomized study.

    Science.gov (United States)

    Birnbach, D J; King, D; Vlaev, I; Rosen, L F; Harvey, P D

    2013-09-01

    This study investigated the impact of a fresh scent on the rate of hand hygiene compliance (HHC) among novice healthcare providers. In all, 165 participants examined a standardized patient with one sample exposed to fresh scent (N = 79) and the other exposed to the standard environment (N = 86). Hand hygiene behaviours were tracked before patient contact using video surveillance. The standard environment group had an HHC rate of 51% whereas participants in the fresh scent group had a higher HHC rate of 80% (P behaviour may be subconsciously influenced by cues in the environment. © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  1. Numerical Study of Severe Accidents on Containment Venting Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Na Rae; Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong [FNC Technology Co., Yongin (Korea, Republic of); Choi, Yu Jung; Lee, Sang Won; Kim, Hyeong Taek [KHNP-CRI, Daejeon (Korea, Republic of)

    2014-10-15

    Under severe accident, the containment integrity can be challenged due to over-pressurization by steam and non-condensable gas generation. According to Seismic Probabilistic Safety Assessment (PSA) result, the late containment failure by over-pressurization has been identified as the most probable containment failure mode. In addition, the analyses of Fukushima nuclear power plant accident reveal the necessity of the proper containment depressurization to prevent the large release of the radionuclide to environment. Containment venting has been considered as an effective approach to maintain the containment integrity from over-pressurization. Basic idea of containment venting is to relieve the pressure inside of the containment by establishing a flow path to the external environment. To ensure the containment integrity under over-pressure conditions, it is crucial to conduct the containment vent in a timely manner with a sufficient discharge flow rate. It is also important to optimize the vent line size to prevent additional risk of leakage and to install at the site with limited space availability. The purpose of this study is to identify the effective venting conditions for preventing the containment over-pressurization and investigate the vent flow characteristics to minimize the consequence of the containment ventilation.. In order that, thermodynamic behavior of the containment and the discharged flow depending on different vent strategies are analyzed and compared. The representative accident scenarios are identified by reviewing the Level 2 PSA result and the sensitivity analyses with varying conditions (i.e. vent line size and vent initiation pressure) are conducted. MAAP5 model for the OPR1000 Korea nuclear power plant has been used for severe accident simulations. Containment venting can be an effective strategy to prevent the significant failure of the containment due to over-pressurization. However, it should be carefully conducted because the vented

  2. Numerical Study of Severe Accidents on Containment Venting Conditions

    International Nuclear Information System (INIS)

    Lee, Na Rae; Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong; Choi, Yu Jung; Lee, Sang Won; Kim, Hyeong Taek

    2014-01-01

    Under severe accident, the containment integrity can be challenged due to over-pressurization by steam and non-condensable gas generation. According to Seismic Probabilistic Safety Assessment (PSA) result, the late containment failure by over-pressurization has been identified as the most probable containment failure mode. In addition, the analyses of Fukushima nuclear power plant accident reveal the necessity of the proper containment depressurization to prevent the large release of the radionuclide to environment. Containment venting has been considered as an effective approach to maintain the containment integrity from over-pressurization. Basic idea of containment venting is to relieve the pressure inside of the containment by establishing a flow path to the external environment. To ensure the containment integrity under over-pressure conditions, it is crucial to conduct the containment vent in a timely manner with a sufficient discharge flow rate. It is also important to optimize the vent line size to prevent additional risk of leakage and to install at the site with limited space availability. The purpose of this study is to identify the effective venting conditions for preventing the containment over-pressurization and investigate the vent flow characteristics to minimize the consequence of the containment ventilation.. In order that, thermodynamic behavior of the containment and the discharged flow depending on different vent strategies are analyzed and compared. The representative accident scenarios are identified by reviewing the Level 2 PSA result and the sensitivity analyses with varying conditions (i.e. vent line size and vent initiation pressure) are conducted. MAAP5 model for the OPR1000 Korea nuclear power plant has been used for severe accident simulations. Containment venting can be an effective strategy to prevent the significant failure of the containment due to over-pressurization. However, it should be carefully conducted because the vented

  3. Numerical study of a water distillation system using solar energy

    International Nuclear Information System (INIS)

    Zarzoum, K.; Zhani, K.; Bacha, H. Ben

    2016-01-01

    This paper tackles an optimization approach in order to boost the fresh water production of a new design of a solar still which is located at Sfax engineering national school in Tunisia. This optimization approach is based upon the above mentioned design's improvement by coupling the conventional solar still into at a condenser, solar air and water collector and humidifier. This new concept of a distiller solar still using humidification- dehumidification processes (HD) is exploited for the desalination purpose. As a result of this work, the humidification- dehumidification processes have an essential effect in improving the solar still performance. Performance has been predicted theoretically in terms of water and inner glass cover temperatures, the inlet temperature of air and water of the new concept of distiller on water condensation rate and fresh water production. A general model based on heat and mass transfers in each component of the unit has been developed in steady dynamic regime. The developed model is used, simulating the HD system, to investigate the influence of the meteorological and operating parameters on the system productivity. The obtained set of ordinary differential equations has been converted to a set of algebraic system of equations by the functional approximation method of orthogonal collocation. The developed model is used to simulate the HD system in order to investigate the steady state behavior of each component of the unit and the entire system exposed to a variation of the entrance parameters and meteorological conditions. The obtained results were compared with those of other studies and the comparison gives a good validity of the present results

  4. Numerical study on wake characteristics of high-speed trains

    Science.gov (United States)

    Yao, Shuan-Bao; Sun, Zhen-Xu; Guo, Di-Long; Chen, Da-Wei; Yang, Guo-Wei

    2013-12-01

    Intensive turbulence exists in the wakes of high speed trains, and the aerodynamic performance of the trailing car could deteriorate rapidly due to complicated features of the vortices in the wake zone. As a result, the safety and amenity of high speed trains would face a great challenge. This paper considers mainly the mechanism of vortex formation and evolution in the train flow field. A real CRH2 model is studied, with a leading car, a middle car and a trailing car included. Different running speeds and cross wind conditions are considered, and the approaches of unsteady Reynold-averaged Navier-Stokes (URANS) and detached eddy simulation (DES) are utilized, respectively. Results reveal that DES has better capability of capturing small eddies compared to URANS. However, for large eddies, the effects of two approaches are almost the same. In conditions without cross winds, two large vortex streets stretch from the train nose and interact strongly with each other in the wake zone. With the reinforcement of the ground, a complicated wake vortex system generates and becomes strengthened as the running speed increases. However, the locations of flow separations on the train surface and the separation mechanism keep unchanged. In conditions with cross winds, three large vortices develop along the leeward side of the train, among which the weakest one has no obvious influence on the wake flow while the other two stretch to the tail of the train and combine with the helical vortices in the train wake. Thus, optimization of the aerodynamic performance of the trailing car should be aiming at reducing the intensity of the wake vortex system.

  5. Numerical study of a water distillation system using solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Zarzoum, K.; Zhani, K. [Sfax University, (Turkey); Bacha, H. Ben [Prince Sattam Bin Abdulaziz University, Alkharj (Saudi Arabia)

    2016-02-15

    This paper tackles an optimization approach in order to boost the fresh water production of a new design of a solar still which is located at Sfax engineering national school in Tunisia. This optimization approach is based upon the above mentioned design's improvement by coupling the conventional solar still into at a condenser, solar air and water collector and humidifier. This new concept of a distiller solar still using humidification- dehumidification processes (HD) is exploited for the desalination purpose. As a result of this work, the humidification- dehumidification processes have an essential effect in improving the solar still performance. Performance has been predicted theoretically in terms of water and inner glass cover temperatures, the inlet temperature of air and water of the new concept of distiller on water condensation rate and fresh water production. A general model based on heat and mass transfers in each component of the unit has been developed in steady dynamic regime. The developed model is used, simulating the HD system, to investigate the influence of the meteorological and operating parameters on the system productivity. The obtained set of ordinary differential equations has been converted to a set of algebraic system of equations by the functional approximation method of orthogonal collocation. The developed model is used to simulate the HD system in order to investigate the steady state behavior of each component of the unit and the entire system exposed to a variation of the entrance parameters and meteorological conditions. The obtained results were compared with those of other studies and the comparison gives a good validity of the present results.

  6. Effect of power-assisted hand-rim wheelchair propulsion on shoulder load in experienced wheelchair users : A pilot study with an instrumented wheelchair

    NARCIS (Netherlands)

    Kloosterman, Marieke G. M.; Buurke, Jaap H.; de Vries, Wiebe; Van der Woude, Lucas H. V.; Rietman, Johan S.

    2015-01-01

    This study aims to compare hand-rim and power-assisted hand-rim propulsion on potential risk factors for shoulder overuse injuries: intensity and repetition of shoulder loading and force generation in the extremes of shoulder motion. Eleven experienced hand-rim wheelchair users propelled an

  7. Effect of power-assisted hand-rim wheelchair propulsion on shoulder load in experienced wheelchair users: A pilot study with an instrumented wheelchair

    NARCIS (Netherlands)

    Kloosterman, Marieke; Buurke, Jaap; de Vries, W.; de Vries, W.; van der Woude, L.H.V.; Rietman, Johan Swanik

    2015-01-01

    This study aims to compare hand-rim and power-assisted hand-rim propulsion on potential risk factors for shoulder overuse injuries: intensity and repetition of shoulder loading and force generation in the extremes of shoulder motion. Eleven experienced hand-rim wheelchair users propelled an

  8. A study of cladding technology on tube wall surface by a hand-held laser torch

    International Nuclear Information System (INIS)

    Terada, Takaya; Nishimura, Akihiko; Oka, Kiyoshi; Moriyama, Taku; Matsuda, Hiroyasu

    2015-01-01

    New maintenance technique was proposed using a hand-held laser torch for aging chemical plants and power plants. The hand-held laser torch was specially designed to be able to access limited tubular space in various cases. A composite-type optical fiberscope was composed of a center fiber for beam delivery and surrounded fibers for visible image delivery. Laser irradiation on a work pieces with the best accuracy of filler wire was carried out. And, we found that the optimized wire-feed speed was 2 mm/s in laser cladding. We succeeded to make a line clad on the inner wall of 23 mm tube. This technique was discussed to be applied to the maintenance for cracks or corrosions of tubes in various harsh environments. (author)

  9. Loss of productivity due to neck/shoulder symptoms and hand/arm symptoms: Results from the PROMO-study

    NARCIS (Netherlands)

    Heuvel, S.G. van den; IJmker, S.; Blatter, B.M.; Korte, E.M. de

    2007-01-01

    Introduction: The objective of the present study is to describe the extent of productivity loss among computer workers with neck/shoulder symptoms and hand/arm symptoms, and to examine associations between pain intensity, various physical and psychosocial factors and productivity loss in computer

  10. Assessing the gaming experience of an applied game for rehabilitation of the arm and hand function : A feasibility study

    NARCIS (Netherlands)

    Kottink, Anke I.R.; Prange-Lasonder, Gerdienke B.; Rietman, Johan S.; Buurke, Jaap H.; Ibánez, Jaíme; González-Vargas, José; Azorín, José María; Akay, Metin; Pons, José Luis

    2017-01-01

    The present pilot study assessed the feasibility, in terms of gaming experience, of using a first prototype of a self-developed mixed-reality system for rehabilitation of the arm and hand function. Results showed that the hybrid game approach is well accepted by Cerebral Palsy children and adults

  11. Using the Hand Laterality Judgement Task to assess motor imagery : a study of practice effects in repeated measurements

    NARCIS (Netherlands)

    Boonstra, Anne M.; de Vries, Sjoerd J.; Veenstra, Evelien; Tepper, Marga; Feenstra, Wya; Otten, Egbert

    The aim of this study was to determine whether there is a practice effect on the Hand Laterality Judgement Task (HLJT). The HLJT task is a mental rotation task that can be used to assess motor imagery ability in stroke patients. Thirty-three healthy individuals performed the HLJT and two control

  12. Using the Hand Laterality Judgement Task to Assess Motor Imagery: A Study of Practice Effects in Repeated Measurements

    Science.gov (United States)

    Boonstra, Anne M.; de Vries, Sjoerd J.; Veenstra, Evelien; Tepper, Marga; Feenstra, Wya; Otten, Egbert

    2012-01-01

    The aim of this study was to determine whether there is a practice effect on the Hand Laterality Judgement Task (HLJT). The HLJT task is a mental rotation task that can be used to assess motor imagery ability in stroke patients. Thirty-three healthy individuals performed the HLJT and two control tasks twice at a 3-week interval. Differences in the…

  13. Effects of Gloves, Temperature and Their Interaction on Finger, Hand, and Arm Blood Flow and Skin Temperature: A Pilot Study

    Science.gov (United States)

    Hallbech, M. Susan

    1996-01-01

    The objective of this study is to investigate the effects of cold only, commercially available gloves only, and the combination of gloves and cold on the blood flow and surface (skin) temperature of the medial and proximal phalanxes of digit 3, the metacarpal region of the hand, and the forearm.

  14. Using picture analysis as a measurement tool for measuring edema in the hand: a study about usability and functionality

    NARCIS (Netherlands)

    Tijssen, R.; Lukkien, C.C.; Peters, P.J.F.

    2016-01-01

    he purpose of this study was to determine whether picture analysis can be used for detecting change of edema in the hand and whether picture analysis can be an added value in the patient’s treatment. It was analyzed which factors are important for detecting change of edema and if this can be

  15. Effects of Smoking on Hand Tendon Repair: Scientific Study & Literature Review

    OpenAIRE

    Samona J; Samona S; Gilin M; Carwile D; Persons S; AG Dass

    2017-01-01

    Purpose: The clinical effect of smoking on after tendon repair in smokers vs non-smokers was investigated, via exploring effects on flexor and tendon repair, and incidence of wound complications. Methods: Retrospective review of patients treated by 1 orthopedic surgeon, fellowship trained in hand surgery, and 3 occupational therapists working together in 1 physical therapy institution. 56 patients (20 smokers and 36 non-smokers) with acute traumatic tendon lacerations, fixed via direct (end-t...

  16. The dynamics of sensorimotor cortical oscillations during the observation of hand movements: an EEG study.

    Directory of Open Access Journals (Sweden)

    Pietro Avanzini

    Full Text Available BACKGROUND: The observation of action done by others determines a desynchronization of the rhythms recorded from cortical central regions. Here, we examined whether the observation of different types of hand movements (target directed, non-target directed, cyclic and non-cyclic elicits different EEG cortical temporal patterns. METHODOLOGY: Video-clips of four types of hand movements were shown to right-handed healthy participants. Two were target directed (grasping and pointing motor acts; two were non-target directed (supinating and clenching movements. Grasping and supinating were performed once, while pointing and clenching twice (cyclic movements. High-density EEG was recorded and analyzed by means of wavelet transform, subdividing the time course in time bins of 200 ms. The observation of all presented movements produced a desynchronization of alpha and beta rhythms in central and parietal regions. The rhythms desynchronized as soon as the hand movement started, the nadir being reached around 700 ms after movement onset. At the end of the movement, a large power rebound occurred for all bands. Target and non-target directed movements produced an alpha band desynchronization in the central electrodes at the same time, but with a stronger desynchronization and a prolonged rebound for target directed motor acts. Most interestingly, there was a clear correlation between the velocity profile of the observed movements and beta band modulation. SIGNIFICANCE: Our data show that the observation of motor acts determines a modulation of cortical rhythm analogous to that occurring during motor act execution. In particular, the cortical motor system closely follows the velocity of the observed movements. This finding provides strong evidence for the presence in humans of a mechanism (mirror mechanism mapping action observation on action execution motor programs.

  17. Direct magnification radiography of the hand for the study of erosions in reumathoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Orzincolo, C; Corcione, S; Campanati, A; Scutellari, P N; Bonari, L R

    1986-01-01

    Plain films and direct magnification radiographs of the hands were performed in 34 patients affected by rheumatoid arthritis, using mammographic x-ray tube, achieved with 0.1 mm microfocus, and 1.85 x magnification factor. Direct magnification radiography has provided essential or useful diagnostic data in 44% of cases, particularly in recognizing early skeletal erosions. Nevertheless direct magnification radiography must be used only in those cases in which traditional mammographic techniques do not supply sactisfactory results.

  18. Study on Factors of Favorable Wet Cotton Hand Towels “Oshibori”

    Science.gov (United States)

    Soeta, Yasuhiro; Kitamoto, Takuma; Hasegawa, Hiroshi; Kasuga, Masao

    In the present study, we evaluated important factors of the feelings of comfort associated with wet cotton hand towels, or oshibori. First, the following adjectives were extracted as words used to evaluate the characteristics of the oshibori: “large,” “pretty,” “comfortable,” “high-grade,” “shapely,” “soft,” “favorite,” “thick,” “clean,” “moist,” “luxurious,” “heavy,” “strong,” “safe,” “good-touch,” and “rare.” We then conducted a subjective evaluation of 25 kinds of oshibori of various sizes and thicknesses. Forty males and twenty-four females, ranging in age from their twenties to fifties, participated in the experiment. Each subject evaluated the oshibori by grading them from one to five based on the extracted descriptive characteristics. Factor analysis was conducted on the experimental results and the following three factors were extracted; the first factor defined as “dignity factor,” the second factor defined as “preference factor,” and the third factor defined as “touch factor.” The score for dignity increased as the size of the oshibori increased. The score for preference was high when the size of the oshibori was between 25 cm × 25 cm and 30 cm × 30 cm. These results suggest that subjects felt high-class if the size of the oshibori was greater than 30 cm × 30 cm, but subjects most preferred oshibori that were between 25 cm × 25 cm and 30 cm × 30 cm. No notable trend was found between the thickness of oshibori and the three factors. We then analyzed the experimental data focusing on the following viewpoints; “gender” and “generation.” of the subjects, and discussed how these factors effected on the feelings of oshibori using the Mann-Whitney U test and the Kruskal-Wallis H test. The analyzed results show that the female subjects tended to evaluate more highly on the evaluation words of “thick,” “moist,” and “heavy,” that the evaluations of “large,”

  19. Development of numerical processing in children with typical and dyscalculic arithmetic skills—a longitudinal study

    Science.gov (United States)

    Landerl, Karin

    2013-01-01

    Numerical processing has been demonstrated to be closely associated with arithmetic skills, however, our knowledge on the development of the relevant cognitive mechanisms is limited. The present longitudinal study investigated the developmental trajectories of numerical processing in 42 children with age-adequate arithmetic development and 41 children with dyscalculia over a 2-year period from beginning of Grade 2, when children were 7; 6 years old, to beginning of Grade 4. A battery of numerical processing tasks (dot enumeration, non-symbolic and symbolic comparison of one- and two-digit numbers, physical comparison, number line estimation) was given five times during the study (beginning and middle of each school year). Efficiency of numerical processing was a very good indicator of development in numerical processing while within-task effects remained largely constant and showed low long-term stability before middle of Grade 3. Children with dyscalculia showed less efficient numerical processing reflected in specifically prolonged response times. Importantly, they showed consistently larger slopes for dot enumeration in the subitizing range, an untypically large compatibility effect when processing two-digit numbers, and they were consistently less accurate in placing numbers on a number line. Thus, we were able to identify parameters that can be used in future research to characterize numerical processing in typical and dyscalculic development. These parameters can also be helpful for identification of children who struggle in their numerical development. PMID:23898310

  20. Development of numerical processing in children with typical and dyscalculic arithmetic skills – a longitudinal study

    Directory of Open Access Journals (Sweden)

    Karin eLanderl

    2013-07-01

    Full Text Available Numerical processing has been demonstrated to be closely associated with arithmetic skills, however, our knowledge on the development of the relevant cognitive mechanisms is limited. The present longitudinal study investigated the developmental trajectories of numerical processing in 42 children with age-adequate arithmetic development and 41 children with dyscalculia over a two-year period from beginning of Grade 2, when children were 7;6 years old, to beginning of Grade 4. A battery of numerical processing tasks (dot enumeration, non-symbolic and symbolic comparison of one- and two-digit numbers, physical comparison, number line estimation was given five times during the study (beginning and middle of each school year. Efficiency of numerical processing was a very good indicator of development in numerical processing while within-task effects remained largely constant and showed low long-term stability before middle of Grade 3. Children with dyscalculia showed less efficient numerical processing reflected in specifically prolonged response times. Importantly, they showed consistently larger slopes for dot enumeration in the subitizing range, an untypically large compatibility effect when processing two-digit numbers, and they were consistently less accurate in placing numbers on a number line. Thus, we were able to identify parameters that can be used in future research to characterize numerical processing in typical and dyscalculic development. These parameters can also be helpful for identification of children who struggle in their numerical development.

  1. Coordination of hand shape.

    Science.gov (United States)

    Pesyna, Colin; Pundi, Krishna; Flanders, Martha

    2011-03-09

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

  2. Wide Awake Hand Surgery.

    Science.gov (United States)

    Lied, Line; Borchgrevink, Grethe E; Finsen, Vilhjalmur

    2017-09-01

    "Wide awake hand surgery", where surgery is performed in local anaesthesia with adrenaline, without sedation or a tourniquet, has become widespread in some countries. It has a number of potential advantages and we wished to evaluate it among our patients. All 122 patients treated by this method during one year were evaluated by the surgeons and the patients on a numerical scale from 0 (best/least) to 10 (worst/most). Theatre time was compared to that recorded for a year when regional or general anaesthesia had been used. The patients' mean score for the general care they had received was 0.1 (SD 0.6), for pain during lidocaine injection 2.4 (SD 2.2), for pain during surgery 0.9 (SD 1.5), and for other discomfort during surgery 0.5 (SD 1.4). Eight reported that they would want general anaesthesia if they were to be operated again. The surgeons' mean evaluation of bleeding during surgery was 1.6 (SD 1.8), oedema during surgery 0.4 (SD 1.1), general disadvantages with the method 1.0 (SD 1.6) and general advantages 6.5 (SD 4.3). The estimation of advantages was 9.9 (DS 0.5) for tendon suture. 28 patients needed intra-operative additional anaesthesia. The proportion was lower among trained hand surgeons and fell significantly during the study period. Non-surgical theatre time was 46 (SD 15) minutes during the study period and 55 (SD 22) minutes during the regional/general period (p theatre.

  3. Effects of hand-training in persons with myotonic dystrophy type 1--a randomised controlled cross-over pilot study.

    Science.gov (United States)

    Aldehag, Anna; Jonsson, Hans; Lindblad, Jan; Kottorp, Anders; Ansved, Tor; Kierkegaard, Marie

    2013-10-01

    To investigate the effects of a hand-training programme on grip, pinch and wrist force, manual dexterity and activities of daily living, in adults with myotonic dystrophy type 1 (DM1). In this randomised controlled trial with a crossover design, 35 adults with DM1 were, after stratification for grip force, assigned by lot to two groups. Group A started with 12 weeks of hand training, while group B had no intervention. After a wash-out period of 12 weeks, where none received training, the order was reversed. The Grippit® was used as primary outcome measure and the hand-held Microfet2™ myometer, the Purdue Pegboard, the Canadian Occupational Performance Measure (COPM) and the Assessment of Motor and Process Skills (AMPS) were secondary outcome measures. Assessments were performed before and after training and control periods, i.e. four times altogether. Ten persons dropped out and 13 had acceptable adherence. Intention-to-treat analyses revealed significant intervention effects for isometric wrist flexor force (p = 0.048), and for COPM performance (p = 0.047) and satisfaction (p = 0.027). On an individual level, improvements were in general showed after a training period. The hand-training programme had positive effects on wrist flexor force and self-perception of occupational performance, and of satisfaction with performance. No evident detrimental effects were shown. Myotonic dystrophy type 1 (DM1) is a slowly progressive neuromuscular disease characterised by myotonia and muscle weakness and wasting. People with DM1 are often concerned about their ability to carry out ADL and to participate in, e.g. work, sports and hobbies when they gradually become weaker. This pilot study showed that a hand-training programme improved wrist flexor force and self-perception and satisfaction of occupational performance. Resistance training of hand muscles with a silicon-based putty can be a therapy option for people with DM1 in clinical practise.

  4. Genetic influences on hand osteoarthritis in Finnish women--a replication study of candidate genes.

    Directory of Open Access Journals (Sweden)

    Satu Hämäläinen

    Full Text Available OBJECTIVES: Our aims were to replicate some previously reported associations of single nucleotide polymorphisms (SNPs in five genes (A2BP1, COG5, GDF5, HFE, ESR1 with hand osteoarthritis (OA, and to examine whether genes (BCAP29, DIO2, DUS4L, DVWA, HLA, PTGS2, PARD3B, TGFB1 and TRIB1 associated with OA at other joint sites were associated with hand OA among Finnish women. DESIGN: We examined the bilateral hand radiographs of 542 occupationally active Finnish female dentists and teachers aged 45 to 63 and classified them according to the presence of OA by using reference images. Data regarding finger joint pain and other risk factors were collected using a questionnaire. We defined two hand OA phenotypes: radiographic OA in at least three joints (ROA and symptomatic DIP OA. The genotypes were determined by PCR-based methods. In statistical analysis, we used SNPStats software, the chi-square test and logistic regression. RESULTS: Of the SNPs, rs716508 in A2BP1 was associated with ROA (OR = 0.7, 95% CI 0.5-0.9 and rs1800470 in TGFB1 with symptomatic DIP OA (1.8, 1.2-2.9. We found an interaction between ESR1 (rs9340799 and occupation: teachers with the minor allele were at an increased risk of symptomatic DIP OA (2.8, 1.3-6.5. We saw no association among the dentists. We also found that the carriage of the COG5 rs3757713 C allele increased the risk of ROA only among women with the BCAP29 rs10953541 CC genotype (2.6; 1.1-6.1. There was also a suggestive interaction between the HFE rs179945 and the ESR1 rs9340799, and the carriage of the minor allele of either of these SNPs was associated with an increased risk of symptomatic DIP OA (2.1, 1.3-2.5. CONCLUSIONS: Our results support the earlier findings of A2BP1 and TBGF1 being OA susceptibility genes and provide evidence of a possible gene-gene interaction in the genetic influence on hand OA predisposition.

  5. Numerical study on anaerobic digestion of fruit and vegetable waste: Biogas generation

    Science.gov (United States)

    Wardhani, Puteri Kusuma; Watanabe, Masaji

    2016-02-01

    The study provides experimental results and numerical results concerning anaerobic digestion of fruit and vegetable waste. Experiments were carried out by using batch floating drum type digester without mixing and temperature setting. The retention time was 30 days. Numerical results based on Monod type model with influence of temperature is introduced. Initial value problems were analyzed numerically, while kinetic parameters were analyzed by using trial error methods. The numerical results for the first five days seems appropriate in comparison with the experimental outcomes. However, numerical results shows that the model is inappropriate for 30 days of fermentation. This leads to the conclusion that Monod type model is not suitable for describe the mixture degradation of fruit and vegetable waste and horse dung.

  6. A numerical study on manoeuvrability of wind turbine installation vessel using OpenFOAM

    Directory of Open Access Journals (Sweden)

    Sungwook Lee

    2015-05-01

    Full Text Available In this study, a numerical prediction method on manoeuvrability of Wind Turbine Installation Vessel (WTIV is presented. Planar Motion Mechanism (PMM captive test for the bare hull of WTIV is carried out in the model basin and compared with the numerical results using RANS simulation based on Open-source Field Operation And Manipulation (OpenFOAM calculation to validate the developed method. The manoeuvrability of WTIV with skeg and/or without skeg is investigated using the numerical approach along with the captive model test. In the numerical calculations, the dynamic stability index which indicates the course keeping ability is evaluated and compared for three different hull configurations i.e. bare hull and other two hulls with center skeg and twin skeg. This paper proves that the numerical approach using RANS simulation can be readily applied to estimate the manoeuvrability of WTIV at the initial design stage.

  7. Research status and some results of numerical system to study regional environment: SPEEDI-MP

    International Nuclear Information System (INIS)

    Chino, Masamichi

    2004-01-01

    Research status and some results of 'Numerical system to study regional environment: SPEEDI-MP', which reproduces circulations of materials in the atmospheric, oceanic and terrestrial environments, are introduced. The purpose of this system are the development of various environmental models, the connection of atmospheric, oceanic and terrestrial models and the construction of research bases for numerical environmental studies. In addition to the accurate prediction of environmental behavior of radionuclides, the system has been applied to the non-nuclear fields, e.g., numerical analysis of environmental effects to volcanic gases from Miyake Jima, real-time prediction of the migration of rice planthoppers from Eastern Asia. (author)

  8. Experimental and numerical study of the mechanical behaviour modelling of a metal-ceramic composite: MoTiC30%

    International Nuclear Information System (INIS)

    Cedat, D.

    2008-11-01

    In the scope of refractory materials development for structural applications in the core of the future nuclear reactors, several studies have been developed. The aim of this work is to increase the knowledge of the mechanical behaviour and the damage of the ceramic-metal composite Mo(TiC)x% under the temperature range [25-700 C]. The identification of the third phase, formed by diffusion during the sintering step was identified by microstructural characterization. Experimental study also revealed the percolation of the ceramic particles through the structure. Mechanical tests highlight the main characteristics of the material: the macroscopic behaviour depends on the strain rate on the first hand and the temperature on the other hand. These mechanisms are attributed to the thermally activated behaviour of molybdenum. Simulations have been made on several microstructures considering elastic-brittle inclusion in a viscoelastic matrix. A polycrystalline model was used to simulate the evolution of the mechanical behaviour of the composite. The numerical aggregate, used for the simulation, was built from a 3D reconstruction technique thanks to acquisition of FIB/EBSD/SEM data. (author)

  9. Neuromarkers of Post-Traumatic Stress Disorder (PTSD) in a patient after bilateral hand amputation - ERP case study.

    Science.gov (United States)

    Chrapusta, Anna; Kropotov, Juri D; Pąchalska, Maria

    2017-06-08

    Introduction. There is a lack in the worldwide literature of reports on the Neuromarkers of Post-Traumatic Stress Disorder (PTSD) in patients after bilateral hand amputation The aim of this study was to test a hypothesis regarding developing Post-Traumatic Stress Disorder (PTSD) in a patient after bilateral hand amputation with the use of Event Related Potentials (ERPs). On the basis of previous research, the amplitudes of P3 ERP components elicited in the cued GO/NOGO tasks have been chosen as candidates for neuromarkers of PTSD. Case study. A 24-year-old patient had undergone bilateral hand amputation 12 months previously. The patient was repeatedly operated on (he had undergone successful bilateral hand replantation) and despite the severity of the injuries, he recovered. However, the patient complained of flashbacks, anxiety and sleep difficulties. Specialist tests showed the presence of PTSD. The patient participated in the cued GO/NOGO task (Kropotov, 2009) with recording 19-channel EEG. P3 GO and NOGO waves in this task were found to be significantly smaller, in comparison to a group of healthy control subjects of the same age (N=23) taken from the HBI normative database (https://www.hbimed.com/). This observed pattern of ERP waves in the patient corresponds to the pattern found in PTSD patients. Conclusions. ERPs in a GO/NOGO task can be used in the assessment of the functional brain changes induced by chronic PTSD.

  10. Numerical study of the grain growth and the thermal properties of ceramics

    International Nuclear Information System (INIS)

    Shahtahmasebi, N.; Shariaty ghleno, A.M.; Hosaini, M.

    2000-04-01

    The physical properties of ceramics strongly depends on the grain size, which itself depends on the sintering process. In this work we propose a model for sintering based on the gross features known experimental and the preform numerical study

  11. Numerical Study of the Critical Impact Velocity in Shear. Appendix Number 1

    National Research Council Canada - National Science Library

    Klosak, M

    1996-01-01

    .... A numerical study of impact shearing of a layer has been performed by the FE code ABAQUS. It was intended to verify available experimental results for VAR 4340 steel 52 HRC, obtained by direct...

  12. A numerical study of three-dimensional droplets spreading on chemically patterned surfaces

    KAUST Repository

    Zhong, Hua; Wang, Xiao-Ping; Sun, Shuyu

    2016-01-01

    We study numerically the three-dimensional droplets spreading on physically flat chemically patterned surfaces with periodic squares separated by channels. Our model consists of the Navier-Stokes-Cahn-Hilliard equations with the generalized Navier

  13. Patient Safety Culture and the Ability to Improve: A Proof of Concept Study on Hand Hygiene.

    Science.gov (United States)

    Caris, Martine G; Kamphuis, Pim G A; Dekker, Mireille; de Bruijne, Martine C; van Agtmael, Michiel A; Vandenbroucke-Grauls, Christina M J E

    2017-11-01

    OBJECTIVE To investigate whether the safety culture of a hospital unit is associated with the ability to improve. DESIGN Qualitative investigation of safety culture on hospital units following a before-and-after trial on hand hygiene. SETTING VU University Medical Center, a tertiary-care hospital in the Netherlands. METHODS With support from hospital management, we implemented a hospital-wide program to improve compliance. Over 2 years, compliance was measured through direct observation, twice before, and 4 times after interventions. We analyzed changes in compliance from baseline, and selected units to evaluate safety culture using a positive deviance approach: the hospital unit with the highest hand hygiene compliance and 2 units that showed significant improvement (21% and 16%, respectively) were selected as high performing. Another 2 units showed no improvement and were selected as low performing. A blinded, independent observer conducted interviews with unit management, physicians, and nurses, based on the Hospital Survey on Patient Safety Culture. Safety culture was categorized as pathological (lowest level), reactive, bureaucratic, proactive, or generative (highest level). RESULTS Overall, 3 units showed a proactive or generative safety culture and 2 units had bureaucratic or pathological safety cultures. When comparing compliance and interview results, high-performing units showed high levels of safety culture, while low-performing units showed low levels of safety culture. CONCLUSIONS Safety culture is associated with the ability to improve hand hygiene. Interventions may not be effective when applied in units with low levels of safety culture. Although additional research is needed to corroborate our findings, the safety culture on a unit can benefit from enhancement strategies such as team-building exercises. Strengthening the safety culture before implementing interventions could aid improvement and prevent nonproductive interventions. Infect Control

  14. The experience of living with a traumatic hand injury in a rural and remote location: an interpretive phenomenological study.

    Science.gov (United States)

    Kingston, Gail A; Judd, Dr Jenni; Gray, Marion A

    2014-01-01

    The aim of this research study was to gain an understanding of how rural and remote residents in North Queensland, Australia, engaged in work, activities of daily living tasks and social activities following a traumatic hand injury. Findings from a previous retrospective survey with these participants revealed that patients experienced difficulties such as pain for many years after their injury; however, because of the survey methodology, the voices of participants were not heard. This study contributes to a larger project that seeks to propose a model of service delivery to rural and remote residents who have sustained a traumatic injury. Utilising an interpretive phenomenological research design, data were gathered through in-depth, semistructured interviews. Fifteen participants were recruited into this study and questions were designed to explore the experience of having a traumatic hand injury in rural and remote areas of North Queensland. The thematic analysis indicated five major themes: injury and impairment, pain, occupation and activity, and resilience. Participants reported that having a hand injury often caused further injury due to the impairment. The pain experienced could be 'all consuming' yet participants reported 'pushing through' this pain to complete daily tasks. Participants reported that they would 'go mad' if they did not work and highlighted the importance of activity in their recovery. Participants felt grateful at having their hand and thought towards the future. Being self-reliant was important but they were willing to accept support from others when needed. Incorporating activity and occupation in rehabilitation programs as opposed to focusing on strict protocols is an important consideration in the recovery process of rural and remote residents. In particular, engaging in activity and occupation was an important part of managing the pain associated with the hand trauma. This research also found that participants demonstrated resilient

  15. Negotiating Left-Hand and Right-Hand Bends: A Motorcycle Simulator Study to Investigate Experiential and Behaviour Differences Across Rider Groups

    Science.gov (United States)

    Crundall, Elizabeth; Crundall, David; Stedmon, Alex W.

    2012-01-01

    Why do motorcyclists crash on bends? To address this question we examined the riding styles of three groups of motorcyclists on a motorcycle simulator. Novice, experienced and advanced motorcyclists navigated a series of combined left and right bends while their speed and lane position were recorded. Each rider encountered an unexpected hazard on both a left- and right-hand bend section. Upon seeing the hazards, all riders decreased their speed before steering to avoid the hazard. Experienced riders tended to follow more of a racing line through the bends, which resulted in them having to make the most severe changes to their position to avoid a collision. Advanced riders adopted the safest road positions, choosing a position which offered greater visibility through the bends. As a result, they did not need to alter their road position in response to the hazard. Novice riders adopted similar road positions to experienced riders on the left-hand bends, but their road positions were more similar to advanced riders on right-hand bends, suggesting that they were more aware of the risks associated with right bends. Novice riders also adopted a safer position on post-hazard bends whilst the experienced riders failed to alter their behaviour even though they had performed the greatest evasive manoeuvre in response to the hazards. Advanced riders did not need to alter their position as their approach to the bends was already optimal. The results suggest that non-advanced riders were more likely to choose an inappropriate lane position than an inappropriate speed when entering a bend. Furthermore, the findings support the theory that expertise is achieved as a result of relearning, with advanced training overriding ‘bad habits’ gained through experience alone. PMID:22253845

  16. Shape-estimation of human hand using polymer flex sensor and study of its application to control robot arm

    International Nuclear Information System (INIS)

    Lee, Jin Hyuck; Kim, Dae Hyun

    2015-01-01

    Ultrasonic inspection robot systems have been widely researched and developed for the real-time monitoring of structures such as power plants. However, an inspection robot that is operated in a simple pattern has limitations in its application to various structures in a plant facility because of the diverse and complicated shapes of the inspection objects. Therefore, accurate control of the robot is required to inspect complicated objects with high-precision results. This paper presents the idea that the shape and movement information of an ultrasonic inspector's hand could be profitably utilized for the accurate control of robot. In this study, a polymer flex sensor was applied to monitor the shape of a human hand. This application was designed to intuitively control an ultrasonic inspection robot. The movement and shape of the hand were estimated by applying multiple sensors. Moreover, it was successfully shown that a test robot could be intuitively controlled based on the shape of a human hand estimated using polymer flex sensors.

  17. Alcohol-based instant hand sanitizer use in military settings: a prospective cohort study of Army basic trainees.

    Science.gov (United States)

    Mott, Peter J; Sisk, Brian W; Arbogast, James W; Ferrazzano-Yaussy, Cristina; Bondi, Cara A M; Sheehan, James J

    2007-11-01

    We investigated the impact of a customized alcohol-based instant hand sanitizer hand-hygiene regimen in an Army basic training setting. The entire population at the U.S. Army Field Artillery Training Center, Fort Sill, Oklahoma, participated in the 13-week prospective cohort study between January 18, 2005 and April 18, 2005. Two training battalions were randomly assigned to the control group, one to the primary intervention group (customized Purell Instant Hand Sanitizer regimen, education, reinforcement) and one to the secondary intervention group (customized Purell Instant Hand Sanitizer regimen). When compared to the control group, intervention groups experienced 40% less respiratory illness (p < 0.001), 48% less gastrointestinal illness (p < 0.02), 44% less lost training time (p < 0.001), and 31% fewer health care encounters (p < 0.001). These findings suggest that this intervention is capable of significantly reducing illness in this setting and has the potential to help reduce absenteeism in the military workforce as a whole.

  18. Shape-estimation of human hand using polymer flex sensor and study of its application to control robot arm

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hyuck; Kim, Dae Hyun [Seoul National University of Technology, Seoul (Korea, Republic of)

    2015-02-15

    Ultrasonic inspection robot systems have been widely researched and developed for the real-time monitoring of structures such as power plants. However, an inspection robot that is operated in a simple pattern has limitations in its application to various structures in a plant facility because of the diverse and complicated shapes of the inspection objects. Therefore, accurate control of the robot is required to inspect complicated objects with high-precision results. This paper presents the idea that the shape and movement information of an ultrasonic inspector's hand could be profitably utilized for the accurate control of robot. In this study, a polymer flex sensor was applied to monitor the shape of a human hand. This application was designed to intuitively control an ultrasonic inspection robot. The movement and shape of the hand were estimated by applying multiple sensors. Moreover, it was successfully shown that a test robot could be intuitively controlled based on the shape of a human hand estimated using polymer flex sensors.

  19. Feasibility and efficacy of a robotic device for hand rehabilitation in hemiplegic stroke patients: a randomized pilot controlled study.

    Science.gov (United States)

    Vanoglio, Fabio; Bernocchi, Palmira; Mulè, Chiara; Garofali, Francesca; Mora, Chiara; Taveggia, Giovanni; Scalvini, Simonetta; Luisa, Alberto

    2017-03-01

    The purpose of the study was to evaluate the feasibility and efficacy of robot-assisted hand rehabilitation in improving arm function abilities in sub-acute hemiplegic patients. Randomized controlled pilot study. Inpatient rehabilitation centers. Thirty hemiplegic stroke patients (Ashworth spasticity index hand training with Gloreha, a hand rehabilitation glove that provides computer-controlled, repetitive, passive mobilization of the fingers, with multisensory feedback. Patients in the CG received the same amount of time in terms of conventional hand rehabilitation. Hand motor function (Motricity Index, MI), fine manual dexterity (Nine Hole Peg Test, NHPT) and strength (Grip and Pinch test) were measured at baseline and after rehabilitation, and the differences, (Δ) mean(standard deviation), compared between groups. Results Twenty-seven patients concluded the program: 14 in the TG and 13 in the CG. None of the patients refused the device and only one adverse event of rheumatoid arthritis reactivation was reported. Baseline data did not differ significantly between the two groups. In TG, ΔMI 23(16.4), ΔNHPT 0.16(0.16), ΔGRIP 0.27(0.23) and ΔPINCH 0.07(0.07) were significantly greater than in CG, ΔMI 5.2(9.2), ΔNHPT 0.02(0.07), ΔGRIP 0.03(0.06) and ΔPINCH 0.02(0.03)] ( p=0.002, p=0.009, p=0.003 and p=0.038, respectively). Gloreha Professional is feasible and effective in recovering fine manual dexterity and strength and reducing arm disability in sub-acute hemiplegic patients.

  20. Methodology for designing and manufacturing complex biologically inspired soft robotic fluidic actuators: prosthetic hand case study.

    Science.gov (United States)

    Thompson-Bean, E; Das, R; McDaid, A

    2016-10-31

    We present a novel methodology for the design and manufacture of complex biologically inspired soft robotic fluidic actuators. The methodology is applied to the design and manufacture of a prosthetic for the hand. Real human hands are scanned to produce a 3D model of a finger, and pneumatic networks are implemented within it to produce a biomimetic bending motion. The finger is then partitioned into material sections, and a genetic algorithm based optimization, using finite element analysis, is employed to discover the optimal material for each section. This is based on two biomimetic performance criteria. Two sets of optimizations using two material sets are performed. Promising optimized material arrangements are fabricated using two techniques to validate the optimization routine, and the fabricated and simulated results are compared. We find that the optimization is successful in producing biomimetic soft robotic fingers and that fabrication of the fingers is possible. Limitations and paths for development are discussed. This methodology can be applied for other fluidic soft robotic devices.

  1. The defence technique in Tai Chi Push Hands: a case study.

    Science.gov (United States)

    Chen, Hui-Chuan; Cheng, Kuang-You B; Liu, Yu-Jen; Chiu, Hung-Ta; Cheng, Kuang-Yu

    2010-12-01

    Developed from traditional Chinese martial arts, Tai Chi exercise includes different forms and interactive Push Hands but biomechanical analyses have focused on the former only. To analyse the techniques of Push Hands, an experienced master was asked to defend pushing by four opponents. Movements were videotaped and digitized using a motion analysis system. Surface electrodes were used to record the electromyographic activity of ten muscle groups. Two force plates were used to measure the ground reaction force on each foot. Inexperienced individuals performed the same procedure to serve as the control group. The results indicate that the master adopted a postural adjustment to maintain balance. A clear shift of body weight from the front to the rear foot and mediolateral displacement of the centre of gravity was observed. Low electromyographic activity was observed in the upper body muscle groups, while high electromyographic activity was observed in the right rectus femoris and very high activity in the left rectus femoris during the defence. All inexperienced participants lost their balance in resisting pushing. It is concluded that the Tai Chi defensive technique includes a subtle postural adjustment that slightly changes the pushing force direction, and allows the rear leg to resist the incoming force.

  2. Apical extrusion of debris and irrigant using hand and rotary systems: A comparative study

    Science.gov (United States)

    Ghivari, Sheetal B; Kubasad, Girish C; Chandak, Manoj G; Akarte, NR

    2011-01-01

    Aim: To evaluate and compare the amount of debris and irrigant extruded quantitatively by using two hand and rotary nickel–titanium (Ni–Ti) instrumentation techniques. Materials and Methods: Eighty freshly extracted mandibular premolars having similar canal length and curvature were selected and mounted in a debris collection apparatus. After each instrument change, 1 ml of distilled water was used as an irrigant and the amount of irrigant extruded was measured using the Meyers and Montgomery method. After drying, the debris was weighed using an electronic microbalance to determine its weight. Statistical analysis used: The data was analyzed statistically to determine the mean difference between the groups. The mean weight of the dry debris and irrigant within the group and between the groups was calculated by the one-way ANOVA and multiple comparison (Dunnet D) test. Results: The step-back technique extruded a greater quantity of debris and irrigant in comparison to other hand and rotary Ni–Ti systems. Conclusions: All instrumentation techniques extrude debris and irrigant, it is prudent on the part of the clinician to select the instrumentation technique that extrudes the least amount of debris and irrigant, to prevent a flare-up phenomena. PMID:21814364

  3. Large Scale Numerical Modelling to Study the Dispersion of Persistent Toxic Substances Over Europe

    Science.gov (United States)

    Aulinger, A.; Petersen, G.

    2003-12-01

    For the past two decades environmental research at the GKSS Research Centre has been concerned with airborne pollutants with adverse effects on human health. The research was mainly focused on investigating the dispersion and deposition of heavy metals like lead and mercury over Europe by means of numerical modelling frameworks. Lead, in particular, served as a model substance to study the relationship between emissions and human exposition. The major source of airborne lead in Germany was fuel combustion until the 1980ies when its use as gasoline additive declined due to political decisions. Since then, the concentration of lead in ambient air and the deposition rates decreased in the same way as the consumption of leaded fuel. These observations could further be related to the decrease of lead concentrations in human blood measured during medical studies in several German cities. Based on the experience with models for heavy metal transport and deposition we have now started to turn our research focus to organic substances, e.g. PAHs. PAHs have been recognized as significant air borne carcinogens for several decades. However, it is not yet possible to precisely quantify the risk of human exposure to those compounds. Physical and chemical data, known from literature, describing the partitioning of the compounds between particle and gas phase and their degradation in the gas phase are implemented in a tropospheric chemistry module. In this way, the fate of PAHs in the atmosphere due to different particle type and size and different meteorological conditions is tested before carrying out large-scale and long-time studies. First model runs have been carried out for Benzo(a)Pyrene as one of the principal carcinogenic PAHs. Up to now, nearly nothing is known about degradation reactions of particle bound BaP. Thus, they could not be taken into account in the model so far. On the other hand, the proportion of BaP in the gas phase has to be considered at higher ambient

  4. Determination of the relationship between cognitive function and hand dexterity in patients with chronic obstructive pulmonary disease (COPD): a cross-sectional study.

    Science.gov (United States)

    Soysal Tomruk, Melda; Ozalevli, Sevgi; Dizdar, Gorkem; Narin, Selnur; Kilinc, Oguz

    2015-07-01

    Hand dexterity is important for daily living activities and can be related to cognitive functions in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate the relationship between cognitive dysfunction and hand dexterity in patients with COPD. 35 COPD patients and 36 healthy individuals were assessed. The Minnesota Hand Dexterity Test and Mini Mental State Examination (MMSE) were used for assessment of cognitive function and hand dexterity. Hand dexterity test scores and cognitive function of COPD patients' were significantly lower than the healthy group (p COPD group (p COPD; however, hand dexterity did not alter according to hypoxemia severity. Hand dexterity which is important in daily living activities should be evaluated in greater detail with further studies in COPD patients.

  5. Proceeding of 1999-workshop on MHD computations 'study on numerical methods related to plasma confinement'

    International Nuclear Information System (INIS)

    Kako, T.; Watanabe, T.

    2000-06-01

    This is the proceeding of 'study on numerical methods related to plasma confinement' held in National Institute for Fusion Science. In this workshop, theoretical and numerical analyses of possible plasma equilibria with their stability properties are presented. There are also various lectures on mathematical as well as numerical analyses related to the computational methods for fluid dynamics and plasma physics. Separate abstracts were presented for 13 of the papers in this report. The remaining 6 were considered outside the subject scope of INIS. (J.P.N.)

  6. A Numerical Study for Robust Active Portfolio Management with Worst-Case Downside Risk Measure

    Directory of Open Access Journals (Sweden)

    Aifan Ling

    2014-01-01

    Full Text Available Recently, active portfolio management problems are paid close attention by many researchers due to the explosion of fund industries. We consider a numerical study of a robust active portfolio selection model with downside risk and multiple weights constraints in this paper. We compare the numerical performance of solutions with the classical mean-variance tracking error model and the naive 1/N portfolio strategy by real market data from China market and other markets. We find from the numerical results that the tested active models are more attractive and robust than the compared models.

  7. The Use of Numerical Applications in the Study of Dental Contacts

    Directory of Open Access Journals (Sweden)

    Rodica LUCA

    2010-06-01

    Full Text Available This paper seeks to explore the numerical analysis methods used in dentistry in general and those regarding teeth contacts, in particular. Typically, such an analysis consists of the following steps: modelling the actual object, mesh generation, numerical modelling and computer programming. The best known and mostly used of all is the finite element method. The paper also presents other more refined methods, for instance: CATIA and fast Fourier transform. The study of the living tissue based on numerical analysis exceeds the limitations of in vivo experiments but computers can never replicate the body adaptation capacity.

  8. Current status of regional hydrogeological studies and numerical simulations on geological disposal

    International Nuclear Information System (INIS)

    Nakao, Shinsuke; Kikuchi, Tsuneo; Ishido, Tsuneo

    2004-01-01

    Current status of regional hydrogeological studies on geological disposal including hydrogeological modeling using numerical simulators is reviewed in this report. A regional scale and boundary conditions of numerical models are summarized mainly from the results of the RHS (regional hydrogeological study) project conducted by Japan Nuclear Cycle Development Institute (JNC) in the Tono area. We also refer to the current conceptual modes of hydrology and numerical models of unsaturated zone flow at Yucca Mountain, Nevada, which is the arid site proposed for consideration as the United States' first underground high-level radioactive waste repository. Understanding behavior of a freshwater-saltwater transition zone seems to play a key role in the hydrogeological modeling in a coastal region. Technical features of a numerical simulator as a tool for geothermal reservoir modeling is also briefly described. (author)

  9. Numerical studies of the influence of food ingestion on phytoplankton and zooplankton biomasses

    OpenAIRE

    Lidia Dzierzbicka-G³owacka

    2002-01-01

    This paper presents the numerical simulations of the influence of food ingestion by a herbivorous copepod on phytoplankton and zooplankton biomasses (PZB) in the sea. The numerical studies were carried out using the phytoplankton-zooplankton-nutrient-detritus PhyZooNuDe biological upper layer model. This takes account both of fully developed primary production and regeneration mechanisms and of daily migration of zooplankton. In this model the zooplankton is treated not as a 'biomass' but as ...

  10. What Is the Role of Manual Preference in Hand-Digit Mapping During Finger Counting? A Study in a Large Sample of Right- and Left-Handers.

    Science.gov (United States)

    Zago, Laure; Badets, Arnaud

    2016-01-01

    The goal of the present study was to test whether there is a relationship between manual preference and hand-digit mapping in 369 French adults with similar numbers of right- and left-handers. Manual laterality was evaluated with the finger tapping test to evaluate hand motor asymmetry, and the Edinburgh handedness inventory was used to assess manual preference strength (MPS) and direction. Participants were asked to spontaneously "count on their fingers from 1 to 10" without indications concerning the hand(s) to be used. The results indicated that both MPS and hand motor asymmetry affect the hand-starting preference for counting. Left-handers with a strong left-hand preference (sLH) or left-hand motor asymmetry largely started to count with their left hand (left-starter), while right-handers with a strong right-hand preference (sRH) or right-hand motor asymmetry largely started to count with their right hand (right-starter). Notably, individuals with weak MPS did not show a hand-starting preference. These findings demonstrated that manual laterality contributes to finger counting directionality. Lastly, the results showed a higher proportion of sLH left-starter individuals compared with sRH right-starters, indicating an asymmetric bias of MPS on hand-starting preference. We hypothesize that the higher proportion of sLH left-starters could be explained by the congruence between left-to-right hand-digit mapping and left-to-right mental number line representation that has been largely reported in the literature. Taken together, these results indicate that finger-counting habits integrate biological and cultural information. © The Author(s) 2015.

  11. Integrated, multidisciplinary care for hand eczema: design of a randomized controlled trial and cost-effectiveness study

    Directory of Open Access Journals (Sweden)

    Boot Cécile RL

    2009-12-01

    Full Text Available Abstract Background The individual and societal burden of hand eczema is high. Literature indicates that moderate to severe hand eczema is a disease with a poor prognosis. Many patients are hampered in their daily activities, including work. High costs are related to high medical consumption, productivity loss and sick leave. Usual care is suboptimal, due to a lack of optimal instruction and coordination of care, and communication with the general practitioner/occupational physician and people involved at the workplace. Therefore, an integrated, multidisciplinary intervention involving a dermatologist, a care manager, a specialized nurse and a clinical occupational physician was developed. This paper describes the design of a study to investigate the effectiveness and cost-effectiveness of integrated care for hand eczema by a multidisciplinary team, coordinated by a care manager, consisting of instruction on avoiding relevant contact factors, both in the occupational and in the private environment, optimal skin care and treatment, compared to usual, dermatologist-led care. Methods The study is a multicentre, randomized, controlled trial with an economic evaluation alongside. The study population consists of patients with chronic, moderate to severe hand eczema, who visit an outpatient clinic of one of the participating 5 (three university and two general hospitals. Integrated, multidisciplinary care, coordinated by a care manager, including allergo-dermatological evaluation by a dermatologist, occupational intervention by a clinical occupational physician, and counselling by a specialized nurse on optimizing topical treatment and skin care will be compared with usual care by a dermatologist. The primary outcome measure is the cumulative difference in reduction of the clinical severity score HECSI between the groups. Secondary outcome measures are the patient's global assessment, specific quality of life with regard to the hands, generic quality

  12. Numerical and experimental study on laminar round free jet of Ar discharging into stagnant air

    International Nuclear Information System (INIS)

    Fumizawa, Motoo; Hishida, Makoto; Kunugi, Tomoaki

    1990-01-01

    The objective of the present study is to investigate numerically and experimentally the behavior of the fluid flow and the mass transfer of argon gas (Ar) laminar round jet discharging into stagnant air along the gravity force. The SIMPLE method and two differential numerical schemes of PLDS and QUICK are used in the TEAM code modified by adding the binary diffusion equation. The solution domain is comprised of 80X40 grids of uniform size. As the result, the following were obtained: The half radius of Ar mass fraction obtained by QUICK was in good agreement with experimental result. The half radii of axial velocity and Ar mass fraction obtained by PLDS were larger than those by QUICK due to numerical viscosity. Numerical analyses by PLDS and QUICK schemes agreed well with experimental results on centerline Ar mass fraction. Computational times of PLDS and QUICK are about 40 min. and 120 min. respectively by FACOM VP100 computer in JAERI. (author)

  13. Numerical study of damage evolution and failure in an electromagnetic corner fill operation

    International Nuclear Information System (INIS)

    Imbert, J.M.; Winkler, S.L.; Worswick, M.J.; Oliveira, D.A.; Golovashchenko, S.

    2004-01-01

    A numerical study of an electromagnetic corner fill operation using AA5754 aluminum alloy sheet was performed. Conical parts with side angles of 40 and 45 deg. (included angles of 100 and 90 deg.) were modeled. The numerical calculations were performed with an explicit dynamic finite element structural code, using an analytical electromagnetic pressure distribution. Damage evolution was predicted using a damage subroutine based on the Gurson-Tvergaard-Needleman constitutive model. Experiments were performed to validate the numerical results. Damage measurements were made using optical microscopy to determine the actual damage produced by the forming operations. Predicted final shape, failure and damage levels are presented and compared with experimental results. The numerical models were able to accurately predict damage trends. Failure was predicted in general agreement with the experiments

  14. Measures of component importance in repairable multistate systems—a numerical study

    International Nuclear Information System (INIS)

    Natvig, Bent; Huseby, Arne B.; Reistadbakk, Mads O.

    2011-01-01

    Dynamic and stationary measures of importance of a component in a repairable multistate system are an important part of reliability. For multistate systems little has been published until now on such measures even in the nonrepairable case. According to the Barlow–Proschan type measures a component is important if there is a high probability that a change in the component state causes a change in whether or not the system state is above a given state. On the other hand, the Natvig type measures focus on how a change in the component state affects the expected system uptime and downtime relative to the given system state. In the present paper we first review these measures which can be estimated using advanced simulation methods. Extending earlier work from the binary to the multistate case, a numerical study of these measures is then given for two three component systems, a bridge system and also applied to an offshore oil and gas production system. In the multistate case the importance of a component is calculated separately for each component state. Thus it may happen that a component is very important at one state, and less important, or even irrelevant at another. Unified measures combining the importances for all component states can be obtained by adding up the importance measures for each individual state. According to these unified measures a component can be important relative to a given system state but not to another. It can be seen that if the distributions of the total component times spent in the non-complete failure states for the multistate system and the component lifetimes for the binary system are identical, the Barlow–Proschan measure to the lowest system state simply reduces to the binary version of the measure. The extended Natvig measure, however, does not have this property. This indicates that the latter measure captures more information about the system. - Highlights: ► The paper discusses measures of component importance in

  15. Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 2: Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available The separator plays a key role on the performance of passive air-breathing flat-plate MFCs (FPMFC as it isolates the anaerobic anode from the air-breathing cathode. The goal of the present work was to study the separator characteristics and its effect on the performance of passive air-breathing FPMFCs. This was performed partially through characterization of structure, properties, and performance correlations of eight separators presented in Part 1. Current work (Part 2 presents a numerical model developed based on the mixed potential theory to investigate the sensitivity of the electrode potentials and the power output to the separator characteristics. According to this numerical model, the decreased peak power results from an increase in the mass transfer coefficients of oxygen and ethanol, but mainly increasing mixed potentials at the anode by oxygen crossover. The model also indicates that the peak power is affected by the proton transport number of the separator, which affects the cathode pH. Anode pH, on the other hand, remains constant due to application of phosphate buffer solution as the electrolyte. Also according to this model, the peak power is not sensitive to the resistivity of the separator because of the overshadowing effect of the oxygen crossover.

  16. Numerical study for two phase flow in the near nozzle region of turbine combustors

    International Nuclear Information System (INIS)

    Pervez, K.; Mushtaq, S.

    1999-01-01

    In the present study flow conditions in the near nozzle region of the combustion chamber have been investigated. There exists two-phase flow in this region. The overall performance and pollutant formation in the combustion chamber have been investigated. There exists two-phase flow in this region. The overall performance and pollutant formation in the combustion zone largely depends on the spray field in the near nozzle region the studies are conducted to determined the effects of multi jets on the flow pattern in the near nozzle region The phase doppler particle analyzer (PDPA) has been used to measure the velocities and sizes of the droplets. The flow field of two-phase liquid drop-air jets is formed from three injectors arranged in t line. Furthermore the two-phase flow field has been analyzed numerically also. The numerical analysis consists of two computational models, namely (i) 3 non-evaporating two-phase jets, (II) 3 evaporating two phase jets. The Eulerian-Eulerian approach in incorporated in both the numerical models. Since the flow is turbulent, a two-equation model (k-Epsilon) is implemented in the numerical analysis. Numerical solution of the conservation equation is obtained using PHOENICS computer code. Boundary conditions are provided from the experimental measurements. Numerical domain for the two models of the analysis starts at some distance (about 10 diameters of the injector orifice) where the atomization process is complete and droplet size and velocity could be measured experimentally. (author)

  17. Experimental and numerical study of guided wave propagation in a thin metamaterial plate

    International Nuclear Information System (INIS)

    Zhu, R.; Huang, G.L.; Huang, H.H.; Sun, C.T.

    2011-01-01

    In this Letter, both in-plane and out-of-plane guided waves in a thin plate with local resonators are studied numerically and experimentally. Through the numerical simulation, a new metamaterial plate design is achieved for a low-frequency bandgap in both in-plane and out-of-plane guided waves. Experiments were conducted to validate the numerical design. In the experiment, piezoelectric transducers were used to generate and receive guided wave signals. The results show that the numerical predictions are in very good agreement with the experimental measurements. Specifically, the connection between the local resonance in the thin plate and its wave attenuation mechanism was discussed. -- Highlights: → Both in-plane and out-of-plane guided waves in a thin plate with local resonators are studied numerically and experimentally. → A new metamaterial plate design is achieved for a low-frequency bandgap in both in-plane and out-of-plane guided waves. → Experiments were conducted to validate the numerical design. → The connection between the local resonance in the thin plate and its wave attenuation mechanism was investigated.

  18. Efficacy of Moringa oleifera leaf powder as a hand-washing product: a crossover controlled study among healthy volunteers.

    Science.gov (United States)

    Torondel, Belen; Opare, David; Brandberg, Bjorn; Cobb, Emma; Cairncross, Sandy

    2014-02-14

    Moringa oleifera is a plant found in many tropical and subtropical countries. Many different uses and properties have been attributed to this plant, mainly as a nutritional supplement and as a water purifier. Its antibacterial activity against different pathogens has been described in different in vitro settings. However the potential effect of this plant leaf as a hand washing product has never been studied. The aim of this study is to test the efficacy of this product using an in vivo design with healthy volunteers. The hands of fifteen volunteers were artificially contaminated with Escherichia coli. Moringa oleifera leaf powder was tested as a hand washing product and was compared with reference non-medicated liquid soap using a cross over design following an adaptation of the European Committee for Standardization protocol (EN 1499). In a second part of tests, the efficacy of the established amount of Moringa oleifera leaf powder was compared with an inert powder using the same protocol. Application of 2 and 3 g of dried Moringa oleifera leaf powder (mean log10-reduction: 2.44 ± 0.41 and 2.58 ± 0.34, respectively) was significantly less effective than the reference soap (3.00 ± 0.27 and 2.99 ± 0.26, respectively; p Moringa oleifera (2 and 3 g) but using a wet preparation, was also significantly less effective than reference soap (p Moringa oleifera powder in dried or wet preparation (mean log10-reduction: 2.70 ± 0.27 and 2.91 ± 0.11, respectively) compared with reference soap (2.97 ± 0.28). Application of calcium sulphate inert powder was significantly less effective than the 4 g of Moringa oleifera powder (p Moringa oleifera powder in dried and wet application had the same effect as non-medicated soap when used for hand washing. Efficacious and available hand washing products could be useful in developing countries in controlling pathogenic organisms that are transmitted through contaminated hands.

  19. Numerical study of two dimensional disordered systems in an external magnetic field

    International Nuclear Information System (INIS)

    Jana, Debnarayan

    2000-01-01

    We study here 2d tight-binding disordered model in an external magnetic field. By numerically diagonalizing the Hamiltonian, we characterize the eigenstates by Generalized Inverse Participation Ratio (GIPR). The properties of the eigenstates have been studied in case of random flux model as well as with the strength of disorder. Simple theoretical arguments are given in support of the numerical observation. Finally, we have also studied the multifractality of the eigenstates. All these study may shed light on the eigenstates in the center of the band in case of Integer Quantum Hall Effect (IQHE). (author)

  20. Examining pitch and numerical magnitude processing in congenital amusia: A quasi-experimental pilot study.

    Science.gov (United States)

    Nunes-Silva, Marilia; Moura, Ricardo; Lopes-Silva, Júlia Beatriz; Haase, Vitor Geraldi

    2016-08-01

    Congenital amusia is a developmental disorder associated with deficits in pitch height discrimination or in integrating pitch sequences into melodies. This quasi-experimental pilot study investigated whether there is an association between pitch and numerical processing deficits in congenital amusia. Since pitch height discrimination is considered a form of magnitude processing, we investigated whether individuals with amusia present an impairment in numerical magnitude processing, which would reflect damage to a generalized magnitude system. Alternatively, we investigated whether the numerical processing deficit would reflect a disconnection between nonsymbolic and symbolic number representations. This study was conducted with 11 adult individuals with congenital amusia and a control comparison group of 6 typically developing individuals. Participants performed nonsymbolic and symbolic magnitude comparisons and number line tasks. Results were available from previous testing using the Montreal Battery of Evaluation of Amusia (MBEA) and a pitch change detection task (PCD). Compared to the controls, individuals with amusia exhibited no significant differences in their performance on both the number line and the nonsymbolic magnitude tasks. Nevertheless, they showed significantly worse performance on the symbolic magnitude task. Moreover, individuals with congenital amusia, who presented worse performance in the Meter subtest, also presented less precise nonsymbolic numerical representation. The relationship between meter and nonsymbolic numerical discrimination could indicate a general ratio processing deficit. The finding of preserved nonsymbolic numerical magnitude discrimination and mental number line representations, with impaired symbolic number processing, in individuals with congenital amusia indicates that (a) pitch height and numerical magnitude processing may not share common neural representations, and (b) in addition to pitch processing, individuals with

  1. Hand grips strength effect on motor function in human brain using fMRI: a pilot study

    International Nuclear Information System (INIS)

    Ismail, S S; Mohamad, M; Syazarina, S O; Nafisah, W Y

    2014-01-01

    Several methods of motor tasks for fMRI scanning have been evolving from simple to more complex tasks. Motor tasks on upper extremity were applied in order to excite the increscent of motor activation on contralesional and ipsilateral hemispheres in brain. The main objective of this study is to study the different conditions for motor tasks on upper extremity that affected the brain activation. Ten healthy right handed with normal vision (3 male and 7 female, age range=20-30 years, mean=24.6 years, SD=2.21) participated in this study. Prior to the scanning, participants were trained on hand grip tasks using rubber ball and pressure gauge tool outside the scanner. During fMRI session, a block design with 30-s task blocks and alternating 30-s rest periods was employed while participants viewed a computer screen via a back projection-mirror system and instructed to follow the instruction by gripping their hand with normal and strong grips using a rubber ball. Statistical Parametric mapping (SPM8) software was used to determine the brain activation. Both tasks activated the primary motor (M1), supplementary motor area (SMA), dorsal and ventral of premotor cortex area (PMA) in left hemisphere while in right hemisphere the area of primary motor (M1) somatosensory was activated. However, the comparison between both tasks revealed that the strong hand grip showed the higher activation at M1, PMA and SMA on left hemisphere and also the area of SMA on right hemisphere. Both conditions of motor tasks could provide insights the functional organization on human brain

  2. Hand grips strength effect on motor function in human brain using fMRI: a pilot study

    Science.gov (United States)

    Ismail, S. S.; Mohamad, M.; Syazarina, S. O.; Nafisah, W. Y.

    2014-11-01

    Several methods of motor tasks for fMRI scanning have been evolving from simple to more complex tasks. Motor tasks on upper extremity were applied in order to excite the increscent of motor activation on contralesional and ipsilateral hemispheres in brain. The main objective of this study is to study the different conditions for motor tasks on upper extremity that affected the brain activation. Ten healthy right handed with normal vision (3 male and 7 female, age range=20-30 years, mean=24.6 years, SD=2.21) participated in this study. Prior to the scanning, participants were trained on hand grip tasks using rubber ball and pressure gauge tool outside the scanner. During fMRI session, a block design with 30-s task blocks and alternating 30-s rest periods was employed while participants viewed a computer screen via a back projection-mirror system and instructed to follow the instruction by gripping their hand with normal and strong grips using a rubber ball. Statistical Parametric mapping (SPM8) software was used to determine the brain activation. Both tasks activated the primary motor (M1), supplementary motor area (SMA), dorsal and ventral of premotor cortex area (PMA) in left hemisphere while in right hemisphere the area of primary motor (M1) somatosensory was activated. However, the comparison between both tasks revealed that the strong hand grip showed the higher activation at M1, PMA and SMA on left hemisphere and also the area of SMA on right hemisphere. Both conditions of motor tasks could provide insights the functional organization on human brain.

  3. Reliability of a Malay-translated questionnaire for use in a hand-arm vibration syndrome study in Malaysia.

    Science.gov (United States)

    Su, T A; Hoe, V C W

    2008-12-01

    Validity and reliability of the information relating to hand-transmitted vibration exposure and vibration-related health outcome are very important for case finding in hand-arm vibration syndrome (HAVS) studies. In a local HAVS study among a group of construction workers in Kuala Lumpur, Malaysia, a questionnaire translated into Malay was created based on the Hand-transmitted Vibration Health Surveillance--Initial Questionnaire and Clinical Assessment, from Vibration Injury Network. This study was conducted to determine the reliability of standardised questions in the questionnaire used in the study. 15 subjects were selected randomly from the sampling frame of the HAVS study. Test-retest reliability was conducted on all items contained in parts 1-6 of the questionnaire and clinical assessment form, with an interval of 13-14 days between the first and second administration. Kappa coefficient and percentage agreement were calculated for all standardised questions. The kappa coefficient and percentage agreement for all standardised questions varied from -0.174 to 1.000 and 66.7 to 100.0 percent, respectively. The kappa coefficient for important questions related to current vibratory tool usage, tingling, numbness and hand grip weakness were 0.714, 0.432, -0.077 and -0.120, respectively, while the percentage agreement for current vibratory tool usage, finger colour change, tingling, numbness and hand grip weakness were 85.7 percent, 92.8 percent, 79.5 percent, 85.7 percent and 71.4 percent, respectively. Intra-rater reliability on the extent of vibration exposure was good, with the intra-class correlation coefficient (95 percent confidence interval) ranging from 0.786 (0.334-0.931) to 0.975 (0.923-0.992). Critical questions on vascular, neurological and musculoskeletal symptoms of HAVS were found to be reliable. The history on the extent of vibration exposure revealed good reliability when explored by the investigator alone. This questionnaire is considered reliable

  4. Disturbances in body ownership in schizophrenia: evidence from the rubber hand illusion and case study of a spontaneous out-of-body experience.

    Directory of Open Access Journals (Sweden)

    Katharine N Thakkar

    Full Text Available A weakened sense of self may contribute to psychotic experiences. Body ownership, one component of self-awareness, can be studied with the rubber hand illusion (RHI. Watching a rubber hand being stroked while one's unseen hand is stroked synchronously can lead to a sense of ownership over the rubber hand, a shift in perceived position of the real hand, and a limb-specific drop in stimulated hand temperature. We aimed to assess the RHI in schizophrenia using quantifiable measures: proprioceptive drift and stimulation-dependent changes in hand temperature.The RHI was elicited in 24 schizophrenia patients and 21 matched controls by placing their unseen hand adjacent to a visible rubber hand and brushing real and rubber hands synchronously or asynchronously. Perceived finger location was measured before and after stimulation. Hand temperature was taken before and during stimulation. Subjective strength of the illusion was assessed by a questionnaire.Across groups, the RHI was stronger during synchronous stimulation, indicated by self-report and proprioceptive drift. Patients reported a stronger RHI than controls. Self-reported strength of RHI was associated with schizotypy in controls Proprioceptive drift was larger in patients, but only following synchronous stimulation. Further, we observed stimulation-dependent changes in skin temperature. During right hand stimulation, temperature dropped in the stimulated hand and rose in the unstimulated hand. Interestingly, induction of RHI led to an out-of-body experience in one patient, linking body disownership and psychotic experiences.The RHI is quantitatively and qualitatively stronger in schizophrenia. These findings suggest that patients have a more flexible body representation and weakened sense of self, and potentially indicate abnormalities in temporo-parietal networks implicated in body ownership. Further, results suggest that these body ownership disturbances might be at the heart of a subset of

  5. Disturbances in Body Ownership in Schizophrenia: Evidence from the Rubber Hand Illusion and Case Study of a Spontaneous Out-of-Body Experience

    Science.gov (United States)

    Thakkar, Katharine N.; Nichols, Heathman S.; McIntosh, Lindsey G.; Park, Sohee

    2011-01-01

    Background A weakened sense of self may contribute to psychotic experiences. Body ownership, one component of self-awareness, can be studied with the rubber hand illusion (RHI). Watching a rubber hand being stroked while one's unseen hand is stroked synchronously can lead to a sense of ownership over the rubber hand, a shift in perceived position of the real hand, and a limb-specific drop in stimulated hand temperature. We aimed to assess the RHI in schizophrenia using quantifiable measures: proprioceptive drift and stimulation-dependent changes in hand temperature. Methods The RHI was elicited in 24 schizophrenia patients and 21 matched controls by placing their unseen hand adjacent to a visible rubber hand and brushing real and rubber hands synchronously or asynchronously. Perceived finger location was measured before and after stimulation. Hand temperature was taken before and during stimulation. Subjective strength of the illusion was assessed by a questionnaire. Results Across groups, the RHI was stronger during synchronous stimulation, indicated by self-report and proprioceptive drift. Patients reported a stronger RHI than controls. Self-reported strength of RHI was associated with schizotypy in controls Proprioceptive drift was larger in patients, but only following synchronous stimulation. Further, we observed stimulation-dependent changes in skin temperature. During right hand stimulation, temperature dropped in the stimulated hand and rose in the unstimulated hand. Interestingly, induction of RHI led to an out-of-body experience in one patient, linking body disownership and psychotic experiences. Conclusions The RHI is quantitatively and qualitatively stronger in schizophrenia. These findings suggest that patients have a more flexible body representation and weakened sense of self, and potentially indicate abnormalities in temporo-parietal networks implicated in body ownership. Further, results suggest that these body ownership disturbances might be at

  6. [Bacteriological study of oral cavity of people of Mexican origin to determine etiology agents of human infections in hand bite].

    Science.gov (United States)

    Cañedo-Guzmán, Cristhyan Baruch; Espinosa-Gutiérrez, Alejandro; Guzmán-Murillo, María Antonia

    2013-01-01

    Hand infections secondary to human bites often leave serious consequences on the functioning of the hand. Such infections are caused by different bacteria. Most bacteriological studies have been made to people of Anglo-Saxon origin or descent, and based on these findings; provide treatment to patients of different origins which may not always be as effective. Descriptive, internal stratified 17 patients were isolated samples of oral cavity and dental plaque bacterial species to identify and define the possible treatment according to the species identified. Microorganisms were isolated Gram (+) and Gram (-) belonging to the normal flora of the oral cavity and dental plaque in all the cases studied, presenting a variable number of microorganisms according to age but not by sex. The group of Gram-positive bacteria isolated showed sensitivity to: erythromycin, chloramphenicol and ciprofloxacin. In the group of Gram negative: kanamycin, amoxicillin + clavulanic acid, ciprofloxacin and norfloxacin, E. Corrodens sensitive to the group of quinolones as ciprofloxacin, norfloxacin as well as ceftriaxone and cefoperazone sulbactam. The bacterial species that are commonly found in normal flora of the oral cavity and dental plaque may be potential pathogens in a hand injury where to find the appropriate conditions for their development.

  7. Evaluation of Dentin Defect Formation during Retreatment with Hand and Rotary Instruments: A Micro-CT Study.

    Science.gov (United States)

    Yilmaz, Ayca; Helvacioglu-Yigit, Dilek; Gur, Cansu; Ersev, Handan; Kiziltas Sendur, Gullu; Avcu, Egemen; Baydemir, Canan; Abbott, Paul Vincent

    2017-01-01

    The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9  μ m resolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR) or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.

  8. Evaluation of Dentin Defect Formation during Retreatment with Hand and Rotary Instruments: A Micro-CT Study

    Directory of Open Access Journals (Sweden)

    Ayca Yilmaz

    2017-01-01

    Full Text Available The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9 μm resolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.

  9. Body Schema Illusions: A Study of the Link between the Rubber Hand and Kinesthetic Mirror Illusions through Individual Differences

    Directory of Open Access Journals (Sweden)

    Morgane Metral

    2017-01-01

    Full Text Available Background. The well-known rubber hand paradigm induces an illusion by having participants feel the touch applied to a fake hand. In parallel, the kinesthetic mirror illusion elicits illusions of movement by moving the reflection of a participant’s arm. Experimental manipulation of sensory inputs leads to emergence of these multisensory illusions. There are strong conceptual similarities between these two illusions, suggesting that they rely on the same neurophysiological mechanisms, but this relationship has never been investigated. Studies indicate that participants differ in their sensitivity to these illusions, which provides a possibility for studying the relationship between these two illusions. Method. We tested 36 healthy participants to confirm that there exist reliable individual differences in sensitivity to the two illusions and that participants sensitive to one illusion are also sensitive to the other. Results. The results revealed that illusion sensitivity was very stable across trials and that individual differences in sensitivity to the kinesthetic mirror illusion were highly related to individual differences in sensitivity to the rubber hand illusion. Conclusions. Overall, these results support the idea that these two illusions may be both linked to a transitory modification of body schema, wherein the most sensitive people have the most malleable body schema.

  10. Body Schema Illusions: A Study of the Link between the Rubber Hand and Kinesthetic Mirror Illusions through Individual Differences.

    Science.gov (United States)

    Metral, Morgane; Gonthier, Corentin; Luyat, Marion; Guerraz, Michel

    2017-01-01

    The well-known rubber hand paradigm induces an illusion by having participants feel the touch applied to a fake hand. In parallel, the kinesthetic mirror illusion elicits illusions of movement by moving the reflection of a participant's arm. Experimental manipulation of sensory inputs leads to emergence of these multisensory illusions. There are strong conceptual similarities between these two illusions, suggesting that they rely on the same neurophysiological mechanisms, but this relationship has never been investigated. Studies indicate that participants differ in their sensitivity to these illusions, which provides a possibility for studying the relationship between these two illusions. We tested 36 healthy participants to confirm that there exist reliable individual differences in sensitivity to the two illusions and that participants sensitive to one illusion are also sensitive to the other. The results revealed that illusion sensitivity was very stable across trials and that individual differences in sensitivity to the kinesthetic mirror illusion were highly related to individual differences in sensitivity to the rubber hand illusion. Overall, these results support the idea that these two illusions may be both linked to a transitory modification of body schema, wherein the most sensitive people have the most malleable body schema.

  11. SPECT/CT versus MRI in patients with nonspecific pain of the hand and wrist - a pilot study

    International Nuclear Information System (INIS)

    Huellner, Martin W.; Buerkert, Alexander; Schleich, Florian S.; Strobel, Klaus; Veit-Haibach, Patrick; Schuerch, Maja; Hug, Urs; Wartburg, Urs von

    2012-01-01

    Hand and wrist pain is a diagnostic challenge for hand surgeons and radiologists due to the complex anatomy of the involved small structures. The American College of Radiology recommends MRI as the study of choice in patients with chronic wrist pain if radiographs are negative. Lately, state-of-the-art SPECT/CT systems have been introduced and may help in the diagnosis of this selected indication. This retrospective study included 21 patients with nonspecific pain of the hand/wrist. The diagnosis of nonspecific wrist pain was made by the referring hand surgeon based on patient history, clinical examination, plain radiography and clinical guidelines. All patients received planar early-phase imaging and late-phase SPECT/CT imaging as well as MRI. Lesions were divided into major (causative) and minor (not causative) pathologies according to clinical follow-up. Furthermore, oedema-like bone marrow changes seen on MRI were compared with focally increased tracer uptake seen on SPECT/CT images. MRI yielded a quite high sensitivity (0.86), but a low specificity (0.20). In contrast, SPECT/CT yielded a high specificity (1.00) and a low sensitivity (0.71). Oedema-like bone marrow changes were detected in 15 lesions in 11 patients. In ten lesions with bone marrow oedema on MRI, foci of elevated tracer uptake were detected on SPECT/CT. Overall, MRI was more sensitive, but SPECT/CT was more specific in the evaluation of causative pathologies. In this initial comparison, SPECT/CT showed higher specificity than MRI in the evaluation of causative pathologies in patients with nonspecific wrist pain. However, MRI was more sensitive. Thus, SPECT/CT was shown to be a useful problem-solving tool in the diagnostic work-up of these patients. (orig.)

  12. Perineal injury associated with hands on/hands poised and directed/undirected pushing: A retrospective cross-sectional study of non-operative vaginal births, 2011-2016.

    Science.gov (United States)

    Lee, Nigel; Firmin, Meaghan; Gao, Yu; Kildea, Sue

    2018-07-01

    Clinicians hand position and advised pushing techniques may impact on rates of perineal injury. To assess the association of four techniques used in management of second stage with risk of moderate and severe perineal injury. Retrospective cross-sectional study. A metropolitan maternity hospital and a private maternity hospital in Brisbane, Australia. Term women with singleton, cephalic presentation experiencing a non-operative vaginal birth from January 2011 to December 2016. The research sites perinatal database recorded data on clinicians approach to instructing women during second stage and hand position at birth. Women were identified from matching the inclusion criteria (n = 26,393) then grouped based on combinations of hands-on, hand- poised, directed and undirected pushing. The associations with perineal injury were estimated using odds ratios obtained by multivariate analysis. Primary outcomes were the risk of moderate and severe perineal injury. The significance was set at 0.001. In Nulliparous women there was no difference in the risk of moderate or severe perineal injury between the different techniques. In multiparous women the use of a hands-on/directed approach was associated with a significant increase in the risk of moderate (AOR 1.18, 95% CI 1.10-1.27, p < 0.001) and severe perineal injury (AOR 1.50, 95% CI 1.20-1.88, p < 0.001) compared to hands-poised/undirected. A hands poised/undirected approach could be utilised in strategies for the prevention of moderate and severe perineal injury. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Numerical study of primordial magnetic field amplification by inflation-produced gravitational waves

    International Nuclear Information System (INIS)

    Kuroyanagi, Sachiko; Tashiro, Hiroyuki; Sugiyama, Naoshi

    2010-01-01

    We numerically study the interaction of inflation-produced magnetic fields with gravitational waves, both of which originate from quantum fluctuations during inflation. The resonance between the magnetic field perturbations and the gravitational waves has been suggested as a possible mechanism for magnetic field amplification. However, some analytical studies suggest that the effect of the inflationary gravitational waves is too small to provide significant amplification. Our numerical study shows more clearly how the interaction affects the magnetic fields and confirms the weakness of the influence of the gravitational waves. We present an investigation based on the magnetohydrodynamic approximation and take into account the differences of the Alfven speed.

  14. Prevention of hand eczema

    DEFF Research Database (Denmark)

    Fisker, Maja H; Ebbehøj, Niels E; Vejlstrup, Søren Grove

    2018-01-01

    Objective Occupational hand eczema has adverse health and socioeconomic impacts for the afflicted individuals and society. Prevention and treatment strategies are needed. This study aimed to assess the effectiveness of an educational intervention on sickness absence, quality of life and severity...... of hand eczema. Methods PREVEX (PreVention of EXema) is an individually randomized, parallel-group superiority trial investigating the pros and cons of one-time, 2-hour, group-based education in skin-protective behavior versus treatment as usual among patients with newly notified occupational hand eczema...

  15. Experimental and numerical study of the flow field around a small car

    Directory of Open Access Journals (Sweden)

    Dobrev Ivan

    2017-01-01

    Full Text Available This paper presents the aerodynamic study of a small car, which participated in Shell Ecomarathon Europe competition in the Urban Concept Hydrogen class. The goal is to understand the flow field around the vehicle. First, the flow is studied numerically using computational aerodynamics. The numerical simulation is carried out by means of CFD Fluent in order to obtain the drag force experienced by the vehicle and also the flow field. Then the flow field around the car is studied in a wind tunnel by means of particle image velocimetry (PIV. The comparison of the flow fields obtained numerically and experimentally shows good correspondence. The obtained results are very helpful for future car development and permit to improve the drag and to obtain a good stability.

  16. Effect of muscle strength and pain on hand function in patients with trapeziometacarpal osteoarthritis. A cross-sectional study.

    Science.gov (United States)

    Cantero-Téllez, Raquel; Martín-Valero, Rocío; Cuesta-Vargas, Antonio

    2015-01-01

    To assess the relationship between muscle strength (Jama), and pain (VAS) levels with hand function (DASH) in patients with trapeziometarcapal osteoarthritis. Cross-sectional study. Sample of 72 patients with osteoarthritis stage 2-3 (Eaton) and trapeziometacarpal osteoarthritis. Patients were recruited when they came to the Hand Surgery Unit. Grip strength, pinch, pain and hand function were measured, and correlation and regression coefficients between them were obtained. For function, the most significant model (R(2)=0.83) included pain and strength. But it is tip to tip pinch force which has a stronger relationship with DASH (Standardized B: -57) questionnaire. Pain also influenced strength measured with the dynamometer but it was tip to tip pinch force that was the most affected. Findings confirm that there is a significant correlation between function referred by the patient and variables that can be measured in the clinic such as grip strength and pinch. The correlation between pain intensity and function was also significant, but tip to tip pinch strength had the greatest impact on the function. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  17. Treatment with a barrier-strengthening moisturizer prevents relapse of hand-eczema. An open, randomized, prospective, parallel group study.

    Science.gov (United States)

    Lodén, Marie; Wirén, Karin; Smerud, Knut; Meland, Nils; Hønnås, Helge; Mørk, Gro; Lützow-Holm, Claus; Funk, Jörgen; Meding, Birgitta

    2010-11-01

    Hand eczema influences the quality of life. Management strategies include the use of moisturizers. In the present study the time to relapse of eczema during treatment with a barrier-strengthening moisturizer (5% urea) was compared with no treatment (no medical or non-medicated preparations) in 53 randomized patients with successfully treated hand eczema. The median time to relapse was 20 days in the moisturizer group compared with 2 days in the no treatment group (p = 0.04). Eczema relapsed in 90% of the patients within 26 weeks. No difference in severity was noted between the groups at relapse. Dermatology Life Quality Index (DLQI) increased significantly in both groups; from 4.7 to 7.1 in the moisturizer group and from 4.1 to 7.8 in the no treatment group (p < 0.01) at the time of relapse. Hence, the application of moisturizers seems to prolong the disease-free interval in patients with controlled hand eczema. Whether the data is applic-able to moisturizers without barrier-strengthening properties remains to be elucidated.

  18. Does the clinical use of ethanol-based hand sanitizer elevate blood alcohol levels? A prospective study.

    Science.gov (United States)

    Miller, Michael A; Rosin, Alex; Levsky, Marc E; Patel, Manish M; Gregory, Timothy J D; Crystal, Chad S

    2006-11-01

    Ethanol-based hand sanitizers (EBHSs) are used in most health care facilities in the United States. Infection control personnel advocate the use of generous quantities of EBHS before and after contact with patients. Although it is assumed that little systemic absorption of ethanol occurs during EBHS use, many alcohols are absorbed to varying degrees via the transdermal route. Ethanol intoxication by employees in the medical workplace is a potentially serious finding, and it is of forensic and medical-legal importance to elucidate the effects of frequent use of EBHS upon serum blood ethanol levels (BELs). To investigate the effect of frequent use of EBHS upon serum blood ethanol concentrations, we prospectively studied 5 volunteers undergoing frequent application of EBHS. Enrolled subjects applied 5 mL of the product (62% denatured ethyl alcohol manufactured by Kimberley-Clark, Roswell, GA) to both hands and rubbed until dry. This activity was repeated 50 times over 4 hours. Participants had their blood drawn before as well as after completing the study. Each participant was without alcohol exposure during the 12 hours preceding the study. Five volunteers were enrolled. All had an initial blood ethanol level of less than 5 mg/dL. All 5 participants completed the 4-hour study. There were no noted adverse reactions during the study. Blood ethanol level upon completion of the 50 applications of EBHS was less than 5 mg/dL in all 5 study participants. The results of this study demonstrate that use of ethanol-based hand sanitizers, when frequently used in accordance with labeling, do not raise serum blood ethanol levels.

  19. Pet owners' attitudes and behaviours related to smoking and second-hand smoke: a pilot study.

    Science.gov (United States)

    Milberger, S M; Davis, R M; Holm, A L

    2009-04-01

    Although research indicates that second-hand smoke (SHS) harms both human and animal health, data on the percentage of pet owners who smoke or allow smoking in their homes are not readily available. To investigate pet owners' smoking behaviour and policies on smoking in their homes, and the potential for educational interventions to motivate change in pet owners' smoking behaviour. A web-based survey was used with 3293 adult pet owners. The main outcome measures were smoking behaviour of pet owners and their cohabitants; policies on smoking in pet owners' homes; and impact of information about the dangers of pet exposure to SHS on pet owners' smoking intentions. Of respondents, 21% were current smokers and 27% of participants lived with at least one smoker. Pet owners who smoke reported that information on the dangers of pet exposure to SHS would motivate them to try to quit smoking (28.4%) and ask the people with whom they live to quit smoking (8.7%) or not to smoke indoors (14.2%). Moreover, non-smoking pet owners who live with smokers said that they would ask the people with whom they live to quit (16.4%) or not smoke indoors (24.2%) if given this information. About 40% of current smokers and 24% of non-smokers living with smokers indicated that they would be interested in receiving information on smoking, quitting, or SHS. Educational campaigns informing pet owners of the risks of SHS exposure for pets could motivate some owners to quit smoking. It could also motivate these owners and non-smoking owners who cohabit with smokers make their homes smoke-free.

  20. Experimental-numerical study of heat flow in deep low-enthalpy geothermal conditions

    NARCIS (Netherlands)

    Saeid, S.; Al-Khoury, R.; Nick, H.M.; Barends, F.

    2014-01-01

    This paper presents an intensive experimental-numerical study of heat flow in a saturated porous domain. A temperature and a flow rate range compared to that existing in a typical deep low-enthalpy hydrothermal system is studied. Two main issues are examined: the effect of fluid density and