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Sample records for current pressures impacting

  1. Cumulative human impacts on Mediterranean and Black Sea marine ecosystems: assessing current pressures and opportunities.

    Directory of Open Access Journals (Sweden)

    Fiorenza Micheli

    Full Text Available Management of marine ecosystems requires spatial information on current impacts. In several marine regions, including the Mediterranean and Black Sea, legal mandates and agreements to implement ecosystem-based management and spatial plans provide new opportunities to balance uses and protection of marine ecosystems. Analyses of the intensity and distribution of cumulative impacts of human activities directly connected to the ecological goals of these policy efforts are critically needed. Quantification and mapping of the cumulative impact of 22 drivers to 17 marine ecosystems reveals that 20% of the entire basin and 60-99% of the territorial waters of EU member states are heavily impacted, with high human impact occurring in all ecoregions and territorial waters. Less than 1% of these regions are relatively unaffected. This high impact results from multiple drivers, rather than one individual use or stressor, with climatic drivers (increasing temperature and UV, and acidification, demersal fishing, ship traffic, and, in coastal areas, pollution from land accounting for a majority of cumulative impacts. These results show that coordinated management of key areas and activities could significantly improve the condition of these marine ecosystems.

  2. Cumulative human impacts on Mediterranean and Black Sea marine ecosystems: assessing current pressures and opportunities.

    Science.gov (United States)

    Micheli, Fiorenza; Halpern, Benjamin S; Walbridge, Shaun; Ciriaco, Saul; Ferretti, Francesco; Fraschetti, Simonetta; Lewison, Rebecca; Nykjaer, Leo; Rosenberg, Andrew A

    2013-01-01

    Management of marine ecosystems requires spatial information on current impacts. In several marine regions, including the Mediterranean and Black Sea, legal mandates and agreements to implement ecosystem-based management and spatial plans provide new opportunities to balance uses and protection of marine ecosystems. Analyses of the intensity and distribution of cumulative impacts of human activities directly connected to the ecological goals of these policy efforts are critically needed. Quantification and mapping of the cumulative impact of 22 drivers to 17 marine ecosystems reveals that 20% of the entire basin and 60-99% of the territorial waters of EU member states are heavily impacted, with high human impact occurring in all ecoregions and territorial waters. Less than 1% of these regions are relatively unaffected. This high impact results from multiple drivers, rather than one individual use or stressor, with climatic drivers (increasing temperature and UV, and acidification), demersal fishing, ship traffic, and, in coastal areas, pollution from land accounting for a majority of cumulative impacts. These results show that coordinated management of key areas and activities could significantly improve the condition of these marine ecosystems.

  3. From Pressures to Impacts

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky

    2006-01-01

    Life cycle assessment (LCA) has been developed as a tool for assessment of the environmental impacts which are caused by the pressures from products or systems, viewed in a life cycle perspective, i.e. covering all stages of the life cycle of the product or system from the extraction of raw...... is defined, Inventory analysis where data for the physical flows to and from all processes in the life cycle is collected and related to the functional unit, Impact assessment, where the physical flows are translated into impacts on the environment and resource base, and Interpretation where the outcomes...... of the earlier phases are interpreted in relation to the goal of the LCA. LCA is typically used for comparisons, and in order to facilitate the comparison of the rather diverse environmental impacts which are comprised by the Life Cycle Impact Assessment (LCIA) methodology, procedures have been developed...

  4. Pressure Stimulated Currents (PSCin marble samples

    Directory of Open Access Journals (Sweden)

    F. Vallianatos

    2004-06-01

    Full Text Available The electrical behaviour of marble samples from Penteli Mountain was studied while they were subjected to uniaxial stress. The application of consecutive impulsive variations of uniaxial stress to thirty connatural samples produced Pressure Stimulated Currents (PSC. The linear relationship between the recorded PSC and the applied variation rate was investigated. The main results are the following: as far as the samples were under pressure corresponding to their elastic region, the maximum PSC value obeyed a linear law with respect to pressure variation. In the plastic region deviations were observed which were due to variations of Young s modulus. Furthermore, a special burst form of PSC recordings during failure is presented. The latter is emitted when irregular longitudinal splitting is observed during failure.

  5. Programme impact on current contraception in Bangladesh.

    Science.gov (United States)

    Latif, M A

    1994-03-01

    "This paper analyses the impact of three credit programmes--the Bangladesh Rural Advancement Committee (BRAC), the Bangladesh Rural Development Board's Rural Development-12 (BRDB RD-12), and the Grameen Bank (GB), on current rate of contraception. These programmes are targeted to alleviate poverty by providing group-based credit to the rural poor in creating self employment opportunities. With small credits, these programmes combine family planning activities in terms of consciousness raising, awareness building and motivation. Sample survey data are used to analyse the problem of impact evaluation. The analyses show that the BRAC and the GB programmes have [a] significantly positive impact on the current rate of contraception, while the BRDB RD-12 programme does not have any such impact. It is also found that education, both of female[s] and male[s] separately, and child survivorship have independently positive impact[s] on current contraception."

  6. Pressure versus current scaling in a blocked bore rail gun

    Science.gov (United States)

    Barrett, B. D.; Eubank, Eric; Nunnally, W. C.

    1993-07-01

    The paper presents experimental results from a blocked bore plasma armature rail gun. A piezoelectric transducer mounted in the bore blocking structure recorded time-resolved pressures over a range of input currents from 50 to 150 kA. The bore block is located at four positions where peak current occurs for the four respective charging voltages to power the system. Problems associated with obtaining these measurements and the solutions employed are discussed. Average distances from the block face to the armature current centroid are estimated assuming a pressure balance between the magnetic and neutral pressures. The averages of the measured pressures were found to be proportional to the input current raised to the power of 1.655.

  7. Pressure ulcers: Current understanding and newer modalities of treatment

    Science.gov (United States)

    Bhattacharya, Surajit; Mishra, R. K.

    2015-01-01

    This article reviews the mechanism, symptoms, causes, severity, diagnosis, prevention and present recommendations for surgical as well as non-surgical management of pressure ulcers. Particular focus has been placed on the current understandings and the newer modalities for the treatment of pressure ulcers. The paper also covers the role of nutrition and pressure-release devices such as cushions and mattresses as a part of the treatment algorithm for preventing and quick healing process of these wounds. Pressure ulcers develop primarily from pressure and shear; are progressive in nature and most frequently found in bedridden, chair bound or immobile people. They often develop in people who have been hospitalised for a long time generally for a different problem and increase the overall time as well as cost of hospitalisation that have detrimental effects on patient's quality of life. Loss of sensation compounds the problem manifold, and failure of reactive hyperaemia cycle of the pressure prone area remains the most important aetiopathology. Pressure ulcers are largely preventable in nature, and their management depends on their severity. The available literature about severity of pressure ulcers, their classification and medical care protocols have been described in this paper. The present treatment options include various approaches of cleaning the wound, debridement, optimised dressings, role of antibiotics and reconstructive surgery. The newer treatment options such as negative pressure wound therapy, hyperbaric oxygen therapy, cell therapy have been discussed, and the advantages and disadvantages of current and newer methods have also been described. PMID:25991879

  8. Pressure ulcers: Current understanding and newer modalities of treatment

    Directory of Open Access Journals (Sweden)

    Surajit Bhattacharya

    2015-01-01

    Full Text Available This article reviews the mechanism, symptoms, causes, severity, diagnosis, prevention and present recommendations for surgical as well as non-surgical management of pressure ulcers. Particular focus has been placed on the current understandings and the newer modalities for the treatment of pressure ulcers. The paper also covers the role of nutrition and pressure-release devices such as cushions and mattresses as a part of the treatment algorithm for preventing and quick healing process of these wounds. Pressure ulcers develop primarily from pressure and shear; are progressive in nature and most frequently found in bedridden, chair bound or immobile people. They often develop in people who have been hospitalised for a long time generally for a different problem and increase the overall time as well as cost of hospitalisation that have detrimental effects on patient′s quality of life. Loss of sensation compounds the problem manifold, and failure of reactive hyperaemia cycle of the pressure prone area remains the most important aetiopathology. Pressure ulcers are largely preventable in nature, and their management depends on their severity. The available literature about severity of pressure ulcers, their classification and medical care protocols have been described in this paper. The present treatment options include various approaches of cleaning the wound, debridement, optimised dressings, role of antibiotics and reconstructive surgery. The newer treatment options such as negative pressure wound therapy, hyperbaric oxygen therapy, cell therapy have been discussed, and the advantages and disadvantages of current and newer methods have also been described.

  9. Nondestructive examination of PHWR pressure tube using eddy current technique

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Jong; Choi, Sung Nam; Cho, Chan Hee; Yoo, Hyun Joo; Moon, Gyoon Young [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2014-06-15

    A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter x 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the D2O heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

  10. Numerical simulation of high pressure water jet impacting concrete

    Science.gov (United States)

    Liu, Jialiang; Wang, Mengjin; Zhang, Di

    2017-08-01

    High pressure water jet technology is an unconventional concrete crushing technology. In order to reveal the mechanism of high pressure water jet impacting concrete, it built a three-dimensional numerical model of high pressure water jet impacting concrete based on fluid mechanics and damage mechanics. And the numerical model was verified by theoretical analysis and experiments. Based on this model, it studied the stress characteristics in concrete under high pressure water jet impacting at different time, and quantified the damage evolution rules in concrete along the water jet radial direction. The results can provide theoretical basis and guidance for the high pressure water jet crushing concrete technology.

  11. Stakeholder Pressures, Environmental Impact and Managerial Initiatives of SMEs

    DEFF Research Database (Denmark)

    Madsen, Henning; Ulhøi, John Parm

    2015-01-01

    impact was available in Denmark. Consequently, a longitudinal research project was initiated to enlighten the situation. This study investigates environmentally related initiatives taken in response to the perception of stakeholder pressures and the perceived corporate environmental impact. The empirical...

  12. Alternating current calorimetry at very high pressure and low temperature

    CERN Document Server

    Wilhelm, H

    2002-01-01

    The specific heat of CePd sub 2 sub . sub 0 sub 2 Ge sub 1 sub . sub 9 sub 8 has been measured with an ac calorimetric technique up to 22 GPa for temperatures in the range 0.3 K <=T <=10 K. A thermocouple allowed the temperature oscillations to be read when an ac heating current was sent through the sample. The inverse of the thermovoltage V sub a sub c recorded at low temperature exhibits a pronounced anomaly as a function of pressure. It is shown that 1/V sub a sub c extrapolated to zero temperature is a measure of the Sommerfeld coefficient gamma.

  13. High pressure, high current, low inductance, high reliability sealed terminals

    Science.gov (United States)

    Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

    2010-03-23

    The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

  14. Effects of shifting time on pressure impact in hydraulic systems

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhen-cai; CHEN Guo-an

    2005-01-01

    The limitations in existing measures for absorbing pressure impact in hydraulic systems were summarized in this paper. Based on the forming principle of the oil in a hydrostatic closed pressure chamber, the underlying reasons of the pressure impact were analyzed theoretically, the intrinsic laws that the extent of the pressure impact in hydraulic oil lines are affected by some factors, such as oil elastic modulus, oil line's geometrical volume, and changing rate of oil volume versus time etc, were discussed. Experimental investigations into pressure impact in all pressure chambers because of shifting were conducted under different working conditions by employing a special experimental system. The effects of shifting time on pressure impact were studied. A new concept with universal meaning, i.e. optimal shifting time, and its characterizing parameter and the methods of shifting at optimal shifting time were also proposed. The results show that shifting time lag △t is of rationality and maneuverablility. The higher the working pressure, the shorter the shifting time.

  15. Diagnosing and alleviating the impact of performance pressure on mathematical problem solving.

    Science.gov (United States)

    DeCaro, Marci S; Rotar, Kristin E; Kendra, Matthew S; Beilock, Sian L

    2010-08-01

    High-pressure academic testing situations can lead people to perform below their actual ability levels by co-opting working memory (WM) resources needed for the task at hand (Beilock, 2008). In the current work we examine how performance pressure impacts WM and design an intervention to alleviate pressure's negative impact. Specifically, we explore the hypothesis that high-pressure situations trigger distracting thoughts and worries that rely heavily on verbal WM. Individuals performed verbally based and spatially based mathematics problems in a low-pressure or high-pressure testing situation. Results demonstrated that performance on problems that rely heavily on verbal WM resources was less accurate under high-pressure than under low-pressure tests. Performance on spatially based problems that do not rely heavily on verbal WM was not affected by pressure. Moreover, the more people reported worrying during test performance, the worse they performed on the verbally based (but not spatially based) maths problems. Asking some individuals to focus on the problem steps by talking aloud helped to keep pressure-induced worries at bay and eliminated pressure's negative impact on performance.

  16. Lateral impact on pressurized glass/epoxy pipes

    Energy Technology Data Exchange (ETDEWEB)

    Santiago, Rafael C.; Alves, Marcilio [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica], e-mail: rafael.santiago@poli.usp.br, e-mail: maralves@usp.br

    2009-07-01

    This work studies the impact of a drop mass against glass/epoxy composite pipes. The experimental tests comprises an impact hammer and the set-up is such that a drop mass falls transversally to the main length of the tube. The impact response is measured with a non-contact laser system and reveals some issues explored here in a numerical model. Inner pressure was applied to the tube in order to access its influence on failure. It has been found that the numerical model represents well the structural collapse of a pressurized pipe under a lateral impact. (author)

  17. Cathode erosion in high-current high-pressure arc

    CERN Document Server

    Nemchinsky, V A

    2003-01-01

    Cathode erosion rate was experimentally investigated for two types of arcs: one with tungsten cathode in nitrogen atmosphere and one with hafnium cathode in oxygen atmosphere. Conditions were typical for plasma arc cutting systems: gas pressure from 2 to 5 atm, arc current from 200 to 400 A, gas flow rate from 50 to 130 litre min sup - sup 1. It was found that the actual cathode evaporation rate G is much lower than G sub 0 , the evaporation rate that follows from the Hertz-Knudsen formula: G = nu G sub 0. The difference is because some of the evaporated particles return back to the cathode. For conditions of our experiments, the factor nu could be as low as 0.01. It was shown experimentally that nu depends strongly on the gas flow pattern close to the cathode. In particular, swirling the gas increases nu many times. To explain the influence of gas swirling, model calculations of gas flows were performed. These calculations revealed difference between swirling and non-swirling flows: swirling the gas enhances...

  18. Climate and current anthropogenic impacts on fisheries

    DEFF Research Database (Denmark)

    Brander, Keith

    2013-01-01

    this in and to combat other human pressures, such as pollution, has been slow to mature, but is showing positive trends. The need to protect marine ecosystems for their intrinsic value and for the services they provide has also been recognised and is being embodied in legislation and turned into operational tools...... of research that will help us to adapt and on the development of practices and management that will insure against future change...

  19. Water Waves from General, Time-Dependent Surface Pressure Distribution in the Presence of a Shear Current

    CERN Document Server

    Li, Yan

    2015-01-01

    We obtain a general solution for the water waves resulting from a general, time-dependent surface pressure distribution, in the presence of a shear current of uniform vorticity beneath the surface, in three dimensions. Linearized governing equations and boundary conditions including the effects of gravity, a distributed external pressure disturbance, and constant finite depth, are solved analytically, and particular attention is paid to classic initial value problems: an initial pressure impulse and a steady pressure distribution which appears suddenly. In the present paper, good agreement with previous results is demonstrated. We subsequently show both analytically and numerically how transient waves from a suddenly appearing steady pressure distribution vanis for large times, and steady ship waves remain. The transient contribution to wave resistance was derived. The results show that a shear current has significant impact on the transient wave motions, resulting in asymmetry between upstream and downstream...

  20. Impact of consolidation pressure on contaminant migration in clay liner

    Directory of Open Access Journals (Sweden)

    Zhi-hong ZHANG

    2013-07-01

    Full Text Available Consolidation deformation occurs in clay liners under the self-weight of wastes at a simple garbage dump or dredged sediment dump, which leads to a decrease in the porosity. However, the migration of contaminants in clay liners is influenced by the porosity. Thus, the impact of consolidation deformation of clay liners on the migration of contaminants cannot be ignored. Based on Biot’s consolidation theory, the contaminant migration theory, and consideration of the three kinds of migration mechanisms of convection, diffusion, and adsorption, a one-dimensional migration model of contaminants in deforming porous media was established, and the finite difference method was adopted to obtain the numerical solutions for an established initial-boundary value problem. The impact of consolidation pressure on the migration law of a contaminant was studied. The results show that, regardless of adsorption modes, different consolidation pressures have similar impacts on the migration law of the contaminant. Namely, over a certain migration time, the greater the consolidation pressure is, the smaller the migration depth of the contaminant. The results also show that, while the migration time increases, the impact of a certain increment of consolidation pressure on the variation of contaminant concentration with the depth increases gradually and, while the migration depth increases, the impact of a certain increment of consolidation pressure on the variation of the contaminant concentration with time increases gradually.

  1. Performance Evaluation of Pressure Transducers for Water Impacts

    Science.gov (United States)

    Vassilakos, Gregory J.; Stegall, David E.; Treadway, Sean

    2012-01-01

    The Orion Multi-Purpose Crew Vehicle is being designed for water landings. In order to benchmark the ability of engineering tools to predict water landing loads, test programs are underway for scale model and full-scale water impacts. These test programs are predicated on the reliable measurement of impact pressure histories. Tests have been performed with a variety of pressure transducers from various manufacturers. Both piezoelectric and piezoresistive devices have been tested. Effects such as thermal shock, pinching of the transducer head, and flushness of the transducer mounting have been studied. Data acquisition issues such as sampling rate and anti-aliasing filtering also have been studied. The response of pressure transducers have been compared side-by-side on an impulse test rig and on a 20-inch diameter hemisphere dropped into a pool of water. The results have identified a range of viable configurations for pressure measurement dependent on the objectives of the test program.

  2. Magnetized direct current microdischarge I. Effect of the gas pressure

    Science.gov (United States)

    Levko, Dmitry; Raja, Laxminarayan L.

    2017-03-01

    Following Paschen's law, electrical breakdown of gaps with small pd, where p is the gas pressure and d is the interelectrode gap, requires extremely high voltages. This means that the breakdown voltage for low-pressure microdischarges is of the order of a few kilovolts. This makes impractical the generation of low-pressure dc microdischarges. The application of dc magnetic field confines electrons in the cathode-anode gap. This leads to the significant decrease in the breakdown voltage because each electron experiences many collisions during its diffusion toward the anode. However, as was obtained experimentally, magnetized low-pressure microdischarges experience numerous instabilities whose nature is still not completely understood. In the present paper, we study the influence of the magnetic field on the low-pressure microdischarges. We use the self-consistent one-dimensional Particle-in-Cell Monte Carlo collisions model, which takes into account the electron magnetization while ions remain unmagnetized. We obtain striations in the discharge. We show that these striations appear in both homogeneous and non-homogeneous magnetic fields. We find simple expression for the instability growth rate, which shows that the instability results from ionization processes.

  3. Assessing cumulative pressures and impacts in a regional scale: HELCOM Baltic Sea Impact Index

    DEFF Research Database (Denmark)

    Korpinen, S.; Meski, L.; Andersen, Jesper;

    of identifying hot spots needs to be replaced by spatial high-resolution maps associated with estimated impacts on key ecosystem components. The Baltic Sea Marine Environment Protection Commission (HELCOM) took a first step towards an initial regional assessment of anthropogenic pressures in the Initial Holistic...... of macrozoobenthic communities in some Baltic sub-basins and the results have suggested that more specific selection of pressures is needed in order to assess anthropogenic impacts on benthic habitats. Such an adaptation of the tool has already been tested to assess the sea-floor integrity under the MSFD qualitative...... Assessment of the Baltic Sea by producing the Baltic Sea Pressure Index (BSPI) and the Baltic Sea Impact Index (BSII). The BSPI visualizes cumulative anthropogenic pressures in the Baltic Sea scale, whereas the BSII consists of potential impacts of anthropogenic pressures on key ecosystem components...

  4. Long-Run Impact of Increased Wage Pressure

    DEFF Research Database (Denmark)

    Hansen, Claus Thustrup

    1999-01-01

    An unanticipated permanent increase in wage pressure is analyzed in a dynamic general-equilibrium model combining standard theory of capital accumulation and monopolistic wage setting. The long-run (steady-state) implications are identical percentage reduction in employment, consumption, and capi......, and capital stock whereas wages and the real interest rate are unchanged. The reduction in employment on impact is larger than the steady-state reduction whereas wages rise and the real interest rate declines on impact...

  5. Impact of coronary tortuosity on coronary pressure: numerical simulation study.

    Directory of Open Access Journals (Sweden)

    Yang Li

    Full Text Available BACKGROUND: Coronary tortuosity (CT is a common coronary angiographic finding. Whether CT leads to an apparent reduction in coronary pressure distal to the tortuous segment of the coronary artery is still unknown. The purpose of this study is to determine the impact of CT on coronary pressure distribution by numerical simulation. METHODS: 21 idealized models were created to investigate the influence of coronary tortuosity angle (CTA and coronary tortuosity number (CTN on coronary pressure distribution. A 2D incompressible Newtonian flow was assumed and the computational simulation was performed using finite volume method. CTA of 30°, 60°, 90°, 120° and CTN of 0, 1, 2, 3, 4, 5 were discussed under both steady and pulsatile conditions, and the changes of outlet pressure and inlet velocity during the cardiac cycle were considered. RESULTS: Coronary pressure distribution was affected both by CTA and CTN. We found that the pressure drop between the start and the end of the CT segment decreased with CTA, and the length of the CT segment also declined with CTA. An increase in CTN resulted in an increase in the pressure drop. CONCLUSIONS: Compared to no-CT, CT can results in more decrease of coronary blood pressure in dependence on the severity of tortuosity and severe CT may cause myocardial ischemia.

  6. State-of-Art Empirical Modeling of Ring Current Plasma Pressure

    Science.gov (United States)

    Yue, C.; Ma, Q.; Wang, C. P.; Bortnik, J.; Thorne, R. M.

    2015-12-01

    The plasma pressure in the inner magnetosphere plays a key role in plasma dynamics by changing magnetic field configurations and generating the ring current. In this study, we present our preliminary results of empirically constructing 2D equatorial ring current pressure and pressure anisotropy spatial distributions controlled by Dst based on measurements from two particle instruments (HOPE and RBSPICE) onboard Van Allen Probes. We first obtain the equatorial plasma perpendicular and parallel pressures for different species including H+, He+, O+ and e- from 20 eV to ~1 MeV, and investigate their relative contributions to the total plasma pressure and pressure anisotropy. We then establish empirical equatorial pressure models within ~ 6 RE using a state-of-art machine learning technique, Support Vector Regression Machine (SVRM). The pressure models predict equatorial perpendicular and parallel plasma thermal pressures (for each species and for total pressures) and pressure anisotropy at any given r, MLT, Bz/Br (equivalent Z distance), and Dst within applicable ranges. We are currently validating our model predictions and investigating how the ring current pressure distributions and the associated pressure gradients vary with Dst index.

  7. Current California Drought: Impact on Citrus Trees and Potential Mitigation

    Science.gov (United States)

    California is in another cycle of extended drought. The article reviews and discusses likely impact of the current drought on citrus growers and potential mitigation techniques. Citrus physiological responses to water stress is briefly reviewed. The direct impact of drought on citrus is reduced frui...

  8. Flexible pressure sensors for smart protective clothing against impact loading

    Science.gov (United States)

    Wang, Fei; Zhu, Bo; Shu, Lin; Tao, Xiaoming

    2014-01-01

    The development of smart protective clothing will facilitate the quick detection of injuries from contact sports, traffic collisions and other accidents. To obtain real-time information like spatial and temporal pressure distributions on the clothing, flexible pressure sensor arrays are required. Based on a resistive fabric strain sensor we demonstrate all flexible, resistive pressure sensors with a large workable pressure range (0-8 MPa), a high sensitivity (1 MPa-1) and an excellent repeatability (lowest non-repeatability ±2.4% from 0.8 to 8 MPa) that can be inexpensively fabricated using fabric strain sensors and biocompatible polydimethylsiloxane (PDMS). The pressure sensitivity is tunable by using elastomers with different elasticities or by the pre-strain control of fabric strain sensors. Finite element simulation further confirms the sensor design. The simple structure, large workable pressure range, high sensitivity, high flexibility, facile fabrication and low cost of these pressure sensors make them promising candidates for smart protective clothing against impact loading.

  9. FISCAL PRESSURE IN ROMANIA IN THE CURRENT PERIOD

    Directory of Open Access Journals (Sweden)

    HARALAMBIE GEORGE ALIN

    2014-05-01

    Full Text Available Determination of optimal fiscal pressure threshold is difficult to determine given the conditions under which the state must ensure a balance between the goals to be funded, on account of the tax levies, and need to be available to the economic operators and the general public a sufficient portion of the income to continue their work. Practice has shown that an excessive taxation results in reducing budget revenue due to tax fraud and abstinence of tax payers. They will find ingenious ways to evade the payment of tax liabilities by non-taxable matter or by establishing their domicile for tax purposes in a country with low taxation.

  10. The immediate effects of lidocaine iontophoresis using interferential current on pressure sense threshold and tactile sensation.

    Science.gov (United States)

    Yoosefinejad, Amin Kordi; Motealleh, Alireza; Abbasnia, Keramatollah

    2016-01-01

    Iontophoresis is the noninvasive delivery of ions using direct current. The direct current has some disadvantages such as skin burning. Interferential current is a kind of alternating current without limitations of direct current; so the purpose of this study is to investigate and compare the effects of lidocaine, interferential current and lidocaine iontophoresis using interferential current. 30 healthy women aged 20-24 years participated in this randomized clinical trial study. Pressure, tactile and pain thresholds were evaluated before and after the application of treatment methods. Pressure, tactile and pain sensitivity increased significantly after the application of lidocaine alone (p < 0.005) and lidocaine iontophoresis using interferential current (p < 0.0001). Lidocaine iontophoresis using interferential current can increase perception threshold of pain, tactile stimulus and pressure sense more significantly than lidocaine and interferential current alone.

  11. Impact of Negative Sequence Current Injection by Wind Power Plants

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay; Göksu, Ömer; Teodorescu, Remus

    2013-01-01

    This paper presents an analysis of the impact from negative sequence current injection by wind power plants in power systems under steady-state and short-term unbalanced conditions, including faults. The separate positive and negative sequence current control capability of the grid-side converter...

  12. Pressure-based impact method to count bedload particles

    Science.gov (United States)

    Antico, Federica; Mendes, Luís; Aleixo, Rui; Ferreira, Rui M. L.

    2017-04-01

    Bedload transport processes determine morphological changes in fluvial, estuarine and coastal domains, thus impacting the diversity and quality of ecosystems and human activities such as river management, coastal protection or dam operation. In spite of the advancements made in the last 60 years, driven by the improvements in measurement techniques, research efforts on grain-scale mechanics of bedload are still required, especially to clarify the intermittent nature of bedload, its stochastic structure and its scale dependence. A new impact-based device to measure bedload transport - MiCas system - is presented in this work. It was designed to meet the following key requirements: simple data output composed of time instant and location of impacts; no need for post-processing - impacts determined through hardware and firmware; capable of computing simple statistics in real time such as cumulative particle counting and discrete lateral distribution of cumulative particle counts; able to run for very large time periods (days, weeks); ability to detect particle impacts of large size fractions that are separated by a few milliseconds; composed of robust and relatively cheap components. The system's firmware analyses pressure time series, namely recognizing the imprints of impacts of individual particles as they hit pressurized membranes. A pattern analysis algorithm is used to identify the impact events. The implementation of this principle in a dedicated microprocessor allows for the real-time measurements of particle hits and cumulative particle count. To validate the results obtained by the MiCas system, Experiments were carried out in the 12.5m long and 40.5cm wide glass-sided flume of the Laboratory of Hydraulics and Environment of Instituto Superior Técnico, Lisbon. This flume has two independent circuits for water and sediment recirculation. A cohesionless granular bed, composed of 4 layers of 5 mm glass beads, subjected to a steady-uniform turbulent open

  13. Stakeholder Pressures, Environmental Impact and Managerial Initiatives of SMEs

    DEFF Research Database (Denmark)

    Madsen, Henning; Ulhøi, John Parm

    2015-01-01

    impact was available in Denmark. Consequently, a longitudinal research project was initiated to enlighten the situation. This study investigates environmentally related initiatives taken in response to the perception of stakeholder pressures and the perceived corporate environmental impact. The empirical......Environmental sustainability has become an issue of uttermost importance for business organisations. Therefore, the implementation of corporate environmental initiatives has been vigorously embraced by industry. Two decades ago, no clear picture of industry initiatives to reduce their environmental...... popularity of self-regulation, voluntary initiatives do not tend to be widely adopted by SMEs, stressing a need for a continuing regulation of industry’s behaviour in relation to environmental issues....

  14. Current and future impact of osteoarthritis on health care

    DEFF Research Database (Denmark)

    Turkiewicz, A; Petersson, I F; Björk, J

    2014-01-01

    OBJECTIVE: To estimate the current and future (to year 2032) impact of osteoarthritis (OA) health care seeking. METHOD: Population-based study with prospectively ascertained data from the Skåne Healthcare Register (SHR), Sweden, encompassing more than 15 million person-years of primary and specia......OBJECTIVE: To estimate the current and future (to year 2032) impact of osteoarthritis (OA) health care seeking. METHOD: Population-based study with prospectively ascertained data from the Skåne Healthcare Register (SHR), Sweden, encompassing more than 15 million person-years of primary...

  15. The sensitivity of the burst performance of impact damaged pressure vessels to material strength properties

    Science.gov (United States)

    Lasn, K.; Vedvik, N. P.; Echtermeyer, A. T.

    2016-07-01

    This numerical study is carried out to improve the understanding of short-term residual strength of impacted composite pressure vessels. The relationship between the impact, created damage and residual strength is predicted by finite element (FE) analysis. The burst predictions depend largely on the strength properties used in the material models. However, it is typically not possible to measure all laminate properties on filament wound structures. Reasonable testing efforts are concentrated on critical properties, while obtaining other less sensitive parameters from e.g. literature. A parametric FE model is hereby employed to identify the critical strength properties, focusing on the cylindrical section of the pressure vessel. The model simulates an impactor strike on an empty vessel, which is subsequently pressurized until burst. Monte Carlo Simulations (MCS) are employed to investigate the correlations between strength related material parameters and the burst pressure. The simulations indicate the fracture toughness of the composite, hoop layer tensile strength and the yield stress of the PE liner as the most influential parameters for current vessel and impact configurations. In addition, the conservative variation in strength parameters is shown to have a rather moderate effect (COV ca. 7%) on residual burst pressures.

  16. Development of a Numerical Model of Hypervelocity Impact into a Pressurized Composite Overwrapped Pressure Vessel

    Science.gov (United States)

    Garcia, M. A.; Davis, B. A.; Miller, J. E.

    2017-01-01

    As the outlook for space exploration becomes more ambitious and spacecraft travel deeper into space than ever before, it is increasingly important that propulsion systems perform reliably within the space environment. The increased reliability compels designers to increase design margin at the expense of system mass, which contrasts with the need to limit vehicle mass to maximize payload. Such are the factors that motivate the integration of high specific strength composite materials in the construction of pressure vessels commonly referred to as composite overwrapped pressure vessels (COPV). The COPV consists of a metallic liner for the inner shell of the COPV that is stiff, negates fluid permeation and serves as the anchor for composite laminates or filaments, but the liner itself cannot contain the stresses from the pressurant it contains. The compo-site-fiber reinforced polymer (CFRP) is wound around the liner using a combination of hoop (circumferential) and helical orientations. Careful consideration of wrap orientation allows the composite to evenly bear structural loading and creates the COPV's characteristic high strength to weight ratio. As the CFRP overwrap carries most of the stresses induced by pressurization, damage to the overwrap can affect mission duration, mission success and potentially cause loss-of-vehicle/loss-of-crew. For this reason, it is critical to establish a fundamental understanding of the mechanisms involved in the failure of a stressed composite such as that of the COPV. One of the greatest external threats to the integrity of a spacecraft's COPV is an impact from the meteoroid and orbital debris environments (MMOD). These impacts, even from submillimeter particles, generate extremely high stress states in the CFRP that can damage numerous fibers. As a result of this possibility, initial assumptions in survivability analysis for some human-rated NASA space-craft have assumed that any alteration of the vessel due to impact is

  17. Impact of Negative Sequence Current Injection by Wind Power Plants

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay; Göksu, Ömer; Teodorescu, Remus;

    2013-01-01

    This paper presents an analysis of the impact from negative sequence current injection by wind power plants in power systems under steady-state and short-term unbalanced conditions, including faults. The separate positive and negative sequence current control capability of the grid-side converters...... of full scale converter type wind turbines may be utilized to alter voltage imbalance at the point of connection and further into the grid, in turn changing the resultant negative sequence current flow in the grid. The effects of such control actions have been analyzed and discussed through theoretical...

  18. Current components, pressure, and other data from moored current meters and pressure gauges from FIXED PLATFORMS from the Greenland and Beaufort Seas from 28 March 1987 to 01 June 1988 (NODC Accession 8900129)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current components, pressure, and other data were collected from moored current meters and pressure gauges from FIXED PLATFORMS in the Greenland and Beaufort Seas....

  19. An experimental study of impact loading on deck of shore-connecting jetties ex-posed to oblique waves and current

    Institute of Scientific and Technical Information of China (English)

    孟艳秋; 陈国平; 严士常; 童朝锋

    2014-01-01

    The impact pressure from waves is an important issue to be considered in the design of coastal structures. In this paper, the waves acting on the deck of a shore-connecting jetty on a slope exposed to oblique waves and in the presence of current are examined based on laboratory experiments. The impact pressures are measured on a 1:50 scale model of a jetty head with down-standing beams and berthing members. The relations of the impact pressure with the incident wave angle and the current velocity are examined. It is shown that the impact pressure is sensitive to the wave angle and the current velocity. A computational model for the impact load on the deck of shore-connecting jetties exposed to oblique waves and current is developed.

  20. Emission of excimer radiation from direct current, high-pressure hollow cathode discharges

    Science.gov (United States)

    El-Habachi, Ahmed; Schoenbach, Karl H.

    1998-01-01

    A novel, nonequilibrium, high-pressure, direct current discharge, the microhollow cathode discharge, has been found to be an intense source of xenon and argon excimer radiation peaking at wavelengths of 170 and 130 nm, respectively. In argon discharges with a 100 μm diam hollow cathode, the intensity of the excimer radiation increased by a factor of 5 over the pressure range from 100 to 800 mbar. In xenon discharges, the intensity at 170 nm increased by two orders of magnitude when the pressure was raised from 250 mbar to 1 bar. Sustaining voltages were 200 V for argon and 400 V for xenon discharges, at current levels on the order of mA. The resistive current-voltage characteristics of the microdischarges indicate the possibility to form arrays for direct current, flat panel excimer lamps.

  1. Impacts on oil recovery from capillary pressure and capillary heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Bognoe, Thomas

    2008-07-01

    The main conclusions drawn from this thesis are; 7 scientific papers are published on a broad variety of subjects, and describes in detail the experiments and research treated in this thesis. Scientific research has been performed, investigating the subjects of capillary pressure and capillary heterogeneities from different angles. This thesis discusses the findings in this study and aims to illustrate the benefits of the results obtained for further development of other experiments, and/or even the industrial benefits in field development. The methods for wettability alteration have developed throughout the work. From producing heterogeneous wettability alterations, the methods have improved to giving both radial and lateral uniform wettability alterations, which also remains unaltered throughout the duration of the experimental work. The alteration of wettability is dependent on initial water saturation, flow rate, aging time and crude oil composition. Capillary pressure and relative permeability curves have been measured for core plugs at different wettabilities using conventional centrifuge methods. The trends observed are mostly consistent with theory. The production mechanisms of strongly and moderately water wet chalk has been investigated. At strongly water wet conditions in fractured chalk; the flow is governed by capillary forces, showing strong impact from the fractures. At moderately water wet conditions, the impact of the fractures are absent, and a dispersed water front is observed during the displacement. The oil recovery is about the same, at the two wettabilities. Fracture crossing mechanisms at the same wettability conditions have been mapped. And the observations are consistent with those of the water floods. During strongly water wet displacement, the fracture crossing is occurring once the inlet core has reached endpoint of spontaneous imbibition. At moderately water wet conditions the fracture crossing is less abrupt, and creation of wetting

  2. Current situation of geoengineering and its impact on biodiversity

    OpenAIRE

    2013-01-01

    Interests in the process of geoengineering have grown and geoengineering is a focus for the Convention on Biological Diversity now. Geoengineering programs and experiments have been carried out tovarying extent globally and are of significance to Chinese interests. This paper originates from a review of a conference discussion and of relevant literatures. It introduces the concept of geoengineering, describes the current status of its development and discusses the potential impacts geoenginee...

  3. Field Aligned Currents Derived from Pressure Profiles Obtained from TWINS ENA Images

    Science.gov (United States)

    Wood, K.; Perez, J. D.; McComas, D. J.; Goldstein, J.; Valek, P. W.

    2015-12-01

    Field aligned currents (FACs) that flow from the Earth's magnetosphere into the ionosphere are an important coupling mechanism in the interaction of the solar wind with the Earth's magnetosphere. Assuming pressure balance along with charge conservation yields an expression for the FACs in terms of plasma pressure gradients and pressure anisotropy. The Two Wide-Angle Imaging Neutral Atom Spectrometers (TWINS) mission, the first stereoscopic ENA magnetospheric imager, provides global images of the inner magnetosphere from which ion pressure distributions and pressure anisotropies can be obtained. Following the formulations in Heineman [1990] and using results from TWINS observations, we calculate the distribution of field aligned currents for the 17-18 March 2015 geomagnetic storm in which extended ionospheric precipitation was observed. Initial results for the field aligned currents will be generated assuming an isotropic pitch angle distribution. Global maps of field aligned currents during the main and recovery phase of the storm will be presented. Heinemann, H. (1990), Representations of Currents and Magnetic Fields in Anisotropic Magnetohydrostatic Plasma, J. Geophys. Res., 95, 7789.

  4. Design of Diaphragm and Coil for Stable Performance of an Eddy Current Type Pressure Sensor.

    Science.gov (United States)

    Lee, Hyo Ryeol; Lee, Gil Seung; Kim, Hwa Young; Ahn, Jung Hwan

    2016-07-01

    The aim of this work was to develop an eddy current type pressure sensor and investigate its fundamental characteristics affected by the mechanical and electrical design parameters of sensor. The sensor has two key components, i.e., diaphragm and coil. On the condition that the outer diameter of sensor is 10 mm, two key parts should be designed so as to keep a good linearity and sensitivity. Experiments showed that aluminum is the best target material for eddy current detection. A round-grooved diaphragm is suggested in order to measure more precisely its deflection caused by applied pressures. The design parameters of a round-grooved diaphragm can be selected depending on the measuring requirements. A developed pressure sensor with diaphragm of t = 0.2 mm and w = 1.05 mm was verified to measure pressure up to 10 MPa with very good linearity and errors of less than 0.16%.

  5. The impact of exospheric neutral dynamics on ring current decay

    Science.gov (United States)

    Ilie, R.; Liemohn, M. W.; Skoug, R. M.; Funsten, H. O.; Gruntman, M.; Bailey, J. J.; Toth, G.

    2015-12-01

    The geocorona plays an important role in the energy budget of the Earth's inner magnetosphere since charge exchange of energetic ions with exospheric neutrals makes the exosphere act as an energy sink for ring current particles. Long-term ring current decay following a magnetic storm is mainly due to these electron transfer reactions, leading to the formation energetic neutral atoms (ENAs) that leave the ring current system on ballistic trajectories. The number of ENAs emitted from a given region of space depends on several factors, such as the energy and species of the energetic ion population in that region and the density of the neutral gas with which the ions undergo charge exchange. However, the density and structure of the exosphere are strongly dependent on changes in atmospheric temperature and density as well as charge exchange with the ions of plasmaspheric origin, which depletes the geocorona (by having a neutral removed from the system). Moreover, the radiation pressure exerted by solar far-ultraviolet photons pushes the geocoronal hydrogen away from the Earth in an anti-sunward direction to form a tail of neutral hydrogen. TWINS ENA images provide a direct measurement of these ENA losses and therefore insight into the dynamics of the ring current decay through interactions with the geocorona. We assess the influence of geocoronal neutrals on ring current formation and decay by analysis of the predicted ENA emissions using 6 different geocoronal models and simulations from the HEIDI ring current model during storm time. Comparison with TWINS ENA images shows that the location of the peak ENA enhancements is highly dependent on the distribution of geocoronal hydrogen density. We show that the neutral dynamics has a strong influence on the time evolution of the ring current populations as well as on the formation of energetic neutral atoms.

  6. Mouse Housing System Using Pressurized Cages Intraventilated by Direct-Current Microfans

    OpenAIRE

    Martinewski, Alexandre; Correia, Caio SC; de Souza, Nívea L; Merusse, José LB

    2012-01-01

    We performed the initial assessment of an alternative pressurized intraventilated (PIV) caging system for laboratory mice that uses direct-current microfans to achieve cage pressurization and ventilation. Twenty-nine pairs of female SPF BALB/c mice were used, with 19 experimental pairs kept in PIV cages and 10 control pairs kept in regular filter-top (FT) cages. Both groups were housed in a standard housing room with a conventional atmospheric control system. For both systems, intracage tempe...

  7. Phenomenology of plasma engine cathodes at high current rates and low pressures

    Science.gov (United States)

    Huegel, H.; Kruelle, G.

    1984-01-01

    The effects of low surrounding pressures on cathodes of arc jet engines with electromagnetic acceleration are investigated for pressure and current energies of 20 to 100 Torr. and 400 to 1000 A. Experiments with 50 mm long and 8 mm diameter tungsten-thorium cathode in a coaxial gas flow show that pre-heating of the cathode reduces the duration of the instable arc discharge and thus material loss. The use of lighter gases also reduces instability effects, as well as the use of increased pressures and a massive gas influx.

  8. Life cycle assessment part 2: current impact assessment practice.

    Science.gov (United States)

    Pennington, D W; Potting, J; Finnveden, G; Lindeijer, E; Jolliet, O; Rydberg, T; Rebitzer, G

    2004-07-01

    Providing our society with goods and services contributes to a wide range of environmental impacts. Waste generation, emissions and the consumption of resources occur at many stages in a product's life cycle-from raw material extraction, energy acquisition, production and manufacturing, use, reuse, recycling, through to ultimate disposal. These all contribute to impacts such as climate change, stratospheric ozone depletion, photooxidant formation (smog), eutrophication, acidification, toxicological stress on human health and ecosystems, the depletion of resources and noise-among others. The need exists to address these product-related contributions more holistically and in an integrated manner, providing complimentary insights to those of regulatory/process-oriented methodologies. A previous article (Part 1, Rebitzer et al., 2004) outlined how to define and model a product's life cycle in current practice, as well as the methods and tools that are available for compiling the associated waste, emissions and resource consumption data into a life cycle inventory. This article highlights how practitioners and researchers from many domains have come together to provide indicators for the different impacts attributable to products in the life cycle impact assessment (LCIA) phase of life cycle assessment (LCA).

  9. Impact of systolic blood pressure on visit-to-visit blood pressure variability in middle-aged and elderly people

    Institute of Scientific and Technical Information of China (English)

    陈朔华

    2013-01-01

    Objective To observe the impact of systolic blood pressure(SBP)on visit-to-visit blood pressure variability(BPV) in middle-aged and elderly people.Methods Visit-to-visit BPV was determined in 5440 workers in the

  10. Runout distance and dynamic pressure of pyroclastic density currents: Evidence from 18 May 1980 blast surge of Mount St. Helens

    Science.gov (United States)

    Gardner, J. E.; Andrews, B. J.

    2016-12-01

    Pyroclastic density currents (flows and surges) are one of the most deadly hazards associated with volcanic eruptions. Understanding what controls how far such currents will travel, and how their dynamic pressure evolves, could help mitigate their hazards. The distance a ground hugging, pyroclastic density current travels is partly limited by when it reverses buoyancy and lifts off into the atmosphere. The 1980 blast surge of Mount St. Helens offers an example of a current seen to lift off. Before lofting, it had traveled up to 20 km and leveled more than 600 km3 of thick forest (the blowdown zone). The outer edge of the devastated area - where burned trees that were left standing (the singe zone) - is where the surge is thought to have lifted off. We recently examined deposits in the outer parts of the blowdown and in the singe zone at 32 sites. The important finding is that the laterally moving surge travelled into the singe zone, and hence the change in tree damage does not mark the run out distance of the ground hugging surge. Eyewitness accounts and impacts on trees and vehicles reveal that the surge consisted of a fast, dilute "overcurrent" and a slower "undercurrent", where most of the mass (and heat) was retained. Reasonable estimates for flow density and velocity show that dynamic pressure of the surge (i.e., its ability to topple trees) peaked near the base of the overcurrent. We propose that when the overcurrent began to lift off, the height of peak dynamic pressure rose above the trees and stopped toppling them. The slower undercurrent continued forward, burning trees but it lacked the dynamic pressure needed to topple them. Grain-size variations argue that it slowed from 30 m/s when it entered the singe zone to 3 m/s at the far end. Buoyancy reversal and liftoff are thus not preserved in the deposits where the surge lofted upwards.

  11. Soil Quality Impacts of Current South American Agricultural Practices

    Directory of Open Access Journals (Sweden)

    Ana B. Wingeyer

    2015-02-01

    Full Text Available Increasing global demand for oil seeds and cereals during the past 50 years has caused an expansion in the cultivated areas and resulted in major soil management and crop production changes throughout Bolivia, Paraguay, Uruguay, Argentina and southern Brazil. Unprecedented adoption of no-tillage as well as improved soil fertility and plant genetics have increased yields, but the use of purchased inputs, monocropping i.e., continuous soybean (Glycine max (L. Merr., and marginal land cultivation have also increased. These changes have significantly altered the global food and feed supply role of these countries, but they have also resulted in various levels of soil degradation through wind and water erosion, soil compaction, soil organic matter (SOM depletion, and nutrient losses. Sustainability is dependent upon local interactions between soil, climate, landscape characteristics, and production systems. This review examines the region’s current soil and crop conditions and summarizes several research studies designed to reduce or prevent soil degradation. Although the region has both environmental and soil resources that can sustain current agricultural production levels, increasing population, greater urbanization, and more available income will continue to increase the pressure on South American croplands. A better understanding of regional soil differences and quantifying potential consequences of current production practices on various soil resources is needed to ensure that scientific, educational, and regulatory programs result in land management recommendations that support intensification of agriculture without additional soil degradation or other unintended environmental consequences.

  12. Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

    Science.gov (United States)

    Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thruster's anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization and acceleration zones upstream shifting as a function of increased background pressure.

  13. Current-pressure dependencies of dc magnetron discharge in inert gases

    Science.gov (United States)

    Serov, A. O.; Mankelevich, Yu A.; Pal, A. F.; Ryabinkin, A. N.

    2016-11-01

    The current-pressure (I-P) characteristics of dc magnetron discharge in inert gases (Ar, Kr and Xe) for various constant discharge voltages were measured. Under certain conditions on I-P characteristic, the nonmonotonic region of local maximum followed by a minimum is observed. It is found that increasing mass of the working gas ions results in a shift of the local maximum to lower pressures. The spatial distribution of ions in the plasma was studied by optical emission spectroscopy. Transformation of the discharge spatial structure with pressure was observed. A qualitative model of the observed trends is presented. It takes into account the pressure dependence of the discharge spatial structure, the capturing of secondary electrons by the cathode and charge exchange effects.

  14. Current-vortex filament model of nonlinear Alfven perturbations in a finite-pressure plasma

    NARCIS (Netherlands)

    Lakhin, V. P.; Schep, T. J.; Westerhof, E.

    1998-01-01

    A low-beta, two-fluid model is shown to possess solutions in the form of current-vortex filaments. The model can be viewed as that of reduced magnetohydrodynamics, extended with electron inertia, the Hall term and parallel electron pressure. These drift-Alfven filaments are the plasma analogs of poi

  15. Effect of chamber pressure on spreading and splashing of liquid drops upon impact on a dry smooth stationary surface

    Science.gov (United States)

    Mishra, Neeraj Kumar; Zhang, Yan; Ratner, Albert

    2011-08-01

    Liquid drop impacts on a smooth surface were studied at elevated chamber pressures to characterize the effect of gas pressure on drop spreading and splashing. Five common liquids were tested at impact speeds between 1.0 and 3.5 m/s and pressure up to 12 bars. Based on experiments at atmospheric pressure, a modification to the "free spreading" model (Scheller and Bousfield in AIChE Paper 41(6):1357-1367, 1995) has been proposed that improves the prediction accuracy of maximum spread factors from an error of 15-5%. At high chamber pressures, drop spreading and maximum spread factor were found to be independent of pressure. The splash ratio (Xu et al. in Phys Rev Lett 94:184505, 2005) showed a non-constant behavior, and a power-law model was demonstrated to predict the increase in splash ratio with decreasing impact speed in the low impact speed regime. Also, drop shape was found to affect splash promotion or suppression for an asymmetry greater than 7-8% of the equivalent drop diameter. The observations of the current work could be especially useful for the study of formation of deposits and wall combustion in engine cylinders.

  16. Eddy current monitoring of fatigue crack growth in Zr-2.5% Nb pressure tube

    Science.gov (United States)

    Krause, T. W.; Martin, A. E.; Sheppard, R. R.; Schankula, J. J.

    2000-05-01

    Zr-2.5% wt. Nb pressure tubes (PTs) form the core of the heat transport system in CANDU nuclear reactors. These 6 m long, 100 mm diameter tubes are operated at elevated temperatures (nominally 300 °C) and at pressures that produce hoop stresses that are 25% of the ultimate tensile strength of the PT (120 Mpa). Therefore, detection and characterization of flaws in these components becomes crucial for their continued pressure retaining integrity. If a flaw is detected, however, the cost of PT replacement is expensive. Periodic in-service inspection of a flaw that demonstrates no change in flaw characteristics can be used to allow a pressure tube to remain in-service. This requires confidence in the accuracy and reliability of methods used to inter flaw characteristics. Such confidence can only be developed by comparing nondestructive predictions with results from destructive examinations. In this work, eddy current testing was used to monitor the progressive stages of a fatigue crack, grown through pressure cycling from a notch on the inner surface of a PT. Results from a differential lift-off compensated eddy current probe were used to produce sizing estimates of the crack grown between 35% (base of notch) and 74% of the PT wall. A comparison with a destructive examination of the crack demonstrated sensitivity too changes in crack depth accurate to 5% of the tube wall thickness. Such results, combined with similar information obtained from ultrasonics will increase confidence in interpretation of PT inspection data.

  17. Electric Current Filamentation at a Non-potential Magnetic Null-point Due to Pressure Perturbation

    Science.gov (United States)

    Jelínek, P.; Karlický, M.; Murawski, K.

    2015-10-01

    An increase of electric current densities due to filamentation is an important process in any flare. We show that the pressure perturbation, followed by an entropy wave, triggers such a filamentation in the non-potential magnetic null-point. In the two-dimensional (2D), non-potential magnetic null-point, we generate the entropy wave by a negative or positive pressure pulse that is launched initially. Then, we study its evolution under the influence of the gravity field. We solve the full set of 2D time dependent, ideal magnetohydrodynamic equations numerically, making use of the FLASH code. The negative pulse leads to an entropy wave with a plasma density greater than in the ambient atmosphere and thus this wave falls down in the solar atmosphere, attracted by the gravity force. In the case of the positive pressure pulse, the plasma becomes evacuated and the entropy wave propagates upward. However, in both cases, owing to the Rayleigh-Taylor instability, the electric current in a non-potential magnetic null-point is rapidly filamented and at some locations the electric current density is strongly enhanced in comparison to its initial value. Using numerical simulations, we find that entropy waves initiated either by positive or negative pulses result in an increase of electric current densities close to the magnetic null-point and thus the energy accumulated here can be released as nanoflares or even flares.

  18. ELECTRIC CURRENT FILAMENTATION AT A NON-POTENTIAL MAGNETIC NULL-POINT DUE TO PRESSURE PERTURBATION

    Energy Technology Data Exchange (ETDEWEB)

    Jelínek, P. [University of South Bohemia, Faculty of Science, Institute of Physics and Biophysics, Branišovská 10, CZ-37005 České Budějovice (Czech Republic); Karlický, M. [Academy of Sciences of the Czech Republic, v. v. i., Astronomical Institute, Fričova 258, CZ-25165 Ondřejov (Czech Republic); Murawski, K., E-mail: pjelinek@prf.jcu.cz [Maria Curie-Skłodowska University, Institute of Physics, Group of Astrophysics, Radziszewskiego 10, PL-20031 Lublin (Poland)

    2015-10-20

    An increase of electric current densities due to filamentation is an important process in any flare. We show that the pressure perturbation, followed by an entropy wave, triggers such a filamentation in the non-potential magnetic null-point. In the two-dimensional (2D), non-potential magnetic null-point, we generate the entropy wave by a negative or positive pressure pulse that is launched initially. Then, we study its evolution under the influence of the gravity field. We solve the full set of 2D time dependent, ideal magnetohydrodynamic equations numerically, making use of the FLASH code. The negative pulse leads to an entropy wave with a plasma density greater than in the ambient atmosphere and thus this wave falls down in the solar atmosphere, attracted by the gravity force. In the case of the positive pressure pulse, the plasma becomes evacuated and the entropy wave propagates upward. However, in both cases, owing to the Rayleigh–Taylor instability, the electric current in a non-potential magnetic null-point is rapidly filamented and at some locations the electric current density is strongly enhanced in comparison to its initial value. Using numerical simulations, we find that entropy waves initiated either by positive or negative pulses result in an increase of electric current densities close to the magnetic null-point and thus the energy accumulated here can be released as nanoflares or even flares.

  19. Current situation of geoengineering and its impact on biodiversity

    Directory of Open Access Journals (Sweden)

    Senlu Yin

    2013-05-01

    Full Text Available Interests in the process of geoengineering have grown and geoengineering is a focus for the Convention on Biological Diversity now. Geoengineering programs and experiments have been carried out tovarying extent globally and are of significance to Chinese interests. This paper originates from a review of a conference discussion and of relevant literatures. It introduces the concept of geoengineering, describes the current status of its development and discusses the potential impacts geoengineering may have on biodiversity. Arguments about geoengineering in the Convention on Biological Diversity are also discussed. Researches show that geoengineering programs mainly affect biodiversity by changing the local or regional climate and environment. Large scale geoengineering programs may be prohibited in future due to uncertainty over their potential impacts on biodiversity. However, the necessity for energy saving and obligationsto reduce emissions will drive the progress of geoenginering. The future development of geoengineering is also examined. It is concluded that the techniques involved need to be of a high standard, highly efficient, low in cost and environmentally safe. Precautionary measures should be taken in the implementation of geoenginering related activities, and mechanisms for monitoring their effects should be thoroughly explored.

  20. Two-wave photon Doppler velocimetry measurements in direct impact Hopkinson pressure bar experiments

    Science.gov (United States)

    Lea, Lewis J.; Jardine, Andrew P.

    2015-09-01

    Direct impact Hopkinson pressure bar systems offer many potential advantages over split Hopkinson pressure bars, including access to higher strain rates, higher strains for equivalent striker velocity and system length, lower dispersion and faster achievement of force equilibrium. Currently advantages are gained at a significant cost: the fact that input bar data is unavailable removes all information about the striker impacted specimen face, preventing the determination of force equilibrium, and requiring approximations to be made on the sample deformation history. Recently photon Doppler velocimetry methods have been developed, which can replace strain gauges on Hopkinson bars. In this paper we discuss an experimental method and complementary data analysis for using Doppler velocimetry to measure surface velocities of the striker and output bars in a direct impact bar experiment, allowing similar data to be recorded as in a split bar system, with the same level of convenience. We discuss extracting velocity and force measurements, and improving the accuracy and convenience of Doppler velocimetry on Hopkinson bars. Results obtained using the technique are compared to equivalent split bar tests, showing improved stress measurements for the lowest and highest strains.

  1. Application of photon Doppler velocimetry to direct impact Hopkinson pressure bars.

    Science.gov (United States)

    Lea, Lewis J; Jardine, Andrew P

    2016-02-01

    Direct impact Hopkinson pressure bar systems offer many potential advantages over split Hopkinson pressure bars, including access to higher strain rates, higher strains for equivalent striker velocity and system length, lower dispersion, and faster achievement of force equilibrium. Currently, these advantages are gained at the expense of all information about the striker impacted specimen face, preventing the experimental determination of force equilibrium, and requiring approximations to be made on the sample deformation history. In this paper, we discuss an experimental method and complementary data analysis for using photon Doppler velocimetry to measure surface velocities of the striker and output bars in a direct impact bar experiment, allowing similar data to be recorded as in a split bar system. We discuss extracting velocity and force measurements, and the precision of measurements. Results obtained using the technique are compared to equivalent split bar tests, showing improved stress measurements for the lowest and highest strains in fully dense metals, and improvement for all strains in slow and non-equilibrating materials.

  2. Two-wave photon Doppler velocimetry measurements in direct impact Hopkinson pressure bar experiments

    Directory of Open Access Journals (Sweden)

    Lea Lewis J.

    2015-01-01

    Full Text Available Direct impact Hopkinson pressure bar systems offer many potential advantages over split Hopkinson pressure bars, including access to higher strain rates, higher strains for equivalent striker velocity and system length, lower dispersion and faster achievement of force equilibrium. Currently advantages are gained at a significant cost: the fact that input bar data is unavailable removes all information about the striker impacted specimen face, preventing the determination of force equilibrium, and requiring approximations to be made on the sample deformation history. Recently photon Doppler velocimetry methods have been developed, which can replace strain gauges on Hopkinson bars. In this paper we discuss an experimental method and complementary data analysis for using Doppler velocimetry to measure surface velocities of the striker and output bars in a direct impact bar experiment, allowing similar data to be recorded as in a split bar system, with the same level of convenience. We discuss extracting velocity and force measurements, and improving the accuracy and convenience of Doppler velocimetry on Hopkinson bars. Results obtained using the technique are compared to equivalent split bar tests, showing improved stress measurements for the lowest and highest strains.

  3. On the physical processes ruling an atmospheric pressure air glow discharge operating in an intermediate current regime

    Energy Technology Data Exchange (ETDEWEB)

    Prevosto, L., E-mail: prevosto@waycom.com.ar; Mancinelli, B.; Chamorro, J. C.; Cejas, E. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina); Instituto de Física del Plasma (CONICET), Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428, Buenos Aires (Argentina)

    2015-02-15

    Low-frequency (100 Hz), intermediate-current (50 to 200 mA) glow discharges were experimentally investigated in atmospheric pressure air between blunt copper electrodes. Voltage–current characteristics and images of the discharge for different inter-electrode distances are reported. A cathode-fall voltage close to 360 V and a current density at the cathode surface of about 11 A/cm{sup 2}, both independent of the discharge current, were found. The visible emissive structure of the discharge resembles to that of a typical low-pressure glow, thus suggesting a glow-like electric field distribution in the discharge. A kinetic model for the discharge ionization processes is also presented with the aim of identifying the main physical processes ruling the discharge behavior. The numerical results indicate the presence of a non-equilibrium plasma with rather high gas temperature (above 4000 K) leading to the production of components such as NO, O, and N which are usually absent in low-current glows. Hence, the ionization by electron-impact is replaced by associative ionization, which is independent of the reduced electric field. This leads to a negative current-voltage characteristic curve, in spite of the glow-like features of the discharge. On the other hand, several estimations show that the discharge seems to be stabilized by heat conduction; being thermally stable due to its reduced size. All the quoted results indicate that although this discharge regime might be considered to be close to an arc, it is still a glow discharge as demonstrated by its overall properties, supported also by the presence of thermal non-equilibrium.

  4. Influence of gas pressure on electron beam emission current of pulsed cathodic-arc-based forevacuum plasma electron source

    Science.gov (United States)

    Burdovitsin, Victor A.; Kazakov, Andrey V.; Medovnik, Alexander V.; Oks, Efim M.

    2017-09-01

    We describe our experimental investigation of the effect of background gas pressure on the emission parameters of a pulsed cathodic-arc-based forevacuum-pressure plasma-cathode electron source. We find that increased gas pressure over the range 4-16 Pa significantly reduces the beam current rise-time and significantly increases the emission current amplitude. For example, at a discharge current of 20 A, increasing the working gas pressure from 4 Pa to 16 Pa increases the emission current from 8 A to 18 A and shortens the beam rise-time from 50 μs to 20 μs. This influence of gas pressure on the electron beam parameters can be explained by the effect of arc discharge current switching from the anode to emission. In our case, the current switching effect is caused by increased working gas pressure. In the forevacuum pressure range, the increase of the electron emission current with the growth of gas pressure is due to a rise in the emission plasma potential which is caused by ion back-streaming from the plasma formed in the electron beam transport region. A model describing the influence of gas pressure on the electron emission from the plasma is presented.

  5. Evolution of the current system during solar wind pressure pulses based on aurora and magnetometer observations

    Science.gov (United States)

    Nishimura, Yukitoshi; Kikuchi, Takashi; Ebihara, Yusuke; Yoshikawa, Akimasa; Imajo, Shun; Li, Wen; Utada, Hisashi

    2016-08-01

    We investigated evolution of ionospheric currents during sudden commencements using a ground magnetometer network in conjunction with an all-sky imager, which has the advantage of locating field-aligned currents much more accurately than ground magnetometers. Preliminary (PI) and main (MI) impulse currents showed two-cell patterns propagating antisunward, particularly during a southward interplanetary magnetic field (IMF). Although this overall pattern is consistent with the Araki (solar wind sources of magnetospheric ultra-low-frequency waves. Geophysical monograph series, vol 81. AGU, Washington, DC, pp 183-200, 1994. doi: 10.1029/GM081p0183) model, we found several interesting features. The PI and MI currents in some events were highly asymmetric with respect to the noon-midnight meridian; the post-noon sector did not show any notable PI signal, but only had an MI starting earlier than the pre-noon MI. Not only equivalent currents but also aurora and equatorial magnetometer data supported the much weaker PI response. We suggest that interplanetary shocks impacting away from the subsolar point caused the asymmetric current pattern. Additionally, even when PI currents form in both pre- and post-noon sectors, they can initiate and disappear at different timings. The PI currents did not immediately disappear but coexisted with the MI currents for the first few minutes of the MI. During a southward IMF, the MI currents formed equatorward of a preexisting DP-2, indicating that the MI currents are a separate structure from a preexisting DP-2. In contrast, the MI currents under a northward IMF were essentially an intensification of a preexisting DP-2. The magnetometer and imager combination has been shown to be a powerful means for tracing evolution of ionospheric currents, and we showed various types of ionospheric responses under different upstream conditions.

  6. CO2 dissolution and its impact on reservoir pressure behavior

    NARCIS (Netherlands)

    Peters, E.; Egberts, P.J.P.; Loeve, D.; Hofstee, C.

    2015-01-01

    Geological storage of CO2 in large, saline aquifers needs to be monitored for safety purposes. In particular the observation of the pressure behavior of a storage site is relevant for the indication of CO2 leakage. However, interpretation of observed pressure is not straightforward in these systems,

  7. CO2 dissolution and its impact on reservoir pressure behavior

    NARCIS (Netherlands)

    Peters, E.; Egberts, P.J.P.; Loeve, D.; Hofstee, C.

    2015-01-01

    Geological storage of CO2 in large, saline aquifers needs to be monitored for safety purposes. In particular the observation of the pressure behavior of a storage site is relevant for the indication of CO2 leakage. However, interpretation of observed pressure is not straightforward in these systems,

  8. Impact of acoustic pressure on ambient pressure estimation using ultrasound contrast agent

    DEFF Research Database (Denmark)

    Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt

    2010-01-01

    Local blood pressure measurements provide important information on the state of health of organs in the body and can be used to diagnose diseases in the heart, lungs, and kidneys. This paper presents an approach for investigating the ambient pressure sensitivity of a contrast agent using diagnostic.......94. The second measurement series at 485 kPa showed a sensitivity of 0.41 dB/kPa with a correlation coefficient of 0.89. Based on the measurements at 500 kPa, this acoustic driving pressure was concluded to be too high causing the bubbles to be destroyed. The pressure sensitivity for these two measurement series...... ultrasound. The experimental setup resembles a realistic clinical setup utilizing a single array transducer for transmit and receive. The ambient pressure sensitivity of SonoVue (Bracco, Milano, Italy) was measured twice using two different acoustic driving pressures, which were selected based...

  9. Current and future impact of osteoarthritis on health care

    DEFF Research Database (Denmark)

    Turkiewicz, A; Petersson, I F; Björk, J

    2014-01-01

    .6% (95% confidence interval (CI): 26.5-26.8) (men 22.4%, women 30.5%). The most common locations were knee (13.8%), hip (5.8%) and hand (3.1%). Of the prevalent cases 26.8% had OA in multiple joints. By the year 2032, the proportion of the population aged ≥45 with doctor-diagnosed OA is estimated......OBJECTIVE: To estimate the current and future (to year 2032) impact of osteoarthritis (OA) health care seeking. METHOD: Population-based study with prospectively ascertained data from the Skåne Healthcare Register (SHR), Sweden, encompassing more than 15 million person-years of primary...... and specialist outpatient care and hospitalizations. We studied all Skåne region residents aged ≥45 by the end of 2012 (n = 531, 254) and determined the prevalence of doctor-diagnosed OA defined as the proportion of the prevalent population that had received a diagnosis of OA of the knee, hip, hand, or other...

  10. Mouse housing system using pressurized cages intraventilated by direct-current microfans.

    Science.gov (United States)

    Martinewski, Alexandre; Correia, Caio S C; de Souza, Nívea L; Merusse, José L B

    2012-03-01

    We performed the initial assessment of an alternative pressurized intraventilated (PIV) caging system for laboratory mice that uses direct-current microfans to achieve cage pressurization and ventilation. Twenty-nine pairs of female SPF BALB/c mice were used, with 19 experimental pairs kept in PIV cages and 10 control pairs kept in regular filter-top (FT) cages. Both groups were housed in a standard housing room with a conventional atmospheric control system. For both systems, intracage temperatures were in equilibrium with ambient room temperature. PIV cages showed a significant difference in pressure between days 1 and 8. Air speed (and consequently airflow rate) and the number of air changes hourly in the PIV cages showed decreasing trends. In both systems, ammonia concentrations increased with time, with significant differences between groups starting on day 1. Overall, the data revealed that intracage pressurization and ventilation by using microfans is a simple, reliable system, with low cost, maintenance requirements, and incidence of failures. Further experiments are needed to determine the potential influence of this system on the reproductive performance and pulmonary integrity in mice.

  11. Influence of ambient air pressure on impact pressure caused by breaking waves

    NARCIS (Netherlands)

    Moutzouris, C.

    1979-01-01

    Engineers are interested in the dynamics of the interface waterstructure. In case of breaking of water waves on a structure high positive and sometimes negative pressures of very short duration occur. Not only the maxima and minima of the pressures on the structure are important to a designing

  12. Influence of ambient air pressure on impact pressure caused by breaking waves

    NARCIS (Netherlands)

    Moutzouris, C.

    1979-01-01

    Engineers are interested in the dynamics of the interface waterstructure. In case of breaking of water waves on a structure high positive and sometimes negative pressures of very short duration occur. Not only the maxima and minima of the pressures on the structure are important to a designing engin

  13. Comprehensive management of pressure ulcers in spinal cord injury: Current concepts and future trends

    Science.gov (United States)

    Kruger, Erwin A.; Pires, Marilyn; Ngann, Yvette; Sterling, Michelle; Rubayi, Salah

    2013-01-01

    Pressure ulcers in spinal cord injury represent a challenging problem for patients, their caregivers, and their physicians. They often lead to recurrent hospitalizations, multiple surgeries, and potentially devastating complications. They present a significant cost to the healthcare system, they require a multidisciplinary team approach to manage well, and outcomes directly depend on patients' education, prevention, and compliance with conservative and surgical protocols. With so many factors involved in the successful treatment of pressure ulcers, an update on their comprehensive management in spinal cord injury is warranted. Current concepts of local wound care, surgical options, as well as future trends from the latest wound healing research are reviewed to aid medical professionals in treating patients with this difficult problem. PMID:24090179

  14. Direct measurements of the pressure distribution along the contact area during droplet impact

    Science.gov (United States)

    Nguyen, Thanh-Vinh; Matsumoto, Kiyoshi; Shimoyama, Isao

    2016-11-01

    We report direct measurements of the pressure distribution on the contact area during the impact of a droplet on a micropillar array. The measurements were realized using an array of MEMS-based force sensors fabricated underneath the micropillars. We show that immediately after the droplet hits the surface, the pressure becomes maximum at the center of the contact area and this maximum pressure value is more than 10 times larger than the dynamic pressure. This result emphasizes the effect of water-hammer-type pressure during the early stage of the impact. Furthermore, our measurement results demonstrate that the critical pressure associated with Cassie-Wenzel transition agrees well with the maximum capillary pressure of the micropillar array.

  15. Impact of air pressure on volatile organic compound emissions from a carpet

    Institute of Scientific and Technical Information of China (English)

    高鹏; 邓琴琴; LIN; Chao-hsin; 杨旭东

    2009-01-01

    The measurement of volatile organic compound (VOC) emissions from materials is normally conducted under standard environmental conditions, i.e., (23±1) ℃ temperature, (50±5)% relative humidity, and 0.1 MPa pressure. In order to define VOC emissions in non-standard environmental conditions, it is necessary to study the impact of key environmental parameters on emissions. This paper evaluates the impact of air pressure on VOC emissions from an aircraft carpet. The correlation between air pressure and VOC diffusion coefficient is derived, and the emission model is applied to studying the VOC emissions under pressure conditions of less than 0.1 MPa.

  16. Correlation of pressure stimulated currents in rocks with the damage parameter

    Directory of Open Access Journals (Sweden)

    F. Vallianatos

    2007-06-01

    Full Text Available Pressure Stimulated Current (PSC experiments were conducted on marble samples to correlate PSC with the damage parameter, D. The phenomena and procedures taking place in the vicinity of the fracture limit were observed and analytically described. PSC recordings were conducted by application of uniaxial compressional stress, both at a constant stress rate and at a constant deformation rate. A linear relationship was shown to exist between the emitted PSC and the damage parameter which quantifies the deviation from linear elasticity and the concentration of microcracks.

  17. Numerical simulation and experimental validation of a direct current air corona discharge under atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    Liu Xing-Hua; He Wei; Yang Fan; Wang Hong-Yu; Liao Rui-Jin; Xiao Han-Guang

    2012-01-01

    Air corona discharge is one of the critical problems associated with high-voltage equipment.Investigating the corona mechanism plays a key role in enhancing the electrical insulation performance.An improved self-consistent multi-component two-dimensional plasma hybrid model is presented for the simulation of a direct current atmospheric pressure corona discharge in air.The model is based on plasma hydrodynamic and chemical models,and includes 12 species and 26 reactions.In addition,the photoionization effect is introduced into the model.The simulation on a bar-plate electrode configuration with an inter-electrode gap of 5.0 mm is carried out.The discharge voltage-current characteristics and the current density distribution predicted by the hybrid model agree with the experimental measurements.In addition,the dynamics of volume charged species generation,discharge current waveform,current density distribution at an electrode,charge density,electron temperature,and electric field variations are investigated in detail based on the model.The results indicate that the model can contribute valuable insights into the physics of an air plasma discharge.

  18. Surface Pressure Dependencies in the GEOS-Chem-Adjoint System and the Impact of the GEOS-5 Surface Pressure on CO2 Model Forecast

    Science.gov (United States)

    Lee, Meemong; Weidner, Richard

    2016-01-01

    In the GEOS-Chem Adjoint (GCA) system, the total (wet) surface pressure of the GEOS meteorology is employed as dry surface pressure, ignoring the presence of water vapor. The Jet Propulsion Laboratory (JPL) Carbon Monitoring System (CMS) research team has been evaluating the impact of the above discrepancy on the CO2 model forecast and the CO2 flux inversion. The JPL CMS research utilizes a multi-mission assimilation framework developed by the Multi-Mission Observation Operator (M2O2) research team at JPL extending the GCA system. The GCA-M2O2 framework facilitates mission-generic 3D and 4D-variational assimilations streamlining the interfaces to the satellite data products and prior emission inventories. The GCA-M2O2 framework currently integrates the GCA system version 35h and provides a dry surface pressure setup to allow the CO2 model forecast to be performed with the GEOS-5 surface pressure directly or after converting it to dry surface pressure.

  19. Pressure stimulated currents in rocks and their correlation with mechanical properties

    Directory of Open Access Journals (Sweden)

    I. Stavrakas

    2004-01-01

    Full Text Available The spontaneous electrification of marble samples was studied while they were subjected to uniaxial stress. The Pressure Stimulated Current (PSC technique was applied to measure the charge released from compressed Dionysos marble samples, while they were subjected to cyclic loading. The experimental results demonstrate that, in the linear elastic region of the sample, no PSC is recorded, while beyond the stress limit (s>0.60, observable variations appear, which increase considerably in the vicinity of sample failure, reaching a maximum value just before the failure. The emitted current is reduced on each loading cycle and it has a reciprocal dependence to the normalized Young modulus. The MCD model, applied out of the vicinity of sample failure explains successfully the above findings. The existence of a 'memory-like' behavior of the sample, could justify the weakness or absence of electrical earthquake precursors, during an aftershock sequence.

  20. Vulnerability analysis of a pressurized aluminum composite vessel against hypervelocity impacts

    Directory of Open Access Journals (Sweden)

    Hereil Pierre-Louis

    2015-01-01

    Full Text Available Vulnerability of high pressure vessels subjected to high velocity impact of space debris is analyzed with the response of pressurized vessels to hypervelocity impact of aluminum sphere. Investigated tanks are CFRP (carbon fiber reinforced plastics overwrapped Al vessels. Explored internal pressure of nitrogen ranges from 1 bar to 300 bar and impact velocity are around 4400 m/s. Data obtained from Xrays radiographies and particle velocity measurements show the evolution of debris cloud and shock wave propagation in pressurized nitrogen. Observation of recovered vessels leads to the damage pattern and to its evolution as a function of the internal pressure. It is shown that the rupture mode is not a bursting mode but rather a catastrophic damage of the external carbon composite part of the vessel.

  1. Vulnerability analysis of a pressurized aluminum composite vessel against hypervelocity impacts

    Science.gov (United States)

    Hereil, Pierre-Louis; Plassard, Fabien; Mespoulet, Jérôme

    2015-09-01

    Vulnerability of high pressure vessels subjected to high velocity impact of space debris is analyzed with the response of pressurized vessels to hypervelocity impact of aluminum sphere. Investigated tanks are CFRP (carbon fiber reinforced plastics) overwrapped Al vessels. Explored internal pressure of nitrogen ranges from 1 bar to 300 bar and impact velocity are around 4400 m/s. Data obtained from Xrays radiographies and particle velocity measurements show the evolution of debris cloud and shock wave propagation in pressurized nitrogen. Observation of recovered vessels leads to the damage pattern and to its evolution as a function of the internal pressure. It is shown that the rupture mode is not a bursting mode but rather a catastrophic damage of the external carbon composite part of the vessel.

  2. Impact of pressure on physicochemical properties of starch dispersions

    KAUST Repository

    Yang, Zhi

    2016-09-02

    High hydrostatic pressure (HHP) can be employed as a non-thermal sterilization technique in the food industry while inducing structure and physicochemical changes of the food macromolecules like starch. The effect of HHP on starch depends on various factors including starch type and concentration, pressurization temperature, time, and suspending media. In this review, we summarize the influence of HHP on the structure, gelatinization, retrogradation, and modification of starches from different botanical origins. Suggestions for future research are provided to better understand the mechanism of HHP on starch, and on how HHP can be used in the starch industry. © 2016 Elsevier Ltd.

  3. Under Pressure: Financial Impact of the Hospital-Acquired Conditions Initiative. A Statewide Analysis of Pressure Ulcer Development and Payment

    Science.gov (United States)

    Meddings, Jennifer A.; Reichert, Heidi; Rogers, Mary A. M.; Hofer, Timothy P.; McMahon, Laurence F.; Grazier, Kyle L.

    2017-01-01

    OBJECTIVE To assess the financial impact of the 2008 Hospital-Acquired Conditions Initiative’s pressure ulcer payment changes on Medicare and other payors. DESIGN, SETTING AND PARTICIPANTS Retrospective before-and-after study of all-payor statewide administrative data for >2.4 million annual adult discharges from 311 nonfederal acute-care California hospitals in 2007 and 2009, using the Healthcare Cost and Utilization Project State Inpatient Datasets. We assessed how often and by how much the 2008 payment changes for pressure ulcers affected hospital payment. MEASUREMENTS Pressure ulcer rates and hospital payment changes RESULTS Hospital-acquired pressure ulcer rates were very low (0.28%) in 2007 and 2009; present-on-admission pressure ulcer rates increased from 2.35% in 2007 to 3.00% in 2009. By clinical stage of pressure ulcer (available in 2009), hospital-acquired stage III–IV ulcers occurred in 603 discharges (0.02%); 60,244 discharges (2.42%) contained other pressure ulcer diagnoses. Payment removal for stage III–IV hospital-acquired ulcers reduced payment in 75 (0.003%) discharges for a statewide payment decrease of $310,444 (0.001%) for all payors and $199,238 (0.001%) for Medicare. For all other pressure ulcers, the Hospital-Acquired Conditions Initiative reduced hospital payment in 20,246 (0.81%) cases (including 18,953 cases with present-on-admission ulcers) reducing statewide payment by $62,538,586 (0.21%) for all payors and $47,237,984 (0.32%) for Medicare. CONCLUSION The total financial impact of the 2008 payment changes for pressure ulcers was negligible. Most payment decreases occurred by removal of comorbidity payments for present-on-admission pressure ulcers other than stages III–IV. The removal of payment for hospital-acquired stage III–IV ulcers was more than 200 times less than the removal of payment for other types of pressure ulcers that occurred in implementation of the Hospital-Acquired Conditions Initiative. PMID:26140454

  4. Critical current retention of potted and unpotted REBCO Roebel cables under transverse pressure and thermal cycling

    Science.gov (United States)

    Talantsev, E. F.; Badcock, R. A.; Mataira, R.; Chong, S. V.; Bouloukakis, K.; Hamilton, K.; Long, N. J.

    2017-04-01

    Coated conductor Roebel cables are an effective way to create a high current density, fully transposed cable. However, despite REBCO tapes being robust against transverse stress, the Roebel architecture can concentrate transverse stress in non-trivial and random patterns depending on the exact arrangement of strands. If stands are embedded in a solid media which consolidates all strands then a transverse stress concentration will not occur. We tested this idea through mechanical and thermo-cycling tests on 5 strand Roebel cables. For non-impregnated cable irreversible degradation in critical currents is initiated at transverse pressures in a range of 4–34 MPa. Optical examination of the cables shows stress concentration patterns beyond those predicted by thickness variations. For cables impregnated with epoxy filled with SiO2 nanopowder, which has a similar thermal expansion coefficient to the metallic substrate of the strands, the irreversibility point is increased above our highest experimentally available pressure of 270 MPa. Thermo-cycling experiments confirmed a closely matched thermal expansion coefficient between the embedding media and metallic substrate is critical to avoid wire failures.

  5. Systematic impact of institutional pressures on safety climate in the construction industry.

    Science.gov (United States)

    He, Qinghua; Dong, Shuang; Rose, Timothy; Li, Heng; Yin, Qin; Cao, Dongping

    2016-08-01

    This paper explores how three types of institutional pressure (i.e., coercive, mimetic and normative pressures) systematically impact on the safety climate of construction projects. These impacts are empirically tested by survey data collected from 186 questionnaires of construction companies operating in Shanghai, China. The results, obtained by partial least squares analysis, show that organizational management commitment to safety and employee involvement is positively related to all three institutional pressures, while the perception of responsibility for safety and health is significantly influenced by coercive and mimetic pressure. However, coercive and normative pressures have no significant effect on the applicability of safety rules and work practices, revealing the importance of external organizational pressures in improving project safety climate from a systematic view. The findings also provide insights into the use of institutional forces to facilitate the improvement of safety climate in the construction industry.

  6. High pressure impact on changes in potato starch granules

    Directory of Open Access Journals (Sweden)

    Słomińska Lucyna

    2015-12-01

    Full Text Available Air dry potato starch (84.9% d.s. was subjected to pressurizing under the pressure of 50, 100, 250, 500, 750, 1000 and 2000 MPa for 1 h. The physical properties of pressurized starch, such as morphology, surface and crystalline structure, gelatinization parameters, were studied by means of scanning and atomic force microscopy (SEM/AFM, X-ray diffraction (X-ray, differential scanning calorimetry (DSC. The susceptibility to the amylolytic enzyme (α-amylase was also measured. Application of pressure in the range of 50–2000 MPa results in an increase in the compressed potato starch bulk density, change in the contours of the granules from oval to polyhedral, increase in the roughness of the granule surface, vanishing of the X-ray reflexes generated by the orthogonal structure and weakening of the reflexes generated by the hexagonal structure, lowering of the enthalpy of starch gelatinization, and the enhancement of hydrolytic susceptibility of starch granules to the amylolytic enzyme.

  7. Academic Pressure and Impact on Students' Development in China.

    Science.gov (United States)

    Lin, Jing; Zinghai, Chen

    1995-01-01

    Examines the enormous pressure Chinese students face at home and in school to obtain high academic achievement. Analyzes the cultural, economic, and political factors contributing to the situation. Concludes with an argument for balancing educational goals with other aspects of the students' lives. (MJP)

  8. [Impact of periodontal disease on arterial pressure in diabetic mice].

    Science.gov (United States)

    Blasco-Baque, V; Kémoun, P; Loubieres, P; Roumieux, M; Heymes, C; Serino, M; Sixou, M; Burcelin, R

    2012-06-01

    Diabetes-driven cardiovascular diseases represent a high challenge for developed countries. Periodontal disease is strictly linked to the aforementioned diseases, due to its Gram negative-driven inflammation. Thus, we investigated the effects of periodontal disease on arterial pressure during the development of diabetes in mice. To this aim, C57BL/6 female mice were colonized with pathogens of periodontal tissue (Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum) for 1month, whereas another group of mice did not undergo the colonization. Subsequently, all mice were fed a high-fat carbohydrate-free diet for 3months. Then, arterial pressure was measured in vivo and a tomodensitometric analysis of mandibles was realized as well. Our results show increased mandibular bone-loss induced by colonization with periopathogens. In addition, periodontal infection augmented glucose-intolerance and systolic and diastolic arterial pressure, parameters already known to be affected by a fat-diet. In conclusion, we show here that periodontal disease amplifies metabolic troubles and deregulates arterial pressure, emerging as a new axis of metabolic investigation.

  9. Impact of Physical Activity Interventions on Blood Pressure in Brazilian Populations

    OpenAIRE

    Vivian Freitas Rezende Bento; Flávia Barbizan Albino; Karen Fernandes de Moura; Gustavo Jorge Maftum; Mauro de Castro dos Santos; Luiz César Guarita-Souza; José Rocha Faria Neto; Cristina Pellegrino Baena

    2015-01-01

    Background: High blood pressure is associated with cardiovascular disease, which is the leading cause of mortality in the Brazilian population. Lifestyle changes, including physical activity, are important for lowering blood pressure levels and decreasing the costs associated with outcomes. Objective: Assess the impact of physical activity interventions on blood pressure in Brazilian individuals. Methods: Meta-analysis and systematic review of studies published until May 2014, retrieved from ...

  10. The Impact of Current Goals on Autobiographical Memories

    DEFF Research Database (Denmark)

    Johannessen, Kim Berg; Berntsen, Dorthe

    This symposium presents four studies that illustrate how cultural life scripts and collective transitions brought about by historical events have a strong impact on autobiographical remembering and the organization of autobiographical memories across the life span. Further, knowledge about...

  11. Scaling laws of impact induced shock pressure and particle velocity in planetary mantle

    Science.gov (United States)

    Monteux, J.; Arkani-Hamed, J.

    2016-01-01

    While major impacting bodies during accretion of a Mars type planet have very low velocities (propagation and, hence, the derived scaling laws are poorly known for these low velocity impacts. Here, we use iSALE-2D hydrocode simulations to calculate shock pressure and particle velocity in a Mars type body for impact velocities ranging from 4 to 10 km/s. Large impactors of 100-400 km in diameter, comparable to those impacted on Mars and created giant impact basins, are examined. To better represent the power law distribution of shock pressure and particle velocity as functions of distance from the impact site at the surface, we propose three distinct regions in the mantle: a near field regime, which extends to 1-3 times the projectile radius into the target, where the peak shock pressure and particle velocity decay very slowly with increasing distance, a mid field region, which extends to ∼4.5 times the impactor radius, where the pressure and particle velocity decay exponentially but moderately, and a more distant far field region where the pressure and particle velocity decay strongly with distance. These scaling laws are useful to determine impact heating of a growing proto-planet by numerous accreting bodies.

  12. Current Issues in LPP Research and Their Impact on Society

    Science.gov (United States)

    Darquennes, Jeroen

    2013-01-01

    After a very broad description of what language policy and planning is about this paper presents an overview of some of the current preoccupations of researchers focusing on language policy and planning as one of the blooming fields of applied linguistics. The current issues in language policy and planning research that are dealt with include…

  13. Can the use of pulsed direct current induce oscillation in the applied pressure during spark plasma sintering?

    Directory of Open Access Journals (Sweden)

    David Salamon, Mirva Eriksson, Mats Nygren and Zhijian Shen

    2012-01-01

    Full Text Available The spark plasma sintering (SPS process is known for its rapid densification of metals and ceramics. The mechanism behind this rapid densification has been discussed during the last few decades and is yet uncertain. During our SPS experiments we noticed oscillations in the applied pressure, related to a change in electric current. In this study, we investigated the effect of pulsed electrical current on the applied mechanical pressure and related changes in temperature. We eliminated the effect of sample shrinkage in the SPS setup and used a transparent quartz die allowing direct observation of the sample. We found that the use of pulsed direct electric current in our apparatus induces pressure oscillations with the amplitude depending on the current density. While sintering Ti samples we observed temperature oscillations resulting from pressure oscillations, which we attribute to magnetic forces generated within the SPS apparatus. The described current–pressure–temperature relations might increase understanding of the SPS process.

  14. Numerical simulation of a direct current glow discharge in atmospheric pressure helium

    Science.gov (United States)

    Yin, Zeng-Qian; Wang, Yan; Zhang, Pan-Pan; Zhang, Qi; Li, Xue-Chen

    2016-12-01

    Characteristics of a direct current (DC) discharge in atmospheric pressure helium are numerically investigated based on a one-dimensional fluid model. The results indicate that the discharge does not reach its steady state till it takes a period of time. Moreover, the required time increases and the current density of the steady state decreases with increasing the gap width. Through analyzing the spatial distributions of the electron density, the ion density and the electric field at different discharge moments, it is found that the DC discharge starts with a Townsend regime, then transits to a glow regime. In addition, the discharge operates in a normal glow mode or an abnormal glow one under different parameters, such as the gap width, the ballast resistors, and the secondary electron emission coefficients, judged by its voltage-current characteristics. Project supported by the National Natural Science Foundation of China (Grant Nos. 11575050 and 10805013), the Midwest Universities Comprehensive Strength Promotion Project, the Natural Science Foundation of Hebei Province, China (Grant Nos. A2016201042 and A2015201092), and the Research Foundation of Education Bureau of Hebei Province, China (Grant No. LJRC011).

  15. Burst Pressure Failure of Titanium Tanks Damaged by Secondary Plumes from Hypervelocity Impacts on Aluminum Shields

    Science.gov (United States)

    Nahra, Henry; Ghosn, Louis; Christiansen, Eric; Davis, B. Alan; Keddy, Chris; Rodriquez, Karen; Miller, Joshua; Bohl, William

    2011-01-01

    Metallic pressure tanks used in space missions are inherently vulnerable to hypervelocity impacts from micrometeoroids and orbital debris; thereby knowledge of impact damage and its effect on the tank integrity is crucial to a spacecraft risk assessment. This paper describes tests that have been performed to assess the effects of hypervelocity impact (HVI) damage on Titanium alloy (Ti-6Al-4V) pressure vessels burst pressure and characteristics. The tests consisted of a pair of HVI impact tests on water-filled Ti-6Al-4V tanks (water being used as a surrogate to the actual propellant) and subsequent burst tests as well as a burst test on an undamaged control tank. The tanks were placed behind Aluminum (Al) shields and then each was impacted with a 7 km/s projectile. The resulting impact debris plumes partially penetrated the Ti-6Al-4V tank surfaces resulting in a distribution of craters. During the burst tests, the tank that failed at a lower burst pressure did appear to have the failure initiating at a crater site with observed spall cracks. A fracture mechanics analysis showed that the tanks failure at the impact location may have been due to a spall crack that formed upon impact of a fragmentation on the Titanium surface. This result was corroborated with a finite element analysis from calculated Von-Mises and hoop stresses.

  16. Task Complexity and Time Pressure: Impacts on Activity-Travel Choices

    NARCIS (Netherlands)

    Chen, C.

    2014-01-01

    Task complexity and time pressure may have impacts on travellers’ choices in the context of highly synchronised mobility networks. However, it is unclear at the moment how these two aspects should be properly modelled simultaneously and what these impacts of the two aspects really are on travellers’

  17. Impact of pressure ulcers on quality of life in older patients: a systematic review.

    NARCIS (Netherlands)

    Gorecki, C.; Brown, J.M.; Nelson, E.A.; Briggs, M.; Schoonhoven, L.J.; Dealey, C.; Defloor, T.; Nixon, J.

    2009-01-01

    OBJECTIVES: To identify the impact of pressure ulcers (PUs) and PU interventions on health-related quality of life (HRQL). DESIGN: Systematic review and metasynthesis of primary research reporting the impact of PU and PU interventions on HRQL according to direct patient reports. Quality assessment

  18. Dependency of Tearing Mode Stability on Current and Pressure Profiles in DIII-D Hybrid Discharges

    Science.gov (United States)

    Kim, K.; Park, J. M.; Murakami, M.; La Haye, R. J.; Na, Y.-S.; SNU/ORAU; ORNL; Atomics, General; SNU; DIII-D Team

    2016-10-01

    Understanding the physics of the onset and evolution of tearing modes (TMs) in tokamak plasmas is important for high- β steady-state operation. Based on DIII-D steady-state hybrid experiments with accurate equilibrium reconstruction and well-measured plasma profiles, the 2/1 tearing mode can be more stable with increasing local current and pressure gradient at rational surface and with lower pressure peaking and plasma inductance. The tearing stability index Δ', estimated by the Rutherford equation with experimental mode growth rate was validated against Δ' calculated by linear eigenvalue solver (PEST3); preliminary comprehensive MHD modeling by NIMROD reproduced the TM onset reasonably well. We present a novel integrated modeling for the purpose of predicting TM onset in experiment by combining a model equilibrium reconstruction using IPS/FASTRAN, linear stability Δ' calculation using PEST3, and fitting formula for critical Δ' from NIMROD. Work supported in part by the US DoE under DE-AC05-06OR23100, DE-AC05-00OR22725, and DEFC02-04ER54698.

  19. Current Status of Development of High Nickel Low Alloy Steels for Commercial Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Chul; Lee, B. S.; Park, S. G.; Lee, K. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-12-15

    SA508 Gr.3 Mn-Mo-Ni low alloy steels have been used for nuclear reactor pressure vessel steels up to now. Currently, the design goal of nuclear power plant is focusing at larger capacity and longer lifetime. Requirements of much bigger pressure vessels may cause critical problems in the manufacturing stage as well as for the welding stage. Application of higher strength steel may be required to overcome the technical problems. It is known that a higher strength and fracture toughness of low alloy steels such as SA508 Gr.4N low alloy steel could be achieved by increasing the Ni and Cr contents. Therefore, SA508 Gr.4N low alloy steel is very attractive as eligible RPV steel for the next generation PWR systems. In this report, we propose the possibility of SA508 Gr.4N low alloy steel for an application of next generation commercial RPV, based on the literature research result about development history of the RPV steels and SA508 specification. In addition, we have surveyed the research result of HSLA(High Strength Low Alloy steel), which has similar chemical compositions with SA508 Gr.4N, to understand the problems and the way of improvement of SA508 Gr.4N low alloy steel. And also, we have investigated eastern RPV steel(WWER-1000), which has higher Ni contents compared to western RPV steel.

  20. Atmospheric pressure air direct current glow discharge ionization source for ion mobility spectrometry.

    Science.gov (United States)

    Dong, Can; Wang, Weiguo; Li, Haiyang

    2008-05-15

    A new atmospheric pressure air direct current glow discharge (DCGD) ionization source has been developed for ion mobility spectrometry (IMS) to overcome the regularity problems associated with the conventional (63)Ni source and the instability of the negative corona discharge. Its general electrical characteristics were experimentally investigated. By equipping it to IMS, a higher sensitivity was obtained compared to that of a (63)Ni source and corona discharge, and a linear dynamic range from 20 ppb to 20 ppm was obtained for m-xylene. Primary investigations showed that alkanes, such as pentane, which are nondetectable or insensitively detectable with (63)Ni-IMS, can be efficiently detected by DCGD-IMS and the detection limit of 10 ppb can be reached. The preliminary results have shown that the new DCGD ionization source has great potential applications in IMS, such as online monitoring of environment pollutants and halogenated compounds.

  1. Impact of lower body negative pressure induced hypovolemia on peripheral venous pressure waveform parameters in healthy volunteers.

    Science.gov (United States)

    Alian, Aymen A; Galante, Nicholas J; Stachenfeld, Nina S; Silverman, David G; Shelley, Kirk H

    2014-07-01

    Lower body negative pressure (LBNP) creates a reversible hypovolemia by sequestrating blood volume in the lower extremities. This study sought to examine the impact of central hypovolemia on peripheral venous pressure (PVP) waveforms in spontaneously breathing subjects. With IRB approval, 11 healthy subjects underwent progressive LBNP (baseline, -30, -75, and -90 mmHg or until the subject became symptomatic). Each was monitored for heart rate (HR), finger arterial blood pressure (BP), a chest respiratory band and PVP waveforms which are generated from a transduced upper extremity intravenous site. The first subject was excluded from PVP analysis because of technical errors in collecting the venous pressure waveform. PVP waveforms were analyzed to determine venous pulse pressure, mean venous pressure, pulse width, maximum and minimum slope (time domain analysis) together with cardiac and respiratory modulations (frequency domain analysis). No changes of significance were found in the arterial BP values at -30 mmHg LBNP, while there were significant reductions in the PVP waveforms time domain parameters (except for 50% width of the respiration induced modulations) together with modulation of the PVP waveform at the cardiac frequency but not at the respiratory frequency. As the LBNP progressed, arterial systolic BP, mean BP and pulse pressure, PVP parameters and PVP cardiac modulation decreased significantly, while diastolic BP and HR increased significantly. Changes in hemodynamic and PVP waveform parameters reached a maximum during the symptomatic phase. During the recovery phase, there was a significant reduction in HR together with a significant increase in HR variability, mean PVP and PVP cardiac modulation. Thus, in response to mild hypovolemia induced by LBNP, changes in cardiac modulation and other PVP waveform parameters identified hypovolemia before detectable hemodynamic changes.

  2. Life cycle assessment Part 2 : Current impact assessment practice

    NARCIS (Netherlands)

    Pennington, DW; Potting, J; Finnveden, G; Lindeijer, E; Jolliet, O; Rydberg, T; Rebitzer, G

    2004-01-01

    Providing our society with goods and services contributes to a wide range of environmental impacts. Waste generation, emissions and the consumption of resources occur at many stages in a product's life cycle-from raw material extraction, energy acquisition, production and manufacturing, use, reuse,

  3. Life cycle assessment Part 2 : Current impact assessment practice

    NARCIS (Netherlands)

    Pennington, DW; Potting, J; Finnveden, G; Lindeijer, E; Jolliet, O; Rydberg, T; Rebitzer, G

    2004-01-01

    Providing our society with goods and services contributes to a wide range of environmental impacts. Waste generation, emissions and the consumption of resources occur at many stages in a product's life cycle-from raw material extraction, energy acquisition, production and manufacturing, use, reuse,

  4. Life cycle assessment Part 2 : Current impact assessment practice

    NARCIS (Netherlands)

    Pennington, D.W; Potting, J; Finnveden, G; Lindeijer, E; Jolliet, O; Rydberg, T.; Rebitzer, G.

    Providing our society with goods and services contributes to a wide range of environmental impacts. Waste generation, emissions and the consumption of resources occur at many stages in a product's life cycle-from raw material extraction, energy acquisition, production and manufacturing, use, reuse,

  5. Little auks buffer the impact of current Arctic climate change

    DEFF Research Database (Denmark)

    Grémillet, David; Welcker, Jorg; Karnovsky, Nina J.

    2012-01-01

    Climate models predict a multi-degree warming of the North Atlantic in the 21st century. A research priority is to understand the impact of such changes upon marine organisms. With 40-80 million individuals, planktivorous little auks (Alle alle) are an essential component of pelagic food webs in ...

  6. AN EXPERIMENTAL INVESTIGATION ON THE IMPACT PERFORATION FAILURE OF WATER-FILLED-PRESSURIZED PIPELINES

    Institute of Scientific and Technical Information of China (English)

    LuGuoyun; LeiJianping; ZhangShanyuan

    2004-01-01

    Some experimental data recorded from impact tests on empty and water-filled pressurized mild steel pipes are presented. The pipes were supported as a three-span continuous beam and impacted laterally by a rigid indenter at the mid-span of middle span. Three kinds of indenter nose shapes were used: blunt-nose, hemisphere-nose and 90° conical-nose. The internal pressure ranged up to 20 MPa. The perforation failure modes and corresponding critical impact energies were obtained under different test conditions. The time-history curves of the internal pressure and impact force were given. The experiments show that the media filled in the tube greatly decreased the ballistic limit energy.

  7. Impact of pressure ulcers on individuals living with a spinal cord injury.

    Science.gov (United States)

    Lala, Deena; Dumont, Frédéric S; Leblond, Jean; Houghton, Pamela E; Noreau, Luc

    2014-12-01

    To describe the impact of pressure ulcers on the ability to participate in daily and community activities, health care utilization, and overall quality of life in individuals living with spinal cord injury (SCI). Cross-sectional study. Nationwide survey. Participants (N=1137) with traumatic SCI who were >1 year postinjury and living in the community were recruited. Of these, 381 (33.5%, 95% confidence interval, 30.8%-36.3%) had a pressure ulcer over the last 12 months. Not applicable. Measures developed for the Rick Hansen Spinal Cord Injury Registry Community Follow-up Survey Version 2.0. Of the 381 individuals with pressure ulcers, 65.3% reported that their pressure ulcer reduced their activity to some extent or more. Pressure ulcers reduced the ability of individuals with SCI to participate in 19 of 26 community and daily activities. Individuals with 1 or 2 pressure ulcers were more dissatisfied with their ability to participate in their main activity than those without pressure ulcers (P=.0077). Pressure ulcers were also associated with a significantly higher number of consultations with family doctors, nurses, occupational therapists, and wound care nurses/specialists (PPressure ulcers have a significant impact on the daily life of individuals with SCI. Our findings highlight the importance of implementing pressure ulcer prevention and management programs for this high-risk population and require the attention of all SCI-related health care professionals. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  8. The impact of sunlight on high-latitude equivalent currents

    CERN Document Server

    Laundal, K M; Østgaard, N; Reistad, J P; Haaland, S; Snekvik, K; Tenfjord, P; Ohtani, S; Milan, S E

    2016-01-01

    Ground magnetic field measurements can be mathematically related to an overhead ionospheric equivalent current. In this study we look in detail at how the global equivalent current, calculated using more than 30 years of SuperMAG magnetometer data, changes with sunlight conditions. The calculations are done using spherical harmonic analysis in quasi-dipole coordinates, a technique which leads to improved accuracy compared to previous studies. Sorting the data according to the location of the sunlight terminator and orientation of the interplanetary magnetic field (IMF), we find that the equivalent current resembles ionospheric convection patterns on the sunlit side of the terminator but not on the dark side. On the dark side, with southward IMF, the current is strongly dominated by a dawn cell and the current across the polar cap has a strong dawnward component. The contrast between the sunlit and dark side increases with increasing values of the $\\mathit{F}_{10.7}$ index, showing that increasing solar EUV fl...

  9. Evanescent high pressure during hypersonic cluster-surface impact characterized by the virial theorem.

    Science.gov (United States)

    Gross, A; Levine, R D

    2005-11-15

    Matter under extreme conditions can be generated by a collision of a hypersonic cluster with a surface. The ultra-high-pressure interlude lasts only briefly from the impact until the cluster shatters. We discuss the theoretical characterization of the pressure using the virial theorem and develop a constrained molecular-dynamics procedure to compute it. The simulations show that for rare-gas clusters the pressures reach the megabar range. The contribution to the pressure from momentum transfer is comparable in magnitude and is of the same sign as that ("the internal pressure") due to repulsive interatomic forces. The scaling of the pressure with the reduced mechanical variables is derived and validated with reference to the simulations.

  10. Heat transfer between two parallel porous plates for Couette flow under pressure gradient and Hall current

    Indian Academy of Sciences (India)

    Hazem A Attia; W Abbas; Mostafa A M Abdeen; Ahmed A M Said

    2015-02-01

    The aim of the present paper is to study the unsteady magneto-hydrodynamic viscous Couette flow with heat transfer in a Darcy porous medium between two infinite parallel porous plates considering Hall effect, and temperature dependent physical properties under constant pressure gradient. The parallel plates are assumed to be porous and subjected to a uniform suction from above and injection from below while the fluid is flowing through a porous medium that is assumed to obey Darcy’s law. A numerical solution for the governing nonlinear partial differential equations coupled with set of momentum equations and the energy equation including the viscous and Joule dissipations is adopted. The effect of the porosity of the medium, the Hall current and the temperature dependent viscosity and thermal conductivity on both the velocity and temperature distributions are investigated. It is found that the porosity numberMhas a marked effect on decreasing the velocity distribution (owing to a simultaneous increase in Darcy porous drag). Also the temperature T is decreased considerably with increasing porosity number.With increasing Hall current parameter m, the velocity component u (x-direction) is considerably increased, whereas velocity component w (z-direction) is reduced. Temperatures are decreased in the early stages of flow but effectively increased in the steady state with increasing m.

  11. Study of a new direct current atmospheric pressure glow discharge in helium

    Energy Technology Data Exchange (ETDEWEB)

    Gielniak, B. [University of Hamburg, Institute for Inorganic and Applied Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Fiedler, T. [Johannes Gutenberg-University Mainz, Institute for Inorganic and Analytical Chemistry, Duesbergweg 10-14, 55128 Mainz (Germany); Broekaert, J.A.C., E-mail: jose.broekaert@chemie.uni-hamburg.de [University of Hamburg, Institute for Inorganic and Applied Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)

    2011-01-15

    In this study a new DC-APGD operated in He was developed and characterized. The discharge is operated at 0.9 kV and about 25-35 mA and at a gas flow of 100 ml/min. The source was spectroscopically studied and parameters such as the rotational temperature (T{sub rot}), the excitation temperature (T{sub exc}), the ionization temperature (T{sub ion}) and the electron number density (n{sub e}) were determined. The current-voltage characteristic of the source was studied as well. At optimized conditions the discharge operates in the normal region of the current-voltage characteristic. Rotational and excitation temperatures determined with the use of OH band and Fe I lines as thermometric species were of the order of about 900-1200 and 4500-5500 K, respectively. This indicates that despite of the atmospheric pressure, the discharge is not in LTE. Spatially resolved temperature measurements were performed with axial as well as radial resolution and showed relatively flat profiles. Axially resolved emission intensity profiles for several species such as H, N{sub 2}, N{sub 2}{sup +}, OH, He and Hg were determined. It also was found that H{sub 2} introduced into the He by electrolysis of acid solutions such as in ECHG considerably increases the spectroscopically measured gas temperatures but decreases the analyte line intensities, as shown for Hg.

  12. Tyre Volume and Pressure Effects on Impact Attenuation during Mountain Bike Riding

    Directory of Open Access Journals (Sweden)

    Paul W. Macdermid

    2015-01-01

    Full Text Available Exposure to impacts and vibrations has been shown to be detrimental to cross country mountain bike performance and health. Therefore, any strategy aimed at attenuating such exposure is useful to participants and/or industry. The purpose of this study was to assess the influence of tyre size and tyre inflation pressure on exposure to impacts. Participants completed nine trials of a technical section (controlled for initial speed and route taken including nine separate conditions involving three tyre sizes and three tyre inflation pressures normalised per tyre. Performance was determined by time to negotiate the technical section while triaxial accelerometers recorded accelerations (128 Hz to quantify impact exposure and the subsequent effects on soft tissue response. Increases in tyre size within the range used improved performance P<0.0001 while changes to tyre inflation pressure had no effect P=0.6870 on performance. Larger tyre sizes and lower tyre inflation pressures significantly P<0.0001 reduced exposure to impacts which could be augmented or negated due to an interaction between tyre size and inflation pressure P<0.0001. It is recommended that mountain bikers use larger tyres, inflated to the moderate pressures used within this study, in order to increase performance and reduce the risk of overuse injuries.

  13. Current Mood vs. Recalled Impacts of Current Moods after Exposures to Sequences of Uncertain Monetary Outcomes

    Science.gov (United States)

    Olsson, Lars E.; Gärling, Tommy; Ettema, Dick; Friman, Margareta; Ståhl, Michael

    2017-01-01

    Events in a sequence may each be evaluated as good or bad. We propose that such good-bad evaluations evoke emotional responses that change current mood. A model of recurrent updating of current mood is developed and compared to a model of how a sequence of events evoking emotional responses is evaluated retrospectively. In Experiment 1, 149 undergraduates are presented sequences of lottery outcomes with a fixed probability of losing or winning different amounts of money. Ratings of current mood are made after the sequence. Retrospective evaluations are either made after the ratings of current mood or, in a control condition, when no ratings of current mood are made. The results show an expected effect on current mood of the valence of the end of the sequence. The results are less clear in showing an expected beginning effect on the retrospective evaluations. An expected beginning effect on retrospective evaluations is found in Experiment 2 in which 41 undergraduates are first asked to remember the different amounts of money, then to evaluate the sequence as lottery outcomes.

  14. Current Mood vs. Recalled Impacts of Current Moods after Exposures to Sequences of Uncertain Monetary Outcomes.

    Science.gov (United States)

    Olsson, Lars E; Gärling, Tommy; Ettema, Dick; Friman, Margareta; Ståhl, Michael

    2017-01-01

    Events in a sequence may each be evaluated as good or bad. We propose that such good-bad evaluations evoke emotional responses that change current mood. A model of recurrent updating of current mood is developed and compared to a model of how a sequence of events evoking emotional responses is evaluated retrospectively. In Experiment 1, 149 undergraduates are presented sequences of lottery outcomes with a fixed probability of losing or winning different amounts of money. Ratings of current mood are made after the sequence. Retrospective evaluations are either made after the ratings of current mood or, in a control condition, when no ratings of current mood are made. The results show an expected effect on current mood of the valence of the end of the sequence. The results are less clear in showing an expected beginning effect on the retrospective evaluations. An expected beginning effect on retrospective evaluations is found in Experiment 2 in which 41 undergraduates are first asked to remember the different amounts of money, then to evaluate the sequence as lottery outcomes.

  15. Nonlocal impacts of the Loop Current on cross-slope near-bottom flow in the northeastern Gulf of Mexico

    Science.gov (United States)

    Nguyen, Thanh-Tam; Morey, Steven L.; Dukhovskoy, Dmitry S.; Chassignet, Eric P.

    2015-04-01

    Cross-slope near-bottom motions near De Soto Canyon in the northeastern Gulf of Mexico are analyzed from a multidecadal ocean model simulation to characterize upwelling and downwelling, important mechanisms for exchange between the deep ocean and shelf in the vicinity of the 2010 BP Macondo well oil spill. Across the continental slope, large-scale depression and offshore movement of isopycnals (downwelling) occur more frequently when the Loop Current impinges upon the West Florida Shelf slope farther south. Upwelling and onshore movement of isopycnals occurs with roughly the same likelihood regardless of Loop Current impingement on the slope. The remote influence of Loop Current on the De Soto Canyon region downwelling is a consequence of a high-pressure anomaly that extends along the continental slope emanating from the location of Loop Current impact.

  16. On the impact of adverse pressure gradient on the supersonic turbulent boundary layer

    Science.gov (United States)

    Wang, Qian-Cheng; Wang, Zhen-Guo; Zhao, Yu-Xin

    2016-11-01

    By employing the particle image velocimetry, the mean and turbulent characteristics of a Mach 2.95 turbulent boundary layer are experimentally investigated without the impact of curvature. The physical mechanism with which the streamwise adverse pressure gradient affects the supersonic boundary layer is revealed. The data are compared to that of the concave boundary layer with similar streamwise distributions of wall static pressure to clarify the separate impacts of the adverse pressure gradient and the concave curvature. The logarithmic law is observed to be well preserved for both of the cases. The dip below the logarithmic law is not observed in present investigation. Theoretical analysis indicates that it could be the result of compromise between the opposite impacts of the compression wave and the increased turbulent intensity. Compared to the zero pressure gradient boundary layer, the principal strain rate and the turbulent intensities are increased by the adverse pressure gradient. The shear layer formed due the hairpin packets could be sharpened by the compression wave, which leads to higher principal strain rate and the associated turbulent level. Due to the additional impact of the centrifugal instability brought by the concave wall, even higher turbulent intensities than that of the adverse pressure gradient case are introduced. The existence of velocity modes within the zero pressure gradient boundary layer suggests that the large scale motions are statistically well organized. The generation of new velocity modes due to the adverse pressure gradient indicates that the turbulent structure is changed by the adverse pressure gradient, through which more turbulence production that cannot be effectively predicted by the Reynolds-stress transport equations could be brought.

  17. Impact of hydrostatic pressure on an intrinsically disordered protein: a high-pressure NMR study of α-synuclein.

    Science.gov (United States)

    Roche, Julien; Ying, Jinfa; Maltsev, Alexander S; Bax, Ad

    2013-09-23

    The impact of pressure on the backbone (15) N, (1) H and (13) C chemical shifts in N-terminally acetylated α-synuclein has been evaluated over a pressure range 1-2500 bar. Even while the chemical shifts fall very close to random coil values, as expected for an intrinsically disordered protein, substantial deviations in the pressure dependence of the chemical shifts are seen relative to those in short model peptides. In particular, the nonlinear pressure response of the (1) H(N) chemical shifts, which commonly is associated with the presence of low-lying "excited states", is much larger in α-synuclein than in model peptides. The linear pressure response of (1) H(N) chemical shift, commonly linked to H-bond length change, correlates well with those in short model peptides, and is found to be anticorrelated with its temperature dependence. The pressure dependence of (13) C chemical shifts shows remarkably large variations, even when accounting for residue type, and do not point to a clear shift in population between different regions of the Ramachandran map. However, a nearly universal decrease in (3) JHN-Hα by 0.22 ± 0.05 Hz suggests a slight increase in population of the polyproline II region at 2500 bar. The first six residues of N-terminally acetylated synuclein show a transient of approximately 15% population of α-helix, which slightly diminishes at 2500 bar. The backbone dynamics of the protein is not visibly affected beyond the effect of slight increase in water viscosity at 2500 bar.

  18. Impact of Hydrostatic Pressure on an Intrinsically Disordered Protein: A High-Pressure NMR Study of α-Synuclein [a

    Science.gov (United States)

    Roche, Julien; Ying, Jinfa; Maltsev, Alexander S.

    2013-01-01

    The impact of pressure on the backbone 15N, 1H and 13C chemical shifts in N-terminally acetylated α-synuclein has been evaluated over a pressure range spanning from 1–2500 bar. Even while the chemical shifts fall very close to random coil values, as expected for an intrinsically disordered protein, substantial deviations in the pressure dependence of the chemical shifts are seen relative to those in short model peptides. In particular, the non-linear pressure response of the 1HN chemical shifts, which commonly is associated with the presence of low-lying "excited states", is much larger in α-synuclein than in model peptides. The linear pressure response of 1HN chemical shift, commonly linked to H-bond length change, correlates well with those in short model peptides, and is found to be anti-correlated with its temperature dependence. The pressure dependence of 13C chemical shifts shows remarkably large variations, even when accounting for residue type, and do not point to a clear shift in population between different regions of the Ramachandran map. However, a nearly universal decrease in 3JHN-Hα by 0.22 ± 0.05 Hz suggests a slight increase in population of the polyproline II region at 2500 bar. The first six residues of N-terminally acetylated synuclein show a transient ca 15% population of α-helix, which slightly diminishes at 2500 bar. The backbone dynamics of the protein is not visibly affected beyond the effect of slight increase in water viscosity at 2500 bar. PMID:23813793

  19. Nausea: current knowledge of mechanisms, measurement and clinical impact.

    Science.gov (United States)

    Kenward, Hannah; Pelligand, Ludovic; Savary-Bataille, Karine; Elliott, Jonathan

    2015-01-01

    Nausea is a subjective sensation, which often acts as a signal that emesis is imminent. It is a widespread problem that occurs as a clinical sign of disease or as an adverse effect of a drug therapy or surgical procedure. The mechanisms of nausea are complex and the neural pathways are currently poorly understood. This review summarises the current knowledge of nausea mechanisms, the available animal models for nausea research and the anti-nausea properties of commercially available anti-emetic drugs. The review also presents subjective assessment and scoring of nausea. A better understanding of the underlying mechanisms of nausea might reveal potential clinically useful biomarkers for objective measurement of nausea in species of veterinary interest.

  20. The impact of relative humidity and atmospheric pressure on mortality in Guangzhou, China.

    Science.gov (United States)

    Ou, Chun Quan; Yang, Jun; Ou, Qiao Qun; Liu, Hua Zhang; Lin, Guo Zhen; Chen, Ping Yan; Qian, Jun; Guo, Yu Ming

    2014-12-01

    Although many studies have examined the effects of ambient temperatures on mortality, little evidence is on health impacts of atmospheric pressure and relative humidity. This study aimed to assess the impacts of atmospheric pressure and relative humidity on mortality in Guangzhou, China. This study included 213,737 registered deaths during 2003-2011 in Guangzhou, China. A quasi-Poisson regression with a distributed lag non-linear model was used to assess the effects of atmospheric pressure/relative humidity. We found significant effect of low atmospheric pressure/relative humidity on mortality. There was a 1.79% (95% confidence interval: 0.38%-3.22%) increase in non-accidental mortality and a 2.27% (0.07%-4.51%) increase in cardiovascular mortality comparing the 5th and 25th percentile of atmospheric pressure. A 3.97% (0.67%-7.39%) increase in cardiovascular mortality was also observed comparing the 5th and 25th percentile of relative humidity. Women were more vulnerable to decrease in atmospheric pressure and relative humidity than men. Age and education attainment were also potential effect modifiers. Furthermore, low atmospheric pressure and relative humidity increased temperature-related mortality. Both low atmospheric pressure and relative humidity are important risk factors of mortality. Our findings would be helpful to develop health risk assessment and climate policy interventions that would better protect vulnerable subgroups of the population. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  1. Moderate pressure has no distinct impact on hydrophobic hydration of proteins

    Energy Technology Data Exchange (ETDEWEB)

    Yegorov, Alexander Y.; Potekhin, Sergey A., E-mail: spot@vega.protres.ru

    2015-06-20

    Highlights: • Δc{sub p} is the heat capacity increment of any protein under denaturation. • We studied the effect of pressure on Δc{sub p} using a high pressure calorimeter. • Pressure has no impact on Δc{sub p} up to 178 MPa. • There is no noticeable pressure effect on hydration of unfolded proteins. - Abstract: The effect of high pressure on the change in the heat capacity (Δc{sub p}) of ribonuclease A and lysozyme upon denaturation has been studied using scanning microcalorimetry techniques. It has been shown that the pressure has no impact on Δc{sub p} up to 178 MPa, although appreciably varies the denaturation enthalpy. This result confirms the thermodynamic similarity of the denaturation process and the hydration degree of polypeptide chain in the denatured state at ambient and elevated pressure. Our findings are in conflict with some hypotheses concerning the high pressure effect on the structure stability of proteins.

  2. Drift in ocean currents impacts intergenerational microbial exposure to temperature.

    Science.gov (United States)

    Doblin, Martina A; van Sebille, Erik

    2016-05-17

    Microbes are the foundation of marine ecosystems [Falkowski PG, Fenchel T, Delong EF (2008) Science 320(5879):1034-1039]. Until now, the analytical framework for understanding the implications of ocean warming on microbes has not considered thermal exposure during transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Here we show that upper-ocean microbes experience along-trajectory temperature variability up to 10 °C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents can increase the thermal exposure of microbes and suggests that microbial populations with broad thermal tolerance will survive transport to distant regions of the ocean and invade new habitats. Our findings also suggest that advection has the capacity to influence microbial community assemblies, such that regions with strong currents and large thermal fluctuations select for communities with greatest plasticity and evolvability, and communities with narrow thermal performance are found where ocean currents are weak or along-trajectory temperature variation is low. Given that fluctuating environments select for individual plasticity in microbial lineages, and that physiological plasticity of ancestors can predict the magnitude of evolutionary responses of subsequent generations to environmental change [Schaum CE, Collins S (2014) Proc Biol Soc 281(1793):20141486], our findings suggest that microbial populations in the sub-Antarctic (∼40°S), North Pacific, and North Atlantic will have the most capacity to adapt to contemporary ocean warming.

  3. Current perspectives: the impact of cyberbullying on adolescent health

    OpenAIRE

    Nixon CL

    2014-01-01

    Charisse L Nixon Pennsylvania State University, the Behrend College, Erie, PA, USA Abstract: Cyberbullying has become an international public health concern among adolescents, and as such, it deserves further study. This paper reviews the current literature related to the effects of cyberbullying on adolescent health across multiple studies worldwide and provides directions for future research. A review of the evidence suggests that cyberbullying poses a threat to adolescents' health...

  4. Drift in ocean currents impacts intergenerational microbial exposure to temperature

    Science.gov (United States)

    Doblin, Martina A.; van Sebille, Erik

    2016-01-01

    Microbes are the foundation of marine ecosystems [Falkowski PG, Fenchel T, Delong EF (2008) Science 320(5879):1034–1039]. Until now, the analytical framework for understanding the implications of ocean warming on microbes has not considered thermal exposure during transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Here we show that upper-ocean microbes experience along-trajectory temperature variability up to 10 °C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents can increase the thermal exposure of microbes and suggests that microbial populations with broad thermal tolerance will survive transport to distant regions of the ocean and invade new habitats. Our findings also suggest that advection has the capacity to influence microbial community assemblies, such that regions with strong currents and large thermal fluctuations select for communities with greatest plasticity and evolvability, and communities with narrow thermal performance are found where ocean currents are weak or along-trajectory temperature variation is low. Given that fluctuating environments select for individual plasticity in microbial lineages, and that physiological plasticity of ancestors can predict the magnitude of evolutionary responses of subsequent generations to environmental change [Schaum CE, Collins S (2014) Proc Biol Soc 281(1793):20141486], our findings suggest that microbial populations in the sub-Antarctic (∼40°S), North Pacific, and North Atlantic will have the most capacity to adapt to contemporary ocean warming. PMID:27140608

  5. Environmental impacts of barley cultivation under current and future climatic conditions

    DEFF Research Database (Denmark)

    Dijkman, Teunis Johannes; Birkved, Morten; Saxe, Henrik

    2017-01-01

    The purpose of this work is to compare the environmental impacts of spring barley cultivation in Denmark under current (year 2010) and future (year 2050) climatic conditions. Therefore, a Life Cycle Assessment was carried out for the production of 1 kg of spring barley in Denmark, at farm gate......-products, the resulting environmental impacts were allocated between the main product and their respective by-products using economic allocation. Impact assessment was done using the ReCiPe (H) methodology, except for toxicity impacts, which were assessed using USEtox. The results show that the impacts for all impact...... for the increased impacts. This finding was confirmed by the sensitivity analysis. Because this study focused solely on the impacts of climate change, technological improvements and political measures to reduce impacts in the 2050 scenario are not taken into account. Options to mitigate the environmental impacts...

  6. Current Approaches Regarding the Knowledge Management Impact on SMEs Performance

    Directory of Open Access Journals (Sweden)

    Ionela Carmen RIZEA (PIRNEA

    2011-12-01

    Full Text Available Managing knowledge is a critical capability for small to medium-sized enterprises (SMEs to master because it helps them leverage their most critical resource. Organizational knowledge is the most salient resource at the disposal of SMEs in terms of availability, access, and depth. Successful SMEs are those who can leverage their knowledge in an effective and efficient manner, so as to make up for deficiencies in traditional resources, like land, labor, and capital. The purpose of this article is to identify the knowledge management impact on SMEs performance and to compare knowledge management in SMEs with knowledge management in large companies. The research discovered that SMEs do not manage knowledge the same way as larger organizations.

  7. Origins and impacts of mesoscale meanders in the Agulhas Current

    Science.gov (United States)

    Elipot, S.; Beal, L. M.

    2014-12-01

    The Agulhas Current (AC) is the western boundary current of the South Indian subtropical gyre and is also the pathway for the inter-basin exchange of water, heat and salt between the Indian Ocean and the Atlantic Ocean, and thus a crucial part of the global overturning circulation of the world ocean. The AC, which otherwise flows stably along the coast of South Africa, undergoes dramatic offshore excursions from its mean path, forming large mesoscale solitary meanders propagating downstream and potentially linked to the leakage of Indian Ocean waters to the South Atlantic. These irregular meander events have been referred to as Natal Pulses.Here we present new observations and analyses of Agulhas meanders using full-depth velocity mooring observations from the Agulhas Current Time series experiment (ACT). Detailed analyses of the in-situ velocity reveal important differences between the behavior of the flow during solitary meander events and during meander events of smaller amplitude. During solitary meanders, an onshore cyclonic circulation and an offshore anticyclonic circulation act in concert to displace the jet offshore, leading to sudden and strong positive conversion of kinetic energy of the mean flow to the meander. In contrast, smaller amplitude meanderings are principally represented by a single cyclonic circulation spanning the entire jet that acts to displace the jet without significantly extracting kinetic energy from the mean flow. Solitary meander events can be traced upstream using satellite altimetry and linked to either Mozambique Channel eddies or Madagascar dipoles, the latter possibly part of a basin-wide pattern of propagating sea level anomalies consistent with Rossby wave dynamics. However, only a small number of these anomalies lead to solitary meanders. Altimetric observations suggest 1.5 meanders per year and show that the two-year period during ACT when no events were observed is unprecedented in the 20-year satellite record.

  8. On the increase in the limiting current of an atmospheric-pressure glow discharge in an argon flow

    Science.gov (United States)

    Baldanov, B. B.; Ranzhurov, Ts. V.

    2014-04-01

    The initiation of an atmospheric-pressure glow discharge (APGD) is studied in the multitip cathode-planar anode electrode system through which an argon flow passes. It is shown that sectioning of the cathode and ballast resistances present at corona tips make it possible to substantially expand the current region of the discharge and considerably raise the limiting current of the APGD. The shape of the coronafree electrode is found to influence the limiting discharge current.

  9. Analysing the impact of urban pressures on agricultural land

    Science.gov (United States)

    Aksoy, Ece; Schröder, Christoph; Fons, Jaume; Gregor, Mirko; Louwagie, Geertrui

    2015-04-01

    Land, and here in particular soil, is a finite and essentially non-renewable resource. EU-wide, land take, i.e. the increase of settlement area over time, consumes more than 1000 km2 annually of which half is actually sealed and, hence, lost under impermeable surfaces. Land take and in particular soil sealing has already been identified as one of the major soil threats in the 2006 EC Communication 'Towards a Thematic Strategy on Soil Protection' (Soil Thematic Strategy), and has been confirmed as such in the report on the implementation of this strategy. The aim of this study is to relate the potential of land for a particle use in a given region with the actual land use. This allows evaluating whether land (in particular the soil dimension) is used according to its (theoretical) potential. To this aim, the impact of a number of land cover flows related to urban development on soils with a good, average and poor production potential were assessed and mapped. Thus, the amount and quality (potentials and/or suitability for agricultural production) of agricultural land lost between the years 2000 and 2006 was identified. In addition, areas with high productivity potential around urban areas indicating areas of potential future land use conflicts for Europe were identified.

  10. Optical emission spectroscopy diagnostics of an atmospheric pressure direct current microplasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Sismanoglu, B.N., E-mail: bogos@ita.b [Departamento de Fisica, Instituto Tecnologico de Aeronautica, Comando-Geral de Tecnologia Aeroespacial, Pca Marechal Eduardo Gomes 50, 12 228-900, Sao Jose dos Campos, SP (Brazil); Amorim, J., E-mail: jayr.amorim@bioetanol.org.b [Centro de Ciencia e Tecnologia do Bioetanol - CTBE, Caixa Postal 6170, 13083-970 Campinas, Sao Paulo (Brazil); Souza-Correa, J.A., E-mail: jorge.correa@bioetanol.org.b [Centro de Ciencia e Tecnologia do Bioetanol - CTBE, Caixa Postal 6170, 13083-970 Campinas, Sao Paulo (Brazil); Oliveira, C., E-mail: carlosf@ita.b [Departamento de Fisica, Instituto Tecnologico de Aeronautica, Comando-Geral de Tecnologia Aeroespacial, Pca Marechal Eduardo Gomes 50, 12 228-900, Sao Jose dos Campos, SP (Brazil); Gomes, M.P., E-mail: gomesmp@ita.b [Departamento de Fisica, Instituto Tecnologico de Aeronautica, Comando-Geral de Tecnologia Aeroespacial, Pca Marechal Eduardo Gomes 50, 12 228-900, Sao Jose dos Campos, SP (Brazil)

    2009-11-15

    This paper is about the use of optical emission spectroscopy as a diagnostic tool to determine the gas discharge parameters of a direct current (98% Ar-2% H{sub 2}) non-thermal microplasma jet, operated at atmospheric pressure. The electrical and optical behaviors were studied to characterize this glow discharge. The microplasma jet was investigated in the normal and abnormal glow regimes, for current ranging from 10 to 130 mA, at approx 220 V of applied voltage for copper cathode. OH (A {sup 2}SIGMA{sup +}, nu = 0 -> X {sup 2}PI, nu' = 0) rotational bands at 306.357 nm and also the 603.213 nm Ar I line, which is sensitive to van der Waals broadening, were used to determine the gas temperature, which ranges from 550 to 800 K. The electron number densities, ranging from 6.0 x 10{sup 14} to 1.4 x 10{sup 15} cm{sup -3}, were determined through a careful analysis of the main broadening mechanisms of the H{sub beta} line. From both 603.213 nm and 565.070 nm Ar I line broadenings, it was possible to obtain simultaneously electron number density and temperature (approx 8000 K). Excitation temperatures were also measured from two methods: from two Cu I lines and from Boltzmann-plot of 4p-4s and 5p-4s Ar I transitions. By employing H{sub alpha} line, the hydrogen atoms' H temperature was estimated (approx 18,000 K) and found to be surprisingly hotter than the excitation temperature.

  11. A Calculation Method for the Sloshing Impact Pressure Imposed on the Roof of a Passive Water Storage Tank of AP1000

    Directory of Open Access Journals (Sweden)

    Daogang Lu

    2016-01-01

    Full Text Available There is a large water storage tank installed at the top of containment of AP1000, which can supply the passive cooling. In the extreme condition, sloshing of the free surface in the tank may impact on the roof under long-period earthquake. For the safety assessment of structure, it is necessary to calculate the impact pressure caused by water sloshing. Since the behavior of sloshing impacted on the roof is involved into a strong nonlinear phenomenon, it is a little difficult to calculate such pressure by theoretical or numerical method currently. But it is applicable to calculate the height of sloshing in a tank without roof. In the present paper, a simplified method was proposed to calculate the impact pressure using the sloshing wave height, in which we first marked the position of the height of roof, then produced sloshing in the tank without roof and recorded the maximum wave height, and finally regarded approximately the difference between maximum wave height and roof height as the impact pressure head. We also designed an experiment to verify this method. The experimental result showed that this method overpredicted the impact pressure with a certain error of no more than 35%. By the experiment, we conclude that this method is conservative and applicable for the engineering design.

  12. Current perspectives: the impact of cyberbullying on adolescent health.

    Science.gov (United States)

    Nixon, Charisse L

    2014-01-01

    Cyberbullying has become an international public health concern among adolescents, and as such, it deserves further study. This paper reviews the current literature related to the effects of cyberbullying on adolescent health across multiple studies worldwide and provides directions for future research. A review of the evidence suggests that cyberbullying poses a threat to adolescents' health and well-being. A plethora of correlational studies have demonstrated a cogent relationship between adolescents' involvement in cyberbullying and negative health indices. Adolescents who are targeted via cyberbullying report increased depressive affect, anxiety, loneliness, suicidal behavior, and somatic symptoms. Perpetrators of cyberbullying are more likely to report increased substance use, aggression, and delinquent behaviors. Mediating/moderating processes have been found to influence the relationship between cyberbullying and adolescent health. More longitudinal work is needed to increase our understanding of the effects of cyberbullying on adolescent health over time. Prevention and intervention efforts related to reducing cyberbullying and its associated harms are discussed.

  13. Current perspectives: the impact of cyberbullying on adolescent health

    Science.gov (United States)

    Nixon, Charisse L

    2014-01-01

    Cyberbullying has become an international public health concern among adolescents, and as such, it deserves further study. This paper reviews the current literature related to the effects of cyberbullying on adolescent health across multiple studies worldwide and provides directions for future research. A review of the evidence suggests that cyberbullying poses a threat to adolescents’ health and well-being. A plethora of correlational studies have demonstrated a cogent relationship between adolescents’ involvement in cyberbullying and negative health indices. Adolescents who are targeted via cyberbullying report increased depressive affect, anxiety, loneliness, suicidal behavior, and somatic symptoms. Perpetrators of cyberbullying are more likely to report increased substance use, aggression, and delinquent behaviors. Mediating/moderating processes have been found to influence the relationship between cyberbullying and adolescent health. More longitudinal work is needed to increase our understanding of the effects of cyberbullying on adolescent health over time. Prevention and intervention efforts related to reducing cyberbullying and its associated harms are discussed. PMID:25177157

  14. Effects of carrier frequency of interferential current on pressure pain threshold and sensory comfort in humans.

    Science.gov (United States)

    Venancio, Roberta Ceila; Pelegrini, Stella; Gomes, Daiane Queiroz; Nakano, Eduardo Yoshio; Liebano, Richard Eloin

    2013-01-01

    To assess the effect of carrier frequency of interferential current (IFC) on pressure pain threshold (PPT) and sensory comfort in healthy subjects. A double-blind randomized trial. University research laboratory. Healthy subjects (N=150). Application of the IFC for 20 minutes and measures of PPT collected in the regions of the nondominant hand and forearm. We measured PPT and comfort at frequencies of 1kHz, 2kHz, 4kHz, 8kHz, and 10kHz. There was a significant increase in PPT in the 1-kHz group when compared with the 8-kHz and 10-kHz groups. There was a greater discomfort in the 1-kHz and 2-kHz groups. IFC with a carrier frequency of 1kHz promotes a higher hypoalgesic response during and after stimulation than IFC with carrier frequencies of 8kHz and 10kHz. Carrier frequencies of 1kHz and 2kHz are perceived as more uncomfortable than carrier frequencies of 4kHz, 8kHz, and 10kHz. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  15. Atmospheric pressure chemical ionization of explosives using alternating current corona discharge ion source.

    Science.gov (United States)

    Usmanov, D T; Chen, L C; Yu, Z; Yamabe, S; Sakaki, S; Hiraoka, K

    2015-04-01

    The high-sensitive detection of explosives is of great importance for social security and safety. In this work, the ion source for atmospheric pressure chemical ionization/mass spectrometry using alternating current corona discharge was newly designed for the analysis of explosives. An electromolded fine capillary with 115 µm inner diameter and 12 mm long was used for the inlet of the mass spectrometer. The flow rate of air through this capillary was 41 ml/min. Stable corona discharge could be maintained with the position of the discharge needle tip as close as 1 mm to the inlet capillary without causing the arc discharge. Explosives dissolved in 0.5 µl methanol were injected to the ion source. The limits of detection for five explosives with 50 pg or lower were achieved. In the ion/molecule reactions of trinitrotoluene (TNT), the discharge products of NOx (-) (x = 2,3), O3 and HNO3 originating from plasma-excited air were suggested to contribute to the formation of [TNT - H](-) (m/z 226), [TNT - NO](-) (m/z 197) and [TNT - NO + HNO3 ](-) (m/z 260), respectively. Formation processes of these ions were traced by density functional theory calculations. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Current Pressure Transducer Application of Model-based Prognostics Using Steady State Conditions

    Science.gov (United States)

    Teubert, Christopher; Daigle, Matthew J.

    2014-01-01

    Prognostics is the process of predicting a system's future states, health degradation/wear, and remaining useful life (RUL). This information plays an important role in preventing failure, reducing downtime, scheduling maintenance, and improving system utility. Prognostics relies heavily on wear estimation. In some components, the sensors used to estimate wear may not be fast enough to capture brief transient states that are indicative of wear. For this reason it is beneficial to be capable of detecting and estimating the extent of component wear using steady-state measurements. This paper details a method for estimating component wear using steady-state measurements, describes how this is used to predict future states, and presents a case study of a current/pressure (I/P) Transducer. I/P Transducer nominal and off-nominal behaviors are characterized using a physics-based model, and validated against expected and observed component behavior. This model is used to map observed steady-state responses to corresponding fault parameter values in the form of a lookup table. This method was chosen because of its fast, efficient nature, and its ability to be applied to both linear and non-linear systems. Using measurements of the steady state output, and the lookup table, wear is estimated. A regression is used to estimate the wear propagation parameter and characterize the damage progression function, which are used to predict future states and the remaining useful life of the system.

  17. Impact of Vehicle Class and Tire Pressure on Pavement Performance in MEPDG

    Directory of Open Access Journals (Sweden)

    Mohamed I. E. Attia

    2014-10-01

    Full Text Available The new Mechanistic-Empirical Pavement Design Guide (MEPDG design and analysis procedures defines the exact traffic loading by defining the specific number of each vehicle class and the use of axle load distribution factors instead of the equivalent single axle load (ESAL. The number of traffic inputs (parameters in MEPDG was found to be 17024. This research aimed to evaluate the sensitivity of the predicted flexible pavement distress to vehicle class and tire pressure in MEPDG. To evaluate the impact of vehicle (truck class on pavement sections, different cases of loading were analyzed. For each case, the MEPDG Ver. 1.1 was used to evaluate the effect of tire pressure by solving each case for a tire pressure of 120 and 140 psi. The effect of the traffic parameters on asphalt pavement (AC rutting, base rutting, subgrade rutting, international roughness index (IRI, longitudinal cracking and fatigue (alligator cracking were investigated. It was found that vehicle class distribution (VCD would cause clear impact (comparable to the effect of AADTT level only if the major traffic is of specific class (very light or very heavy. If this is not the case, the vehicle class distribution will not be a significant factor that affects the final design because most of the trucks had similar impact on flexible pavement distresses. The impact of tire pressure is clear on longitudinal cracking, fatigue cracking and AC rutting, and have no significant impact on both base and subgrade rutting.

  18. Renoprotection, renin inhibition, and blood pressure control: the impact of aliskiren on integrated blood pressure control

    Directory of Open Access Journals (Sweden)

    Haroon-Ur Rashid

    2010-10-01

    Full Text Available Haroon-Ur RashidDepartment of Cardiology, Baylor College of Medicine, Texas Heart Institute, Houston, TX, USAAbstract: Hypertension (HTN is an important factor in progressive loss of renal function. The kidney can be both a contributor to and a target of HTN. The functional integrity of the kidney is vital for the maintenance of cardiovascular homeostasis. Chronic activation of the renin system causes HTN and, ultimately, end-organ damage. Direct renin inhibitors (DRIs inhibit plasma renin activity (PRA, thereby preventing the conversion of angiotensinogen to angiotensin I; consequently, the levels of both Ang I and Ang II are reduced. There is no compensatory increase in PRA activity with DRIs as seen with angiotensin-converting enzyme inhibitors (ACEIs or angiotensin receptor blockers (ARBs. There are reasons to speculate that renin inhibition might prove to be a superior strategy for blocking the renin–angiotensin–aldosterone system compared with ACEIs or ARBs. Evidence for the efficacy of aliskiren (a DRI is considered to be relatively strong, based on published, short-term, double-blind, randomized, controlled trials showing that aliskiren is as effective as other antihypertensive agents in reducing blood pressure (BP, with no rebound effects on BP after treatment withdrawal. When combined with diuretics, fully additive BP reduction is seen. When given with an ACEI or ARB, aliskiren produces significant additional BP reduction indicative of complimentary pharmacology and more complete renin–angiotensin system blockade.Keywords: aliskiren, direct renin inhibitor, angiotensin-converting enzyme inhibitor, ACE inhibitor, angiotensin II receptor blocker, chronic kidney disease, hypertension, diabetes mellitus

  19. The current science of gastric banding: an overview of pressure-volume theory in band adjustments.

    Science.gov (United States)

    Fried, Martin

    2008-01-01

    Laparoscopic adjustable gastric banding (LAGB) is a safe and effective bariatric operation for the treatment of morbid obesity. Optimized long-term weight loss and reduced complications may be facilitated by development of a standardized, accurate, band-fill measurement methodology for use in postoperative LAGB adjustments. A summary of the primary in vitro, theoretical, and in vivo studies of pressure-volume theory relative to gastric banding was undertaken. LAGBs range in mechanisms of action from low-pressure/high-volume to high-pressure/low-volume. Use of both basic and dynamic pressure data obtained experimentally and clinically with a low-pressure/high-volume (LP/HV) band as a research tool revealed that intra-band pressures remained very low even when the band balloon was filled to its maximum fill volume; in contrast, when a high-pressure/low-volume (HP/LV) band was filled, it exhibited a pressure curve markedly steeper and of greater amplitude than that of the LP/HV band. Theoretical calculations of the differences between the bands in terms of the pressures they exerted on a bolus of food passing through a stoma found that the pressure created by the HP/LV band against the gastric wall was >100% higher than that applied by the LP/HV band; these mathematical results were verified by using invasive manometry in 35 patients undergoing band adjustment. In clinical testing, basic band pressure, band volume, and dynamic pressure data (that demonstrated esophageal motility patterns at the stoma during bolus passage) were gathered and correlated. As identified by intra-band pressure readings, a zone of disruptive peristaltic activity that obstructed bolus passage through the stoma was observed; slightly beneath this zone, it was hypothesized that successful patient adjustments might be carried out. The manometrically delineated measure of mean band pressure sufficient to exert a significant yet not disruptive restriction (i.e., 20 mm Hg; mean volume of 5.4 m

  20. Current perspectives: the impact of cyberbullying on adolescent health

    Directory of Open Access Journals (Sweden)

    Nixon CL

    2014-08-01

    Full Text Available Charisse L Nixon Pennsylvania State University, the Behrend College, Erie, PA, USA Abstract: Cyberbullying has become an international public health concern among adolescents, and as such, it deserves further study. This paper reviews the current literature related to the effects of cyberbullying on adolescent health across multiple studies worldwide and provides directions for future research. A review of the evidence suggests that cyberbullying poses a threat to adolescents' health and well-being. A plethora of correlational studies have demonstrated a cogent relationship between adolescents' involvement in cyberbullying and negative health indices. Adolescents who are targeted via cyberbullying report increased depressive affect, anxiety, loneliness, suicidal behavior, and somatic symptoms. Perpetrators of cyberbullying are more likely to report increased substance use, aggression, and delinquent behaviors. Mediating/moderating processes have been found to influence the relationship between cyberbullying and adolescent health. More longitudinal work is needed to increase our understanding of the effects of cyberbullying on adolescent health over time. Prevention and intervention efforts related to reducing cyberbullying and its associated harms are discussed. Keywords: cyberbullying, adolescent health, prevention, intervention

  1. Occupational status moderates the association between current perceived stress and high blood pressure: evidence from the IPC cohort study.

    Science.gov (United States)

    Wiernik, Emmanuel; Pannier, Bruno; Czernichow, Sébastien; Nabi, Hermann; Hanon, Olivier; Simon, Tabassome; Simon, Jean-Marc; Thomas, Frédérique; Bean, Kathy; Consoli, Silla M; Danchin, Nicolas; Lemogne, Cédric

    2013-03-01

    Although lay beliefs commonly relate high blood pressure (BP) to psychological stress exposure, research findings are conflicting. This study examined the association between current perceived stress and high BP, and explored the potential impact of occupational status on this association. Resting BP was measured in 122 816 adults (84 994 men), aged ≥30 years (mean age±standard deviation: 46.8±9.9 years), without history of cardiovascular and renal disease and not on either psychotropic or antihypertensive drugs. High BP was defined as systolic BP ≥140 mm Hg or diastolic BP ≥90 mm Hg. Perceived stress in the past month was measured with the 4-item perceived stress scale. A total of 33 154 participants (27.0%) had high BP (151±14/90±9 mm Hg). After adjustment for all variables except occupational status, perceived stress was associated with high BP (odds ratio [OR] for a 5-point increase: 1.06; 95% confidence interval [CI]: 1.03-1.09). This association was no longer significant after additional adjustment for occupational status (OR: 1.01; 95% CI: 0.99-1.04). There was a significant interaction (P<0.001) between perceived stress and occupational status in relation to BP: perceived stress was negatively associated with high BP among individuals of high occupational status (OR: 0.91; 95% CI: 0.87-0.96), but positively associated among those of low status (OR: 1.10; 95% CI: 1.03-1.17) or unemployed (OR: 1.13; 95% CI: 1.03-1.24). Sensitivity analyses yielded similar results. The association between current perceived stress and BP depends on occupational status. This interaction may account for previous conflicting results and warrants further studies to explore its underlying mechanisms.

  2. Effect of Stand-Off Distance on Impact Pressure of High Speed Water Jets

    Science.gov (United States)

    Sittiwong, Wuttichai; Seehanam, Wirapan; Pianthong, Kulachate; Matthujak, Anirut

    2010-06-01

    High speed liquid jets may be applied to jet cutting, drilling and cleaning. Recently, in the automotive industries, the spray injection pressure becomes higher and higher to enhance the fuel mixing for the improved combustion efficiency. However, the ultra high injection pressure may cause the damage to the nozzle and also the combustion chamber. In the medical application, the high speed liquid injection might be applied for the drug delivery through the skin where the needle is not required anymore. From the above mentioned application, the investigation on the impact pressure of the high speed liquid jet relative to the stand-off distant is significant. The high speed liquid jets are generated by the projectile impact driven method. The high speed projectile is launched by the horizontal single stage powder gun. The experimental study focuses on the stand-off between 1.5 cm to 6.0 cm, while the nozzle contains approximately 1.5cm3 of water in its cavity. The nozzle conical angles are 30° and 60° with the orifice diameter of 0.7 mm. The jet velocities are measured by laser beam interruptions method. The target material is the Polymethyl Methacrylate (PMMA) which the impact pressure is measured by using a piezoelectric Polyvinylidene Fluoride (PVDF) film. From the experiments, the maximum water jet velocity of 2290 m/s can be obtained from the 30° conical angle nozzle. The maximum impact pressures of nozzle conical angle of 30° and 60° are 3.4 GPa and 2.6 GPa respectively, at stand-off distance 3 cm. However, at the stand-off distance more than 3 cm, the impact pressure significantly decreases, because of aerodynamic drag, jets core break-up, and atomization of the water.

  3. In situ measurements of impact-induced pressure waves in sandstone targets

    Science.gov (United States)

    Hoerth, Tobias; Schäfer, Frank; Nau, Siegfried; Kuder, Jürgen; Poelchau, Michael H.; Thoma, Klaus; Kenkmann, Thomas

    2014-10-01

    In the present study we introduce an innovative method for the measurement of impact-induced pressure waves within geological materials. Impact experiments on dry and water-saturated sandstone targets were conducted at a velocity of 4600 m/s using 12 mm steel projectiles to investigate amplitudes, decay behavior, and speed of the waves propagating through the target material. For this purpose a special kind of piezoresistive sensor capable of recording transient stress pulses within solid brittle materials was developed and calibrated using a Split-Hopkinson pressure bar. Experimental impact parameters (projectile size and speed) were kept constant and yielded reproducible signal curves in terms of rise time and peak amplitudes. Pressure amplitudes decreased by 3 orders of magnitude within the first 250 mm (i.e., 42 projectile radii). The attenuation for water-saturated sandstone is higher compared to dry sandstone which is attributed to dissipation effects caused by relative motion between bulk material and interstitial water. The proportion of the impact energy radiated as seismic energy (seismic efficiency) is in the order of 10-3. The present study shows the feasibility of real-time measurements of waves caused by hypervelocity impacts on geological materials. Experiments of this kind lead to a better understanding of the processes in the crater subsurface during a hypervelocity impact.

  4. The impact of personality traits and professional experience on police officers' shooting performance under pressure

    NARCIS (Netherlands)

    Landman, A.; Nieuwenhuys, A.; Oudejans, R.R.D.

    2016-01-01

    We explored the impact of professional experience and personality on police officers' shooting performance under pressure. We recruited: (1) regular officers, (2) officers wanting to join a specialised arrest unit (AU) (expected to possess more stress-resistant traits; pre-AU) and (3) officers from

  5. The impact of personality traits and professional experience on police officers' shooting performance under pressure.

    Science.gov (United States)

    Landman, Annemarie; Nieuwenhuys, Arne; Oudejans, Raôul R D

    2016-07-01

    We explored the impact of professional experience and personality on police officers' shooting performance under pressure. We recruited: (1) regular officers, (2) officers wanting to join a specialised arrest unit (AU) (expected to possess more stress-resistant traits; pre-AU) and (3) officers from this unit (expected to also possess more professional experience; AU) (all male). In Phase 1, we determined personality traits and experience. In Phase 2, state anxiety, shot accuracy, decision-making (shoot/don't shoot), movement speed and gaze behaviour were measured while officers performed a shooting test under low and high pressure. Results indicate minimal differences in personality among groups and superior performance of AU officers. Regression analyses showed that state anxiety and shooting performance under high pressure were first predicted by AU experience and second by certain personality traits. Results suggest that although personality traits attenuate the impact of high pressure, it is relevant experience that secures effective performance under pressure. Practitioner Summary: To obtain information for police selection and training purposes, we let officers who differed in personality and experience execute a shooting test under low and high pressure. Outcomes indicate that experience affected anxiety and performance most strongly, while personality traits of thrill- and adventure-seeking and self-control also had an effect.

  6. Current developments in marine microbiology: high-pressure biotechnology and the genetic engineering of piezophiles.

    Science.gov (United States)

    Zhang, Yu; Li, Xuegong; Bartlett, Douglas H; Xiao, Xiang

    2015-06-01

    A key aspect of marine environments is elevated pressure; for example, ∼70% of the ocean is at a pressure of at least 38MPa. Many types of Bacteria and Archaea reside under these high pressures, which drive oceanic biogeochemical cycles and catalyze reactions among rocks, sediments and fluids. Most marine prokaryotes are classified as piezotolerant or as (obligate)-piezophiles with few cultivated relatives. The biochemistry and physiology of these organisms are largely unknown. Recently, high-pressure cultivation technology has been combined with omics and DNA recombination methodologies to examine the physiology of piezophilic marine microorganisms. We are now beginning to understand the adaptive mechanisms of these organisms, along with their ecological functions and evolutionary processes. This knowledge is leading to the further development of high-pressure-based biotechnology.

  7. A prospective study on the impact of peer and parental pressure on body dissatisfaction in adolescent girls and boys.

    Science.gov (United States)

    Helfert, Susanne; Warschburger, Petra

    2011-03-01

    The current study explores the role of appearance-related social pressure regarding changes in body image in adolescent girls (n=236) and boys (n=193) over a 1-year-period. High school students aged 11-16 completed measures of body dissatisfaction (i.e., weight and muscle concerns) and appearance-related social pressure from peers and parents. Three aspects proved to be particularly crucial: Parental encouragement to control weight and shape was a strong predictor of weight concerns in boys and girls alike; influences of friends affected gender-specific body image concerns by leading to weight concerns in girls and muscle concerns in boys; finally appearance-based exclusion was a predictor of weight concerns in boys. The findings provide longitudinal evidence for the crucial impact of appearance-related social pressure and suggest that a detailed assessment of different types of social impacts can identify concrete targets for effective prevention and therapy for weight-related problems among adolescents.

  8. Impacts of air pressure on the evolution of nanosecond pulse discharge products

    Institute of Scientific and Technical Information of China (English)

    Yu Jin-Lu; He Li-Ming; Ding Wei; Wang Yu-Qian; Du Chun

    2013-01-01

    Based on the nonequilibrium plasma dynamics of air discharge,a dynamic model of zero-dimensional plasma is established by combining the component density equation,the Boltzmann equation,and the energy transfer equation.The evolution properties of nanosecond pulse discharge (NPD) plasma under different air pressures are calculated.The results show that the air pressure has significant impacts on the NPD products and the peak values of particle number density for particles such as O atoms,O3 molecules,N2(A3) molecules in excited states,and NO molecules.It increases at first and then decreases with the increase of air pressure.On the other hand,the peak values of particle number density for N2(B3)and N2(C3) molecules in excited states are only slightly affected by the air pressure.

  9. System Impacts from Interconnection of Distributed Resources: Current Status and Identification of Needs for Further Development

    Energy Technology Data Exchange (ETDEWEB)

    Basso, T. S.

    2009-01-01

    This report documents and evaluates system impacts from the interconnection of distributed resources to transmission and distribution systems, including a focus on renewable distributed resource technologies. The report also identifies system impact-resolution approaches and actions, including extensions of existing approaches. Lastly, the report documents the current challenges and examines what is needed to gain a clearer understanding of what to pursue to better avoid or address system impact issues.

  10. Impact of physical activity interventions on blood pressure in Brazilian populations.

    Science.gov (United States)

    Bento, Vivian Freitas Rezende; Albino, Flávia Barbizan; Moura, Karen Fernandes de; Maftum, Gustavo Jorge; Santos, Mauro de Castro dos"; Guarita-Souza, Luiz César; Faria Neto, José Rocha; Baena, Cristina Pellegrino

    2015-09-01

    High blood pressure is associated with cardiovascular disease, which is the leading cause of mortality in the Brazilian population. Lifestyle changes, including physical activity, are important for lowering blood pressure levels and decreasing the costs associated with outcomes. Assess the impact of physical activity interventions on blood pressure in Brazilian individuals. Meta-analysis and systematic review of studies published until May 2014, retrieved from several health sciences databases. Seven studies with 493 participants were included. The analysis included parallel studies of physical activity interventions in adult populations in Brazil with a description of blood pressure (mmHg) before and after the intervention in the control and intervention groups. Of 390 retrieved studies, eight matched the proposed inclusion criteria for the systematic review and seven randomized clinical trials were included in the meta-analysis. Physical activity interventions included aerobic and resistance exercises. There was a reduction of -10.09 (95% CI: -18.76 to -1.43 mmHg) in the systolic and -7.47 (95% CI: -11.30 to -3.63 mmHg) in the diastolic blood pressure. Available evidence on the effects of physical activity on blood pressure in the Brazilian population shows a homogeneous and significant effect at both systolic and diastolic blood pressures. However, the strength of the included studies was low and the methodological quality was also low and/or regular. Larger studies with more rigorous methodology are necessary to build robust evidence.

  11. Impact of Physical Activity Interventions on Blood Pressure in Brazilian Populations

    Directory of Open Access Journals (Sweden)

    Vivian Freitas Rezende Bento

    2015-01-01

    Full Text Available Background: High blood pressure is associated with cardiovascular disease, which is the leading cause of mortality in the Brazilian population. Lifestyle changes, including physical activity, are important for lowering blood pressure levels and decreasing the costs associated with outcomes. Objective: Assess the impact of physical activity interventions on blood pressure in Brazilian individuals. Methods: Meta-analysis and systematic review of studies published until May 2014, retrieved from several health sciences databases. Seven studies with 493 participants were included. The analysis included parallel studies of physical activity interventions in adult populations in Brazil with a description of blood pressure (mmHg before and after the intervention in the control and intervention groups. Results: Of 390 retrieved studies, eight matched the proposed inclusion criteria for the systematic review and seven randomized clinical trials were included in the meta-analysis. Physical activity interventions included aerobic and resistance exercises. There was a reduction of -10.09 (95% CI: -18.76 to -1.43 mmHg in the systolic and -7.47 (95% CI: -11.30 to -3.63 mmHg in the diastolic blood pressure. Conclusions: Available evidence on the effects of physical activity on blood pressure in the Brazilian population shows a homogeneous and significant effect at both systolic and diastolic blood pressures. However, the strength of the included studies was low and the methodological quality was also low and/or regular. Larger studies with more rigorous methodology are necessary to build robust evidence.

  12. Plasma diagnostics and modeling of direct current microplasma discharges at atmospheric pressure

    Science.gov (United States)

    Wang, Qiang

    High pressure (100s of torr) microplasma (length scale 100s of micrometer) non-equilibrium discharges have potential applications as chemical microreactors, sensors, microelectromechanical systems (MEMS), and excimer radiation sources. Experimental and theoretical studies of these microplasmas can provide critical information on fundamental discharge characteristics, and help extend the window of stable discharge operation. Spatially resolved measurements (resolution ˜ 6 mum) were taken across a 200 mum slot-type microdischarge in atmospheric pressure helium or argon. Small amounts of actinometer gases were added to the flow for optical emission spectroscopy measurements. Gas temperature profiles were determined from N2 emission rotational spectroscopy. Stark splitting of the hydrogen Balmer-beta (Hbeta ) line was used to investigate the electric field distribution in the cathode sheath region. Electron densities were evaluated from the analysis of the spectral line broadenings of Hbeta emission. The measured gas temperature was in the range of 350--650 K in He, and 600--1200 K in Ar, both peaking near the cathode and increasing with power. The electron density in the bulk plasma was in the range (3-7)x1013 cm -3 in He, and (1-4)x1014 cm-3 in Ar. The measured electric field in He peaked at the cathode and decayed to small values over a distance of ˜50 mum (sheath edge) from the cathode. The experimental data were also used to validate a self-consistent one-dimensional plasma model. By a combination of measurements and simulation it was found that the dominant gas heating mechanism in DC microplasmas was ion Joule heating. Simulation results also predicted the existence of electric field reversals in the negative glow under operating conditions that favor a high electron diffusion flux emanating from the cathode sheath. The electric field adjusted to satisfy continuity of the total current. Also, the electric field in the anode layer was self adjusted to be

  13. Current Perspectives on the Use of Meditation to Reduce Blood Pressure

    Directory of Open Access Journals (Sweden)

    Carly M. Goldstein

    2012-01-01

    Full Text Available Meditation techniques are increasingly popular practices that may be useful in preventing or reducing elevated blood pressure. We reviewed landmark studies and recent literature concerning the use of meditation for reducing blood pressure in pre-hypertensive and hypertensive individuals. We sought to highlight underlying assumptions, identify strengths and weaknesses of the research, and suggest avenues for further research, reporting of results, and dissemination of findings. Meditation techniques appear to produce small yet meaningful reductions in blood pressure either as monotherapy or in conjunction with traditional pharmacotherapy. Transcendental meditation and mindfulness-based stress reduction may produce clinically significant reductions in systolic and diastolic blood pressure. More randomized clinical trials are necessary before strong recommendations regarding the use of meditation for high BP can be made.

  14. Water Resource Impacts Embedded in the Western US Electrical Energy Trade; Current Patterns and Adaptation to Future Drought

    Science.gov (United States)

    Adams, E. A.; Herron, S.; Qiu, Y.; Tidwell, V. C.; Ruddell, B. L.

    2013-12-01

    Water resources are a key element in the global coupled natural-human (CNH) system, because they are tightly coupled with the world's social, environmental, and economic subsystems, and because water resources are under increasing pressure worldwide. A fundamental adaptive tool used especially by cities to overcome local water resource scarcity is the outsourcing of water resource impacts through substitutionary economic trade. This is generally understood as the indirect component of a water footprint, and as ';virtual water' trade. This work employs generalized CNH methods to reveal the trade in water resource impacts embedded in electrical energy within the Western US power grid, and utilizes a general equilibrium economic trade model combined with drought and demand growth constraints to estimate the future status of this trade. Trade in embedded water resource impacts currently increases total water used for electricity production in the Western US and shifts water use to more water-limited States. Extreme drought and large increases in electrical energy demand increase the need for embedded water resource impact trade, while motivating a shift to more water-efficient generation technologies and more water-abundant generating locations. Cities are the largest users of electrical energy, and in the 21st Century will outsource a larger fraction of their water resource impacts through trade. This trade exposes cities to risks associated with disruption of long-distance transmission and distant hydrological droughts.

  15. Pressure vessel with impact and fire resistant coating and method of making same

    Science.gov (United States)

    DeLay, Thomas K. (Inventor)

    2005-01-01

    An impact and fire resistant coating laminate is provided which serves as an outer protective coating for a pressure vessel such as a composite overwrapped vessel with a metal lining. The laminate comprises a plurality of fibers (e.g., jute twine or other, stronger fibers) which are wound around the pressure vessel and an epoxy matrix resin for the fibers. The epoxy matrix resin including a plurality of microspheres containing a temperature responsive phase change material which changes phase in response to exposure thereof to a predetermined temperature increase so as to afford increased insulation and heat absorption.

  16. Current components, water pressure, physical, and other data from moored current meters, pressure gauges, and CTD casts from CHARTER/FISHING BOATS and other platforms from the Bering Sea - Coastal Waters of Western Alaska and other locations from 14 May 1989 to 06 October 1989 (NCEI Accession 9000278)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current components, water pressure, physical, and other data were collected from moored current meters, pressure gauges, and CTD casts from CHARTER/FISHING BOATS and...

  17. Real-time, whole-brain, temporally resolved pressure responses in translational head impact.

    Science.gov (United States)

    Zhao, Wei; Ji, Songbai

    2016-02-01

    Theoretical debate still exists on the role of linear acceleration ( a lin) on the risk of brain injury. Recent injury metrics only consider head rotational acceleration ( a rot) but not a lin, despite that real-world on-field head impacts suggesting a lin significantly improves a concussion risk function. These controversial findings suggest a practical challenge in integrating theory and real-world experiment. Focusing on tissue-level mechanical responses estimated from finite-element (FE) models of the human head, rather than impact kinematics alone, may help address this debate. However, the substantial computational cost incurred (runtime and hardware) poses a significant barrier for their practical use. In this study, we established a real-time technique to estimate whole-brain a lin-induced pressures. Three hydrostatic atlas pressures corresponding to translational impacts (referred to as 'brain print') along the three major axes were pre-computed. For an arbitrary a lin profile at any instance in time, the atlas pressures were linearly scaled and then superimposed to estimate whole-brain responses. Using 12 publically available, independently measured or reconstructed real-world a lin profiles representative of a range of impact/injury scenarios, the technique was successfully validated (except for one case with an extremely short impulse of approx. 1 ms). The computational cost to estimate whole-brain pressure responses for an entire a lin profile was less than 0.1 s on a laptop versus typically hours on a high-end multicore computer. These findings suggest the potential of the simple, yet effective technique to enable future studies to focus on tissue-level brain responses, rather than solely relying on global head impact kinematics that have plagued early and contemporary brain injury research to date.

  18. Giving in to Group Pressure: The Impact of Socialization and Risk on Perceived Outcomes

    Science.gov (United States)

    McIntyre, Katharine A.; Platania, Judith

    2009-01-01

    The current study applies the perspective of decision theory to understanding how choices are made in an in-group setting involving social pressure and risk. Two hundred sixty-one undergraduate students provided assessments of consequences associated with illegally consuming alcohol in different environments with differing degrees of risk. In…

  19. Research on resistance characteristics of YBCO tape under short-time DC large current impact

    Science.gov (United States)

    Zhang, Zhifeng; Yang, Jiabin; Qiu, Qingquan; Zhang, Guomin; Lin, Liangzhen

    2017-06-01

    Research of the resistance characteristics of YBCO tape under short-time DC large current impact is the foundation of the developing DC superconducting fault current limiter (SFCL) for voltage source converter-based high voltage direct current system (VSC-HVDC), which is one of the valid approaches to solve the problems of renewable energy integration. SFCL can limit DC short-circuit and enhance the interrupting capabilities of DC circuit breakers. In this paper, under short-time DC large current impacts, the resistance features of naked tape of YBCO tape are studied to find the resistance - temperature change rule and the maximum impact current. The influence of insulation for the resistance - temperature characteristics of YBCO tape is studied by comparison tests with naked tape and insulating tape in 77 K. The influence of operating temperature on the tape is also studied under subcooled liquid nitrogen condition. For the current impact security of YBCO tape, the critical current degradation and top temperature are analyzed and worked as judgment standards. The testing results is helpful for in developing SFCL in VSC-HVDC.

  20. Impacts of measurement protocols on blood pressure tracking from childhood into adulthood: a metaregression analysis.

    Science.gov (United States)

    Chen, Xiaoli; Wang, Youfa; Appel, Lawrence J; Mi, Jie

    2008-03-01

    The best approach for blood pressure (BP) measurement in children remains controversial, specifically regarding the choice of Korotkoff phase 4 versus Korotkoff phase 5 for diastolic BP (DBP) and the use of automated devices. To examine the impacts of different BP measurement protocols on BP tracking from childhood into adulthood, we conducted a meta-analysis of 50 related studies published between 1970 and 2006 identified based on a systematic search of PubMed. These studies provided 617 data points (tracking correlation coefficient, our outcome variable) for systolic BP and 547 data points for DBP for our meta-analysis. The explanatory variables included the use of Korotkoff phase 4/Korotkoff phase 5, BP device, and number of BP measurements per visit. Analyses were adjusted for potential confounders, including sex, baseline age, follow-up length, publication year, and study country. Tracking correlation coefficients for DBP measured using Korotkoff phase 4 was higher than that of Korotkoff phase 5 by 0.035 but not significant. DBP tracking assessed by automated device was higher than that of Korotkoff phase 5 by 0.152 (P=0.024) and higher than the mercury manometer by 0.223 (P=0.005). BP tracking was slightly higher with multiple BP measurements per visit, but measurements of >or=3 times did not improve the tracking further compared with 2 measurements. Although policy-making bodies currently recommend the use of Korotkoff phase 5 to assess DBP in children, our metaregression analysis did not support the recommendation. In general, Korotkoff phase 4 seems to be different from Korotkoff phase 5, and automated device is a promising approach for BP assessment in childhood.

  1. Imparting Barely Visible Impact Damage to a Stitched Composite Large-Scale Pressure Box

    Science.gov (United States)

    Lovejoy, Andrew E.; Przekop, Adam

    2016-01-01

    The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) is a concept that was developed by The Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body (HWB) aircraft configuration, which has been a focus of the NASA Environmentally Responsible Aviation Project. The NASA-Boeing structural development for the HWB aircraft culminated in testing of the multi-bay box, which is an 80%-scale representation of the pressurized center-body section. This structure was tested in the NASA Langley Research Center Combined Loads Test System facility. As part of this testing, barely visible impact damage was imparted to the interior and exterior of the test article to demonstrate compliance with a condition representative of the requirements for Category 1 damaged composite structure as defined by the Federal Aviation Regulations. Interior impacts were imparted using an existing spring-loaded impactor, while the exterior impacts were imparted using a newly designed, gravity-driven impactor. This paper describes the impacts to the test article, and the design of the gravitydriven guided-weight impactor. The guided-weight impactor proved to be a very reliable method to impart barely visible impact damage in locations which are not easily accessible for a traditional drop-weight impactor, while at the same time having the capability to be highly configurable for use on other aircraft structures.

  2. Impact of a Workplace Health Promotion Program on Employees' Blood Pressure in a Public University.

    Directory of Open Access Journals (Sweden)

    J Y Eng

    Full Text Available Workplace health promotion is important in the prevention of non-communicable diseases among employees. Previous workplace health programs have shown benefits such as lowered disease prevalence, reduced medical costs and improved productivity. This study aims to evaluate the impact of a 6-year workplace health promotion program on employees' blood pressure in a public university.In this prospective cohort study, we included 1,365 employees enrolled in the university's workplace health promotion program, a program conducted since 2008 and using data from the 2008-2013 follow-up period. Participants were permanent employees aged 35 years and above, with at least one follow up measurements and no change in antihypertensive medication during the study period. Baseline socio-demographic information was collected using a questionnaire while anthropometry measurements and resting blood pressure were collected during annual health screening. Changes in blood pressure over time were analyzed using a linear mixed model.The systolic blood pressure in the hypertension subgroup decreased 2.36 mmHg per year (p<0.0001. There was also significant improvement in systolic blood pressure among the participants who were at risk of hypertension (-0.75 mmHg, p<0.001. The diastolic blood pressure among the hypertensive and at risk subgroups improved 1.76 mmHg/year (p<0.001 and 0.56 mmHg/year (p<0.001, respectively. However, there was no change in both systolic and diastolic blood pressure among participants in the healthy subgroup over the 6-year period.This study shows that continuing participation in workplace health promotion program has the potential to improve blood pressure levels among employees.

  3. Remote sensing of cloud top pressure/height from SEVIRI: analysis of ten current retrieval algorithms

    Science.gov (United States)

    Hamann, U.; Walther, A.; Baum, B.; Bennartz, R.; Bugliaro, L.; Derrien, M.; Francis, P. N.; Heidinger, A.; Joro, S.; Kniffka, A.; Le Gléau, H.; Lockhoff, M.; Lutz, H.-J.; Meirink, J. F.; Minnis, P.; Palikonda, R.; Roebeling, R.; Thoss, A.; Platnick, S.; Watts, P.; Wind, G.

    2014-09-01

    The role of clouds remains the largest uncertainty in climate projections. They influence solar and thermal radiative transfer and the earth's water cycle. Therefore, there is an urgent need for accurate cloud observations to validate climate models and to monitor climate change. Passive satellite imagers measuring radiation at visible to thermal infrared (IR) wavelengths provide a wealth of information on cloud properties. Among others, the cloud top height (CTH) - a crucial parameter to estimate the thermal cloud radiative forcing - can be retrieved. In this paper we investigate the skill of ten current retrieval algorithms to estimate the CTH using observations from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) onboard Meteosat Second Generation (MSG). In the first part we compare ten SEVIRI cloud top pressure (CTP) data sets with each other. The SEVIRI algorithms catch the latitudinal variation of the CTP in a similar way. The agreement is better in the extratropics than in the tropics. In the tropics multi-layer clouds and thin cirrus layers complicate the CTP retrieval, whereas a good agreement among the algorithms is found for trade wind cumulus, marine stratocumulus and the optically thick cores of the deep convective system. In the second part of the paper the SEVIRI retrievals are compared to CTH observations from the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) and Cloud Profiling Radar (CPR) instruments. It is important to note that the different measurement techniques cause differences in the retrieved CTH data. SEVIRI measures a radiatively effective CTH, while the CTH of the active instruments is derived from the return time of the emitted radar or lidar signal. Therefore, some systematic differences are expected. On average the CTHs detected by the SEVIRI algorithms are 1.0 to 2.5 km lower than CALIOP observations, and the correlation coefficients between the SEVIRI and the CALIOP data sets range between 0.77 and 0.90. The

  4. Remote sensing of cloud top pressure/height from SEVIRI: analysis of ten current retrieval algorithms

    Directory of Open Access Journals (Sweden)

    U. Hamann

    2014-01-01

    Full Text Available The role of clouds remains the largest uncertainty in climate projections. They influence solar and thermal radiative transfer and the earth's water cycle. Therefore, there is an urgent need for accurate cloud observations to validate climate models and to monitor climate change. Passive satellite imagers measuring radiation at visible to thermal infrared wavelengths provide a wealth of information on cloud properties. Among others, the cloud top height (CTH – a crucial parameter to estimate the thermal cloud radiative forcing – can be retrieved. In this paper we investigate the skill of ten current retrieval algorithms to estimate the CTH using observations from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI onboard Meteosat Second Generation (MSG. In the first part we compare the ten SEVIRI cloud top pressure (CTP datasets with each other. The SEVIRI algorithms catch the latitudinal variation of the CTP in a similar way. The agreement is better in the extratropics than in the tropics. In the tropics multi-layer clouds and thin cirrus layers complicate the CTP retrieval, whereas good agreement is found for the cores of the deep convective system having a high optical depth. Furthermore, a good agreement between the algorithms is observed for trade wind cumulus and marine stratocumulus clouds. In the second part of the paper the SEVIRI retrievals are compared to CTH observations from the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP and Cloud Profiling Radar (CPR instruments. It is important to note that the different measurement techniques cause differences in the retrieved CHT data. SEVIRI measures a radiatively effective CTH, while the CTH of the active instruments is derived from the return time of the emitted signal. Therefore some systematic diffrences are expected. On average the CTHs detected by the SEVIRI algorithms are 1.0 to 2.5 km lower than CALIOP observations, and the correlation coefficients between the

  5. Remote sensing of cloud top pressure/height from SEVIRI: analysis of ten current retrieval algorithms

    Directory of Open Access Journals (Sweden)

    U. Hamann

    2014-09-01

    Full Text Available The role of clouds remains the largest uncertainty in climate projections. They influence solar and thermal radiative transfer and the earth's water cycle. Therefore, there is an urgent need for accurate cloud observations to validate climate models and to monitor climate change. Passive satellite imagers measuring radiation at visible to thermal infrared (IR wavelengths provide a wealth of information on cloud properties. Among others, the cloud top height (CTH – a crucial parameter to estimate the thermal cloud radiative forcing – can be retrieved. In this paper we investigate the skill of ten current retrieval algorithms to estimate the CTH using observations from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI onboard Meteosat Second Generation (MSG. In the first part we compare ten SEVIRI cloud top pressure (CTP data sets with each other. The SEVIRI algorithms catch the latitudinal variation of the CTP in a similar way. The agreement is better in the extratropics than in the tropics. In the tropics multi-layer clouds and thin cirrus layers complicate the CTP retrieval, whereas a good agreement among the algorithms is found for trade wind cumulus, marine stratocumulus and the optically thick cores of the deep convective system. In the second part of the paper the SEVIRI retrievals are compared to CTH observations from the Cloud–Aerosol LIdar with Orthogonal Polarization (CALIOP and Cloud Profiling Radar (CPR instruments. It is important to note that the different measurement techniques cause differences in the retrieved CTH data. SEVIRI measures a radiatively effective CTH, while the CTH of the active instruments is derived from the return time of the emitted radar or lidar signal. Therefore, some systematic differences are expected. On average the CTHs detected by the SEVIRI algorithms are 1.0 to 2.5 km lower than CALIOP observations, and the correlation coefficients between the SEVIRI and the CALIOP data sets range between

  6. Pressure Retarded Osmosis (PRO): Past experiences, current developments, and future prospects

    KAUST Repository

    Sarp, S.

    2016-01-16

    Pressure Retarded Osmosis (PRO) has attracted worldwide attention with respect to its salinity gradient energy production potential, and low energy desalination applications. PRO processes, which use Seawater Reverse Osmosis (SWRO) brine as draw solutions, have a higher potential of being applied to any new, and existing membrane based seawater desalination systems, as an energy production and/or conservation process. Hydraulic pressure is applied on a high salinity draw solution, and the hydraulic pressure of the high salinity draw solution can be kept relatively constant during operation, even though the volumetric flow rate is to be increased. Therefore, the draw side of the PRO process can be considered near-isobaric, in most cases. The harvested Gibbs free energy of mixing, and the volumetric expansion can explain this near-isobaric behavior of the draw side in the PRO process. Thus, PRO can be used to multiply the internal energy of the draw solution with respect to the ratio of the permeated water flux. Even though PRO has very high theoretical potential for energy production and/or recovery, there are several shortcomings, which should be answered before the realization of the scale up applications, such as; thermodynamic process optimization, high power density membranes, and high efficiency hydraulic pressure conversion and recovery systems. This review gives detailed information about the PRO process including; (1) theoretical background, (2) membranes for PRO, (3) experimental and large scale applications, and (4) economic feasibility of PRO applications.

  7. Arc Root Motions in an Argon-Hydrogen Direct-Current Plasma Torch at Reduced Pressure

    Institute of Scientific and Technical Information of China (English)

    HUANG He-Ji; PAN Wen-Xia; WU Cheng-Kang

    2008-01-01

    Arc root motions in generating dc argon hydrogen plasma at reduced pressure are optically observed using a high-speed video camera. The time resolved angular position of the arc root attachment point is measured and analysed. The arc root movement is characterized as a chaotic and jumping motion along the circular direction on the anode surface.

  8. Normal-pressure hydrocephalus: current understanding of diagnostic tests and shunting

    Energy Technology Data Exchange (ETDEWEB)

    Black, P.M.

    1982-02-01

    Normal-pressure hydrocephalus is no longer difficult to diagnose or treat-cranial computed tomographic scanning has made the diagnosis of ventricular enlargement straightforward, and shunt placement often helps the patient whose condition can be traced to a specific cause. Predicting accurately whether a patient will benefit from a shunt, however, is still problematic.

  9. Spatial Coherence of Impact Pressures at a Vertical Breakwater in Multidirectional Seas

    DEFF Research Database (Denmark)

    Sauer, W.; Löffler, A.; Kortenhaus, A.

    " (LSF) includes the possibility for researchers to work at selected European large-scale facilities. Within this activity the project "Spatial coherence of impact pressures at a vertical breakwater in multidirectional seas" was founded and could therefore be performed by the University of Bologna...... (DISTART Idraulica, Italy [UoB]), Aalborg University (Hydraulics and Coastal Engineering Laboratory, Denmark [AU]) and Technical University of Braunschweig (Leichtweiss-Institut, Germany [LWI])....

  10. Impact of current on static and kinetic depinning fields of domain wall in ferromagnetic nanostrip

    Indian Academy of Sciences (India)

    R Arun; P Sabareesan; M Daniel

    2015-11-01

    The impact of current on static and kinetic depinning fields of a domain wall in a onedimensional ferromagnetic nanostrip is investigated analytically and numerically by solving the Landau–Lifshitz–Gilbert equation with adiabatic and non-adiabatic spin-transfer torques. The results show that in the absence of current, the static depinning field is greater than the kinetic depinning field. Both the depinning fields decrease by increasing the current applied in a direction opposite to the direction of the applied field. Both the depinning fields can also be tuned by the current to make them equal.

  11. Remote field eddy current technique for gap measurement of horizontal flux detector guide tube in pressurized heavy water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Hoon; Jung, Hyun Kyu; Yang, Dong Ju; Cheong, Yong Moo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2004-11-15

    The fuel channels including the pressure tube(PT) and the calandria tube(CT) are important components of the pressurized heavy water reactor(PHWR). A sagging of fuel channel increases by heat and radiation exposure with the increasing operation time. The contact of fuel channel to the Horizontal flux Detector(HFD) guide tube is needed for the power plant safety. In order to solve this safety issue, the electromagnetic technique was applied to measure the status of the guide tube. The Horizontal flux Detector(HFD) guide tube and the Calandria tube(CT) in the Pressurized Heavy Water Reactor(PHWR) are cross-aligned horizontally. The remote field eddy current(RFEC) technology is applied for gap measurement between the HFD guide tube and the CT HFD guide tube can be detected by inserting the RFEC probe into pressure tube(PT) at the crossing point directly. The RFEC signals using the volume integral method(VIM) were simulated for obtaining the optimal inspection parameters. This paper shows that the simulated eddy current signals and the experimental results in variance with the CT/HFD gap.

  12. Impact of a Workplace Health Promotion Program on Employees' Blood Pressure in a Public University.

    Science.gov (United States)

    Eng, J Y; Moy, F M; Bulgiba, A

    2016-01-01

    Workplace health promotion is important in the prevention of non-communicable diseases among employees. Previous workplace health programs have shown benefits such as lowered disease prevalence, reduced medical costs and improved productivity. This study aims to evaluate the impact of a 6-year workplace health promotion program on employees' blood pressure in a public university. In this prospective cohort study, we included 1,365 employees enrolled in the university's workplace health promotion program, a program conducted since 2008 and using data from the 2008-2013 follow-up period. Participants were permanent employees aged 35 years and above, with at least one follow up measurements and no change in antihypertensive medication during the study period. Baseline socio-demographic information was collected using a questionnaire while anthropometry measurements and resting blood pressure were collected during annual health screening. Changes in blood pressure over time were analyzed using a linear mixed model. The systolic blood pressure in the hypertension subgroup decreased 2.36 mmHg per year (pworkplace health promotion program has the potential to improve blood pressure levels among employees.

  13. Magnetic diagnostics: general principles and the problem of reconstruction of plasma current and pressure profiles in toroidal systems

    Energy Technology Data Exchange (ETDEWEB)

    Pustovitov, V.D.

    2000-04-01

    The restrictions of the magnetic diagnostics are discussed. Being related to the integral nature of the measurable quantities, they follow from the fundamental laws of electromagnetism. A series of particular examples demonstrating the strength of these restrictions is given and analyzed. A general rule is emphasized that the information obtained from external magnetic measurements is obviously insufficient for the reliable evaluation of plasma current and pressure profiles in tokamaks or in stellarators. The underlying reason is that outside the plasma the own field of the equilibrium plasma currents is determined by the boundary conditions on the plasma surface only. (author)

  14. Effects of capillary discharge current on the time of lasing onset of soft x-ray laser at low pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Yongpeng; Cheng Yuanli; Luan Bohan; Wu Yinchu; Wang Qi [National Key Laboratory of Tunable Laser Technology, Harbin Institute of Technology, 150001 Harbin (China)

    2006-01-21

    The laser spike of Ne-like argon 46.9 nm pumped by a capillary discharge is measured with an x-ray diode (XRD) at low Ar pressure (25 Pa). Changing the rise-time and amplitude of the main current, we observe the effects of current on the time of the laser spike. The experimental results show that the time of lasing onset, which is the time of the laser spike after the onset of the main current, is larger than 40 ns and almost constant when the rise-time and amplitude of the current are changed. The theoretical results are calculated with the snow-plough model and show that the plasma is pinched several times before the laser spike occurs.

  15. Current meter and pressure gauge data from moored current meter casts and other instruments in the Gulf of Alaska as part of the Fisheries-Oceanography Cooperative Investigations (FOCI) project, 26 April 1989 - 26 September 1989 (NODC Accession 9100068)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter and pressure gauge data were collected using moored current meter casts and other instruments in the Gulf of Alaska from April 22, 1989 to September...

  16. [Current State of Diagnosis and Treatment of Idiopathic Normal Pressure Hydrocephalus].

    Science.gov (United States)

    Kazui, Hiroaki

    2016-04-01

    Idiopathic normal pressure hydrocephalus (iNPH) is a common disease with a prevalence of 1 to 3% in the elderly. The Japanese society of normal pressure hydrocephalus has developed clinical guidelines for the management of idiopathic normal pressure hydrocephalus and conducted two multicenter prospective studies for iNPH, which are called SINPHONI and SINPHONI-2. These guidelines define disproportionately enlarged subarachnoid space hydrocephalus (DESH) as iNPH with the specific MRI features of tight high-convexity, the presense of medial subarachnoid spaces and ventriculomegaly. Patients with DESH are known to be highly responsive to shunt surgery. Specifically, 60 to 70% of patients with DESH see improvements in their daily living activities following shunt surgery. While ventriculo-peritoneal shunt surgery (VPS) is most commonly used in western countries, lumbo-peritoneal shunt surgery (LPS) is increasingly used in Japan, as patients with iNPH and their caregivers are more willing to accept lumbar surgery than cranial surgery. LPS does not produce puncture-induced damage to the brain and has been recently confirmed to be effective for the treatment of iNPH. It is important for physicians to consider iNPH while examining patients with dementia, as iNPH is common, treatable, and easy to diagnose using MRI.

  17. Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes: principal results of the Conduit Artery Function Evaluation (CAFE) study.

    Science.gov (United States)

    Williams, Bryan; Lacy, Peter S; Thom, Simon M; Cruickshank, Kennedy; Stanton, Alice; Collier, David; Hughes, Alun D; Thurston, H; O'Rourke, Michael

    2006-03-07

    Different blood pressure (BP)-lowering drugs could have different effects on central aortic pressures and thus cardiovascular outcome despite similar effects on brachial BP. The Conduit Artery Function Evaluation (CAFE) study, a substudy of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT), examined the impact of 2 different BP lowering-regimens (atenolol+/-thiazide-based versus amlodipine+/-perindopril-based therapy) on derived central aortic pressures and hemodynamics. The CAFE study recruited 2199 patients in 5 ASCOT centers. Radial artery applanation tonometry and pulse wave analysis were used to derive central aortic pressures and hemodynamic indexes on repeated visits for up to 4 years. Most patients received combination therapy throughout the study. Despite similar brachial systolic BPs between treatment groups (Delta0.7 mm Hg; 95% CI, -0.4 to 1.7; P=0.2), there were substantial reductions in central aortic pressures with the amlodipine regimen (central aortic systolic BP, Delta4.3 mm Hg; 95% CI, 3.3 to 5.4; PCAFE cohort (unadjusted, P<0.0001; adjusted for baseline variables, P<0.05). BP-lowering drugs can have substantially different effects on central aortic pressures and hemodynamics despite a similar impact on brachial BP. Moreover, central aortic pulse pressure may be a determinant of clinical outcomes, and differences in central aortic pressures may be a potential mechanism to explain the different clinical outcomes between the 2 BP treatment arms in ASCOT.

  18. Sustained diffusive alternating current gliding arc discharge in atmospheric pressure air

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Li, Zhongshan

    2014-01-01

    current (AC) power source. The plasma column extended beyond the water-cooled stainless steel electrodes and was stabilized by matching the flow speed of the turbulent air jet with the rated output power. Comprehensive investigations were performed using high-speed movies measured over the plasma column......, synchronized with simultaneously recorded current and voltage waveforms. Dynamic details of the novel non-equilibrium discharge are revealed, which is characterized by a sinusoidal current waveform with amplitude stabilized at around 200 mA intermediate between thermal arc and glow discharge, shedding light...

  19. The Impact of Economic Pressure on Parent Positivity, Parenting, and Adolescent Positivity into Emerging Adulthood.

    Science.gov (United States)

    Neppl, Tricia K; Jeon, Shinyoung; Schofield, Thomas J; Donnellan, M Brent

    2015-02-01

    The current study describes how positivity can be incorporated into the Family Stress Model to explain resilience to disrupted family processes in the face of economic distress. Prospective, longitudinal data came from 451 mothers, fathers, and youth participating from their adolescence through early adulthood. Assessments included observational and self-report measures. Information regarding economic pressure, parental positivity, and parenting were collected during early adolescence, positivity was collected in late adolescence and emerging adulthood. Results indicated that economic pressure was indirectly associated with adolescent positivity through parental positivity. Economic pressure was negatively associated with parent positivity, whereas parental positivity was positively associated with parenting. Moreover, parental positivity and parenting were both related to positivity in adolescence. Results suggest that personal resources linked to a positive outlook can foster nurturant parenting, even in times of economic strain. Such parenting seems to positively influence adolescent development into emerging adulthood.

  20. The Integrity of the Corpus Callosum Mitigates the Impact of Blood Pressure on the Ventral Attention Network and Information Processing Speed in Healthy Adults

    Directory of Open Access Journals (Sweden)

    Tatia M. C. Lee

    2017-04-01

    Full Text Available Hypertension is a risk factor for cognitive impairment in older age. However, evidence of the neural basis of the relationship between the deterioration of cognitive function and elevated blood pressure is sparse. Based on previous research, we speculate that variations in brain connectivity are closely related to elevated blood pressure even before the onset of clinical conditions and apparent cognitive decline in individuals over 60 years of age. Forty cognitively healthy adults were recruited. Each received a blood pressure test before and after the cognitive assessment in various domains. Diffusion tensor imaging (DTI and resting-state functional magnetic resonance imaging (rsfMRI data were collected. Our findings confirm that elevated blood pressure is associated with brain connectivity variations in cognitively healthy individuals. The integrity of the splenium of the corpus callosum is closely related to individual differences in systolic blood pressure. In particular, elevated systolic blood pressure is related to resting-state ventral attention network (VAN and information processing speed. Serial mediation analyses have further revealed that lower integrity of the splenium statistically predicts elevated systolic blood pressure, which in turn predicts weakened functional connectivity (FC within the VAN and eventually poorer processing speed. The current study sheds light on how neural correlates are involved in the impact of elevated blood pressure on cognitive functioning.

  1. Type of mask may impact on continuous positive airway pressure adherence in apneic patients.

    Directory of Open Access Journals (Sweden)

    Jean Christian Borel

    Full Text Available RATIONALE: In obstructive sleep apnea patients (OSA, continuous positive airway pressure (CPAP adherence is crucial to improve symptoms and cardiometabolic outcomes. The choice of mask may influence CPAP adherence but this issue has never been addressed properly. OBJECTIVE: To evaluate the impact of nasal pillows, nasal and oronasal masks on CPAP adherence in a cohort of OSA. METHODS: Newly CPAP treated OSA participating in "Observatoire Sommeil de la Fédération de Pneumologie", a French national prospective cohort, were included between March 2009 and December 2011. Anthropometric data, medical history, OSA severity, sleepiness, depressive status, treatment modalities (auto-CPAP versus fixed pressure, pressure level, interface type, use of humidifiers and CPAP-related side effects were included in multivariate analysis to determine independent variables associated with CPAP adherence. RESULTS: 2311 OSA (age = 57(12 years, apnea+hypopnea index = 41(21/h, 29% female were included. Nasal masks, oronasal masks and nasal pillows were used by 62.4, 26.2 and 11.4% of the patients, respectively. In univariate analysis, oronasal masks and nasal pillows were associated with higher risk of CPAP non-adherence. CPAP non-adherence was also associated with younger age, female gender, mild OSA, gastroesophageal reflux, depression status, low effective pressure and CPAP-related side effects. In multivariate analysis, CPAP non-adherence was associated with the use of oronasal masks (OR = 2.0; 95%CI = 1.6; 2.5, depression, low effective pressure, and side effects. CONCLUSION: As oronasal masks negatively impact on CPAP adherence, a nasal mask should be preferred as the first option. Patients on oronasal masks should be carefully followed.

  2. Current management and future directions for the treatment of patients hospitalized for heart failure with low blood pressure.

    Science.gov (United States)

    Gheorghiade, Mihai; Vaduganathan, Muthiah; Ambrosy, Andrew; Böhm, Michael; Campia, Umberto; Cleland, John G F; Fedele, Francesco; Fonarow, Gregg C; Maggioni, Aldo P; Mebazaa, Alexandre; Mehra, Mandeep; Metra, Marco; Nodari, Savina; Pang, Peter S; Ponikowski, Piotr; Sabbah, Hani N; Komajda, Michel; Butler, Javed

    2013-03-01

    Although patients hospitalized with heart failure have relatively low in-hospital mortality, the post-discharge rehospitalization and mortality rates remain high despite advances in treatment. Most patients admitted for heart failure have normal or high blood pressure, but 15-25 % have low systolic blood pressure with or without signs and/or symptoms of hypoperfusion. All pharmacological agents known to improve the prognosis of patients with heart failure also reduce blood pressure, and this limits their use in patients with heart failure and low blood pressure (HF-LBP). However, patients with HF-LBP have much higher in-hospital and post-discharge mortality. In these patients, a conceptually important therapeutic target is to improve cardiac output in order to alleviate signs of hypoperfusion. Accordingly, the majority of these patients will require an inotrope as cardiac dysfunction is the cause of their low cardiac output. However, the short-term use of currently available inotropes has been associated with further decreases in blood pressure and increases in heart rate, myocardial oxygen consumption and arrhythmias. Agents that improve cardiac contractility without this undesirable effects should be developed. To the best of our knowledge, the epidemiology, pathophysiology and therapy of patients with HF-LBP have not been addressed thoroughly. In June 2010, a workshop that included scientists and clinicians was held in Rome, Italy. The objectives of this meeting were to (1) develop a working definition for HF-LBP, (2) describe its clinical characteristics and pathophysiology, (3) review current therapies and their limitations, (4) discuss novel agents in development and (5) create a framework for the design and conduct of future clinical trials.

  3. The Impact of Economic Pressure on Parent Positivity, Parenting, and Adolescent Positivity into Emerging Adulthood

    OpenAIRE

    Neppl, Tricia K.; Jeon, Shinyoung; Schofield, Thomas J.; Donnellan, M. Brent

    2015-01-01

    The current study describes how positivity can be incorporated into the Family Stress Model to explain resilience to disrupted family processes in the face of economic distress. Prospective, longitudinal data came from 451 mothers, fathers, and youth participating from their adolescence through early adulthood. Assessments included observational and self-report measures. Information regarding economic pressure, parental positivity, and parenting were collected during early adolescence, positi...

  4. Impact of biofilm accumulation on transmembrane and feed channel pressure drop: Effects of crossflow velocity, feed spacer and biodegradable nutrient

    KAUST Repository

    Dreszer, C.

    2014-03-01

    Biofilm formation causes performance loss in spiral-wound membrane systems. In this study a microfiltration membrane was used in experiments to simulate fouling in spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane modules without the influence of concentration polarization. The resistance of a microfiltration membrane is much lower than the intrinsic biofilm resistance, enabling the detection of biofilm accumulation in an early stage. The impact of biofilm accumulation on the transmembrane (biofilm) resistance and feed channel pressure drop as a function of the crossflow velocity (0.05 and 0.20ms-1) and feed spacer presence was studied in transparent membrane biofouling monitors operated at a permeate flux of 20Lm-2h-1. As biodegradable nutrient, acetate was dosed to the feed water (1.0 and 0.25mgL-1 carbon) to enhance biofilm accumulation in the monitors. The studies showed that biofilm formation caused an increased transmembrane resistance and feed channel pressure drop. The effect was strongest at the highest crossflow velocity (0.2ms-1) and in the presence of a feed spacer. Simulating conditions as currently applied in nanofiltration and reverse osmosis installations (crossflow velocity 0.2ms-1 and standard feed spacer) showed that the impact of biofilm formation on performance, in terms of transmembrane and feed channel pressure drop, was strong. This emphasized the importance of hydrodynamics and feed spacer design. Biomass accumulation was related to the nutrient load (nutrient concentration and linear flow velocity). Reducing the nutrient concentration of the feed water enabled the application of higher crossflow velocities. Pretreatment to remove biodegradable nutrient and removal of biomass from the membrane elements played an important part to prevent or restrict biofouling. © 2013 Elsevier Ltd.

  5. Potential impact of enhanced fracture-toughness data on fracture mechanics assessment of PWR vessel integrity for pressurized thermal shock

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, T.L.; Theiss, T.J.

    1991-01-01

    The Heavy Section Steel Technology (HSST) Program is involved with the generation of enhanced fracture-initiation toughness and fracture-arrest toughness data of prototypic nuclear reactor vessel steels. These two sets of data are enhanced because they have distinguishing characteristics that could potentially impact PWR pressure vessel integrity assessments for the pressurized-thermal shock (PTS) loading condition which is a major plant-life extension issue to be confronted in the 1990's. A series of large-scale fracture-mechanics experiments have produced crack-arrest (K{sub Ia}) data with the distinguishing characteristic that the values are considerably above 220 MPA {center dot} {radical}m. The implicit limit of the ASME Code and the limit used in the Integrated Pressurized Thermal Shock (IPTS) studies. Currently, the HSST Program is planning experiments to verify and quantify for A533B steel the distinguishing characteristic of elevated the distinguishing characteristic of elevated initiation-fracture toughness for shallow flaws which has been observed for other steels. The results of the analyses indicated that application of the enhanced K{sub Ia} data does reduce the conditional probability of failure P(F{vert bar}E); however, it does not appear to have the potential to significantly impact the results of PTS analyses. The application of enhanced fracture-initiation-toughness data for shallow flaws also reduces P(F{vert bar}E), and does appear to have a potential for significantly affecting the results of PTS analyses. 19 refs., 11 figs., 1 tab.

  6. The role of convection in the buildup of the ring current pressure during the 17 March 2013 storm

    Science.gov (United States)

    Menz, A. M.; Kistler, L. M.; Mouikis, C. G.; Spence, H. E.; Skoug, R. M.; Funsten, H. O.; Larsen, B. A.; Mitchell, D. G.; Gkioulidou, M.

    2017-01-01

    On 17 March 2013, the Van Allen Probes measured the H+ and O+ fluxes of the ring current during a large geomagnetic storm. Detailed examination of the pressure buildup during the storm shows large differences in the pressure measured by the two spacecraft, with measurements separated by only an hour, and large differences in the pressure measured at different local times. In addition, while the H+ and O+ pressure contributions are about equal during the main phase in the near-Earth plasma sheet outside L = 5.5, the O+ pressure dominates at lower L values. We test whether adiabatic convective transport from the near-Earth plasma sheet (L > 5.5) to the inner magnetosphere can explain these observations by comparing the observed inner magnetospheric distributions with the source distribution at constant magnetic moment, mu. We find that adiabatic convection can account for the enhanced pressure observed during the storm. Using a Weimer 1996 electric field we model the drift trajectories to show that the key features can be explained by variation in the near-Earth plasma sheet population and particle access that changes with energy and L shell. Finally, we show that the dominance of O+ at low L shells is due partly to a near-Earth plasma sheet that is preferentially enhanced in O+ at lower energies (5-10 keV) and partly due to the time dependence in the source combined with longer drift times to low L shells. No source of O+ inside L = 5.5 is required to explain the observations at low L shells.

  7. Current Situation of Household Income as a Factor, Having Impact on Mortgage Lending in Mongolia

    Directory of Open Access Journals (Sweden)

    Khuselchimeg Batbileg

    2012-04-01

    Full Text Available Amount of household income is the most important factor for housing loan. The article studies mortgage lending in Ulaanbaatar in 2007–2009, the factor, having great impact on the current economy of Mongolia, carries out the comparative analysis of capital’s medium and low income households and presents methods, which will help to solve these problems.

  8. Shared Solar. Current Landscape, Market Potential, and the Impact of Federal Securities Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brockway, Anna M. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Ulrich, Elaine [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-04-01

    This report provides a high-level overview of the current U.S. shared solar landscape and the impact that a given shared solar program’s structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.

  9. Shared Solar. Current Landscape, Market Potential, and the Impact of Federal Securities Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brockway, Anna M. [U.S. Department of Energy, Washington, DC (United States); Ulrich, Elaine [U.S. Department of Energy, Washington, DC (United States); Margolis, Robert [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-04-07

    This report provides a high-level overview of the current U.S. shared solar landscape, the impact that a given shared solar program’s structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.

  10. Investigating the Impacts of Previous and Current Learning Experiences on Student Teachers' Teaching Experiences

    Science.gov (United States)

    Ögeyik, Muhlise Cosgun

    2016-01-01

    This study investigated the impacts of the previous and current learning experiences of the student teachers on their microteaching practices. The study pursued threefold research goals: to diagnose the microteaching stance, to treat it, and to explore and evaluate the progress. The participants were 24 undergraduate third year student teachers…

  11. Biogeochemical and ecological impacts of boundary currents in the Indian Ocean

    Science.gov (United States)

    Hood, Raleigh R.; Beckley, Lynnath E.; Wiggert, Jerry D.

    2017-08-01

    Monsoon forcing and the unique geomorphology of the Indian Ocean basin result in complex boundary currents, which are unique in many respects. In the northern Indian Ocean, several boundary current systems reverse seasonally. For example, upwelling coincident with northward-flowing currents along the coast of Oman during the Southwest Monsoon gives rise to high productivity which also alters nutrient stoichiometry and therefore, the species composition of the resulting phytoplankton blooms. During the Northeast Monsoon most of the northern Indian Ocean boundary currents reverse and favor downwelling. Higher trophic level species have evolved behavioral responses to these seasonally changing conditions. Examples from the western Arabian Sea include vertical feeding migrations of a copepod (Calanoides carinatus) and the reproductive cycle of a large pelagic fish (Scomberomorus commerson). The impacts of these seasonal current reversals and changes in upwelling and downwelling circulations are also manifested in West Indian coastal waters, where they influence dissolved oxygen concentrations and have been implicated in massive fish kills. The winds and boundary currents reverse seasonally in the Bay of Bengal, though the associated changes in upwelling and productivity are less pronounced. Nonetheless, their effects are observed on the East Indian shelf as, for example, seasonal changes in copepod abundance and zooplankton community structure. In contrast, south of Sri Lanka seasonal reversals in the boundary currents are associated with dramatic changes in the intensity of coastal upwelling, chlorophyll concentration, and catch per unit effort of fishes. Off the coast of Java, monsoon-driven changes in the currents and upwelling strongly impact chlorophyll concentrations, seasonal vertical migrations of zooplankton, and sardine catch in Bali Strait. In the southern hemisphere the Leeuwin is a downwelling-favorable current that flows southward along western Australia

  12. Impact of nanoparticles on DNA repair processes: current knowledge and working hypotheses.

    Science.gov (United States)

    Carriere, Marie; Sauvaigo, Sylvie; Douki, Thierry; Ravanat, Jean-Luc

    2017-01-01

    The potential health effects of exposure to nanomaterials (NMs) is currently heavily studied. Among the most often reported impact is DNA damage, also termed genotoxicity. While several reviews relate the DNA damage induced by NMs and the techniques that can be used to prove such effects, the question of impact of NMs on DNA repair processes has never been specifically reviewed. The present review article proposes to fill this gap of knowledge by critically describing the DNA repair processes that could be affected by nanoparticle (NP) exposure, then by reporting the current state of the art on effects of NPs on DNA repair, at the level of protein function, gene induction and post-transcriptional modifications, and taking into account the advantages and limitations of the different experimental approaches. Since little is known about this impact, working hypothesis for the future are then proposed.

  13. Alternating current calorimeter for specific heat capacity measurements at temperatures below 10 K and pressures up to 10 GPa.

    Science.gov (United States)

    Umeo, Kazunori

    2016-06-01

    A developed alternating current calorimeter for measuring the absolute value of specific heat C of a very small sample under a pressure up to 10 GPa and low temperature below 10 K is described. A Bridgman anvil cell made of tungsten carbide with a top diameter of 3 mm is used. A hollow at the top prevents expansion of the sample space over the anvil top. Two chip resistors, which act as a thermometer and a heater, are mounted on the outer part of a copper-beryllium gasket with a frying pan-like shape. Thus, the thermometer is not pressurized. In order to isolate the gasket from the anvil thermally, diamond powder with a grain size of 0.25 μm is placed on the anvil top. Two jumps of C at the superconducting transitions of Pb (3.3 mg) and In (5.0 mg) are observed under various pressures up to 9 GPa, as clearly as those at the ambient pressure.

  14. Pressure impact of autoclave treatment on water sorption and pectin composition of flax cellulosic-fibres.

    Science.gov (United States)

    Alix, S; Colasse, L; Morvan, C; Lebrun, L; Marais, S

    2014-02-15

    The tensile properties of flax fibres might permit them to be used in composites as reinforcement in organic resin, as long as their mechanical properties are reproducible and their water sorption are reduced. In this study, to minimise the variability of mechanical properties, several samples of flax fibres were blended as a non-woven fabric. In order to reduce the water absorption of this non-woven technical fibres, an autoclave treatment was performed which was expected to remove the pectins and then to reduce the water sorption on their negative charges. The impact of autoclave pressure (0.5, 1 and 2 bars) on water sorption was investigated by using a gravimetric static equilibrium method. The Park model based on the three sorption modes: Langmuir, Henry's law and clustering, was successfully used to simulate the experimental sorption data. The lowest pressure treatments impacted only the Langmuir contribution while the 2 bar autoclave-treatment positively impacted the water resistance in the core of fibres by reducing Henry's absorption rate. This was shown to be related to the chemical modifications at the surface and in the core of fibres. A schematic model is presented relating the water sorption and the pectic composition of the fabric. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Predicting the behavioural impact of transcranial direct current stimulation: issues and limitations

    Directory of Open Access Journals (Sweden)

    Archy Otto De Berker

    2013-10-01

    Full Text Available The transcranial application of weak currents to the human brain has enjoyed a decade of success, providing a simple and powerful tool for non-invasively altering human brain function. However, our understanding of current delivery and its impact upon neural circuitry leaves much to be desired. We argue that the credibility of conclusions drawn with tDCS is contingent upon realistic explanations of how tDCS works, and that our present understanding of tDCS limits the technique’s use to localize function in the human brain. We outline two central issues where progress is required: the localization of currents, and predicting their functional consequence. We encourage experimenters to eschew simplistic explanations of mechanisms of transcranial current stimulation. We suggest the use of individualized current modelling, together with computational neurostimulation to inform mechanistic frameworks in which to interpret the physiological impact of tDCS. We hope that through mechanistically richer descriptions of current flow and action, insight into the biological processes by which transcranial currents influence behaviour can be gained, leading to more effective stimulation protocols and empowering conclusions drawn with tDCS.

  16. Investigating Premature Ignition of Thruster Pressure Cartridges by Mechanical Impact of Internal Components

    Science.gov (United States)

    Woods, Stephen S.; Saulsberry, Regor

    2010-01-01

    Pyrotechnic thruster pressure cartridges (TPCs) are used for aeroshell separation on a new NASA crew launch vehicle. The premature ignition concern was hypothesized based on the potential range of motion of the subassemblies, projected worst case accelerations, and the internal geometry that could subject propellant grains to mechanical impact sufficiently high for ignition. This possibility was investigated by fabricating a high-fidelity model of the suspected contact geometry, placing a representative amount of propellant in it, and impacting the propellant with a range of forces equivalent to and greater than the maximum possible during launch. Testing demonstrated that the likelihood of ignition is less than 1 in 1,000,000. The test apparatus, methodology, and results are described in this paper. Nondestructive evaluation ( NDE) during TPC acceptance testing indicated that internal assemblies moved during shock and vibration testing due to an internal bond anomaly. This caused concerns that the launch environment might produce the same movement and release propellant grains that might be prematurely ignited through impact or through electrostatic discharge (ESD) as grains vibrated against internal surfaces. Since a new lot could not be fabricated in time, a determination had to be made as to whether the lot was acceptable to fly. This paper discusses the analysis and impact testing used to address the potential impact issue and a separate paper addresses the ESD issue.

  17. [Current research of the excessive lateral pressure syndrome of patellofemoral joint].

    Science.gov (United States)

    Liu, Jin-song; Zhang, Dao-ping

    2011-05-01

    As modern medicine getting deeply to understand ever-detailed anatomy,structure and animal mechanics of the patellofemoral joint, excessive lateral pressure syndrome, a very common patellofemoral disorder, has been reacquainted by the clinicians. On account to the complexity and variety of the etiology and the mechanism of the pain, still, there are many difficulties and arguments on the exact description of the clinical symptoms and the establishment of a universally accepted diagnostic criteria. Accurately grasping different causes, pathomechanisms and developmental stages of the disease would be especially important. As a result, rational choice of the pertinent procedures become the clinical lynchpin. This paper reviews domestic and international pertinent literatures in the past 10 years, and provide an overview of the latest study of anatomy, biomechanic, pathomechanism and clinical experience, anticipating to offer help on standardizing the diagnosis and treatment of ELPS.

  18. Impact of home blood pressure telemonitoring and blood pressure control: a meta-analysis of randomized controlled studies.

    Science.gov (United States)

    Omboni, Stefano; Guarda, Alessia

    2011-09-01

    Home blood pressure telemonitoring figures among the possible solutions that could help improve blood pressure control of hypertensive patients. To summarize the effectiveness of home blood pressure telemonitoring on blood pressure control from randomized, controlled studies. Electronic databases were searched for publications in English, reporting on randomized trials of home blood pressure telemonitoring vs. usual care. Outcome measures were office or ambulatory blood pressure changes, rate of blood pressure control, and number of antihypertensive drugs used by patients. A random effects model was applied. Twelve studies met inclusion criteria. A high level of heterogeneity was found among studies for all the variables explored. Office blood pressure was reduced significantly more in patients randomized to home telemonitoring (systolic: 5.64 (95% confidence interval: 7.92, 3.36) mm Hg; diastolic: 2.78 (3.93, 1.62) mm Hg; 11 comparisons, n = 4,389). The effect on ambulatory blood pressure was smaller than on office blood pressure (systolic: 2.28 (4.32, 0.24); diastolic: 1.38 (3.55, +0.79) mm Hg; 3 comparisons, n = 655). The relative risk of blood pressure normalization (telemonitoring vs. the usual care group was 1.31 (1.06, 1.62) (5 comparisons, n = 2,432 subjects). Use of telemonitoring was associated with a significantly increased use of antihypertensive medications (+0.22 (+0.02, +0.43), 5 comparisons, n = 1,991). Home blood pressure telemonitoring may represent a useful tool to improve blood pressure control. However, heterogeneity of published studies suggests that well designed, large-scale, randomized, controlled studies are still needed to demonstrate the clinical usefulness of this technique.

  19. The Evolution of Current Research Impact Metrics: From Bibliometrics to Altmetrics?

    Science.gov (United States)

    Butler, Joseph S; Kaye, I David; Sebastian, Arjun S; Wagner, Scott C; Morrissey, Patrick B; Schroeder, Gregory D; Kepler, Christopher K; Vaccaro, Alexander R

    2017-03-23

    The prestige of publication has been based on traditional citation metrics, most commonly journal impact factor. However, the Internet has radically changed the speed, flow, and sharing of medical information. Furthermore, the explosion of social media, along with development of popular professional and scientific websites and blogs, has led to the need for alternative metrics, known as altmetrics, to quantify the wider impact of research. We explore the evolution of current research impact metrics and examine the evolving role of altmetrics in measuring the wider impact of research. We suggest that altmetrics used in research evaluation should be part of an informed peer-review process such as traditional metrics. Moreover, results based on altmetrics must not lead to direct decision making about research, but instead, should be used to assist experts in making decisions. Finally, traditional and alternative metrics should complement, not replace, each other in the peer-review process.

  20. Health Monitoring of Composite Overwrapped Pressure Vessels (COPVs) Using Meandering Winding Magnetometer ((MWM(Registered Trademark)) Eddy Current Sensors

    Science.gov (United States)

    Russell, Rick; Grundy, David; Jablonski, David; Martin, Christopher; Washabaugh, Andrew; Goldfine, Neil

    2011-01-01

    There are 3 mechanisms that affect the life of a COPV are: a) The age life of the overwrap; b) Cyclic fatigue of the metallic liner; c) Stress Rupture life. The first two mechanisms are understood through test and analysis. A COPV Stress Rupture is a sudden and catastrophic failure of the overwrap while holding at a stress level below the ultimate strength for an extended time. Currently there is no simple, deterministic method of determining the stress rupture life of a COPV, nor a screening technique to determine if a particular COPV is close to the time of a stress rupture failure. Conclusions: Demonstrated a correlation between MWM response and pressure or strain. Demonstrated the ability to monitor stress in COPV at different orientations and depths. FA41 provides best correlation with bottle pressure or stress.

  1. DMPD: Interferons at age 50: past, current and future impact on biomedicine. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18049472 Interferons at age 50: past, current and future impact on biomedicine. Bor...975-90. (.png) (.svg) (.html) (.csml) Show Interferons at age 50: past, current and future impact on biomedi...cine. PubmedID 18049472 Title Interferons at age 50: past, current and future imp

  2. Impact of the AT(2) receptor agonist C21 on blood pressure and beyond

    DEFF Research Database (Denmark)

    Foulquier, Sébastien; Steckelings, Ulrike Muscha; Unger, Thomas

    2012-01-01

    It is now widely accepted that the angiotensin AT(2) receptor (AT(2)R) plays an important protective role during pathophysiologic conditions, acting as a repair system. The development of the first selective nonpeptide AT(2)R agonist C21 accelerated our understanding of AT(2)R-mediated protective...... signaling and actions. This article reviews the impact of C21 on blood pressure in normotensive and hypertensive animal models. Although C21 does not act as a classical antihypertensive drug, it could be useful in preventing hypertension-induced vascular and other end organ damages via anti-apoptotic, anti...

  3. Pressure pain thresholds increase after preconditioning 1 Hz repetitive transcranial magnetic stimulation with transcranial direct current stimulation.

    Science.gov (United States)

    Moloney, Tonya M; Witney, Alice G

    2014-01-01

    The primary motor cortex (M1) is an effective target of non-invasive cortical stimulation (NICS) for pain threshold modulation. It has been suggested that the initial level of cortical excitability of M1 plays a key role in the plastic effects of NICS. Here we investigate whether transcranial direct current stimulation (tDCS) primed 1 Hz repetitive transcranial magnetic stimulation (rTMS) modulates experimental pressure pain thresholds and if this is related to observed alterations in cortical excitability. 15 healthy, male participants received 10 min 1 mA anodal, cathodal and sham tDCS to the left M1 before 15 min 1 Hz rTMS in separate sessions over a period of 3 weeks. Motor cortical excitability was recorded at baseline, post-tDCS priming and post-rTMS through recording motor evoked potentials (MEPs) from right FDI muscle. Pressure pain thresholds were determined by quantitative sensory testing (QST) through a computerized algometer, on the palmar thenar of the right hand pre- and post-stimulation. Cathodal tDCS-primed 1 Hz-rTMS was found to reverse the expected suppressive effect of 1 Hz rTMS on cortical excitability; leading to an overall increase in activity (p<0.001) with a parallel increase in pressure pain thresholds (p<0.01). In contrast, anodal tDCS-primed 1 Hz-rTMS resulted in a corresponding decrease in cortical excitability (p<0.05), with no significant effect on pressure pain. This study demonstrates that priming the M1 before stimulation of 1 Hz-rTMS modulates experimental pressure pain thresholds in a safe and controlled manner, producing a form of analgesia.

  4. Survival of fossilised diatoms and forams in hypervelocity impacts with peak shock pressures in the 1-19 GPa range

    Science.gov (United States)

    Burchell, M. J.; Harriss, K. H.; Price, M. C.; Yolland, L.

    2017-07-01

    Previously it has been shown that diatom fossils embedded in ice could survive impacts at speeds of up to 5 km s-1 and peak shock pressures up to 12 GPa. Here we confirm these results using a different technique, with diatoms carried in liquid water suspensions at impact speeds of 2-6 km s-1. These correspond to peak shock pressures of 3.8-19.8 GPa. We also report on the results of similar experiments using forams, at impact speeds of 4.67 km s-1 (when carried in water) and 4.73 km s-1 (when carried in ice), corresponding to peak shock pressures of 11.6 and 13.1 GPa respectively. In all cases we again find survival of recognisable fragments, with mean fragment size of order 20-25 μm. We compare our results to the peak shock pressures that ejecta from giant impacts on the Earth would experience if it subsequently impacted the Moon. We find that 98% of impacts of terrestrial ejecta on the Moon would have experienced peak pressures less than 20 GPa if the ejecta were a soft rock (sandstone). This falls to 82% of meteorites if the ejecta were a hard rock (granite). This assumes impacts on a solid lunar surface. If we approximate the surface as a loose regolith, over 99% of the impacts involve peak shock pressures below 20 GPa. Either way, the results show that a significant fraction of terrestrial meteorites impacting the Moon will do so with peak shock pressures which in our experiments permit the survival of recognisable fossil fragments.

  5. NASA's Current Evidence and Hypothesis for the Visual Impairment and Intracranial Pressure Risk

    Science.gov (United States)

    Otto, Christian A.; Norsk, Peter; Oubre, Cherie M.; Pass, Anastas F.; Tarver, William

    2012-01-01

    While 40 years of human spaceflight exploration has reported visual decrement to a certain extent in a subgroup of astronauts, recent data suggests that there is indeed a subset of crewmembers that experience refraction changes (hyperoptic shift), cotton wool spot formation, choroidal fold development, papilledema, optic nerve sheath distention and/or posterior globe flattening with varying degrees of severity and permanence. Pre and postflight ocular measures have identified a potential risk of permanent visual changes as a result of microgravity exposure, which has been defined as the Visual Impairment and Intracranial Pressure risk (VIIP). The combination of symptoms are referred to as the VIIP syndrome. It is thought that the ocular structural and optic nerve changes are caused by events precipitated by the cephalad fluid shift crewmembers experience during long-duration spaceflight. Three important systems, ocular, cardiovascular, and central nervous, seem to be involved in the development of symptoms, but the etiology is still under speculation. It is believed that some crewmembers are more susceptible to these changes due to genetic/anatomical predisposition or lifestyle (fitness) related factors. Future research will focus on determining the etiology of the VIIP syndrome and development of mechanisms to mitigate the spaceflight risk.

  6. Emission spectra from direct current and microwave powered Hg lamps at very high pressure

    Science.gov (United States)

    Hamady, M.; Lister, G. G.; Stafford, L.

    2013-11-01

    Discharge lamps containing mercury at pressures above 100 bar are commercially used in data projectors and television projector systems. Due to their small size, these lamps are difficult to investigate experimentally, but spectral measurements, combined with radiation transport calculations, have provided useful information on the visible spectrum. However, classical spectral line broadening theory is inadequate to describe the UV portion of the spectrum, so self-consistent modelling of these discharges is not possible at present. This paper discusses the differences between discharges containing electrodes and discharges sustained by a microwave (mw) electromagnetic field, on the basis of the experimentally measured temperature profile in an electroded discharge, and a temperature profile computed from a 1D power balance model for a microwave discharge. A model based on the ray-tracing method is employed to simulate the radiation transport in these lamps. The model has been validated by comparing the emission spectrum from dc discharge lamps with those obtained experimentally. The output flux, luminous flux, luminous efficacy, the correlated colour temperature, the chromaticity coordinates and photometric curves of the lamp were then obtained. These results were also compared with those of a theoretically calculated temperature profile for the same lamp, excited by microwave power in the TM010 mode.

  7. Antipodal Magnetic Anomalies on the Moon, Contributions from Impact Induced Currents Due to Positive Holes and Flexoelectric Phenomina and Dynamo

    Science.gov (United States)

    Kletetschka, G.; Freund, F.; Wasilewski, P. J.; Mikula, V.; Kohout, Tomas

    2005-01-01

    Large impacts on the Moon generate large pressure pulses that penetrate the whole body. Several of these large impacts may have generated antipodal structure with anomalous magnetic intensity.These regions can be more than a thousand km across, with fields of the order of tens to hundreds of nT. This is the case of Orientale, Imbrium, Serenitatis, Crisium, and Nectaris impact basins. The production of large-scale magnetic fields and associated crustal magnetization due to lunar basin-forming impacts was hypothesized to have an origin in fields external to the impact plasma cloud that are produced by the magnetohydrodynamic interaction of the cloud with ambient magnetic fields and plasmas. During the period of compressed antipodal field amplification, seismic compressional waves from the impact converge at the antipode resulting in transient shock pressures that reach 2 GPa (20 kbar). This can produce conditions for shock magnetic acquisition of the crust antipodal to impact basins.

  8. Riboflavin status, MTHFR genotype and blood pressure: current evidence and implications for personalised nutrition.

    Science.gov (United States)

    McAuley, E; McNulty, H; Hughes, C; Strain, J J; Ward, M

    2016-08-01

    Clinical deficiency of the B-vitamin riboflavin (vitamin B2) is largely confined to developing countries; however accumulating evidence indicates that suboptimal riboflavin status is a widespread problem across the developed world. Few international data are available on riboflavin status as measured by the functional biomarker, erythrocyte glutathione reductase activation coefficient, considered to be the gold standard index. One important role of riboflavin in the form of flavin dinucleotide is as a co-factor for the folate-metabolising enzyme methylenetetrahydrofolate reductase (MTHFR). Homozygosity for the common C677T polymorphism in MTHFR, affecting over 10 % of the UK and Irish populations and up to 32 % of other populations worldwide, has been associated with an increased risk of CVD, and more recently with hypertension. This review will explore available studies reporting riboflavin status worldwide, the interaction of riboflavin with the MTHFR C677T polymorphism and the potential role of riboflavin in personalised nutrition. Evidence is accumulating for a novel role of riboflavin as an important modulator of blood pressure (BP) specifically in individuals with the MTHFR 677TT genotype, with results from a number of recent randomised controlled trials demonstrating that riboflavin supplementation can significantly reduce systolic BP by 5-13 mmHg in these genetically at risk adults. Studies are however required to investigate the BP-lowering effect of riboflavin in different populations and in response to doses higher than 1·6 mg/d. Furthermore, work focusing on the translation of this research to health professionals and patients is also required.

  9. Analysis of Water Flow Pressure on Bridge Piers considering the Impact Effect

    Directory of Open Access Journals (Sweden)

    Yin-hui Wang

    2015-01-01

    Full Text Available In order to investigate the effects of water current impact and fluid-structure interaction on the bridge piers, the mechanism of water flow impact on the bridge pier is firstly studied. Then a finite element model of a bridge pier is established including the effects of water flow impact as well as the water circumferential motion around the pier. Comparative study is conducted between the results of water impact effect, fluid-structure coupling effect, theoretical analysis, and also the results derived using the formulas specified in the design codes home and abroad. The results show that the water flow force calculated using the formulas provided by the codes should be multiplied by an impact amplifier to account for the effect of flood impact on the bridge pier. When the flood flows around the pier, the fluid-structure coupling effect on the bridge pier can be neglected. The method specified in the China guidelines of General Code for Design of Highway Bridges and Culverts tends to provide a larger result of the water flow force.

  10. Impact of mesh tracks and low-ground-pressure vehicle use on blanket peat hydrology

    Science.gov (United States)

    McKendrick-Smith, Kathryn; Holden, Joseph; Parry, Lauren

    2016-04-01

    Peatlands are subject to multiple uses including drainage, farming and recreation. Low-ground-pressure vehicle access is desirable by land owners and tracks facilitate access. However, there is concern that such activity may impact peat hydrology and so granting permission for track installation has been problematic, particularly without evidence for decision-making. We present the first comprehensive study of mesh track and low-ground-pressure vehicle impacts on peatland hydrology. In the sub-arctic oceanic climate of the Moor House World Biosphere Reserve in the North Pennines, UK, a 1.5 km long experimental track was installed to investigate hydrological impacts. Surface vegetation was cut and the plastic mesh track pinned into the peat surface. The experimental track was split into 7 treatments, designed to reflect typical track usage (0 - 5 vehicle passes per week) and varying vehicle weight. The greatest hydrological impacts were expected for sections of track subject to more frequent vehicle use and in close proximity to the track. In total 554 dipwells (including 15 automated recording at 15-min intervals) were monitored for water-table depth, positioned to capture potential spatial variability in response. Before track installation, samples for vertical and lateral hydraulic conductivity (Ks) analysis (using the modified cube method) were taken at 0-10 cm depth from a frequently driven treatment (n = 15), an infrequently driven treatment (0.5 passes per week) (n = 15) and a control site with no track/driving (n = 15). The test was repeated after 16 months of track use. We present a spatially and temporally rich water-table dataset from the study site showing how the impacts of the track on water table are spatially highly variable. Water-table depths across the site were shallow, typically within the upper 10 cm of the peat profile for > 75% of the time. We show that mesh track and low-ground-pressure vehicle impacts on water-table depth were small except

  11. A global review of cumulative pressure and impact assessments in marine environment

    Directory of Open Access Journals (Sweden)

    Samuli Korpinen

    2016-08-01

    Full Text Available Ever more extensive use of marine space by human activities and greater demands for marine natural resources has led to increases in both duration and spatial extent of pressures on the marine environment. In parallel, the global crisis of decreasing biodiversity and loss of habitats has revitalized scientific research on human impacts and lead to methodological development of cumulative pressure and impact assessments (CPIA. In Europe alone, almost twenty CPIAs have been published in the past 10 years and some more in other sea regions of the world. In this review, we have analysed 36 recent marine CPIAs and focused on their methodological approaches. We were especially interested in uncovering methodological similarities, identifying best practices and analysing whether the CPIAs have addressed the recent criticism. The review results showed surprisingly similar methodological approaches in >50% of the studies, raising hopes for finding coherence in international assessment efforts. Although the CPIA methods showed relatively few innovative approaches for addressing the major caveats of previous CPIAs, the most recent studies indicate that improved approaches may be soon found.

  12. STRONG SOLAR WIND DYNAMIC PRESSURE PULSES: INTERPLANETARY SOURCES AND THEIR IMPACTS ON GEOSYNCHRONOUS MAGNETIC FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Pingbing; Feng, Xueshang; Wang, Yi [SIGMA Weather Group, State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Xie, Yanqiong [College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing (China); Xu, Xiaojun, E-mail: pbzuo@spaceweather.ac.cn, E-mail: fengx@spaceweather.ac.cn [Space Science Institute, Macau University of Science and Technology, Macao (China)

    2015-10-20

    In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector.

  13. The Flying Spaghetti Monster: Impact of magnetic fields on ram pressure stripping in disk galaxies

    CERN Document Server

    Ruszkowski, M; Lee, D; Shin, M -S

    2012-01-01

    Ram pressure stripping can remove significant amounts of gas from galaxies in clusters, and thus has a large impact on the evolution of cluster galaxies. Recent observations have shown that key properties of ram-pressure stripped tails of galaxies, such as their width and structure, are in conflict with predictions by simulations. To increase the realism of existing simulations, we simulated for the first time a disk galaxy exposed face-on to a uniformly magnetized wind including radiative cooling and self-gravity of the gas. We find that magnetic fields have a strong effect on the morphology of the gas in the tail of the galaxy. While in the purely hydrodynamical case the tail is very clumpy, the MHD case shows very filamentary structures in the tail. The filaments can be strongly supported by magnetic pressure and, wherever this is the case, the magnetic fields vectors tend to be aligned with the filaments. Interestingly, we observe the formation of two dominant magnetized density tails behind the galaxy re...

  14. Estimation of cycle-resolved in-cylinder pressure and air-fuel ratio using spark plug ionization current sensing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.; Guezennec, Y.G.; Rizzoni, G. [Ohio State University, Columbus, OH (United States). Center for Automotive Research and Intelligent Transportation

    2001-10-01

    In recent years, several new sensor technologies have been developed and implemented within automotive industries due to the increasing requirements for improved engine performance and emission reduction. It requires detailed and specified knowledge of the combustion process inside the engine cylinder along with a sophisticated technique in engine diagnostics and control. During the last few years, the ionization current signal detection has been the emerging technology in the new sensor developments, in which the spark plug is used as a combustion probe, to improve the performance and emissions of an automobile engine. In this paper, a novel methodology will be presented which allows the cycle-resolved as well as the meanvalue estimation of the air-fuel ratio and in-cylinder pressure based on the ionization current signal measurements. The implementation details of this methodology as well as extensive results will be presented for a wide range of air-fuel ratios. The main advantage of this new approach to process the ionization signal is its strong potential for real-time estimation of the air-fuel ratio and combustion diagnostics of individual cylinders and engine cycles. All the complex physics during the actual events (combustion process, ion generation, engine dynamics, etc.) are automatically self-extracted by this technique from acquired data in an initial off-line mapping phase. Once this has been performed, the air-fuel ratio and in-cylinder pressure can easily be estimated for each individual cylinder and combustion event in real-time with few computational requirements. Hence, this methodology has a high potential for the real-time combustion diagnostics and engine control based on the air-fuel ratio and in-cylinder pressure, while eliminating the requirements for installing expensive air-fuel ratio and in-cylinder pressure sensors. The results indicate that estimation of the cycle-resolved air-fuel ratio and in-cylinder pressure is reasonably accurate

  15. Numerical investigations on pressurized AL-composite vessel response to hypervelocity impacts: Comparison between experimental works and a numerical code

    Directory of Open Access Journals (Sweden)

    Mespoulet Jérôme

    2015-01-01

    Full Text Available Response of pressurized composite-Al vessels to hypervelocity impact of aluminum spheres have been numerically investigated to evaluate the influence of initial pressure on the vulnerability of these vessels. Investigated tanks are carbon-fiber overwrapped prestressed Al vessels. Explored internal air pressure ranges from 1 bar to 300 bar and impact velocity are around 4400 m/s. Data obtained from experiments (Xray radiographies, particle velocity measurement and post-mortem vessels have been compared to numerical results given from LS-DYNA ALE-Lagrange-SPH full coupling models. Simulations exhibit an under estimation in term of debris cloud evolution and shock wave propagation in pressurized air but main modes of damage/rupture on the vessels given by simulations are coherent with post-mortem recovered vessels from experiments. First results of this numerical work are promising and further simulation investigations with additional experimental data will be done to increase the reliability of the simulation model. The final aim of this crossed work is to numerically explore a wide range of impact conditions (impact angle, projectile weight, impact velocity, initial pressure that cannot be explore experimentally. Those whole results will define a rule of thumbs for the definition of a vulnerability analytical model for a given pressurized vessel.

  16. Numerical investigations on pressurized AL-composite vessel response to hypervelocity impacts: Comparison between experimental works and a numerical code

    Science.gov (United States)

    Mespoulet, Jérôme; Plassard, Fabien; Hereil, Pierre-Louis

    2015-09-01

    Response of pressurized composite-Al vessels to hypervelocity impact of aluminum spheres have been numerically investigated to evaluate the influence of initial pressure on the vulnerability of these vessels. Investigated tanks are carbon-fiber overwrapped prestressed Al vessels. Explored internal air pressure ranges from 1 bar to 300 bar and impact velocity are around 4400 m/s. Data obtained from experiments (Xray radiographies, particle velocity measurement and post-mortem vessels) have been compared to numerical results given from LS-DYNA ALE-Lagrange-SPH full coupling models. Simulations exhibit an under estimation in term of debris cloud evolution and shock wave propagation in pressurized air but main modes of damage/rupture on the vessels given by simulations are coherent with post-mortem recovered vessels from experiments. First results of this numerical work are promising and further simulation investigations with additional experimental data will be done to increase the reliability of the simulation model. The final aim of this crossed work is to numerically explore a wide range of impact conditions (impact angle, projectile weight, impact velocity, initial pressure) that cannot be explore experimentally. Those whole results will define a rule of thumbs for the definition of a vulnerability analytical model for a given pressurized vessel.

  17. Impact of pressure on transport properties of AlGaN/GaN high electron mobility transistor

    Science.gov (United States)

    Wang, Xinbo; Ji, Dong; Lu, Yanwu

    2015-11-01

    The properties of AlxGa1-xN/GaN high electron mobility transistor (HEMT) impacted by pressure are characterized quantitatively. The results indicate that the dislocation density increases as the critical thickness decreases with increasing pressure. The two-dimensional electron gas density was found to be linearly changeable with the pressure. A simulation has been completed to verify the influence of electron mobility. The results show that the misfit dislocation scattering induced by the pressure is a major limiting factor for the properties of HEMT.

  18. An investigation into the clinical impacts of lowering shunt opening pressure in idiopathic normal pressure hydrocephalus: A case series.

    Science.gov (United States)

    Malem, David N; Shand Smith, James D; Toma, Ahmed K; Sethi, Huma; Kitchen, Neil D; Watkins, Laurence D

    2014-08-21

    Introduction. Idiopathic normal pressure hydrocephalus (iNPH) is a shunt- reversible syndrome of the elderly. Shunt management is aimed at achieving a balance between clinical improvement and the complications associated with overdrainage. Although clinical improvement occurs at low pressure, these benefits may be negated by the increase in complication rates observed at lower pressures. The addition of gravity-switch devices has been shown to reduce over drainage problems even at a low valve pressure setting. At our centre the Miethke proGAV is used and commonly lowered below 5 cmH2O to gain further clinical improvement. Object. To determine whether lowering the opening pressure to below 5cmH2O using the proGAV valve in iNPH patients results in a) improved clinical features; and b) no significant increase in complication rates. Methods. A retrospective case series of iNPH patients was undertaken with 24 patients who had the proGAV shunt system inserted with an initial opening pressure of 5cmH2O. Exclusion criteria were secondary NPH, shunt system other than proGAV inserted, no valve adjustment to below 5cmH2O and inadequate follow-up. Outcome measures were clinical improvement (gait, cognition and urinary continence) and complications (subdural haematoma, low-pressure symptoms and valve damage). Results. Patients underwent a total of 29 adjustments to below 5cmH2O. The mean valve opening pressure after the first adjustment was 2.5cmH2O and the mean opening pressure after the second adjustment was 1cmH2O. Overall, outcome after adjustment included 26% no change, 48% improvement and 26% deterioration clinically. One patient (4%) suffered traumatic subdural haematoma that resolved with increasing valve pressure to 20cmH2O. There was no valve damage or low-pressure symptoms after adjustment. Conclusion. This study found that lowering the opening pressure of the proGAV shunt system to below 5cmH2O results in clinical improvement and does not significantly increase the

  19. Impact of salinity on threshold pressure of mudstone in sealing integrity processes of CO2.

    Science.gov (United States)

    Fujii, T.; Sorai, M.

    2015-12-01

    CO2 capture and storage (CCS) technology is a vital tool for deep reduction of CO2 emission from large point sources (e.g., Power generations, Cement and Steel manufacturing plants etc.), and understanding of fate of storing CO2 migration into reservoirs is significantly an important step for CO2 geological storage safety. Several measurements of CO2/water/solid (rock) contact angle related strongly to CO2 migration into pores of rocks have been conducted so far. These findings indicated commonly that water wetting onto mineral surface changes in supercritical CO2 (scCO2) state even though using both pendant and sessile drops and its effect increases as salinity increases, leading to decrease a sealing integrity i.e., threshold pressure of caprock including mudstone and/or shale. However, such mechanisms of scCO2/water/rock interaction are now still being uncleared. Our objective of this study is to investigate an effect of salinity on threshold pressure of natural mudstone, which takes from Kazusa group of Boso peninsula in Japan, in CO2/brine system in order to provide an insight for better understanding of mechanisms of CO2/water (brine)/rock interaction at temperature of 40° and pore pressures of 10 MPa for both CO2 and brine (NaCl), ranging from 0 to 2 molal. Our results demonstrated that threshold pressure value is consist until 0.5 molal NaCl corresponding to density of sea water, but when the salinity exceeds, its value shows a significant drop. It is further indicated that based on comparison results with a modified Young-Laplace eq. using interfacial tension and contact angle values proposed by several researchers, predicted values of threshold pressure increase linearly with increasing salinity and deviate from our experimental data. Thus, model prediction suggests that variation of threshold pressure related to salinity could not be explained fully by changes in interfacial tension and contact angle values with salinity. The present results should

  20. The impact of severity of hypertension on association of PGC-1α Gene with blood pressure and risk of hypertension

    Directory of Open Access Journals (Sweden)

    Wu Yangfeng

    2007-10-01

    Full Text Available Abstract Background Little is known about the impact of severity of hypertension on the association of genes with high blood pressure, which may cause the inconsistently reported associations of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α gene with blood pressure. Methods A cardiovascular epidemiology survey and genotyping were performed in a population-based sample of 1642 apparently healthy residents (648 men and 994 women aged 35–91 years. Results After adjusting for age, sex, body mass index, and antihypertensive medication, G482S and +2962A/G polymorphisms were significantly associated with systolic blood pressures in hypertension patients with medication use (p = 0.023 and 0.022 for G482S and +2962A/G respectively but not in all participants, normotensives, and patients with no medication use. Multivariable logistic models showed that the two polymorphisms were significantly associated with severe hypertension (SBP ≥ 160 mm Hg or DBP ≥ 100 mm Hg regardless of medication use, with an OR of 0.6(95% confidence interval [CI]: 0.4–0.98 for S482S vs. G482G and an OR of 1.9(95% CI: 1.2–3.0 for +2962G/G vs. +2962A/A, but not with regular hypertension (SBP ≥ 140 mm Hg or DBP ≥ 90 mm Hg or current use of antihypertensive medications, with an OR of 0.9(95% CI: 0.7–1.2 for S482S vs. G482G and an OR of 0.9(95% CI: 0.7–1.4 for +2962G/G vs. +2962A/A. Haplotype combination analyses showed a significant synthetic effect (OR of severe hypertension for persons with G482X and +2962G/G = 2.6, 95%CI: 1.5–4.4, with reference to persons with S482S and +2962A/X. Conclusion In this study, we found that G482S and +2962A/G polymorphisms of PGC-1α gene were only significantly associated with severe hypertension defined by occasional clinic blood pressure measurements. This finding suggested severe hypertension rather than regular hypertension should be used as the outcome in studies on association of genes with blood

  1. On the Impact of Particulate Matter Distribution on Pressure Drop of Wall-Flow Particulate Filters

    Directory of Open Access Journals (Sweden)

    Vicente Bermúdez

    2017-03-01

    Full Text Available Wall-flow particulate filters are a required exhaust aftertreatment system to abate particulate matter emissions and meet current and incoming regulations applying worldwide to new generations of diesel and gasoline internal combustion engines. Despite the high filtration efficiency covering the whole range of emitted particle sizes, the porous substrate constitutes a flow restriction especially relevant as particulate matter, both soot and ash, is collected. The dependence of the resulting pressure drop, and hence the fuel consumption penalty, on the particulate matter distribution along the inlet channels is discussed in this paper taking as reference experimental data obtained in water injection tests before the particulate filter. This technique is demonstrated to reduce the particulate filter pressure drop without negative effects on filtration performance. In order to justify these experimental data, the characteristics of the particulate layer are diagnosed applying modeling techniques. Different soot mass distributions along the inlet channels are analyzed combined with porosity change to assess the new properties after water injection. Their influence on the subsequent soot loading process and regeneration is assessed. The results evidence the main mechanisms of the water injection at the filter inlet to reduce pressure drop and boost the interest for control strategies able to force the re-entrainment of most of the particulate matter towards the inlet channels’ end.

  2. Wave-Induced Pressure Under an Internal Solitary Wave and Its Impact at the Bed

    Science.gov (United States)

    Rivera, Gustavo; Diamesis, Peter; Jenkins, James; Berzi, Diego

    2015-11-01

    The bottom boundary layer (BBL) under a mode-1 internal solitary wave (ISW) of depression propagating against an oncoming model barotropic current is examined using 2-D direct numerical simulation based on a spectral multidomain penalty method model. Particular emphasis is placed on the diffusion into the bed of the pressure field driven by the wake and any near-bed instabilities produced under specific conditions. To this end, a spectral nodal Galerkin approach is used for solving the diffusion equation for the wave-induced pressure. At sufficiently high ISW amplitude, the BBL undergoes a global instability which produces intermittent vortex shedding from within the separation bubble in the lee of the wave. The interplay between the bottom shear stress field and pressure perturbations during vortex ejection events and the subsequent evolution of the vortices is examined. The potential for bed failure upon the passage of the ISW trough and implications for resuspension of bottom particulate matter are both discussed in the context of specific sediment transport models.

  3. The impact of sea surface currents in wave power potential modeling

    Science.gov (United States)

    Zodiatis, George; Galanis, George; Kallos, George; Nikolaidis, Andreas; Kalogeri, Christina; Liakatas, Aristotelis; Stylianou, Stavros

    2015-11-01

    The impact of sea surface currents to the estimation and modeling of wave energy potential over an area of increased economic interest, the Eastern Mediterranean Sea, is investigated in this work. High-resolution atmospheric, wave, and circulation models, the latter downscaled from the regional Mediterranean Forecasting System (MFS) of the Copernicus marine service (former MyOcean regional MFS system), are utilized towards this goal. The modeled data are analyzed by means of a variety of statistical tools measuring the potential changes not only in the main wave characteristics, but also in the general distribution of the wave energy and the wave parameters that mainly affect it, when using sea surface currents as a forcing to the wave models. The obtained results prove that the impact of the sea surface currents is quite significant in wave energy-related modeling, as well as temporally and spatially dependent. These facts are revealing the necessity of the utilization of the sea surface currents characteristics in renewable energy studies in conjunction with their meteo-ocean forecasting counterparts.

  4. Mechanical impacts of poloidal eddy currents on the continuous vacuum vessel of a tokamak

    Energy Technology Data Exchange (ETDEWEB)

    In, Sang Ryul; Yoon, Byung Joo

    1996-11-01

    Poloidal eddy currents are induced on the continuous torus vacuum vessel by changes of the toroidal field during the machine start-up (toroidal field coil charge), shut-down (toroidal field coil discharge) and plasma disruption (plasma diamagnetism change). Analytic forms for the eddy currents flowing on the vessel, consequent pressures and forces acting on it are presented in this report. The results are applied to typical operation modes of the KT-2 tokamak. Stress analysis for two typical operation modes of toroidal field damping during a machine shut-gown and plasma energy quench during a plasma disruption were carried out using 3D FEM code (ANSYS 5.2). (author). 5 tabs., 22 figs., 9 refs.

  5. Air-sea Energy Transfer at Mesoscale in a Coupled High-resolution Model: Impact of Resolution and Current Feedback

    Science.gov (United States)

    Jullien, S.; Colas, F.; Masson, S. G.; Oerder, V.; Echevin, V.; Samson, G.; Crétat, J.; Berthet, S.; Hourdin, C.

    2015-12-01

    Winds are usually considered to force the ocean but recent studies suggested that oceanic mesoscale activity, characterized by eddies, filaments and fronts, could also affect the wind field. These structures feature abrupt changes in sea surface temperature (SST), surface pressure and surface currents that could impact the atmosphere by enhancing/reducing air-sea fluxes, accelerating/decelerating winds, modifying the wind-pressure balance… At this time, the detailed processes associated to such coupling, its intensity and significance remain a matter of research. Here, a state-of-the-art WRF-OASIS-NEMO coupled model is set up over a wide tropical channel (45°S-45°N) at various resolutions: 3/4°, 1/4° and 1/12° in both the ocean and the atmosphere. Several experiments are conducted in forced, partially or fully coupled modes, to highlight the effect of resolution and the role of SST vs. current feedback to energy injection into the ocean and the atmosphere. In strong mesoscale activity regions, a negative wind power input from the atmosphere to the ocean is seen at scales ranging from 100km to more than 1000km. Nonexistent at 3/4°, this negative forcing, acting against oceanic mesoscale activity, is almost twice more important at 1/12° than at 1/4°. In addition, partially coupled simulations, i.e. without current feedback, show that the impact of thermal coupling on this process is very limited. Energy injection to the marine atmospheric boundary layer also features imprints from oceanic mesoscale. Energy injection by scales shorter than 300km represents up to 20% of the total. Finally we show that increasing oceanic resolution, and therefore mesoscale activity, is necessary to resolve the full wind stress spectrum and has an upscaling effect by enhancing atmospheric mesoscale, which is larger scale than in the ocean. Using 1/4°oceanic resolution instead of 1/12° leads to a 50% loss of energy in the atmospheric mesoscale.

  6. Current impact and future directions of high throughput sequencing in plant virus diagnostics.

    Science.gov (United States)

    Massart, Sebastien; Olmos, Antonio; Jijakli, Haissam; Candresse, Thierry

    2014-08-08

    The ability to provide a fast, inexpensive and reliable diagnostic for any given viral infection is a key parameter in efforts to fight and control these ubiquitous pathogens. The recent developments of high-throughput sequencing (also called Next Generation Sequencing - NGS) technologies and bioinformatics have drastically changed the research on viral pathogens. It is now raising a growing interest for virus diagnostics. This review provides a snapshot vision on the current use and impact of high throughput sequencing approaches in plant virus characterization. More specifically, this review highlights the potential of these new technologies and their interplay with current protocols in the future of molecular diagnostic of plant viruses. The current limitations that will need to be addressed for a wider adoption of high-throughput sequencing in plant virus diagnostics are thoroughly discussed.

  7. Characterization of a Setup to test the Impact of High-Amplitude Pressure Waves on Living Cells

    Science.gov (United States)

    Schmidt, Mischa; Kahlert, Ulf; Wessolleck, Johanna; Maciaczyk, Donata; Merkt, Benjamin; Maciaczyk, Jaroslaw; Osterholz, Jens; Nikkhah, Guido; Steinhauser, Martin O.

    2014-01-01

    The impact of pressure waves on cells may provide several possible applications in biology and medicine including the direct killing of tumors, drug delivery or gene transfection. In this study we characterize the physical properties of mechanical pressure waves generated by a nanosecond laser pulse in a setup with well-defined cell culture conditions. To systematically characterize the system on the relevant length and time scales (micrometers and nanoseconds) we use photon Doppler velocimetry (PDV) and obtain velocity profiles of the cell culture vessel at the passage of the pressure wave. These profiles serve as input for numerical pressure wave simulations that help to further quantify the pressure conditions on the cellular length scale. On the biological level we demonstrate killing of glioblastoma cells and quantify experimentally the pressure threshold for cell destruction. PMID:24458018

  8. Bubble snap-off and capillary-back pressure during counter-current spontaneous imbibition into model pores.

    Science.gov (United States)

    Unsal, Evren; Mason, Geoffrey; Morrow, Norman R; Ruth, Douglas W

    2009-04-09

    A previous paper (Unsal, E.; Mason, G.; Ruth, D. W.; Morrow, N. R. J. Colloid Interface Sci. 2007, 315, 200-209) reported experiments involving counter-current spontaneous imbibition into a model pore system consisting of a rod in an angled slot covered by a glass plate. Such an arrangement gives two tubes with different cross-sections (both size and shape) with an interconnection through the gap between the rod and the plate. In the previous experiments, the wetting phase advanced in the small tube and nonwetting phase retreated in the large tube. No bubbles were formed. In this paper, we study experimentally and theoretically the formation of bubbles at the open end of the large tube and their subsequent snap-off. Such bubbles reduce the capillary back pressure produced by the larger tube and can thus have an effect on the local rate of imbibition. In the model pore system, the rod was either in contact with the glass, forming two independent tubes, or the rod was spaced from the glass to allow cross-flow between the tubes. For small gaps, there were three distinct menisci. The one with the highest curvature was between the rod and the plate. The next most highly curved was in the smaller tube, and the least highly curved meniscus was in the large tube and this was the tube from which the bubbles developed. The pressure in the dead end of the system was recorded during imbibition. Once the bubble starts to form outside of the tube, the pressure drops rapidly and then steadies. After the bubble snaps off, the pressure rises to almost the initial value and stays essentially constant until the next bubble starts to form. After snap-off, the meniscus in the large tube appears to invade the large tube for some distance. The snap-off is the result of capillary instability; it takes place significantly inside the large tube with flow of wetting phase moving in the angular corners. As imbibition into the small tube progresses, the rate of imbibition decreases and the

  9. Impact of currents on surface flux computations and their feedback on dynamics at regional scales

    Science.gov (United States)

    Olita, A.; Iermano, I.; Fazioli, L.; Ribotti, A.; Tedesco, C.; Pessini, F.; Sorgente, R.

    2015-08-01

    A twin numerical experiment was conducted in the seas around the island of Sardinia (Western Mediterranean) to assess the impact, at regional and coastal scales, of the use of relative winds (i.e., taking into account ocean surface currents) in the computation of heat and momentum fluxes through standard (Fairall et al., 2003) bulk formulas. The Regional Ocean Modelling System (ROMS) was implemented at 3 km resolution in order to well resolve mesoscale processes, which are known to have a large influence in the dynamics of the area. Small changes (few percent points) in terms of spatially averaged fluxes correspond to quite large differences of such quantities (about 15 %) in spatial terms and in terms of kinetics (more than 20 %). As a consequence, wind power input P is also reduced by ~ 14 % on average. Quantitative validation with satellite SST suggests that such a modification of the fluxes improves the model solution especially in the western side of the domain, where mesoscale activity (as suggested by eddy kinetic energy) is stronger. Surface currents change both in their stable and fluctuating part. In particular, the path and intensity of the Algerian Current and of the Western Sardinia Current (WSC) are impacted by the modification in fluxes. Both total and eddy kinetic energies of the surface current field are reduced in the experiment where fluxes took into account the surface currents. The main dynamical correction is observed in the SW area, where the different location and strength of the eddies influence the path and intensity of the WSC. Our results suggest that, even at local scales and in temperate regions, it would be preferable to take into account such a contribution in flux computations. The modification of the original code, substantially cost-less in terms of numerical computation, improves the model response in terms of surface fluxes (SST validated) and it also likely improves the dynamics as suggested by qualitative comparison with

  10. Impact of currents on surface fluxes computation and their feedback on coastal dynamics

    Directory of Open Access Journals (Sweden)

    A. Olita

    2015-01-01

    Full Text Available A twin numerical experiment was conducted in the seas of Sardinia (Western Mediterranean to assess the impact, at coastal scales, of the use of relative winds (i.e. taking into account ocean surface currents in the computation of heat and momentum fluxes through bulk formulas. The model, the Regional Ocean Modeling System (ROMS, was implemented at 2 km of resolution in order to well resolve (sub-mesoscale dynamics. Small changes (1–2% in terms of spatially-averaged fluxes correspond to quite large spatial differences of such quantities (up to 15–20% and to comparably significant differences in terms of mean velocities of the surface currents. Wind power input of the wind stress to the ocean surface P results also reduced by a 15%, especially where surface currents are stronger. Quantitative validation with satellite SST suggests that such a modification on the fluxes improves the model solution especially in areas of cyclonic circulation, where the heat fluxes correction is predominant in respect to the dynamical correction. Surface currents changes above all in their fluctuating part, while the stable part of the flow show changes mainly in magnitude and less in its path. Both total and eddy kinetic energies of the surface current field results reduced in the experiment where fluxes took into account for surface currents. Dynamically, the largest correction is observed in the SW area where anticyclonic eddies approach the continental slope. This reduction also impacts the vertical dynamics and specifically the local upwelling that results diminished both in spatial extension as well in magnitude. Simulations suggest that, even at local scales and in temperate regions, it is preferable to take into account for such a component in fluxes computation. Results also confirm the tight relationship between local coastal upwelling and eddy-slope interactions in the area.

  11. Systematic review of current efforts to quantify the impacts of climate change on undernutrition.

    Science.gov (United States)

    Phalkey, Revati K; Aranda-Jan, Clara; Marx, Sabrina; Höfle, Bernhard; Sauerborn, Rainer

    2015-08-18

    Malnutrition is a challenge to the health and productivity of populations and is viewed as one of the five largest adverse health impacts of climate change. Nonetheless, systematic evidence quantifying these impacts is currently limited. Our aim was to assess the scientific evidence base for the impact of climate change on childhood undernutrition (particularly stunting) in subsistence farmers in low- and middle-income countries. A systematic review was conducted to identify peer-reviewed and gray full-text documents in English with no limits for year of publication or study design. Fifteen manuscripts were reviewed. Few studies use primary data to investigate the proportion of stunting that can be attributed to climate/weather variability. Although scattered and limited, current evidence suggests a significant but variable link between weather variables, e.g., rainfall, extreme weather events (floods/droughts), seasonality, and temperature, and childhood stunting at the household level (12 of 15 studies, 80%). In addition, we note that agricultural, socioeconomic, and demographic factors at the household and individual levels also play substantial roles in mediating the nutritional impacts. Comparable interdisciplinary studies based on primary data at a household level are urgently required to guide effective adaptation, particularly for rural subsistence farmers. Systemization of data collection at the global level is indispensable and urgent. We need to assimilate data from long-term, high-quality agricultural, environmental, socioeconomic, health, and demographic surveillance systems and develop robust statistical methods to establish and validate causal links, quantify impacts, and make reliable predictions that can guide evidence-based health interventions in the future.

  12. Pressure changes in spinal canal and evaluation of spinal cord injuries in spinal section subjected to impact

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To observe pressure changes in the spinal canal of the vertebrarium subjected to impact. From the point of view of impact, pressure changes and spinal cord injuries, the relationship between the type of spinal fracture and the severity of spinal cord injuries were analyzed and some experimental data were provided for early evaluation of severity of spinal cord injuries.   Methods: An experimental model of spinal burst fracture was made with Type BIM-I bio-impact machine and techniques of high velocity vertical loading in static pattern and stress shielding were adopted. Vertebral sections T10-L4 taken from fresh cadavers were impacted and pressure changes in the spinal canal were observed. The types and severity of spinal fracture were studied with gross and radiography examination.   Results: Great positive pressure wave (wave A) in the spinal canal of the 4 vertebral specimens with burst fracture was recorded. The peak value of pressure was correlated with the severity of posterior column injuries. Generally, the peak value of pressure was low in the samples with posterior column injuries, but high in the samples without injuries. The predominant features of fractures were burst fractures of vertebral body and severe destruction of the skeletal and fiber structure of the spinal canal. Positive and negative pressure waves (wave B) were recorded in 2 vertebral samples in which no significant abnormal changes were found by radiography examination, however, a little liquid effusion in the vertebral body was found by gross examination.   Conclusions: The type of pressure wave in the spinal canal is related to the deformation or the destruction of the spinal canal structure. The peak value of the pressure is non-linearly related to the obstruction in the spinal canal, but related to posterior column injuries.

  13. Impact Pressure of Incident Regular Waves and Irregular Waves on the Subface of Open-Piled Structures

    Institute of Scientific and Technical Information of China (English)

    任冰; 王永学

    2004-01-01

    This paper presents the results of comparison of impact pressures on open-plied structures induced by regular waves and irregular waves in a laboratory channel. Regular waves with wave heights ranging from 0.1 ~ 0.2 m and periods ranging from 1.0 ~ 2.0 s are tested. The target spectrm for the irregular wave is JONSWAP spectrum. Irregular waves with significant wave heights in the range of 0.10 ~ 0.25 m and peak periods in the range of 1.0 ~ 2.0 s are tested. The relative clearance s/H1/3(H) is between - 0.1 and 0.4, s being the subface level of structure model above the still water level. Time series of impact pressure are analyzed to indicate whether the property of impact pressures induced by the regular wave significantly deviates from that by the irregular wave. The distribution of the impact pressure along the underside of the structure is compared for different types of incident waves. The effects of wave parameters, structure dimension and structure clearance on the impact pressure are also discussed.

  14. How will the growing threat of resistant hypertension impact the future treatment of high blood pressure?

    Science.gov (United States)

    Lackland, Daniel T

    2013-11-01

    Hypertension treatment and control efforts represent a major component of primary care with dedicated clinical guidelines and recommendations. However, high blood pressure (BP) control rates are complicated with the difficult to treat and resistant hypertensive patients. This category of patient, therefore, affects the development and implementation of the clinical guidelines. The recommendations of specific algorithms for resistant hypertension and difficult-to-treat patients with elevated BPs have been developed in consideration of new therapies and combination drug treatment. Hypertension treatment guidelines include and will continue to grade evidence from randomized clinical trials with detailed strategies on the management of these high-risk patients. Although resistant hypertension affects high BP control rates, the inclusion of refined pharmaceutical and device treatment strategies in evidence-based guidelines will be expected to have a significant impact on the clinical management of this high-risk patient population.

  15. A regularized model for impact in explicit dynamics applied to the split Hopkinson pressure bar

    Science.gov (United States)

    Otto, Peter; De Lorenzis, Laura; Unger, Jörg F.

    2016-10-01

    In the numerical simulation of impact phenomena, artificial oscillations can occur due to an instantaneous change of velocity in the contact area. In this paper, a nonlinear penalty regularization is used to avoid these oscillations. A particular focus is the investigation of higher order methods in space and time to increase the computational efficiency. The spatial discretization is realized by higher order spectral element methods that are characterized by a diagonal mass matrix. The time integration scheme is based on half-explicit Runge-Kutta scheme of fourth order. For the conditionally stable scheme, the critical time step is influenced by the penalty regularization. A framework is presented to adjust the penalty stiffness and the time step for a specific mesh to avoid oscillations. The methods presented in this paper are applied to 1D-simulations of a split Hopkinson pressure bar, which is commonly used for the investigation of materials under dynamic loading.

  16. Characterization of direct-current atmospheric-pressure discharges useful for ambient desorption/ionization mass spectrometry.

    Science.gov (United States)

    Shelley, Jacob T; Wiley, Joshua S; Chan, George C Y; Schilling, Gregory D; Ray, Steven J; Hieftje, Gary M

    2009-05-01

    Two relatively new ambient ionization sources, direct analysis in real time (DART) and the flowing atmospheric-pressure afterglow (FAPA), use direct current, atmospheric-pressure discharges to produce reagent ions for the direct ionization of a sample. Although at a first glance these two sources appear similar, a fundamental study reveals otherwise. Specifically, DART was found to operate with a corona-to-glow transition (C-G) discharge whereas the FAPA was found to operate with a glow-to-arc transition (G-A) discharge. The characteristics of both discharges were evaluated on the basis of four factors: reagent-ion production, response to a model analyte (ferrocene), infrared (IR) thermography of the gas used for desorption and ionization, and spatial emission characteristics. The G-A discharge produced a greater abundance and a wider variety of reagent ions than the C-G discharge. In addition, the discharges yielded different adducts and signal strengths for ferrocene. It was also found that the gas exiting the discharge chamber reached a maximum of 235 degrees C and 55 degrees C for the G-A and C-G discharges, respectively. Finally, spatially resolved emission maps of both discharges showed clear differences for N(2)(+) and O(I). These findings demonstrate that the discharges used by FAPA and DART are fundamentally different and should have different optimal applications for ambient desorption/ionization mass spectrometry (ADI-MS).

  17. [Population characteristics and impact on heart rate variability, heart rate and blood pressure of passive smoking].

    Science.gov (United States)

    Zhao, Jing; He, Fei; Hu, Da-yi; Ding, Rong-jing; Yu, Xiao-jun; Wang, Long; Zhang, Ping; Li, Xue-bin; Guo, Ji-hong; Liu, Wen-ling; Li, Cui-lan; Li, Lei; Gao, Chuan-yu; Zhao, Luo-sha; Chu, Ying-jie; Huang, Zhen-wen; Wei, Jing-han; Hua, Shao-hua; Liu, Rui-yun; Zhuang, Xiao-feng

    2013-05-01

    To investigate the basic characteristics of passive smoking population, and the impact of passive smoking on heart rate variability, heart rate and blood pressure. Eighty-six passive smokers [mean age: (52.4 ± 7.6) years] were recruited from patients and their relatives who visited cardiovascular outpatient department and excluded structural heart disease between June 2010 and June 2012, 80 normal subjects who were not exposed to smoking served as controls. Questionnaire survey, 24 hours ambulatory electrocardiogram examination and blood pressure measurement were performed in all recruited subjects. (1) Non-marriage rate [18.60% (16/86) vs. 3.75% (3/80), P professional technology industry employers [20.93% (18/86) vs. 36.25% (29/80), P restaurants (48.84%, 42/86). (2) Standard of the normal sinus RR intervals (SDNN), the normal consecutive sinus RR interval difference between the root-mean-square (rMSSD) and adjacent the difference between the RR interval>50 ms the number of share the percentage (PNN50) were significantly lower in passive smoking group than in the control group (all P 0.05). Ultra-low-frequency power (VLF), low frequency power (LF), high frequency power (HF) and LF/HF were significantly lower in passive smoking group than in the control group (all P 0.05). Marriage status, education level, profession and daily working time are independent determinants for passive smoking. Passive smoking mainly occurred in the workplace, entertainment venues and restaurants. Passive smoking is linked with reduced heart rate variability, increased 24 h average heart rate and diastolic blood pressure.

  18. The Impact of opium consumption on blood glucose, serum lipids and blood pressure, and related mechanisms

    Directory of Open Access Journals (Sweden)

    Hamid Najafipour

    2016-10-01

    Full Text Available AbstractAim: Substance abuse has become a universal crisisin our modern age. Among illegal substances, opium and its derivatives have been ranked second in terms of usage after cannabis in the world. In many Asian regions, the use of opium enjoys a high social acceptance; hence, some common people and even medical practitioners believe that opium lowers blood glucose and pressure and treat dyslipidemia. How much this belief is scientifically justified? Method: The results of available studies on both humans and animals searched in different search engines up to mid-2016 were integrated (77 articles. Upon the findings we try to offer a more transparent picture of the effects of opium on the mentioned factors along with the probable underlying mechanisms of its action. Results: Taken together, a variety of evidences suggest that the consumption of opium has no scientific justification for amendment of these biochemical variables. The mechanisms proposed so far for the action of opium in the three above disorders are summarized at the end of the article. Short term effects seems to be mostly mediated through central nervous system (neural and hormonal mechanisms, but long term effects are often due to the structural and functional alterations in some body organs. Conclusion: Although opium may temporarily reduce blood pressure, but it increases blood glucose and most of blood lipids. Moreover its long term use has negative impacts and thus it aggravates diabetes, dyslipidemia and hypertension. Accordingly, it is necessary to inform societies about the potential disadvantages of unauthorized opium consumption.

  19. Current and Future Impact Risks from Small Debris to Operational Satellites

    Science.gov (United States)

    Liou, Jer-Chyi; Kessler, Don

    2011-01-01

    The collision between Iridium 33 and Cosmos 2251 in 2009 signaled the potential onset of the collision cascade effect, commonly known as the "Kessler Syndrome", in the low Earth orbit (LEO) region. Recent numerical simulations have shown that the 10 cm and larger debris population in LEO will continue to increase even with a good implementation of the commonly-adopted mitigation measures. This increase is driven by collisions involving large and massive intacts, i.e., rocket bodies and spacecraft. Therefore, active debris removal (ADR) of large and massive intacts with high collision probabilities has been argued as a direct and effective means to remediate the environment in LEO. The major risk for operational satellites in the environment, however, comes from impacts with debris just above the threshold of the protection shields. In general, these are debris in the millimeter to centimeter size regime. Although impacts by these objects are insufficient to lead to catastrophic breakup of the entire vehicle, the damage is certainly severe enough to cause critical failure of the key instruments or the entire payload. The focus of this paper is to estimate the impact risks from 5 mm and 1 cm debris to active payloads in LEO (1) in the current environment and (2) in the future environment based on different projection scenarios, including ADR. The goal of the study is to quantify the benefits of ADR in reducing debris impact risks to operational satellites.

  20. Combined impact of lead, cadmium, polychlorinated biphenyls and non-chemical risk factors on blood pressure in NHANES

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Junenette L., E-mail: petersj@bu.edu; Patricia Fabian, M., E-mail: pfabian@bu.edu; Levy, Jonathan I., E-mail: jonlevy@bu.edu

    2014-07-15

    High blood pressure is associated with exposure to multiple chemical and non-chemical risk factors, but epidemiological analyses to date have not assessed the combined effects of both chemical and non-chemical stressors on human populations in the context of cumulative risk assessment. We developed a novel modeling approach to evaluate the combined impact of lead, cadmium, polychlorinated biphenyls (PCBs), and multiple non-chemical risk factors on four blood pressure measures using data for adults aged ≥20 years from the National Health and Nutrition Examination Survey (1999–2008). We developed predictive models for chemical and other stressors. Structural equation models were applied to account for complex associations among predictors of stressors as well as blood pressure. Models showed that blood lead, serum PCBs, and established non-chemical stressors were significantly associated with blood pressure. Lead was the chemical stressor most predictive of diastolic blood pressure and mean arterial pressure, while PCBs had a greater influence on systolic blood pressure and pulse pressure, and blood cadmium was not a significant predictor of blood pressure. The simultaneously fit exposure models explained 34%, 43% and 52% of the variance for lead, cadmium and PCBs, respectively. The structural equation models were developed using predictors available from public data streams (e.g., U.S. Census), which would allow the models to be applied to any U.S. population exposed to these multiple stressors in order to identify high risk subpopulations, direct intervention strategies, and inform public policy. - Highlights: • We evaluated joint impact of chemical and non-chemical stressors on blood pressure. • We built predictive models for lead, cadmium and polychlorinated biphenyls (PCBs). • Our approach allows joint evaluation of predictors from population-specific data. • Lead, PCBs and established non-chemical stressors were related to blood pressure.

  1. A Comparison of Measured and Predicted Wave-Impact Pressures from Breaking and Non-breaking Waves

    CERN Document Server

    Fullerton, Anne M; Brewton, Susan; Brucker, Kyle A; O'Shea, Thomas T; Dommermuth, Douglas G

    2014-01-01

    Impact loads from waves on vessels and coastal structures are complex and may involve wave breaking, which has made these loads difficult to estimate numerically or empirically. Results from previous experiments have shown a wide range of forces and pressures measured from breaking and nonbreaking waves, with no clear trend between wave characteristics and the localized forces and pressures that they generate. In 2008, a canonical breaking wave impact data set was obtained at the Naval Surface Warfare Center, Carderock Division, by measuring the distribution of impact pressures of incident nonbreaking and breaking waves on one face of a cube. This experimental effort was sponsored by the Office of Naval Research (ONR), under the Dynamics of Interacting Platforms Program, Program Manager Dr. Ron Joslin. The effects of wave height, wavelength, face orientation, face angle, and submergence depth were investigated. Additionally, a limited number of runs were made at low forward speeds, ranging from about 0.5 to 2...

  2. Impacts of the current economic crisis on Southeast Asian labour markets

    Directory of Open Access Journals (Sweden)

    John Walsh

    2010-10-01

    Full Text Available The current economic crisis has caused most of the western world to fall into recession because of the credit crunch and the collapse of much of the under-regulated and over-confident banking industry. However, in most of Asia, especially developing Asia, the crisis has affected manufacturing and, hence, employment rather than the finance sectors, especially because the latter had already been restructured following the 1997 Asian Crisis. This paper considers the impact of the crisis on the range of labour markets across the region and assesses the ongoing relevance of the development model that is posited on low labour cost manufacturing aimed at assisting export industries. Impacts considered include migration flows of labour, the possibility of augmenting added value to existing production and the need to upgrade skills and competencies.

  3. Environmental Impacts on Spiking Properties in Hodgkin-Huxley Neuron with Direct Current Stimulus

    Institute of Scientific and Technical Information of China (English)

    YUAN Chang-Qing; ZHAO Tong-Jun; ZHAN Yong; ZHANG Su-Hua; LIU Hui; ZHANG Yu-Hong

    2009-01-01

    Based on the well accepted Hodgkin-Huxley neuron model, the neuronal intrinsic excitability is studied when the neuron is subject to varying environmental temperatures, the typical impact for its regulating ways. With computer simulation, it is found that altering environmental temperature can improve or inhibit the neuronal intrinsic excitability so as to influence the neuronal spiking properties. The impacts from environmental factors can be understood that ,the neuronal spiking threshold is essentially influenced by the fluctuations in the environ-ment. With the environmental temperature varying, burst spiking is realized for the neuronal membrane voltage because of the environment-dependent spiking threshold. This burst induced by changes in spiking threshold is different from that excited by input currents or other stimulus.

  4. Effects of Microstructural Inhomogeneity on Charpy Impact Properties for Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seokmin; Song, Jaemin; Kim, Min-Chul; Choi, Kwon-Jae; Lee, Bong-Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Reactor pressure vessel (RPV) steels are fabricated by vacuum carbon deoxidation (VCD), and then heat treatment of quenching and tempering is conducted after forging. The through-the-thickness variation of microstructure in RPV can occur due to the cooling rate gradient during quenching and inhomogeneous deformation during forging process. The variation of microstructure in RPV affects the mechanical properties, and inhomogeneity in mechanical properties can occur. The evaluation of mechanical properties of RPV is conducted at thickness of 1/4T. In order to evaluate the safety of RPV more correctly, the research about the through-the-thickness variation of microstructure and mechanical properties in RPV is need. 1. The fine low bainite (LB) is the dominant phase at the inner-surface (0T), but coarse upper bainite (UB) is the dominant phase at the center (1/2T). This is because cooling rate gradient from surface to center occurs during quenching. 2. Inter-lath carbides act as fracture initiation site, and it reduces impact toughness. 3. The upper shelf energy is low and the reference temperatures are high at the 1/4T. Impact properties are poor at 1/4T because of the formation of coarse upper bainite structure and coarse inter-lath carbides.

  5. The current situation of impact of coal mine developing on environment in China and government proposal

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yang [China University of Mining and Technology, Beijing (China). Ministry of Land and Resources

    2005-07-01

    Current environmental problems caused by coal mining in China, the importance of management of the environment, impact of coal mining on land and water resources, and upcoming coal development are discussed. It is suggested that the government should act in two ways: take responsibility for management of reclamation of mines existing before 1986, and set up mechanisms to protect the environment, starting with the publishing of relevant laws and regulations. Methods for solving environmental issues include: prepare a practical plan, establish an environmental control fund, establish a special fund to protect the environment, and develop new ways to combine protection of the biological environment and land reclamation. 5 refs., 3 tabs.

  6. Impact and Limitations Deriving from Basel II within the Context of the Current Financial Crisis

    Directory of Open Access Journals (Sweden)

    Oana Miruna DĂNILĂ

    2012-06-01

    Full Text Available The Banking sector risk management framework, geared towards maintaining a solid capital adequacy level, has witnessed a permanent evolution, determined by the global economic and financial reality.Basel II has brought an improvement of the risk management framework by adding minimum capital levels corresponding to market and operational risk and by the introduction of internal rating models. However the current crisis has brought forward some adverse effects as well as limitations.This paper analyses the evolution of prudential rules and regulations introduced by Basel II and their impact on the banking system together with outlining certain limitations.

  7. Impact of Atrial Fibrillation Ablation on Left Ventricular Filling Pressure and Left Atrial Remodeling

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Simone Nascimento dos, E-mail: simonens@cardiol.br [Instituto Brasília de Arritmia- Universidade de Brasília, DF (Brazil); Faculdade de Medicina (UnB), Brasília, DF (Brazil); Henz, Benhur Davi; Zanatta, André Rodrigues; Barreto, José Roberto; Loureiro, Kelly Bianca; Novakoski, Clarissa; Santos, Marcus Vinícius Nascimento dos; Giuseppin, Fabio F.; Oliveira, Edna Maria; Leite, Luiz Roberto [Instituto Brasília de Arritmia- Universidade de Brasília, DF (Brazil)

    2014-12-15

    Left ventricular (LV) diastolic dysfunction is associated with new-onset atrial fibrillation (AF), and the estimation of elevated LV filling pressures by E/e' ratio is related to worse outcomes in patients with AF. However, it is unknown if restoring sinus rhythm reverses this process. To evaluate the impact of AF ablation on estimated LV filling pressure. A total of 141 patients underwent radiofrequency (RF) ablation to treat drug-refractory AF. Transthoracic echocardiography was performed 30 days before and 12 months after ablation. LV functional parameters, left atrial volume index (LAVind), and transmitral pulsed and mitral annulus tissue Doppler (e' and E/e') were assessed. Paroxysmal AF was present in 18 patients, persistent AF was present in 102 patients, and long-standing persistent AF in 21 patients. Follow-up included electrocardiographic examination and 24-h Holter monitoring at 3, 6, and 12 months after ablation. One hundred seventeen patients (82.9%) were free of AF during the follow-up (average, 18 ± 5 months). LAVind reduced in the successful group (30.2 mL/m{sup 2} ± 10.6 mL/m{sup 2} to 22.6 mL/m{sup 2} ± 1.1 mL/m{sup 2}, p < 0.001) compared to the non-successful group (37.7 mL/m{sup 2} ± 14.3 mL/m{sup 2} to 37.5 mL/m{sup 2} ± 14.5 mL/m{sup 2}, p = ns). Improvement of LV filling pressure assessed by a reduction in the E/e' ratio was observed only after successful ablation (11.5 ± 4.5 vs. 7.1 ± 3.7, p < 0.001) but not in patients with recurrent AF (12.7 ± 4.4 vs. 12 ± 3.3, p = ns). The success rate was lower in the long-standing persistent AF patient group (57% vs. 87%, p = 0.001). Successful AF ablation is associated with LA reverse remodeling and an improvement in LV filling pressure.

  8. Impact of Atrial Fibrillation Ablation on Left Ventricular Filling Pressure and Left Atrial Remodeling

    Directory of Open Access Journals (Sweden)

    Simone Nascimento dos Santos

    2014-12-01

    Full Text Available Background: Left ventricular (LV diastolic dysfunction is associated with new-onset atrial fibrillation (AF, and the estimation of elevated LV filling pressures by E/e' ratio is related to worse outcomes in patients with AF. However, it is unknown if restoring sinus rhythm reverses this process. Objective: To evaluate the impact of AF ablation on estimated LV filling pressure. Methods: A total of 141 patients underwent radiofrequency (RF ablation to treat drug-refractory AF. Transthoracic echocardiography was performed 30 days before and 12 months after ablation. LV functional parameters, left atrial volume index (LAVind, and transmitral pulsed and mitral annulus tissue Doppler (e' and E/e' were assessed. Paroxysmal AF was present in 18 patients, persistent AF was present in 102 patients, and long-standing persistent AF in 21 patients. Follow-up included electrocardiographic examination and 24-h Holter monitoring at 3, 6, and 12 months after ablation. Results: One hundred seventeen patients (82.9% were free of AF during the follow-up (average, 18 ± 5 months. LAVind reduced in the successful group (30.2 mL/m2 ± 10.6 mL/m2 to 22.6 mL/m2 ± 1.1 mL/m2, p < 0.001 compared to the non-successful group (37.7 mL/m2 ± 14.3 mL/m2 to 37.5 mL/m2 ± 14.5 mL/m2, p = ns. Improvement of LV filling pressure assessed by a reduction in the E/e' ratio was observed only after successful ablation (11.5 ± 4.5 vs. 7.1 ± 3.7, p < 0.001 but not in patients with recurrent AF (12.7 ± 4.4 vs. 12 ± 3.3, p = ns. The success rate was lower in the long-standing persistent AF patient group (57% vs. 87%, p = 0.001. Conclusion: Successful AF ablation is associated with LA reverse remodeling and an improvement in LV filling pressure.

  9. Assessment of the impact of HTSCs on superconducting fault-current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Giese, R.F. [Argonne National Lab., IL (United States); Runde, M. [Energiforsyningens Forskningsinstitutt A/S, Trondheim (Norway)

    1993-03-01

    The possible impact of nitrogen-cooled superconductors on the desip and cost of superconducting fault-current limiters is assessed by considering the technical specifications such devices must meet and by comparing material properties of 77-K and 4-K superconductors. The main advantages of operating superconductors at 77 K are that the refrigeration operating cost is reduced by a factor of up to 25 and the refrigeration capital cost is reduced by a factor of up to 10. The heat capacity is several orders of magnitude Larger at 77 K and at 4 K. This phenomenon increases conductor stability against flux jumps but makes switching from the superconducting to the normal state slow and difficult. Therefore, a high critical current density, probably at least 10{sup 5} A/cm{sup 2}, is required.

  10. The Camino intracranial pressure sensor: is it optimal technology? An internal audit with a review of current intracranial pressure monitoring technologies.

    Science.gov (United States)

    Piper, I; Barnes, A; Smith, D; Dunn, L

    2001-11-01

    To audit the reliability of the Camino intracranial pressure (ICP) sensor (Camino Laboratories, San Diego, CA) in our clinical practice as part of a continuing quality assurance program, and to assess its relative usefulness as compared with currently available ICP monitoring technologies that we reviewed. Prospective audit of ICP device reliability and function in 50 patients with head injuries. Zero drift was recorded immediately after the ICP device was removed from the patient. Dynamic frequency response bench testing of each functioning catheter from 0 to 30 Hz and static calibration testing from 0 to 100 mmHg during environmental temperature variation from 22 to 40 degrees C were carried out. Zero drift (range, -13 to 22 mmHg; median, -1 mmHg) was recorded immediately after the devices were removed from patients. Seventeen (50%) of the devices tested for zero drift had absolute drifts of at least 3 mmHg. There was no correlation between recorded zero drift and duration of monitoring (r = 0.154, P = 0.207). Five sensors (10% of those tested) failed during patient monitoring and were replaced. Static and dynamic calibration tests of the functioning sensors were within the manufacturer's specifications. However, the sensitivity of the devices to environmental temperature remains a problem. The Camino ICP sensor remains one of the most popular ICP monitoring devices for use in patients with traumatic brain injuries. However, our recent in-house assessment demonstrated the robustness of the device to be less than adequate during routine practice. In this study, more than 50% exhibited zero drift greater than 3 mmHg, which is unacceptable in a catheter tip ICP monitoring device in which zero drift and calibration cannot be checked in vivo. A review of the literature revealed that other available ICP monitoring devices may prove to be more reliable and thus more appropriate for routine clinical measurement of ICP.

  11. On the impact of radiation pressure on the dynamics and inner structure of dusty wind-driven shells

    CERN Document Server

    Martinez-Gonzalez, Sergio; Tenorio-Tagle, Guillermo

    2014-01-01

    Massive young stellar clusters are strong sources of radiation and mechanical energy. Their powerful winds and radiation pressure sweep-up interstellar gas into thin expanding shells which trap the ionizing radiation produced by the central clusters affecting the dynamics and the distribution of their ionized gas. Here we continue our comparison of the star cluster winds and radiation pressure effects on the dynamics of shells around young massive clusters. We calculate the impact that radiation pressure has on the distribution of matter and thermal pressure within such shells as well as on the density weighted ionization parameter $U_w$ and put our results on the diagnostic diagram which allows one to discriminate between the wind-dominated and radiation-dominated regimes. We found that model predicted values of the ionization parameter agree well with typical values found in local starburst galaxies. Radiation pressure may affect the inner structure and the dynamics of wind-driven shells only at the earlies...

  12. Impact of axial velocity and transmembrane pressure (TMP) on ARP filter performance

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-02-29

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. One potential method for increasing filter flux is to adjust the axial velocity and transmembrane pressure (TMP). SRR requested SRNL to conduct bench-scale filter tests to evaluate the effects of axial velocity and transmembrane pressure on crossflow filter flux. The objective of the testing was to determine whether increasing the axial velocity at the ARP could produce a significant increase in filter flux. The authors conducted the tests by preparing slurries containing 6.6 M sodium Salt Batch 6 supernate and 2.5 g MST/L, processing the slurry through a bench-scale crossflow filter unit at varying axial velocity and TMP, and measuring filter flux as a function of time.

  13. Impact Analysis of Dwell Angles on Current Shape and Torque in Switched Reluctance Motors

    Directory of Open Access Journals (Sweden)

    Syeda Fatima Ghousia

    2012-03-01

    Full Text Available The reduction of torque ripple is the main target in research for designing a variable drive system with switched reluctance motors (SRM for higher torque density and better efficiency. This ripple is due to the transition of excitation current between the adjacent phases. Precise control of turn-on and turn off angle is required to smooth the torque. In this paper, the effects of selecting the turn-on and turn-off angles are simulated in detail. It is observed that with the extended turn-on and turn off angles, the precise selection of turn-on and turn off angle can alter the shape of the excitation current in the stator coil and its point of overlapping with the adjacent coil. Therefore the transition between different phases can be smoothed out. The impact of this alteration on the excitation current and torque ripple as a function of different parameters of dwell angle is studied in detail in this paper. It is found that a sinusoidal current shape can also be obtained with the proper selection of these parameters.

  14. Improving Understanding of the Agulhas Current and Its Global Climate Impacts

    Science.gov (United States)

    Beal, Lisa; Biastoch, Arne

    2010-05-01

    Working Group on the Climatic Importance of the Greater Agulhas System; Portland, Oregon, 20-21 February 2010; The first meeting of the new Scientific Committee on Oceanic Research (SCOR) Working Group 136 was held to discuss recent developments in understanding the greater Agulhas Current system and future research directions. The overarching goal of the working group is to improve understanding and awareness of the regional and global climate impacts of the Agulhas Current, a major western boundary current that flows along the east coast of Africa, and its interocean leakage. In addition to studying modern circulation, the working group is motivated by recent paleodata that suggest that through the currents' southern influence on the Atlantic meridional overturning circulation (AMOC), changes in the leakage of warm and salty Agulhas waters into the Atlantic may have triggered the end of ice ages. In terms of global climate, this arguably puts the importance of the greater Agulhas system on a par with Heinrich (land-ice release) events and high-latitude deepwater formation.

  15. IMPACT OF INTERFERENTIAL CURRENT ON PAIN RELIEF AMONG PATIENTS WITH ORCHIALGIA

    Directory of Open Access Journals (Sweden)

    Hany M.I. Elgohary

    2016-08-01

    Full Text Available Background: Scrotal discomfort can contribute to unusual impact on body scheme and result in behavioral alterations, as well as changes in sexual function such as delay of sexual ability that may affect both man and his companion. There are many physiotherapy modalities to reduce the intratesticular pain such as pelvic floor muscle training, hydrotherapy, ultrasound and electrotherapy. Interferential current therapy is a noninvasive therapy used to reduce acute and chronic, post-operative and post-trauma acute pain. It provides a safe and effective alternative to pharmacological approaches to pain control. The purpose of the current study was to investigate the efficacy of interferential current in alleviating testicular pain. Methods: Randomized clinical study conducted on 50 participants. They divided into two equal groups: Group A received interferential current with two electrodes placed over the upper medial aspects of thighs and the other two electrodes were positioned over the suprapubic area. While group B received placebo interferential current. The treatment protocol was applied 3 times/ week for six successive weeks, in a total of 18 sessions. Patients were evaluated before and after the six weeks of the treatment by visual analogue scale and pain intensity while pain relief scale was measured after the treatment. Results: Group A showed a significant pain improvement in both inter and intra group comparison in all measured parameters (visual analogue scale and pain intensity while pain relief scale (p <0.05. Conclusion: The findings show that interferential current is an effective modality and can be recommended for the treatment of testicular pain.

  16. Current progress on understanding the impact of mercury on human health.

    Science.gov (United States)

    Ha, Eunhee; Basu, Niladri; Bose-O'Reilly, Stephan; Dórea, José G; McSorley, Emeir; Sakamoto, Mineshi; Chan, Hing Man

    2017-01-01

    Mercury pollution and its impacts on human health is of global concern. The authors of this paper were members of the Plenary Panel on Human Health in the 12th International Conference on Mercury as a Global Pollutant held in Korea in June 2015. The Panel was asked by the conference organizers to address two questions: what is the current understanding of the impacts of mercury exposure on human health and what information is needed to evaluate the effectiveness of the Minamata Convention in lowering exposure and preventing adverse effects. The authors conducted a critical review of the literature published since January 2012 and discussed the current state-of-knowledge in the following areas: environmental exposure and/or risk assessment; kinetics and biomonitoring; effects on children development; effects on adult general populations; effects on artisanal and small-scale gold miners (ASGM); effects on dental workers; risk of ethylmercury in thimerosal-containing vaccines; interactions with nutrients; genetic determinants and; risk communication and management. Knowledge gaps in each area were identified and recommendations for future research were made. The Panel concluded that more knowledge synthesis efforts are needed to translate the research results into management tools for health professionals and policy makers. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Impacts of current and projected oil palm plantation expansion on air quality over Southeast Asia

    Science.gov (United States)

    Silva, Sam J.; Heald, Colette L.; Geddes, Jeffrey A.; Austin, Kemen G.; Kasibhatla, Prasad S.; Marlier, Miriam E.

    2016-08-01

    Over recent decades oil palm plantations have rapidly expanded across Southeast Asia (SEA). According to the United Nations, oil palm production in SEA increased by a factor of 3 from 1995 to 2010. We investigate the impacts of current (2010) and near-term future (2020) projected oil palm expansion in SEA on surface-atmosphere exchange and the resulting air quality in the region. For this purpose, we use satellite data, high-resolution land maps, and the chemical transport model GEOS-Chem. Relative to a no oil palm plantation scenario (˜ 1990), overall simulated isoprene emissions in the region increased by 13 % due to oil palm plantations in 2010 and a further 11 % in the near-term future. In addition, the expansion of palm plantations leads to local increases in ozone deposition velocities of up to 20 %. The net result of these changes is that oil palm expansion in SEA increases surface O3 by up to 3.5 ppbv over dense urban regions, and in the near-term future could rise more than 4.5 ppbv above baseline levels. Biogenic secondary organic aerosol loadings also increase by up to 1 µg m-3 due to oil palm expansion, and could increase by a further 2.5 µg m-3 in the near-term future. Our analysis indicates that while the impact of recent oil palm expansion on air quality in the region has been significant, the retrieval error and sensitivity of the current constellation of satellite measurements limit our ability to observe these impacts from space. Oil palm expansion is likely to continue to degrade air quality in the region in the coming decade and hinder efforts to achieve air quality regulations in major urban areas such as Kuala Lumpur and Singapore.

  18. Impact of currents and futures altimetric missions on ocean analysis and forecasting

    Science.gov (United States)

    Verrier, Simon; Le Traon, Pierre-Yves; Remy, Elisabeth

    2016-04-01

    Mercator Ocean, as a major operational oceanography center, must adapt its modeling and data assimilation systems regarding new measurements technologies. As satellite altimetry is one of the major observing systems to constrain ocean models, it is a main concern to assess the impact of the current and future altimeter constellation. The study is based on the OSSE/OSE's (Observing System Simulation Experiments/Observing System Experiments) methods. OSSEs are carried out with a global 1/4° modeling and data assimilation system similar to the operational one but using simulated dataset of observations (altimetry here) in order to assess their contribution and to test the sensitivity of results to different parameters (errors, observation density, type of observations). The SAR technology allows a lower measurement noise close to 1 cm and much better than the LRM's 3cm noise. It is important to assess and quantify its impact on operational systems with data assimilation. Simulated data sets are extracted from a global free 1/12° run and assimilated in the global 1/4° modeling and data assimilation system. Using the 1/12° simulation is justified by the fact that mesoscale variability is better represented than in a 1/4° one. OSEs are carried using the operational system where some observations have been retrieved. This technic allows to assess wich is the contribution of each altimeter data set in the whole prediction/analysing system. The main goal is to assess how the reduction of measurement noise (SAR/LRM) and number of satellites impact the analysis and forecast errors at global and regional (i.e. Gulf Stream, Agullas Current) scales.

  19. The Impact of Resonance Frequency Breathing on Measures of Heart Rate Variability, Blood Pressure, and Mood

    Directory of Open Access Journals (Sweden)

    Patrick R. Steffen

    2017-08-01

    Full Text Available Heart rate variability biofeedback (HRVB significantly improves heart rate variability (HRV. Breathing at resonance frequency (RF, approximately 6 breaths/min constitutes a key part of HRVB training and is hypothesized to be a pathway through which biofeedback improves HRV. No studies to date, however, have experimentally examined whether RF breathing impacts measures of HRV. The present study addressed this question by comparing three groups: the RF group breathed at their determined RF for 15 min; the RF + 1 group breathed at 1 breath/min higher than their determined RF for 15 min; and the third group sat quietly for 15 min. After this 15-min period, all groups participated in the Paced Auditory Serial Addition Task (PASAT for 8 min, and then sat quietly during a 10-min recovery period. HRV, blood pressure, and mood were measured throughout the experiment. Groups were not significantly different on any of the measures at baseline. After the breathing exercise, the RF group reported higher positive mood than the other two groups and a significantly higher LF/HF HRV ratio relative to the control group, a key goal in HRVB training (p < 0.05. Additionally, the RF group showed lower systolic blood pressure during the PASAT and during the recovery period relative to the control group, with the RF + 1 group not being significantly different from either group (p < 0.05. Overall, RF breathing appears to play an important role in the positive effect HRVB has on measures of HRV.

  20. Impact of Light Salt Substitution for Regular Salt on Blood Pressure of Hypertensive Patients

    Directory of Open Access Journals (Sweden)

    Carolina Lôbo de Almeida Barros

    2015-02-01

    Full Text Available Background: Studies have shown sodium restriction to have a beneficial effect on blood pressure (BP of hypertensive patients. Objective: To evaluate the impact of light salt substitution for regular salt on BP of hypertensive patients. Methods: Uncontrolled hypertensive patients of both sexes, 20 to 65 years-old, on stable doses of antihypertensive drugs were randomized into Intervention Group (IG - receiving light salt and Control Group (CG - receiving regular salt. Systolic BP (SBP and diastolic BP (DBP were analyzed by using casual BP measurements and Home Blood Pressure Monitoring (HBPM, and sodium and potassium excretion was assessed on 24-hour urine samples. The patients received 3 g of salt for daily consumption for 4 weeks. Results: The study evaluated 35 patients (65.7% women, 19 allocated to the IG and 16 to the CG. The mean age was 55.5 ± 7.4 years. Most participants had completed the Brazilian middle school (up to the 8th grade; n = 28; 80.0%, had a family income of up to US$ 600 (n = 17; 48.6% and practiced regular physical activity (n = 19; 54.3%. Two patients (5.7% were smokers and 40.0% consumed alcohol regularly (n = 14. The IG showed a significant reduction in both SBP and DBP on the casual measurements and HBPM (p < 0.05 and in sodium excretion (p = 0.016. The CG showed a significant reduction only in casual SBP (p = 0.032. Conclusions: The light salt substitution for regular salt significantly reduced BP of hypertensive patients.

  1. Continued Development of Meandering Winding Magnetometer (MWM (Register Trademark)) Eddy Current Sensors for the Health Monitoring, Modeling and Damage Detection of Composite Overwrapped Pressure Vessels

    Science.gov (United States)

    Russell, Richard; Wincheski, Russell; Jablonski, David; Washabaugh, Andy; Sheiretov, Yanko; Martin, Christopher; Goldfine, Neil

    2011-01-01

    Composite Overwrapped Pressure Vessels (COPVs) are used in essentially all NASA spacecraft, launch. vehicles and payloads to contain high-pressure fluids for propulsion, life support systems and science experiments. Failure of any COPV either in flight or during ground processing would result in catastrophic damage to the spacecraft or payload, and could lead to loss of life. Therefore, NASA continues to investigate new methods to non-destructively inspect (NDE) COPVs for structural anomalies and to provide a means for in-situ structural health monitoring (SHM) during operational service. Partnering with JENTEK Sensors, engineers at NASA, Kennedy Space Center have successfully conducted a proof-of-concept study to develop Meandering Winding Magnetometer (MWM) eddy current sensors designed to make direct measurements of the stresses of the internal layers of a carbon fiber composite wrapped COPV. During this study three different MWM sensors were tested at three orientations to demonstrate the ability of the technology to measure stresses at various fiber orientations and depths. These results showed good correlation with actual surface strain gage measurements. MWM-Array technology for scanning COPVs can reliably be used to image and detect mechanical damage. To validate this conclusion, several COPVs were scanned to obtain a baseline, and then each COPV was impacted at varying energy levels and then rescanned. The baseline subtracted images were used to demonstrate damage detection. These scans were performed with two different MWM-Arrays. with different geometries for near-surface and deeper penetration imaging at multiple frequencies and in multiple orientations of the linear MWM drive. This presentation will include a review of micromechanical models that relate measured sensor responses to composite material constituent properties, validated by the proof of concept study, as the basis for SHM and NDE data analysis as well as potential improvements including

  2. The impact of weight reduction therapy on blood pressure levels in Primary Care

    Directory of Open Access Journals (Sweden)

    Daniel Victor Arantes

    2010-11-01

    Full Text Available In the last decades the incidence and prevalence of overweight and obesity are increasing drastically over the world. It is estimated that in Brazil 32% of adults are overweight and 8% obese, totalizing 40% of adults over the weight levels recommended for a healthy life. The situation is even more critical in the low-income population with poor educational level, where the problem is advancing even faster. Obesity figures among the most important risk factors for cardio-vascular diseases and there is strong scientific evidence that even modest weight reduction leads to significant clinical benefits. Thus, offering treatment for overweight and obesity in primary care can evidently improve the health and quality of life of the population and reduce the final public health expenditures. The purpose of this study is to evaluate the applicability and impact of a weight reduction program on the blood pressure levels of a group of patients assisted in a public primary care program called ‘Estratégia de Saúde da Família’ (Family Health Strategy and to propose ways for standardizing this program. A retrospective analytic study was conducted for comparing the clinical data of patients submitted to weight reduction therapy in a public primary care unit called ‘Unidade de Saúde da Família Bandeiras’ in Anápolis, State of Goiás, Brazil. Informed consent from the patients was obtained. Exclusion and inclusion criteria were applied to correct deviations, resulting in a homogeneous sample of 28 patients. Blood pressure and weight levels were obtained before and after the treatment. The arithmetic means of weight, height and blood pressure at the beginning of the treatment were compared with those obtained six months after the treatment was started. There was a mean reduction of 0,64mmHg in the systolic blood pressure (SBP levels and of 0,84mmHg in the diastolic blood pressure (DBP levels for each 1kg of weight loss. These data confirm those found

  3. Population characteristics and impact on heart rate variability,heart rate and blood pressure of passive smoking

    Institute of Scientific and Technical Information of China (English)

    赵菁

    2013-01-01

    Objective To investigate the basic characteristics of passive smoking population,and the impact of passive smoking on heart rate variability,heart rate and blood pressure.Methods Eighty-six passive smokers[mean age: (52.4±7.6) years]were recruited from patients

  4. Driver-Pressure-State-Impact-Response (DPSIR) analysis and risk assessment for soil compaction-A European perspective

    NARCIS (Netherlands)

    Schjønning, Per; Akker, van den J.J.H.; Keller, Thomas; Greve, M.H.; Lamandé, Mathieu; Simojoki, Asko; Stettler, Matthias; Arvidsson, Johan; Breuning-Madsen, Henrik

    2015-01-01

    Compaction of subsoil is a hidden but persistent damage that impairs a range of soil functions and ecosystem services. We analyzed the soil compaction issue in the Driver-Pressure-State-Impact-Response (DPSIR) context. The driving force (DPSIR-D) is the farmers' efforts to sustain economic viabil

  5. Impact of tube current modulation on lesion conspicuity index in hi-resolution chest computed tomography

    Science.gov (United States)

    Szczepura, Katy; Tomkinson, David; Manning, David

    2017-03-01

    Tube current modulation is a method employed in the use of CT in an attempt to optimize radiation dose to the patient. The acceptable noise (noise index) can be varied, based on the level of optimization required; higher accepted noise reduces the patient dose. Recent research [1] suggests that measuring the conspicuity index (C.I.) of focal lesions within an image is more reflective of a clinical reader's ability to perceive focal lesions than traditional physical measures such as contrast to noise (CNR) and signal to noise ratio (SNR). Software has been developed and validated to calculate the C.I. in DICOM images. The aim of this work is assess the impact of tube current modulation on conspicuity index and CTDIvol, to indicate the benefits and limitations of tube current modulation on lesion detectability. Method An anthropomorphic chest phantom was used "Lungman" with inserted lesions of varying size and HU (see table below) a range of Hounsfield units and sizes were used to represent the variation in lesion Hounsfield units found. This meant some lesions had negative Hounsfield unit values.

  6. Determining the Impact of Steady-State PV Fault Current Injections on Distribution Protection

    Energy Technology Data Exchange (ETDEWEB)

    Seuss, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grijalva, Santiago [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    This report investigates the fault current contribution from a single large PV system and the impact it has on existing distribution overcurrent protection devices. Assumptions are made about the modeling of the PV system under fault to perform exhaustive steady - state fault analyses throughout distribution feeder models. Each PV interconnection location is tested to determine how the size of the PV system affects the fault current measured by each protection device. This data is then searched for logical conditions that indicate whether a protection device has operated in a manner that will cause more customer outages due to the addition of the PV system. This is referred to as a protection issue , and there are four unique types of issues that have been identified in the study. The PV system size at which any issues occur are recorded to determine the feeder's PV hosting capacity limitations due to interference with protection settings. The analysis is carried out on six feeder models. The report concludes with a discussion of the prevalence and cause of each protection issue caused by PV system fault current.

  7. The impact of regional economic reliance on the tobacco industry on current smoking in China.

    Science.gov (United States)

    Yang, Tingzhong; Barnett, Ross; Rockett, Ian R H; Yang, Xiaozhao Y; Wu, Dan; Zheng, Weijun; Li, Lu

    2015-05-01

    The purpose of this study was to conduct a preliminary assessment of province of residence and other contextual factors on the likelihood of being a current smoker in China. A cross-sectional, multistage sampling process was used to recruit participants, and their smoking status and sociodemographic characteristics were obtained through face-to-face interviews. The contextual variables were retrieved from a national database. Multilevel logistic regression analysis was performed to assess the impact of provincial economic reliance on the tobacco industry, as well as individual-level characteristics, on the likelihood of being a current smoker. Participants totaled 20,601 from 27 cities located in 26 of the 31 municipalities/provinces in China. Overall smoking prevalence was 31.3% (95% CI: 19.3-33.2%), with rates being highest in Yinchuan City in Ningxia Province (49.8%) and lowest in Shanghai (21.6%). The multilevel analysis showed an excess likelihood of being a current smoker for individuals living in provinces with the highest rate of cigarette production relative to those with the smallest (pmarketing of tobacco products in China. Copyright © 2015. Published by Elsevier Ltd.

  8. Impact of a Diesel High Pressure Common Rail Fuel System and Onboard Vehicle Storage on B20 Biodiesel Blend Stability

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Earl; McCormick, Robert L.; Sigelko, Jenny; Johnson, Stuart; Zickmann, Stefan; Lopes, Shailesh; Gault, Roger; Slade, David

    2016-04-01

    Adoption of high-pressure common-rail (HPCR) fuel systems, which subject diesel fuels to higher temperatures and pressures, has brought into question the efficacy of ASTM International specifications for biodiesel and biodiesel blend oxidation stability, as well as the lack of any stability parameter for diesel fuel. A controlled experiment was developed to investigate the impact of a light-duty diesel HPCR fuel system on the stability of 20% biodiesel (B20) blends under conditions of intermittent use and long-term storage in a relatively hot and dry climate. B20 samples with Rancimat induction periods (IPs) near the current 6.0-hour minimum specification (6.5 hr) and roughly double the ASTM specification (13.5 hr) were prepared from a conventional diesel and a highly unsaturated biodiesel. Four 2011 model year Volkswagen Passats equipped with HPCR fuel injection systems were utilized: one on B0, two on B20-6.5 hr, and one on B20-13.5 hr. Each vehicle was operated over a one-hour drive cycle in a hot running loss test cell to initially stress the fuel. The cars were then kept at Volkswagen's Arizona Proving Ground for two (35 degrees C average daily maximum) to six months (26 degrees C average daily maximum). The fuel was then stressed again by running a portion of the one-hour dynamometer drive cycle (limited by the amount of fuel in the tank). Fuel rail and fuel tank samples were analyzed for IP, acid number, peroxide content, polymer content, and ester profile. The HPCR fuel pumps were removed, dismantled, and inspected for deposits or abnormal wear. Analysis of fuels collected during initial dynamometer tests showed no impact of exposure to HPCR conditions. Long-term storage with intermittent use showed that IP remained above 3 hours, acid number below 0.3 mg KOH/g, peroxides low, no change in ester profile, and no production of polymers. Final dynamometer tests produced only small changes in fuel properties. Inspection of the HPCR fuel pumps revealed no

  9. Perception of the environmental impacts of current and alternative modes of pig production by stakeholder groups.

    Science.gov (United States)

    Petit, Jean; van der Werf, Hayo M G

    2003-08-01

    The current industrial pig production model is in crisis, due to its association with environmental pollution, doubtful product quality and lack of animal well-being. In Bretagne (France), a region of intensive pig production, a survey of seven stakeholder groups concerned with pig production was conducted, as part of a research programme dedicated to the assessment of the environmental impact of different modes of pig production. A very large majority of pig producers (93%) and their suppliers (100%) considers pig farms as an asset for the region, whereas a majority of scientists (58%), activists (78%) and consumers (54%) sees it as a handicap. Differences among stakeholder groups are minor with respect to the perceived importance of environmental and social issues. Stakeholders agree on the relative level of responsibility of pig farms with respect to specific problems. For all groups unpleasant odours and water quality come first with respect to responsibility, for most groups soil quality comes second, followed by product safety and air quality. For a future improved mode of pig production, 76% of pig producers and their suppliers prefer to adapt the current model, for all other groups the majority prefers an alternative model. While pig producers and their suppliers prefer a slurry-based housing system, all other groups prefer a straw-based system. Pig producers see the slurry-based system as technically superior and associate the straw-based system with poor working conditions, whereas consumers associate the slurry-based system in the first place with poor water quality and associate the straw-based system with less pollution. These results will be of use in the research programme on the environmental impact of modes of pig production, as they indicate the environmental impacts to be considered and their relative importance. The results will also help in deciding which options should be assessed. It is concluded that the poor image of the current pig

  10. Influence of Surface Resistivity and Temperature on Variation with Time of Current Pulses in Air at Optimum Pressure

    Directory of Open Access Journals (Sweden)

    S.G. Pimpale

    1977-04-01

    Full Text Available The variation of discharge current pulses with the surface nature of electrodes has been investigated by producing discharge in the intense ionizing zone of two ozonizers (A&B containing pure, dry air at a pressure of 4 & 10mm of mercury respectively. The course of reaction in the tube A showed that the periodic rise and fall of discharge counts through a series of recurrences whose amplitude varied randomly. During this reaction, steady potential, temperature of the electrolytic bath, counting time and pulse height were kept fixed. The phenomenon obtained for both the tubes is produced within a critical range of conditions. The results have been interpreted on the basis of activated adsorption at a temperature of 90 degree and 100 degree Centigrade and discussed on the theoretical grounds of change of surface resistivity upon the glass walls. Use of different coatings on annular surface in the same system with appropriate levels of electrolytic solution for a definite value of height-pulses and temperature, etc. shows significant variations in the discharge counts.

  11. Temperature model for process impact non-uniformity in genipin recovery by high pressure processing.

    Science.gov (United States)

    Ramos-de-la-Peña, Ana Mayela; Montañez, Julio C; Reyes-Vega, María de la Luz; Contreras-Esquivel, Juan Carlos

    2015-11-15

    A model for the process impact temperature non-uniformity during high pressure processing (HPP) of genipap fruit purees was found during genipin recovery. Purees were subjected to HPP (130-530 MPa) under quasi-isobaric non-isothermal conditions (15 min; 0, 4.6 and 9.3mg pectinases/g fruit). Genipin and protein concentration was determined, and pH was measured. Polygalacturonase activity was quantified indirectly by protein content (mg/g fruit). First order kinetics described temperature changes (0-4 min). Polygalacturonase was activated at 130 MPa, inactivated reversibly at 330 MPa and activated again at 530 MPa. Enzyme reaction rate constant (k) was placed in the 0-4 min model and temperature from 2 to 15 min was described. Protein content and pH characterization in terms of decimal reduction time improved highly the 2-15 min model. Since temperature changes were modeled, more insight of its behavior in an HPP reactor was obtained, avoiding uniformity assumptions, making easier the industrial scale HPP implementation.

  12. Impact of mental and physical stress on blood pressure and pulse pressure under normobaric versus hypoxic conditions.

    Science.gov (United States)

    Trapp, Michael; Trapp, Eva-Maria; Egger, Josef W; Domej, Wolfgang; Schillaci, Giuseppe; Avian, Alexander; Rohrer, Peter M; Hörlesberger, Nina; Magometschnigg, Dieter; Cervar-Zivkovic, Mila; Komericki, Peter; Velik, Rosemarie; Baulmann, Johannes

    2014-01-01

    Hypobaric hypoxia, physical and psychosocial stress may influence key cardiovascular parameters including blood pressure (BP) and pulse pressure (PP). We investigated the effects of mild hypobaric hypoxia exposure on BP and PP reactivity to mental and physical stress and to passive elevation by cable car. 36 healthy volunteers participated in a defined test procedure consisting of a period of rest 1, mental stress task (KLT-R), period of rest 2, combined mental (KLT-R) and physical task (bicycle ergometry) and a last period of rest both at Graz, Austria (353 m asl) and at the top station Dachstein (2700 m asl). Beat-to-beat heart rate and BP were analysed both during the test procedures at Graz and at Dachstein and during passive 1000 m elevation by cable car (from 1702 m to 2700 m). A significant interaction of kind of stress (mental vs. combined mental and physical) and study location (Graz vs. Dachstein) was found in the systolic BP (p = .007) and PP (p = .002) changes indicating that during the combined mental and physical stress task sBP was significantly higher under hypoxic conditions whereas sBP and PP were similar during mental stress both under normobaric normoxia (Graz) and under hypobaric hypoxia (Dachstein). During the passive ascent in cable car less trivialization (psychological coping strategy) was associated with an increase in PP (p = .004). Our data show that combined mental and physical stress causes a significant higher raise in sBP and PP under hypoxic conditions whereas isolated mental stress did not affect sBP and PP under hypoxic conditions. PP-reaction to ascent in healthy subjects is not uniform. BP reactions to ascent that represents an accumulation of physical (mild hypobaric hypoxia) and psychological stressors depend on predetermined psychological traits (stress coping strategies). Thus divergent cardiovascular reactions can be explained by applying the multidimensional aspects of the biopsychosocial concept.

  13. Evaluation of the impact of current antismoking advice in the UK on women with planned pregnancies.

    Science.gov (United States)

    Acharya, G; Jauniaux, E; Sathia, Leena; Griffin, M; Morgan, H

    2002-09-01

    Smoking during pregnancy (active or passive) is associated with increased health risks to the unborn child. Current policy on antismoking advice for pregnant women in the United Kingdom is based essentially on written information by means of leaflets given to them at the first antenatal visit. We evaluated the impact of this policy on the smoking habits of pregnant women. A sample of 180 women with planned pregnancies attending antenatal clinics at two teaching hospitals in North London was recruited over a 6-month period. All women were provided with the current antismoking counselling at their first visit at the end of the first trimester and asked to fill in a questionnaire around mid-gestation. The study population included 117 (65%) women who did not currently smoke (non-smokers) and 63 (35%) who were active smokers at the beginning of their pregnancy. Thirty-nine non-smokers were found to be passive smokers. Three women took up smoking during pregnancy. Among the smokers, 53 (84.1%) women made no change in their smoking behaviour during pregnancy, seven (11.1%) reduced their cigarette consumption and only three (4.8%) gave up smoking during the first half of pregnancy. None of the partners changed their smoking habits. All women were aware that smoking in pregnancy could be deleterious to their health and that of their fetus. Despite awareness of dangers of smoking, the prevalence of smoking among pregnant women remains very high after the first antenatal visit and the current antismoking policy based essentially on leaflets is not effective. Health-care professionals should spend more time to inform women adequately about the dangers of smoking and help them to quit before pregnancy.

  14. The impact of mass flow and masking on the pressure drop of air filter in heavy-duty diesel engine

    Directory of Open Access Journals (Sweden)

    Gorji-Bandpy Mofid

    2012-04-01

    Full Text Available This paper presents a computational fluid dynamics (CFD calculation approach to predict and evaluate the impact of the mass-flow inlet on the pressure drop of turbocharger`s air filtfer in heavy-duty diesel engine. The numerical computations were carried out using a commercial CFD program whereas the inlet area of the air filter consisted of several holes connected to a channel. After entering through the channel, the air passes among the holes and enters the air filter. The effect of masking holes and hydraulic diameter is studied and investigated on pressure drop. The results indicate that pressure drop increase with decreasing of hydraulic diameter and masking of the holes has considerable affect on the pressure drop.

  15. The impact of mass flow and masking on the pressure drop of air filter in heavy-duty diesel engine

    Science.gov (United States)

    Hoseeinzadeh, Sepideh; Gorji-Bandpy, Mofid

    2012-04-01

    This paper presents a computational fluid dynamics (CFD) calculation approach to predict and evaluate the impact of the mass-flow inlet on the pressure drop of turbocharger`s air filtfer in heavy-duty diesel engine. The numerical computations were carried out using a commercial CFD program whereas the inlet area of the air filter consisted of several holes connected to a channel. After entering through the channel, the air passes among the holes and enters the air filter. The effect of masking holes and hydraulic diameter is studied and investigated on pressure drop. The results indicate that pressure drop increase with decreasing of hydraulic diameter and masking of the holes has considerable affect on the pressure drop.

  16. IMPACT OF DUCT LEAKAGE PRESSURES ON THE SHAPE OF THE DELTA Q CURVE.

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS,J.W.

    2002-02-01

    The question of whether and to what extent information on the pressures driving duct leaks can be extracted from the data taken during the Delta Q test for duct leakage is investigated. Curves of Delta Q vs. house pressure are generated for sets of cases where the supply and return leakage rates to/from outside are held constant while the leakage pressures are varied. It is found that the Delta Q curve takes on two qualitatively different shapes, one for leakage pressures within the range of house pressures used in the Delta Q test (i.e., -25 Pa to +25 Pa) and the other for leakage pressures well outside this range. These effects are seen in experimental data taken with leakage at known pressures. However, extracting the signal of the leakage pressure from the surrounding noise caused by random measurement variation is likely to be a difficult problem in many cases.

  17. Optimisation of the round window opening in cochlear implant surgery in wet and dry conditions: impact on intracochlear pressure changes.

    Science.gov (United States)

    Mittmann, Philipp; Ernst, A; Mittmann, M; Todt, I

    2016-11-01

    To preserve residual hearing in cochlear implant candidates, the atraumatic insertion of the cochlea electrode has become a focus of cochlea implant research. In a previous study, intracochlear pressure changes during the opening of the round window membrane were investigated. In the current study, intracochlear pressure changes during opening of the round window membrane under dry and transfluid conditions were investigated. Round window openings were performed in an artificial cochlear model. Intracochlear pressure changes were measured using a micro-optical pressure sensor, which was placed in the apex. Openings of the round window membrane were performed under dry and wet conditions using a cannula and a diode laser. Statistically significant differences in the intracochlear pressure changes were seen between the different methods used for opening of the round window membrane. Lower pressure changes were seen by opening the round window membrane with the diode laser than with the cannula. A significant difference was seen between the dry and wet conditions. The atraumatic approach to the cochlea is assumed to be essential for the preservation of residual hearing. Opening of the round window under wet conditions produce a significant advantage on intracochlear pressure changes in comparison to dry conditions by limiting negative outward pressure.

  18. The impact of intrinsic alignment on current and future cosmic shear surveys

    CERN Document Server

    Krause, Elisabeth; Blazek, Jonathan

    2015-01-01

    Intrinsic alignment (IA) of source galaxies is one of the major astrophysical systematics for ongoing and future weak lensing surveys. This paper presents the first forecasts of the impact of IA on cosmic shear measurements for current and future surveys (DES, Euclid, LSST, WFIRST) using simulated likelihood analyses and realistic covariances that include higher-order moments of the density field in the computation. We consider a range of possible IA scenarios and test mitigation schemes, which parameterize IA by the fraction of red galaxies, normalization, luminosity and redshift dependence of the IA signal (for a subset we consider joint IA and photo-z uncertainties). Compared to previous studies we find smaller biases in time-dependent dark energy models if IA is ignored in the analysis; the amplitude and significance of these biases vary as a function of survey properties (depth, statistical uncertainties), luminosity function, and IA scenario: Due to its small statistical errors and relatively shallow ob...

  19. Independent control of ion current and ion impact energy onto electrodes in dual frequency plasma devices

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, P C; Ellingboe, A R; Turner, M M [Plasma Research Laboratory, National Centre for Plasma Science and Technology and School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

    2004-03-07

    Dual frequency capacitive discharges are designed to offer independent control of the flux and energy of ions impacting on an object immersed in a plasma. This is desirable in applications such as the processing of silicon wafers for microelectronics manufacturing. In such discharges, a low frequency component couples predominantly to the ions, while a high frequency component couples predominantly to electrons. Thus, the low frequency component controls the ion energy, while the high frequency component controls the plasma density. Clearly, this desired behaviour is not achieved for arbitrary configurations of the discharge, and in general one expects some unwanted coupling of ion flux and energy. In this paper we use computer simulations with the particle-in-cell method to show that the most important governing parameter is the ratio of the driving frequencies. If the ratio of the high and low frequencies is great enough, essentially independent control of the ion energy and flux is possible by manipulation of the high and low frequency power sources. Other operating parameters, such as pressure, discharge geometry, and absolute power, are of much less significance.

  20. Impacts of UV radiation on plankton community metabolism along the Humboldt Current System

    Directory of Open Access Journals (Sweden)

    N. Godoy

    2011-06-01

    Full Text Available The Humbolt Current System along the Chilean coast is one of the most productive regions in the world, where UV levels are particularly high due to stratospheric ozone depletion. Research has shown that phytoplankton photosynthesis can be severely inhibited by surface radiation and there are concerns that this will reduce not only algal carbon fixation, but also the carbon supply for higher trophic level. Experimental estimates of community metabolism (NCP, GPP and R and the impacts of UV on community metabolism were assessed at 8 stations along the meridional track by the Humbold-2009 cruise (54.80° S–23.85° S on board RV Hespérides from 5 to 15 March 2009. The results showed an increase UVB penetration towards the Equator, along the Humboldt Current System, suggesting a more important impact of UVB radiation towards the north. The metabolic rates observed were within average values reported for the Ocean Pacific and did not show the water mass investigated to be exceptionally productive at the time of the study. Experimental evaluation of the effect of UVB radiation on surface waters, those most strongly affected by UVB, showed that UVB radiation suppressed net community production, resulting in a dominance of heterotrophic communities in surface waters, compared to the prevalence of autotrophic communities inferred when materials, excluding UVB radiation, are used for incubation. These results show that UVB radiation, which has increased greatly in the study area, may have suppressed net community production of the plankton communities, possibly driving plankton communities in the Southwest Pacific towards CO2 sources.

  1. Regional economic impacts of current and proposed management alternatives for Charles M. Russell National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Sexton, Natalie; Ishizaki, Asuka; Ritten, John

    2013-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a refuge and provide long-range guidance and management direction to achieve refuge purposes. Charles M. Russell (CMR) National Wildlife Refuge, located in north-central Montana, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for the Refuge must contain an analysis of expected effects associated with current and proposed refuge-management strategies. For refuge CCP planning, an economic analysis provides a means of estimating how current management (No Action Alternative) and proposed management activities (Alternatives) affect the local economy. This type of analysis provides two critical pieces of information: (1) it illustrates a refuge’s contribution to the local community; and (2) it can help in determining whether economic effects are or are not a real concern in choosing among management alternatives. It is important to note that the economic value of a refuge encompasses more than just the impacts on the regional economy. Refuges also provide substantial nonmarket values (values for items not exchanged in established markets) such as maintaining endangered species, preserving wetlands, educating future generations, and adding stability to the ecosystem (Carver and Caudill, 2007). However, quantifying these types of nonmarket values is beyond the scope of this study. This report first presents a description of the local community and economy near the Refuge. Next, the methods used to conduct a regional economic impact analysis are described. An analysis of the final CCP management strategies that could affect stakeholders and residents and the local economy is then presented. The refuge management activities of economic concern in this analysis are:

  2. Impact of Resin Content on Swelling Pressure of Three Layer Perticleboard Bonded with Urea-Formaldehyde Adhesive

    Directory of Open Access Journals (Sweden)

    Sergej Medved

    2011-03-01

    Full Text Available When particleboards are exposed to water or moist environment, they tend to swell and expand in all directions. The degree of swelling or expansion depends on the type of adhesive used, its share, and the time of exposure and pressure used at hot pressing. The expansion of particleboard, exposed to water or high moisture content, is accompanied by swelling and/or expansion pressure. The purpose of this paper is to present the impact of adhesive share on thickness swelling and swelling pressure of three layer particleboard bonded with ureaformaldehyde adhesive. The resin content was altered in both layers; in core layer it was between 6 and 9 %, and in surface layer between 11 and 13 %. Thickness swelling and swelling pressure were determined with 24-hour immersion test. For the swelling pressure measurement, special force gauge device was used. The biggest changes in swelling and pressure were observed when the resin content was changed in core layer. The fastest change in swelling and swelling pressure was observed in the fi rst few hours after immersion in water.

  3. Crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes

    KAUST Repository

    Wilson, S. K.

    2010-02-26

    Expert opinion was canvassed to identify crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes. Scientists that had published three or more papers on the effects of climate and environmental factors on reef fishes were invited to submit five questions that, if addressed, would improve our understanding of climate change effects on coral reef fishes. Thirty-three scientists provided 155 questions, and 32 scientists scored these questions in terms of: (i) identifying a knowledge gap, (ii) achievability, (iii) applicability to a broad spectrum of species and reef habitats, and (iv) priority. Forty-two per cent of the questions related to habitat associations and community dynamics of fish, reflecting the established effects and immediate concern relating to climate-induced coral loss and habitat degradation. However, there were also questions on fish demographics, physiology, behaviour and management, all of which could be potentially affected by climate change. Irrespective of their individual expertise and background, scientists scored questions from different topics similarly, suggesting limited bias and recognition of a need for greater interdisciplinary and collaborative research. Presented here are the 53 highest-scoring unique questions. These questions should act as a guide for future research, providing a basis for better assessment and management of climate change impacts on coral reefs and associated fish communities.

  4. Crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes.

    Science.gov (United States)

    Wilson, S K; Adjeroud, M; Bellwood, D R; Berumen, M L; Booth, D; Bozec, Y-Marie; Chabanet, P; Cheal, A; Cinner, J; Depczynski, M; Feary, D A; Gagliano, M; Graham, N A J; Halford, A R; Halpern, B S; Harborne, A R; Hoey, A S; Holbrook, S J; Jones, G P; Kulbiki, M; Letourneur, Y; De Loma, T L; McClanahan, T; McCormick, M I; Meekan, M G; Mumby, P J; Munday, P L; Ohman, M C; Pratchett, M S; Riegl, B; Sano, M; Schmitt, R J; Syms, C

    2010-03-15

    Expert opinion was canvassed to identify crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes. Scientists that had published three or more papers on the effects of climate and environmental factors on reef fishes were invited to submit five questions that, if addressed, would improve our understanding of climate change effects on coral reef fishes. Thirty-three scientists provided 155 questions, and 32 scientists scored these questions in terms of: (i) identifying a knowledge gap, (ii) achievability, (iii) applicability to a broad spectrum of species and reef habitats, and (iv) priority. Forty-two per cent of the questions related to habitat associations and community dynamics of fish, reflecting the established effects and immediate concern relating to climate-induced coral loss and habitat degradation. However, there were also questions on fish demographics, physiology, behaviour and management, all of which could be potentially affected by climate change. Irrespective of their individual expertise and background, scientists scored questions from different topics similarly, suggesting limited bias and recognition of a need for greater interdisciplinary and collaborative research. Presented here are the 53 highest-scoring unique questions. These questions should act as a guide for future research, providing a basis for better assessment and management of climate change impacts on coral reefs and associated fish communities.

  5. Impact of current policies on future air quality and health outcomes in Delhi, India

    Science.gov (United States)

    Dholakia, Hem H.; Purohit, Pallav; Rao, Shilpa; Garg, Amit

    2013-08-01

    A key policy challenge in Indian megacities is to curb high concentrations of PM2.5 and mitigate associated adverse health impacts. Using the Greenhouse Gases and Air Pollution Interactions and Synergies (GAINS) model we carry out an integrated analysis of the air quality regulations across different sectors for the city of Delhi. Our findings show that PM2.5 concentrations for Delhi will not reach the recommended national ambient air quality standards (NAAQS) even by 2030 under the current policies scenario. Adopting advanced control technologies reduces PM2.5 concentrations by about 60% and all-cause mortality by half in 2030. Climate change mitigation policies significantly reduce greenhouse gases, but have a modest impact on reducing PM2.5 concentrations. Stringent policies to control the net flow of air pollution from trans-boundary sources will play a crucial role in reducing pollution levels in Delhi city. Achieving NAAQS requires a stringent policy portfolio that combines advanced control technologies with a switch to cleaner fuels and the control of trans-boundary pollution.

  6. Impact of antipsychotic medication on transcranial direct current stimulation (tDCS) effects in schizophrenia patients.

    Science.gov (United States)

    Agarwal, Sri Mahavir; Bose, Anushree; Shivakumar, Venkataram; Narayanaswamy, Janardhanan C; Chhabra, Harleen; Kalmady, Sunil V; Varambally, Shivarama; Nitsche, Michael A; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

    2016-01-30

    Transcranial direct current stimulation (tDCS) has generated interest as a treatment modality for schizophrenia. Dopamine, a critical pathogenetic link in schizophrenia, is also known to influence tDCS effects. We evaluated the influence of antipsychotic drug type (as defined by dopamine D2 receptor affinity) on the impact of tDCS in schizophrenia. DSM-IV-TR-diagnosed schizophrenia patients [N=36] with persistent auditory hallucinations despite adequate antipsychotic treatment were administered add-on tDCS. Patients were divided into three groups based on the antipsychotic's affinity to D2 receptors. An auditory hallucinations score (AHS) was measured using the auditory hallucinations subscale of the Psychotic Symptom Rating Scales (PSYRATS). Add-on tDCS resulted in a significant reduction inAHS. Antipsychotic drug type had a significant effect on AHS reduction. Patients treated with high affinity antipsychotics showed significantly lesser improvement compared to patients on low affinity antipsychotics or a mixture of the two. Furthermore, a significant sex-by-group interaction occurred; type of medication had an impact on tDCS effects only in women. Improvement differences could be due to the larger availability of the dopamine receptor system in patients taking antipsychotics with low D2 affinity. Sex-specific differences suggest potential estrogen-mediated effects. This study reports a first-time observation on the clinical utility of antipsychotic drug type in predicting tDCS effects in schizophrenia.

  7. Impact Analysis of The Current English Curriculum for English Majors at The Elementary Stage

    Institute of Scientific and Technical Information of China (English)

    李轶群

    2015-01-01

    Besides the tremendous changes that happened to English education during the latest decade,socialist market economy has also made new requests for the cultivated pattern of English majors in our country.Commissioned by Ministry of Education,English branch of College Foreign Languages Teaching Instructed Committee drafted and handed in new curriculum in 1999,which has been implemented since the year of 2000.Even though the new curriculum has been implemented for several years already,there are still some people who have different opinions towards it.This research takes English majors from the second year and the fourth year as the informants,and investigates the impressions,opinions and impacts of the new curriculum in students’ mind.And then qualitatively analyzes the collected data.Based on both positive and negative impacts analysis of the new curriculum on English majors at the elementary stage,this paper also brings forward some suggestions,which may help the improvement of current curriculum.

  8. The impact of current visa regime policy on tourism recovery and development in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Nelson Zengeni

    2012-12-01

    Full Text Available This paper reports the results on the impact of the current visa regime policy on tourism recovery and development in Zimbabwe. The focus was on finding out how the visa regime could impact on efforts to bring into the country more visitors following the decline in visitor inflows from 2000 to 2008. Data was collected from selected visitors from different member states which require visas to enter into the county in the period between January 2010 and July 2010.The findings shows that visa restrictions play a small part in discouraging visitors to visit Zimbabwe. The visa regime policy was designed in such a way that it was easy for passport holders from traditional markets to have relatively easy passage into Zimbabwe. It was also discovered that visa restrictions were part of international travel conditions but how to get the visa became the competitive advantage or disadvantage a destination can have compared with its competitors. Zimbabwe’s traditional markets believed that the visa was not difficult to get nor was it too expensive as to scare away visitors. However, the emerging markets such as China who are in Group C had problems getting the visa as they were required to apply for the visa before traveling to Zimbabwe.

  9. Estimating the impacts of fishing on dependent predators: a case study in the California Current.

    Science.gov (United States)

    Field, J C; MacCall, A D; Bradley, R W; Sydeman, W J

    2010-12-01

    Juvenile rockfish (Sebastes spp.) are important prey to seabirds in the California Current System, particularly during the breeding season. Both seabird breeding success and the abundance of pelagic juvenile rockfish show high interannual variability. This covariation is largely a response to variable ocean conditions; however, fishing on adult rockfish may have had consequences for seabird productivity (e.g., the number of chicks fledged per breeding pair) by reducing the availability of juvenile rockfish to provisioning seabird parents. We tested the hypothesis that fishing has decreased juvenile rockfish availability and thereby limited seabird productivity over the past 30 years. We quantified relationships between observed juvenile rockfish relative abundance and seabird productivity, used fisheries stock assessment approaches to estimate the relative abundance of juvenile rockfish in the absence of fishing, and compared the differences in seabird productivity that would have resulted without rockfish fisheries. We examined the abundance of juvenile rockfish and the corresponding productivity of three seabird species breeding on Southeast Farallon Island (near San Francisco, California, USA) from the early 1980s to the present. Results show that while the relative abundance of juvenile rockfish has declined to approximately 50% of the estimated unfished biomass, seabirds achieved 75-95% of the estimated un-impacted levels of productivity, depending upon the species of bird and various model assumptions. These results primarily reflect seabirds with "conservative" life histories (one egg laid per year) and may be different for species with more flexible life history strategies (greater reproductive effort). Our results are consistent with the premise that the impacts of local rockfish fisheries on seabird productivity are less than impacts that have occurred to the prey resources themselves due to ocean climate and the ability of seabirds to buffer against

  10. Impact of laryngeal mask airway cuff pressures on the incidence of sore throat in children.

    Science.gov (United States)

    Wong, Justin Gin Leong; Heaney, Mairead; Chambers, Neil A; Erb, Thomas O; von Ungern-Sternberg, Britta S

    2009-05-01

    Hyperinflation of laryngeal mask airway cuffs can cause harm to the upper airway mainly by exerting high pressures on pharyngeal and laryngeal structures thus impairing mucosal perfusion. Although cuff manometers can be used to guide the monitoring of cuff pressures, their use is not routine in many institutions. In a prospective audit, we assessed the incidence of sore throat following day-case-surgery in relation to the intracuff pressure within the laryngeal mask airway. Four hundred children (3-21 years) were consecutively included in this study. The laryngeal mask airway was inflated as deemed necessary by the attending anesthetist. Cuff pressures were measured using a calibrated cuff manometer (Portex Limited, Hythe, Kent, UK, 0-120 cm H2O, pressures exceeding the measurement range were set at 140 cm H2O for statistical purposes) at induction of anesthesia. Forty-five children (11.25%) developed sore throat, 32 (8%) sore neck and 17 (4.25%) sore jaw. Of those that developed sore throat, 56.5% had cuff pressures exceeding >100 cm H2O. In contrast, when cuff pressures were sore throat, whilst there was only a 4.6% occurrence of sore throat if cuff pressures were between 40-60 cm H2O. We have demonstrated that intra cuff pressure in laryngeal mask airways is closely related to the development of sore throat with higher pressures increasing its likelihood. Hence, cuff pressures should be measured routinely using a manometer to minimize the incidence of sore throat.

  11. Dissolving current gaps in entrepreneurship education and its impact on business development in Slovakia

    Directory of Open Access Journals (Sweden)

    Helena Majdúchová

    2015-10-01

    Full Text Available This paper presents partial outcomes of the research conducted under the cover of the project “V4 Scientific Centers for the Enhancement of Financial Literacy and Entrepreneurship Education“, International Visegrad Fund, Standard Grant No. 21410134. In this paper we focus on dissolving current gaps in entrepreneurship education and its impact on business development in Slovakia (one of participating countries. We do so by using the whole variety of research methods, including structured survey, direct observation, decomposition, implication, etc. We are dealing with the identification of the university education attributes important for the entrepreneurial competences development, followed by further insights into the specific area - university support of individual initiative and entrepreneurial thinking. To avoid the subjective dimension of research outcome, we look at it from two different points of view – students and teachers perceptions. We also use a cross-cultural approach and different cultural dimensions to identify the general perception of normal state of this attribute in the society. The last part of this paper summarizes our recommendations intending to improve the current state of university education system in the field of entrepreneurial competences development.

  12. The impact of calcium current reversal on neurotransmitter release in the electrically stimulated retina

    Science.gov (United States)

    Werginz, Paul; Rattay, Frank

    2016-08-01

    Objective. In spite of intense theoretical and experimental investigations on electrical nerve stimulation, the influence of reversed ion currents on network activity during extracellular stimulation has not been investigated so far. Approach. Here, the impact of calcium current reversal on neurotransmitter release during subretinal stimulation was analyzed with a computational multi-compartment model of a retinal bipolar cell (BC) that was coupled with a four-pool model for the exocytosis from its ribbon synapses. Emphasis was laid on calcium channel dynamics and how these channels influence synaptic release. Main results. Stronger stimulation with anodic pulses caused transmembrane voltages above the Nernst potential of calcium in the terminals and, by this means, forced calcium ions to flow in the reversed direction from inside to the outside of the cell. Consequently, intracellular calcium concentration decreased resulting in a reduced vesicle release or preventing release at all. This mechanism is expected to lead to a pronounced ring-shaped pattern of exocytosis within a group of neighbored BCs when the stronger stimulated cells close to the electrode fail in releasing vesicles. Significance. Stronger subretinal stimulation causes failure of synaptic exocytosis due to reversal of calcium flow into the extracellular space in cells close to the electrode.

  13. A comparative study: the impact of different lipid extraction methods on current microalgal lipid research.

    Science.gov (United States)

    Li, Yan; Ghasemi Naghdi, Forough; Garg, Sourabh; Adarme-Vega, Tania Catalina; Thurecht, Kristofer J; Ghafor, Wael Abdul; Tannock, Simon; Schenk, Peer M

    2014-01-24

    Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO₂ extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research.

  14. Impact of current speed on mass flux to a model flexible seagrass blade

    Science.gov (United States)

    Lei, Jiarui; Nepf, Heidi

    2016-07-01

    Seagrass and other freshwater macrophytes can acquire nutrients from surrounding water through their blades. This flux may depend on the current speed (U), which can influence both the posture of flexible blades (reconfiguration) and the thickness of the flux-limiting diffusive layer. The impact of current speed (U) on mass flux to flexible blades of model seagrass was studied through a combination of laboratory flume experiments, numerical modeling and theory. Model seagrass blades were constructed from low-density polyethylene (LDPE), and 1, 2-dichlorobenzene was used as a tracer chemical. The tracer mass accumulation in the blades was measured at different unidirectional current speeds. A numerical model was used to estimate the transfer velocity (K) by fitting the measured mass uptake to a one-dimensional diffusion model. The measured transfer velocity was compared to predictions based on laminar and turbulent boundary layers developing over a flat plate parallel to flow, for which K∝U0.5 and ∝U, respectively. The degree of blade reconfiguration depended on the dimensionless Cauchy number, Ca, which is a function of both the blade stiffness and flow velocity. For large Ca, the majority of the blade was parallel to the flow, and the measured transfer velocity agreed with laminar boundary layer theory, K∝U0.5. For small Ca, the model blades remained upright, and the flux to the blade was diminished relative to the flat-plate model. A meadow-scale analysis suggests that the mass exchange at the blade scale may control the uptake at the meadow scale.

  15. Bottom pressure, vertical acoustic round-trip travel time, and near-bottom currents data collected by Current-and-Pressure-recording Inverted Echo Sounders (CPIES), as part of the Kuroshio Extension System Study (KESS), from 26 April 2004 to 25 June 2006 in the Kuroshio Extension east of Japan (NODC Accession 0073269)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains Current and Pressure recording Inverted Echo Sounder (CPIES) measurements collected during the Kuroshio Extension System Study (KESS) under...

  16. Temperature profile, current, pressure, physical, and other data from XBT casts, current meters, pressure gauges, and CTD casts from the VEGA I and other platforms from the Coastal Waters of California and other locations as part of the Central California Circulation Study from 1984-01-31 to 1985-07-01 (NCEI Accession 8700197)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile, current, pressure, physical, and other data from the VEGA I and other platforms from the Coastal Waters of California and other locations from...

  17. Episodic Sediment Failure in Northern Flemish Pass, Eastern Canadian Margin: Interplay of Seismicity, Contour Current Winnowing, and Excess Pore Pressures

    Science.gov (United States)

    Piper, D.

    2015-12-01

    Episodic sediment failures are recognised on continental slopes around Flemish Pass and Orphan Basin from multibeam bathymetry, seismic reflection profiles and piston cores. Seismic stratigraphy is tied to published long cores with O-isotope data back to before MIS 6 and carbonate rich Heinrich layers in places produce marker reflections in high-resolution sparker profiles. Heinrich layers, radiocarbon dates and peaks in diatom abundance provide core chronology. Slope sedimentation was strongly influenced by the Labrador Current and the silty muds show architecture characteristic of contourites. Variation in Labrador Current strength is known from the sortable silt proxy over the past 125 ka. Large slope failures were mapped from seismic reflection profiles and their age estimated from seismic stratigraphy (3-5 ka resolution) and in some cases refined from cores (1-3 ka resolution). Large slope failures occurred apparently synchronously over margin lengths of 50-350 km. Such failures were earthquake triggered: other mechanisms for producing laterally extensive synchronous failure do not apply. Triaxial shear measurements show a Su/σ' ratio of typical slope sediment of 0.48, implying considerable stability. However, some silty muds have Atterberg limits that suggest susceptibility to liquefaction under cyclic loading, particularly in Holocene deposits and by analogy those of past full interglacials. Basal failure planes of some large failures correspond with either the last interglacial or the MIS 6 glacial maximum. Comparison with seismological models suggests that the observed slope failures represent earthquakes ranging from Mw ~5.6 to ~7.6. Mean recurrence interval of M = 7 earthquakes at any point on the margin is estimated at 30 ka from seismological models and 40 ka from the sediment failure record. In northern Flemish Pass, a spatial cluster of several failures over 30 ka preceded by a long interval with no failures suggests that some other mechanism has

  18. Thermodynamic analysis of energy density in pressure retarded osmosis: The impact of solution volumes and costs

    Energy Technology Data Exchange (ETDEWEB)

    Reimund, Kevin K. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Chemical and Biomolecular Engineering; McCutcheon, Jeffrey R. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Chemical and Biomolecular Engineering; Wilson, Aaron D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    A general method was developed for estimating the volumetric energy efficiency of pressure retarded osmosis via pressure-volume analysis of a membrane process. The resulting model requires only the osmotic pressure, π, and mass fraction, w, of water in the concentrated and dilute feed solutions to estimate the maximum achievable specific energy density, uu, as a function of operating pressure. The model is independent of any membrane or module properties. This method utilizes equilibrium analysis to specify the volumetric mixing fraction of concentrated and dilute solution as a function of operating pressure, and provides results for the total volumetric energy density of similar order to more complex models for the mixing of seawater and riverwater. Within the framework of this analysis, the total volumetric energy density is maximized, for an idealized case, when the operating pressure is π/(1+√w⁻¹), which is lower than the maximum power density operating pressure, Δπ/2, derived elsewhere, and is a function of the solute osmotic pressure at a given mass fraction. It was also found that a minimum 1.45 kmol of ideal solute is required to produce 1 kWh of energy while a system operating at “maximum power density operating pressure” requires at least 2.9 kmol. Utilizing this methodology, it is possible to examine the effects of volumetric solution cost, operation of a module at various pressure, and operation of a constant pressure module with various feed.

  19. Identifying the impact of climate and anthropic pressures on karst aquifers using wavelet analysis

    Science.gov (United States)

    Charlier, Jean-Baptiste; Ladouche, Bernard; Maréchal, Jean-Christophe

    2015-04-01

    This paper assesses the implications of climate and anthropic pressures on short to long-term changes in water resources in a Mediterranean karst using wavelet analysis. This approach was tested on 38-year (1974-2011) hydrogeological time series recorded at the Lez spring (South France), which is exploited for water supply. Firstly, we investigated inter-relationships in the frequency domain by cross-correlation across multiresolution levels. Our results showed that rainfall and spring discharge are highly correlated in the high frequency domain which reflects the hydrogeological response during flood events of typical highly karstified systems. Pumping and groundwater level are correlated in a lower frequency domain, illustrating seasonal to multi-year relationships. Secondly, continuous wavelet transform was applied to characterize the temporal variability of the inter-relationships involved. On the contrary to examples of "non-managed" karst aquifers in the literature, our results showed that the 10-year rainfall component was attenuate in the discharge signal. We assume that the reason is that the storage variations are strongly affected by pumping. This interesting result shows that possible long-term impacts of rainfall variability due to climate change may be masked by a high pumping rate. We showed also that despite an increase of the pumping rate from the 1980s, the stress on the groundwater resource does not increase from year to year. The present pumping strategy does not affect the drawdown in the long term, avoiding an over-exploitation of the aquifer. Finally, this study highlights the effectiveness of wavelet analysis in characterizing the response variability of karst systems where the hydrogeological regime is modified by pumping.

  20. Impact of chemical peeling combined with negative pressure on human skin.

    Science.gov (United States)

    Kim, S J; Kang, I J; Shin, M K; Jeong, K H; Baek, J H; Koh, J S; Lee, S J

    2016-10-01

    In vivo changes in skin barrier function after chemical peeling with alpha hydroxyacids (AHAs) have been previously reported. However, the additional effects of physical treatment with chemical agents on skin barrier function have not been adequately studied. This study measured the degree of acute skin damage and the time required for skin barrier repair using non-invasive bioengineering methods in vivo with human skin to investigate the additional effect of a 4% AHA chemical jet accelerated at supersonic velocities. Thirteen female subjects (average age: 29.54 ± 4.86 years) participated in this study. The faces of the subjects were divided into half according to the block randomization design and were then assigned to receive AHA peeling alone or AHA peeling combined with pneumatic pressure on each side of the face. Transepidermal water loss (TEWL), skin colour and skin blood flow were evaluated at baseline and at 30 min, 2, 5 and 7 days after treatment. The TEWL and skin blood flow were significantly increased after 30 min in chemodermabrasion compared with chemical peeling alone (P skin blood flow recovered to baseline after 2 days, and TEWL was significantly decreased at 7 days compared with chemical peeling alone (P skin barriers, but it is estimated that it can enhance the skin barrier function after 7 days compared to the use of a chemical agent alone. In addition, chemodermabrasion has a more effective impact in the dermis and relatively preserves the skin barrier. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  1. Simultaneous visualization of oxygen partial pressure, current density, and water droplets in serpentine fuel cell during power generation for understanding reaction distributions

    Science.gov (United States)

    Takanohashi, Kazuhiro; Suga, Takeo; Uchida, Makoto; Ueda, Toshihide; Nagumo, Yuzo; Inukai, Junji; Nishide, Hiroyuki; Watanabe, Masahiro

    2017-03-01

    Understanding the reaction distributions inside a polymer electrolyte fuel cell (PEFC) is essential for the higher performance and durability. We have developed a new see-through cell and visualized the distributions of oxygen partial pressure and current density inside a running PEFC at the temperature of 40 and 80 °C and the relative humidity of 53%. The oxygen utilization was changed from 0% to 80% by changing the current density. At higher oxygen utilizations, the current density was higher and therefore the water generation. Generated water droplets in the flow channel were also visualized, allowing for the simultaneous visualization of the distribution of the oxygen partial pressure, current density, and water droplets. By combining the observations of all three parameters, the reactions inside a membrane-electrode assembly were discussed.

  2. Impact of AT2-receptor stimulation on vascular biology, kidney function, and blood pressure

    Directory of Open Access Journals (Sweden)

    Danyel LA

    2013-11-01

    Full Text Available Leon A Danyel,1 Patrick Schmerler,1 Ludovit Paulis,1–3 Thomas Unger,4 U Muscha Steckelings1,5 1Center for Cardiovascular Research, Institute of Pharmacology, Charité Medical Faculty, Berlin, Germany; 2Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic; 3Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Bratislava, Slovak Republic; 4CARIM, Maastricht University, Maastricht, the Netherlands; 5Institute of Molecular Medicine, Department of Cardiovascular and Renal Physiology, University of Southern Denmark, Odense, Denmark Abstract: The angiotensin type 2 receptor (AT2R and the receptor MAS are receptors within the renin–angiotensin system, which mediate tissue-protective actions such as anti-inflammation, antifibrosis, and antiapoptosis. In recent years, several programs have been launched in order to develop drugs that act as agonists on the AT2R or MAS to take therapeutic advantage of the protective and regenerative properties of these receptors. This review article will focus on recent data obtained in preclinical animal and in vitro models with new AT2R-agonistic molecules (Compound 21 and β-amino acid substituted angiotensin II and with relevance for blood pressure (BP regulation or hypertensive end-organ damage. These data will include studies on vasodilation/vasoconstriction in isolated resistance arteries ex vivo, studies on kidney function, studies on vascular remodeling, and studies that measured the net effect of AT2R stimulation on BP in vivo. Current data indicate that although AT2R stimulation causes vasodilation ex vivo and promotes natriuresis, it does not alter BP levels in vivo acutely – at least as long as there is no additional low-dose blockade of AT1R. However, AT2R stimulation alone is able to attenuate hypertension-induced vascular remodeling and reduce arterial stiffening, which in more chronic settings and together with the natriuretic

  3. Impact of ventilation frequency and parenchymal stiffness on flow and pressure distribution in a canine lung model.

    Science.gov (United States)

    Amini, Reza; Kaczka, David W

    2013-12-01

    To determine the impact of ventilation frequency, lung volume, and parenchymal stiffness on ventilation distribution, we developed an anatomically-based computational model of the canine lung. Each lobe of the model consists of an asymmetric branching airway network subtended by terminal, viscoelastic acinar units. The model allows for empiric dependencies of airway segment dimensions and parenchymal stiffness on transpulmonary pressure. We simulated the effects of lung volume and parenchymal recoil on global lung impedance and ventilation distribution from 0.1 to 100 Hz, with mean transpulmonary pressures from 5 to 25 cm H2O. With increasing lung volume, the distribution of acinar flows narrowed and became more synchronous for frequencies below resonance. At higher frequencies, large variations in acinar flow were observed. Maximum acinar flow occurred at first antiresonance frequency, where lung impedance achieved a local maximum. The distribution of acinar pressures became very heterogeneous and amplified relative to tracheal pressure at the resonant frequency. These data demonstrate the important interaction between frequency and lung tissue stiffness on the distribution of acinar flows and pressures. These simulations provide useful information for the optimization of frequency, lung volume, and mean airway pressure during conventional ventilation or high frequency oscillation (HFOV). Moreover our model indicates that an optimal HFOV bandwidth exists between the resonant and antiresonant frequencies, for which interregional gas mixing is maximized.

  4. On the impact of radiation pressure on the dynamics and inner structure of dusty wind-driven shells

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-González, Sergio; Silich, Sergiy; Tenorio-Tagle, Guillermo, E-mail: silich@inaoep.mx [Instituto Nacional de Astrofísica Óptica y Electrónica, AP 51, 72000 Puebla (Mexico)

    2014-04-20

    Massive young stellar clusters are strong sources of radiation and mechanical energy. Their powerful winds and radiation pressure sweep up interstellar gas into thin expanding shells that trap the ionizing radiation produced by the central clusters affecting the dynamics and the distribution of their ionized gas. Here we continue our comparison of the star cluster winds and radiation pressure effects on the dynamics of shells around young massive clusters. We calculate the impact that radiation pressure has on the distribution of matter and thermal pressure within such shells, as well as on the density-weighted ionization parameter U{sub w} , and put our results on the diagnostic diagram, which allows one to discriminate between the wind-dominated and radiation-dominated regimes. We found that model-predicted values of the ionization parameter agree well with typical values found in local starburst galaxies. Radiation pressure may affect the inner structure and the dynamics of wind-driven shells, but only during the earliest stages of evolution (before ∼3 Myr) or if a major fraction of the star cluster mechanical luminosity is dissipated or radiated away within the star cluster volume and thus the star cluster mechanical energy output is significantly smaller than star cluster synthetic models predict. However, even in these cases radiation dominates over the wind dynamical pressure only if the exciting cluster is embedded into a high-density ambient medium.

  5. Impact of catheter on uroflow rate in pressure-flow study

    Institute of Scientific and Technical Information of China (English)

    张鹏; 武治津; 高居忠

    2004-01-01

    @@ The importance of a pressure-flow study in the diagnostic work-up of patients suffering from benign prostatic hyperplasia (BPH) has been recognized. However, there is still uncertainty regarding the role the catheter might play in affecting uroflow rate during a pressure-flow study. In this present study, we retrospectively analyzed voiding data from pressure-flow studies taken before and after catheterization in 44 patients suffering from BPH to investigate whether catheterization has an effect on uroflow rate.

  6. Technology trends in high temperature pressure transducers: The impact of micromachining

    Science.gov (United States)

    Mallon, Joseph R., Jr.

    1992-01-01

    This paper discusses the implications of micromachining technology on the development of high temperature pressure transducers. The introduction puts forth the thesis that micromachining will be the technology of choice for the next generation of extended temperature range pressure transducers. The term micromachining is defined, the technology is discussed and examples are presented. Several technologies for high temperature pressure transducers are discussed, including silicon on insulator, capacitive, optical, and vibrating element. Specific conclusions are presented along with recommendations for development of the technology.

  7. Comparing snow models under current and future climates: Uncertainties and implications for hydrological impact studies

    Science.gov (United States)

    Troin, Magali; Poulin, Annie; Baraer, Michel; Brissette, François

    2016-09-01

    Projected climate change effects on snow hydrology are investigated for the 2041-2060 horizon following the SRES A2 emissions scenario over three snowmelt-dominated catchments in Quebec, Canada. A 16-member ensemble of eight snow models (SM) simulations, based on the high-resolution Canadian Regional Climate Model (CRCM-15 km) simulations driven by two realizations of the Canadian Global Climate Model (CGCM3), is established per catchment. This study aims to compare a range of SMs in their ability at simulating snow processes under current climate, and to evaluate how they affect the assessment of the climate change-induced snow impacts at the catchment scale. The variability of snowpack response caused by the use of different models within two different SM approaches (degree-day (DD) versus mixed degree-day/energy balance (DD/EB)) is also evaluated, as well as the uncertainty of natural climate variability. The simulations cover 1961-1990 in the present period and 2041-2060 in the future period. There is a general convergence in the ensemble spread of the climate change signals on snow water equivalent at the catchment scale, with an earlier peak and a decreased magnitude in all basins. The results of four snow indicators show that most of the uncertainty arises from natural climate variability (inter-member variability of the CRCM) followed by the snow model. Both the DD and DD/EB models provide comparable assessments of the impacts of climate change on snow hydrology at the catchment scale.

  8. On the role of electron impact in an atmospheric-pressure microwave discharge in liquid n-heptane

    Science.gov (United States)

    Lebedev, Yu. A.; Tatarinov, A. V.; Epstein, I. L.

    2017-04-01

    The role of electron impact in the dissociation of n-heptane in an atmospheric-pressure microwave discharge in liquid n-heptane was investigated using a self-consistent two-dimensional model. The model includes the Navier-Stokes equations for a two-phase subsonic flow of incompressible liquid and compressible gas, the heat conduction equation, Maxwell's equations for the microwave field, the Boltzmann equation for plasma electrons, and the balance equations for the electron density and weight fraction of n-heptane in the gaseous and liquid phases. It is shown that the effect of electron impact is negligible at times longer than 10-3 s.

  9. Does superior caval vein pressure impact head growth in Fontan circulation?

    Science.gov (United States)

    Trachsel, Tina; Balmer, Christian; Wåhlander, Håkan; Weber, Roland; Dave, Hitendu; Poretti, Andrea; Kretschmar, Oliver; Cavigelli-Brunner, Anna

    2016-10-01

    Patients with bidirectional cavopulmonary anastomosis have unphysiologically high superior caval vein pressure as it equals pulmonary artery pressure. Elevated superior caval vein pressure may cause communicating hydrocephalus and macrocephaly. This study analysed whether there exists an association between head circumference and superior caval vein pressure in patients with single ventricle physiology. We carried out a retrospective analysis of infants undergoing Fontan completion at our institution from 2007 to 2013. Superior caval vein pressures were measured during routine catheterisation before bidirectional cavopulmonary anastomosis and Fontan completion as well as head circumference, adjusted to longitudinal age-dependent percentiles. We included 74 infants in our study. Median ages at bidirectional cavopulmonary anastomosis and Fontan were 4.8 (1.6-12) and 27.9 (7-40.6) months, respectively. Head circumference showed significant growth from bidirectional cavopulmonary anastomosis until Fontan completion (7th (0-100th) versus 20th (0-100th) percentile). There was no correlation between superior caval vein pressure and head circumference before Fontan (R2=0.001). Children with lower differences in superior caval vein pressures between pre-bidirectional cavopulmonary anastomosis and pre-Fontan catheterisations showed increased growth of head circumference (R2=0.19). Patients with moderately elevated superior caval vein pressure associated with single ventricle physiology did not have a tendency to develop macrocephaly. There is no correlation between superior caval vein pressure before Fontan and head circumference, but between bidirectional cavopulmonary anastomosis and Fontan head circumference increases significantly. This may be explained by catch-up growth of head circumference in patients with more favourable haemodynamics and concomitant venous pressures in the lower range. Further studies with focus on high superior caval vein pressures are needed to

  10. Big Feet: Assessing the Current and Future Impact of Population Size on a Country's Ecological Footprint

    Science.gov (United States)

    Hogg, R. S.; Takaro, T.; Miller, C.; Hogg, E.; Anema, A.; Gislason, M.; Parkes, M.

    2015-12-01

    Background: Ecological footprints assess the land and water a population needs to procure its resources and handle its waste. Measures derived from these footprints look at a population's ecological overshoot rather than weighting the population to its footprint. The aim of this study was to examine the latter approach by determining what the current and future weighted world population, by income gradient, would be if everyone lived within the boundary of 1.8 hectares per person. Methods: Country-specific ecological footprints and populations for 2007 were obtained from the Global Footprint Network (www.footprintnetwork.org); and projected populations were collected from US Census Bureau (www.census.gov). Footprint growth to 2050 was based on a business as usual approach developed by Kitzes et al. in Phil. Trans. R. Soc. B (2008). Weighted population estimates were derived by multiplying actual population by the ratio of the country's footprint to overall boundary of 1.8 hectares per person. Results: The weighted global population increased by 2.4 billion people (37%) in 2007 based on our adjustment. High and middle-income country populations increased, by 242% and 10%, respectively, while low-income country populations decreased by 33%. The weighed global population in 2050 increased by 10.1 billion with the majority of this growth occurring in high-income countries -- 437% versus 67% and 9% respectively for medium and low-income countries. Conclusions: Our study showed that current and future global weighted demographic and ecological impact would be felt mainly in high-income countries even though actual population growth would occur mainly in low and middle-income countries.

  11. Impact of Current and Emerging Glucose-Lowering Drugs on Body Weight in Type 2 Diabetes.

    Science.gov (United States)

    Lau, David C W; Teoh, Hwee

    2015-12-01

    Type 2 diabetes is a progressive disease, and most people with diabetes will eventually require adjunctive pharmacotherapy to optimize their glycemic control. As the majority of people with type 2 diabetes are overweight or obese, weight management is an essential component of diabetes management to improve their overall health and quality of life. Many of the currently available glucose-lowering drugs are associated with weight gain, which makes it challenging for both prescribing clinicians and patients. The 2015 Canadian Diabetes Association Clinical Practice Guidelines interim update on the pharmacologic management of type 2 diabetes recommend individualization of therapy and glycemic targets. Clinicians should take into consideration not only the drug's efficacy and safety profiles but also its propensity for causing hypoglycemia and weight gain. Given that the number of glucose-lowering drugs is expanding rapidly, a better understanding of the impacts of current and emerging therapies on body weight will serve as a useful guide. Metformin remains the first-line drug after diet and exercise therapy. The next add-on agent could be selected from the incretin or sodium-glucose cotransporter-2 inhibitor class because these drugs rarely cause hypoglycemia and may lead to modest weight loss. When insulin therapy is considered, choosing a basal insulin that is associated with less nocturnal hypoglycemia and weight gain is recommended. Emerging therapies using combination therapy of an incretin-sodium-glucose cotransporter 2 inhibitor or glucagon-like peptide-1 agonist-basal insulin hold promise to achieve robust glycemic control with weight loss and low risk for hypoglycemia.

  12. Impact of pressure recovery on echocardiographic assessment of asymptomatic aortic stenosis: a SEAS substudy

    DEFF Research Database (Denmark)

    Bahlmann, Edda; Cramariuc, Dana; Gerdts, Eva

    2010-01-01

    The aim of this analysis was to assess the diagnostic importance of pressure recovery in evaluation of aortic stenosis (AS) severity.......The aim of this analysis was to assess the diagnostic importance of pressure recovery in evaluation of aortic stenosis (AS) severity....

  13. Hydrodynamic pressure processing: Impact on the quality attributes of fresh and further-processed meat products

    Science.gov (United States)

    This book chapter reviews hydrodynamic pressure processing (HDP) as an innovative, postharvest technology for enhancing the quality attributes of fresh and further-processed meat products. A variety of meat products have been tested for their response to the high pressure shockwaves of HDP. The st...

  14. Evidence of current impact of climate change on life: a walk from genes to the biosphere.

    Science.gov (United States)

    Peñuelas, Josep; Sardans, Jordi; Estiarte, Marc; Ogaya, Romà; Carnicer, Jofre; Coll, Marta; Barbeta, Adria; Rivas-Ubach, Albert; Llusià, Joan; Garbulsky, Martin; Filella, Iolanda; Jump, Alistair S

    2013-08-01

    We review the evidence of how organisms and populations are currently responding to climate change through phenotypic plasticity, genotypic evolution, changes in distribution and, in some cases, local extinction. Organisms alter their gene expression and metabolism to increase the concentrations of several antistress compounds and to change their physiology, phenology, growth and reproduction in response to climate change. Rapid adaptation and microevolution occur at the population level. Together with these phenotypic and genotypic adaptations, the movement of organisms and the turnover of populations can lead to migration toward habitats with better conditions unless hindered by barriers. Both migration and local extinction of populations have occurred. However, many unknowns for all these processes remain. The roles of phenotypic plasticity and genotypic evolution and their possible trade-offs and links with population structure warrant further research. The application of omic techniques to ecological studies will greatly favor this research. It remains poorly understood how climate change will result in asymmetrical responses of species and how it will interact with other increasing global impacts, such as N eutrophication, changes in environmental N : P ratios and species invasion, among many others. The biogeochemical and biophysical feedbacks on climate of all these changes in vegetation are also poorly understood. We here review the evidence of responses to climate change and discuss the perspectives for increasing our knowledge of the interactions between climate change and life.

  15. The current economic situation in China and its impact on the Czech Republic

    Directory of Open Access Journals (Sweden)

    Hana Stverkova

    2016-03-01

    Full Text Available Nowadays, many companies try to enter to the international sector and to extend here their activity. Their international cooperation is an integral part of the action; it is necessary to know the cultural differences. Therefore it is important to understand the social development including the Social Progress Index and the secondary analysis of an economic situation in China; and its subsequent impact on the economy not only in the Czech Republic based on evaluation of Czech-Chinese business relations. China was in the last five years the male rotor of the world economic growth and became a significant importer of commodities. Last year, the Chinese economic growth rate slowed down, which could have negative consequences on other economies. This is also the possible reason for some Czech companies leaving the Chinese market; they transfer their production parts back to Europe or India. A presumption of high living standard, which all countries of the world and their inhabitants want to achieve, is according to the current paradigm of economic science the economic growth. The economy does not take pace in a vertical line, but at the horizontal level as the meaning of sharing in the net among the individuals. And the cooperation does not take place in the horizontal line but in the vertical line, which essentially changes the way of people's working.

  16. Fibrosis assessment: impact on current management of chronic liver disease and application of quantitative invasive tools.

    Science.gov (United States)

    Wang, Yan; Hou, Jin-Lin

    2016-05-01

    Fibrosis, a common pathogenic pathway of chronic liver disease (CLD), has long been indicated to be significantly and most importantly associated with severe prognosis. Nowadays, with remarkable advances in understanding and/or treatment of major CLDs such as hepatitis C, B, and nonalcoholic fatty liver disease, there is an unprecedented requirement for the diagnosis and assessment of liver fibrosis or cirrhosis in various clinical settings. Among the available approaches, liver biopsy remains the one which possibly provides the most direct and reliable information regarding fibrosis patterns and changes in the parenchyma at different clinical stages and with different etiologies. Thus, many endeavors have been undertaken for developing methodologies based on the strategy of quantitation for the invasive assessment. Here, we analyze the impact of fibrosis assessment on the CLD patient care based on the data of recent clinical studies. We discuss and update the current invasive tools regarding their technological features and potentials for the particular clinical applications. Furthermore, we propose the potential resolutions with application of quantitative invasive tools for some major issues in fibrosis assessment, which appear to be obstacles against the nowadays rapid progress in CLD medicine.

  17. Current Progresses in Study of Impacts of the Tibetan Plateau on Asian Summer Climate

    Institute of Scientific and Technical Information of China (English)

    WU Guoxiong; MAO Jiangyu; DUAN Anmin; ZHANG Qiong

    2006-01-01

    The current progresses in the study of impacts of the Tibetan Plateau on Asian summer climate in the last decade are reviewed. By analyzing evolution of the transitional zone between westerly to the north and easterly to the south (WEB), it is shown that due to the strong heating over the Tibetan Plateau in spring, the overturning in the prevailing wind direction from easterly in winter to westerly in summer occurs firstly over the eastern Bay of Bengal (BOB), accompanied with vigorous convective precipitation to its east. The area between eastern BOB and western Indo-China Peninsula thus becomes the area with the earliest onset of Asian monsoon, which may be referred as BOB monsoon in short. It is shown that the summertime circulations triggered by the thermal forcing of the Iranian Plateau and the Tibetan Plateau are embedded in phase with the continental-scale circulation forced by the diabatic heating over the Eurasian Continent. As a result, the East Asian summer monsoon is intensified and the drought climate over the western and central Asian areas is enhanced. Together with perturbations triggered by the Tibetan Plateau,the above scenarios and the associated heating have important influences on the climate patterns over Asia.Furthermore, the characteristics of the Tibetan mode of the summertime South Asian high are compared with those of Iranian mode. Results demonstrate that corresponding to each of the bimodality of the South Asian high, the rainfall anomaly distributions over Asia exhibit different patterns.

  18. The formation, properties and impact of secondary organic aerosol: current and emerging issues

    Directory of Open Access Journals (Sweden)

    M. Hallquist

    2009-02-01

    Full Text Available Secondary organic aerosol (SOA accounts for a significant fraction of ambient tropospheric aerosol and a detailed knowledge of the formation, properties and transformation of SOA is therefore required to evaluate its impact on atmospheric processes, climate and human health. The chemical and physical processes associated with SOA formation are complex and varied, and, despite considerable progress in recent years, a quantitative and predictive understanding of SOA formation does not exist and therefore represents a major research challenge in atmospheric science. This review begins with a description of the current state of knowledge on the global SOA budget and the atmospheric degradation mechanisms for SOA precursors. The topic of gas-particle partitioning theory is followed by an account of the analytical techniques used to determine the chemical composition of SOA. A survey of recent laboratory, field and modeling studies is also presented. The following topical and emerging issues are highlighted and discussed in detail; molecular characterization of biogenic SOA constituents, condensed phase reactions and oligomerization, the interaction of atmospheric organic components with sulfuric acid, the chemical and photochemical processing of organics in the atmospheric aqueous phase, aerosol formation from real plant emissions, interaction of atmospheric organic components with water, thermodynamics and mixtures in atmospheric models. Finally, the major challenges ahead in laboratory, field and modeling studies of SOA are discussed and recommendations for future research directions are proposed.

  19. The formation, properties and impact of secondary organic aerosol: current and emerging issues

    Directory of Open Access Journals (Sweden)

    J. Wildt

    2009-07-01

    Full Text Available Secondary organic aerosol (SOA accounts for a significant fraction of ambient tropospheric aerosol and a detailed knowledge of the formation, properties and transformation of SOA is therefore required to evaluate its impact on atmospheric processes, climate and human health. The chemical and physical processes associated with SOA formation are complex and varied, and, despite considerable progress in recent years, a quantitative and predictive understanding of SOA formation does not exist and therefore represents a major research challenge in atmospheric science. This review begins with an update on the current state of knowledge on the global SOA budget and is followed by an overview of the atmospheric degradation mechanisms for SOA precursors, gas-particle partitioning theory and the analytical techniques used to determine the chemical composition of SOA. A survey of recent laboratory, field and modeling studies is also presented. The following topical and emerging issues are highlighted and discussed in detail: molecular characterization of biogenic SOA constituents, condensed phase reactions and oligomerization, the interaction of atmospheric organic components with sulfuric acid, the chemical and photochemical processing of organics in the atmospheric aqueous phase, aerosol formation from real plant emissions, interaction of atmospheric organic components with water, thermodynamics and mixtures in atmospheric models. Finally, the major challenges ahead in laboratory, field and modeling studies of SOA are discussed and recommendations for future research directions are proposed.

  20. LightForce Photon-pressure Collision Avoidance: Efficiency Analysis in the Current Debris Environment and Long-Term Simulation Perspective

    Science.gov (United States)

    Yang, Fan Y.; Nelson, Bron; Carlino, Roberto; Perez, Andres D.; Faber, Nicolas; Henze, Chris; Karacahoglu, Arif G.; O'Toole, Conor; Swenson, Jason; Stupl, Jan

    2015-01-01

    This work provides an efficiency analysis of the LightForce space debris collision avoidance scheme in the current debris environment and describes a simulation approach to assess its impact on the long-term evolution of the space debris environment. LightForce aims to provide just-in-time collision avoidance by utilizing photon pressure from ground-based industrial lasers. These ground stations impart minimal accelerations to increase the miss distance for a predicted conjunction between two objects. In the first part of this paper we will present research that investigates the short-term effect of a few systems consisting of 10kW class lasers directed by 1.5 m diameter telescopes using adaptive optics. The results found such a network of ground stations to mitigate more than 85 percent of conjunctions and could lower the expected number of collisions in Low Earth Orbit (LEO) by an order of magnitude. While these are impressive numbers that indicate LightForce's utility in the short-term, the remaining 15 percent of possible collisions contain (among others) conjunctions between two massive objects that would add large amount of debris if they collide. Still, conjunctions between massive objects and smaller objects can be mitigated. Hence we choose to expand the capabilities of the simulation software to investigate the overall effect of a network of LightForce stations on the long-term debris evolution. In the second part of this paper, we will present the planed simulation approach for that effort.

  1. Two-phase flow experiments on Counter-Current Flow Limitation in a model of the hot leg of a pressurized water reactor (2015 test series)

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Matthias; Lucas, Dirk; Pietruske, Heiko; Szalinski, Lutz

    2016-12-15

    Counter-Current Flow Limitation (CCFL) is of importance for PWR safety analyses in several accident scenarios connected with loss of coolant. Basing on the experiences obtained during a first series of hot leg tests now new experiments on counter-current flow limitation were conducted in the TOPFLOW pressure vessel. The test series comprises air-water tests at 1 and 2 bar as well as steam-water tests at 10, 25 and 50 bar. During the experiments the flow structure was observed along the hot leg model using a high-speed camera and web-cams. In addition pressure was measured at several positions along the horizontal part and the water levels in the reactor-simulator and steam-generator-simulator tanks were determined. This report documents the experimental setup including the description of operational and special measuring techniques, the experimental procedure and the data obtained. From these data flooding curves were obtained basing on the Wallis parameter. The results show a slight shift of the curves in dependency of the pressure. In addition a slight decrease of the slope was found with increasing pressure. Additional investigations concern the effects of hysteresis and the frequencies of liquid slugs. The latter ones show a dependency on pressure and the mass flow rate of the injected water. The data are available for CFD-model development and validation.

  2. Long-term impact of systolic blood pressure and glycemia on the development of microalbuminuria in essential hypertension.

    Science.gov (United States)

    Pascual, Jose Maria; Rodilla, Enrique; Gonzalez, Carmen; Pérez-Hoyos, Santiago; Redon, Josep

    2005-06-01

    The objective was to assess the temporal impact of factors related to the development of microalbuminuria during the follow-up of young adult normoalbuminurics with high-normal blood pressure or at stage 1 of essential hypertension. Prospective follow-up was conducted on 245 normoalbuminuric hypertensive subjects (mean age 40.9 years; 134 men; blood pressure 139.7/88.6 mm Hg; body mass index 28.5 kg/m2) never treated previously with antihypertensive drugs, with yearly urinary albumin excretion measurements, until the development of microalbuminuria. After enrollment, patients were placed on usual care including nonpharmacological treatment or with an antihypertensive drug regime to achieve a blood pressure of 15 mg per 24-hour systolic blood pressure >139 mm Hg and a positive trend in fasting glucose were observed in the univariate analyses. However, in the multivariate analysis, only the baseline urinary albumin excretion and the trend of fasting glucose were independently related to the risk of developing microalbuminuria. In mild hypertensives, the development of microalbuminuria was linked to insufficient blood pressure control and to a progressive increment of glucose values.

  3. Pressure tube creep impact on the physics parameters for CANDU-6 reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, W. Y.; Min, B. J. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kam, S. C.; Kim, M. E. [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    2004-07-01

    The lattice cell calculations are performed to assess the sensitivity of the reactor physics parameters to pressure tube creep resulting from radiation aging. The physics parameters of the lattice cell are calculated by using WIMSD-5B code, WIMS- AECL code, and MCNP code. The reference model(normal state) and two perturbed models accounting for the pressure tube creep are developed on the basis of CANDU-6 lattice cell. The 2.5% and 5% values of pressure tube diameter creep are considered. Also, The effects of the analyzed lattice parameters which are the coolant void reactivity, the fuel fission density and the atom density of Pu isotopes on the lattice.

  4. Physical, chemical, current profile, water pressure, sea surface temperature, meteorological, and other data from current meters, bottle casts, pressure gauges, meteorological sensors, current meters, and other instruments from the ANDRE NIZERY and other platforms from the TOGA Area - Atlantic as part of the Seasonal Response of the Equatorial Atlantic Experiment/Francais Ocean Et Climat Dans L'Atlantique Equatorial (SEQUAL/FOCAL) project from 01 January 1964 to 31 December 1985 (NODC Accession 8700150)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, chemical, current profile, water pressure, sea surface temperature, meteorological, and other data were collected from the ANDRE NIZERY and other platforms...

  5. Influence of oxygen pressure on critical current density and magnetic flux pinning structures in YBa2Cu3O7-x fabricated by chemical solution deposition

    Institute of Scientific and Technical Information of China (English)

    Ding Fa-Zhu; Gu Hong-Wei; Zhang Teng; Dai Shao-Tao; Xiao Li-Ye

    2011-01-01

    This paper studies the effect of oxygen partial pressure on the fabrication of YBa2Cu3O7-x films on (00/) LaAlO3 substrates by metalorganic deposition using trifluoroacetates (TFA-MOD). As the oxygen partial pressure increases to 1500 Pa, a great increase in the superconducting properties is observed at high magnetic fields parallel to the YBCO c axis. The cross-sectional transmission electron microscope images show that a high density of stacking faults in the size range of 10-15 nm may act as flux pinning centres to enhance the critical current density of the YBCO films

  6. Impact of shamal winds and swells on the coastal currents along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Samiksha, S.V.; VinodKumar, K.; Vethamony, P.

    , the de-tided current data present a distinct change in the current direction and increase in current speeds (approximately from 0.08 m/s to 0.15 m/s) It can be inferred from the analysis that the waves which propagate from NW and the currents which flow...

  7. The Impact of Age on the Ability to Perform under Pressure: Golfers on the PGA Tour

    OpenAIRE

    Harold O. FRIED; Tauer, Loren W.

    2009-01-01

    This paper is about aging and the ability to perform under pressure on the PGA tour. Performance increases with golfing skill, but may first increase and then decrease with age as experience interacts with changes in physical condition. Similarly, mental fortitude or the ability of a golfer to perform under pressure may first increase and then decrease with age as experience interacts with changes in the ability to concentrate. Net performance on the tour is the result of both physical golfin...

  8. Impact of financial pressure on unemployed job search, job find success and job quality

    OpenAIRE

    Gerards, Ruud; Welters, Ricardo

    2016-01-01

    Research shows that financial pressure – implied as a consequence of benefit sanctions or exhaustion – prompts the unemployed to intensify their job search. However, there is less agreement about whether that intensified job search produces better quality job outcomes. Building on Self-Determination Theory we posit that financial pressure is a controlled motivator to search for work. Controlled motivators are conducive to goal pursuit (job search activity), yet unfavorable to goal achievement...

  9. Impact of Colonization Pressure and Strain Type on Methicillin-Resistant Staphylococcus aureus Transmission in Children

    OpenAIRE

    Popoola, Victor O.; Carroll, Karen C.; Ross, Tracy; Reich, Nicholas G.; Perl, Trish M; Milstone, Aaron M.

    2013-01-01

    We studied the transmissibility of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and healthcare-associated methicillin-resistant S. aureus (HA-MRSA) strains and the association of MRSA colonization pressure and MRSA transmission in critically ill children. Importantly, we found that in hospitalized children MRSA colonization pressure above 10% increases the risk of MRSA transmission 3-fold, and CA-MRSA and HA-MRSA strains have similar transmission dynamics.

  10. The impact of parental pressure on the performance of high school track athletes

    OpenAIRE

    2012-01-01

    M.A. This study was conducted to ascertain whether there is a significant relationship between, parental pressure, stress levels and athletic performance in high school track and field athletes. The question can be asked whether parental pressure will result in increased stress levels in the athlete and therefore poorer performance? Sixty-six high school track and field athletes, between the ages of 13 and 18 years, were selected for the study. The athletes were taken from training groups ...

  11. Open access to journal articles in oncology: current situation and citation impact.

    Science.gov (United States)

    Hua, F; Sun, H; Walsh, T; Glenny, A-M; Worthington, H

    2017-10-01

    Recent years have seen numerous efforts and resources devoted to the development of open access (OA), but the current OA situation of the oncology literature remains unknown. We conducted this cross-sectional study to determine the current share and provision methods of OA in the field of oncology, identify predictors of OA status (OA versus non-OA), and study the association between OA and citation counts. PubMed was searched for oncology-related, peer-reviewed journal articles published in December 2014. Google, Google Scholar, PubMed, ResearchGate, OpenDOAR and OAIster were manually checked to assess the OA status of each included article. Citation data were extracted from Web of Science, Scopus and Google Scholar. Descriptive statistics were used to summarize the OA proportion (primary outcome) and OA provision methods. Multivariable logistic regression and multilevel generalized linear model analyses were performed to study predictors of OA status and the association between OA and citation counts, respectively. In a random sample of 1000 articles, 912 were deemed eligible and therefore included. Of these, the full-texts of 530 articles (58.1%; 95% CI: 54.9-61.3) were freely available online: 314 (34.4%) were available from publishers ('Gold road' to OA), 424 (46.5%) were available via self-archiving ('Green road' to OA). According to multivariable regression analyses, impact factor, publisher type, language, research type, number of authors, continent of origin, and country income were significant predictors of articles' OA status; OA articles received a citation rate 1.24 times the incidence rate for non-OA articles (95% CI: 1.05-1.47; P = 0.012). Based on our sample, in the field of oncology, 42% of recent journal articles are behind the pay-wall (non-OA) 1 year after publication; the 'Green road' of providing OA is more common than the 'Gold road'; OA is associated with higher citation counts.

  12. Impact of education on obesity and blood pressure in developing countries: A study on the Ibos of Nigeria

    Directory of Open Access Journals (Sweden)

    Godson Emeka Anyanwu

    2010-01-01

    Full Text Available Background: Increase in the prevalence of hypertension, obesity and obesity related diseases has become significant cause of disability and premature death in both developing and newly developed countries, with over bearing demand on national health budgets. Aim: To evaluate the impact of various levels of education on obesity and blood pressure . Materials and Method : 325 male and 254 female Nigerians of ages 20-80 years of the Ibo ethnicity through random sampling, were selected for this study. The participants were broken into three major groups based on their educational levels; primary, secondary and tertiary levels. systolic and diastolic blood pressure (SBP & DBP levels, body mass index (BMI, waist hip ratio (WHR, waist height ratio (WHtR, waist circumference (WC,various skin fold thicknesses, and other anthropometric parameters were measured. Result: For all the indicators of subcutaneous fat, general obesity, and central obesity, largest mean deposition was noted to be highest in the lowest education group and least in the highest education group. Mean blood pressure parameters were also highest in the least education group. While fat deposition was noted to be highest in all the females of all the groups, the males showed larger mean BP values. Education was noted to have a significant inverse relationship with most of the fat indicators and blood pressure parameters and cardiovascular disease risk highest in the least education groups. Conclusion: Education showed a significant impact on obesity and blood pressure and could be one of the major tools to reduce the high prevalence of obesity, hypertension and other obesity associated diseases.

  13. Impact of education on obesity and blood pressure in developing countries: A study on the Ibos of Nigeria

    Directory of Open Access Journals (Sweden)

    Godson Emeka Anyanwu

    2010-07-01

    Full Text Available Background: Increase in the prevalence of hypertension, obesity and obesity related diseases has become significant cause of disability and premature death in both developing and newly developed countries, with over bearing demand on national health budgets. Aim: To evaluate the impact of various levels of education on obesity and blood pressure. Materials and Method :325 male and 254 female Nigerians of ages 20-80 years of the Ibo ethnicity through random sampling, were selected for this study. The participants were broken into three major groups based on their educational levels; primary, secondary and tertiary levels. systolic and diastolic blood pressure (SBP & DBP levels, body mass index (BMI, waist hip ratio (WHR, waist height ratio (WHtR, waist circumference (WC,various skin fold thicknesses, and other anthropometric parameters were measured. Result: For all the indicators of subcutaneous fat, general obesity, and central obesity, largest mean deposition was noted to be highest in the lowest education group and least in the highest education group. Mean blood pressure parameters were also highest in the least education group. While fat deposition was noted to be highest in all the females of all the groups, the males showed larger mean BP values. Education was noted to have a significant inverse relationship with most of the fat indicators and blood pressure parameters and cardiovascular disease risk highest in the least education groups. Conclusion: Education showed a significant impact on obesity and blood pressure and could be one of the major tools to reduce the high prevalence of obesity, hypertension and other obesity associated diseases.

  14. Impact of a board-game approach on current smokers: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Khazaal Yasser

    2013-01-01

    Full Text Available Abstract Background The main objective of our study was to assess the impact of a board game on smoking status and smoking-related variables in current smokers. To accomplish this objective, we conducted a randomized controlled trial comparing the game group with a psychoeducation group and a waiting-list control group. Methods The following measures were performed at participant inclusion, as well as after a 2-week and a 3-month follow-up period: “Attitudes Towards Smoking Scale” (ATS-18, “Smoking Self-Efficacy Questionnaire” (SEQ-12, “Attitudes Towards Nicotine Replacement Therapy” scale (ANRT-12, number of cigarettes smoked per day, stages of change, quit attempts, and smoking status. Furthermore, participants were assessed for concurrent psychiatric disorders and for the severity of nicotine dependence with the Fagerström Test for Nicotine Dependence (FTND. Results A time × group effect was observed for subscales of the ANRT-12, ATS-18 and SEQ-12, as well as for the number of cigarettes smoked per day. At three months follow-up, compared to the participants allocated to the waiting list group, those on Pick-Klop group were less likely to remain smoker. Outcomes at 3 months were not predicted by gender, age, FTND, stage of change, or psychiatric disorders at inclusion. Conclusions The board game seems to be a good option for smokers. The game led to improvements in variables known to predict quitting in smokers. Furthermore, it increased smoking-cessation rates at 3-months follow-up. The game is also an interesting alternative for smokers in the precontemplation stage.

  15. Impact of a board-game approach on current smokers: a randomized controlled trial.

    Science.gov (United States)

    Khazaal, Yasser; Chatton, Anne; Prezzemolo, Roberto; Zebouni, Fadi; Edel, Yves; Jacquet, Johan; Ruggeri, Ornella; Burnens, Emilie; Monney, Grégoire; Protti, Anne-Sylvie; Etter, Jean-François; Khan, Riaz; Cornuz, Jacques; Zullino, Daniele

    2013-01-17

    The main objective of our study was to assess the impact of a board game on smoking status and smoking-related variables in current smokers. To accomplish this objective, we conducted a randomized controlled trial comparing the game group with a psychoeducation group and a waiting-list control group. The following measures were performed at participant inclusion, as well as after a 2-week and a 3-month follow-up period: "Attitudes Towards Smoking Scale" (ATS-18), "Smoking Self-Efficacy Questionnaire" (SEQ-12), "Attitudes Towards Nicotine Replacement Therapy" scale (ANRT-12), number of cigarettes smoked per day, stages of change, quit attempts, and smoking status. Furthermore, participants were assessed for concurrent psychiatric disorders and for the severity of nicotine dependence with the Fagerström Test for Nicotine Dependence (FTND). A time × group effect was observed for subscales of the ANRT-12, ATS-18 and SEQ-12, as well as for the number of cigarettes smoked per day. At three months follow-up, compared to the participants allocated to the waiting list group, those on Pick-Klop group were less likely to remain smoker.Outcomes at 3 months were not predicted by gender, age, FTND, stage of change, or psychiatric disorders at inclusion. The board game seems to be a good option for smokers. The game led to improvements in variables known to predict quitting in smokers. Furthermore, it increased smoking-cessation rates at 3-months follow-up. The game is also an interesting alternative for smokers in the precontemplation stage.

  16. Impact of current cough on health-related quality of life in patients with COPD

    Science.gov (United States)

    Deslee, Gaëtan; Burgel, Pierre-Régis; Escamilla, Roger; Chanez, Pascal; Court-Fortune, Isabelle; Nesme-Meyer, Pascale; Brinchault-Rabin, Graziella; Perez, Thierry; Jebrak, Gilles; Caillaud, Denis; Paillasseur, Jean-Louis; Roche, Nicolas

    2016-01-01

    Background Cough and sputum production are frequent in chronic obstructive pulmonary disease (COPD). The objective of this study was to examine the relationship between cough and sputum production and health-related quality of life in COPD. Methods A cross-sectional study was conducted in the French Initiatives COPD cohort and assessed cough and sputum production within the past 7 days using the cough and sputum assessment questionnaire (CASA-Q), health-related quality of life, spirometry, smoking status, dyspnea, exacerbations, anxiety and depression, and comorbidities. Results One hundred and seventy-eight stable COPD patients were included (age, 62 [56–69] years, 128 male, forced expiratory volume in 1 second [FEV1]: 57 [37–72] % predicted) (median [Q1–Q3]). In univariate analyses, health-related quality of life (Saint George’s respiratory questionnaire total score) was associated with each CASA-Q domain and with chronic bronchitis, exacerbations, dyspnea, FEV1, depression, and anxiety. All four domains introduced separately were independently associated with health-related quality of life. When introduced together in multivariate analyses, only the cough impact domain remained independently associated with health-related quality of life (R2=0.60). With chronic bronchitis (standard definition) instead of the CASA-Q, the R2 was lower (R2=0.54). Conclusion This study provides evidence that current cough in the previous 7 days is an important determinant of health-related quality of life impairment in stable COPD patients. PMID:27695305

  17. Current infant feeding practices and impact on growth in babies during the second half of infancy.

    Science.gov (United States)

    Bandara, T; Hettiarachchi, M; Liyanage, C; Amarasena, S

    2015-08-01

    Sri Lanka has made remarkable improvements in health, social and educational indices. However, child malnutrition exists as a significant health problem. Infant feeding indicators have not reached expected levels and improvements are partly constrained by a lack of data. The present study aimed to determine current infant feeding practices and their impact on growth among 6-12-month-old infants. The study comprised a descriptive cross-sectional investigation conducted in randomly selected (n = 7) Public Health Midwife areas in Galle, Sri Lanka. An interviewer-administered questionnaire was used to obtain data on sociodemographics and infant feeding. Mothers (n = 515) attending well-baby clinics were recruited on voluntary and consecutive basis. Infants' body weights and lengths were measured using standard procedures. Exclusive breastfeeding rate for first 6 months was 49.0%. In total, 42.6% infants (219 out of 515) were given rice as first weaning food, followed by salt (58.6%) and sugar (42.3%). Oil had been introduced to 84.9% of infants by the end of 12 months. Most infants (over 71%) were given dairy products, whereas 62.3% were being fed various liquid foods using bottles. The introduction of commercial infant cereals, chocolates, plain tea, ice cream and deep fried snacks was noted. Age-specific body weight and length were not achieved by 30.5% and 29.5% of infants, respectively. Weight for length was not achieved by 25.5% of the infants. Delayed achievements of motor milestones were observed. Mothers' knowledge scores on basic nutrients were low. Complementary feeding indices of the study group were not satisfactory. Maternal and child healthcare personnel need to identify causative factors for inappropriate feeding with a view to improve the complementary feeding patterns. © 2014 The British Dietetic Association Ltd.

  18. LightForce photon-pressure collision avoidance: Efficiency analysis in the current debris environment and long-term simulation perspective

    Science.gov (United States)

    Yang Yang, Fan; Nelson, Bron; Aziz, Jonathan; Carlino, Roberto; Dono Perez, Andres; Faber, Nicolas; Foster, Cyrus; Frost, Chad; Henze, Chris; Karacalıoğlu, Arif Göktuğ; Levit, Creon; Marshall, William; Mason, James; O'Toole, Conor; Swenson, Jason; Worden, Simon P.; Stupl, Jan

    2016-09-01

    This work provides an efficiency analysis of the LightForce space debris collision avoidance scheme in the current debris environment and describes a simulation approach to assess its impact on the long-term evolution of the space debris environment. LightForce aims to provide just-in-time collision avoidance by utilizing photon pressure from ground-based industrial lasers. These ground stations impart minimal accelerations to increase the miss distance for a predicted conjunction between two objects. In the first part of this paper we will present research that investigates the short-term effect of a few systems consisting of 20 kW class lasers directed by 1.5 m diameter telescopes using adaptive optics. The results found such a network of ground stations to mitigate more than 85 percent of conjunctions and could lower the expected number of collisions in Low Earth Orbit (LEO) by an order of magnitude. While these are impressive numbers that indicate LightForce's utility in the short-term, the remaining 15 % of possible collisions contain (among others) conjunctions between two massive objects that would add large amount of debris if they collide. Still, conjunctions between massive objects and smaller objects can be mitigated. Hence, we choose to expand the capabilities of the simulation software to investigate the overall effect of a network of LightForce stations on the long-term debris evolution. In the second part of this paper, we will present the planned simulation approach for that effort. For the efficiency analysis of collision avoidance in the current debris environment, we utilize a simulation approach that uses the entire Two Line Element (TLE) catalog in LEO for a given day as initial input. These objects are propagated for one year and an all-on-all conjunction analysis is performed. For conjunctions that fall below a range threshold, we calculate the probability of collision and record those values. To assess efficiency, we compare a baseline

  19. Impact of gonadectomy on blood pressure regulation in ageing male and female rats.

    Science.gov (United States)

    Pijacka, Wioletta; Clifford, Bethan; Walas, Dawid; Tilburgs, Chantal; Joles, Jaap A; McMullen, Sarah; Langley-Evans, Simon C

    2016-01-01

    Sexual dimorphism in blood pressure has been associated with differential expression of the angiotensin II (AII) receptors and with activity of the nervous system. It is generally accepted that ageing affects kidney function as well as autonomic nervous system and hormonal balance. Given that hypertension is more prevalent in men than women until women reach their seventh decade, we hypothesised that females would be relatively protected from adverse effects of ageing compared to males and that this would be mediated by the protective effect of ovarian steroids. Intact and gonadectomised male and female normotensive Wistar rats aged 6, 12 and 18 months were used to study renal function, blood pressure, heart rate, and blood pressure variability. We observed that intact females had lower levels of proteinuria and higher (12.5%) creatinine clearance compared to intact males and that this difference was abolished by castration but not by ovariectomy. Ovariectomy resulted in a change by 9% in heart rate, resulting in similar cardiovascular parameters to those observed in males or gonadectomised males. Spectral analysis of systolic blood pressure revealed that high-frequency power spectra were significantly elevated in the females vs. males and were reduced by ovariectomy. Taken altogether, the results show that females are protected from age-related declining renal function and to a lesser extent from rising blood pressure in comparison to males. Whilst ovariectomy had some deleterious effects in females, the strongest effects were associated with gonadectomy in males, suggesting a damaging effect of male hormones.

  20. Impact of sample geometry on the measurement of pressure-saturation curves: experiments and simulations

    CERN Document Server

    Moura, M; Måløy, Knut Jørgen; Schäfer, G; Toussaint, R

    2015-01-01

    In this paper we study the influence of sample geometry on the measurement of pressure-saturation relationships, by analyzing the drainage of a two-phase flow from a quasi-2D random porous medium. The medium is transparent, which allows for the direct visualization of the invasion pattern during flow, and is initially saturated with a viscous liquid (a dyed glycerol-water mix). As the pressure in the liquid is gradually reduced, air penetrates from an open inlet, displacing the liquid which leaves the system from an outlet on the opposite side. Pressure measurements and images of the flow are recorded and the pressure-saturation relationship is computed. We show that this relationship depends on the system size and aspect ratio. The effects of the system's boundaries on this relationship are measured experimentally and compared with simulations produced using an invasion percolation algorithm. The pressure build up at the beginning and end of the invasion process are particularly affected by the boundaries of...

  1. Impact of the postpump resistance on pressure-flow waveform and hemodynamic energy level in a neonatal pulsatile centrifugal pump.

    Science.gov (United States)

    Wang, Shigang; Haines, Nikkole; Richardson, J Scott; Dasse, Kurt A; Undar, Akif

    2009-01-01

    This study tested the impact of different postpump resistances on pulsatile pressure-flow waveforms and hemodynamic energy output in a mock extracorporeal system. The circuit was primed with a 40% glycerin-water mixture, and a PediVAS centrifugal pump was used. The pre- and postpump pressures and flow rates were monitored via a data acquisition system. The postpump resistance was adjusted using a Hoffman clamp at the outlet of the pump. Five different postpump resistances and rotational speeds were tested with nonpulsatile (NP: 5000 RPM) and pulsatile (P: 4000 RPM) modes. No backflow was found when using pulsatile flow. With isoresistance, increased arterial resistances decreased pump flow rates (NP: from 1,912 ml/min to 373 ml/min; P: from 1,485 ml/min to 288 ml/min), increased postpump pressures (NP: from 333 mm Hg to 402 mm Hg; P: from 223 mm Hg to 274 mm Hg), and increased hemodynamic energy output with pulsatile mode. Pump flow rate correlated linearly with rotational speed (RPMs) of the pump, whereas postpump pressures and hemodynamic energy outputs showed curvilinear relationships with RPMs. The maximal pump flow rate also increased from 618 ml/min to 4,293 ml/min with pulsatile mode and from 581 ml/min to 5,665 ml/min with nonpulsatile mode. Results showed that higher postpump resistance reduced the pump flow range, and increased postpump pressure and surplus hemodynamic energy output with pulsatile mode. Higher rotational speeds also generated higher pump flow rates, postpump pressures, and increased pulsatility.

  2. Differential impact of belatacept and cyclosporine A on central aortic blood pressure and arterial stiffness after renal transplantation.

    Science.gov (United States)

    Seibert, Felix S; Steltzer, Julia; Melilli, Eduardo; Grannas, Gerrit; Pagonas, Nikolaos; Bauer, Frederic; Zidek, Walter; Grinyó, Josep; Westhoff, Timm H

    2014-09-01

    Calcineurin inhibitors (CNI) are potent vasoconstrictors and induce an acceleration of arteriosclerosis, thus contributing to the cardiovascular risk after renal transplantation. The study compares the impact of belatacept and cyclosporine A (CsA) on arterial stiffness and central aortic blood pressure. We performed a case-control study in 46 patients (23 on belatacept and 23 on CsA) matched for age, body mass index, time after transplantation, and time on dialysis prior to transplantation. Pulse wave analysis (SphygmoCor, AtCor(®) ) was used to assess central aortic blood pressure, aortic augmentation pressure, and pulse wave velocity (PWV) as a marker of arterial stiffness. Assessment of vascular function was performed after a minimum of 20 months and a median follow-up of 81 months post-transplant. Peripheral systolic and diastolic blood pressure did not significantly differ in the two groups (p > 0.05 each). The central aortic augmentation pressure was higher in the CsA group (12.7 mmHg vs. 7.3 mmHg, p = 0.048). PWV as a measure of arterial stiffness did not differ in the two groups. Thus, belatacept is not associated with a significant difference in arterial stiffness compared to CsA after a median of 81 months post-transplant. It is associated, however, with a lower aortic augmentation pressure, a strong independent cardiovascular risk factor. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Shared Solar: Current Landscape, Market Potential, and the Impact of Federal Securities Regulation; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-05-27

    This presentation provides a high-level overview of the current U.S. shared solar landscape, the impact that a given shared solar program's structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.

  4. The Impact of Sarcopenia on Survival and Complications in Surgical Oncology: A Review of the Current Literature

    Science.gov (United States)

    JOGLEKAR, SAVITA; NAU, PETER N.; MEZHIR, JAMES J.

    2016-01-01

    Sarcopenia is the subclinical loss of skeletal muscle and strength and has been extensively studied in both the cancer and surgical literature. Specifically, sarcopenia has gained significant recognition as an important prognostic factor for both complications and survival in cancer patients. Herein, we review the current literature to date highlighting the specific impact of sarcopenia in patients undergoing oncologic procedures. PMID:26310812

  5. The impact of sarcopenia on survival and complications in surgical oncology: A review of the current literature.

    Science.gov (United States)

    Joglekar, Savita; Nau, Peter N; Mezhir, James J

    2015-10-01

    Sarcopenia is the subclinical loss of skeletal muscle and strength and has been extensively studied in both the cancer and surgical literature. Specifically, sarcopenia has gained significant recognition as an important prognostic factor for both complications and survival in cancer patients. Herein, we review the current literature to date highlighting the specific impact of sarcopenia in patients undergoing oncologic procedures.

  6. Impact of urban WWTP and CSO fluxes on river peak flow extremes under current and future climate conditions.

    Science.gov (United States)

    Keupers, Ingrid; Willems, Patrick

    2013-01-01

    The impact of urban water fluxes on the river system outflow of the Grote Nete catchment (Belgium) was studied. First the impact of the Waste Water Treatment Plant (WWTP) and the Combined Sewer Overflow (CSO) outflows on the river system for the current climatic conditions was determined by simulating the urban fluxes as point sources in a detailed, hydrodynamic river model. Comparison was made of the simulation results on peak flow extremes with and without the urban point sources. In a second step, the impact of climate change scenarios on the urban fluxes and the consequent impacts on the river flow extremes were studied. It is shown that the change in the 10-year return period hourly peak flow discharge due to climate change (-14% to +45%) was in the same order of magnitude as the change due to the urban fluxes (+5%) in current climate conditions. Different climate change scenarios do not change the impact of the urban fluxes much except for the climate scenario that involves a strong increase in rainfall extremes in summer. This scenario leads to a strong increase of the impact of the urban fluxes on the river system.

  7. Continuous cuff-less blood pressure monitoring based on the pulse arrival time approach: the impact of posture.

    Science.gov (United States)

    Muehlsteff, J; Aubert, X A; Morren, G

    2008-01-01

    There is an unmet need for cuff-less blood pressure (BP) monitoring especially, in personal healthcare applications. The pulse arrival time (PAT) approach might offer a suitable solution to enable comfortable BP monitoring even at beat-level. However, the methodology is based on hemodynamic surrogate measures, which are sensitive to patient activities such as posture changes, not necessarily related to blood pressure variations. In this paper, we analyze the impact of posture on the PAT measure and related hemodynamic parameters such as the pre-ejection period in well-defined procedures. Additionally, the PAT of a monitored subject is investigated in an unsupervised scenario illustrating the complexity of such a measurement. Our results show the failure of blood pressure inference based on simple calibration strategies using the PAT measure only. We discuss opportunities to compensate for the observed effects towards the realization of wearable cuff-less blood pressure monitoring. These findings emphasize the importance of accessing context information in personal healthcare applications, where vital sign monitoring is typically unsupervised.

  8. The impact of product’s packaging color on customers’ buying preferences under time pressure

    Directory of Open Access Journals (Sweden)

    Saad Ahmed Javed

    2015-05-01

    Full Text Available This research aims to test whether product’s packaging color influences customers’ purchasing preferences or not and does time pressure moderates this relationship? It studied the importance of color in determining customers’ buying preferences when they have limited time to do shopping. This study revealed that buying preference of a customer is relatively more dependent on the color scheme than on time constraint. However, time pressure was an important moderating factor which influenced the effect of packaging colors on customers’ purchasing preferences. This study emphasized that companies cannot afford to ignore the significance of time constraints and color scheme of the products on customers’ buying behavior.

  9. The cryogenic bonding evaluation at the metallic-composite interface of a composite overwrapped pressure vessel with additional impact investigation

    Science.gov (United States)

    Clark, Eric A.

    A bonding evaluation that investigated the cryogenic tensile strength of several different adhesives/resins was performed. The test materials consisted of 606 aluminum test pieces adhered to a wet-wound graphite laminate in order to simulate the bond created at the liner-composite interface of an aluminum-lined composite overwrapped pressure vessel. It was found that for cryogenic applications, a flexible, low modulus resin system must be used. Additionally, the samples prepared with a thin layer of cured resin -- or prebond -- performed significantly better than those without. It was found that it is critical that the prebond surface must have sufficient surface roughness prior to the bonding application. Also, the aluminum test pieces that were prepared using a surface etchant slightly outperformed those that were prepared with a grit blast surface finish and performed significantly better than those that had been scored using sand paper to achieve the desired surface finish. An additional impact investigation studied the post impact tensile strength of composite rings in a cryogenic environment. The composite rings were filament wound with several combinations of graphite and aramid fibers and were prepared with different resin systems. The rings were subjected to varying levels of Charpy impact damage and then pulled to failure in tension. It was found that the addition of elastic aramid fibers with the carbon fibers mitigates the overall impact damage and drastically improves the post-impact strength of the structure in a cryogenic environment.

  10. The Impact of Housing on the Characteristics of Ceramic Pressure Sensors—An Issue of Design for Manufacturability

    Science.gov (United States)

    Santo Zarnik, Marina; Belavic, Darko; Novak, Franc

    2015-01-01

    An exploratory study of the impact of housing on the characteristics of a low-temperature co-fired ceramic (LTCC) pressure sensor is presented. The ceramic sensor structure is sealed in a plastic housing. This may have non-negligible effect on the final characteristics and should be considered in the early design phase. The manufacturability issue mainly concerning the selection of available housing and the most appropriate materials was considered with respect to different requirements for low and high pressure ranges of operation. Numerical predictions showed the trends and helped reveal the critical design parameters. Proper selection of the adhesive material remains an essential issue. Curing of the epoxy adhesive may introduce non-negligible residual stresses, which considerably influence the sensor’s characteristics. PMID:26694386

  11. The Impact of Housing on the Characteristics of Ceramic Pressure Sensors—An Issue of Design for Manufacturability

    Directory of Open Access Journals (Sweden)

    Marina Santo Zarnik

    2015-12-01

    Full Text Available An exploratory study of the impact of housing on the characteristics of a low-temperature co-fired ceramic (LTCC pressure sensor is presented. The ceramic sensor structure is sealed in a plastic housing. This may have non-negligible effect on the final characteristics and should be considered in the early design phase. The manufacturability issue mainly concerning the selection of available housing and the most appropriate materials was considered with respect to different requirements for low and high pressure ranges of operation. Numerical predictions showed the trends and helped reveal the critical design parameters. Proper selection of the adhesive material remains an essential issue. Curing of the epoxy adhesive may introduce non-negligible residual stresses, which considerably influence the sensor’s characteristics.

  12. The Impact of Housing on the Characteristics of Ceramic Pressure Sensors--An Issue of Design for Manufacturability.

    Science.gov (United States)

    Santo Zarnik, Marina; Belavic, Darko; Novak, Franc

    2015-12-14

    An exploratory study of the impact of housing on the characteristics of a low-temperature co-fired ceramic (LTCC) pressure sensor is presented. The ceramic sensor structure is sealed in a plastic housing. This may have non-negligible effect on the final characteristics and should be considered in the early design phase. The manufacturability issue mainly concerning the selection of available housing and the most appropriate materials was considered with respect to different requirements for low and high pressure ranges of operation. Numerical predictions showed the trends and helped reveal the critical design parameters. Proper selection of the adhesive material remains an essential issue. Curing of the epoxy adhesive may introduce non-negligible residual stresses, which considerably influence the sensor's characteristics.

  13. Impact of Spatial Resolution on Wind Field Derived Estimates of Air Pressure Depression in the Hurricane Eye

    Directory of Open Access Journals (Sweden)

    Linwood Jones

    2010-03-01

    Full Text Available Measurements of the near surface horizontal wind field in a hurricane with spatial resolution of order 1–10 km are possible using airborne microwave radiometer imagers. An assessment is made of the information content of the measured winds as a function of the spatial resolution of the imager. An existing algorithm is used which estimates the maximum surface air pressure depression in the hurricane eye from the maximum wind speed. High resolution numerical model wind fields from Hurricane Frances 2004 are convolved with various HIRAD antenna spatial filters to observe the impact of the antenna design on the central pressure depression in the eye that can be deduced from it.

  14. Optical properties of the atmospheric pressure helium plasma jet generated by alternative current (a.c.) power supply

    Science.gov (United States)

    Ilik, Erkan; Akan, Tamer

    2016-05-01

    In this work, an atmospheric pressure plasma jet (APPJ) was produced to generate cold flowing post-discharge plasma of pure helium gas. The main aim of this study was to generate cold flowing APPJ of pure helium gas and to determine how their optical emission spectrum change influences varying different flow rates. Lengths of early, middle, and late post-discharge plasma (jet) regions and their fluctuations were determined, respectively. Then, ignition condition dependence of the post-discharge plasma for flow rate was specified at a constant voltage. Spectroscopic studies of an atmospheric pressure plasma jet of helium were presented via analyzing OH, N2, N2+, oxygen, and helium intensities for various flow rates.

  15. Predicting current and future peatmoss drought stress: Impact of hydrological complexity

    Science.gov (United States)

    Nijp, Jelmer; Metselaar, Klaas; Limpens, Juul; Teutschbein, Claudia; Peichl, Matthias; Nilsson, Mats; Berendse, Frank; van der Zee, Sjoerd

    2016-04-01

    Northern peatlands sequester enormous amounts of carbon and therefore represent a carbon store of global importance. The vegetation in northern peatlands is dominated by peat-forming bryophytes of the genus Sphagnum. The growth of this carbon fixer, and hence its carbon uptake, strongly depends on the moisture availability in the living moss layer, which is a function of both water table and rewetting by rain. Peatland hydrology models are used to predict how changes in climate may modify the future water balance of peatmoss carpets and influence associated carbon and energy balances. These models, however, differ considerably in the number and type of processes included, which will have yet unknown consequences for peatland drought predictions in a future climate. Here, we assessed the importance of rainwater storage and peat volume change for predicting peatmoss drought projections in northern peatlands using an ensemble of downscaled, bias-corrected climate scenarios for current (1991 - 2020) and future (2061 - 2090) climate. Peatmoss drought projections were compared among four model variants with or without rainwater storage in the peatmoss carpet and peat volume change, which are considered as two important hydrological feedbacks controlling moss moisture availability. The performance of the four model variants was assessed using field data from a site in northern Sweden (Degerö Stormyr, 64°N 19°E). Our results show that adding rainwater storage in the moss layer as well as peat volume change significantly improved model performance; the most complex model had best model performance. Compared to the reference model, including both model extensions reduced the predicted drought frequency experienced by peatmoss with around 50%. Moreover, projected climate change is expected to reduce predicted peatmoss drought stress with about 20% for the studied site. In conclusion, this study shows that including rainwater storage in the peatmoss layer and/or peat volume

  16. Magnetic field effects on the vestibular system: calculation of the pressure on the cupula due to ionic current-induced Lorentz force

    Science.gov (United States)

    Antunes, A.; Glover, P. M.; Li, Y.; Mian, O. S.; Day, B. L.

    2012-07-01

    Large static magnetic fields may be employed in magnetic resonance imaging (MRI). At high magnetic field strengths (usually from about 3 T and above) it is possible for humans to perceive a number of effects. One such effect is mild vertigo. Recently, Roberts et al (2011 Current Biology 21 1635-40) proposed a Lorentz-force mechanism resulting from the ionic currents occurring naturally in the endolymph of the vestibular system. In the present work a more detailed calculation of the forces and resulting pressures in the vestibular system is carried out using a numerical model. Firstly, realistic 3D finite element conductivity and fluid maps of the utricle and a single semi-circular canal containing the current sources (dark cells) and sinks (hair cells) of the utricle and ampulla were constructed. Secondly, the electrical current densities in the fluid are calculated. Thirdly, the developed Lorentz force is used directly in the Navier-Stokes equation and the trans-cupular pressure is computed. Since the driving force field is relatively large in comparison with the advective acceleration, we demonstrate that it is possible to perform an approximation in the Navier-Stokes equations that reduces the problem to solving a simpler Poisson equation. This simplification allows rapid and easy calculation for many different directions of applied magnetic field. At 7 T a maximum cupula pressure difference of 1.6 mPa was calculated for the combined ampullar (0.7 µA) and utricular (3.31 µA) distributed current sources, assuming a hair-cell resting current of 100 pA per unit. These pressure values are up to an order of magnitude lower than those proposed by Roberts et al using a simplistic model and calculation, and are in good agreement with the estimated pressure values for nystagmus velocities in caloric experiments. This modeling work supports the hypothesis that the Lorentz force mechanism is a significant contributor to the perception of magnetic field induced vertigo.

  17. Magnetic field effects on the vestibular system: calculation of the pressure on the cupula due to ionic current-induced Lorentz force.

    Science.gov (United States)

    Antunes, A; Glover, P M; Li, Y; Mian, O S; Day, B L

    2012-07-21

    Large static magnetic fields may be employed in magnetic resonance imaging (MRI). At high magnetic field strengths (usually from about 3 T and above) it is possible for humans to perceive a number of effects. One such effect is mild vertigo. Recently, Roberts et al (2011 Current Biology 21 1635-40) proposed a Lorentz-force mechanism resulting from the ionic currents occurring naturally in the endolymph of the vestibular system. In the present work a more detailed calculation of the forces and resulting pressures in the vestibular system is carried out using a numerical model. Firstly, realistic 3D finite element conductivity and fluid maps of the utricle and a single semi-circular canal containing the current sources (dark cells) and sinks (hair cells) of the utricle and ampulla were constructed. Secondly, the electrical current densities in the fluid are calculated. Thirdly, the developed Lorentz force is used directly in the Navier-Stokes equation and the trans-cupular pressure is computed. Since the driving force field is relatively large in comparison with the advective acceleration, we demonstrate that it is possible to perform an approximation in the Navier-Stokes equations that reduces the problem to solving a simpler Poisson equation. This simplification allows rapid and easy calculation for many different directions of applied magnetic field. At 7 T a maximum cupula pressure difference of 1.6 mPa was calculated for the combined ampullar (0.7 µA) and utricular (3.31 µA) distributed current sources, assuming a hair-cell resting current of 100 pA per unit. These pressure values are up to an order of magnitude lower than those proposed by Roberts et al using a simplistic model and calculation, and are in good agreement with the estimated pressure values for nystagmus velocities in caloric experiments. This modeling work supports the hypothesis that the Lorentz force mechanism is a significant contributor to the perception of magnetic field induced vertigo.

  18. Impact of financial pressure on unemployed job search, job find success and job quality

    NARCIS (Netherlands)

    Gerards, Ruud; Welters, Ricardo

    2016-01-01

    Research shows that financial pressure – implied as a consequence of benefit sanctions or exhaustion – prompts the unemployed to intensify their job search. However, there is less agreement about whether that intensified job search produces better quality job outcomes. Building on Self-Determination

  19. Impact of Age on the Importance of Systolic and Diastolic Blood Pressures for Stroke Risk

    DEFF Research Database (Denmark)

    Vishram, Julie K K; Borglykke, Anders; Andreasen, Anne H;

    2012-01-01

    This study investigates age-related shifts in the relative importance of systolic (SBP) and diastolic (DBP) blood pressures as predictors of stroke and whether these relations are influenced by other cardiovascular risk factors. Using 34 European cohorts from the MOnica, Risk, Genetics, Archiving...

  20. Impact on Clover-Grass Yield from Wheel Load and Tyre Pressure

    DEFF Research Database (Denmark)

    Green, Ole; Jørgensen, Rasmus Nyholm; Sørensen, Claus Aage Grøn

    2009-01-01

    Traffic intensities have been shown to have a negative influence on the yield of grass and clover. A full scale grass-clover field trial was established to estimate the effect on clover-grass yields as a function of different wheel loads and tire pressures. The trial comprised 16 different traffi...

  1. Impact of extracorporeal blood flow rate on blood pressure, pulse rate and cardiac output during haemodialysis

    DEFF Research Database (Denmark)

    Schytz, Philip Andreas; Mace, Maria Lerche; Soja, Anne Merete Boas

    2015-01-01

    BACKGROUND: If blood pressure (BP) falls during haemodialysis (HD) [intradialytic hypotension (IDH)] a common clinical practice is to reduce the extracorporeal blood flow rate (EBFR). Consequently the efficacy of the HD (Kt/V) is reduced. However, only very limited knowledge on the effect of redu...

  2. Visual Attention During Brand Choice : The Impact of Time Pressure and Task Motivation

    NARCIS (Netherlands)

    Pieters, R.; Warlop, L.

    1998-01-01

    Measures derived from eye-movement data reveal that during brand choice consumers adapt to time pressure by accelerating the visual scanning sequence, by filtering information and by changing their scanning strategy. In addition, consumers with high task motivation filter brand information less and

  3. Impact of ultrasound probe pressure on uterine positional displacement in gynecologic cancer patients

    DEFF Research Database (Denmark)

    Baker, Mariwan; Juhler-Nøttrup, Trine; Behrens, Claus F.

    2014-01-01

    Aim: The aim of this study was to quantify the uterine positional displacement induced by ultrasound probe pressure on a phantom and address the daily uterine motion in a healthy volunteer. Materials & methods: The phantom mimics the female pelvic region. The incorporated organs were subjected to...

  4. Impact of financial pressure on unemployed job search, job find success and job quality

    NARCIS (Netherlands)

    Gerards, Ruud; Welters, Ricardo

    2016-01-01

    Research shows that financial pressure – implied as a consequence of benefit sanctions or exhaustion – prompts the unemployed to intensify their job search. However, there is less agreement about whether that intensified job search produces better quality job outcomes. Building on Self-Determination

  5. Impact of gonadectomy on blood pressure regulation in ageing male and female rats

    NARCIS (Netherlands)

    Pijacka, Wioletta; Clifford, Bethan; Walas, Dawid; Tilburgs, Chantal; Joles, Jaap A.; McMullen, Sarah; Langley-Evans, Simon C.

    2016-01-01

    Background: Sexual dimorphism in blood pressure has been associated with differential expression of the angiotensin II (AII) receptors and with activity of the nervous system. It is generally accepted that ageing affects kidney function as well as autonomic nervous system and hormonal balance. Given

  6. Visual Attention During Brand Choice : The Impact of Time Pressure and Task Motivation

    NARCIS (Netherlands)

    Pieters, R.; Warlop, L.

    1998-01-01

    Measures derived from eye-movement data reveal that during brand choice consumers adapt to time pressure by accelerating the visual scanning sequence, by filtering information and by changing their scanning strategy. In addition, consumers with high task motivation filter brand information less and

  7. Impact on Clover-Grass Yield from Wheel Load and Tyre Pressure

    DEFF Research Database (Denmark)

    Green, Ole; Jørgensen, Rasmus Nyholm; Sørensen, Claus Aage Grøn

    2009-01-01

    Traffic intensities have been shown to have a negative influence on the yield of grass and clover. A full scale grass-clover field trial was established to estimate the effect on clover-grass yields as a function of different wheel loads and tire pressures. The trial comprised 16 different traffi...

  8. Relationship among diastolic intraventricular pressure gradients, relaxation, and preload : impact of age and fitness

    NARCIS (Netherlands)

    Popovic, Z.B.; Prasad, A.; Garcia, M.J.; Arbab-Zadeh, A.; Borowski, A.; Dijk, E.; Greenberg, N.L.; Levine, B.D.; Thomas, J.D.

    2006-01-01

    Diastolic intraventricular pressure gradients (IVPGs) are a measure of the ability of the ventricle to facilitate its filling using diastolic suction. We assessed 15 healthy young but sedentary subjects, aged <50 yr (young subjects; age, 35 +/- 9 yr); 13 healthy but sedentary seniors, aged >65 yr wi

  9. What is different for people with MS who have pressure ulcers: A reflective study of the impact upon people's quality of life?

    Science.gov (United States)

    McGinnis, Elizabeth; Andrea Nelson, E; Gorecki, Claudia; Nixon, Jane

    2015-08-01

    Multiple Sclerosis (MS) is a progressive, degenerative disease of the central nervous system. People with advanced disease who have compromised mobility, activity, sensory and/or cognitive abilities are at risk of pressure ulcers. Having a pressure ulcer has a substantial impact on a person's quality of life; a generic pressure ulcer Health Related Quality of Life (HRQL) framework has been used in this study. To explore the views and opinions of patients with MS who have a pressure ulcer using a thematic framework and compare these to the general pressure ulcer population. Data for six MS patients was obtained through secondary analysis of transcripts from semi-structured interviews conducted during two studies which were part of a programme of HRQL Research. Patients with MS reported that their pressure ulcer affected their lives physically, psychologically and socially. All were confined to bed (as part of their pressure ulcer treatment) and therefore unable to participate in activities. Difficulties with movement and activity were partially attributed to the MS. Patients with MS did not report feeling ill with their pressure ulcer and expressed positive emotions and optimism. Pain or discomfort was a feature of the pressure ulcer for most patients. Pressure ulcers have a major impact on QOL for all patients. Problems with mobility and activity associated with the pressure ulcer were confounded by the MS. Copyright © 2015 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  10. The impact of arm position and pulse pressure on the validation of a wrist-cuff blood pressure measurement device in a high risk population

    Directory of Open Access Journals (Sweden)

    Ali Reza Khoshdel

    2010-03-01

    Full Text Available Ali Reza Khoshdel1,2, Shane Carney2, Alastair Gillies21Faculty of Medicine, Aja University of Medical Science, Tehran, Iran; 2John Hunter Hospital, Faculty of Health, The University of Newcastle, Newcastle, NS W, AustraliaAbstract: Despite the increasing popularity of blood pressure (BP wrist monitors for self-BP measurement at home, device validation and the effect of arm position remains an issue. This study focused on the validation of the Omron HEM-609 wrist BP device, including an evaluation of the impact of arm position and pulse pressure on BP measurement validation. Fifty patients at high risk for cardiovascular disease were selected (age 65 ± 10 years. Each patient had two measurements with a mercury sphygmomanometer and three measurements with the wrist BP device (wrist at the heart level while the horizontal arm supported [HORIZONTAL], hand supported on the opposite shoulder [SHOULDER], and elbow placed on a desk [DESK], in random order. The achieved systolic BP (SBP and diastolic BP (DBP wrist-cuff readings were compared to the mercury device and the frequencies of the readings within 5, 10, and 15 mmHg of the gold standard were computed and compared with the British Hypertension Society (BHS and Association for the Advancement of Medical Instrumentation (AAMI protocols. The results showed while SBP readings with HORIZONTAL and SHOULDER positions were significantly different from the mercury device (mean difference = 7.1 and 13.3 mmHg, respectively; P < 0.05, the DESK position created the closest reading to mercury (mean difference = 3.8, P > 0.1. Approximately 71% of SBP readings with the DESK position were within ±10 mmHg, whereas it was 62.5% and 34% for HORIZONTAL and SHOULDER positions, respectively. Wrist DBP attained category D with BHS criteria with all three arm positions. Bland–Altman plots illustrated that the wrist monitor systematically underestimated SBP and DBP values. However a reading adjustment of 5 and 10 mm

  11. The Impact of Climate Changes on the Thermal Performance of a Proposed Pressurized Water Reactor: Nuclear-Power Plant

    Directory of Open Access Journals (Sweden)

    Said M. A. Ibrahim

    2014-01-01

    Full Text Available This paper presents a methodology for studying the impact of the cooling water temperature on the thermal performance of a proposed pressurized water reactor nuclear power plant (PWR NPP through the thermodynamic analysis based on the thermodynamic laws to gain some new aspects into the plant performance. The main findings of this study are that an increase of one degree Celsius in temperature of the coolant extracted from environment is forecasted to decrease by 0.39293 and 0.16% in the power output and the thermal efficiency of the nuclear-power plant considered, respectively.

  12. Impact of climate change on large scale coastal currents of South Africa

    CSIR Research Space (South Africa)

    Meyer, A

    2010-09-01

    Full Text Available The increase in equatorial temperatures and the presence of an ozone hole over Antarctica have caused an increase in the pole-to-equator pressure gradient with a concomitant intensification of the high-latitude westerlies (Cai et al., 2006...

  13. Intelligent MTconnect. Eddy-Current Valve Probe Pilot Project within the High Pressure Gas Facility (HPGF) Liquid Nitrogen Evaporator Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will perform real-time collection of prognostic valve operational data by deploying smart eddy-current probes with the use of the MTconnect® system,...

  14. The Impact of Diabetes on Gynecologic Cancer: Current Status and Future Directions

    OpenAIRE

    Lees, Brittany; Leath, Charles A.

    2015-01-01

    Diabetes mellitus has reached epidemic proportions in both the United States and worldwide with most authorities reporting a doubling in the prevalence of diabetes over the last 20–30 years. While this epidemic is closely tied to obesity, diabetes mellitus presents potential clinical challenges over and above that observed with obesity alone. From a women’s health care prospective, this rise in diabetes may impact a woman’s health across her lifespan. More specifically, diabetes impacts not o...

  15. Plate impact experiments on the TATB based explosive PBX 9502 at pressures near the Chapman-Jouguet state

    Science.gov (United States)

    Gustavsen, R. L.; Aslam, T. D.; Bartram, B. D.; Hollowell, B. C.

    2014-05-01

    A series of two-stage gus-gun driven plate impact experiments on PBX 9502 (95 wt.% tri-amino-trinitro-benzene, 5 wt.% Kel-F800 plastic binder) was completed in the 28-34 GPa pressure range. This is just above the Chapman-Jouguet state of ≈ 28 GPa. The experiments consisted of a thick oxygen free high conductivity copper (OFHC Cu) flyer plate impacting a PBX 9502 sample backed by a Lithium Fluoride (LiF) window. Photonic Doppler Velocimetry (PDV) was used to measure velocity histories (wave profiles) at the PBX 9502/LiF interface. Shock transit times and sample thicknesses were converted to shock velocities, Us. Particle velocities, up, were calculated by way of impedance matching. Lastly, the measured wave profiles were compared with numerical simulations of the experiments using the Wescott-Stewart-Davis reactive-burn model.

  16. The impact of open access on the medical literature: a review of current literature

    Directory of Open Access Journals (Sweden)

    Nana Turk

    2017-02-01

    Full Text Available Background: the aim of the article is to conduct an overview of the impact of OA on the medical articles based on 3-part categorization.Methods: Data were identified by a search strategy with eight combinations of keywords (open access, citation impact, citation advantage, citation count, article download, article usage, social media attention, altmetrics and searched in three different databases.Results: the analysis was conducted on 107 studies dealing with citations, downloads and social impact. Sixty-seven of them simply employed the counting citations to OA and non-OA articles; nineteen articles compared the downloads and citations counts; and twenty-one articles investigated the social impact of OA articles. Twenty-five articles investigated the citations, download counts, and social impact of medical articles.Conclusions: The studies investigating the citation impact mostly showed citation advantages. Those that employed citation and download counts of medical articles using randomized controlled trials showed that OA articles were downloaded significantly more frequently, but found no evidence of a citation advantage for open access articles. The citation advantage from open access might be caused by other factors. Results of the studies comparing the social media attention and citations/downloads of the medical articles are often diametrically opposed.

  17. The impacts of trail infrastructure on vegetation and soils: Current literature and future directions.

    Science.gov (United States)

    Ballantyne, Mark; Pickering, Catherine Marina

    2015-12-01

    Reflecting the popularity of nature-based activities such as hiking and mountain biking, there are thousands of kilometres of recreational trails worldwide traversing a range of natural areas. These trails have environmental impacts on soils and vegetation, but where has there been research, what impacts have been found and how were they measured? Using a systematic quantitative literature review methodology, we assessed the impacts of trails on vegetation and soils, highlighting what is known, but also key knowledge gaps. Of the 59 original research papers identified on this topic that have been published in English language peer-reviewed academic journals, most were for research conducted in protected areas (71%), with few from developing countries (17%) or threatened ecosystems (14%). The research is concentrated in a few habitats and biodiversity hotspots, mainly temperate woodland, alpine grassland and Mediterranean habitats, often in the USA (32%) or Australia (20%). Most examined formal trails, with just 15% examining informal trails and 11% assessing both types. Nearly all papers report the results of observational surveys (90%), collecting quantitative data (66%) with 24% using geographic information systems. There was an emphasis on assessing trail impacts at a local scale, either on the trail itself and/or over short gradients away from the trail edge. Many assessed changes in composition and to some degree, structure, of vegetation and soils with the most common impacts documented including reduced vegetation cover, changes in plant species composition, trail widening, soil loss and soil compaction. There were 14 papers assessing how these local impacts can accumulate at the landscape scale. Few papers assessed differences in impacts among trails (7 papers), changes in impacts over time (4), species-specific responses (3) and only one assessed effects on plant community functioning. This review provides evidence that there are key research gaps

  18. Ultra-high pressure homogenization-induced changes in skim milk: impact on acid coagulation properties.

    Science.gov (United States)

    Serra, Mar; Trujillo, Antonio J; Jaramillo, Pamela D; Guamis, Buenaventura; Ferragut, Victoria

    2008-02-01

    The effects of ultra-high pressure homogenization (UHPH) on skim milk yogurt making properties were investigated. UHPH-treated milk was compared with conventionally homogenised (15 MPa) heat-treated skim milk (90 degrees C for 90 s), and to skim milk treated under the same thermal conditions but fortified with 3% skim milk powder. Results of the present study showed that UHPH is capable of reducing skim milk particle size which leads to the formation of finer dispersions than those obtained by conventional homogenisation combined with heat treatment. In addition, results involving coagulation properties and yogurt characteristics reflected that, when increasing UHPH pressure conditions some parameters such as density of the gel, aggregation rate and water retention are improved.

  19. Hazard of pyroclastic density currents at the Campi Flegrei Caldera (Southern Italy) as deduced from the combined use of facies architecture, physical modeling and statistics of the impact parameters

    Science.gov (United States)

    Mele, D.; Dioguardi, F.; Dellino, P.; Isaia, R.; Sulpizio, R.; Braia, G.

    2015-06-01

    Pyroclastic density currents of the recent eruptions at Campi Flegrei Caldera (CFC - Southern Italy) have been studied with the aim of assessing the potential impact of similar events in the future. Eruptions of different scales have been investigated by means of the combined use of facies architecture, laboratory analysis and physical modeling. Both in the small (Averno 2) and intermediate (Astroni) scales, facies analysis indicates that deposits result from the emplacement of pyroclastic density currents like base-surge, formed by multiple closely-timed impulses of phreatomagmatic origin. In the large-scale event (Agnano-Monte Spina), the facies architecture suggests that the currents started as concentrated flows near the vent, as originating from the collapse of a dense eruptive column, and evolved laterally into expanded flows by the propagation of the basal shear current. Laboratory analyses on samples from the main layers of deposits allowed obtaining the input data for the PYFLOW code, which was used for reconstructing the flow dynamic characteristics of the currents. The expected damage is discussed in terms of the probability density function of dynamic pressure and particle volumetric concentration. In this way, the range of potential impact that similar pyroclastic density currents could cause to buildings, infrastructures and population is defined. In the large-scale event, the dynamic pressure ranges from 9.38 to 1.00 kPa (integrating the basal 10 m of the current) at distances of 1.5 and 4.0 km from the vent, respectively. The values are highly influenced by the local topography. In the intermediate-scale event, the dynamic pressure ranges from 2.43 to 0.26 kPa at distances of 1.1 and 1.4 km from the vent, respectively. In the small scale event, the dynamic pressure ranges from 1.49 to 0.39 kPa at distances of 0.5 and 1.1 km from the vent, respectively. The particle volumetric concentration at a height of 2 m within the current is always lower than 0

  20. 我国稻米产业现状及发展对策%Current Situation,Pressure and Development Countermeasures on Chinese Rice Industry

    Institute of Scientific and Technical Information of China (English)

    孙强; 刘心雨; 张三元; 张俊国

    2011-01-01

    It pointed out facing pressure about chinese rice industry from current situation such as the pressure about cost and price,the pressure of foodstuff circulation system,the pressure of exotic products,the pressure of green barriers and the new pressure of national food protection policy.It proposed development countermeasures of rice industry such as support to leading enterprises,advance industrialization of rice,build risk system on production,strengthen safety standard and checkout on rice and analysis on the pest quarantine of foreign seed,pay attention to the diversity to develop rice,reform circulation system of food and so on,all these can provide scientific evidence for the development for rice industry.%针对中国稻米产业的现状,指出中国稻米产业面临的压力:价格与成本的压力;粮食流通体制上的压力;外国以精新产品打入中国市场的压力;绿色壁垒的压力;国家粮食保护政策面临新压力。提出了中国稻米产业今后发展的对策:扶持龙头企业,推进稻米产业化发展;建立生产风险制度;加强稻米安全标准和检验及国外种子病虫害检疫研究;注重开发稻米的多样性;改革粮食流通体制等,为稻米产业发展提供科学参考。

  1. Impact of obstructive sleep apnea on blood pressure in patients with hypertension

    Directory of Open Access Journals (Sweden)

    Gurubhagavatula I

    2011-12-01

    Full Text Available Barry Fields1, Indira Gurubhagavatula1–31Division of Sleep Medicine, Perelman School of Medicine, University of Pennsylvania, 2Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, 3Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USAAbstract: Hypertension is the most significant risk factor for death worldwide. Approximately 30%–40% of affected individuals have coexisting obstructive sleep apnea (OSA, a disorder resulting from the upper airway’s inability to remain patent during sleep. A causal relationship between OSA and hypertension has been demonstrated. Blunting or elimination of normal blood pressure (BP dipping during sleep is commonly seen in OSA patients, with corresponding increases in daytime BP. This dipping is clinically salient, because it is associated with the end-organ damage seen with chronic hypertension, such as cardiovascular, renal, and cerebrovascular disease. African-Americans are at greatest risk for non-dipping and end-organ damage. Rapidly fluctuating changes in sympathetic tone, intrathoracic pressure, oxyhemoglobin saturation, and carbon dioxide levels are all thought to play a role in acute and chronic BP elevation. Individuals with preexisting hypertension are most susceptible to OSA’s BP-raising effects. First-line therapy for OSA includes continuous positive airway pressure (CPAP delivered via a mask interface. Patients who show the greatest BP declines while using CPAP are more likely to be those who have at least moderate OSA, adhere to therapy, have preexisting hypertension, and whose blood vessels retain reversibility in disease-related remodeling. Given the heavy burden OSA-related hypertension places on the healthcare system, prevention, early detection, and prompt intervention should be the goals for all affected individuals.Keywords: obstructive sleep apnea (OSA, hypertension, nocturnal dipping, continuous positive airway pressure (CPAP

  2. On the impact of the magnitude of Interstellar pressure on physical properties of Molecular Cloud

    Science.gov (United States)

    Anathpindika, S.; Burkert, A.; Kuiper, R.

    2017-01-01

    Recently reported variations in the typical physical properties of Galactic and extra-Galactic molecular clouds (MCs), and in their star-forming ability have been attributed to local variations in the magnitude of interstellar pressure. Inferences from these surveys have called into question two long-standing beliefs : (1) that MCs are Virialised, and (2) they obey the Larson's third law. Here we invoked the framework of cloud-formation via collision between warm gas-flows to examine if these latest observational inferences can be reconciled. To this end we traced the temporal evolution of the gas surface density, the fraction of dense gas, the distribution of gas column density (N-PDF), and the Virial nature of the assembled clouds. We conclude, these physical properties exhibit temporal variation and their respective peak-magnitude also increases in proportion with the magnitude of external pressure, Pext. The velocity dispersion in assembled clouds appears to follow the power-law, σ _{gas}∝ P_{ext}^{0.23}. The power-law tail at higher densities becomes shallower with increasing magnitude of external pressure for Pext/kB ≲ 107 K cm-3; at higher magnitudes such as those typically found in the Galactic CMZ (Pext/kB > 107 K cm-3), the power-law shows significant steepening. While our results are broadly consistent with inferences from various recent observational surveys, it appears, MCs do not exhibit a unique set of properties, but rather a wide variety that can be reconciled with a range of magnitudes of pressure between 104 K cm-3 - 108 K cm-3.

  3. The impact of social pressure and monetary incentive on cognitive control

    Directory of Open Access Journals (Sweden)

    MINA eLIČEN

    2016-02-01

    Full Text Available In this study, we compare the effects of two prominent organizational control mechanisms—monetary incentive and social pressure—on cognitive control. Cognitive control underlies the human ability to regulate thoughts and actions in the pursuit of behavioral goals. Previous studies show that monetary incentives can contribute to goal-oriented behavior via the activation of proactive control. There is, however, much less evidence on the effect of social pressure on cognitive control and task performance. In a within-subject experimental design, we tested 47 subjects performing the AX-CPT task to compare the activation of cognitive control modes under monetary incentive and social pressure beyond mere instructions to perform better. We find that social pressure and monetary incentive have similar effects as mere instructions on cognitive control. All three lead to a significant shift from a reactive to a proactive control mode and a similar improvement in task performance. Our findings suggest that social control mechanisms and monetary incentives provide similar behavioral effects in stimulating a proactive cognitive control mode and performance.

  4. Impact of transcranial direct current stimulation (tDCS) on neuronal functions

    NARCIS (Netherlands)

    Das, S. (Suman); P. Holland (Peter); M.A. Frens (Maarten); O. Donchin (Opher)

    2016-01-01

    textabstractTranscranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, modulates neuronal excitability by the application of a small electrical current. The low cost and ease of the technique has driven interest in potential clinical applications. However, outcomes a

  5. The impact of the ocean observing system on estimates of the California current circulation spanning three decades

    Science.gov (United States)

    Moore, Andrew M.; Jacox, Michael G.; Crawford, William J.; Laughlin, Bruce; Edwards, Christopher A.; Fiechter, Jérôme

    2017-08-01

    Data assimilation is now used routinely in oceanography on both regional and global scales for computing ocean circulation estimates and for making ocean forecasts. Regional ocean observing systems are also expanding rapidly, and observations from a wide array of different platforms and sensor types are now available. Evaluation of the impact of the observing system on ocean circulation estimates (and forecasts) is therefore of considerable interest to the oceanographic community. In this paper, we quantify the impact of different observing platforms on estimates of the California Current System (CCS) spanning a three decade period (1980-2010). Specifically, we focus attention on several dynamically related aspects of the circulation (coastal upwelling, the transport of the California Current and the California Undercurrent, thermocline depth and eddy kinetic energy) which in many ways describe defining characteristics of the CCS. The circulation estimates were computed using a 4-dimensional variational (4D-Var) data assimilation system, and our analyses also focus on the impact of the different elements of the control vector (i.e. the initial conditions, surface forcing, and open boundary conditions) on the circulation. While the influence of each component of the control vector varies between different metrics of the circulation, the impact of each observing system across metrics is very robust. In addition, the mean amplitude of the circulation increments (i.e. the difference between the analysis and background) remains relatively stable throughout the three decade period despite the addition of new observing platforms whose impact is redistributed according to the relative uncertainty of observations from each platform. We also consider the impact of each observing platform on CCS circulation variability associated with low-frequency climate variability. The low-frequency nature of the dominant climate modes in this region allows us to track through time the

  6. The economics of pressure relieving surfaces: an illustrative case study of the impact of high-specification surfaces on hospital finances.

    Science.gov (United States)

    Trueman, Paul; Whitehead, Sarah J

    2010-02-01

    Pressure ulcers are associated with a significant economic burden that, in many cases, is recognised as being avoidable. The effectiveness of pressure relieving surfaces is well documented and acknowledged in clinical guidelines on the prevention and management of pressure ulcers. Whilst pressure relieving surfaces are more expensive than traditional hospital mattresses, judicious use, targeted to patients most at risk, can help to reduce the incidence and costs of pressure ulcers in hospital settings. This review paper includes a summary of pivotal clinical evidence on pressure relieving surfaces as well as a suggested approach for modelling their financial impact on hospital budgets. Simple financial modelling suggests that pressure relieving surfaces could lead to financial savings for a hospital when used appropriately.

  7. Cradle-to-Gate Impact Assessment of a High-Pressure Die-Casting Safety-Relevant Automotive Component

    Science.gov (United States)

    Cecchel, Silvia; Cornacchia, Giovanna; Panvini, Andrea

    2016-09-01

    The mass of automotive components has a direct influence on several aspects of vehicle performance, including both fuel consumption and tailpipe emissions, but the real environmental benefit has to be evaluated considering the entire life of the products with a proper life cycle assessment. In this context, the present paper analyzes the environmental burden connected to the production of a safety-relevant aluminum high-pressure die-casting component for commercial vehicles (a suspension cross-beam) considering all the phases connected to its manufacture. The focus on aluminum high-pressure die casting reflects the current trend of the industry and its high energy consumption. This work shows a new method that deeply analyzes every single step of the component's production through the implementation of a wide database of primary data collected thanks to collaborations of some automotive supplier companies. This energy analysis shows significant environmental benefits of aluminum recycling.

  8. Impact of current cough on health-related quality of life in patients with COPD

    Directory of Open Access Journals (Sweden)

    Deslee G

    2016-09-01

    [FEV1]: 57 [37–72] % predicted (median [Q1–Q3]. In univariate analyses, health-related quality of life (Saint George’s respiratory questionnaire total score was associated with each CASA-Q domain and with chronic bronchitis, exacerbations, dyspnea, FEV1, depression, and anxiety. All four domains introduced separately were independently associated with health-related quality of life. When introduced together in multivariate analyses, only the cough impact domain remained independently associated with health-related quality of life (R2=0.60. With chronic bronchitis (standard definition instead of the CASA-Q, the R2 was lower (R2=0.54.Conclusion: This study provides evidence that current cough in the previous 7 days is an important determinant of health-related quality of life impairment in stable COPD patients.Keywords: signs and symptoms, respiratory, sputum, questionnaires, dyspnea, multivariate analysis

  9. Portosystemic pressure reduction achieved with TIPPS and impact of portosystemic collaterals for the prediction of the portosystemic-pressure gradient in cirrhotic patients

    Energy Technology Data Exchange (ETDEWEB)

    Grözinger, Gerd, E-mail: gerd.groezinger@med.uni-tuebingen.de [Department of Diagnostic Radiology, Department of Radiology, University of Tübingen (Germany); Wiesinger, Benjamin; Schmehl, Jörg; Kramer, Ulrich [Department of Diagnostic Radiology, Department of Radiology, University of Tübingen (Germany); Mehra, Tarun [Department of Dermatology, University of Tübingen (Germany); Grosse, Ulrich; König, Claudius [Department of Diagnostic Radiology, Department of Radiology, University of Tübingen (Germany)

    2013-12-01

    Purpose: The portosystemic pressure gradient is an important factor defining prognosis in hepatic disease. However, noninvasive prediction of the gradient and the possible reduction by establishment of a TIPSS is challenging. A cohort of patients receiving TIPSS was evaluated with regard to imaging features of collaterals in cross-sectional imaging and the achievable reduction of the pressure gradient by establishment of a TIPSS. Methods: In this study 70 consecutive patients with cirrhotic liver disease were retrospectively evaluated. Patients received either CT or MR imaging before invasive pressure measurement during TIPSS procedure. Images were evaluated with regard to esophageal and fundus varices, splenorenal collaterals, short gastric vein and paraumbilical vein. Results were correlated with Child stage, portosystemic pressure gradient and post-TIPSS reduction of the pressure gradient. Results: In 55 of the 70 patients TIPSS reduced the pressure gradient to less than 12 mmHg. The pre-interventional pressure and the pressure reduction were not significantly different between Child stages. Imaging features of varices and portosystemic collaterals did not show significant differences. The only parameter with a significant predictive value for the reduction of the pressure gradient was the pre-TIPSS pressure gradient (r = 0.8, p < 0.001). Conclusions: TIPSS allows a reliable reduction of the pressure gradient even at high pre-interventional pressure levels and a high collateral presence. In patients receiving TIPSS the presence and the characteristics of the collateral vessels seem to be too variable to draw reliable conclusions concerning the portosystemic pressure gradient.

  10. Impact of Dietary Acculturation on the Food Habits, Weight, Blood Pressure, and Fasting Blood Glucose Levels of International College Students.

    Science.gov (United States)

    Almohanna, Amal; Conforti, Frank; Eigel, William; Barbeau, William

    2015-01-01

    This study was conducted to determine the impact of dietary acculturation on the health status of newly arrived international students at Virginia Tech in Fall 2010. Thirty-five international students, 18-36 years of age, completed the study. Data were collected at 3 different time periods (V1, V2, and V3) approximately 6 weeks apart. A food frequency- and dietary pattern-related questionnaire was administered and numerically coded responses were analyzed. Twenty-four-hour dietary recall data were also collected at V1, V2, and V3. Body weight, fasting blood glucose level, and blood pressure of study participants were also determined at each time period. Total sample population (TSP) had a significant increase in mean weight of 2.79 lb from visit 1 (V1) to visit 3 (V3) (p = .0082). Ten participants gained an average of 9.0 lb (participants who gained weight; n = 10). There was also an increase in the frequency of consumption of high-calorie American food items from V1 to V3. However, there were no significant changes in mean systolic blood pressure and mean fasting blood glucose was significantly lower at V3 than at V1. There was a gradual shift in the dietary patterns of international students towards the American diet. Dietary acculturation led to weight gain among some of the students, which may potentially have a negative impact on their health status if continued for longer time periods.

  11. Deep Submarine Tailings Disposal (DSTP) the Proposed Use of Submarine Canyons and Artificial Turbidity Currents for the Disposal of Mine Waste: Current Practice, Future Plans, and Cumulative Impacts.

    Science.gov (United States)

    Young, R.; Moran, R.

    2015-12-01

    The wastes from mining operations ( tailings) have been disposed of in the fluvial environment (riverine disposal) and in nearshore marine environments for much of the last century. The scale of modern mining operations has led to increasing use of steep slopes and submarine canyons for deposition of these wastes at depths of 2000m - 4000m. Current mine disposal operations in Indonesia and Papua New Guinea which use Deep Sea Tailings Placement (DSTP) release volumes between 5000 tpd and 160,000 tpd. Planning is underway by the"Consortium," an industry and government group in Chile which would deposit mine waste of 1M tpd into the Humbolt Current Large Marine Ecosystem (HCLME) which provides nearly 20% of the fish biomass harvested on a sustainable basis worldwide. Underwater pipelines discharge tailings as a slurry to create a continuous artificial turbidity current with particle size distribtions (PSD's) ranging from sand to clay sized fractions. Potential problems arise from benthic smothering, angular particulate uptake by benthic organisms, and from the bioaccumulation of a complex of heavy metals by both benthic and pelagic species. While much is known about the binding of copper and other toxic heavy metals in a reducing environment, little has been done to consider the implications of ocean dumping where 1% of tailings discharged may consist of unrecovered heavy metals. Synergistic cumulative impacts to just the HCLME from the dumping of the more than 3M tpy of reactive metals in these tailings sediments remains unknown and poses substantial risks. DSTP assumes a stable deep sea depositional environment but upwelling currents and plume shear may make this hard to accomplish.

  12. Microbial oil-degradation under mild hydrostatic pressure (10 MPa): which pathways are impacted in piezosensitive hydrocarbonoclastic bacteria?

    Science.gov (United States)

    Scoma, Alberto; Barbato, Marta; Hernandez-Sanabria, Emma; Mapelli, Francesca; Daffonchio, Daniele; Borin, Sara; Boon, Nico

    2016-03-01

    Oil spills represent an overwhelming carbon input to the marine environment that immediately impacts the sea surface ecosystem. Microbial communities degrading the oil fraction that eventually sinks to the seafloor must also deal with hydrostatic pressure, which linearly increases with depth. Piezosensitive hydrocarbonoclastic bacteria are ideal candidates to elucidate impaired pathways following oil spills at low depth. In the present paper, we tested two strains of the ubiquitous Alcanivorax genus, namely A. jadensis KS_339 and A. dieselolei KS_293, which is known to rapidly grow after oil spills. Strains were subjected to atmospheric and mild pressure (0.1, 5 and 10 MPa, corresponding to a depth of 0, 500 and 1000 m, respectively) providing n-dodecane as sole carbon source. Pressures equal to 5 and 10 MPa significantly lowered growth yields of both strains. However, in strain KS_293 grown at 10 MPa CO2 production per cell was not affected, cell integrity was preserved and PO43- uptake increased. Analysis of its transcriptome revealed that 95% of its genes were downregulated. Increased transcription involved protein synthesis, energy generation and respiration pathways. Interplay between these factors may play a key role in shaping the structure of microbial communities developed after oil spills at low depth and limit their bioremediation potential.

  13. Microbial oil-degradation under mild hydrostatic pressure (10 MPa): which pathways are impacted in piezosensitive hydrocarbonoclastic bacteria?

    KAUST Repository

    Scoma, Alberto

    2016-03-29

    Oil spills represent an overwhelming carbon input to the marine environment that immediately impacts the sea surface ecosystem. Microbial communities degrading the oil fraction that eventually sinks to the seafloor must also deal with hydrostatic pressure, which linearly increases with depth. Piezosensitive hydrocarbonoclastic bacteria are ideal candidates to elucidate impaired pathways following oil spills at low depth. In the present paper, we tested two strains of the ubiquitous Alcanivorax genus, namely A. jadensis KS_339 and A. dieselolei KS_293, which is known to rapidly grow after oil spills. Strains were subjected to atmospheric and mild pressure (0.1, 5 and 10 MPa, corresponding to a depth of 0, 500 and 1000 m, respectively) providing n-dodecane as sole carbon source. Pressures equal to 5 and 10 MPa significantly lowered growth yields of both strains. However, in strain KS_293 grown at 10 MPa CO2 production per cell was not affected, cell integrity was preserved and PO43− uptake increased. Analysis of its transcriptome revealed that 95% of its genes were downregulated. Increased transcription involved protein synthesis, energy generation and respiration pathways. Interplay between these factors may play a key role in shaping the structure of microbial communities developed after oil spills at low depth and limit their bioremediation potential.

  14. Regulatory Impact Assessment: Its Current Status and Development Prospects in Russia

    Directory of Open Access Journals (Sweden)

    A V Minaev

    2011-12-01

    Full Text Available The article examines the procedure of Regulatory Impact Assessment (RIA, which is widely used in developed countries for elaborating and making state-level decisions and is new to Russia. The paper analyzes the origins and essential features of the RIA model applied abroad, reviews major methodological approaches to the preparation of statements on regulatory impact assessment. The study focuses on the Russian RIA model, describing its differences from the foreign analogues; the paper also analyzes the shortcomings of this model. A forecast for the development of RIA in Russia is made by the author.

  15. Impact of Intellectual Property in National and Business Development under the Context of the Current Globalization

    Directory of Open Access Journals (Sweden)

    Stalin Ballesteros García

    2016-12-01

    Full Text Available The objective of the document is to show the impact of the intellectual property on the national and enterprise development in the globalization context since the early twenty-first century. First, it is a historical telling of the intellectual property and its role in the international society; then outlining the arguments to infer the incidence degree of the intellectual property in the economic development of countries and then discussing the inclusion impact of concepts directly related to the intellectual property in business growth activities. It concludes with a reflection on the Colombian situation, in public and private context, in terms of intellectual property.

  16. Strategies to reduce the environmental impact of an aluminium pressure die casting plant: A scenario analysis

    NARCIS (Netherlands)

    Neto, B.; Kroeze, C.; Hordijk, L.; Costa, C.; Pulles, M.P.J.

    2009-01-01

    This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze,

  17. Strategies to reduce the environmental impact of an aluminium pressure die casting plant: A scenario analysis

    NARCIS (Netherlands)

    Neto, B.; Kroeze, C.; Hordijk, L.; Costa, C.; Pulles, M.P.J.

    2009-01-01

    This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze,

  18. The Impact of Historical and Current Loss on Chronic Illness: Perceptions of Crow (Apsáalooke) People

    Science.gov (United States)

    Bird, Sloane Real; Held, Suzanne; McCormick, Alma; Hallett, John; Martin, Christine; Trottier, Coleen

    2017-01-01

    The purpose of this research was to gain a better understanding of perceptions about the impact of historical and current loss on Apsáalooke (Crow) people acquiring and coping with chronic illness. This study took a qualitative phenomenological approach by interviewing community members with chronic illness in order to gain insight into their perceptions and experiences. Participants emphasized 10 areas of impact of historical and current loss: the link between mental health and physical health/health behaviors; resiliency and strengths; connection and isolation; importance of language and language loss; changes in cultural knowledge and practices; diet; grieving; racism and discrimination; changes in land use and ownership; and boarding schools. The findings from this research are being used to develop a chronic illness self-care management program for Crow people.

  19. Impact of organic nutrient load on biomass accumulation, feed channel pressure drop increase and permeate flux decline in membrane systems

    KAUST Repository

    Bucs, Szilard

    2014-12-01

    The influence of organic nutrient load on biomass accumulation (biofouling) and pressure drop development in membrane filtration systems was investigated. Nutrient load is the product of nutrient concentration and linear flow velocity. Biofouling - excessive growth of microbial biomass in membrane systems - hampers membrane performance. The influence of biodegradable organic nutrient load on biofouling was investigated at varying (i) crossflow velocity, (ii) nutrient concentration, (iii) shear, and (iv) feed spacer thickness. Experimental studies were performed with membrane fouling simulators (MFSs) containing a reverse osmosis (RO) membrane and a 31 mil thick feed spacer, commonly applied in practice in RO and nanofiltration (NF) spiral-wound membrane modules. Numerical modeling studies were done with identical feed spacer geometry differing in thickness (28, 31 and 34 mil). Additionally, experiments were done applying a forward osmosis (FO) membrane with varying spacer thickness (28, 31 and 34 mil), addressing the permeate flux decline and biofilm development. Assessed were the development of feed channel pressure drop (MFS studies), permeate flux (FO studies) and accumulated biomass amount measured by adenosine triphosphate (ATP) and total organic carbon (TOC).Our studies showed that the organic nutrient load determined the accumulated amount of biomass. The same amount of accumulated biomass was found at constant nutrient load irrespective of linear flow velocity, shear, and/or feed spacer thickness. The impact of the same amount of accumulated biomass on feed channel pressure drop and permeate flux was influenced by membrane process design and operational conditions. Reducing the nutrient load by pretreatment slowed-down the biofilm formation. The impact of accumulated biomass on membrane performance was reduced by applying a lower crossflow velocity and/or a thicker and/or a modified geometry feed spacer. The results indicate that cleanings can be delayed

  20. Impact of organic nutrient load on biomass accumulation, feed channel pressure drop increase and permeate flux decline in membrane systems.

    Science.gov (United States)

    Bucs, Sz S; Valladares Linares, R; van Loosdrecht, M C M; Kruithof, J C; Vrouwenvelder, J S

    2014-12-15

    The influence of organic nutrient load on biomass accumulation (biofouling) and pressure drop development in membrane filtration systems was investigated. Nutrient load is the product of nutrient concentration and linear flow velocity. Biofouling - excessive growth of microbial biomass in membrane systems - hampers membrane performance. The influence of biodegradable organic nutrient load on biofouling was investigated at varying (i) crossflow velocity, (ii) nutrient concentration, (iii) shear, and (iv) feed spacer thickness. Experimental studies were performed with membrane fouling simulators (MFSs) containing a reverse osmosis (RO) membrane and a 31 mil thick feed spacer, commonly applied in practice in RO and nanofiltration (NF) spiral-wound membrane modules. Numerical modeling studies were done with identical feed spacer geometry differing in thickness (28, 31 and 34 mil). Additionally, experiments were done applying a forward osmosis (FO) membrane with varying spacer thickness (28, 31 and 34 mil), addressing the permeate flux decline and biofilm development. Assessed were the development of feed channel pressure drop (MFS studies), permeate flux (FO studies) and accumulated biomass amount measured by adenosine triphosphate (ATP) and total organic carbon (TOC). Our studies showed that the organic nutrient load determined the accumulated amount of biomass. The same amount of accumulated biomass was found at constant nutrient load irrespective of linear flow velocity, shear, and/or feed spacer thickness. The impact of the same amount of accumulated biomass on feed channel pressure drop and permeate flux was influenced by membrane process design and operational conditions. Reducing the nutrient load by pretreatment slowed-down the biofilm formation. The impact of accumulated biomass on membrane performance was reduced by applying a lower crossflow velocity and/or a thicker and/or a modified geometry feed spacer. The results indicate that cleanings can be delayed

  1. The Impact of Trade Balance in the Current Account of Kosovo’s Balance of Payments

    National Research Council Canada - National Science Library

    Safet Merovci; Edona Sekiraça

    2014-01-01

    .... According to the Balance of Payments Statistics (BOP), the trade balance of goods is the largest component, expressed in absolute and relative terms and consequently it determines the behavior of the current account balance...

  2. The impact of current tobacco use on the outcome of paracetamol poisoning

    DEFF Research Database (Denmark)

    Schmidt, L E; Dalhoff, K

    2003-01-01

    , the effect of current tobacco use on the morbidity and mortality from paracetamol-induced hepatotoxicity. METHODS: A retrospective study was carried out on the basis of the hospital charts of 602 patients admitted with single-dose paracetamol poisoning for whom information on current tobacco use...... was available. RESULTS: In patients admitted with paracetamol poisoning, the rate of current daily tobacco use of 70% (424 of 602 patients) was considerably higher than the rate of 31% in the background population (chi-squared test: P ...: Current tobacco use was very frequent in patients admitted with paracetamol poisoning. It was an independent risk factor of severe hepatotoxicity, acute liver failure and death following paracetamol overdose....

  3. The impact of current tobacco use on the outcome of paracetamol poisoning

    DEFF Research Database (Denmark)

    Schmidt, L E; Dalhoff, K

    2003-01-01

    BACKGROUND: Tobacco smoke contains a number of substances that are capable of inducing cytochrome P450. Consequently, current tobacco use may enhance the hepatotoxicity from a paracetamol overdose by increasing the oxidative metabolism of paracetamol. AIM: To evaluate, by multivariate analysis......, the effect of current tobacco use on the morbidity and mortality from paracetamol-induced hepatotoxicity. METHODS: A retrospective study was carried out on the basis of the hospital charts of 602 patients admitted with single-dose paracetamol poisoning for whom information on current tobacco use...... was available. RESULTS: In patients admitted with paracetamol poisoning, the rate of current daily tobacco use of 70% (424 of 602 patients) was considerably higher than the rate of 31% in the background population (chi-squared test: P tobacco use was an independent risk factor...

  4. Tilt-shift eddy current probe impact on information value of response signal

    OpenAIRE

    Chudacik Vladimir; Smetana Milan

    2016-01-01

    This article deals with the possibility for increasing of the informational value of a response signal using tilt-shift eddy current probe. Numerical simulations based on the FEM method using the OPERA 3D software as well as gained experimental results are presented. The simulated cracks are evaluated at the selected eddy current probe tilts and shifts with respect to conductive plate to obtain additional data needed for its evaluation and localization. Obtained simulation results are compare...

  5. Thermal Impact Analysis of Circulating Current in High Power Modular Online Uninterruptible Power Supplies Application

    DEFF Research Database (Denmark)

    Zhang, Chi; Guerrero, Josep M.; Vasquez, Juan Carlos

    2015-01-01

    . In order to reduce system size and cost, each module shares the same DC and AC bus without any isolation or passive elements in the system. Consequently, potential zero-sequence current is possible to occur and should be paid specific attention. In this paper, a four-module online UPS system is designed....... And thermal and loss distribution condition are investigated under different circulating current condition with conventional three phase H-bridge topology....

  6. Impact of AT2-receptor stimulation on vascular biology, kidney function, and blood pressure

    DEFF Research Database (Denmark)

    Danyel, L.A.; Schmerler, P.; Paulis, L.;

    2013-01-01

    angiotensin II) and with relevance for blood pressure (BP) regulation or hypertensive end-organ damage. These data will include studies on vasodilation/vasoconstriction in isolated resistance arteries ex vivo, studies on kidney function, studies on vascular remodeling, and studies that measured the net effect...... to attenuate hypertension-induced vascular remodeling and reduce arterial stiffening, which in more chronic settings and together with the natriuretic effect may result in modest lowering of BP. We conclude from these preclinical data that AT2R agonists are not suitable for antihypertensive monotherapy...

  7. IMPACTS OF HISTORIC AND CURRENT-USE CHEMICALS IN WESTERN NATIONAL PARKS

    Science.gov (United States)

    The Western Airborne Contaminants Assessment Project (WACAP) is an interagency effort to determine if airborne contaminants such as semi-volatile organic compounds (sacs) and metals(e.g. mercury) are impacting National Parks in the western United States. Remote, high elev...

  8. Impact of neutrino properties on the estimation of inflationary parameters from current and future observations

    CERN Document Server

    Gerbino, Martina; Vagnozzi, Sunny; Lattanzi, Massimiliano; Mena, Olga; Giusarma, Elena; Ho, Shirley

    2016-01-01

    We study the impact of assumptions about neutrino properties on the estimation of inflationary parameters from cosmological data, with a specific focus on the allowed contours in the $n_s/r$ plane. We study the following neutrino properties: (i) the total neutrino mass $ M_\

  9. The global impact of ozone on agricultural crop yields under current and future air quality legislation

    NARCIS (Netherlands)

    Dingenen, van R.; Dentener, F.J.; Raes, F.; Krol, M.C.; Emberson, L.; Cofala, J.

    2009-01-01

    In this paper we evaluate the global impact of surface ozone on four types of agricultural crop. The study is based on modelled global hourly ozone fields for the year 2000 and 2030, using the global 1°×1° 2-way nested atmospheric chemical transport model (TM5). Projections for the year 2030 are bas

  10. Mitigation of the impact of transformer inrush current on voltage sag by TCSC

    Energy Technology Data Exchange (ETDEWEB)

    Khederzadeh, Mojtaba [Department of Electrical Engineering, Power and Water University of Technology, Tehran (Iran)

    2010-09-15

    Thyristor Controlled Series Capacitor (TCSC) as a dynamic system, besides its capability in increasing power transfer in transmission lines, can be used to enhance different power system issues. In this paper, the effect of TCSC on voltage sag following transformer inrush current is investigated. It is shown that excessive transient inrush current occurring during transformer energizing can be mitigated by TCSC. Hence, voltage sag as one of the key components of the power quality is alleviated for the sensitive loads that are connected to the same bus which the power transformer is energized from. During a fault, TCSC can improve the voltage sag by limiting the current and help to keep the voltage as high as possible. Moreover, the inrush currents and the associated voltage sags that usually occur after clearing heavy single- or multistage faults are mitigated by the presence of TCSC. The model used for simulating inrush current is based on the characteristics of the major hysteresis loop out of which the internal trajectories are defined using the translation principal and a linear compensation to generate closed loops. An arctangent relation between the flux and the exciting current is defined. The expression parameters are deduced by curve fitting empirical data defining the major loop or the single-valued saturation characteristic. (author)

  11. Current status of the impact theory for the terminal Cretaceous extinction

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, W.; Alvarez, L.W.; Asaro, F.; Michel, H.V.

    1982-06-01

    Iridium is depleted in the earth's crust relative to its normal solar system abundance. Several hundred measurements by at least seven laboratories have disclosed an iridium abundance anomaly at the Cretaceous-Tertiary (C-T) boundary in 36 sites worldwide. Discovery of the first iridium anomaly in non-marine sediments, by Charles Orth and his colleagues, shows that the iridium was not extracted from sea water. Sediment starvation and a nearby supernova have also been eliminated as possible sources. Impact of a large extraterrestrial object is now widely accepted as the best explanation of the iridium anomaly. Paleomagnetic reversal stratigraphy of four marine and five non-marine C-T boundary sections is consistent with simultaneous extinction worldwide, but does not prove it. Ultra-high-resolution stratigraphic studies at Caravaca, in southern Spain, by Jan Smit, give an unparalled record of the extinction of the planktic foraminifera and the associated geochemical patterns. Au/Ir and Pt/Ir ratios from two C-T boundary clays indicate a type I carbonaceous chondrite composition for the impacting object. Iridium anomalies are known from two other stratigraphic horizons, in each case associated with direct evidence for an extraterrestrial impact: in the Pliocene, with chondritic ablation debris, and in the late Eocene with microtektites. The C-T impact site has not been located. Two interesting candidate sites are the circular sea-floor features west of Portugal and the Deccan Traps of India. There is a 20% probability that impact occurred on sea floor that has subsequently been subducted. The killing mechanism has not yet been established, but both temperature changes and darkness due to atmospheric dust are probable contributors. Darkness would have lasted a few months, rather than our originally suggested few years.

  12. Randomized trial evaluating the framing of cardiovascular risk and its impact on blood pressure control [ISRCTN87597585

    Directory of Open Access Journals (Sweden)

    Peters Tim J

    2001-10-01

    Full Text Available Abstract Background The format or frame in which the results of randomized trials are presented has been shown to influence health professional's self-reported practice. We sought to investigate the effect of framing cardiovascular risk as two different formats in a randomized trial. Methods We recruited 457 patients aged between 60 and 79 years with high blood pressure from 20 family practices in Avon, UK. Patients were randomized to cardiovascular risk presented either as 1 an absolute risk level (AR or as 2 the number needed to treat to prevent an adverse event (NNT. The main outcome measures were: 1 percentage of patients in each group with a five-year cardiovascular risk ≥ 10%, 2 systolic and diastolic blood pressure, 3 intensity of prescribing of cardiovascular medication. Results Presenting cardiovascular risk as either an AR or NNT had no impact reducing cardiovascular risk at 12 month follow up, adjusted odds ratio 1.53 (95%CI 0.76 to 3.08. There was no difference between the two groups in systolic (adjusted difference 0.97 mmHg, 95%CI -2.34 mmHg to 4.29 mmHg or diastolic (adjusted difference 0.70 mmHg, 95%CI -1.05 mmHg to 2.45 mmHg blood pressure. Intensity of prescribing of blood pressure lowering drugs was not significantly different between the two groups at six months follow up. Conclusions Presenting cardiovascular risk in clinical practice guidelines as either an AR or NNT had a similar influence on patient outcome and prescribing intensity. There is no difference in patient outcomes when these alternative formats of risk are used in clinical practice guidelines.

  13. Variability at Multiple Scales: Using an Array of Current and Pressure Sensor Equipped Inverted Echo Sounders to Measure the Ocean

    Science.gov (United States)

    2016-11-29

    infer full- water column density profiles (&p/&z), and horizontal gradients in -r have been used to infer velocity-shear using the thermal wind...sit on the seafloor in a rigid anchor stand in water depths D ranging between 500 and 6700 m. The current sensor is tethered to the glass sphere...reflectors are detected (e.g., the air-sea interface is detected, whereas the pycnocline within the water column is not). Subsurface echoes that arrive

  14. Routine enema before urodynamics has no impact on the quality of abdominal pressure curves: Results of a prospective controlled study.

    Science.gov (United States)

    Rigole, H; Senal, N; Damphousse, M; Brochard, C; Manunta, A; Kerdraon, J; Tondut, L; Alimi, Q; Hascoet, J; Siproudhis, L; Peyronnet, B; Bonan, I

    2016-12-01

    The presence of stools in the rectum might affect the quality of the abdominal pressure curve during filling cystometry, but, to date, no study has evaluated the impact of bowel preparation before urodynamics. We evaluated the influence of a sodium phosphate enema before urodynamics on the quality of the abdominal pressure curve. A prospective, controlled, single-blind study was conducted in a single center from May to June 2013. The patients were divided into 2 consecutive groups: patients seen in outpatient clinics during the first 6 weeks (group A) who underwent urodynamics without bowel preparation and patients seen in outpatient clinics during the second 6 weeks (group B) who had a prescription of sodium phosphate enema before urodynamics. The primary endpoint was the quality of the abdominal pressure curve evaluated independently by three physicians who were blinded to the study group. The following data were also collected: age, gender, the presence of a neurological disorder, complicated nature of urodynamics and bother related to preparation for it, assessed using a Likert scale (0 to 10), and the equipment used. A per protocol analysis and an intent-to-treat analysis were conducted. One hundred and thirty-nine patients were included: 54 in group A and 85 in group B. One-third of patients had neurological conditions. 14 patients in group B did not perform their scheduled enema. Thus, 68 patients performed an enema before urodynamics and 71 did not. There was no difference between groups A and B regarding the complicated nature of urodynamics (Likert scale: 3.12 vs. 3.18; P=0.91) or bother related to preparation for it (Likert scale: 3.46 vs. 2.97; P=0.43). In the per protocol analysis, the abdominal pressure curve was considered perfectly interpretable (PI) in 69% of patients who did not receive an enema before urodynamics and in 65% of patients who did (P=0.61). The between-group difference was not statistically significant in intent-to-treat analysis (P

  15. [Impact of intracameral pressure on donor cut angles in nonmechanical Er:YAG laser trephination for penetrating keratoplasty].

    Science.gov (United States)

    Sauer, Renate; Seitz, Berthold; Mardin, Christian; Langenbucher, Achim; Hofmann-Rummelt, Carmen; Viestenz, Anja; Küchle, Michael; Naumann, Gottfried O H

    2003-06-01

    Congruent cut surfaces are a predisposition for good apposition of donor and recipient during penetrating keratoplasty (PK). The purpose of this study was to assess the impact of the intracameral pressure during nonmechanical donor trephination from the epithelial side on the cut angles for experimental human PK. With a Q-switched 2.94 micro m Er : YAG laser a 6 mm sized corneal donor trephination was performed subtotally in 30 human corneas using an artificial anterior chamber device allowing different intracameral pressures (10, 20, and 40 mm Hg). The cut angles were measured immediately after the trephination by ultrasound biomicroscopy (UBM) at four quadrants: between trephination cut and corneal epithelium (angle 1 = A1-UBM) and between trephination cut and horizontal plane (angle 2 = A2-UBM). The positions of the measures were marked, the corneas were fixed in a buffered 10 % paraformaldehyde solution, and the same positions were analyzed by histology. The histological cuts were digitized, the images printed, and the cut angles measured in paper (A1-histology). Mean angles were 111.6 degrees /113.5 degrees /126.6 degrees (A1-UBM), 88.4 degrees /93.5 degrees /101.8 degrees (A2-UBM) and 120.4 degrees /125.1 degrees /119.3 degrees (A1-histology) with 10/20/40 mm Hg, respectively. The A2-UBM showed a significant increase of divergence with increasing intracameral pressure (p 0.09). Increasing intracameral pressure using an artificial anterior chamber during donor trephination from the epithelial side for nonmechanical PK using Er : YAG laser results in increasing divergence of cut angles. This may disturb the congruence of the cut angles in donor-recipient apposition. To achieve standardised cut angles for a good donor recipient apposition, similar normotonic intracameral pressures for donor and recipient trephination should be attempted. The UBM has the potential to analyse the cut angle immediately after subtotal trephination preserving the attempted

  16. The Analysis of Fluid Pressure Impact on String Force and Deformation in Oil and Gas Wells

    Directory of Open Access Journals (Sweden)

    Gao Baokui

    2015-01-01

    Full Text Available Fluid pressure is a crucial factor to tubular string strength and deformation in oil and gas wells, and it is the most difficult factor to deal with. When the string constrained by downhole tools, such as packers, action pattern of fluid on string is changed. Calculation methods of string stress and deformation given by engineering handbooks doesn’t distinguish these issues in detail. So mistakes are often made when these methods are used. Tangled concepts lead to large calculation error. In this paper, the influence of fluid pressure on string axial force and deformation, buoyancy treatment in packed condition, are discussed roundly both in vertical wells and directional wells. Practical calculating method of string axial force through the hook load is presented, and element buoyancy in different borehole trajectory is given. It is found that the traditional simplified buoyancy coefficient method, which is used to calculate string axial force and axial extension, can only be used in vertical wells with tubular string suspended freely, because in this condition buoyancy acts on the bottom of string. If the string is constrained by downhole tools, such as packer or anchor, buoyancy could not be treated as usual. In directional well the buoyancy not only changes string axial force but induces shear stress in string cross section. When calculating the influence of fluid on string, operation sequence and constraints from borehole and downhole tools should be considered comprehensively.

  17. The Impact of Ocular Pressures, Material Properties and Geometry on Optic Nerve Head Deformation

    Science.gov (United States)

    Feola, Andrew J.; Myers, Jerry G.; Raykin, Julia; Nelson, Emily S.; Samuels, Brian C.; Ethier C. Ross

    2017-01-01

    Alteration in intracranial pressure (ICP) has been associated with various diseases that cause visual impairment, including glaucoma, idiopathic intracranial hypertension and Visual Impairment and Intracranial Pressure (VIIP) syndrome. However, how changes in ICP lead to vision loss is unclear, although it is hypothesized to involve deformations of the tissues in the optic nerve head (ONH). Recently, understanding the effect of ICP alterations on ocular tissues has become a major concern for NASA, where 42 of astronauts that partake in long duration space missions suffer from VIIP syndrome. Astronauts with VIIP syndrome suffer from visual impairment and changes in ocular anatomy that persist after returning to earth (1). It is hypothesized that the cephalad fluid shift that occurs upon entering microgravity increases ICP, which leads to an altered biomechanical environment in the posterior globe and optic nerve sheath, and subsequently VIIP syndrome. Our goal was to develop a finite element (FE) model to simulate the acute effects of elevated ICP on the posterior eye. Here, we simulated how inter-individual differences affect the deformation of ONH tissues. Further, we examined how several different geometries influenced deformations when exposed to elevated ICP.

  18. Impacts of Changes of Indoor Air Pressure and Air Exchange Rate in Vapor Intrusion Scenarios.

    Science.gov (United States)

    Shen, Rui; Suuberg, Eric M

    2016-02-01

    There has, in recent years, been increasing interest in understanding the transport processes of relevance in vapor intrusion of volatile organic compounds (VOCs) into buildings on contaminated sites. These studies have included fate and transport modeling. Most such models have simplified the prediction of indoor air contaminant vapor concentrations by employing a steady state assumption, which often results in difficulties in reconciling these results with field measurements. This paper focuses on two major factors that may be subject to significant transients in vapor intrusion situations, including the indoor air pressure and the air exchange rate in the subject building. A three-dimensional finite element model was employed with consideration of daily and seasonal variations in these factors. From the results, the variations of indoor air pressure and air exchange rate are seen to contribute to significant variations in indoor air contaminant vapor concentrations. Depending upon the assumptions regarding the variations in these parameters, the results are only sometimes consistent with the reports of several orders of magnitude in indoor air concentration variations from field studies. The results point to the need to examine more carefully the interplay of these factors in order to quantitatively understand the variations in potential indoor air exposures.

  19. Aquifer imaging with pressure waves—Evaluation of low-impact characterization through sandbox experiments

    Science.gov (United States)

    Zhou, YaoQuan; Lim, David; Cupola, Fausto; Cardiff, Michael

    2016-03-01

    Understanding the detailed spatial variation of hydraulic properties in the subsurface has been the subject of intensive research over the past three decades. A recently developed approach to characterize subsurface properties is hydraulic tomography, in which a series of pumping tests are jointly inverted using a heterogeneous numerical model. Recently, Cardiff et al. (2013) proposed a modified tomography approach named Oscillatory Hydraulic Tomography (OHT), in which periodic pumping signals of different frequencies serve as the aquifer stimulation, and pressure responses are recorded at observation locations for tomographic analysis. Its key advantages over traditional hydraulic tomography are that: (1) there is no net injection or extraction of water, and (2) the impulse (an oscillatory signal of known frequency) is easily extracted from noisy data. However, OHT has only been evaluated through numerical experiments to date. In this work, we evaluate OHT performance by attempting to image known heterogeneities in a synthetic aquifer. An instrumented laboratory sandbox is filled with material of known hydraulic properties, and we measure aquifer responses due to oscillatory pumping stimulations at periods of 2, 5, 10, and 20 s. Pressure oscillation time series are processed through Fourier Transforms and inverted tomographically to obtain estimates of aquifer heterogeneity, using a fast, steady-periodic groundwater flow model. We show that OHT is able to provide robust estimates of aquifer hydraulic conductivity even in cases where relatively few pumping tests and observation locations are available. The use of multiple stimulation frequencies is also shown to improve imaging results.

  20. Numerical Analysis of Hydrodynamic Pressure Induced by Fluid-Solid Impact

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    - As a further development of the authors′ work (Huang and Qian, 1993), in this paper a newnumerical method based on the time domain boundary element technique is proposed for solving fluid-sol-id coupling problems, in which a rigid body impacts normally on the calm surface of a half-space fluid. Afundamental solution to the half-space potential flow problem is first derived with the method of images.Then, an equivalent boundary integral equation in the Laplace transform domain is established by meansof Green′s second identity. Through the inverse Laplace transform and discretization in both time andboundary of the fluid region, the numerical calculation for the problem under consideration has been car-ried out. Several examples demonstrate that the present method is more efficient than existing ones, fromwhich it is also seen that the shape of the impacting body has a considerable effect on the total impactforce.

  1. Current situation and suggestions for pressure ulcer management in China%我国压疮管理现状与建议

    Institute of Scientific and Technical Information of China (English)

    张洪君; 卢㛃; 刘金莲

    2014-01-01

    Pressure ulcer is a common and important complication in clinical nursing. Its mechanism is complicated. Pressure ulcer widely exists in different departments of hospital and would greatly inlfuence patients. This paper summarized and analyzed the current situation of pressure ulcer management in China. The ideas and methods of pressure ulcer management from abroad had been applied in some medical institutions in China, and were modiifed in order to ift themselves. But due to the diversity of our medical institutions, we still need to formulate a uniifed nursing standard to improve the prevention and treatment management of pressure ulcer in our country.%压疮是临床护理工作中常见的重要并发症,其发生机制复杂,广泛存在于各科室,给患者带来较大影响。本文通过对目前我国压疮管理现状的分析发现,国际压疮护理管理理念和方法已经在我国部分医疗机构得到改进和应用,逐步形成适合我国的压疮防治规范。但是,由于我国各地医疗机构水平参差不齐,为提高全国整体压疮预防与治疗管理水平,还须制订统一的全国压疮护理标准。

  2. The Impact of Tax Pressure on Companies’ Performance Case Study: OECD Europe Zone

    OpenAIRE

    Georgeta VINTILA; Ioana Laura TIBULCA

    2013-01-01

    There are many factors that influence managers' confidence in the business environment. Of all these factors of influence, the impact of taxation on business performance is the subject of the present study. To analyze how taxation affects the business confidence index, we used data collected for OECD European countries in estimating two different regression models. Our results will show that managers take changes in taxation into account when they anticipate the evolution of the business envi...

  3. The Impact of Trade Balance in the Current Account of Kosovo’s Balance of Payments

    Directory of Open Access Journals (Sweden)

    Safet Merovci

    2014-02-01

    Full Text Available The trade deficit and specifically the current account deficit are the main challenges that Kosovo‘s economy is facing. According to the Balance of Payments Statistics (BOP, the trade balance of goods is the largest component, expressed in absolute and relative terms and consequently it determines the behavior of the current account balance. Trade deficit to GDP ratio is very high - more than 50 percent. Regarding this, financing the constant deficit of the current account is becoming a real problem, because in the long run it is impossible for a country to spend more than its income without becoming a debtor to the rest of the world. Given the unchanged structure of the current account of the Balance of Payments, we conclude that, an improvement of the trade balance is a precondition to the improvement of the current account balance. This can be done through longterm and sustainable substitution of imports with domestic production and also with effective export promotion. Increasing foreign direct investment and export promotion can be considered, in the longer term, the main way to improve Kosovo's Trade Balance.

  4. Incremental impact of adding boys to current human papillomavirus vaccination programs: role of herd immunity.

    Science.gov (United States)

    Brisson, Marc; van de Velde, Nicolas; Franco, Eduardo L; Drolet, Mélanie; Boily, Marie-Claude

    2011-08-01

    Our aim was to examine the potential incremental impact of vaccinating boys against human papillomavirus (HPV) on vaccine-type infection in females and males, using an individual-based HPV transmission-dynamic model. Under base assumptions (vaccine efficacy = 99%, duration of protection = 20 years, coverage = 70%), vaccinating 12-year-old boys, in addition to girls, resulted in an incremental reduction in HPV-16/18 (HPV-6/11) incidence over 70 years of 16% (3%) in females and 23% (4%) in males. The benefit of vaccinating boys decreased with improved vaccination coverage in girls. Given the important predicted herd immunity impact of vaccinating girls under moderate to high vaccine coverage, the potential incremental gains of vaccinating boys are limited.

  5. Impact and cost-effectiveness of current and future tuberculosis diagnostics: the contribution of modelling

    Science.gov (United States)

    Houben, R.; Cohen, T.; Pai, M.; Cobelens, F.; Vassall, A.; Menzies, N. A.; Gomez, G. B.; Langley, I.; Squire, S. B.; White, R.

    2014-01-01

    SUMMARY The landscape of diagnostic testing for tuberculosis (TB) is changing rapidly, and stakeholders need urgent guidance on how to develop, deploy and optimize TB diagnostics in a way that maximizes impact and makes best use of available resources. When decisions must be made with only incomplete or preliminary data available, modelling is a useful tool for providing such guidance. Following a meeting of modelers and other key stakeholders organized by the TB Modelling and Analysis Consortium, we propose a conceptual framework for positioning models of TB diagnostics. We use that framework to describe modelling priorities in four key areas: Xpert® MTB/RIF scale-up, target product profiles for novel assays, drug susceptibility testing to support new drug regimens, and the improvement of future TB diagnostic models. If we are to maximize the impact and cost-effectiveness of TB diagnostics, these modelling priorities should figure prominently as targets for future research. PMID:25189546

  6. Adjustable box-wing model for solar radiation pressure impacting GPS satellites

    Science.gov (United States)

    Rodriguez-Solano, C. J.; Hugentobler, U.; Steigenberger, P.

    2012-04-01

    One of the major uncertainty sources affecting Global Positioning System (GPS) satellite orbits is the direct solar radiation pressure. In this paper a new model for the solar radiation pressure on GPS satellites is presented that is based on a box-wing satellite model, and assumes nominal attitude. The box-wing model is based on the physical interaction between solar radiation and satellite surfaces, and can be adjusted to fit the GPS tracking data. To compensate the effects of solar radiation pressure, the International GNSS Service (IGS) analysis centers employ a variety of approaches, ranging from purely empirical models based on in-orbit behavior, to physical models based on pre-launch spacecraft structural analysis. It has been demonstrated, however, that the physical models fail to predict the real orbit behavior with sufficient accuracy, mainly due to deviations from nominal attitude, inaccurately known optical properties, or aging of the satellite surfaces. The adjustable box-wing model presented in this paper is an intermediate approach between the physical/analytical models and the empirical models. The box-wing model fits the tracking data by adjusting mainly the optical properties of the satellite's surfaces. In addition, the so called Y-bias and a parameter related to a rotation lag angle of the solar panels around their rotation axis (about 1.5° for Block II/IIA and 0.5° for Block IIR) are estimated. This last parameter, not previously identified for GPS satellites, is a key factor for precise orbit determination. For this study GPS orbits are generated based on one year (2007) of tracking data, with the processing scheme derived from the Center for Orbit Determination in Europe (CODE). Two solutions are computed, one using the adjustable box-wing model and one using the CODE empirical model. Using this year of data the estimated parameters and orbits are analyzed. The performance of the models is comparable, when looking at orbit overlap and orbit

  7. The impact of current alternative herbal remedies on dental patient management.

    Science.gov (United States)

    Karimi, K

    1999-01-01

    With the recent boom in holistic and herbal medicine and an ever-growing trend among the general population to refer to herbal remedies as an alternative to traditional pharmaceutical therapies, dental health care providers must be aware of the wide consumption of such products and understand their nature. It becomes imperative, therefore, to include questions regarding the use of herbal preparations as a matter of routine in the patient's drug history, since this may impact a safe dental patient care delivery.

  8. Tilt-shift eddy current probe impact on information value of response signal

    Directory of Open Access Journals (Sweden)

    Chudacik Vladimir

    2016-03-01

    Full Text Available This article deals with the possibility for increasing of the informational value of a response signal using tilt-shift eddy current probe. Numerical simulations based on the FEM method using the OPERA 3D software as well as gained experimental results are presented. The simulated cracks are evaluated at the selected eddy current probe tilts and shifts with respect to conductive plate to obtain additional data needed for its evaluation and localization. Obtained simulation results are compared and discussed with the experimental results.

  9. Thermal Impact Analysis of Circulating Current in High Power Modular Online Uninterruptible Power Supplies Application

    DEFF Research Database (Denmark)

    Zhang, Chi; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    In modular uninterruptible power supplies (UPSs), several DC/AC modules are required to work in parallel. This structure allows the system to be more reliable and flexible. These DC/AC modules share the same DC bus and AC critical bus. Module differences, such as filter inductor, filter capacitor......, control parameters, and so on, will make it possible for the potential zero sequence current to flow among the modules. This undesired type of circulating current will bring extra losses to the power semiconductor devices in the system, which should be paid special attention in high power application...

  10. Impact of climate change and anthropogenic pressure on the water resources of India: challenges in management

    Directory of Open Access Journals (Sweden)

    K. Shadananan Nair

    2016-10-01

    Full Text Available Freshwater resources of India are getting fast degraded and depleted from the changing climate and pressure of fast rising population. Changing intensity and seasonality of rainfall affect quantity and quality of water. Most of the rivers are polluted far above safety limits from the untreated domestic, industrial and agricultural effluents. Changes in the intensity, frequency and tracks of storms salinate coastal aquifers. Aquifers are also under the threat from rising sea level. Groundwater in urban limits and industrial zones are far beyond safety limits. Large-scale destruction of wetlands for industries and residential complexes has affected the quality of surface and groundwater resources in most parts of India. Measures to maintain food security and the new developments schemes such as river linking will further deteriorate the water resources. Falling water availability leads to serious health issues and various socio-economic issues. India needs urgent and appropriate adaptation strategies in the water sector.

  11. Impact of climate change and anthropogenic pressure on the water resources of India: challenges in management

    Science.gov (United States)

    Shadananan Nair, K.

    2016-10-01

    Freshwater resources of India are getting fast degraded and depleted from the changing climate and pressure of fast rising population. Changing intensity and seasonality of rainfall affect quantity and quality of water. Most of the rivers are polluted far above safety limits from the untreated domestic, industrial and agricultural effluents. Changes in the intensity, frequency and tracks of storms salinate coastal aquifers. Aquifers are also under the threat from rising sea level. Groundwater in urban limits and industrial zones are far beyond safety limits. Large-scale destruction of wetlands for industries and residential complexes has affected the quality of surface and groundwater resources in most parts of India. Measures to maintain food security and the new developments schemes such as river linking will further deteriorate the water resources. Falling water availability leads to serious health issues and various socio-economic issues. India needs urgent and appropriate adaptation strategies in the water sector.

  12. THE ADSORPTION OF STARCHES ON PRESSURE-SENSITIVE ADHESIVE MATERIAL AND ITS IMPACT ON AGGLOMERATION

    Institute of Scientific and Technical Information of China (English)

    Xin Huo; Richard A.Venditti; Houmin Chang

    2004-01-01

    Pressure sensitive adhesive (PSA) particles, or stickies, will self-agglomerate in water with agitation.Under certain conditions, it was found that some starches and Poly-Diallyldimethylammonium Chloride prevent this agglomeration. Both cationic and neutral starches were found to adsorb onto the surface of the negatively charged stickies. This was determined by infra-red spectroscopy, UV spectroscopy, contact angle measurements and charge titration methods. Cationic charge promotes the adsorption of starch onto the surface of stickies and cationic starches adsorbed on the PSA film do not desorb when exposed for 15 minutes to deionized water at room temperature. Cationic starches were found to prevent the agglomeration of stickies at lower concentrations relative to neutral starches.Stickies compete with fibers for the cationic charge in the system. Over the molecular weight (MW)range studied, the MW of the starch has no effect on the prevention of agglomeration of stickies.

  13. Impact of obesity on kidney function and blood pressure in children.

    Science.gov (United States)

    Ding, Wei; Cheung, Wai W; Mak, Robert H

    2015-05-06

    In recent years, obesity has become an increasingly important epidemic health problem in children and adolescents. The prevalence of the overweight status in children grew from 5% to 11% from 1960s to 1990s. The epidemic of obesity has been paralleled by an increase in the incidence of chronic kidney disease (CKD) and hypertension. Results of several studies have demonstrated that obesity and metabolic syndrome were independent predictors of renal injury. The pathophysiology of obesity related hypertension is complex, including activation of sympathetic nervous system, renin angiotensin aldosterone system, hyperinsulinemia and inflammation. These same mechanisms likely contribute to the development of increased blood pressure in children. This review summarizes the recent epidemiologic data linking obesity with CKD and hypertension in children, as well as the potential mechanisms.

  14. Impact of sodium–glucose cotransporter 2 inhibitors on blood pressure

    Directory of Open Access Journals (Sweden)

    Reed JW

    2016-10-01

    Full Text Available James W Reed Morehouse School of Medicine, Atlanta, GA, USA Abstract: SGLT2 inhibitors are glucose-lowering agents used to treat type 2 diabetes mellitus (T2DM. These agents target the kidney to promote urinary glucose excretion, resulting in improved blood glucose control. SGLT2-inhibitor therapy is also associated with weight loss and blood pressure (BP lowering. Hypertension is a common comorbidity in patients with T2DM, and is associated with excess morbidity and mortality. This review summarizes data on the effect of SGLT2 inhibitors marketed in the US (namely canagliflozin, dapagliflozin, or empagliflozin on BP in patients with T2DM. Boolean searches were conducted that included terms related to BP or hypertension with terms for SGLT2 inhibitors, canagliflozin, dapagliflozin, or empagliflozin using PubMed, Google, and Google Scholar. Data from numerous randomized controlled trials of SGLT2 inhibitors in patients with T2DM demonstrated clinically relevant reductions in both systolic and diastolic BP, assessed via seated office measurements and 24-hour ambulatory BP monitoring. Observed BP lowering was not associated with compensatory increases in heart rate. Circadian BP rhythm was also maintained. The mechanism of SGLT2 inhibitor-associated BP reduction is not fully understood, but is assumed to be related to osmotic diuresis and natriuresis. Other factors that may also contribute to BP reduction include SGLT2 inhibitor-associated decreases in body weight and reduced arterial stiffness. Local inhibition of the renin–angiotensin–aldosterone system secondary to increased delivery of sodium to the juxtaglomerular apparatus during SGLT2 inhibition has also been postulated. Although SGLT2 inhibitors are not indicated as BP-lowering agents, the modest decreases in systolic and diastolic BP observed with SGLT2 inhibitors may provide an extra clinical advantage for the majority of patients with T2DM, in addition to improving blood glucose

  15. Performance of water and hybrid stabilized electric arcs: the impact of dependence of radiation losses and plasma density on pressure

    Science.gov (United States)

    Jeništa, J.; Bartlová, M.; Aubrecht, V.

    2006-10-01

    Processes in the worldwide unique type of thermal plasma generator with water vortex stabilization and combined stabilization of arc by argon flow and water vortex have been numerically studied. Two-dimensional axisymmetric numerical model assumes laminar and compressible plasma flow in the state of local thermodynamic equilibrium. The calculation domain includes the arc discharge area between the near-cathode region and the outlet nozzle of the plasma torch. Radiation losses from the arc are calculated by the partial characteristics method for atmospheric pressure water and argon-water discharges. Thermal, electrical and fluid-dynamic characteristics of such arcs have been studied for the range of currents 150÷600 A under the assumption that radiation losses and plasma density depend linearly on pressure. It was proved that, taking this dependence into account, plasma velocity decrease while power losses from the arc by radiation and radial conduction increase with current. Outlet plasma temperature as well as electric potential drop remain practically unchanged.

  16. Current and planned numerical development for improving computing performance for long duration and/or low pressure transients

    Energy Technology Data Exchange (ETDEWEB)

    Faydide, B. [Commissariat a l`Energie Atomique, Grenoble (France)

    1997-07-01

    This paper presents the current and planned numerical development for improving computing performance in case of Cathare applications needing real time, like simulator applications. Cathare is a thermalhydraulic code developed by CEA (DRN), IPSN, EDF and FRAMATOME for PWR safety analysis. First, the general characteristics of the code are presented, dealing with physical models, numerical topics, and validation strategy. Then, the current and planned applications of Cathare in the field of simulators are discussed. Some of these applications were made in the past, using a simplified and fast-running version of Cathare (Cathare-Simu); the status of the numerical improvements obtained with Cathare-Simu is presented. The planned developments concern mainly the Simulator Cathare Release (SCAR) project which deals with the use of the most recent version of Cathare inside simulators. In this frame, the numerical developments are related with the speed up of the calculation process, using parallel processing and improvement of code reliability on a large set of NPP transients.

  17. Evidence of current impact of climate change on life : A walk from genes to the biosphere

    NARCIS (Netherlands)

    Penuelas, Josep; Sardans, Jordi; Estiarte, Marc; Ogaya, Roma; Carnicer, Jofre; Coll, Marta; Barbeta, Adria; Rivas-Ubach, Albert; Llusia, Joan; Garbulsky, Martin; Filella, Iolanda; Jump, Alistair S.

    We review the evidence of how organisms and populations are currently responding to climate change through phenotypic plasticity, genotypic evolution, changes in distribution and, in some cases, local extinction. Organisms alter their gene expression and metabolism to increase the concentrations of

  18. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

    NARCIS (Netherlands)

    Gemerden, Barend S. van; Olff, Han; Parren, Marc P.E.; Bongers, Frans

    2003-01-01

    Aim: Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community-wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant

  19. Impact of heating and current drive mix on the ITER hybrid scenario

    NARCIS (Netherlands)

    Citrin, J.; Artaud, J. F.; Garcia, J.; Hogeweij, G. M. D.; Imbeaux, F.

    2010-01-01

    Hybrid scenario performance in ITER is studied with the CRONOS integrated modelling suite, using the GLF23 anomalous transport model for heat transport prediction. GLF23 predicted core confinement is optimized through tailoring the q-profile shape by a careful choice of current drive actuators, affe

  20. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

    NARCIS (Netherlands)

    Gemerden, van B.S.; Olff, H.; Parren, M.P.E.; Bongers, F.J.J.M.

    2003-01-01

    Aim Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community-wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant

  1. The impact of breaks during foundry work of the pressure casting machine on casting quality

    Directory of Open Access Journals (Sweden)

    S. Borkowski

    2010-10-01

    Full Text Available The result in the appearance of the technical object damage are its failures, which are considered as the most important causes of productivity loss in the technical objects. The article introduces main types of losses resulting from the downtimes of a casting machine. The time impact analysis of the font mould failure and the remaining time of the machine's failures on the castings quality was conducted. The failure time structure of the font mould and other failures of the machine was presented.

  2. The impact of continuous non-invasive arterial blood pressure monitoring on blood pressure stability during general anaesthesia in orthopaedic patients: A randomised trial.

    Science.gov (United States)

    Meidert, Agnes S; Nold, Johanna S; Hornung, Roman; Paulus, Alexander C; Zwißler, Bernhard; Czerner, Stephan

    2017-11-01

    In patients undergoing general anaesthesia, intraoperative hypotension occurs frequently and is associated with adverse outcomes such as postoperative acute kidney failure, myocardial infarction or stroke. A history of chronic hypertension renders patients more susceptible to a decrease in blood pressure (BP) after induction of general anaesthesia. As a patient's BP is generally monitored intermittently via an upper arm cuff, there may be a delay in the detection of hypotension by the anaesthetist. The current study investigates whether the presence of continuous BP monitoring leads to improved BP stability. Randomised, controlled and single-centre study. A total of 160 orthopaedic patients undergoing general anaesthesia with a history of chronic hypertension. The patients were randomised to either a study group (n = 77) that received continuous non-invasive BP monitoring in addition to oscillometric intermittent monitoring, or a control group (n = 83) whose BP was monitored intermittently only. The interval for oscillometric measurements in both groups was set to 3 min. After induction of general anaesthesia, oscillometric BP values of the two groups were compared for the first hour of the procedure. Anaesthetists were blinded to the purpose of the study. BP stability and hypotensive events. There was no difference in baseline BP between the groups. After adjustment for multiple testing, mean arterial BP in the study group was significantly higher than in the control group at 12 and 15 min. Mean ± SD for study and control group, respectively were: 12 min, 102 ± 24 vs. 90 ± 26 mmHg (P = 0.039) and 15 min, 102 ± 21 vs. 90 ± 23 mmHg (P = 0.023). Hypotensive readings below a mean pressure of 55 mmHg occurred more often in the control group (25 vs. 7, P = 0.047). Continuous monitoring contributes to BP stability in the studied population. NCT02519101.

  3. Optimization study on pin tip diameter of an impact-pin nozzle at high pressure ratio

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, C. Palani; Lee, Kwon Hee [FMTRC, Daejoo Machinery Co. Ltd., Daegu (Korea, Republic of); Park, Tae Choon; Cha, Bong Jun [Engine Components Research Team, Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Kim, Heuy Dong [Dept. of Mechanical Engineering, Andong National University, Andong (Korea, Republic of)

    2016-09-15

    Wet compression system is typically installed in a gas turbine engine to increase the net power output and efficiency. A crucial component of the wet compression system is the nozzle which generates fine water droplets for injection into the compressor. The main objective of present work is to optimize a kind of nozzle called impact-pin spray nozzle and thereby produce better quality droplets. To achieve this, the dynamics occurring in the water jet impinging on the pin tip, the subsequent formation of water sheet, which finally breaks into water droplets, must be studied. In this manuscript, the progress on the numerical studies on impact-pin nozzle are reported. A small computational domain covering the orifice, pin tip and the region where primary atomization occurs is selected for numerical analysis. The governing equations are selected in three dimensional cartesian form and simulations are performed to predict the dynamics of water jet impinging on the pin. Systematic studies were carried out and the results leading to the choice of turbulence model and the effect of pin tip diameter are reported here. Further studies are proposed to show the future directions of the present research work.

  4. Prolonged high-pressure balloon angioplasty of femoropopliteal lesions:Impact on stent implantation rate and mid-term outcome

    Institute of Scientific and Technical Information of China (English)

    Gianluca Rigatelli; Mariano Palena; Paolo Cardaioli; Fabio dellAvvocata; Massimo Giordan; Dobrin Vassilev; Marco Manzi

    2014-01-01

    Objectives To assess the impact on stent implantation rate and mid-term outcomes of prolonged high pressure angioplasty of femoropopliteal lesions. Methods We retrospectively enrolled 620 consecutive patients from January 2011 to December 2011 (75.6 ±12.3 years, 355 males, 76.5%in Rutherford class 5-6), referred for critical limb ischemia and submitted to prolonged high-pressure angioplasty of femoropopliteal lesions. The definition of prolonged high-pressure angioplasty includes dilation to at least 18 atm for at least 120 s. Proce-dural data, and clinical and instrumental follow-up were analyzed to assess stent implantation rate and mid-term outcomes. Results The preferred approach was ipsilateral femoral antegrade in 433/620 patients (69.7%) and contralateral cross-over in 164/620 (26.4%) and pop-liteal retrograde+femoral antegrade in 23/620 (3.7%). Techniques included subintimal angioplasty in 427/620 patients (68.8%) and endolu-minal angioplasty in 193/620 patients (31.2%). The prolonged high pressure balloon angioplasty procedure was successful in 86.2%(minor intra-procedural complications rate 15.7%), stent implantation was performed in 74 patients (11.9%), with a significant improvement of ankle-brachial index (0.29 ±0.6 vs. 0.88 ±0.3, P<00.1) and Rutherford class (5.3 ±0.8 vs. 0.7 ±1.9, P<0.01), a primary patency rate of 86.7%, restenosis of 18.6%on Doppler ultrasound and a target lesion revascularization of 14.8%at a mean follow-up of 18.1 ±6.4 months (range 1-24 months). Secondary patency rate was 87.7%. Conclusions Prolonged high pressure angioplasty of femoropopliteal lesions appears to be safe and effective allowing for an acceptable patency and restenosis rates on mid-term.

  5. [Problems of work world and its impact on health. Current financial crisis].

    Science.gov (United States)

    Tomasina, Fernando

    2012-06-01

    Health and work are complex processes. Besides, they are multiple considering the forms they take. These two processes are linked to each other and they are influenced by each other. According to this, it is possible to establish that work world is extremely complex and heterogeneous. In this world, "old" or traditional risks coexist with "modern risks", derived from the new models of work organization and the incorporation of new technologies. Unemployment, work relationships precariousness and work risks outsourcing are results of neoliberal strategies. Some negative results of health-sickness process derived from transformation in work world and current global economic crisis have been noticed in current work conditions. Finally, the need for reconstructing policies focusing on this situation derived from work world is suggested.

  6. Impact of transcranial direct current stimulation (tDCS on neuronal functions

    Directory of Open Access Journals (Sweden)

    Suman Das

    2016-11-01

    Full Text Available Transcranial direct current stimulation (tDCS, a noninvasive brain stimulation technique, modulates neuronal excitability by the application of a small electrical current. The low cost and ease of the technique has driven interest in potential clinical applications. However, outcomes are highly sensitive to stimulation parameters, leading to difficulty maximizing the technique’s effectiveness. Although reversing the polarity of stimulation often causes opposite effects, this is not always the case. Effective clinical application will require an understanding of how tDCS works; how it modulates a neuron; how it affects the local network; and how it alters inter-network signaling. We have summarized what is known regarding the mechanisms of tDCS from sub-cellular processing to circuit level communication with a particular focus on what can be learned from the polarity specificity of the effects.

  7. Impact of adaptation currents on synchronization of coupled exponential integrate-and-fire neurons.

    Directory of Open Access Journals (Sweden)

    Josef Ladenbauer

    Full Text Available The ability of spiking neurons to synchronize their activity in a network depends on the response behavior of these neurons as quantified by the phase response curve (PRC and on coupling properties. The PRC characterizes the effects of transient inputs on spike timing and can be measured experimentally. Here we use the adaptive exponential integrate-and-fire (aEIF neuron model to determine how subthreshold and spike-triggered slow adaptation currents shape the PRC. Based on that, we predict how synchrony and phase locked states of coupled neurons change in presence of synaptic delays and unequal coupling strengths. We find that increased subthreshold adaptation currents cause a transition of the PRC from only phase advances to phase advances and delays in response to excitatory perturbations. Increased spike-triggered adaptation currents on the other hand predominantly skew the PRC to the right. Both adaptation induced changes of the PRC are modulated by spike frequency, being more prominent at lower frequencies. Applying phase reduction theory, we show that subthreshold adaptation stabilizes synchrony for pairs of coupled excitatory neurons, while spike-triggered adaptation causes locking with a small phase difference, as long as synaptic heterogeneities are negligible. For inhibitory pairs synchrony is stable and robust against conduction delays, and adaptation can mediate bistability of in-phase and anti-phase locking. We further demonstrate that stable synchrony and bistable in/anti-phase locking of pairs carry over to synchronization and clustering of larger networks. The effects of adaptation in aEIF neurons on PRCs and network dynamics qualitatively reflect those of biophysical adaptation currents in detailed Hodgkin-Huxley-based neurons, which underscores the utility of the aEIF model for investigating the dynamical behavior of networks. Our results suggest neuronal spike frequency adaptation as a mechanism synchronizing low frequency

  8. Structural evaluation of the Shippingport Reactor Pressure Vessel and Neutron Shield Tank package for impact and puncture loads

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, L.E.; Chou, C.K.; Lo, T.; Schwartz, M.W.

    1988-06-01

    A structural evaluation of Shippingport Reactor Pressure Vessel and Neutron Shield Tank package for impact and puncture loads under the normal and hypothetical accident conditions of 10 CFR 71 was performed. Component performance criteria for the Shippingport package and the corresponding structural acceptance criteria for these components were developed based on a review of the package geometry, the planned transport environment, and the external radiation standards and dispersal limits of 10 CFR 71. The evaluation was performed using structural analysis methods. A demonstration combining simplified model tests and nonlinear finite element analyses was made to substantiate the structural analysis methods used to evaluate the Shippingport package. The package was analyzed and the results indicate that the package meets external radiation standards and release limits of 10 CFR 71. 13 refs., 50 figs., 19 tabs.

  9. Impact of childbirth and mode of delivery on vaginal resting pressure and on pelvic floor muscle strength and endurance.

    Science.gov (United States)

    Hilde, Gunvor; Stær-Jensen, Jette; Siafarikas, Franziska; Engh, Marie Ellström; Brækken, Ingeborg Hoff; Bø, Kari

    2013-01-01

    We sought to study impact of delivery mode on vaginal resting pressure (VRP) and on pelvic floor muscle (PFM) strength and endurance, and whether these measurements differed in women with and without urinary incontinence. We conducted a cohort study following 277 nulliparous women from midpregnancy to 6 weeks postpartum. Manometer was used for PFM measurements; differences were analyzed by t test (within groups) and analysis of variance (between groups). Only VRP changed significantly (10% reduction, P = .001) after emergency cesarean section. After normal and instrumental vaginal delivery, VRP was reduced by 29% and 30%; PFM strength by 54% and 66%; and endurance by 53% and 65%, respectively. Significant differences for all PFM measures (P VRP and in PFM strength and endurance were found after vaginal delivery. Continent women were stronger than incontinent counterparts. Copyright © 2013 Mosby, Inc. All rights reserved.

  10. Spectroscopic Confusion: Its Impact on Current and Future Extragalactic HI Surveys

    CERN Document Server

    Jones, Michael G; Haynes, Martha P; Giovanelli, Riccardo

    2015-01-01

    We present a comprehensive model to predict the rate of spectroscopic confusion in HI surveys, and demonstrate good agreement with the observable confusion in existing surveys. Generically the action of confusion on the HI mass function was found to be a suppression of the number count of sources below the `knee', and an enhancement above it. This results in a bias, whereby the `knee' mass is increased and the faint end slope is steepened. For ALFALFA and HIPASS we find that the maximum impact this bias can have on the Schechter fit parameters is similar in magnitude to the published random errors. On the other hand, the impact of confusion on the HI mass functions of upcoming medium depth interferometric surveys, will be below the level of the random errors. In addition, we find that previous estimates of the number of detections for upcoming surveys with SKA-precursor telescopes may have been too optimistic, as the framework implemented here results in number counts between 60% and 75% of those previously p...

  11. Mechanistic insights into the impact of Cold Atmospheric Pressure Plasma on human epithelial cell lines

    Science.gov (United States)

    Dezest, Marlène; Chavatte, Laurent; Bourdens, Marion; Quinton, Damien; Camus, Mylène; Garrigues, Luc; Descargues, Pascal; Arbault, Stéphane; Burlet-Schiltz, Odile; Casteilla, Louis; Clément, Franck; Planat, Valérie; Bulteau, Anne-Laure

    2017-01-01

    Compelling evidence suggests that Cold Atmospheric Pressure Plasma (CAPP) has potential as a new cancer therapy. However, knowledge about cellular signaling events and toxicity subsequent to plasma treatment is still poorly documented. The aim of this study was to focus on the interaction between 3 different types of plasma (He, He-O2, He-N2) and human epithelial cell lines to gain better insight into plasma-cell interaction. We provide evidence that reactive oxygen and nitrogen species (RONS) are inducing cell death by apoptosis and that the proteasome, a major intracellular proteolytic system which is important for tumor cell growth and survival, is a target of (He or He-N2) CAPP. However, RONS are not the only actors involved in cell death; electric field and charged particles could play a significant role especially for He-O2 CAPP. By differential label-free quantitative proteomic analysis we found that CAPP triggers antioxidant and cellular defense but is also affecting extracellular matrix in keratinocytes. Moreover, we found that malignant cells are more resistant to CAPP treatment than normal cells. Taken together, our findings provide insight into potential mechanisms of CAPP-induced proteasome inactivation and the cellular consequences of these events.

  12. Mechanistic insights into the impact of Cold Atmospheric Pressure Plasma on human epithelial cell lines

    Science.gov (United States)

    Dezest, Marlène; Chavatte, Laurent; Bourdens, Marion; Quinton, Damien; Camus, Mylène; Garrigues, Luc; Descargues, Pascal; Arbault, Stéphane; Burlet-Schiltz, Odile; Casteilla, Louis; Clément, Franck; Planat, Valérie; Bulteau, Anne-Laure

    2017-01-01

    Compelling evidence suggests that Cold Atmospheric Pressure Plasma (CAPP) has potential as a new cancer therapy. However, knowledge about cellular signaling events and toxicity subsequent to plasma treatment is still poorly documented. The aim of this study was to focus on the interaction between 3 different types of plasma (He, He-O2, He-N2) and human epithelial cell lines to gain better insight into plasma-cell interaction. We provide evidence that reactive oxygen and nitrogen species (RONS) are inducing cell death by apoptosis and that the proteasome, a major intracellular proteolytic system which is important for tumor cell growth and survival, is a target of (He or He-N2) CAPP. However, RONS are not the only actors involved in cell death; electric field and charged particles could play a significant role especially for He-O2 CAPP. By differential label-free quantitative proteomic analysis we found that CAPP triggers antioxidant and cellular defense but is also affecting extracellular matrix in keratinocytes. Moreover, we found that malignant cells are more resistant to CAPP treatment than normal cells. Taken together, our findings provide insight into potential mechanisms of CAPP-induced proteasome inactivation and the cellular consequences of these events. PMID:28120925

  13. Impact of olmesartan on blood pressure, endothelial function, and cardiovascular outcomes

    Directory of Open Access Journals (Sweden)

    Eduardo Pimenta

    2010-09-01

    Full Text Available Eduardo Pimenta1, Suzanne Oparil21Endocrine Hypertension Research Centre and Clinical Centre of Research Excellence in Cardiovascular Disease and Metabolic Disorders, University of Queensland School of Medicine, Princess Alexandra Hospital, Brisbane, Queensland, Australia; 2Vascular Biology and Hypertension Program, University of Alabama at Birmingham, Birmingham, AL, USAAbstract: The vascular endothelium, the largest “organ” in the body, synthesizes and releases a wide spectrum of vasoactive substances into the circulation. Endothelial dysfunction links hypertension and other cardiovascular (CV risk factors that promote the development of atherosclerotic plaque, CV disease, and fatal and nonfatal CV events. Blood pressure (BP reduction is the most effective way to reduce CV risk in patients with hypertension, but it is unknown whether endothelial dysfunction is a cause or consequence of hypertension. Renin–angiotensin–aldosterone system blockers improve endothelial function and have favorable vascular, metabolic, cardiac, and renoprotective effects that are independent of BP reduction. Olmesartan effectively reduces BP and also has vasoprotective properties, including reductions in endothelial dysfunction and inflammation, prevention of microalbuminuria, and reversal of vascular remodeling. Large-scale, long-term studies are needed to confirm that olmesartan has vasoprotective effects that are independent of BP control and to determine whether these pleiotropic effects translate into improved CV disease outcomes.Keywords: hypertension, endothelial function, cardiovascular outcomes, olmesartan

  14. The impact of coffee consumption on blood pressure, cardiovascular disease and diabetes mellitus.

    Science.gov (United States)

    Chrysant, Steven G

    2017-03-01

    Coffee is the most widely consumed beverage, next to water. However, there has been a long-standing controversy regarding its safety on blood pressure (BP) and cardiovascular disease (CVD) and intuitively, physicians dissuaded their patients from coffee drinking. Areas covered: This controversy was, primarily, based on older prospective studies or case reports, which showed a positive association of coffee drinking with the incidence of hypertension and CVD. In contrast to these reports, recent, well controlled, studies have demonstrated either a neutral or beneficial effect of moderate coffee consumption (3-4 cups/day), on BP, CVD, heart failure (HF), cardiac arrhythmias, or diabetes mellitus (DM). For the preparation of this special report, an English language focused search of the Medline database was conducted between 2010 and 2016 on studies with data on effect on the coffee consumption in patients with high BP, CVD, HF, cardiac arrhythmias or DM. Of the 94 abstracts reviewed, 34 pertinent papers were selected, and the findings from these papers together with collateral literature will be discussed in this special report. Expert commentary: Based on the evidence from these studies, coffee consumption in moderation, is safe and is beneficial in both healthy persons as well as patients with high BP, CVD, HF, cardiac arrhythmias or DM. Therefore, coffee restriction is not warranted for these patients, although some caution should be exercised.

  15. Impact of effluent organic matter on low-pressure membrane fouling in tertiary treatment

    KAUST Repository

    Ayache, C.

    2013-05-01

    This study aims at comparing low-pressure membrane fouling obtained with two different secondary effluents at bench and pilot-scale based on the determination of two fouling indices: the total fouling index (TFI) and the hydraulically irreversible fouling index (HIFI). The main objective was to investigate if simpler and less costly bench-scale experimentation can substitute for pilot-scale trials when assessing the fouling potential of secondary effluent in large scale membrane filtration plants producing recycled water. Absolute values for specific flux and total fouling index for the bench-scale system were higher than those determined from pilot-scale, nevertheless a statistically significant correlation (r2 = 0.63, α = 0.1) was obtained for the total fouling index at both scales. On the contrary no such correlation was found for the hydraulically irreversible fouling index. Advanced water characterization tools such as excitation-emission matrix fluorescence spectroscopy (EEM) and liquid chromatography with organic carbon detection (LC-OCD) were used for the characterization of foulants. On the basis of statistical analysis, biopolymers and humic substances were found to be the major contribution to total fouling (r2 = 0.95 and r2 = 0.88, respectively). Adsorption of the low molecular weight neutral compounds to the membrane was attributed to hydraulically irreversible fouling (r2 = 0.67). © 2013 Elsevier Ltd.

  16. Foreign Entry Modes Under Institutional Pressures: The Impact of Strategic Resource Seeking and Market Seeking Strategies

    Directory of Open Access Journals (Sweden)

    Manuel Portugal Ferreira

    2008-01-01

    Full Text Available http://dx.doi.org/10.5007/2175-8069.2008v10n22p11Multinational corporations (MNCs are subject to the various dimensions of the external institutional environments. Institutional theory suggests that MNCs need to conform to the prevailing rules, norms and procedures of the locations where they operate in order to survive and grow. This means that MNCs need to develop the best possible configuration of strategy-structure for their worldwide operations. Previous research has noted that in these conditions firms may simply seek to follow a referent other. However, MNCs’ specific strategy for a focal foreign operation is likely to determine the entry mode for each host country. In certain circumstances it may be whether MNCs are pursuing a market-seeking strategy or a strategic resource seeking strategy that shapes the entry mode in face of the prevailing institutional pressures. We contribute to the understanding of entry modes into foreign markets as a reflection of a strategic choice that is bound by institutional constraints.

  17. Upper extremity sarcoma: impact of current practice guidelines and controversies on reconstructive approaches

    Directory of Open Access Journals (Sweden)

    Dobke Marek

    2017-01-01

    Full Text Available The goals of sarcoma management include both a cure and the functional preservation of involved tissues and adjacent critical structures with common opinions favoring immediate reconstruction. The question arises whether these goals are contradictory. This paper discusses the question based on the experience of 28 patients with different types of extremity sarcoma, with 24 surgically treated by the University of California San Diego (UCSD orthopedic and plastic surgery team (2011–2016 and the collection of evidence from published practice guidelines, reviews, case studies, and clinical trials. Included are the impact of limb-sparing and functional reconstructive concepts, efforts regarding the adequacy of surgical margins, and the rationale of immediate versus delayed reconstructive approaches, and the disease-free status of sarcoma management.

  18. Current technological advances in magnetic resonance with critical impact for clinical diagnosis and therapy.

    Science.gov (United States)

    Runge, Val M

    2013-12-01

    The last 5 years of technological advances with major impact on clinical magnetic resonance (MR) are discussed, with greater emphasis on those that are most recent. These developments have already had a critical positive effect on clinical diagnosis and therapy and presage continued rapid improvements for the next 5 years. This review begins with a discussion of 2 topics that encompass the breadth of MR, in terms of anatomic applications, contrast media, and MR angiography. Subsequently, innovations are discussed by anatomic category, picking the areas with the greatest development, starting with the brain, moving forward to the liver and kidney, and concluding with the musculoskeletal system, breast, and prostate. Two final topics are then considered, which will likely, with time, become independent major fields in their own right, interventional MR and MR positron emission tomography (PET).The next decade will bring a new generation of MR contrast media, with research focused on substantial improvements (>100-fold) in relaxivity (contrast effect), thus providing greater efficacy, safety, and tissue targeting. Magnetic resonance angiography will see major advances because of the use of compressed sensing, in terms of spatial and temporal resolution, with movement away from nondynamic imaging. The breadth of available techniques and tissue contrast has greatly expanded in brain imaging, benefiting both from the introduction of new basic categories of imaging techniques, such as readout-segmented echo planar imaging and 3D fast spin echo imaging with variable flip angles, and from new refinements specific to anatomic areas, such as double inversion recovery and MP2RAGE. Liver imaging has benefited from the development of techniques to easily and rapidly assess lipid, and will see, overall, a marked improvement in the next 5 years from new techniques on the verge of clinical introduction, such as controlled aliasing in parallel imaging results in higher acceleration

  19. THE IMPACT OF THE ACTIONS OF EDUCATION INSPECTION IN THE CURRENT TEACHER TRAINING

    Directory of Open Access Journals (Sweden)

    Miguel Ángel González Ortiz

    2016-06-01

    Full Text Available This article analyses the impact that a priority action on the assessment process in vocational training has had. It has been carried out by the General Education Inspection of Castilla-La Mancha throughout this school year and it is classified within the overall action and training plan for the teachers who teach this level through the Regional Centre for Teacher Training. For the analysis of this work, we took into account the degree of involvement of the teachers who teach middle and upper-grade vocational training who were enrolled in a specific course organised by the Regional Centre for Teacher Training called Didactic syllabi and assessment processes in Vocational Training. These teachers belonged to schools that offer middle and upper-grade vocational training which were supervised by education inspectors of Castilla-La Mancha.The conclusions obtained in the analysis of this work are a true reflection of the performance of education inspection in vocational training.

  20. Early Childhood Caries and the Impact of Current U.S. Medicaid Program: An Overview

    Directory of Open Access Journals (Sweden)

    Bussma Ahmed Bugis

    2012-01-01

    Full Text Available Pediatric dental caries is the most common chronic disease among children. Above 40% of the U.S. children aged 2–11 years have dental caries; more than 50% of them come from low-income families. Under dental services of the Medicaid program, children enrolled in Medicaid must receive preventive dental services. However, only 1/5 of them utilize preventive dental services. The purpose of this overview is to measure the impact of Medicaid dental benefits on reducing oral health disparities among Medicaid-eligible children. This paper explains the importance of preventive dental care, children at high risk of dental caries, Medicaid dental benefits, utilization of dental preventive services by Medicaid-eligible children, dental utilization influencing factors, and outcome evaluation of Medicaid in preventing dental caries among children. In conclusion, despite the recent increase of children enrolled in Medicaid, utilizing preventive dental care is still a real challenge that faces Medicaid.

  1. THE IMPACT OF PROMOTION CAMPAIGNS OVER THE COMPANIES IN THE CURRENT ECONOMIC CONTEXT

    Directory of Open Access Journals (Sweden)

    FRÂNCU LAURENȚIU GABRIEL

    2015-12-01

    Full Text Available In an increasingly competitive business environment, promotion campaigns have a great significance in terms of market positioning of companies. The promotion campaigns are having a key role, sometimes even vital, because the companies depend on their results. An remarkable promotion campaign will lead to an increase in company sales and a better market positioning. The brand awareness will increase and the customers will become more loyal and may even be attracted new customers. This paper aims to analyze the impact of promotion campaigns over the courier companies from Romania. Thus, will be analysed the courier companies market and the competitive advantage in this market when it is used an efficient strategy of promotion campaigns.

  2. Wave-current interactions in the southern North Sea: The impact on salinity

    Science.gov (United States)

    Schloen, Julia; Stanev, Emil V.; Grashorn, Sebastian

    2017-03-01

    The interplay between wind waves and currents in the coastal zone of the southern North Sea along with the resulting changes in the salinity distribution are quantified using simulations with the unstructured-grid ocean model SCHISM coupled with the wind wave model WWM III. Several sensitivity runs, which are carried out to estimate the individual contributions of different physical mechanisms and forcing, demonstrated that the density gradients in the coastal zone reduce tidal current by 18%, whereas the wind waves enhance the circulation in some cases. The latter happens when along-shore wind speed approaches ∼10 m s-1 resulting in long-shore currents following the western Dutch coast and the German Wadden Sea islands. The wave-induced transport of salt leads to changes in the horizontal salinity distribution. These are most pronounced in front of barrier islands where coherent patterns caused by the coupling between tides, surface drift, and wind waves reveal salinity changes up to 0.5. The weak stratification of salinity in the coastal zone is mostly destroyed by wind waves. Thus, effects created by wind waves tend to substantially modify the estuarine circulation. An explanation of these important processes in the coastal zone has been given based on an analysis of the ratio between significant wave height and tidal range. This control-parameter, which is relatively small under mild weather conditions, can exceed unity under strong wind conditions in the coastal zone, thus mixing due to waves becomes dominant. The effect of fresh water fluxes from subterranean estuaries is relatively small and confined only in the vicinity of corresponding sources.

  3. Lowering district heating temperatures – Impact to system performance in current and future Danish energy scenarios

    DEFF Research Database (Denmark)

    Ommen, Torben; Markussen, Wiebke Brix; Elmegaard, Brian

    2016-01-01

    CHP (Combined heat and power) production in connection with DH (district heating) systems has previously demonstrated a significant reduction in primary energy consumption. With extended installation of intermittent sustainable sources, such as eg. wind turbines rather than thermal units....... Utility plants and demand curves corresponded to the current and future scenarios for the DH system of Greater Copenhagen. Performance curves from typical CHP-plant technologies were used to represent the changed operation of power and heat production for changed DH temperatures. The results show...

  4. Physiological impact of CTO recanalization assessed by coronary pressure measurement: a case report.

    Science.gov (United States)

    Matsuo, Hitoshi; Kawase, Yoshiaki

    2013-10-01

    In this case report, physiological changes of myocardial perfusion in the collateral recipient right coronary artery (RCA) and the collateral donor left anterior descending artery (LAD) with an intermediate lesion were assessed using intracoronary pressure measurement, before and after revascularization of chronic total occlusion (CTO). A 44-year-old male was referred for a catheter examination due to silent myocardial ischemia. An invasive coronary angiogram revealed diffuse narrowing of the RCA with focal occlusive segments in addition to intermediate stenosis in the LAD. A well developed collateral channel from the LAD to the RCA was also confirmed. Fractional flow reserve (FFRmyo) of the LAD before opening the RCA was 0.81. After successful revascularization of the RCA, FFRmyo of the LAD and the RCA were measured with and without an RCA balloon occlusion. Because collateral fractional flow reserve (FFRcoll) of the RCA could be regarded as FFRmyo before revascularization, FFRmyo of the RCA increased from 0.67 to 0.90, meaning a 23% increase of maximum flow by intervention. Interestingly, improvement of FFRmyo of the LAD from 0.81 to 0.93 was also observed, which means a 12% increase of maximum flow. Coronary steal in the LAD was reconfirmed by dramatic worsening of FFRmyo from 0.93 to 0.77 by an RCA balloon occlusion. This phenomenon may be explained by an immediate recruitment of collateral channels. This case clearly demonstrated that CTO opening improves perfusion in not only myocardium supplied by the CTO vessel, but also in that which is supplied by a contralateral collateral donor artery. Copyright © 2013 Wiley Periodicals, Inc.

  5. Impact of sodium–glucose cotransporter 2 inhibitors on blood pressure

    Science.gov (United States)

    Reed, James W

    2016-01-01

    SGLT2 inhibitors are glucose-lowering agents used to treat type 2 diabetes mellitus (T2DM). These agents target the kidney to promote urinary glucose excretion, resulting in improved blood glucose control. SGLT2-inhibitor therapy is also associated with weight loss and blood pressure (BP) lowering. Hypertension is a common comorbidity in patients with T2DM, and is associated with excess morbidity and mortality. This review summarizes data on the effect of SGLT2 inhibitors marketed in the US (namely canagliflozin, dapagliflozin, or empagliflozin) on BP in patients with T2DM. Boolean searches were conducted that included terms related to BP or hypertension with terms for SGLT2 inhibitors, canagliflozin, dapagliflozin, or empagliflozin using PubMed, Google, and Google Scholar. Data from numerous randomized controlled trials of SGLT2 inhibitors in patients with T2DM demonstrated clinically relevant reductions in both systolic and diastolic BP, assessed via seated office measurements and 24-hour ambulatory BP monitoring. Observed BP lowering was not associated with compensatory increases in heart rate. Circadian BP rhythm was also maintained. The mechanism of SGLT2 inhibitor-associated BP reduction is not fully understood, but is assumed to be related to osmotic diuresis and natriuresis. Other factors that may also contribute to BP reduction include SGLT2 inhibitor-associated decreases in body weight and reduced arterial stiffness. Local inhibition of the renin–angiotensin–aldosterone system secondary to increased delivery of sodium to the juxtaglomerular apparatus during SGLT2 inhibition has also been postulated. Although SGLT2 inhibitors are not indicated as BP-lowering agents, the modest decreases in systolic and diastolic BP observed with SGLT2 inhibitors may provide an extra clinical advantage for the majority of patients with T2DM, in addition to improving blood glucose control. PMID:27822054

  6. Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain

    Directory of Open Access Journals (Sweden)

    Aminath eAzhan

    2012-12-01

    Full Text Available Systemic hypotension in preterm infants has been related to increased mortality, cerebrovascular lesions and neurodevelopmental morbidity. Treatment of hypotension with inotropic medications aims at preservation of end organ perfusion and oxygen delivery, especially the brain. The common inotropic medications in preterm infants include dopamine, dobutamine, adrenalin, with adjunctive use of corticosteroids in cases of refractory hypotension. Whether maintenance of mean arterial blood pressure (MAP by use of inotropic medication is neuroprotective or not remains unclear. This review explores the different inotropic agents and their effects on perfusion and oxygenation in the preterm brain, in clinical studies as well as in animal models. Dopamine and adrenalin, because of their -adrenergic vasoconstrictor actions, have raised concerns of reduction in cerebral blood flow (CBF. Several studies in hypotensive preterm infants have shown that dopamine elevates CBF together with increased MAP, in keeping with limited cerebro-autoregulation. Adrenaline is also effective in raising cerebral perfusion together with MAP in preterm infants. Experimental studies in immature animals show no cerebro-vasoconstrictive effects of dopamine or adrenaline, but demonstrate the consistent findings of increased cerebral perfusion and oxygenation with the use of dopamine, dobutamine and adrenaline, alongside with raised MAP. Both clinical and animal studies report the transitory effects of adrenaline in increasing plasma lactate, and blood glucose, which might render its use as a 2nd line therapy. To investigate the cerebral effects of inotropic agents in long-term outcome in hypotensive preterm infants, carefully designed prospective research possibly including preterm infants with permissive hypotension is required. Preterm animal models would be useful in investigating the relationship between the physiological effects of inotropes and histopathology outcomes in

  7. The Impacts of Maximum Temperature and Climate Change to Current and Future Pollen Distribution in Skopje, Republic of Macedonia

    Directory of Open Access Journals (Sweden)

    Vladimir Kendrovski

    2012-02-01

    Full Text Available BACKGROUND. The goal of the present paper was to assess the impact of current and future burden of the ambient temperature to pollen distributions in Skopje. METHODS. In the study we have evaluated a correlation between the concentration of pollen grains in the atmosphere of Skopje and maximum temperature, during the vegetation period of 1996, 2003, 2007 and 2009 as a current burden in context of climate change. For our analysis we have selected 9 representative of each phytoallergen group (trees, grasses, weeds. The concentration of pollen grains has been monitored by a Lanzoni volumetric pollen trap. The correlation between the concentration of pollen grains in the atmosphere and selected meteorological variable from weekly monitoring has been studied with the help of linear regression and correlation coefficients. RESULTS. The prevalence of the sensibilization of standard pollen allergens in Skopje during the some period shows increasing from 16,9% in 1996 to 19,8% in 2009. We detect differences in onset of flowering, maximum and end of the length of seasons for pollen. The pollen distributions and risk increases in 3 main periods: early spring, spring and summer which are the main cause of allergies during these seasons. The largest increase of air temperature due to climate change in Skopje is expected in the summer season. CONCLUSION. The impacts of climate change by increasing of the temperature in the next decades very likely will include impacts on pollen production and differences in current pollen season. [TAF Prev Med Bull 2012; 11(1.000: 35-40

  8. The impact of antiretroviral therapy in resource-limited settings and current HIV therapeutics.

    Science.gov (United States)

    Kumarasamy, N

    2016-04-01

    Four million people of the global total of 35 million with HIV infection are from South-East Asia. ART is currently utilized by 15 million people and has led to a dramatic decline in the mortality rate, including those in low- and middle-income countries. A reduction in sexually transmitted HIV and in comorbidities including tuberculosis has also followed. Current recommendations for the initiation of antiretroviral therapy in people who are HIV+ are essentially to initiate ART irrespective of CD4 cell count and clinical stage. The frequency of HIV testing should be culturally specific and based on the HIV incidence in different key populations but phasing in viral load technology in LMIC is an urgent priority and this needs resources and capacity. With the availability of simplified potent ART regimens, persons with HIV now live longer. The recent WHO treatment guidelines recommending routine HIV testing and earlier initiation of treatment should be the stepping stone for ending the AIDS epidemic and to meet the UNAIDS mission of 90*90*90.

  9. GRAPEVINE VIRUS DISEASES:ECONOMIC IMPACT AND CURRENT ADVANCES IN VIRAL PROSPECTION AND MANAGEMENT

    Directory of Open Access Journals (Sweden)

    MARCOS FERNANDO BASSO

    Full Text Available ABSTRACT Grapevine (Vitis spp. is a major vegetative propagated fruit crop with high socioeconomic importance worldwide. It is susceptible to several graft-transmitted agents that cause several diseases and substantial crop losses, reducing fruit quality and plant vigor, and shorten the longevity of vines. The vegetative propagation and frequent exchanges of propagative material among countries contribute to spread these pathogens, favoring the emergence of complex diseases. Its perennial life cycle further accelerates the mixing and introduction of several viral agents into a single plant. Currently, approximately 65 viruses belonging to different families have been reported infecting grapevines, but not all cause economically relevant diseases. The grapevine leafroll, rugose wood complex, leaf degeneration and fleck diseases are the four main disorders having worldwide economic importance. In addition, new viral species and strains have been identified and associated with economically important constraints to grape production. In Brazilian vineyards, eighteen viruses, three viroids and two virus-like diseases had already their occurrence reported and were molecularly characterized. Here, we review the current knowledge of these viruses, report advances in their diagnosis and prospection of new species, and give indications about the management of the associated grapevine diseases.

  10. The impact of shearing flows on electroactive biofilm formation, structure, and current generation

    Science.gov (United States)

    Jones, A.-Andrew; Buie, Cullen

    2016-11-01

    A special class of bacteria exist that directly produce electricity. First explored in 1911, these electroactive bacteria catalyze hydrocarbons and transport electrons directly to a metallic electron acceptor forming thicker biofilms than other species. Electroactive bacteria biofilms are thicker because they are not limited by transport of oxygen or other terminal electron acceptors. Electroactive bacteria can produce power in fuel cells. Power production is limited in fuel cells by the bacteria's inability to eliminate protons near the insoluble electron acceptor not utilized in the wild. To date, they have not been successfully evolved or engineered to overcome this limit. This limitation may be overcome by enhancing convective mass transport while maintaining substantial biomass within the biofilm. Increasing convective mass transport increases shear stress. A biofilm may respond to increased shear by changing biomass, matrix, or current production. In this study, a rotating disk electrode is used to separate nutrient from physical stress. This phenomenon is investigated using the model electroactive bacterium Geobacter sulfurreducens at nutrient loads comparable to flow-through microbial fuel cells. We determine biofilm structure experimentally by measuring the porosity and calculating the tortuosity from confocal microscope images. Biofilm adaptation for electron transport is quantified using electrical impedance spectroscopy. Our ultimate objective is a framework relating biofilm thickness, porosity, shear stress and current generation for the optimization of bioelectrochemical systems The Alfred P Sloan Foundation MPHD Program.

  11. A Strategy of Suppressing the Underground Impact Scattered Current in Power Grid by Using Insulation Baffle

    Science.gov (United States)

    Zhan, Qinghua; Chen, Zhucheng; Li, Hongtao; Liu, Yijun; Mei, Cheng; He, Zhijie

    2017-05-01

    In order to solve the accidents happened in the ponds or other special places around the tower which were caused by the diffusion current after lightning stroke the transmission tower, the protection measures for the problem tower in the area of Guangdong Province which occurred dead fish in the pond in thunderstorm weather were studied in this paper. The COMSOL mutiphysics simulation software was used in order to calculate the electromagnetic environment of the diffusion situation by grounding device after lightning stroke the power transmission tower. Study concluded that the safe distance between the fish pond and grounding device of transmission tower is 14 meter. The effects of the length and depth or stayed a gap of the insulation baffle on the fish in the fish pond were discussed. The protection method of the insulation baffle has important practical significance to the protection of the grounding device for diffusion current, and can provide some engineering guidance and basis for the grounding arrangement and transformation of the high voltage transmission line tower.

  12. Effective population size dynamics reveal impacts of historic climatic events and recent anthropogenic pressure in African elephants.

    Science.gov (United States)

    Okello, J B A; Wittemyer, G; Rasmussen, H B; Arctander, P; Nyakaana, S; Douglas-Hamilton, I; Siegismund, H R

    2008-09-01

    Two hundred years of elephant hunting for ivory, peaking in 1970-1980s, caused local extirpations and massive population declines across Africa. The resulting genetic impacts on surviving populations have not been studied, despite the importance of understanding the evolutionary repercussions of such human-mediated events on this keystone species. Using Bayesian coalescent-based genetic methods to evaluate time-specific changes in effective population size, we analysed genetic variation in 20 highly polymorphic microsatellite loci from 400 elephants inhabiting the greater Samburu-Laikipia region of northern Kenya. This area experienced a decline of between 80% and 90% in the last few decades when ivory harvesting was rampant. The most significant change in effective population size, however, occurred approximately 2500 years ago during a mid-Holocene period of climatic drying in tropical Africa. Contrary to expectations, detailed analyses of four contemporary age-based cohorts showed that the peak poaching epidemic in the 1970s caused detectable temporary genetic impacts, with genetic diversity rebounding as juveniles surviving the poaching era became reproductively mature. This study demonstrates the importance of climatic history in shaping the distribution and genetic history of a keystone species and highlights the utility of coalescent-based demographic approaches in unravelling ancestral demographic events despite a lack of ancient samples. Unique insights into the genetic signature of mid-Holocene climatic change in Africa and effects of recent poaching pressure on elephants are discussed.

  13. The Impact of Different Absolute Solar Irradiance Values on Current Climate Model Simulations

    Science.gov (United States)

    Rind, David H.; Lean, Judith L.; Jonas, Jeffrey

    2014-01-01

    Simulations of the preindustrial and doubled CO2 climates are made with the GISS Global Climate Middle Atmosphere Model 3 using two different estimates of the absolute solar irradiance value: a higher value measured by solar radiometers in the 1990s and a lower value measured recently by the Solar Radiation and Climate Experiment. Each of the model simulations is adjusted to achieve global energy balance; without this adjustment the difference in irradiance produces a global temperature change of 0.48C, comparable to the cooling estimated for the Maunder Minimum. The results indicate that by altering cloud cover the model properly compensates for the different absolute solar irradiance values on a global level when simulating both preindustrial and doubled CO2 climates. On a regional level, the preindustrial climate simulations and the patterns of change with doubled CO2 concentrations are again remarkably similar, but there are some differences. Using a higher absolute solar irradiance value and the requisite cloud cover affects the model's depictions of high-latitude surface air temperature, sea level pressure, and stratospheric ozone, as well as tropical precipitation. In the climate change experiments it leads to an underestimation of North Atlantic warming, reduced precipitation in the tropical western Pacific, and smaller total ozone growth at high northern latitudes. Although significant, these differences are typically modest compared with the magnitude of the regional changes expected for doubled greenhouse gas concentrations. Nevertheless, the model simulations demonstrate that achieving the highest possible fidelity when simulating regional climate change requires that climate models use as input the most accurate (lower) solar irradiance value.

  14. Assessing and analysing the impact of land take pressures on arable land

    Science.gov (United States)

    Aksoy, Ece; Gregor, Mirko; Schröder, Christoph; Löhnertz, Manuel; Louwagie, Geertrui

    2017-06-01

    Land, and in particular soil, is a finite and essentially non-renewable resource. Across the European Union, land take, i.e. the increase of settlement area over time, annually consumes more than 1000 km2 of which half is actually sealed and hence lost under impermeable surfaces. Land take, and in particular soil sealing, has already been identified as one of the major soil threats in the 2006 European Commission Communication Towards a Thematic Strategy on Soil Protection and the Soil Thematic Strategy and has been confirmed as such in the report on the implementation of this strategy. The aim of this study is to relate the potential of land for a particular use in a given region with the actual land use. This allows evaluating whether land (especially the soil dimension) is used according to its (theoretical) potential. To this aim, the impact of several land cover flows related to urban development on soils with good, average, and poor production potentials were assessed and mapped. Thus, the amount and quality (potential for agricultural production) of arable land lost between the years 2000 and 2006 was identified. In addition, areas with high productivity potential around urban areas, indicating areas of potential future land use conflicts for Europe, were identified.

  15. Assessing the Impact of Earth Radiation Pressure Acceleration on Low-Earth Orbit Satellites

    Science.gov (United States)

    Vielberg, Kristin; Forootan, Ehsan; Lück, Christina; Kusche, Jürgen; Börger, Klaus

    2017-04-01

    The orbits of satellites are influenced by several external forces. The main non-gravitational forces besides thermospheric drag, acting on the surface of satellites, are accelerations due to the Earth and Solar Radiation Pres- sure (SRP and ERP, respectively). The sun radiates visible and infrared light reaching the satellite directly, which causes the SRP. Earth also emits and reflects the sunlight back into space, where it acts on satellites. This is known as ERP acceleration. The influence of ERP increases with decreasing distance to the Earth, and for low-earth orbit (LEO) satellites ERP must be taken into account in orbit and gravity computations. Estimating acceler- ations requires knowledge about energy emitted from the Earth, which can be derived from satellite remote sensing data, and also by considering the shape and surface material of a satellite. In this sensitivity study, we assess ERP accelerations based on different input albedo and emission fields and their modelling for the satellite missions Challenging Mini-Satellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE). As input fields, monthly 1°x1° products of Clouds and the Earth's Radiant En- ergy System (CERES), L3 are considered. Albedo and emission models are generated as latitude-dependent, as well as in terms of spherical harmonics. The impact of different albedo and emission models as well as the macro model and the altitude of satellites on ERP accelerations will be discussed.

  16. The impact of abnormal muscle tone from hemiplegia on reclining wheelchair positioning: a sliding and pressure evaluation.

    Science.gov (United States)

    Huang, H C; Lin, Y S; Chen, J M; Yeh, C H; Chung, K C

    2013-10-01

    Little is known about the influence of existing muscle tone abnormality on the sitting posture of stroke patients in reclining wheelchairs. To investigate the impact of muscle tone abnormality from hemiplegia on the forward sliding and pressure of stroke patients while sitting in reclining wheelchairs. Experimental study. The Assistive Devices/Technology Center at the Rehabilitation Department of hospital. 14 able-bodied elders and nonambulatory elderly stroke patients with flaccid (N.=12) or spastic hemiplegia (N.=13) participated in this study. Of the 12 patients with flaccid hemiplegia, 8 suffered from left-sided hemiplegia and 4 from right-sided hemiplegia. Of the 13 patients with spastic hemiplegia, 6 suffered from left-sided hemiplegia and 7 from right-sided hemiplegia. We performed 3 reclining cycles in wheelchairs with conventional seats and V-shaped seats for each participant. The sliding along the backrest (BS) plane and the seat (SS) plane, mean sitting pressure (MP), and sacral peak pressure (SPP) of the participants were recorded. The Kruskal-Wallis test was used to compare the difference in BS, SS, MP, and SPP between able-bodied elders and stroke patients. The BS, SS, and SPP during repetitive reclining were generally greatest in flaccid hemiplegic participants, followed by spastic hemiplegic participants, and finally by able-bodied participants. There was no significant difference in MP among three subject groups on both conventional seats and V-shaped seats in most comparisons. Able-bodied participants' buttocks tended to slide forward on conventional seats but backward on V-shaped seats, whereas hemiplegic participants' buttocks slid forward on both seat types. Stroke patients with flaccid hemiplegia are the most vulnerable to sacral sitting and higher sacral pressure in reclining wheelchairs, followed by patients with spastic hemiplegia. There is a difference in the displacement pattern between participants with normal muscle tone and those with

  17. Impact of cerebrospinal fluid shunting for idiopathic normal pressure hydrocephalus on the amyloid cascade.

    Directory of Open Access Journals (Sweden)

    Masao Moriya

    Full Text Available The aim of this study was to determine whether the improvement of cerebrospinal fluid (CSF flow dynamics by CSF shunting, can suppress the oligomerization of amyloid β-peptide (Aβ, by measuring the levels of Alzheimer's disease (AD-related proteins in the CSF before and after lumboperitoneal shunting. Lumbar CSF from 32 patients with idiopathic normal pressure hydrocephalus (iNPH (samples were obtained before and 1 year after shunting, 15 patients with AD, and 12 normal controls was analyzed for AD-related proteins and APLP1-derived Aβ-like peptides (APL1β (a surrogate marker for Aβ. We found that before shunting, individuals with iNPH had significantly lower levels of soluble amyloid precursor proteins (sAPP and Aβ38 compared to patients with AD and normal controls. We divided the patients with iNPH into patients with favorable (improvement ≥ 1 on the modified Rankin Scale and unfavorable (no improvement on the modified Rankin Scale outcomes. Compared to the unfavorable outcome group, the favorable outcome group showed significant increases in Aβ38, 40, 42, and phosphorylated-tau levels after shunting. In contrast, there were no significant changes in the levels of APL1β25, 27, and 28 after shunting. After shunting, we observed positive correlations between sAPPα and sAPPβ, Aβ38 and 42, and APL1β25 and 28, with shifts from sAPPβ to sAPPα, from APL1β28 to 25, and from Aβ42 to 38 in all patients with iNPH. Our results suggest that Aβ production remained unchanged by the shunt procedure because the levels of sAPP and APL1β were unchanged. Moreover, the shift of Aβ from oligomer to monomer due to the shift of Aβ42 (easy to aggregate to Aβ38 (difficult to aggregate, and the improvement of interstitial-fluid flow, could lead to increased Aβ levels in the CSF. Our findings suggest that the shunting procedure can delay intracerebral deposition of Aβ in patients with iNPH.

  18. The impact of intraocular pressure on elastic wave velocity estimates in the crystalline lens

    Science.gov (United States)

    Park, Suhyun; Yoon, Heechul; Larin, Kirill V.; Emelianov, Stanislav Y.; Aglyamov, Salavat R.

    2017-02-01

    Intraocular pressure (IOP) is believed to influence the mechanical properties of ocular tissues including cornea and sclera. The elastic properties of the crystalline lens have been mainly investigated with regard to presbyopia, the age-related loss of accommodation power of the eye. However, the relationship between the elastic properties of the lens and IOP remains to be established. The objective of this study is to measure the elastic wave velocity, which represents the mechanical properties of tissue, in the crystalline lens ex vivo in response to changes in IOP. The elastic wave velocities in the cornea and lens from seven enucleated bovine globe samples were estimated using ultrasound shear wave elasticity imaging. To generate and then image the elastic wave propagation, an ultrasound imaging system was used to transmit a 600 µs pushing pulse at 4.5 MHz center frequency and to acquire ultrasound tracking frames at 6 kHz frame rate. The pushing beams were separately applied to the cornea and lens. IOP in the eyeballs was varied from 5 to 50 mmHg. The results indicate that while the elastic wave velocity in the cornea increased from 0.96  ±  0.30 m s-1 to 6.27  ±  0.75 m s-1 as IOP was elevated from 5 to 50 mmHg, there were insignificant changes in the elastic wave velocity in the crystalline lens with the minimum and the maximum speeds of 1.44  ±  0.27 m s-1 and 2.03  ±  0.46 m s-1, respectively. This study shows that ultrasound shear wave elasticity imaging can be used to assess the biomechanical properties of the crystalline lens noninvasively. Also, it was observed that the dependency of the crystalline lens stiffness on the IOP was significantly lower in comparison with that of cornea.

  19. The impact of the AEC mode of tube current on the dose at CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Il Bong; Dong, Kyung Rae [Dept. of Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of); Kim, Kwang Cheol [Dept. of of Nuclear Engineering, Chosun University,Gwangju (Korea, Republic of)

    2016-11-15

    In this study, the automatic exposure control (AEC) modes of tube current (SIEMENSCare Dose 4D and GE AEC mode) that CT manufacturers are using was applied to neck, chest and abdomen in order to determine the difference in the respective dose parameters (CTDIvol, DLP and mSv) resulting from the dose reduction. Equipment in use at C university adopted Care Dose 4D of Siemens and AEC mode of General Electric (GE), and the x-ray exposure conditions were adjusted to be as identical as possible between the experiments. For the assessment of the dose reduction, the differences between the doses with and without the use of the tube current AEC mode by the respective manufacturer were measured for each body part including neck, chest and abdomen of a human phantom, Rando Phantom (Art-200x, Fluke Biomedical, USA). First, the assessment of SIEMENS-Care Dose 4D yielded the following results. At the neck, the automatic exposure control resulted in a 3.3% reduction in CTDIvol and DLP, and a 3% reduction in the effective dose, mSv, compared to manual exposure control. The automatic exposure control at the chest displayed the reduction in CTDIvol and DLP by 25.5%, and in the effective dose, mSv, by 25.4% compared to the manual exposure control. In case of abdomen, CTDIvol and DLP were shown to be reduced by 16%, and the effective dose (mSv) by 16.3% under the automatic exposure control compared to the manual exposure. Second, the assessment results of GE AEC mode are as follows. The automatic exposure control at the neck resulted in a 45.1% reduction in CTDIvol and DLP, and a 44.7% reduction in the effective dose (mSv) in comparison to the manual exposure control. At the chest, the automatic exposure control displayed a 47.6% reduction in CTDIvol and DLP, and a 47.5% reduction in the effective dose, mSv, compared to the manual exposure control. At the abdomen, it was shown that CTDIvol and DLP were reduced by 26.9%, and the effective dose (mSv) by 26.8% under the automatic

  20. Assessment of the impact of HTSCs on superconducting fault-current limiters. [High Temperature SuperConductors (HTSCs)

    Energy Technology Data Exchange (ETDEWEB)

    Giese, R.F. (Argonne National Lab., IL (United States)); Runde, M. (Energiforsyningens Forskningsinstitutt A/S, Trondheim (Norway))

    1993-01-01

    The possible impact of nitrogen-cooled superconductors on the desip and cost of superconducting fault-current limiters is assessed by considering the technical specifications such devices must meet and by comparing material properties of 77-K and 4-K superconductors. The main advantages of operating superconductors at 77 K are that the refrigeration operating cost is reduced by a factor of up to 25 and the refrigeration capital cost is reduced by a factor of up to 10. The heat capacity is several orders of magnitude Larger at 77 K and at 4 K. This phenomenon increases conductor stability against flux jumps but makes switching from the superconducting to the normal state slow and difficult. Therefore, a high critical current density, probably at least 10[sup 5] A/cm[sup 2], is required.

  1. The Gulf Stream pathway and the impacts of the eddy-driven abyssal circulation and the Deep Western Boundary Current

    Science.gov (United States)

    Hurlburt, Harley E.; Hogan, Patrick J.

    2008-08-01

    A hydrodynamic model of the subtropical Atlantic basin and the Intra-Americas Sea (9-47°N) is used to investigate the dynamics of Gulf Stream separation from the western boundary at Cape Hatteras and its mean pathway to the Grand Banks. The model has five isopycnal Lagrangian layers in the vertical and allows realistic boundary geometry, bathymetry, wind forcing, and a meridional overturning circulation (MOC), the latter specified via ports in the northern and southern boundaries. The northward upper ocean branch of the MOC (14 Sv) was always included but the southward Deep Western Boundary Current (DWBC) was excluded in some simulations, allowing investigation of the impacts of the DWBC and the eddy-driven mean abyssal circulation on Gulf Stream separation from the western boundary. The result is resolution dependent with the DWBC playing a crucial role in Gulf Stream separation at 1/16° resolution but with the eddy-driven abyssal circulation alone sufficient to obtain accurate separation at 1/32° resolution and a realistic pathway from Cape Hatteras to the Grand Banks with minimal DWBC impact except southeast of the Grand Banks. The separation from the western boundary is particularly sensitive to the strength of the eddy-driven abyssal circulation. Farther to the east, between 68°W and the Grand Banks, all of the 1/16° and 1/32° simulations with realistic topography (with or without a DWBC) gave similar generally realistic mean pathways with clear impacts of the topographically constrained eddy-driven abyssal circulation versus very unrealistic Gulf Stream pathways between Cape Hatteras and the Grand Banks from otherwise identical simulations run with a flat bottom, in reduced-gravity mode, or with 1/8° resolution and realistic topography. The model is realistic enough to allow detailed model-data comparisons and a detailed investigation of Gulf Stream dynamics. The corresponding linear solution with a Sverdrup interior and Munk viscous western boundary

  2. Neutral-current neutrino-nucleus reactions and their impact to supernova physics

    Science.gov (United States)

    Tsakstara, V.; Kosmas, T. S.; Dzhioev, A. A.; Vdovin, A. I.

    2013-02-01

    We study neutral-current neutrino-nucleus reactions in nuclei that are relevant for supernova (SN) simulations and for terrestrial experiments aiming at neutrino astrophysics as well as ν-nucleus scattering cross sections measurements. Such studies allow us to improve estimates of nuclear responses to low energy neutrinos in light of the operation of nuclear v-detectors with very-low threshold and very high sensitivity. The adopted ν-energy range is extended to rather high energies (up to 100 MeV) so as to consider allowed and forbidden multipole contributions to cross sections. Both contributions are calculated within the quasi-particle random phase approximation by using realistic two-body forces (Bonn CD potential) for the residual interaction of the nuclear Hamiltonian. As a special application the 56Fe isotope is chosen due to its significant role in SN physics and ν-detection.

  3. Longitudinal impedance and wake from XFEL undulators. Impact on current-enhanced SASE schemes

    CERN Document Server

    Geloni, Gianluca; Schneidmiller, Evgeni; Yurkov, Mikhail

    2007-01-01

    In this article we derive longitudinal impedance and wake function for an undulator setup with arbitrary undulator parameter, taking into account a finite transverse size of the electron bunch. Earlier studies considered a line density-distribution of electrons instead. We focus our attention on the long-wavelength asymptote (compared with resonance wavelength), at large distance of the electron bunch from the undulator entrance compared to the overtaking length, and for large vacuum-chamber size compared to the typical transverse size of the field. These restrictions define a parameter region of interest for practical applications. We calculate a closed expression for impedance and wake function that may be evaluated numerically in the most general case. Such expression allows us to derive an analytical solution for a Gaussian transverse and longitudinal bunch shape. Finally, we study the feasibility of current-enhanced SASE schemes (ESASE) recently proposed for LCLS, that fall well-within our approximations...

  4. Evidence for impact induced pressure gradients on the Allende CV3 parent body: Consequences for fluid and volatile transport

    Science.gov (United States)

    Tait, Alastair W.; Fisher, Kent R.; Srinivasan, Poorna; Simon, Justin I.

    2016-11-01

    Carbonaceous chondrites, such as those associated with the Vigarano (CV) parent body, exhibit a diverse range of oxidative/reduced alteration mineralogy (McSween, 1977). Although fluids are often cited as the medium by which this occurs (Rubin, 2012), a mechanism to explain how this fluid migrates, and why some meteorite subtypes from the same planetary body are more oxidized than others remains elusive. In our study we examined a slab of the well-known Allende (CV3OxA) meteorite. Using several petrological techniques (e.g., Fry's and Flinn) and Computerized Tomography (CT) we discover it exhibits a strong penetrative planar fabric, resulting from strain partitioning among its major components: Calcium-Aluminum-rich Inclusions (CAIs) (64.5%CT) > matrix (21.5%Fry) > chondrules (17.6%CT). In addition to the planar fabric, we found a strong lineation defined by the alignment of the maximum elongation of flattened particles interpreted to have developed by an impact event. The existence of a lineation could either be non-coaxial deformation, or the result of a mechanically heterogeneous target material. In the later case it could have formed due to discontinuous patches of sub-surface ice and/or fabrics developed through prior impact compaction (MacPherson and Krot, 2014), which would have encouraged preferential flow within the target material immediately following the impact, compacting pore spaces. We suggest that structurally controlled movement of alteration fluids in the asteroid parent body along pressure gradients contributed to the formation of secondary minerals, which may have ultimately lead to the different oxidized subtypes.

  5. The impact of climate change on food security in South Africa: Current realities and challenges ahead

    Directory of Open Access Journals (Sweden)

    Tshepo S. Masipa

    2017-01-01

    Full Text Available This article aims to examine the impact of climate change on food security in South Africa. For this purpose, the article adopted a desktop study approach. Previous studies, reports, surveys and policies on climate change and food (insecurity. From this paper’s analysis, climate change presents a high risk to food security in sub-Saharan countries from crop production to food distribution and consumption. In light of this, it is found that climate change, particularly global warming, affects food security through food availability, accessibility, utilisation and affordability. To mitigate these risks, there is a need for an integrated policy approach to protect the arable land against global warming. The argument advanced in this article is that South Africa’s ability to adapt and protect its food items depends on the understanding of risks and the vulnerability of various food items to climate change. However, this poses a challenge in developing countries, including South Africa, because such countries have weak institutions and limited access to technology. Another concern is a wide gap between the cost of adapting and the necessary financial support from the government. There is also a need to invest in technologies that will resist risks on food systems.

  6. The Impact of Trampling on Reef Macrobenthos in Northeastern Brazil: How Effective are Current Conservation Strategies?

    Science.gov (United States)

    Santos, Gleice S.; Burgos, Douglas C.; Lira, Simone M. A.; Schwamborn, Ralf

    2015-10-01

    Tropical reefs are used for intensive tourism in various parts of the world. However, few studies have investigated the effect of regular trampling on these fragile ecosystems. The aim of this study was to assess the effect of different conservation strategies (open access, partial protection, and total long-term closure) on intertidal reef tops in Porto de Galinhas and Tamandaré, Pernambuco State, Brazil. Analysis of the macrobenthic community was performed with photo transects and image analysis (CPCe). Twenty-seven transects were surveyed from January to August 2012, in intensively impacted (I) open-access sites, in partially protected (P) sites with occasional, illegal trampling, and in a permanently closed (C) site. In I sites, total live cover was half the cover found in adjacent P sites. The area of bare rock averaged 53.6 and 25.0 % in I and P sites, respectively. In the C site, the area of bare rock was only 19.8 %. In I and P sites, macroalgae ( Palisada perforata) were dominating, while in the C site, the zoanthid Zoanthus sociatus was most abundant. Shell-bearing vermetids ( Petaloconchus varians) and bivalves ( Isognomon bicolor) were more abundant at the C site, being possible bioindicators for areas with zero or little trampling. Twelve years of total closure produced near-pristine communities in the C site, dominated by zoanthids and fragile mollusks. This study showed that trampling has severe and long-lasting consequences for the structure of these ecosystems.

  7. Current and potential impacts of mosquitoes and the pathogens they vector in the Pacific region

    Science.gov (United States)

    LaPointe, Dennis

    2007-01-01

    Mosquitoes and the pathogens they transmit are ubiquitous throughout most of the temperate and tropical regions of the world. The natural and pre-European distribution and diversity of mosquitoes and mosquito-borne diseases throughout much of the Pacific region, however, depicts a depauperate and relatively benign fauna reinforcing the dream of “paradise regained”. In the central and South Pacific few mosquito species were able to colonize the remotest islands and atolls. Native mosquitoes are limited to a few far-ranging species and island endemics are typically restricted to the genera of Aedes and Culex. Only lymphatic filariasis appears to have been present as an endemic mosquito-borne disease before European contact. In nearby Australia, however, some 242 species of mosquitoes are known to occur and more than 70 arboviruses have been identified (Mackenzie 1999). In this regard Australia is more similar to the rest of the tropic and subtropical world than the smaller islands of Oceania. In our ever-shrinking world of global commerce, military activity and travel, the nature of mosquito-borne disease in the Pacific was bound to change. This paper is a brief summary of introduced mosquitoes in the Pacific and their potential impacts on human and wildlife health.

  8. Impact of radiation embrittlement on integrity of pressure vessel supports for two PWR plants

    Energy Technology Data Exchange (ETDEWEB)

    Cheverton, R.D.; Pennell, W.E.; Robinson, G.C.; Nanstad, R.K.

    1989-01-01

    Recent data from the HFIR vessel surveillance program indicate a substantial radiation embrittlement rate effect at low irradiation temperatures (/approximately/120/degree/F) for A212-B, A350-LF3, A105-II, and corresponding welds. PWR vessel supports are fabricated of similar materials and are subjected to the same low temperatures and fast neutron fluxes (10/sup 8/ to 10/sup 9/ neutrons/cm/sup 2//center dot/s, E > 1.0 MeV) as those in the HFIR vessel. Thus, the embrittlement rate of these structures may be greater than previously anticipated. A study sponsored by the NRC is under way at ORNL to determine the impact of the rate effect on PWR vessel-support life expectancy. The scope includes the interpretation and application of the HFIR data, a survey of all light-water-reactor vessel support designs, and a structural and fracture-mechanics analysis of the supports for two specific PWR plants of particular interest with regard to a potential for support failure as a result of propagation of flaws. Calculations performed thus far indicate best-estimate critical flaw sizes, corresponding to 32 EFPY, of /approximately/0.2 in. for one plant and /approximately/0.4 in. for the other. These flaw sizes are small enough to be of concern. However, it appears that low-cycle fatigue is not a viable mechanism for creation of flaws of this size, and thus, presumably, such flaws would have to exist at the time of fabrication. 59 refs., 128 figs., 49 tabs.

  9. A RETROSPECTIVE STUDY OF THE IMPACT OF MEAN ARTERIAL PRESSURE ON ESTIMATED BLOOD LOSS DURING ENDOSCOPIC SINUS SURGERY

    Directory of Open Access Journals (Sweden)

    George W Williams

    2014-10-01

    Full Text Available The current practice of lowering mean arterial pressure (MAP during endoscopic sinus surgery (ESS is common, but unproven with regard to peer reviewed literature. The controlled hypotension induced is aimed for improved surgical field and lower the blood loss. Lower mean arterial pressures especially for prolonged surgeries may result in end organ hypoperfusion. The authors reviewed all patients who underwent outpatient endoscopic sinus surgery for the diagnosis of chronic sinusitis from January 1, 2012 to December 31, 2012 at Memorial Hermann Hospital – Texas Medical Centre. We individually reviewed case sheets of every patient and documented blood loss as recorded on the anaesthesia record or in the surgical procedure note, among other variables. A total of 326 patients were included in this study. The median estimated blood loss (EBL was found to be 50 ml. The multivariate regression analysis between these three groups showed that EBL was higher in MAP 75 group. The average of EBL in MAP75 group and the average of EBL in MAP 65-70 group is 42% higher than that in MAP>75 group when other variables were fixed. Hence we found the trend toward higher blood loss with lower MAP. The authors conclude that lower MAP does not result in lower EBL in endoscopic sinus surgery. Furthermore, increases in BMI and crystalloid administered during an aesthetic management of these cases correlates with increased estimate blood loss.

  10. Historic emergence, impact and current status of shrimp pathogens in the Americas.

    Science.gov (United States)

    Lightner, D V; Redman, R M; Pantoja, C R; Tang, K F J; Noble, B L; Schofield, P; Mohney, L L; Nunan, L M; Navarro, S A

    2012-06-01

    eastern USA via frozen commodity products and it reached the main shrimp farming countries of the Americas located on the Pacific side of the continents by the same mechanism in 1999. As is the case in Asia, WSD is the dominant disease problem of farmed shrimp in the Americas. The most recent disease to emerge in the Americas was infectious myonecrosis caused by IMN virus. As had happened before, within 3years of its discovery, the disease had been transferred to SE Asia with live P. vannamei, and because of its impact on the industry and potential for further spread in was listed by the OIE in 2005. Despite the huge negative impact of disease on the shrimp farming industry in the Americas, the industry has continued to grow and mature into a more sustainable industry. In marked contrast to 15-20years ago when PLs produced from wild adults and wild PLs were used to stock farms in the Americas, the industry now relies on domesticated lines of broodstock that have undergone selection for desirable characteristics including disease resistance.

  11. The impact on CT dose of the variability in tube current modulation technology: a theoretical investigation

    Science.gov (United States)

    Li, Xiang; Segars, W. Paul; Samei, Ehsan

    2014-08-01

    Body CT scans are routinely performed using tube-current-modulation (TCM) technology. There is notable variability across CT manufacturers in terms of how TCM technology is implemented. Some manufacturers aim to provide uniform image noise across body regions and patient sizes, whereas others aim to provide lower noise for smaller patients. The purpose of this study was to conduct a theoretical investigation to understand how manufacturer-dependent TCM scheme affects organ dose, and to develop a generic approach for assessing organ dose across TCM schemes. The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A ray-tracing method was developed to calculate the attenuation of the phantom for a given projection angle based on phantom anatomy, CT system geometry, x-ray energy spectrum, and bowtie filter filtration. The tube current (mA) for a given projection angle was then calculated as a log-linear function of the attenuation along that projection. The slope of this function, termed modulation control strength, α, was varied from 0 to 1 to emulate the variability in TCM technology. Using a validated Monte Carlo program, organ dose was simulated for five α values (α = 0, 0.25, 0.5, 0.75, and 1) in the absence and presence of a realistic system mA limit. Organ dose was further normalized by volume-weighted CT dose index (CTDIvol) to obtain conversion factors (h factors) that are relatively independent of system specifics and scan parameters. For both chest and abdomen-pelvis scans and for 24 radiosensitive organs, organ dose conversion factors varied with α, following second-order polynomial equations. This result suggested the need for α-specific organ dose conversion factors (i.e., conversion factors specific to the modulation scheme used). On the other hand, across the full range of α values, organ dose in a TCM scan could be derived from the conversion factors established for a fixed-mA scan (hFIXED). This was possible by

  12. Impact of neutrino properties on the estimation of inflationary parameters from current and future observations

    Science.gov (United States)

    Gerbino, Martina; Freese, Katherine; Vagnozzi, Sunny; Lattanzi, Massimiliano; Mena, Olga; Giusarma, Elena; Ho, Shirley

    2017-02-01

    We study the impact of assumptions about neutrino properties on the estimation of inflationary parameters from cosmological data, with a specific focus on the allowed contours in the ns/r plane, where ns is the scalar spectral index and r is the tensor-to-scalar ratio. We study the following neutrino properties: (i) the total neutrino mass Mν=∑i mi (where the index i =1 , 2, 3 runs over the three neutrino mass eigenstates); (ii) the number of relativistic degrees of freedom Neff at the time of recombination; and (iii) the neutrino hierarchy. Whereas previous literature assumed three degenerate neutrino masses or two massless neutrino species (approximations that clearly do not match neutrino oscillation data), we study the cases of normal and inverted hierarchy. Our basic result is that these three neutrino properties induce measurements are included, the standard contours in the ns/r plane are basically reproduced. Larger shifts of the contours in the ns/r plane (up to 0.8 σ ) arise for nonstandard values of Neff. We also provide forecasts for the future CMB experiments Cosmic Origins Explorer (COrE, satellite) and Stage-IV (ground-based) and show that the incomplete knowledge of neutrino properties, taken into account by a marginalization over Mν, could induce a shift of ˜0.4 σ toward lower values in the determination of ns (or a ˜0.8 σ shift if one marginalizes over Neff). Comparison to specific inflationary models is shown. Imperfect knowledge of neutrino properties must be taken into account properly, given the desired precision in determining whether or not inflationary models match the future data.

  13. CTD, current meter, pressure gauge, and wave spectra data from fixed platforms and other platforms from the Coastal Waters of California as part of the Santa Barbara Channel project from 27 April 1983 to 04 January 1985 (NODC Accession 8500177)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD, current meter, pressure gauge, and wave spectra data were collected from fixed platforms and other platforms from the Coastal Waters of California from 27 April...

  14. Current, pressure gauge, and other data from instruments attached to fixed platforms in the Bering Sea as part of the Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 16 September 1977 to 20 September 1978 (NODC Accession 8000024)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current, pressure gauge, and other data were collected from instruments attached to fixed platforms in the Bering Sea from the 16 September 1977 to 20 September...

  15. Study and Control of Various Corona Modes in an Atmospheric Pressure Weakly Ionized Plasma Reactor Using a Current Sensor Characterized by a Broad Frequency Band

    Science.gov (United States)

    Islam, Rokibul; Pedrow, Patrick; Lekobou, William; Englund, Karl

    2013-09-01

    A broad band current sensor is being used to monitor the various phenomena (primary streamers, secondary streamers, back corona, etc.) associated with an atmospheric pressure needle-array-to-grounded-screen corona discharge. The reactor consists of a PVC tube and the needle array consists of nickel coated steel electrodes with radius of curvature about 50 μ . The grounded screen is made from stainless steel mesh and applied voltage has a frequency of 60 Hz with an RMS value ranging from 0 to 10 kV. The voltage sensor is a resistive divider and the current sensor is a viewing resistor with value 50 Ω. The feed gas stream is presently (argon + acetylene) or (argon + oxygen) with the argon acting as carrier gas and the acetylene and oxygen acting as precursor gases. Voltage and current are captured with a LeCroy 9350AL 500MHz oscilloscope and analyzed with Matlab using digital signal processing algorithms. The goals of the research are 1) to measure reactor electrical power on a real time basis; 2) to provide real time control of the applied voltage and thus avoid spark conditions; and 3) to identify the various corona modes present in the reactor. Processing of substrates takes place downstream from the grounded screen, outside of the harsh corona discharge environment.

  16. Longitudinal impedance and wake from XFEL undulators. Impact on current-enhanced SASE schemes

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, G.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

    2007-06-15

    In this article we derive longitudinal impedance and wake function for an undulator setup with arbitrary undulator parameter, taking into account a finite transverse size of the electron bunch. Earlier studies considered a line density-distribution of electrons instead. We focus our attention on the long-wavelength asymptote (compared with resonance wavelength), at large distance of the electron bunch from the undulator entrance compared to the overtaking length, and for large vacuumchamber size compared to the typical transverse size of the field. These restrictions define a parameter region of interest for practical applications. We calculate a closed expression for impedance and wake function that may be evaluated numerically in the most general case. Such expression allows us to derive an analytical solution for a Gaussian transverse and longitudinal bunch shape. Finally, we study the feasibility of current-enhanced SASE schemes (ESASE) recently proposed for LCLS, that fall well-within our approximations. Numerical estimations presented in this paper indicate that impedance-induced energy spread is sufficient to seriously degrade the FEL performance. Our conclusion is in contrast with results in literature, where wake calculations for the LCLS case are given in free-space, as if the presence of the undulator were negligible. (orig.)

  17. The Current Crisis in Emergency Care and the Impact on Disaster Preparedness

    Directory of Open Access Journals (Sweden)

    Trainer Marcia

    2008-05-01

    Full Text Available Abstract Background The Homeland Security Act (HSA of 2002 provided for the designation of a critical infrastructure protection program. This ultimately led to the designation of emergency services as a targeted critical infrastructure. In the context of an evolving crisis in hospital-based emergency care, the extent to which federal funding has addressed disaster preparedness will be examined. Discussion After 9/11, federal plans, procedures and benchmarks were mandated to assure a unified, comprehensive disaster response, ranging from local to federal activation of resources. Nevertheless, insufficient federal funding has contributed to a long-standing counter-trend which has eroded emergency medical care. The causes are complex and multifactorial, but they have converged to present a severely overburdened system that regularly exceeds emergency capacity and capabilities. This constant acute overcrowding, felt in communities all across the country, indicates a nation at risk. Federal funding has not sufficiently prioritized the improvements necessary for an emergency care infrastructure that is critical for an all hazards response to disaster and terrorist emergencies. Summary Currently, the nation is unable to meet presidential preparedness mandates for emergency and disaster care. Federal funding strategies must therefore be re-prioritized and targeted in a way that reasonably and consistently follows need.

  18. Impacts of China's Current Appliance Standards and LabelingProgram to 2020

    Energy Technology Data Exchange (ETDEWEB)

    Fridley, David; Aden, Nathaniel; Zhou, Nan; Lin, Jiang

    2007-03-03

    The report summarizes the history and nature of China sstandardsand labeling program in the Introduction in Section 1. Trends indomestic production, exports, penetration rates, unit energy consumptionand the history of S&L technical levels by product are discussed ingreat detail in Section 2. The national energy impactsanalysis found inSection 3 concludes that overall China s standards and labeling programsreduce total electricity consumption in 2020 by an annual 106 TWh, or 16percent of what would otherwise been expected in that year in the absenceof standards and labeling programs.In total, the report concludes thatthe S&L programs currently in place in China are expected to save acumulative 1143 TWh by 2020, or 9 percent of the cumulative consumptionof residential electricity to that year. In 2020 alone, annual savingsare expected to be equivalent to 11 percent of residential electricityuse. In average generation terms, this is equivalent to 27 1-GW coalfired plants that would have required around 75 million tonnes of coal tooperate.In comparison, savings from the US appliance standards programalone is expected to save 10 percent of residential electricityconsumption in 2020.

  19. Lymph node-positive prostate cancer: current issues, emerging technology and impact on clinical outcome.

    Science.gov (United States)

    Adams, Julia; Cheng, Liang

    2011-09-01

    Lymph node metastasis in patients with prostate cancer indicates a poorer prognosis compared with patients without lymph node metastasis; however, some patients with node-positive disease have long-term survival. Many studies have attempted to discern what characteristics of lymph node metastasis are prognostically significant. These characteristics include nodal tumor volume, number of positive lymph nodes, lymph node density, extranodal extension, lymphovascular invasion and tumor dedifferentiation. Favorable characteristics of regional lymph node involvement included a smaller tumor size and smaller tumor volume. However, the current staging system for prostate cancer does not provide different subclassifications for patients with node-positive prostate cancer. In recent years numerous advanced technologies for the detection of lymph node metastasis have been developed, including molecular imaging techniques and the CellSearch Circulating Tumor Cell System. With the increased detection of patients with prostate cancer, emergence of new technology to identify lymph node metastasis and the number of radical prostatectomies being performed on the rise, subclassifying patients with lymph node-positive disease is imperative. Subclassification would provide a better picture of patient prognosis and allow for a better understanding of targeted therapies to treat patients with lymph node metastasis.