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Sample records for elevated pressures final

  1. Effects of selected thermophilic microorganisms on crude oils at elevated temperatures and pressures. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Premuzic, E.T.; Lin, M.S.

    1995-07-01

    During the past several years, a considerable amount of work has been carried out showing that microbially enhanced oil recovery (MEOR) is promising and the resulting biotechnology may be deliverable. At the Brookhaven National Laboratory (BNL), systematic studies have been conducted which dealt with the effects of thermophilic and thermoadapted bacteria on the chemical and physical properties of selected types of crude oils at elevated temperatures and pressures. Particular attention was paid to heavy crude oils from Venezuela, California, Alabama, Arkansas, Wyoming, Alaska, and other oil producing areas. Current studies indicate that during the biotreatment several chemical and physical properties of crude oils are affected. The oils are (1) emulsified; (2) acidified; (3) there is a qualitative and quantitative change in light and heavy fractions of the crudes; (4) there are chemical changes in fractions containing sulfur compounds; (5) there is an apparent reduction in the concentration of trace metals; (6) the qualitative and quantitative changes appear to be microbial species dependent; and (7) there is a distinction between {open_quotes}biodegraded{close_quotes} and {open_quotes}biotreated{close_quotes} oils. Preliminary results indicate the introduced microorganisms may become the dominant species in the bioconversion of oils. These studies also indicate the biochemical interactions between crude oils and microorganisms follow distinct trends, characterized by a group of chemical markers. Core-flooding experiments have shown significant additional crude oil recoveries are achievable with thermophilic microorganisms at elevated temperatures similar to those found in oil reservoirs. In addition, the biochemical treatment of crude oils has technological applications in downstream processing of crude oils such as in upgrading of low grade oils and the production of hydrocarbon based detergents.

  2. Entrained-flow gasification at elevated pressure: Volume 1: Final technical report, March 1, 1985-April 30,1987

    Energy Technology Data Exchange (ETDEWEB)

    Hedman, P.O.; Smoot, L.D.; Smith, P.J.; Blackham, A.U.

    1987-10-15

    The general purpose of this research program was to develop a basic understanding of the physical and chemical processes in entrained coal gasification and to use the results to improve and evaluate an entrained gasification computer model. The first task included the collection and analysis of in-situ gasifier data at elevated pressures with three coal types (North Dakota lignite, Wyoming subbituminous and Illinois bituminous), the design, construction, and testing of new coal/oxygen/steam injectors with a fourth coal type (Utah bituminous), the collection of supporting turbulent fluid dynamic (LDV) data from cold-flow studies, and the investigation of the feasibility of using laser-based (CARS) daignostic instruments to make measurements in coal flames. The second task included improvements to the two-dimensional gasifier submodels, tabulation and evaluation of new coal devolatilization and char oxidation data for predictions, fundamental studies of turbulent particle dispersion, the development of improved numerical methods, and validation of the comprehensive model through comparison of predictions with experimental results. The third task was to transfer technical advances to industry and to METC through technical seminars, production of a detailed data book, code placement, and publication of results. Research results for these three tasks are summarized briefly here and presented in detail in the body of the report and in supporting references. 202 refs., 73 figs., 23 tabs.

  3. Two-dimensional quantification of soot and flame-soot interaction in spray combustion at elevated pressures - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, T.

    2008-07-15

    Single-pulse time-resolved laser-induced incandescence (TiRe-LII) signal transients from soot particulates were acquired during unsteady high pressure Diesel combustion in a constant volume cell near top dead centre conditions typically found in a Diesel engine. Measurements were performed for initial gas pressures between 1 MPa and 3 MPa, injection pressures between 50 MPa and 130 MPa and laser probe timings between 5 ms and 16 ms after start of fuel injection. In separate experiments and for the same cell operating conditions, gas temperatures were deduced from spectrally resolved soot pyrometry measurements. Implementing the LII model of Kock et al. ensemble mean soot particle diameters were evaluated from least-squares fitting of theoretical cooling curves to experimental TiRe-LII signal transients. Since in the experiments the environmental gas temperature and the width of an assumed particle size distribution were not known, the effects of the initial choice of these parameters on retrieved particle diameters were investigated. It is shown that evaluated mean particle diameters are only slightly biased by the choice of typical size distribution widths and gas temperatures. For a fixed combustion phase mean particle diameters are not much affected by gas pressure, however they become smaller at high fuel injection pressure. At a mean chamber pressure of 1.4 MPa evaluated mean particle diameters increased by a factor of two for probe delays between 5 ms and 16 ms after start of injection, irrespective of the choices of first-guess fitting variables, indicating a certain robustness of data analysis procedure. (author)

  4. 78 FR 14697 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-03-07

    ... Communities affected elevation above ground [caret] Elevation in meters (MSL) Modified Cecil County, Maryland... 1 to Stone Run At the Stone Run +271 Town of Rising Sun, confluence. Unincorporated Areas of Cecil County. Approximately 460 feet +359 downstream of Pierce Road. Tributary 2 to Stone Run At the Stone Run...

  5. 75 FR 69892 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-11-16

    ...: * Elevation in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth... county +899 City of Norwich, Town boundary. of Greene, Town of North Norwich, Town of Oxford, Town of...). Susquehanna River At the downstream county +965 Town of Afton, Town of boundary. Bainbridge, Village of Afton...

  6. 77 FR 6980 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-02-10

    ... in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth in feet above ground [caret] Elevation in meters (MSL) Modified Unincorporated Areas of Nowata County... Bayou An area bounded by the +100 Town of Mayersville, county boundary to the Unincorporated Areas of...

  7. 76 FR 1535 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-01-11

    ... in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth in feet above ground [caret] Elevation in meters (MSL) Modified Unincorporated Areas of Poinsett County... with the St. Francis River...... +212 Areas of Poinsett County. Approximately 0.45 mile downstream of...

  8. 75 FR 68710 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-11-09

    ...: * Elevation in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth... County, California Docket Nos.: FEMA-B-7762, FEMA-B-7795, and FEMA-B-1053 California Unincorporated Oregon Slough..... City of Montague +2503 Areas of Siskiyou and County. Unincorporated Siskiyou County...

  9. 76 FR 50918 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-08-17

    ... in feet (NGVD) + Elevation in feet (NAVD) Depth in feet State City/town/county Source of flooding... affected [caret] Elevation in meters (MSL) Modified Jones County, Texas, and Incorporated Areas Docket No.: FEMA-B-1122 Lake Fort Phantom Hill Just downstream of County +1642 City of Abilene, Highway 1082...

  10. 78 FR 10066 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-02-13

    ... follows: * Elevation in feet (NGVD) + Elevation in feet (NAVD) Depth in feet State City/town/county Source...). Scriba Creek Approximately 0.90 mile +546 Town of Amboy. upstream of County Route 23 (Potter Road.... Town of Palermo Maps are available for inspection at the Palermo Town Municipal Offices, 53 County...

  11. 77 FR 49379 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-08-16

    ... in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth in feet above ground [caret] Elevation in meters (MSL) Modified Unincorporated Areas of Washington County... of the +35 Areas of railroad. Washington County. Approximately 2.1 miles upstream of the railroad...

  12. 75 FR 43418 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-07-26

    ... follows: * Elevation in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding... +869 Town of Peoria, upstream of Main Street. Unincorporated Areas of Ottawa County. Approximately 1.... Town of Peoria Maps are available for inspection at the Ottawa County Courthouse, 102 East Central...

  13. 78 FR 21272 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-04-10

    ... below for the modified BFEs for each community listed. These modified elevations have been published in... [Amended] 0 2. The tables published under the authority of Sec. 67.11 are amended as follows: * Elevation... Austin. upstream of 29th Avenue Southwest (County Highway 28). At the downstream side of +1205 I and M...

  14. Investigations of Sooting Laminar Coflow Diffusion Flames at Elevated Pressures

    KAUST Repository

    Steinmetz, Scott A.

    2016-12-01

    Soot is a common byproduct of hydrocarbon based combustion systems. It poses a risk to human and environmental health, and can negatively or positively affect combustor performance. As a result, there is significant interest in understanding soot formation in order to better control it. More recently, the need to study soot formation in engine relevant conditions has become apparent. One engine relevant parameter that has had little focus is the ambient pressure. This body of work focuses on the formation of soot in elevated pressure environments, and a number of investigations are carried out with this purpose. Laminar coflow diffusion flames are used as steady, simple soot producers. First, a commonly studied flame configuration is further characterized. Coflow flames are frequently used for fundamental flame studies, particularly at elevated pressures. However, they are more susceptible to buoyancy induced instabilities at elevated pressures. The velocity of the coflow is known to have an effect on flame stability and soot formation, though these have not been characterized at elevated pressures. A series of flames are investigated covering a range of flowrates, pressures, and nozzle diameters. The stability limits of coflow flames in this range is investigated. Additionally, an alternative strategy for scaling these flames to elevated pressures is proposed. Finally, the effect of coflow rate on soot formation is evaluated. Identification of fundamental flames for coordinated research can facilitate our understanding of soot formation. The next study of this work focuses on adding soot concentration and particle size information to an existing fundamental flame dataset for the purpose of numerical model validation. Soot volume fraction and average particle diameters are successfully measured in nitrogen-diluted ethylene-air laminar coflow flames at pressures of 4, 8, 12, and 16 atm. An increase in particle size with pressure is found up to 12 atm, where particle

  15. 77 FR 21471 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-04-10

    ... elevations have been published in newspapers of local circulation and ninety (90) days have elapsed since... School Creek. Approximately 0.61 mile +605 upstream of the confluence with School Creek. Arkansas River...

  16. Elevated preoperative blood pressures in adult surgical patients are highly predictive of elevated home blood pressures.

    Science.gov (United States)

    Schonberger, Robert B; Nwozuzu, Adambeke; Zafar, Jill; Chen, Eric; Kigwana, Simon; Monteiro, Miriam M; Charchaflieh, Jean; Sophanphattana, Sophisa; Dai, Feng; Burg, Matthew M

    2018-04-01

    Blood pressure (BP) measurement during the presurgical assessment has been suggested as a way to improve longitudinal detection and treatment of hypertension. The relationship between BP measured during this assessment and home blood pressure (HBP), a better indicator of hypertension, is unknown. The purpose of the present study was to determine the positive predictive value of presurgical BP for predicting elevated HBP. We prospectively enrolled 200 patients at a presurgical evaluation clinic with clinic blood pressures (CBPs) ≥130/85 mm Hg, as measured using a previously validated automated upper-arm device (Welch Allyn Vital Sign Monitor 6000 Series), to undergo daily HBP monitoring (Omron Model BP742N) between the index clinic visit and their day of surgery. Elevated HBP was defined, per American Heart Association guidelines, as mean systolic HBP ≥135 mm Hg or mean diastolic HBP ≥85 mm Hg. Of the 200 participants, 188 (94%) returned their home blood pressure monitors with valid data. The median number of HBP recordings was 10 (interquartile range, 7-14). Presurgical CBP thresholds of 140/90, 150/95, and 160/100 mm Hg yielded positive predictive values (95% confidence interval) for elevated HBP of 84.1% (0.78-0.89), 87.5% (0.81-0.92), and 94.6% (0.87-0.99), respectively. In contrast, self-reported BP control, antihypertensive treatment, availability of primary care, and preoperative pain scores demonstrated poor agreement with elevated HBP. Elevated preoperative CBP is highly predictive of longitudinally elevated HBP. BP measurement during presurgical assessment may provide a way to improve longitudinal detection and treatment of hypertension. Copyright © 2018 American Heart Association. Published by Elsevier Inc. All rights reserved.

  17. Blood pressure modifies retinal susceptibility to intraocular pressure elevation.

    Directory of Open Access Journals (Sweden)

    Zheng He

    Full Text Available Primary open angle glaucoma affects more than 67 million people. Elevated intraocular pressure (IOP is a risk factor for glaucoma and may reduce nutrient availability by decreasing ocular perfusion pressure (OPP. An interaction between arterial blood pressure and IOP determines OPP; but the exact contribution that these factors have for retinal function is not fully understood. Here we sought to determine how acute modifications of arterial pressure will affect the susceptibility of neuronal function and blood flow to IOP challenge. Anaesthetized (ketamine:xylazine Long-Evan rats with low (∼60 mmHg, sodium nitroprusside infusion, moderate (∼100 mmHg, saline, or high levels (∼160 mmHg, angiotensin II of mean arterial pressure (MAP, n = 5-10 per group were subjected to IOP challenge (10-120 mmHg, 5 mmHg steps every 3 minutes. Electroretinograms were measured at each IOP step to assess bipolar cell (b-wave and inner retinal function (scotopic threshold response or STR. Ocular blood flow was measured using laser-Doppler flowmetry in groups with similar MAP level and the same IOP challenge protocol. Both b-wave and STR amplitudes decreased with IOP elevation. Retinal function was less susceptible to IOP challenge when MAP was high, whereas the converse was true for low MAP. Consistent with the effects on retinal function, higher IOP was needed to attenuated ocular blood flow in animals with higher MAP. The susceptibility of retinal function to IOP challenge can be ameliorated by acute high BP, and exacerbated by low BP. This is partially mediated by modifications in ocular blood flow.

  18. 76 FR 3524 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-01-20

    ... effects from Kentucky River). the Kentucky River to Garrard County. approximately 932 feet upstream of Old..., City of The Colony, Town of Hebron, Unincorporated Areas of Denton County. Approximately 2,940 feet... Communities affected [caret] Elevation in meters (MSL) Modified Ashley County, Arkansas, and Incorporated...

  19. 76 FR 68107 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-11-03

    ... environmental impact assessment has not been prepared. Regulatory Flexibility Act. As flood elevation..., Illinois, and Incorporated Areas Docket No.: FEMA-B-1134 Beaver Creek Approximately 1.58 miles +366... of Main Street extended (River Mile 887). Unnamed Tributary to Beaver Creek Approximately 1,500 feet...

  20. The hidden magnitude of raised blood pressure and elevated blood ...

    African Journals Online (AJOL)

    Conclusions: The prevalence of undiagnosed raised blood pressure and elevated blood sugar was high in Ethiopia and only very small percentage of people had been aware of their high blood pressure and elevated blood sugar. Policy makers in the health sector including other health development partners need to ...

  1. Cerebral Pulsatility Index Is Elevated in Patients with Elevated Right Atrial Pressure.

    Science.gov (United States)

    Lahiri, Shouri; Schlick, Konrad H; Padrick, Matthew M; Rinsky, Brenda; Gonzalez, Nestor; Jones, Heather; Mayer, Stephan A; Lyden, Patrick D

    2018-01-01

    Extracerebral venous congestion can precipitate intracranial hypertension due to obstruction of cerebral blood outflow. Conditions that increase right atrial pressure, such as hypervolemia, are thought to increase resistance to jugular venous outflow and contribute to cerebro-venous congestion. Cerebral pulsatility index (CPI) is considered a surrogate marker of distal cerebrovascular resistance and is elevated with intracranial hypertension. Thus, we sought to test the hypothesis that elevated right atrial pressure is associated with increased CPI compared to normal right atrial pressure. We retrospectively reviewed 61 consecutive patients with subarachnoid hemorrhage. We calculated CPI from transcranial Doppler studies and correlated these with echocardiographic measures of right atrial pressure. CPIs were compared from patients with elevated and normal right atrial pressure. There was a significant difference between CPI obtained from all patients with elevated right atrial pressure compared to those with normal right atrial pressure (P right and left hemispheric CPI from patients with both elevated and normal right atrial pressure. Patients with elevated right atrial pressure had significantly higher CPI compared to patients with normal right atrial pressure. These findings suggest that cerebro-venous congestion due to impaired jugular venous outflow may increase distal cerebrovascular resistance as measured by CPI. Since elevated CPI is associated with poor outcome in numerous neurological conditions, future studies are needed to elucidate the significance of these results in other populations. Copyright © 2017 by the American Society of Neuroimaging.

  2. Biomarkers Prognostic for Elevated Intracranial Pressure

    Science.gov (United States)

    2016-03-01

    Orthopedic injury (n=20) iii) Exclusion of patients with polytrauma . It has been reported that serum ceruloplasmin (as well as copper) levels...inclusion of polytrauma patients in our results. We therefore identified the TBI patients with isolated head trauma, and compared the recorded...ceruloplasmin values between those with elevated ICP and those without. Figure 13 shows that when the patients with polytrauma were excluded from the

  3. Microbiological methane production at elevated pressure

    International Nuclear Information System (INIS)

    Friedmann, H.; Maerkl, H.

    1994-01-01

    Taking the fermentation of waste water from the production of baker's yest as an example, experimental and theoretical examinations of a qualitative and quantitative listing of the effects of pressure on the microbiological methane production are presented. As the waste water used for the experiments was very rich in sulphates, the influence of the hydrogen sulphide constituted from those played a particularly important role. Experiments showed that the essential influence of pressure is constituted by the increased solubility of the produced gases. The increased quantities of dissolved carbon dioxide in particular result in a lowering of the pH-value with increasing pressure. The gas composition changes at the same time. The higher the pressure the higher also the portion of methane contained in the biogas but the lower the portions of carbon dioxide and hydrogen sulphide. Experimental findings could be represented comparatively well by a mathematical model. This points at the fact that the physical and chemical working mechanisms were grasped correctly by the model. The mathematical description helped much to increase the understanding of the physical and chemical working mechanisms in biogas reactors. This understanding makes it possible for the developer as well as for the operator of biogas installations to control the process by constructive measures and mearuses concerning operation technology. (orig.) [de

  4. Haemodynamic patterns in ST-elevation myocardial infarction : incidence and correlates of elevated filling pressures

    NARCIS (Netherlands)

    Bergstra, A.; Svilaas, T.; van Veldhuisen, D. J.; van den Heuvel, A. F. M.; van der Horst, I. C. C.; Zijlstra, F.

    Objectives. We sought to study the incidence and clinical correlates of elevated filling pressures in ST-elevation myocardial infarction (STEMI) patients, without physical signs of heart failure and treated with primary coronary angioplasty. Background. Haemodynamic data, as measured with a

  5. Patterns of care and persistence after incident elevated blood pressure.

    Science.gov (United States)

    Daley, Matthew F; Sinaiko, Alan R; Reifler, Liza M; Tavel, Heather M; Glanz, Jason M; Margolis, Karen L; Parker, Emily; Trower, Nicole K; Chandra, Malini; Sherwood, Nancy E; Adams, Kenneth; Kharbanda, Elyse O; Greenspan, Louise C; Lo, Joan C; O'Connor, Patrick J; Magid, David J

    2013-08-01

    Screening for hypertension in children occurs during routine care. When blood pressure (BP) is elevated in the hypertensive range, a repeat measurement within 1 to 2 weeks is recommended. The objective was to assess patterns of care after an incident elevated BP, including timing of repeat BP measurement and likelihood of persistently elevated BP. This retrospective study was conducted in 3 health care organizations. All children aged 3 through 17 years with an incident elevated BP at an outpatient visit during 2007 through 2010 were identified. Within this group, we assessed the proportion who had a repeat BP measured within 1 month of their incident elevated BP and the proportion who subsequently met the definition of hypertension. Multivariate analyses were used to identify factors associated with follow-up BP within 1 month of initial elevated BP. Among 72,625 children and adolescents in the population, 6108 (8.4%) had an incident elevated BP during the study period. Among 6108 with an incident elevated BP, 20.9% had a repeat BP measured within 1 month. In multivariate analyses, having a follow-up BP within 1 month was not significantly more likely among individuals with obesity or stage 2 systolic elevation. Among 6108 individuals with an incident elevated BP, 84 (1.4%) had a second and third consecutive elevated BP within 12 months. Whereas >8% of children and adolescents had an incident elevated BP, the great majority of BPs were not repeated within 1 month. However, relatively few individuals subsequently met the definition of hypertension.

  6. Full characterization of multiphase, multimorphological kinetics in flow-induced crystallization of IPP at elevated pressure

    NARCIS (Netherlands)

    Troisi, E.M.; Caelers, H.J.M.; Peters, G.W.M.

    2017-01-01

    Understanding the complex crystallization behavior of isotactic polypropylene (iPP) in conditions comparable to those found in polymer processing, where the polymer melt experiences a combination of high shear rates and elevated pressures, is key for modeling and therefore predicting the final

  7. Elevated arterial blood pressure after superior cavo-pulmonary anastomosis is associated with elevated pulmonary artery pressure and cerebrovascular dysautoregulation.

    Science.gov (United States)

    Cabrera, Antonio G; Kibler, Kathleen K; Blaine Easley, R; Goldsworthy, Michelle; Shekerdemian, Lara S; Andropoulos, Dean B; Heinle, Jeffrey; Gottlieb, Erin A; Vu, Eric; Brady, Ken M

    2018-04-18

    BackgroundElevated arterial blood pressure (ABP) is common after superior bidirectional cavopulmonary anastomosis (BCPA). The effects of elevated ABP after BCPA on cerebrovascular hemodynamics are unknown. We sought to determine the relationship between elevated ABP and cerebrovascular autoregulation after BCPA.MethodsProspective, observational study on infants with single-ventricle physiology after BCPA surgery. Continuous recordings of mean ABP, mean cavopulmonary artery pressure (PAP), near-infrared spectroscopy measures of cerebral oximetry (regional cerebral oxygen saturation (rSO 2 )), and relative cerebral blood volume index were obtained from admission to extubation. Autoregulation was measured as hemoglobin volume index (HVx). Physiologic variables, including the HVx, were tested for variance across ABP.ResultsSixteen subjects were included in the study. Elevated ABP post-BCPA was associated with both, elevated PAP (PABP and alterations in rSO 2 . Using piecewise regression, the relationship of PAP to ABP demonstrated a breakpoint at 68 mm Hg (interquartile range (IQR) 62-70 mm Hg). Curve fit of HVx as a function of ABP identified optimal ABP supporting robust autoregulation at a median ABP of 55 mm Hg (IQR 51-64 mm Hg).ConclusionsElevated ABP post-BCPA is associated with cerebrovascular dysautoregulation, and elevated PAP. The effects, of prolonged dysautoregulation within this population, require further study.Pediatric Research advance online publication, 18 April 2018; doi:10.1038/pr.2018.31.

  8. Measurement of rock properties at elevated pressures and temperatures

    International Nuclear Information System (INIS)

    Pincus, H.J.; Hoskins, E.R.

    1985-01-01

    The papers in this volume were presented at an ASTM symposium held on 20 June 1983 in conjunction with the 24th Annual Rock Mechanics Symposium at Texas A and M University, College Station, TX. The purpose of these papers is to present recent developments in the measurement of rock properties at elevated pressures and temperatures, and to examine and interpret the data produced by such measurement. The need for measuring rock properties at elevated pressures and temperatures has become increasingly important in recent years. Location and design of nuclear waste repositories, development of geothermal energy sites, and design and construction of deep excavations for civil, military, and mining engineering require significantly improved capabilities for measuring rock properties under conditions substantially different from those prevailing in most laboratory and in situ work. The development of high-pressure, high-temperature capabilities is also significant for the analysis of tectonic processes

  9. PWR [pressurized water reactor] pressurizer transient response: Final report

    International Nuclear Information System (INIS)

    Murphy, S.I.

    1987-08-01

    To predict PWR pressurizer transients, Ahl proposed a three region model with a universal coefficient to represent condensation on the water surface. Specifically, this work checks the need for three regions and the modeling of the interfacial condensation coefficient. A computer model has been formulated using the basic mass and energy conservation laws. A two region vapor and liquid model was first used to predict transients run on a one-eleventh scale Freon pressurizer. These predictions verified the need for a second liquid region. As a result, a three region model was developed and used to predict full-scale pressurizer transients at TMI-2, Shippingport, and Stade. Full-scale pressurizer predictions verified the three region model and pointed out the shortcomings of Ahl's universal condensation coefficient. In addition, experiments were run using water at low pressure to study interface condensation. These experiments showed interface condensation to be significant only when spray flow is turned on; this result was incorporated in the final three region model

  10. Investigating Soot Morphology in Counterflow Flames at Elevated Pressures

    KAUST Repository

    Amin, Hafiz Muhammad Fahid

    2018-01-01

    Practical combustion devices such as gas turbines and diesel engines operate at high pressures to increase their efficiency. Pressure significantly increases the overall soot yield. Morphology of these ultra-fine particles determines their airborne lifetime and their interaction with the human respiratory system. Therefore, investigating soot morphology at high pressure is of practical relevance. In this work, a novel experimental setup has been designed and built to study the soot morphology at elevated pressures. The experimental setup consists of a pressure vessel, which can provide optical access from 10° to 165° for multi-angle light scattering, and a counterflow burner which produces laminar flames at elevated pressures. In the first part of the study, N2-diluted ethylene/air and ethane air counterflow flames are stabilized from 2 to 5 atm. Two-angle light scattering and extinction technique have been used to study the effects of pressure on soot parameters. Path averaged soot volume fraction is found to be very sensitive to pressure and increased significantly from 2 to 5 atm. Primary particle size and aggregate size also increased with pressure. Multi-angle light scattering is also performed and flames are investigated from 3 to 5 atm. Scattering to absorption ratio is calculated from multi-angle light scattering and extinction data. Scattering to absorption ratio increased with pressure whereas the number of primary particles in an aggregate decreased with increasing pressure. In the next part of the study, Thermophoretic Sampling of soot is performed, in counterflow flames from 3 to 10 atm, followed by transmission electron microscopy. Mean primary particle size increased with pressure and these trends are consistent withour light scattering measurements. Fractal properties of soot aggregates are found to be insensitive to pressure. 2D diffused light line of sight attenuation (LOSA) and Laser Induced Incandescence (LII) are used to measure local soot

  11. On Boiling of Crude Oil under Elevated Pressure

    Science.gov (United States)

    Pimenova, Anastasiya V.; Goldobin, Denis S.

    2016-02-01

    We construct a thermodynamic model for theoretical calculation of the boiling process of multicomponent mixtures of hydrocarbons (e.g., crude oil). The model governs kinetics of the mixture composition in the course of the distillation process along with the boiling temperature increase. The model heavily relies on the theory of dilute solutions of gases in liquids. Importantly, our results are applicable for modelling the process under elevated pressure (while the empiric models for oil cracking are not scalable to the case of extreme pressure), such as in an oil field heated by lava intrusions.

  12. Pressure buffering by the tympanic membrane. In vivo measurements of middle ear pressure fluctuations during elevator motion.

    Science.gov (United States)

    Padurariu, Simona; de Greef, Daniël; Jacobsen, Henrik; Nlandu Kamavuako, Ernest; Dirckx, Joris J; Gaihede, Michael

    2016-10-01

    The tympanic membrane (TM) represents a pressure buffer, which contributes to the overall pressure regulation of the middle ear (ME). This buffer capacity is based on its viscoelastic properties combined with those of the attached ossicular chain, muscles and ligaments. The current work presents a set of in vivo recordings of the ME pressure variations normally occurring in common life: elevator motion. This is defined as a situation of smooth ambient pressure increase or decrease on a limited range and at a low rate of pressure change. Based on these recordings, the purpose was a quantitative analysis of the TM buffer capacity including the TM compliance. The pressure changes in seven normal adult ME's with intact TM's were continuously recorded directly inside the ME cavity during four different elevator trips using a high precision instrument. The TM buffer capacity was determined by the ratio between the changes in ME and the ambient pressure. Further, the ME volumes were calculated by Boyle's Law from pressure recordings during inflation-deflation tests; subsequently the TM compliance could also be calculated. Finally, the correlation between the ME volume and buffer function was determined. Twenty-one elevator trips could be used for the analysis. The overall mean TM pressure buffering capacity was 23.3% (SEM = 3.4), whereas the mean overall compliance was 28.9 × 10 -3  μL/Pa (SEM = 4.8). A strong negative linear correlation was found between the TM buffer capacity and the ME volumes (R 2  = 0.92). These results were in fair agreement with the literature obtained in clinical as well as temporal bone experiments, and they provide an in vivo reference for the normal ME function as well as for ME modeling. The TM buffer capacity was found more efficient in smaller mastoids. Possible clinical implications are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Elevated cerebrospinal fluid pressure in patients with Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Fellmann Jere

    2006-05-01

    Full Text Available Abstract Background Abnormalities in cerebrospinal fluid (CSF production and turnover, seen in normal pressure hydrocephalus (NPH and in Alzheimer's disease (AD, may be an important cause of amyloid retention in the brain and may relate the two diseases. There is a high incidence of AD pathology in patients being shunted for NPH, the AD-NPH syndrome. We now report elevated CSF pressure (CSFP, consistent with very early hydrocephalus, in a subset of AD patients enrolled in a clinical trial of chronic low-flow CSF drainage. Our objective was to determine the frequency of elevated CSFP in subjects meeting National Institutes of Neurological and Communicative Diseases and Stroke – Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA criteria for AD, excluding those with signs of concomitant NPH. Methods AD subjects by NINCDS-ADRDA criteria (n = 222, were screened by history, neurological examination, and radiographic imaging to exclude those with clinical or radiographic signs of NPH. As part of this exclusion process, opening CSFP was measured supine under general anesthesia during device implantation surgery at a controlled pCO2 of 40 Torr (40 mmHg. Results Of the 222 AD subjects 181 had pressure measurements recorded. Seven subjects (3.9% enrolled in the study had CSFP of 220 mmH20 or greater, mean 249 ± 20 mmH20 which was significantly higher than 103 ± 47 mmH2O for the AD-only group. AD-NPH patients were significantly younger and significantly less demented on the Mattis Dementia Rating Scale (MDRS. Conclusion Of the AD subjects who were carefully screened to exclude those with clinical NPH, 4% had elevated CSFP. These subjects were presumed to have the AD-NPH syndrome and were withdrawn from the remainder of the study.

  14. Burst pressure of super duplex stainless steel pipes subject to combined axial tension, internal pressure and elevated temperature

    International Nuclear Information System (INIS)

    Lasebikan, B.A.; Akisanya, A.R.

    2014-01-01

    The burst pressure of super duplex stainless steel pipe is measured under combined internal pressure, external axial tension and elevated temperature up to 160 °C. The experimental results are compared with existing burst pressure prediction models. Existing models are found to provide reasonable estimate of the burst pressure at room temperature but significantly over estimate the burst pressure at elevated temperature. Increasing externally applied axial stress and elevated temperature reduces the pressure capacity. - Highlights: • The burst pressure of super duplex steel is measured under combined loading. • Effect of elevated temperature on burst pressure is determined. • Burst pressure decreases with increasing temperature. • Existing models are reliable at room temperature. • Burst strength at elevated temperature is lower than predictions

  15. Evaluation Of Liner Back-pressure Due To Concrete Pore Pressure At Elevated Temperatures

    International Nuclear Information System (INIS)

    James, R.J.; Rashid, Y.R.; Liu, A.S.; Gou, B.

    2006-01-01

    GE's latest evolution of the boiling water reactor, the ESBWR, has innovative passive design features that reduce the number and complexity of active systems, which in turn provide economic advantages while also increasing safety. These passive systems used for emergency cooling also mean that the primary containment system will experience elevated temperatures with longer durations than conventional plants in the event of design basis accidents. During a Loss of Coolant Accident (LOCA), the drywell in the primary containment structure for the ESBWR will be exposed to saturated steam conditions for up to 72 hours following the accident. A containment spray system may be activated that sprays the drywell area with water to condense the steam as part of the recovery operations. The liner back-pressure will build up gradually over the 72 hours as the concrete temperatures increase, and a sudden cool down could cause excessive differential pressure on the liner to develop. For this analysis, it is assumed that the containment spray is activated at the end of the 72-hour period. A back-pressure, acting between the liner and the concrete wall of the containment, can occur as a result of elevated temperatures in the concrete causing steam and saturated vapor pressures to develop from the free water remaining in the pores of the concrete. Additional pore pressure also develops under the elevated temperatures from the non-condensable gases trapped in the concrete pores during the concrete curing process. Any buildup of this pore pressure next to the liner, in excess of the drywell internal pressure, will act to push the liner away from the concrete with a potential for tearing at the liner anchorages. This paper describes the methods and analyses used to quantify this liner back-pressure so that appropriate measures are included in the design of the liner and anchorage system. A pore pressure model is developed that calculates the pressure distribution across the concrete

  16. Reactor pressure elevation preventing device upon interruption of load

    International Nuclear Information System (INIS)

    Ota, Yasuo; Okukawa, Ryutaro.

    1996-01-01

    In a power load imbalance circuit of a steam turbine control device, a power load imbalance occurrence signal is outputted for a predetermined period of time upon occurrence of load interruption. A function for suppressing increase of number of rotation of a turbine due to load interruption is not disturbed, and the power load imbalance circuit is not operated at least after a primary peak where the number of rotation of the turbine is increased. Since a steam control valve flow rate demand signal and a turbine bypass valve flow rate demand signals are corporated subsequently to control the opening degree of the steam control valve and the turbine bypass valve, elevation of reactor pressure is always suppressed and maintained constant, as well as abrupt opening of the steam control valve due to cancel of the power load imbalance circuit when steam control valve opening demand is outputted can be prevented. (N.H.)

  17. Soot particle size measurements in ethylene diffusion flames at elevated pressures

    KAUST Repository

    Steinmetz, Scott; Fang, Tiegang; Roberts, William L.

    2016-01-01

    for the first time at elevated pressures. Soot volume fraction dependence on pressure is consistent with the observations of similar studies, scaling approximately with the square of pressure. Scattering intensity is analyzed through Rayleigh and Rayleigh

  18. Left ventricular filling under elevated left atrial pressure

    Science.gov (United States)

    Gaddam, Manikantam; Samaee, Milad; Santhanakrishnan, Arvind

    2017-11-01

    Left atrial pressure (LAP) is elevated in diastolic dysfunction, where left ventricular (LV) filling is impaired due to increase in ventricular stiffness. The impact of increasing LAP and LV stiffness on intraventricular filling hemodynamics remains unclear. We conducted particle image velocimetry and hemodynamics measurements in a left heart simulator (LHS) under increasing LAP and LV stiffness at a heart rate of 70 bpm. The LHS consisted of a flexible-walled LV physical model fitted within a fluid-filled chamber. LV wall motion was generated by a piston pump that imparted pressure fluctuations in the chamber. Resistance and compliance elements in the flow loop were adjusted to obtain bulk physiological hemodynamics in the least stiff LV model. Two LV models of increasing stiffness were subsequently tested under unchanged loop settings. LAP was varied between 5-20 mm Hg for each LV model, by adjusting fluid level in a reservoir upstream of the LV. For constant LV stiffness, increasing LAP lowered cardiac output (CO), while ejection fraction (EF) and E/A ratio were increased. For constant LAP, increasing LV stiffness lowered CO and EF, and increased E/A ratio. The implications of these altered hemodynamics on intraventricular filling vortex characteristics will be presented.

  19. Rotating disk electrode system for elevated pressures and temperatures.

    Science.gov (United States)

    Fleige, M J; Wiberg, G K H; Arenz, M

    2015-06-01

    We describe the development and test of an elevated pressure and temperature rotating disk electrode (RDE) system that allows measurements under well-defined mass transport conditions. As demonstrated for the oxygen reduction reaction on polycrystalline platinum (Pt) in 0.5M H2SO4, the setup can easily be operated in a pressure range of 1-101 bar oxygen, and temperature of 140 °C. Under such conditions, diffusion limited current densities increase by almost two orders of magnitude as compared to conventional RDE setups allowing, for example, fuel cell catalyst studies under more realistic conditions. Levich plots demonstrate that the mass transport is indeed well-defined, i.e., at low electrode potentials, the measured current densities are fully diffusion controlled, while at higher potentials, a mixed kinetic-diffusion controlled regime is observed. Therefore, the setup opens up a new field for RDE investigations under temperature and current density conditions relevant for low and high temperature proton exchange membrane fuel cells.

  20. Rotating disk electrode system for elevated pressures and temperatures

    International Nuclear Information System (INIS)

    Fleige, M. J.; Wiberg, G. K. H.; Arenz, M.

    2015-01-01

    We describe the development and test of an elevated pressure and temperature rotating disk electrode (RDE) system that allows measurements under well-defined mass transport conditions. As demonstrated for the oxygen reduction reaction on polycrystalline platinum (Pt) in 0.5M H 2 SO 4 , the setup can easily be operated in a pressure range of 1–101 bar oxygen, and temperature of 140 °C. Under such conditions, diffusion limited current densities increase by almost two orders of magnitude as compared to conventional RDE setups allowing, for example, fuel cell catalyst studies under more realistic conditions. Levich plots demonstrate that the mass transport is indeed well-defined, i.e., at low electrode potentials, the measured current densities are fully diffusion controlled, while at higher potentials, a mixed kinetic-diffusion controlled regime is observed. Therefore, the setup opens up a new field for RDE investigations under temperature and current density conditions relevant for low and high temperature proton exchange membrane fuel cells

  1. Rotating disk electrode system for elevated pressures and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Fleige, M. J.; Wiberg, G. K. H.; Arenz, M. [Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 Ø Copenhagen (Denmark)

    2015-06-15

    We describe the development and test of an elevated pressure and temperature rotating disk electrode (RDE) system that allows measurements under well-defined mass transport conditions. As demonstrated for the oxygen reduction reaction on polycrystalline platinum (Pt) in 0.5M H{sub 2}SO{sub 4}, the setup can easily be operated in a pressure range of 1–101 bar oxygen, and temperature of 140 °C. Under such conditions, diffusion limited current densities increase by almost two orders of magnitude as compared to conventional RDE setups allowing, for example, fuel cell catalyst studies under more realistic conditions. Levich plots demonstrate that the mass transport is indeed well-defined, i.e., at low electrode potentials, the measured current densities are fully diffusion controlled, while at higher potentials, a mixed kinetic-diffusion controlled regime is observed. Therefore, the setup opens up a new field for RDE investigations under temperature and current density conditions relevant for low and high temperature proton exchange membrane fuel cells.

  2. Rotating disk electrode system for elevated pressures and temperatures

    Science.gov (United States)

    Fleige, M. J.; Wiberg, G. K. H.; Arenz, M.

    2015-06-01

    We describe the development and test of an elevated pressure and temperature rotating disk electrode (RDE) system that allows measurements under well-defined mass transport conditions. As demonstrated for the oxygen reduction reaction on polycrystalline platinum (Pt) in 0.5M H2SO4, the setup can easily be operated in a pressure range of 1-101 bar oxygen, and temperature of 140 °C. Under such conditions, diffusion limited current densities increase by almost two orders of magnitude as compared to conventional RDE setups allowing, for example, fuel cell catalyst studies under more realistic conditions. Levich plots demonstrate that the mass transport is indeed well-defined, i.e., at low electrode potentials, the measured current densities are fully diffusion controlled, while at higher potentials, a mixed kinetic-diffusion controlled regime is observed. Therefore, the setup opens up a new field for RDE investigations under temperature and current density conditions relevant for low and high temperature proton exchange membrane fuel cells.

  3. Creep of Posidonia Shale at Elevated Pressure and Temperature

    Science.gov (United States)

    Rybacki, E.; Herrmann, J.; Wirth, R.; Dresen, G.

    2017-12-01

    The economic production of gas and oil from shales requires repeated hydraulic fracturing operations to stimulate these tight reservoir rocks. Besides simple depletion, the often observed decay of production rate with time may arise from creep-induced fracture closure. We examined experimentally the creep behavior of an immature carbonate-rich Posidonia shale, subjected to constant stress conditions at temperatures between 50 and 200 °C and confining pressures of 50-200 MPa, simulating elevated in situ depth conditions. Samples showed transient creep in the semibrittle regime with high deformation rates at high differential stress, high temperature and low confinement. Strain was mainly accommodated by deformation of the weak organic matter and phyllosilicates and by pore space reduction. The primary decelerating creep phase observed at relatively low stress can be described by an empirical power law relation between strain and time, where the fitted parameters vary with temperature, pressure and stress. Our results suggest that healing of hydraulic fractures at low stresses by creep-induced proppant embedment is unlikely within a creep period of several years. At higher differential stress, as may be expected in situ at contact areas due to stress concentrations, the shale showed secondary creep, followed by tertiary creep until failure. In this regime, microcrack propagation and coalescence may be assisted by stress corrosion. Secondary creep rates were also described by a power law, predicting faster fracture closure rates than for primary creep, likely contributing to production rate decline. Comparison of our data with published primary creep data on other shales suggests that the long-term creep behavior of shales can be correlated with their brittleness estimated from composition. Low creep strain is supported by a high fraction of strong minerals that can build up a load-bearing framework.

  4. Dust acoustic waves in complex plasmas at elevated pressure

    International Nuclear Information System (INIS)

    Filippov, A.V.; Starostin, A.N.; Tkachenko, I.M.; Fortov, V.E.

    2011-01-01

    The bi-Yukawa effective interaction potential with different screening constants is employed to calculate dust static correlation functions in the hyper-netted chain approximation and to generalize the theory of dust acoustic waves within the non-perturbative moment approach complemented by hydrodynamic considerations. For the bi-Yukawa interaction potential the sound speed becomes significantly wavenumber-dependent, an additional soft diffusion-like mode is predicted, and the static dielectric function is shown to take negative values. The results can be applied to non-equilibrium dusty plasmas at elevated pressure. -- Highlights: ► Bi-Yukawa interaction potential of dust particles with different screening lengths. ► Dust static correlation functions in the hyper-netted chain approximation. ► The moment and hydrodynamic approaches are in a good agreement at weak non-ideality. ► The dust acoustic wave phase and group velocities depend on the wavenumber. ► The moment approach hints the appearance of the diffusion-like soft mode.

  5. Congeneration feasibility: Otis Elevator Company and Polychrome Corporation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fox, H.

    1982-05-01

    This report summarizes an investigation of the technical and economic feasibility of cogenerating electric and thermal power at two manufacturing plants (Otis Elevator Company and Polychrome Corporation) located on neighboring properties in Yonkers, NY. Existing electrical- and steam-producing equipment and energy consumption date are summarized. Alternative cases examined include electrical energy generation, electrical energy generation with waste heat recovery and a combined cycle case. Also reported are life cycle cost economic evaluations including simple payback period and return-on-investment indices. While it was concluded that cogeneration of heat and electricity at these industrial plant sites would not be economically viable, this detailed study provides valuable insight into the types of problems encountered when considering cogeneration feasibility.

  6. Cogeneration feasibility: Otis Elevator Company and Polychrome Corporation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-01

    The purpose of this study was to assess the feasibility of cogeneration at Otis Elevator Company and Polychrome Corporation located in Westchester County, New York. Each plant and its associated thermal and electrical load is reviewed. Three basic cycles for the cogeneration are investigated: power only, power generation with waste heat recovery, and combined cycle. Each case was assessed economically, beginning with a screening method to suggest those configurations most likely to be implemented and continuing through an assessment of the regulatory environment for cogeneration and an analysis of rate structures for buy back power, displaced power, and supplementing service. It is concluded that: for a plant designed to supply the combined loads of the two corporations, interconnection costs coupled to the coincidence of load result in unfavorable economics; for separate cogeneration plants, owned and operated by each individual corporation, energy consumption patterns and the current regulatory environment, in particular the existing and proposed cogeneration system rate structures, do not permit viable economics for the proposed plants; but if the proposed cycle were owned and operated by a new entity (neither Otis/Polychrome nor the utility), an economic scheme with marginal financial benefits can be developed and may be worthy of further study. (LEW)

  7. Investigating Soot Morphology in Counterflow Flames at Elevated Pressures

    KAUST Repository

    Amin, Hafiz Muhammad Fahid

    2018-01-01

    Practical combustion devices such as gas turbines and diesel engines operate at high pressures to increase their efficiency. Pressure significantly increases the overall soot yield. Morphology of these ultra-fine particles determines their airborne

  8. Breakdown pressures and characteristic flaw sizes during fluid injection experiments in shale at elevated confining pressures.

    Science.gov (United States)

    Chandler, M.; Mecklenburgh, J.; Rutter, E. H.; Taylor, R.; Fauchille, A. L.; Ma, L.; Lee, P. D.

    2017-12-01

    Fracture propagation trajectories in gas-bearing shales depend on the interaction between the anisotropic mechanical properties of the shale and the anisotropic in-situ stress field. However, there is a general paucity of available experimental data on their anisotropic mechanical, physical and fluid-flow properties, especially at elevated confining pressures. A suite of mechanical, flow and elastic measurements have been made on two shale materials, the Whitby mudrock and the Mancos shale (an interbedded silt and mudstone), as well as Pennant sandstone, an isotropic baseline and tight-gas sandstone analogue. Mechanical characterization includes standard triaxial experiments, pressure-dependent permeability, brazilian disk tensile strength, and fracture toughness determined using double-torsion experiments. Elastic characterisation was performed through ultrasonic velocities determined using a cross-correlation method. Additionally, we report the results of laboratory-scale fluid injection experiments for the same materials. Injection experiments involved the pressurisation of a blind-ending central hole in a dry cylindrical sample. Pressurisation is conducted under constant volume-rate control, using silicon oils of varying viscosities. Breakdown pressure is not seen to exhibit a strong dependence on rock type or orientation, and increases linearly with confining pressure. In most experiments, a small drop in the injection pressure record is observed at what is taken to be fracture initiation, and in the Pennant sandstone this is accompanied by a small burst of acoustic energy. The shale materials were acoustically quiet. Breakdown is found to be rapid and uncontrollable after initiation if injection is continued. A simplified 2-dimensional model for explaining this is presented in terms of the stress intensities at the tip of a pressurised crack, and is used alongside the triaxial data to derive a characteristic flaw size from which the fractures have initiated

  9. Investigations of Sooting Laminar Coflow Diffusion Flames at Elevated Pressures

    KAUST Repository

    Steinmetz, Scott

    2016-01-01

    diameters are successfully measured in nitrogen-diluted ethylene-air laminar coflow flames at pressures of 4, 8, 12, and 16 atm. An increase in particle size with pressure is found up to 12 atm, where particle sizes plateau. Particle size in the annulus

  10. A pitfall in the measurement of arterial blood pressure in the ischaemic limb during elevation

    DEFF Research Database (Denmark)

    Bülow, J; Jelnes, Rolf

    1987-01-01

    In order to evaluate if elevation of the ischaemic limb above heart level is an alternative to the conventionally applied method with external counterpressure for estimation of skin perfusion pressure, femoral and popliteal artery pressures were measured directly in eight patients with occlusion...... of the superficial femoral artery. The measurements were done in the horizontal position and during elevation of the calf above heart level. During elevation relative blood flow, measured by arterio-venous oxygen saturation differences, decreased compared with the horizontal position. In contrast the popliteal...... arterial pressure decreased only by 20% of the value expected from the degree of elevation of the calf above the level of the heart. Thus, it could be calculated that calf vascular resistance increased two- to three-fold on average during elevation. Four patients were reexamined with the venous pressure...

  11. The conundrum of arterial stiffness, elevated blood pressure, and aging.

    Science.gov (United States)

    AlGhatrif, Majd; Lakatta, Edward G

    2015-02-01

    Isolated systolic hypertension is a major health burden that is expanding with the aging of our population. There is evidence that central arterial stiffness contributes to the rise in systolic blood pressure (SBP); at the same time, central arterial stiffening is accelerated in patients with increased SBP. This bidirectional relationship created a controversy in the field on whether arterial stiffness leads to hypertension or vice versa. Given the profound interdependency of arterial stiffness and blood pressure, this question seems intrinsically challenging, or probably naïve. The aorta's function of dampening the pulsatile flow generated by the left ventricle is optimal within a physiological range of distending pressure that secures the required distal flow, keeps the aorta in an optimal mechanical conformation, and minimizes cardiac work. This homeostasis is disturbed by age-associated, minute alterations in aortic hemodynamic and mechanical properties that induce short- and long-term alterations in each other. Hence, it is impossible to detect an "initial insult" at an epidemiological level. Earlier manifestations of these alterations are observed in young adulthood with a sharp decline in aortic strain and distensibility accompanied by an increase in diastolic blood pressure. Subsequently, aortic mechanical reserve is exhausted, and aortic remodeling with wall stiffening and dilatation ensue. These two phenomena affect pulse pressure in opposite directions and different magnitudes. With early remodeling, there is an increase in pulse pressure, due to the dominance of arterial wall stiffness, which in turn accelerates aortic wall stiffness and dilation. With advanced remodeling, which appears to be greater in men, the effect of diameter becomes more pronounced and partially offsets the effect of wall stiffness leading to plateauing in pulse pressure in men and slower increase in pulse pressure (PP) than that of wall stiffness in women. The complex nature of

  12. Macroglia-derived thrombospondin 2 regulates alterations of presynaptic proteins of retinal neurons following elevated hydrostatic pressure.

    Science.gov (United States)

    Wang, Shuchao; Hu, Tu; Wang, Zhen; Li, Na; Zhou, Lihong; Liao, Lvshuang; Wang, Mi; Liao, Libin; Wang, Hui; Zeng, Leping; Fan, Chunling; Zhou, Hongkang; Xiong, Kun; Huang, Jufang; Chen, Dan

    2017-01-01

    protein upregulated the level of presynaptic proteins. Finally, gabapentin decreased the expression of presynaptic proteins in mixed cultures by blocking the interaction of thrombospondin 2 and α2δ-1. Taken together, these results indicate that activated macroglia cells may participate in alterations of presynaptic proteins of retinal neurons following elevated hydrostatic pressure, and macroglia-derived thrombospondin 2 may modulate these changes via binding to its neuronal receptor α2δ-1.

  13. Involvement of Smad3 pathway in atrial fibrosis induced by elevated hydrostatic pressure.

    Science.gov (United States)

    Wei, Wei; Rao, Fang; Liu, Fangzhou; Xue, Yumei; Deng, Chunyu; Wang, Zhaoyu; Zhu, Jiening; Yang, Hui; Li, Xin; Zhang, Mengzhen; Fu, Yongheng; Zhu, Wensi; Shan, Zhixin; Wu, Shulin

    2018-06-01

    Hypertension is a main risk factor for atrial fibrillation, but the direct effects of hydrostatic pressure on the atrial fibrosis are still unknown. The present study investigated whether hydrostatic pressure is responsible for atrial fibrosis, and addressed a potential role of the Smad pathway in this pathology. Biochemical assays were used to study regulation and expression of fibrotic factors in spontaneously hypertensive rats (SHRs) and Wistar rats, and in cardiac fibroblasts (CFs) cultured under standard (0 mmHg) and elevated (20, 40 mmHg) hydrostatic pressure. Levels of atrial fibrosis and protein expression of fibrotic factors Col-1A1/-3A1, TGF-β1, and MMP-2 in SHRs' left atrial tissues were higher than those in Wistar rats. Exposure to elevated pressure was associated with the proliferation of CFs. The protein expression of Col-1A1/-3A1, TGF-β1, and MMP-2 in CFs was also up-regulated in a pressure-dependent manner. The proliferation of CFs and increased expressions of fibrotic markers induced by elevated hydrostatic pressure could be reversed by the Smad3 inhibitor naringenin. The activation of Smad3 pathway was also stimulated by elevated hydrostatic pressure. These results demonstrate that CF secretory function and proliferation can be up-regulated by exposure to elevated pressure, and that Smad3 may modulate CF activation induced by high hydrostatic pressure. © 2017 Wiley Periodicals, Inc.

  14. Laser ignition of liquid petroleum gas at elevated pressures

    Science.gov (United States)

    Loktionov, E.; Pasechnikov, N.; Telekh, V.

    2017-11-01

    Recent development of laser spark plugs for internal combustion engines have shown lack of data on laser ignition of fuel mixtures at multi-bar pressures needed for laser pulse energy and focusing optimisation. Methane and hydrogen based mixtures are comparatively well investigated, but propane and butane based ones (LPG), which are widely used in vehicles, are still almost unstudied. Optical breakdown thresholds in gases decrease with pressure increase up to ca. 100 bar, but breakdown is not a sufficient condition for combustion ignition. So minimum ignition energy (MIE) becomes more important for combustion core onset, and its dependency on mixture composition and pressure has several important features. For example, unlike breakdown threshold, is poorly dependent on laser pulse length, at least in pico- and to microsecond range. We have defined experimentally the dependencies of minimum picosecond laser pulse energies (MIE related value) needed for ignition of LPG based mixtures of 1.0 to 1.6 equivalence ratios and pressure of 1.0 to 3.5 bar. In addition to expected values decrease, low-energy flammability range broadening has been found at pressure increase. Laser ignition of LPG in Wankel rotary engine is reported for the first time.

  15. Comparative Autoignition Trends in Butanol Isomers at Elevated Pressure

    KAUST Repository

    Weber, Bryan W.

    2013-03-21

    Autoignition experiments of stoichiometric mixtures of s-, t-, and i-butanol in air have been performed using a heated rapid compression machine (RCM). At compressed pressures of 15 and 30 bar and for compressed temperatures in the range 715-910 K, no evidence of a negative temperature coefficient region in terms of ignition delay response is found. The present experimental results are also compared with previously reported RCM data of n-butanol in air. The order of reactivity of the butanols is n-butanol > s-butanol ≈ i-butanol > t-butanol at the lower pressure but changes to n-butanol > t-butanol > s-butanol > i-butanol at higher pressure. In addition, t-butanol shows preignition heat release behavior, which is especially evident at higher pressures. To help identify the controlling chemistry leading to this preignition heat release, off-stoichiometric experiments are further performed at 30 bar compressed pressure, for t-butanol at φ = 0.5 and φ = 2.0 in air. For these experiments, higher fuel loading (i.e., φ = 2.0) causes greater preignition heat release (as indicated by greater pressure rise) than the stoichiometric or φ = 0.5 cases. Comparison of the experimental ignition delays with the simulated results using two literature kinetic mechanisms shows generally good agreement, and one mechanism is further used to explore and compare the fuel decomposition pathways of butanol isomers. Using this mechanism, the importance of peroxy chemistry in the autoignition of the butanol isomers is highlighted and discussed. © 2013 American Chemical Society.

  16. Prevalence of obesity and elevated blood pressure among bankers ...

    African Journals Online (AJOL)

    The aim of this study was to determine the prevalence of obesity and hypertension among bankers in Lagos State, Nigeria. Methods: Blood pressure, body mass index (BMI) and waist circumference were measured in 260 professional bankers from 56 bank branches in Lagos. Results: The mean age of the respondents was ...

  17. Measurements and modeling of VLLE at elevated pressures

    DEFF Research Database (Denmark)

    Laursen, Torben

    and pure component calibration. Samples from the different liquid phases in the high-pressure cell is taken using a moveable needle. The systems investigated have been a combination of the components: CO2, N2, di-methyl ether (DME), water, methanol, ethanol and 1-propanol. 41 isotherms have been measured...

  18. Elevated blood pressure among primary school children in Dar es salaam, Tanzania: prevalence and risk factors.

    Science.gov (United States)

    Muhihi, Alfa J; Njelekela, Marina A; Mpembeni, Rose N M; Muhihi, Bikolimana G; Anaeli, Amani; Chillo, Omary; Kubhoja, Sulende; Lujani, Benjamin; Maghembe, Mwanamkuu; Ngarashi, Davis

    2018-02-13

    Whilst the burden of non-communicable diseases is increasing in developing countries, little data is available on blood pressure among Tanzanian children. This study aimed at determining the blood pressure profiles and risk factors associated with elevated blood pressure among primary school children in Dar es Salaam, Tanzania. We conducted a cross sectional survey among 446 children aged 6-17 years from 9 randomly selected primary schools in Dar es Salaam. We measured blood pressure using a standardized digital blood pressure measuring machine (Omron Digital HEM-907, Tokyo, Japan). We used an average of the three blood pressure readings for analysis. Elevated blood pressure was defined as average systolic or diastolic blood pressure ≥ 90th percentile for age, gender and height. The proportion of children with elevated blood pressure was 15.2% (pre-hypertension 4.4% and hypertension 10.8%). No significant gender differences were observed in the prevalence of elevated BP. Increasing age and overweight/obese children were significantly associated with elevated BP (p = 0.0029 and p < 0.0001) respectively. Similar associations were observed for age and overweight/obesity with hypertension. (p = 0.0506 and p < 0.0001) respectively. In multivariate analysis, age above 10 years (adjusted RR = 3.63, 95% CI = 1.03-7.82) was significantly and independently associated with elevated BP in this population of school age children. We observed a higher proportion of elevated BP in this population of school age children. Older age and overweight/obesity were associated with elevated BP. Assessment of BP and BMI should be incorporated in school health program in Tanzania to identify those at risk so that appropriate interventions can be instituted before development of associated complications.

  19. Measurement of local void fraction at elevated temperature and pressure

    International Nuclear Information System (INIS)

    Duncan, D.; Trabold, T.A.

    1993-03-01

    Significant advances have recently been made in analytical and computational methods for the prediction of local thermal-hydraulic conditions in gas/liquid two-phase flows. There is, however, a need for extensive experimental data, for the dual purposes of constitutive relation development and code qualification. There is especially true of systems involving complicated geometries and/or extreme flow conditions for which little, if any, applicable information exists in the open literature. For the tests described in the present paper, a novel electrical probe has been applied to measure the void fraction in atmospheric pressure air/water flows, and steam/water mixtures at high temperature and pressure. The data acquired in the latter experiments are compared with the results of a one-dimensional two-fluid computational analysis

  20. Hydrodynamics in a cocurrent gas-liquid trickle bed at elevated pressures

    NARCIS (Netherlands)

    Wammes, W.J.A.; Middelkamp, J.; Huisman, W.J.; Huisman, W.J.; de Baas, C.M.; de Baas, C.M.; Westerterp, K.R.

    1991-01-01

    Data on design and operation of trickle beds at elevated pressures are scarce. In this study the influence of the gas density on the liquid holdup, the pressure drop, and the transition between trickle and pulse flow has been investigated in a tricklebed reactor operating up to 7.5 MPa and with

  1. Using Smartphone Pressure Sensors to Measure Vertical Velocities of Elevators, Stairways, and Drones

    Science.gov (United States)

    Monteiro, Martín; Martí, Arturo C.

    2017-01-01

    We measure the vertical velocities of elevators, pedestrians climbing stairs, and drones (flying unmanned aerial vehicles), by means of smartphone pressure sensors. The barometric pressure obtained with the smartphone is related to the altitude of the device via the hydrostatic approximation. From the altitude values, vertical velocities are…

  2. Elevated temperature and high pressure large helium gas loop

    International Nuclear Information System (INIS)

    Sakasai, Minoru; Midoriyama, Shigeru; Miyata, Toyohiko; Nakase, Tsuyoshi; Izaki, Makoto

    1979-01-01

    The development of high temperature gas-cooled reactors especially aiming at the multi-purpose utilization of nuclear heat energy is carried out actively in Japan and West Germany. In Japan, the experimental HTGR of 50 MWt and 1000 deg C outlet temperature is being developed by Japan Atomic Energy Research Institute and others since 1969, and the development of direct iron-making technology utilizing high temperature reducing gas was started in 1973 as the large project of Ministry of Internalional Trade and Industry. Kawasaki Heavy Industries, Ltd., Has taken part in these development projects, and has developed many softwares for nuclear heat design, system design and safety design of nuclear reactor system and heat utilization system. In hardwares also, efforts have been exerted to develop the technologies of design and manufacture of high temperature machinery and equipments. The high temperature, high pressure, large helium gas loop is under construction in the technical research institute of the company, and it is expected to be completed in December, 1979. The tests planned are that of proving the dynamic performances of the loop and its machinery and equipments and the verification of analysis codes. The loop is composed of the main circulation system, the objects of testing, the helium gas purifying system, the helium supplying and evacuating system, instruments and others. (Kako, I.)

  3. Solubility of krypton in hydrofracture grout at elevated pressures

    International Nuclear Information System (INIS)

    Fitzgerald, C.L.; Mailen, J.C.

    1982-01-01

    The solubilities of krypton in water, simulated waste solution, and simulated grout at about 25 0 C and to pressures of 150 atm have been determined. The results of these studies show that preliminary calculations of krypton solubility based on the aqueous component of the hydrofracture grout were overly pessimistic. The volume of noble gas generated annually by the reference reprocessing plant would be soluble in the annual hydrofracture grout injection at ORNL at about 10 atm. The amount of krypton in the gas phase would depend on the amount of air in the hydrofracture grout mixture. At 34 atm, and with a small air volume relative to the injected krypton, the krypton would constitute about 30% of the gas bubbles. The disposal of krypton via injection with hydrofracture grout seems to be a viable process. The next logical steps would be to determine the krypton diffusion rate at injection conditions, and possibly to perform a test injection. At present, the schedule for future work is uncertain since funds for this project have been reduced significantly

  4. Selective loss of orientation column maps in visual cortex during brief elevation of intraocular pressure.

    Science.gov (United States)

    Chen, Xin; Sun, Chao; Huang, Luoxiu; Shou, Tiande

    2003-01-01

    To compare the orientation column maps elicited by different spatial frequency gratings in cortical area 17 of cats before and during brief elevation of intraocular pressure (IOP). IOP was elevated by injecting saline into the anterior chamber of a cat's eye through a syringe needle. The IOP was elevated enough to cause a retinal perfusion pressure (arterial pressure minus IOP) of approximately 30 mm Hg during a brief elevation of IOP. The visual stimulus gratings were varied in spatial frequency, whereas other parameters were kept constant. The orientation column maps of the cortical area 17 were monocularly elicited by drifting gratings of different spatial frequencies and revealed by a brain intrinsic signal optical imaging system. These maps were compared before and during short-term elevation of IOP. The response amplitude of the orientation maps in area 17 decreased during a brief elevation of IOP. This decrease was dependent on the retinal perfusion pressure but not on the absolute IOP. The location of the most visible maps was spatial-frequency dependent. The blurring or loss of the pattern of the orientation maps was most severe when high-spatial-frequency gratings were used and appeared most significantly on the posterior part of the exposed cortex while IOP was elevated. However, the basic patterns of the maps remained unchanged. Changes in cortical signal were not due to changes in the optics of the eye with elevation of IOP. A stable normal IOP is essential for maintaining normal visual cortical functions. During a brief and high elevation of IOP, the cortical processing of high-spatial-frequency visual information was diminished because of a selectively functional decline of the retinogeniculocortical X pathway by a mechanism of retinal circulation origin.

  5. Analysis and evaluation system for elevated temperature design of pressure vessels

    International Nuclear Information System (INIS)

    Hayakawa, Teiji; Sayawaki, Masaaki; Nishitani, Masahiro; Mii, Tatsuo; Murasawa, Kanji

    1977-01-01

    In pressure vessel technology, intensive efforts have recently been made to develop the elevated temperature design methods. Much of the impetus of these efforts has been provided mainly by the results of the Liquid Metal Fast Breeder Reactor (LMFBR) and more recently, of the High Temperature Gas-cooled Reactor (HTGR) Programs. The pressure vessels and associated components in these new type nuclear power plants must operate for long periods at elevated temperature where creep effects are significant and then must be designed by rigorous analysis for high reliability and safety. To carry out such an elevated temperature designing, numbers of highly developed analysis and evaluation techniques, which are so complicated as to be impossible by manual work, are indispensable. Under these circumstances, the authors have made the following approaches in the study: (1) Study into basic concepts and the associated techniques in elevated temperature design. (2) Systematization (Analysis System) of the procedure for loads and stress analyses. (3) Development of post-processor, ''POST-1592'', for strength evaluation based on ASME Code Case 1592-7. By linking the POST-1592 together with the Analysis System, an analysis and evaluation system is developed for an elevated temperature design of pressure vessels. Consequently, designing of elevated temperature vessels by detailed analysis and evaluation has easily and effectively become feasible by applying this software system. (auth.)

  6. The difference in endolymphatic hydrostatic pressure elevation induced by isoproterenol between the ampulla and the cochlea.

    Science.gov (United States)

    Inamoto, Ryuhei; Miyashita, Takenori; Matsubara, Ai; Hoshikawa, Hiroshi; Mori, Nozomu

    2017-06-01

    The purpose of the study was to investigate the difference in the responses of endolymphatic hydrostatic pressure to isoproterenol, β-adrenergic receptor agonist, between pars superior and pars inferior. The hydrostatic pressure of endolymph and perilymph and endolymphatic potential in the ampulla and the cochlea during the intravenous administration of isoproterenol were recorded using a servo-null system in guinea pigs. The hydrostatic pressure of endolymph and perilymph in the ampulla and cochlea was similar in magnitude. Isoproterenol significantly increased hydrostatic pressure of ampullar and cochlear endolymph and perilymph with no change in the ampullar endolymphatic potential and endocochlear potential, respectively. The isoproterenol-induced maximum change of endolymphatic hydrostatic pressure in ampulla was significantly (phydrostatic pressure in the ampulla disappeared like that in the cochlea. Isoproterenol elevates endolymphatic hydrostatic pressure in different manner between the vestibule and the cochlea. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Traffic congestion and blood pressure elevation: A comparative cross-sectional study in Lebanon.

    Science.gov (United States)

    Bou Samra, Patrick; El Tomb, Paul; Hosni, Mohammad; Kassem, Ahmad; Rizk, Robin; Shayya, Sami; Assaad, Sarah

    2017-12-01

    This comparative cross-sectional study examines the association between traffic congestion and elevation of systolic and/or diastolic blood pressure levels among a convenience sample of 310 drivers. Data collection took place during a gas station pause at a fixed time of day. Higher average systolic (142 vs 123 mm Hg) and diastolic (87 vs 78 mm Hg) blood pressures were detected among drivers exposed to traffic congestion compared with those who were not exposed (P<.001), while controlling for body mass index, age, sex, pack-year smoking, driving hours per week, and occupational driving. Moreover, among persons exposed to traffic congestion, longer exposure time was associated with higher systolic and diastolic blood pressures. Further studies are needed to better understand the mechanisms of the significant association between elevated blood pressure and traffic congestion. ©2017 Wiley Periodicals, Inc.

  8. Serum Endoglin Levels in Patients Suffering from Systemic Sclerosis and Elevated Systolic Pulmonary Arterial Pressure

    Directory of Open Access Journals (Sweden)

    Paola Ximena Coral-Alvarado

    2010-01-01

    Full Text Available Background. Pulmonary arterial hypertension (PAH is the main cause of morbimortality in systemic sclerosis (SSc. Increased Eng expression has been demonstrated in SSc patients. Objective. Ascertaining serum levels of Eng in SSc patients with and without elevated systolic pulmonary arterial pressure (sPAP and comparing them with that of healthy volunteers. Methods. A cross-sectional study was carried out. A commercial ELISA kit was used for measuring serum concentrations of Eng in 60 subjects: 40 patients with SSc with and without elevated sPAP, compared to 20 healthy control subjects. Elevated sPAP was detected by echocardiogram. Results. No association between positive Eng and elevated sPAP was found when compared to the SSc without elevated sPAP group (OR=2.85; 0.65–12.88 95% CI; P=.11; however, an association was found between positive Eng and elevated sPAP compared to healthy controls (OR=23.22; 2.46–1050.33 95% CI; P=.001, and weak association was found between the positive Eng with SSc without elevated sPAP group compared to healthy controls (OR=8.14, 0.8–393.74 95% CI; P=.046. Conclusion. Raised serum levels of Eng in SSc patients compared to healthy controls were found, suggesting a role for Eng in SSc vasculopathy and not just in elevated sPAP. However, prospective studies are needed to verify such observations.

  9. Experimental and modelling study of the effect of elevated pressure on ethane and propane flames

    NARCIS (Netherlands)

    Goswami, M.; Bastiaans, R.J.M.; de Goey, L.P.H.; Konnov, A.A.

    2016-01-01

    Laminar burning velocities, SL, of ethane + air and propane + air flames within an equivalence ratio range between 0.8 and 1.3 were determined at atmospheric and elevated pressures up to 4 atm. Measurements were performed in non-stretched flames, stabilized on a perforated plate burner at adiabatic

  10. Acetone photophysics at 282 nm excitation at elevated pressure and temperature. II: Fluorescence modeling

    Science.gov (United States)

    Hartwig, Jason; Raju, Mandhapati; Sung, Chih-Jen

    2017-07-01

    This is the second in a series of two papers that presents an updated fluorescence model and compares with the new experimental data reported in the first paper, as well as the available literature data, to extend the range of acetone photophysics to elevated pressure and temperature conditions. This work elucidates the complete acetone photophysical model in terms of each and every competing radiative and non-radiative rate. The acetone fluorescence model is then thoroughly examined and optimized based on disparity with recently conducted elevated pressure and temperature photophysical calibration experiments. The current work offers insight into the competition between non-radiative and vibrational energy decay rates at elevated temperature and pressure and proposes a global optimization of model parameters from the photophysical model developed by Thurber (Acetone Laser-Induced Fluorescence for Temperature and Multiparameter Imaging in Gaseous Flows. PhD thesis, Stanford University Mechanical Engineering Department, 1999). The collisional constants of proportionality, which govern vibrational relaxation, are shown to be temperature dependent at elevated pressures. A new oxygen quenching rate is proposed which takes into account collisions with oxygen as well as the oxygen-assisted intersystem crossing component. Additionally, global trends in ketone photophysics are presented and discussed.

  11. Time-Resolved WAXD and SAXS Investigations on Butyl Branched Alkane at Elevated Pressures

    NARCIS (Netherlands)

    Rastogi, A.; Hobbs, J.K.; Rastogi, S.

    2002-01-01

    The crystallization behavior and the morphological aspect of the butyl branched alkane C96H193CH(C4H9)C94H189 have been investigated using time-resolved wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) at atmospheric and elevated pressures. The solution crystallized sample

  12. Phenylephrine-induced elevations in arterial blood pressure are attenuated in heat-stressed humans

    Science.gov (United States)

    Cui, Jian; Wilson, Thad E.; Crandall, Craig G.

    2002-01-01

    To test the hypothesis that phenylephrine-induced elevations in blood pressure are attenuated in heat-stressed humans, blood pressure was elevated via steady-state infusion of three doses of phenylephrine HCl in 10 healthy subjects in both normothermic and heat stress conditions. Whole body heating significantly increased sublingual temperature by 0.5 degrees C, muscle sympathetic nerve activity (MSNA), heart rate, and cardiac output and decreased total peripheral vascular resistance (TPR; all P blood pressure (MAP; P > 0.05). At the highest dose of phenylephrine, the increase in MAP and TPR from predrug baselines was significantly attenuated during the heat stress [DeltaMAP 8.4 +/- 1.2 mmHg; DeltaTPR 0.96 +/- 0.85 peripheral resistance units (PRU)] compared with normothermia (DeltaMAP 15.4 +/- 1.4 mmHg, DeltaTPR 7.13 +/- 1.18 PRU; all P blood pressure, as well as the slope of the relationship between heart rate and systolic blood pressure, respectively, was similar between thermal conditions (each P > 0.05). These data suggest that phenylephrine-induced elevations in MAP are attenuated in heat-stressed humans without affecting baroreflex control of MSNA or heart rate.

  13. Study on Combustion Oscillation of Premixed Flame with Pilot Fuel at Elevated Pressures

    Science.gov (United States)

    Ohtsuka, Masaya; Yoshida, Shohei; Hirata, Yoshitaka; Kobayashi, Nariyoshi

    Acoustically-coupled combustion oscillation is studied for premixed flame with pilot fuel to be used in gas turbine combustors. Premixed gas is passed through swirl vanes and burnt with the centrally injected pilot fuel. The dependencies of pressure, fuel to air ratio, premixed fuel rate, inlet velocity and air temperature on the combustion oscillation are investigated. Two kinds of oscillation modes of ˜100Hz and ˜350Hz are activated according to inlet velocities. Fluctuating pressures are amplified when the premixed fuel rate is over ˜80% at elevated pressures. The fluctuating pressure peak moves to a higher premixed fuel ratio region with increased pressure or fuel to air ratio for the Helmholz type mode. Combustion oscillation occurs when the pilot fuel velocity is changed proportionally with the flame length.

  14. Frequency of diarrhoea as a predictor of elevated blood pressure in children

    Science.gov (United States)

    Miranda, Juan Jaime; Davies, Alisha R.; Smith, George Davey; Smeeth, Liam; Cabrera, Lilia; Gilman, Robert H.; García, Héctor H.; Ortega, Ynes R.; Cama, Vitaliano A.

    2009-01-01

    Background Diarrhoeal illness is a major public health problem for children worldwide, particularly among developing countries, and is a proxy condition for severe dehydration. It has been hypothesized that severe dehydration in the first 6 months of life could be associated with increased blood pressure later in life. This study aimed to explore whether frequency of diarrhoea is associated with elevated blood pressure in children in a setting with a high incidence of diarrhoeal disease. Methods The present study is a cross-sectional study of blood pressure among children from a longitudinal child diarrhoeal disease cohort in Lima, Peru. From 2001 to 2006, daily diarrhoeal surveillance was made. Children were revisited in 2006 and blood pressure was measured. Diarrhoeal exposures were evaluated in terms of total number of diarrhoea days, number of episodes of diarrhoea, persistent diarrhoeal episodes and by the quartiles of daily incidence and episode incidence of diarrhoea. Results The overall incidence of diarrhoeal episodes at age under 1 year was 4.35 (95% confidence interval: 3.79-4.98) and under 5 years was 2.80 (95% confidence interval: 2.69-2.92). No association was observed between the total number of diarrhoeal days, diarrhoeal episodes or diarrhoeal incidence rates with childhood blood pressure. There was weak evidence that hospital admission due to severe dehydration in the first year of life showed a gradient towards an increase in both, systolic and diastolic blood pressure. Conclusion In the first study to date to examine the association in a setting with a high incidence of diarrhoeal disease, diarrhoeal frequency did not show an association with increased blood pressure. Our observations of elevated levels of blood pressure among those admitted into hospitals in the first year of life are in line with the original hypothesis of dehydration in early infancy and high blood pressure. However, the effect of episodes of severe dehydration on later blood

  15. The relationship between elevated interstitial fluid pressure and blood flow in tumors: a bioengineering analysis

    International Nuclear Information System (INIS)

    Milosevic, Michael F.; Fyles, Anthony W.; Hill, Richard P.

    1999-01-01

    Purpose: To examine the hypothesis that elevated interstitial fluid pressure (IFP) is a cause of reduced blood flow in tumors. Materials and Methods: A physiologic model of tumor blood flow was developed based on a semipermeable, compliant capillary in the center of a spherical tumor. The model incorporates the interaction between the tumor vasculature and the interstitium, as mediated by IFP. It also incorporates the dynamic behavior of the capillary wall in response to changes in transmural pressure, and the effect of viscosity on blood flow. Results: The model predicted elevated tumor IFP in the range of 0 to 56 mmHg. The capillary diameter in the setting of elevated IFP was greatest at the arterial end, and constricted to between 3.2 and 4.4 μm at the venous end. This corresponded to a 2.4- to 3.5-fold reduction in diameter along the length of the capillary. The IFP exceeded the intravascular pressure distally in the capillary, but vascular collapse did not occur. Capillary diameter constriction resulted in a 2.3- to 9.1-fold steady-state reduction in tumor blood flow relative to a state of near-zero IFP. Conclusion: The results suggest that steady-state vascular constriction occurs in the setting of elevated IFP, and leads to reduced tumor blood flow. This may in turn contribute to the development of hypoxia, which is an important cause of radiation treatment failure in many tumors

  16. Evaulation of Incidence and Risk Factors for Intraocular Pressure Elevation After Intravitreal Triamcinolone Acetonide Injection

    Directory of Open Access Journals (Sweden)

    Didar Uçar

    2015-05-01

    Full Text Available Objectives: To investigate the effect of intravitreal triamcinolone acetonide (IVTA used for the macular edema on intraocular pressure (IOP and to determine the risk factors for IOP elevation. Materials and Methods: This retrospective study included 93 eyes of 85 patients who had 4 mg intravitreal triamcinolone injection. Of the 85 patients, 56 (65.8% had diabetic macular edema, 22 (25.8% had branch retinal, and 7 (8.2% had central retinal vein occlusion. IOP changes after injection as well as the relation between IOP elevation and age, sex, lens status, etiology of macular edema, baseline IOP were evaluated. Results: Fourty-six male and 39 female patients with mean age 61.58±9.5 years were evaluated. IOP was recorded to be >24 mmHg in 30 eyes (32.2% at follow-up visit after an average of 7.5 weeks. Normalization of IOP with medication was achieved in all IOP elevated eyes. Fifteen of 29 eyes (51.7% with vein occlusion and 15 of 64 eyes (23.3% with diabetic macula edema had IOP elevation (p=0.01. Twenty-six of 73 phakic (35.6% and 4 of 20 pseudophakic eyes (20% had IOP >24 mmHg (p=0.16. There was no association between IOP elevation and sex (p=0.33. Baseline IOP was 16.47±2.8 mmHg in eyes which had elevated IOP and 14.78±2.4 mmHg in the remaining. There was significant relation between IOP elevation and baseline IOP level (p=0.01. Conclusion: Elevated IOP is common side effect after IVTA, but normalization is usually achieved by topical medication. Patients with baseline IOP ≥15 mmHg and vein occlusion have higher risk for IOP elevation. (Turk J Ophthalmol 2015; 45: 86-91

  17. Desirability of oysters treated by high pressure processing at different temperatures and elevated pressures

    Science.gov (United States)

    Organoleptic changes in sterile triploid oysters (Crassostrea virginica) induced by high pressure processing (HPP) were investigated using a volunteer panel. Using a 1-7 hedonic scale, where seven is “like very much”, and one is “dislike very much”, oysters were evaluated organoleptically for flavo...

  18. Associations between adiposity indicators and elevated blood pressure among Chinese children and adolescents.

    Science.gov (United States)

    Dong, B; Wang, Z; Wang, H-J; Ma, J

    2015-04-01

    Adiposity is closely related to elevated blood pressure (BP); however, which adiposity indicator is the best predictor of elevated BP among children and adolescents is unclear. To clarify this, 99,366 participants aged 7-17 years from the Chinese National Survey on Students' Constitution and Health in 2010 were included in this study. The adiposity indicators, including weight, body mass index (BMI), waist circumference, waist-to-height ratio (WHtR), hip circumference, body adiposity index (BAI), waist-to-hip ratio (WHR) and skinfold thickness, were converted into z-scores before use. The associations between elevated BP and adiposity indicators z-scores were assessed by using logistic regression model and area under the receiver operating characteristic curve (AUC). In general, BAI, BMI and WHtR z-scores were superior for predicting elevated BP compared with weight, waist circumference, hip circumference, WHR and skinfold thickness z-scores. In both sexes, BMI z-score revealed slightly higher AUCs than other indicators. Our findings suggest that general adiposity indicators were equivalent, if not superior, to abdominal adiposity indicators to predict elevated BP. BMI could be a better predictor of elevated BP than other studied adiposity indicators in children.

  19. Elevated intrabolus pressure identifies obstructive processes when integrated relaxation pressure is normal on esophageal high-resolution manometry.

    Science.gov (United States)

    Quader, Farhan; Reddy, Chanakyaram; Patel, Amit; Gyawali, C Prakash

    2017-07-01

    Elevated integrated relaxation pressure (IRP) on esophageal high-resolution manometry (HRM) identifies obstructive processes at the esophagogastric junction (EGJ). Our aim was to determine whether intrabolus pressure (IBP) can identify structural EGJ processes when IRP is normal. In this observational cohort study, adult patients with dysphagia and undergoing HRM were evaluated for endoscopic evidence of structural EGJ processes (strictures, rings, hiatus hernia) in the setting of normal IRP. HRM metrics [IRP, distal contractile integral (DCI), distal latency (DL), IBP, and EGJ contractile integral (EGJ-CI)] were compared among 74 patients with structural EGJ findings (62.8 ± 1.6 yr, 67.6% women), 27 patients with normal EGD (52.9 ± 3.2 yr, 70.3% women), and 21 healthy controls (27.6 ± 0.6 yr, 52.4% women). Findings were validated in 85 consecutive symptomatic patients to address clinical utility. In the primary cohort, mean IBP (18.4 ± 0.9 mmHg) was higher with structural EGJ findings compared with dysphagia with normal EGD (13.5 ± 1.1 mmHg, P = 0.002) and healthy controls (10.9 ± 0.9 mmHg, P 0.05 for each comparison). During multiple rapid swallows, IBP remained higher in the structural findings group compared with controls ( P = 0.02). Similar analysis of the prospective validation cohort confirmed IBP elevation in structural EGJ processes, but correlation with dysphagia could not be demonstrated. We conclude that elevated IBP predicts the presence of structural EGJ processes even when IRP is normal, but correlation with dysphagia is suboptimal. NEW & NOTEWORTHY Integrated relaxation pressure (IRP) above the upper limit of normal defines esophageal outflow obstruction using high-resolution manometry. In patients with normal IRP, elevated intrabolus pressure (IBP) can be a surrogate marker for a structural restrictive or obstructive process at the esophagogastric junction (EGJ). This has the potential to augment the clinical value of

  20. Investigation and modelling of the alkaline release and transport during coal combustion at elevated pressures. Final report; Untersuchung und Modellierung der Freisetzungs- und Transportvorgaenge von Alkalien bei der Kohleverbrennung unter hohen Druecken. Untersuchungen mit der Hochdruck-Hochtemperatur-Thermowaage, Alkalienanalysen in Rohkohlen und Feuerungsversuche in der Druckwirbelschichtanlage FRED (DMT). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bonn, B.; Steffin, C.; Busch, U.; Mayer, M.

    2000-07-01

    In this joint research project DMT investigated the release (and incorporation) of alkalis of the coal mineral matter to clear up the affecting mechanisms during combustion at elevated pressure. In the experiments parameter like the ambient gas and the ash composition, pressure and heating rate were varied. The experiments were conducted in DMT's high-temperature and high-pressure Thermogravimetric-Analyser (TGA) and the DMT Pressurised Fluidised Bed Combustor (PFBC). TGA-Experiments: A model compounds for the alkali sodium chloride and for the mineral matter metakaoline were used. The chemical properties (basicity) of metakaoline was modified by adding CaO. The commonly accepted physical volatilization process of the alkali from the ash was not confirmed by TGA experiments. The alkali release must be regarded as a desorption mechanism of the sodium chloride from the metakaoline surface. The desorption of the alkali is not affected by chemical composition of the mineral matter but is strongly influenced by gas phase oxygen species and pressure. PFBC-Experiments: The rig was operated with a fluidised bed temperature of 920 C and a pressure of 7 bar. The online/in-situ alkali detection was based on the excimer laser induced fragmentation fluorescence ELIF. The alkali content of the coal was varied by addition of sodium acetate and sodium chloride. Kaoline was used as gettermaterial for mitigation of alkali emissions. Furthermore, the influence of limestone on the alkali release was investigated. Among other results, the experiments showed that the alkali emissions of the lignite are 50-100 times higher than those of the bituminous coal and if limestone for capturing SO{sub 2} is added to the combustor the alkali chloride emissions increase rapidly. (orig.) [German] Im Rahmen des o.g. Gemeinschaftsprojekts untersuchte die DMT die Freisetzung (und Einbindung) der Alkalien aus der Mineralsubstanz von Kohlen zur Aufklaerung der beeinflussenden Mechanismen bei der

  1. High temperature gas cleaning for pressurized gasification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Alden, H.; Hagstroem, P.; Hallgren, A.; Waldheim, L. [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    The purpose of the project was to build an apparatus to study pressurized, high temperature gas cleaning of raw gasification gas generated from biomass. A flexible and easy to operate pressurized apparatus was designed and installed for the investigations in high temperature gas cleaning by means of thermal, catalytic or chemical procedures. A semi continuos fuel feeding concept, at a maximum rate of 700 g/h, allowed a very constant formation of a gas product at 700 deg C. The gas product was subsequently introduced into a fixed bed secondary reactor where the actual gas cleanup or reformation was fulfilled. The installation work was divided into four work periods and apart from a few delays the work was carried out according to the time plan. During the first work period (January - June 1994) the technical design, drawings etc. of the reactor and additional parts were completed. All material for the construction was ordered and the installation work was started. The second work period (July - December 1994) was dedicated to the construction and the installation of the different components. Initial tests with the electrical heating elements, control system and gas supply were assigned to the third work period (January - June 1995). After the commissioning and the resulting modifications, initial pyrolysis and tar decomposition experiments were performed. During the fourth and final work period, (June - December 1995) encouraging results from first tests allowed the experimental part of the project work to commence, however in a slightly reduced program. The experimental part of the project work comparatively studied tar decomposition as a function of the process conditions as well as of the choice of catalyst. Two different catalysts, dolomite and a commercial Ni-based catalyst, were evaluated in the unit. Their tar cracking ability in the pressure interval 1 - 20 bar and at cracker bed temperatures between 800 - 900 deg C was compared. Long term tests to study

  2. Integration optimisation of elevated pressure air separation unit with gas turbine in an IGCC power plant

    International Nuclear Information System (INIS)

    Han, Long; Deng, Guangyi; Li, Zheng; Wang, Qinhui; Ileleji, Klein E.

    2017-01-01

    Highlights: • IGCC thermodynamic model was setup carefully. • Simulations focus on integration between an elevated pressure ASU with gas turbine. • Different recommended solutions from those of low pressure ASUs are figured out. • Full N 2 injection and 80% air extraction was suggested as the optimum integration. - Abstract: The integration optimisation between an elevated pressure air separation unit (EP-ASU) and gas turbine is beneficial to promote net efficiency of an integrated gasification combined cycle (IGCC) power plant. This study sets up the thermodynamic model for a 400 MW plant specially coupled with an EP-ASU, aiming to examine system performances under different integrations and acquire the optimum solution. Influences of air extraction rate at conditions of without, partial and full N 2 injection, as well as the effects of N 2 injection rate when adopting separate ASU, partial and full integrated ASU were both analysed. Special attention has been paid to performance differences between utilising an EP-ASU and a low pressure unit. Results indicated that integration solution with a separate EP-ASU or without N 2 injection would not be reasonable. Among various recommended solutions for different integration conditions, N 2 injection rate increased with the growth of air extraction rate. The integration with an air extraction rate of 80% and full N 2 injection was suggested as the optimum solution. It is concluded that the optimum integration solution when adopting an EP-ASU is different from that using a low pressure one.

  3. Hydrodynamics in a cocurrent gas-liquid trickle bed at elevated pressures

    OpenAIRE

    Wammes, W.J.A.; Middelkamp, J.; Huisman, W.J.; Huisman, W.J.; de Baas, C.M.; de Baas, C.M.; Westerterp, K.R.

    1991-01-01

    Data on design and operation of trickle beds at elevated pressures are scarce. In this study the influence of the gas density on the liquid holdup, the pressure drop, and the transition between trickle and pulse flow has been investigated in a tricklebed reactor operating up to 7.5 MPa and with nitrogen or helium as the gas phase. Gas-liquid interfacial areas have been determined up to 5.0 MPa by means of CO2 absorption from CO2/N2 gas mixtures into amine solutions. A comparison of the result...

  4. Calpain: a molecule to induce AIF-mediated necroptosis in RGC-5 following elevated hydrostatic pressure

    Science.gov (United States)

    2014-01-01

    Background RIP3 (Receptor-interacting protein 3) pathway was mainly described as the molecular mechanism of necroptosis (programmed necrosis). But recently, non-RIP3 pathways were found to mediate necroptosis. We deliberate to investigate the effect of calpain, a molecule to induce necroptosis as reported (Cell Death Differ 19:245–256, 2012), in RGC-5 following elevated hydrostatic pressure. Results First, we identified the existence of necroptosis of RGC-5 after insult by using necrostatin-1 (Nec-1, necroptosis inhibitor) detected by flow cytometry. Immunofluorescence staining and western blot were used to detect the expression of calpain. Western blot analysis was carried out to describe the truncated AIF (tAIF) expression with or without pretreatment of ALLN (calpain activity inhibitor). Following elevated hydrostatic pressure, necroptotic cells pretreated with or without ALLN was stained by Annexin V/PI, The activity of calpain was also examined to confirm the inhibition effect of ALLN. The results showed that after cell injury there was an upregulation of calpain expression. Upon adding ALLN, the calpain activity was inhibited, and tAIF production was reduced upon injury along with the decreased number of necroptosis cells. Conclusion Our study found that calpain may induce necroptosis via tAIF-modulation in RGC-5 following elevated hydrostatic pressure. PMID:24884644

  5. Soot particle size measurements in ethylene diffusion flames at elevated pressures

    KAUST Repository

    Steinmetz, Scott

    2016-05-07

    Soot particle size is investigated in laminar nitrogen-diluted ethylene coflow diffusion flames at 4, 8, 12 and 16 atm. Line of sight attenuation and scattering are used to measure two-dimensional soot volume fraction and particle size fields for the first time at elevated pressures. Soot volume fraction dependence on pressure is consistent with the observations of similar studies, scaling approximately with the square of pressure. Scattering intensity is analyzed through Rayleigh and Rayleigh-Debye-Gans polydisperse fractal aggregate theories to provide two estimates of particle size. An increase in overall particle sizes with pressure is found, consistent with similar one-dimensional studies. Particle diameters in the annulus of the flame increase faster with pressure than those on centerline. Contrary to previous studies, the dependence of particle size on pressure was found to taper off between 8 and 12 atm, with little observed growth beyond 12 atm. The measurements provide additional data for one of the International Sooting Flame (ISF) workshop\\'s target pressurized flames.

  6. Elevated plasma endothelin-1 and pulmonary arterial pressure in children exposed to air pollution.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J; Reed, William

    2007-08-01

    Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O(3) that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. We conducted a study of 81 children, 7.9 +/- 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O(3) levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 mum in aerodynamic diameter (PM(2.5)) before endothelin-1 measurement (p = 0.03). Chronic exposure of children to PM(2.5) is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure.

  7. Elevated Plasma Endothelin-1 and Pulmonary Arterial Pressure in Children Exposed to Air Pollution

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J.; Reed, William

    2007-01-01

    Background Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. Objectives The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O3 that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. Methods We conducted a study of 81 children, 7.9 ± 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O3 levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Results Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 μm in aerodynamic diameter (PM2.5) before endothelin-1 measurement (p = 0.03). Conclusions Chronic exposure of children to PM2.5 is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure. PMID:17687455

  8. Elevated pulse pressure is associated with hemolysis, proteinuria and chronic kidney disease in sickle cell disease.

    Directory of Open Access Journals (Sweden)

    Enrico M Novelli

    Full Text Available A seeming paradox of sickle cell disease is that patients do not suffer from a high prevalence of systemic hypertension in spite of endothelial dysfunction, chronic inflammation and vasculopathy. However, some patients do develop systolic hypertension and increased pulse pressure, an increasingly recognized major cardiovascular risk factor in other populations. Hence, we hypothesized that pulse pressure, unlike other blood pressure parameters, is independently associated with markers of hemolytic anemia and cardiovascular risk in sickle cell disease. We analyzed the correlates of pulse pressure in patients (n  =  661 enrolled in a multicenter international sickle cell trial. Markers of hemolysis were analyzed as independent variables and as a previously validated hemolytic index that includes multiple variables. We found that pulse pressure, not systolic, diastolic or mean arterial pressure, independently correlated with high reticulocyte count (beta  =  2.37, p  =  0.02 and high hemolytic index (beta  =  1.53, p = 0.002 in patients with homozygous sickle cell disease in two multiple linear regression models which include the markers of hemolysis as independent variables or the hemolytic index, respectively. Pulse pressure was also independently associated with elevated serum creatinine (beta  =  3.21, p  =  0.02, and with proteinuria (beta  =  2.52, p  =  0.04. These results from the largest sickle cell disease cohort to date since the Cooperative Study of Sickle Cell Disease show that pulse pressure is independently associated with hemolysis, proteinuria and chronic kidney disease. We propose that high pulse pressure may be a risk factor for clinical complications of vascular dysfunction in sickle cell disease. Longitudinal and mechanistic studies should be conducted to confirm these hypotheses.

  9. Density and Viscosity Measurement of Diesel Fuels at Combined High Pressure and Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Carl Schaschke

    2013-07-01

    Full Text Available We report the measurement of the viscosity and density of various diesel fuels, obtained from British refineries, at elevated pressures up to 500 MPa and temperatures in the range 298 K to 373 K. The measurement and prediction procedures of fluid properties under high pressure conditions is of increasing interest in many processes and systems including enhanced oil recovery, automotive engine fuel injection, braking, and hydraulic systems. Accurate data and understanding of the fluid characteristic in terms of pressure, volume and temperature is required particularly where the fluid is composed of a complex mixture or blend of aliphatic or aromatic hydrocarbons. In this study, high pressure viscosity data was obtained using a thermostatically-controlled falling sinker-type high pressure viscometer to provide reproducible and reliable viscosity data based on terminal velocity sinker fall times. This was supported with density measurements using a micro-pVT device. Both high-pressure devices were additionally capable of illustrating the freezing points of the hydrocarbon mixtures. This work has, thus, provided data that can extend the application of mixtures of commercially available fuels and to test the validity of available predictive density and viscosity models. This included a Tait-style equation for fluid compressibility prediction. For complex diesel fuel compositions, which have many unidentified components, the approach illustrates the need to apply appropriate correlations, which require accurate knowledge or prediction of thermodynamic properties.

  10. Myocardial Ischaemia, Coronary Atherosclerosis and Pulmonary Pressure Elevation in Antiphospholipid Syndrome Patients.

    Science.gov (United States)

    Padjas, Agnieszka; Płazak, Wojciech; Celińska-Lowenhoff, Magdalena; Mazurek, Adam; Perricone, Carlo; Podolec, Piotr; Musiał, Jacek

    2016-01-01

    Thrombotic events in antiphospholipid syndrome (APS) involve venous and arterial circulation with the possible involvement of coronary or pulmonary microcirculation. To evaluate the influence of antiphospholipid antibodies (aPL) and on myocardial ischaemia assessed by single-photon emission computerized tomography (SPECT), coronary atherosclerosis assessed by multidetector computerized tomography (MDCT) and pulmonary pressure assessed by transthoracic echocardiography (TTE) in patients with primary antiphospholipid syndrome (PAPS). TTE, SPECT (Tc 99m sestamibi) and MDCT-based coronary calcium scoring were performed in 26 consecutive PAPS patients (20 females, 6 males, aged 20-61, mean 39.7) without any signs of other autoimmunological disease and without clinical symptoms of heart disease. Out of 26 patients, TEE showed normal left and right ventricle function in 25 (96.2%) and elevated (≥ 30 mm Hg) right ventricle systolic pressure in 7 (26.9%) patients. SPECT revealed myocardial perfusion defects in 15 (57.7%) patients: exercise-induced in 6 (23.1%) and persistent in 11 (42.3%). MDCT revealed coronary calcifications in 4 (15.4%) patients. The number of plaques ranged from 1 to 11 (median 2), volume 3-201.7 mm³ (median 7), calcium scores 1.3-202.6 (median 5.7). In the group with perfusion defects or coronary calcifications (n = 15), all the patients showed elevated aCL IgG. In most of the relatively young APS patients, without any symptoms of ischemic heart disease, SPECT showed myocardial perfusion defects, and coronary calcifications in 1/6 of them. Right ventricle systolic pressure was elevated in 1/4 of APS patients. These pathologies, well known as cardiovascular risk markers, were associated with elevated levels of the IgG class of both anti-cardiolipin and antiB2 GPI antibodies. Thus, in a high percentage of APS patients, clinically silent myocardial ischaemia, pulmonary pressure elevation and coronary atherosclerosis are present and related to the

  11. Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures

    Directory of Open Access Journals (Sweden)

    Pešić Radojica

    2015-01-01

    Full Text Available The aim of this work was the experimental investigation of the particle friction factor for air flow through packed bed of particles at ambient and elevated temperatures. The experiments were performed by measuring the pressure drop across the packed bed, heated to the desired temperature by hot air. Glass spherical particles of seven different diameters were used. The temperature range of the air flowing through the packed bed was from 20ºC to 350ºC and the bed voidages were from 0.3574 to 0.4303. The obtained results were correlated using a number of available literature correlations. The overall best fit of all of the experimental data was obtained using Ergun [1] equation, with mean absolute deviation of 10.90%. Ergun`s equation gave somewhat better results in correlating the data at ambient temperature with mean absolute deviation of 9.77%, while correlation of the data at elevated temperatures gave mean absolute deviation of 12.38%. The vast majority of the correlations used gave better results when applied to ambient temperature data than to the data at elevated temperatures. Based on the results obtained, Ergun [1] equation is proposed for friction factor calculation both at ambient and at elevated temperatures. [Projekat Ministarstva nauke Republike Srbije, br. ON172022

  12. Elevated intracranial pressure and reversible eye-tracking changes detected while viewing a film clip.

    Science.gov (United States)

    Kolecki, Radek; Dammavalam, Vikalpa; Bin Zahid, Abdullah; Hubbard, Molly; Choudhry, Osamah; Reyes, Marleen; Han, ByoungJun; Wang, Tom; Papas, Paraskevi Vivian; Adem, Aylin; North, Emily; Gilbertson, David T; Kondziolka, Douglas; Huang, Jason H; Huang, Paul P; Samadani, Uzma

    2018-03-01

    OBJECTIVE The precise threshold differentiating normal and elevated intracranial pressure (ICP) is variable among individuals. In the context of several pathophysiological conditions, elevated ICP leads to abnormalities in global cerebral functioning and impacts the function of cranial nerves (CNs), either or both of which may contribute to ocular dysmotility. The purpose of this study was to assess the impact of elevated ICP on eye-tracking performed while patients were watching a short film clip. METHODS Awake patients requiring placement of an ICP monitor for clinical purposes underwent eye tracking while watching a 220-second continuously playing video moving around the perimeter of a viewing monitor. Pupil position was recorded at 500 Hz and metrics associated with each eye individually and both eyes together were calculated. Linear regression with generalized estimating equations was performed to test the association of eye-tracking metrics with changes in ICP. RESULTS Eye tracking was performed at ICP levels ranging from -3 to 30 mm Hg in 23 patients (12 women, 11 men, mean age 46.8 years) on 55 separate occasions. Eye-tracking measures correlating with CN function linearly decreased with increasing ICP (p short film clip. These results suggest that eye tracking may be used as a noninvasive, automatable means to quantitate the physiological impact of elevated ICP, which has clinical application for assessment of shunt malfunction, pseudotumor cerebri, concussion, and prevention of second-impact syndrome.

  13. Equilibrium moisture content of radiata pine at elevated temperature and pressure reveals measurement challenges

    DEFF Research Database (Denmark)

    Pearson, Hamish; Gabbitas, Brian; Ormarsson, Sigurdur

    2012-01-01

    moisture contents were attributed to condensation of liquid water on the specimen with subsequent evaporation at a rate that was too slow for the moisture content to reach equilibrium before it was measured. Reliable EMC data at elevated temperatures require (1) tight process control of experimental......Relatively few studies have been performed on the equilibrium moisture content (EMC) of wood under conditions of elevated temperature and pressure. Eight studies indicated that EMC near saturation decreased between 100 and 150 °C, whilst five studies indicated that EMC increased. The aim...... of this study was to identify the likely source of the disagreement using radiata pine (Pinus radiata D. Don) sapwood which was conditioned to a moisture content of around 3 % and then exposed for 1 h at 150 °C and relative humidities of either 50, 70 or 90 %. Mean values of EMC, obtained through in situ...

  14. Liquid oxygen liquid acquisition device bubble point tests with high pressure lox at elevated temperatures

    Science.gov (United States)

    Jurns, J. M.; Hartwig, J. W.

    2012-04-01

    When transferring propellant in space, it is most efficient to transfer single phase liquid from a propellant tank to an engine. In earth's gravity field or under acceleration, propellant transfer is fairly simple. However, in low gravity, withdrawing single-phase fluid becomes a challenge. A variety of propellant management devices (PMDs) are used to ensure single-phase flow. One type of PMD, a liquid acquisition device (LAD) takes advantage of capillary flow and surface tension to acquire liquid. The present work reports on testing with liquid oxygen (LOX) at elevated pressures (and thus temperatures) (maximum pressure 1724 kPa and maximum temperature 122 K) as part of NASA's continuing cryogenic LAD development program. These tests evaluate LAD performance for LOX stored in higher pressure vessels that may be used in propellant systems using pressure fed engines. Test data shows a significant drop in LAD bubble point values at higher liquid temperatures, consistent with lower liquid surface tension at those temperatures. Test data also indicates that there are no first order effects of helium solubility in LOX on LAD bubble point prediction. Test results here extend the range of data for LOX fluid conditions, and provide insight into factors affecting predicting LAD bubble point pressures.

  15. Intracranial hemorrhage in normotensive and hypertensive patients receiving streptokinase after decreasing elevated blood pressure

    Directory of Open Access Journals (Sweden)

    H Shemirani

    2005-09-01

    Full Text Available Background: Many patients with suspected acute myocardial infarction (AMI and eligible for thrombolytic therapy may not be treated because of association between hemorrhagic complications especially intracranial hemorrhage (ICH, and severe hypertension (HTN at presentation. Unfortunately, this leads to under use or delay in thrombolytic therapy. We assessed effect of decreasing elevated blood pressure before thrombolytic therapy in order to reduce the incidence of ICH without increasing mortality rate. Methods: This observational and analytical cohort study enrolled 293 patients (215males and 78 female with STsegment elevation (AMI that were hospitalized in emergency department of Noor hospital, Isfahan, Iran. Severe hypertension (blood pressure ≥180/110mmHg was diagnosed in 132 patients. All of them received 1.5 million units streptokinase within one hour intravenously. In the hypertensive group, elevated blood pressure was lowered to less than180/110mmhg before thrombolysis and they were observed to detect development of symptomatic ICH and they underwent Brain CT scan, if required. Results: The incidence of total stroke, ICH and death were 1.4%, 0.7% and 4.8%, respectively. The incidence of death and ICH in patients with severe hypertension was less than control group (P value=0.13 and 0.59, respectively Conclusion: Although we did not find any increase in ICH incidence in severe hypertensive patients treated be streptokinase due to AMI, but we recommend a multi-centric study with more cases and varied thrombolytic protocols. Key words: Acute myocardial infarction, Intracranial hemorrhage, Thrombolytic therapy

  16. Serum IL-6: a candidate biomarker for intracranial pressure elevation following isolated traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Ward Norman H

    2010-03-01

    Full Text Available Abstract Background Increased intracranial pressure (ICP is a serious, life-threatening, secondary event following traumatic brain injury (TBI. In many cases, ICP rises in a delayed fashion, reaching a maximal level 48-96 hours after the initial insult. While pressure catheters can be implanted to monitor ICP, there is no clinically proven method for determining a patient's risk for developing this pathology. Methods In the present study, we employed antibody array and Luminex-based screening methods to interrogate the levels of inflammatory cytokines in the serum of healthy volunteers and in severe TBI patients (GCS≤8 with or without incidence of elevated intracranial pressure (ICP. De-identified samples and ELISAs were used to confirm the sensitivity and specificity of IL-6 as a prognostic marker of elevated ICP in both isolated TBI patients, and polytrauma patients with TBI. Results Consistent with previous reports, we observed sustained increases in IL-6 levels in TBI patients irrespective of their ICP status. However, the group of patients who subsequently experienced ICP ≥ 25 mm Hg had significantly higher IL-6 levels within the first 17 hours of injury as compared to the patients whose ICP remained ≤20 mm Hg. When blinded samples (n = 22 were assessed, a serum IL-6 cut-off of 128 pg/ml correctly identified 85% of isolated TBI patients who subsequently developed elevated ICP, and values between these cut-off values correctly identified 75% of all patients whose ICP remained ≤20 mm Hg throughout the study period. In contrast, the marker had no prognostic value in predicting elevated ICP in polytrauma patients with TBI. When the levels of serum IL-6 were assessed in patients with orthopedic injury (n = 7 in the absence of TBI, a significant increase was found in these patients compared to healthy volunteers, albeit lower than that observed in TBI patients. Conclusions Our results suggest that serum IL-6 can be used for the

  17. Effect of renal venous pressure elevation on tubular sodium and water reabsorption in the dog kidney

    DEFF Research Database (Denmark)

    Abildgaard, U; Amtorp, O; Holstein-Rathlou, N H

    1988-01-01

    of [51Cr]EDTA was used as a measure of the rate of glomerular filtration (GFR). GFR, urinary excretion rates of sodium and water, and lithium clearance were used for assessing the absolute and fractional reabsorption rates of sodium and water in the proximal as well as in more distal segments......This study was performed in order to quantify the effects of renal venous pressure (RVP) elevation on absolute and fractional reabsorption rates of sodium and water in proximal and distal segments of the nephron in dog kidneys. Renal blood flow (RBF) was measured electromagnetically. Clearance...

  18. Additive pressures of elevated sea surface temperatures and herbicides on symbiont-bearing foraminifera.

    Directory of Open Access Journals (Sweden)

    Joost W van Dam

    Full Text Available Elevated ocean temperatures and agrochemical pollution individually threaten inshore coral reefs, but these pressures are likely to occur simultaneously. Experiments were conducted to evaluate the combined effects of elevated temperature and the photosystem II (PSII inhibiting herbicide diuron on several types of symbiotic algae (diatom, dinoflagellate or rhodophyte of benthic foraminifera in hospite. Diuron was shown to evoke a direct effect on photosynthetic efficiency (reduced effective PSII quantum yield ΔF/F'(m, while elevated temperatures (>30 °C, only 2 °C above current average summer temperatures were observed to impact photosynthesis more indirectly by causing reductions in maximum PSII quantum yield (F(v/F(m, interpreted as photodamage. Additionally, elevated temperatures were shown to cause bleaching through loss of chlorophyll a in foraminifera hosting either diatoms or dinoflagellates. A significant linear correlation was found between reduced F(v/F(m and loss of chlorophyll a. In most cases, symbionts within foraminifera proved more sensitive to thermal stress in the presence of diuron (≥ 1 µg L(-1. The mixture toxicity model of Independent Action (IA described the combined effects of temperature and diuron on the photosystem of species hosting diatoms or dinoflagellates convincingly and in agreement with probabilistic statistics, so a response additive joint action can be assumed. We thus demonstrate that improving water quality can improve resilience of symbiotic phototrophs to projected increases in ocean temperatures. As IA described the observed combined effects from elevated temperature and diuron stress it may therefore be employed for prediction of untested mixtures and for assessing the efficacy of management measures.

  19. Additive pressures of elevated sea surface temperatures and herbicides on symbiont-bearing foraminifera.

    Science.gov (United States)

    van Dam, Joost W; Negri, Andrew P; Mueller, Jochen F; Altenburger, Rolf; Uthicke, Sven

    2012-01-01

    Elevated ocean temperatures and agrochemical pollution individually threaten inshore coral reefs, but these pressures are likely to occur simultaneously. Experiments were conducted to evaluate the combined effects of elevated temperature and the photosystem II (PSII) inhibiting herbicide diuron on several types of symbiotic algae (diatom, dinoflagellate or rhodophyte) of benthic foraminifera in hospite. Diuron was shown to evoke a direct effect on photosynthetic efficiency (reduced effective PSII quantum yield ΔF/F'(m)), while elevated temperatures (>30 °C, only 2 °C above current average summer temperatures) were observed to impact photosynthesis more indirectly by causing reductions in maximum PSII quantum yield (F(v)/F(m)), interpreted as photodamage. Additionally, elevated temperatures were shown to cause bleaching through loss of chlorophyll a in foraminifera hosting either diatoms or dinoflagellates. A significant linear correlation was found between reduced F(v)/F(m) and loss of chlorophyll a. In most cases, symbionts within foraminifera proved more sensitive to thermal stress in the presence of diuron (≥ 1 µg L(-1)). The mixture toxicity model of Independent Action (IA) described the combined effects of temperature and diuron on the photosystem of species hosting diatoms or dinoflagellates convincingly and in agreement with probabilistic statistics, so a response additive joint action can be assumed. We thus demonstrate that improving water quality can improve resilience of symbiotic phototrophs to projected increases in ocean temperatures. As IA described the observed combined effects from elevated temperature and diuron stress it may therefore be employed for prediction of untested mixtures and for assessing the efficacy of management measures.

  20. The Risk of Intraocular Pressure Elevation in Pediatric Non-infectious Uveitis

    Science.gov (United States)

    Kothari, Srishti; Foster, C. Stephen; Pistilli, Maxwell; Liesegang, Teresa L.; Daniel, Ebenezer; Sen, H. Nida; Suhler, Eric B.; Thorne, Jennifer E.; Jabs, Douglas A.; Levy-Clarke, Grace A.; Nussenblatt, Robert B.; Rosenbaum, James T.; Lawrence, Scott D.; Kempen, John H.

    2015-01-01

    Purpose To characterize the risk and risk factors for intraocular pressure (IOP) elevation in pediatric non-infectious uveitis. Design Multi-center retrospective cohort study. Participants Nine hundred sixteen children (1593 eyes) uveitis followed between January 1978 through December 2007 at five academic uveitis centers in United States. Methods Medical records review by trained, certified experts. Main outcome measures Prevalence and incidence of IOP≥21 and ≥30mmHg and incidence of a rise in IOP by ≥10mmHg. To avoid under ascertainment, outcomes were counted as present when IOP-lowering therapies were in use. Results Initially 251 (15.8%) and 46 eyes (2.9%) had IOP≥21 and ≥30mmHg, respectively. Factors associated with presenting IOP elevation included age 6–12 years (versus other pediatric ages), prior cataract surgery (adjusted odds ratio≥21mmHg [aOR21]=2.42, P=0.01), pars plana vitrectomy (adjusted odds ratio≥30mmHg[aOR30]=11.1, P=0.03), duration of uveitis ≥6 months (aORs30 up to 11.8, Puveitis. Statistically significant risk factors include IOP elevation or use of IOP-lowering treatment in the contralateral eye and local corticosteroid use – that demonstrated a dose-and route of administration-dependent relationship. In contrast, use of immunosuppressive drug therapy did not increase such risk. Pediatric eyes with non-infectious uveitis should be followed closely for IOP elevation when strong risk factors such as the use of local corticosteroids and contralateral IOP elevation are present. PMID:26233626

  1. Turbulent burning characteristics of FACE-C gasoline and TPRF blend associated with the same RON at elevated pressures

    KAUST Repository

    Mannaa, Ossama; Brequigny, P.; Mounaim-Rousselle, C.; Foucher, F.; Chung, Suk-Ho; Roberts, William L.

    2018-01-01

    morphology induced by the simultaneous existences of different turbulent length scales and the susceptibility to develop cellular structures at elevated pressures (through the Darrieus-Landau instability). Measurements were performed in a well

  2. Clinical analysis of modified trabeculectomy in glaucoma surgery with high elevated intraocular pressure

    Directory of Open Access Journals (Sweden)

    Cang-Xia Zhang

    2013-10-01

    Full Text Available AIM: To make a retrospective analysis of the clinical data of modified trabeculectomy in treating glaucoma surgery with high elevated intraocular pressure retrospectively and evaluate the effect of modified trabeculectomy.METHODS:One hundred acute angle-closure glaucoma patients(100 eyeswith persistent high intraocular pressure were divided into treatment group(45 eyesand control group(55 eyes. Patients in treatment group was treated with by trabeculectomy, while those in control group received modified trabeculectomy. The modified measures include stellate ganglion block preoperative, topical anesthesia and local anesthesia with 20g/L lidocaine cotton-piece, to make scleral flap with sclerotome, to release aqueous humor outflow slowly after paracentesis of anterior chamber, and using mydriatic and cycloplegic during and after surgery.RESULTS: The incidence of operation complicationin control group was lower than that in treatment group. The differences were statistically significant(Pt=9.1535, Pt=39.8010, Pt=11.3219, PCONCLUSION: The modified trabeculectomy applied in the treatment of glaucoma with persistent high intraocular pressure can not only save the visual function of connection part to a certain extent, but also reduce the incidence of serious complications. It can obtain better intraocular pressure, shorten the average hospitalization days, decrease the expenses and increase patients satisfaction.

  3. Preschool Children with Obstructive Sleep Apnea: The Beginnings of Elevated Blood Pressure?

    Science.gov (United States)

    Nisbet, Lauren C.; Yiallourou, Stephanie R.; Biggs, Sarah N.; Nixon, Gillian M.; Davey, Margot J.; Trinder, John A.; Walter, Lisa M.; Horne, Rosemary S. C.

    2013-01-01

    Study Objectives: In adults and older children, snoring and obstructive sleep apnea (OSA) are associated with elevated blood pressure (BP). However, BP has not been assessed in preschool children, the age of highest OSA prevalence. We aimed to assess overnight BP in preschool children with snoring and OSA using pulse transit time (PTT), an inverse continuous indicator of BP changes. Design: Overnight polysomnography including PTT. Children were grouped according to their obstructive apnea-hypopnea index (OAHI); control (no snoring, with OAHI of one event or less per hour), primary snoring (OAHI one event or less per hour), mild OSA (OAHI greater than one event to five events per hour) and moderate-severe OSA (OAHI more than five events per hour). Setting: Pediatric sleep laboratory. Patients: There were 128 clinically referred children (aged 3-5 years) and 35 nonsnoring community control children. Measurement and Results: PTT was averaged for each 30-sec epoch of rapid eye movement (REM) or nonrapid eye movement (NREM) sleep and normalized to each child's mean wake PTT. PTT during NREM was significantly higher than during REM sleep in all groups (P Biggs SN; Nixon GM; Davey MJ; Trinder JA; Walter LM; Horne RSC. Preschool children with obstructive sleep apnea: the beginnings of elevated blood pressure? SLEEP 2013;36(8):1219-1226. PMID:23904682

  4. Prevalence of elevated mean arterial pressure and how fitness moderates its association with BMI in youth.

    Science.gov (United States)

    Ogunleye, Ayodele A; Sandercock, Gavin R; Voss, Christine; Eisenmann, Joey C; Reed, Katharine

    2013-11-01

    Cardiorespiratory fitness is known to be cardioprotective and its association with the components of the metabolic syndrome in children is becoming clearer. The aim of the present study was to examine the extent to which cardiorespiratory fitness may offset the weight-related association with mean arterial pressure (MAP) in schoolchildren. Cross-sectional study. Schoolchildren from the East of England, U.K. A total of 5983 (48% females) schoolchildren, 10 to 16 years of age, had height, weight and blood pressure measured by standard procedures and cardiorespiratory fitness assessed by the 20 m shuttle-run test. Participants were classified as fit or unfit using internationally accepted fitness cut-off points; and as normal weight, overweight or obese based on BMI, again using international cut-off points. Age-adjusted ANCOVA was used to determine the main effects and interaction of fitness and BMI on MAP Z-score. Logistic regression models were used to estimate odds ratios of elevated MAP. Prevalence of elevated MAP in schoolchildren was 14.8% overall and 35.7% in those who were obese-unfit. Approximately 21% of participants were overweight and 5% obese, while 23% were classified as unfit. MAP generally increased across BMI categories and was higher in the aerobically unfit participants. Obese-fit males had lower MAP compared with obese-unfit males (P < 0.001); this trend was similar in females (P = 0.05). Increasing fitness level may have a positive impact on the weight-related elevations of MAP seen in obese and overweight schoolchildren.

  5. Apraclonidine versus brinzolamide-timolol combination to prevent intraocular pressure elevation after laser capsulotomy

    Directory of Open Access Journals (Sweden)

    Erkan Çelik

    2016-01-01

    Full Text Available AIM: To compare the efficacy of fixed combination of brinzolamide 1% and timolol 0.5%(FCBTwith apraclonidine 0.5%(APRAin preventing intraocular pressure(IOPelevations after neodymium: yttrium-aluminum-garnet(Nd:YAGlaser posterior capsulotomy.METHODS: This prospective randomized clinical study included 90 eyes of 90 consecutive patients who had Nd:YAG laser posterior capsulotomy for posterior capsule opacification(PCO. Patients were randomized to receive APRA(n=45or FCBT(n=45at 1h before laser surgery. A masked observer measured IOP by Goldmann applanation tonometry before the procedure and at 1, 2, 3, 24h and 7d after laser treatment. IOP outcome measures were grouped into the following categories: post laser IOP elevation of 5 to RESULTS:The mean IOP before surgery on the day of the procedure was 14.1±2.1 mm Hg in the APRA group and 13.2±2.1 mm Hg in the FCBT group. There was no statistically significant difference between the APRA and the FCBT groups of baseline IOPs measured(P=0.066. During the follow-up time, the mean IOP was lower in FCBT group, but this was not statistically significant. Six patients(13.3%in APRA group and 4(8.9%in FCBT group had IOP elevations of 5 to P=0.243. IOP elevations of 10 mm Hg or more occurred in 3 eyes(6.7%in the APRA group and 1 eyes(2.2%in the FCBT group; this was not statistically significant(P=0.542. CONCLUSION:Both of APRA and FCBT are effective for prevention and APRA is enough for most of routine cases. FCBT may be an option for the eyes those need more IOP reduction such as pre-existing glaucoma patients who are at higher risk for postoperative IOP elevations.

  6. Childhood obesity and elevated blood pressure in a rural population of northern Greece.

    Science.gov (United States)

    Mavrakanas, Thomas A; Konsoula, Georgia; Patsonis, Ioannis; Merkouris, Bodossakis P

    2009-01-01

    The objective of this study was to determine the prevalence of childhood obesity and elevated blood pressure (BP) in a rural population of northern Greece. In total, 572 schoolchildren between the age of 4 and 10 years were examined. Obesity was defined using three different standards: (1) body mass index (BMI) charts of the French society of Paediatrics (FR), selected because of the low cardiovascular risk profile and low prevalence of obesity in France; (2) United States BMI CDC charts (US), selected because of the high prevalence of childhood obesity in the USA; and the reference curves of the International Obesity Task Force (IOTF). Children with elevated BP were defined as BP > or = 95th percentile for age, gender and height, according to the Greek national charts. The prevalence of obesity for boys was 13.6% (IOTF), 23.7% (US) and 31.7% (FR); for girls 14.4% (IOTF), 21.1% (US) and 35.1% (FR). The prevalence of elevated BP was 7.9% (45 children). It was 5 to 6 times more common for obese than non-obese children to have elevated BP (relative risk of 5.2 to 6.2 and odds ratio 6.3 to 7.7). The results confirm the high prevalence of childhood obesity in Greece, in this study found to be more prevalent in rural than urban Greece. The IOTF criteria tend to underestimate obesity and may not be optimal for use in a primary clinical care setting where the approach is for health education and patient treatment, rather than purely epidemiological. The study also confirms a strong relationship between high BP and increased BMI.

  7. Guar Gum Stimulates Biogenic Sulfide Production at Elevated Pressures: Implications for Shale Gas Extraction.

    Science.gov (United States)

    Nixon, Sophie L; Walker, Leanne; Streets, Matthew D T; Eden, Bob; Boothman, Christopher; Taylor, Kevin G; Lloyd, Jonathan R

    2017-01-01

    Biogenic sulfide production is a common problem in the oil industry, and can lead to costly hydrocarbon processing and corrosion of extraction infrastructure. The same phenomenon has recently been identified in shale gas extraction by hydraulic fracturing, and organic additives in fracturing fluid have been hypothesized to stimulate this process. Constraining the relative effects of the numerous organic additives on microbial metabolism in situ is, however, extremely challenging. Using a bespoke bioreactor system we sought to assess the potential for guar gum, the most commonly used gelling agent in fracturing fluids, to stimulate biogenic sulfide production by sulfate-reducing microorganisms at elevated pressure. Two pressurized bioreactors were fed with either sulfate-amended freshwater medium, or low-sulfate natural surface water, in addition to guar gum (0.05 w/v%) and an inoculum of sulfate-reducing bacteria for a period of 77 days. Sulfide production was observed in both bioreactors, even when the sulfate concentration was low. Analysis of 16S rRNA gene sequences indicate that heterotrophic bacteria closely associated with the genera Brevundimonas and Acinetobacter became enriched early in the bioreactor experiments, followed by an increase in relative abundance of 16S rRNA genes associated with sulfate-reducing bacteria ( Desulfosporosinus and Desulfobacteraceae) at later time points. Results demonstrate that guar gum can stimulate acid- and sulfide-producing microorganisms at elevated pressure, and may have implications for the potential role in microbially induced corrosion during hydraulic fracturing operations. Key differences between experimental and in situ conditions are discussed, as well as additional sources of carbon and energy for biogenic sulfide production during shale gas extraction. Our laboratory approach can be tailored to better simulate deep subsurface conditions in order to probe the role of other fracturing fluid additives and downhole

  8. Guar Gum Stimulates Biogenic Sulfide Production at Elevated Pressures: Implications for Shale Gas Extraction

    Science.gov (United States)

    Nixon, Sophie L.; Walker, Leanne; Streets, Matthew D. T.; Eden, Bob; Boothman, Christopher; Taylor, Kevin G.; Lloyd, Jonathan R.

    2017-01-01

    Biogenic sulfide production is a common problem in the oil industry, and can lead to costly hydrocarbon processing and corrosion of extraction infrastructure. The same phenomenon has recently been identified in shale gas extraction by hydraulic fracturing, and organic additives in fracturing fluid have been hypothesized to stimulate this process. Constraining the relative effects of the numerous organic additives on microbial metabolism in situ is, however, extremely challenging. Using a bespoke bioreactor system we sought to assess the potential for guar gum, the most commonly used gelling agent in fracturing fluids, to stimulate biogenic sulfide production by sulfate-reducing microorganisms at elevated pressure. Two pressurized bioreactors were fed with either sulfate-amended freshwater medium, or low-sulfate natural surface water, in addition to guar gum (0.05 w/v%) and an inoculum of sulfate-reducing bacteria for a period of 77 days. Sulfide production was observed in both bioreactors, even when the sulfate concentration was low. Analysis of 16S rRNA gene sequences indicate that heterotrophic bacteria closely associated with the genera Brevundimonas and Acinetobacter became enriched early in the bioreactor experiments, followed by an increase in relative abundance of 16S rRNA genes associated with sulfate-reducing bacteria (Desulfosporosinus and Desulfobacteraceae) at later time points. Results demonstrate that guar gum can stimulate acid- and sulfide-producing microorganisms at elevated pressure, and may have implications for the potential role in microbially induced corrosion during hydraulic fracturing operations. Key differences between experimental and in situ conditions are discussed, as well as additional sources of carbon and energy for biogenic sulfide production during shale gas extraction. Our laboratory approach can be tailored to better simulate deep subsurface conditions in order to probe the role of other fracturing fluid additives and downhole

  9. Contribution of TRPV1 to microglia-derived IL-6 and NFkappaB translocation with elevated hydrostatic pressure.

    Science.gov (United States)

    Sappington, Rebecca M; Calkins, David J

    2008-07-01

    The authors investigated the contributions of the transient receptor potential vanilloid-1 receptor (TRPV1) and Ca(2+) to microglial IL-6 and nuclear factor kappa B (NFkappaB) translocation with elevated hydrostatic pressure. The authors first examined IL-6 colocalization with the microglia marker Iba-1 in the DBA/2 mouse model of glaucoma to establish relevance. They isolated microglia from rat retina and maintained them at ambient or elevated (+70 mm Hg) hydrostatic pressure in vitro and used ELISA and immunocytochemistry to measure changes in the IL-6 concentration and NFkappaB translocation induced by the Ca(2+) chelator EGTA, the broad-spectrum Ca(2+) channel inhibitor ruthenium red, and the TRPV1 antagonist iodo-resiniferatoxin (I-RTX). They applied the Ca(2+) dye Fluo-4 AM to measure changes in intracellular Ca(2+) at elevated pressure induced by I-RTX and confirmed TRPV1 expression in microglia using PCR and immunocytochemistry. In DBA/2 retina, elevated intraocular pressure increased microglial IL-6 in the ganglion cell layer. Elevated hydrostatic pressure (24 hours) increased microglial IL-6 release, cytosolic NFkappaB, and NFkappaB translocation in vitro. These effects were reduced substantially by EGTA and ruthenium red. Antagonism of TRPV1 in microglia partially inhibited pressure-induced increases in IL-6 release and NFkappaB translocation. Brief elevated pressure (1 hour) induced a significant increase in microglial intracellular Ca(2+) that was partially attenuated by TRPV1 antagonism. Elevated pressure induces an influx of extracellular Ca(2+) in retinal microglia that precedes the activation of NFkappaB and the subsequent production and release of IL-6 and is at least partially dependent on the activation of TRPV1 and other ruthenium red-sensitive channels.

  10. Detection of elevated pulmonary capillary wedge pressure in elderly patients with various cardiac disorders by the Valsalva manoeuvre.

    NARCIS (Netherlands)

    Remmen, J.J.; Aengevaeren, W.R.M.; Verheugt, F.W.A.; Jansen, R.W.M.M.

    2006-01-01

    In the present study, we assessed whether elevated (> or =15 mmHg) PCWP (pulmonary capillary wedge pressure) can be detected using the blood pressure response to the Valsalva manoeuvre in a group of elderly patients with various cardiac disorders, including atrial fibrillation and valvular heart

  11. Barley seed ageing: genetics behind the dry elevated pressure of oxygen ageing and moist controlled deterioration

    Directory of Open Access Journals (Sweden)

    Manuela eNagel

    2016-03-01

    Full Text Available Experimental seed ageing approaches intend to mimic seed deterioration processes to achieve a storage interval reduction. Common methods apply higher seed moisture levels and temperatures. In contrast, the elevated partial pressure of oxygen (EPPO approach treats dry seed stored at ambient temperatures with high oxygen pressure. To analyse the genetic background of seed longevity and the effects of seed ageing under dry conditions, the EPPO approach was applied to the progeny of the Oregon Wolfe Barley (OWB mapping population. In comparison to a non-treated control and a control high-pressure nitrogen treatment, EPPO stored seeds showed typical symptoms of ageing with a significant reduction of normal seedlings, slower germination, and less total germination. Thereby, the parent Dom (OWB-D, carrying dominant alleles, is more sensitive to ageing in comparison to the population mean and in most cases to the parent Rec (OWB-R, carrying recessive alleles. Quantitative trait locus (QTL analyses using 2,832 markers revealed 65 QTLs, including two major loci for seed vigor on 2H and 7H. QTLs for EPPO tolerance were detected on 3H, 4H, and 5H. An applied controlled deterioration (CD treatment (aged at higher moisture level and temperature revealed a tolerance QTL on 5H, indicating that the mechanism of seed deterioration differs in part between EPPO or CD conditions.

  12. Risk of Microgravity-Induced Visual Impairment and Elevated Intracranial Pressure (VIIP)

    Science.gov (United States)

    Otto, Christian

    2011-01-01

    Eight cases identified, represent 23.5% of the 34 crewmembers flown on the ISS, with inflight visual changes and pre-to-postflight refractive changes. In some cases, the changes were transient while in others they are persistent with varying degrees of visual impairment. (1) Decreased intraocular pressure (IOP) postflight was observed in 3 cases. (2) Fundoscopic exams revealed postflight findings of choroidal folds in 4 cases, optic disc edema in 5 cases and presence of cotton wool spots in 3 cases. (3) Optical coherence tomography (OCT) confirmed findings of choroidal folds and disc edema and documented retinal nerve fiber layer thickening (4 cases). (4) Findings from MRI examinations showed posterior globe flattening (5 cases) and optic nerve sheath distension (6 cases). (5) Opening cerebrospinal fluid (CSF) pressure was elevated in 4 cases postflight reflecting raised intracranial pressure. While the etiology remains unknown, hypotheses speculate that venous insufficiency or hypertension in the brain caused by cephalad fluid shifts during spaceflight are possible mechanisms for ocular changes in astronauts.

  13. Numerical Study of Pollutant Emissions in a Jet Stirred Reactor under Elevated Pressure Lean Premixed Conditions

    Directory of Open Access Journals (Sweden)

    Karim Mazaheri

    2016-01-01

    Full Text Available Numerical study of pollutant emissions (NO and CO in a Jet Stirred Reactor (JSR combustor for methane oxidation under Elevated Pressure Lean Premixed (EPLP conditions is presented. A Detailed Flow-field Simplified Chemistry (DFSC method, a low computational cost method, is employed for predicting NO and CO concentrations. Reynolds Averaged Navier Stokes (RANS equations with species transport equations are solved. Improved-coefficient five-step global mechanisms derived from a new evolutionary-based approach were taken as combustion kinetics. For modeling turbulent flow field, Reynolds Stress Model (RSM, and for turbulence chemistry interactions, finite rate-Eddy dissipation model are employed. Effects of pressure (3, 6.5 bars and inlet temperature (408–573 K over a range of residence time (1.49–3.97 ms are numerically examined. A good agreement between the numerical and experimental distribution of NO and CO was found. The effect of decreasing the operating pressure on NO generation is much more than the effect of increase in the inlet temperature.

  14. Modeling carbon dioxide sequestration in saline aquifers: Significance of elevated pressures and salinities

    International Nuclear Information System (INIS)

    Allen, D.E.; Strazisar, B.R.; Soong, Y.; Hedges, S.W.

    2005-01-01

    The ultimate capacity of saline formations to sequester carbon dioxide by solubility and mineral trapping must be determined by simulating sequestration with geochemical models. These models, however, are only as reliable as the data and reaction scheme on which they are based. Several models have been used to make estimates of carbon dioxide solubility and mineral formation as a function of pressure and fluid composition. Intercomparison of modeling results indicates that failure to adjust all equilibrium constants to account for elevated carbon dioxide pressures results in significant errors in both solubility and mineral formation estimates. Absence of experimental data at high carbon dioxide pressures and high salinities make verification of model results difficult. Results indicate standalone solubility models that do not take mineral reactions into account will underestimate the total capacity of aquifers to sequester carbon dioxide in the long term through enhanced solubility and mineral trapping mechanisms. Overall, it is difficult to confidently predict the ultimate sequestration capacity of deep saline aquifers using geochemical models. (author)

  15. Study of creep collapse of tubes subject to external pressure at elevated temperature

    International Nuclear Information System (INIS)

    Takikawa, N.

    1982-01-01

    Intermediate heat exchanger (IHX) tubes of VHTR form the boundary between the primary and secondary coolants of the reactor. The tubes are subject to external pressures at a postulated secondary coolant depressurization accident, which might lead to creep collapse. Therefore, it is necessary to ensure the integrity against creep collapse by analysis. The objective of this work is to study a simplified analytical method for predicting collapse time of a curved tube subjected to an external pressure. The study is made based on the comparison of experimental collapse time of curved and straight tubes. Creep collapse tests were conducted under an elevated temperature and an external pressure. Test results showed that curved tubes had longer collapse time than straight tubes with the same cross sectional ovality. The simplified analytical method for a curved tube is proposed in this report, which is to compute collapse time of a straight tube with the same ovality. And in this method the computed time is considered as collapse time of the curved tube. The above test results show that this simplified method gives the conservative collapse time. And it is confirmed by additional IHX tube tests that the method is applicable to creep collapse analysis of IHX tubes

  16. Experimental apparatus with full optical access for combustion experiments with laminar flames from a single circular nozzle at elevated pressures.

    Science.gov (United States)

    Joo, Peter H; Gao, Jinlong; Li, Zhongshan; Aldén, Marcus

    2015-03-01

    The design and features of a high pressure chamber and burner that is suitable for combustion experiments at elevated pressures are presented. The high pressure combustion apparatus utilizes a high pressure burner that is comprised of a chamber burner module and an easily accessible interchangeable burner module to add to its flexibility. The burner is well suited to study both premixed and non-premixed flames. The optical access to the chamber is provided through four viewports for direct visual observations and optical-based diagnostic techniques. Auxiliary features include numerous access ports and electrical connections and as a result, the combustion apparatus is also suitable to work with plasmas and liquid fuels. Images of methane flames at elevated pressures up to 25 atm and preliminary results of optical-based measurements demonstrate the suitability of the high pressure experimental apparatus for combustion experiments.

  17. Rationale and Design of the Reduce Elevated Left Atrial Pressure in Patients With Heart Failure (Reduce LAP-HF) Trial

    DEFF Research Database (Denmark)

    Hasenfuss, Gerd; Gustafsson, Finn; Kaye, David

    2015-01-01

    OBJECTIVE: Heart failure with preserved ejection fraction (HFpEF) is characterized by elevated left atrial pressure during rest and/or exercise. The Reduce LAP-HF (Reduce Elevated Left Atrial Pressure in Patients With Heart Failure) trial will evaluate the safety and performance of the Interatrial...... Shunt Device (IASD) System II, designed to directly reduce elevated left atrial pressure, in patients with HFpEF. METHODS: The Reduce LAP-HF Trial is a prospective, nonrandomized, open-label trial to evaluate a novel device that creates a small permanent shunt at the level of the atria. A minimum of 60...... patients with ejection fraction ≥40% and New York Heart Association functional class III or IV heart failure with a pulmonary capillary wedge pressure (PCWP) ≥15 mm Hg at rest or ≥25 mm Hg during supine bike exercise will be implanted with an IASD System II, and followed for 6 months to assess the primary...

  18. Systems genetics identifies a role for Cacna2d1 regulation in elevated intraocular pressure and glaucoma susceptibility

    OpenAIRE

    Chintalapudi, Sumana R.; Maria, Doaa; Di Wang, Xiang; Bailey, Jessica N. Cooke; Hysi, Pirro G.; Wiggs, Janey L.; Williams, Robert W.; Jablonski, Monica M.

    2017-01-01

    textabstractGlaucoma is a multi-factorial blinding disease in which genetic factors play an important role. Elevated intraocular pressure is a highly heritable risk factor for primary open angle glaucoma and currently the only target for glaucoma therapy. Our study helps to better understand underlying genetic and molecular mechanisms that regulate intraocular pressure, and identifies a new candidate gene, Cacna2d1, that modulates intraocular pressure and a promising therapeutic, pregabalin, ...

  19. Dual shell pressure balanced reactor vessel. Final project report

    International Nuclear Information System (INIS)

    Robertus, R.J.; Fassbender, A.G.

    1994-10-01

    The Department of Energy's Office of Energy Research (OER) has previously provided support for the development of several chemical processes, including supercritical water oxidation, liquefaction, and aqueous hazardous waste destruction, where chemical and phase transformations are conducted at high pressure and temperature. These and many other commercial processes require a pressure vessel capable of operating in a corrosive environment where safety and economy are important requirements. Pacific Northwest Laboratory (PNL) engineers have recently developed and patented (U.S. patent 5,167,930 December 1, 1992) a concept for a novel Dual Shell Pressure Balanced Vessel (DSPBV) which could solve a number of these problems. The technology could be immediately useful in continuing commercialization of an R ampersand D 100 award-winning technology, Sludge-to-oil Reactor System (STORS), originally developed through funding by OER. Innotek Corporation is a small business that would be one logical end-user of the DSPBV reactor technology. Innotek is working with several major U.S. engineering firms to evaluate the potential of this technology in the disposal of wastes from sewage treatment plants. PNL entered into a CRADA with Innotek to build a bench-scale demonstration reactor and test the system to advance the economic feasibility of a variety of high pressure chemical processes. Hydrothermal processing of corrosive substances on a large scale can now be made significantly safer and more economical through use of the DSPBV. Hydrothermal chemical reactions such as wet-air oxidation and supercritical water oxidation occur in a highly corrosive environment inside a pressure vessel. Average corrosion rates from 23 to 80 miles per year have been reported by Rice (1994) and Latanision (1993)

  20. A microcatalytic flow reactor for the study of heterogeneous catalytic reactions at elevated pressures

    Energy Technology Data Exchange (ETDEWEB)

    Belyi, A S; Fomichev, Yu V; Duplyakin, V K; Alfeev, V S

    1977-07-01

    A microcatalytic flow reactor for the study of heterogeneous catalytic reactions at elevated pressures (i.e., up to 40 atm) and nearly isothermal conditions up to 600/sup 0/C was designed for the conversion of small quantities of petrochemical feeds or feed mixtures at uniform, controllable flow rates of 0.5-5.0 cc/hr, for direct gas-chromatographic analysis of product samples at the reactor outlet, and for continuous monitoring of the degree of conversion in processes that evolve or absorb hydrogen. The device includes a feed injection system with a unique sealing feature that ensures a constant flow of liquid from a feed buret under positive displacement by a counterweight piston at very low rates into a tubular reactor of the perfect mixing type, a highly efficient vaporizer-mixer, and a two-channel sampler leading to the chromatograph. The apparatus has proved reliable, accurate, and convenient in two years of regular use. Diagrams.

  1. Temporal evolution of intraocular pressure elevation after pupillary dilation in pigment dispersion syndrome.

    Science.gov (United States)

    Jewelewicz, Daniel A; Radcliffe, Nathan M; Liebmann, Jeffrey; Ritch, Robert

    2009-03-01

    To report 4 patients with pigment dispersion syndrome (PDS) who had delayed intraocular pressure (IOP) spikes after pharmacologic pupillary dilation. Four patients with a diagnosis of PDS with documented IOP spike after pharmacologic pupillary dilation were included. Study patients were examined before and after pupillary dilation. The amount of pigment present in the anterior chamber and the IOP were measured at hourly intervals. Although maximal pigment liberation occurred immediately after maximal dilation, the IOP continued to elevate for at least 1.5 hours. The increase in IOP after pupillary dilation may not occur simultaneously with maximal pigment liberation but may follow it after the pigment has settled out of the anterior chamber. This has implications for monitoring patients with PDS after dilation to detect and treat rises in IOP.

  2. Effects of Weather and Heliophysical Conditions on Emergency Ambulance Calls for Elevated Arterial Blood Pressure

    Directory of Open Access Journals (Sweden)

    Jone Vencloviene

    2015-02-01

    Full Text Available We hypothesized that weather and space weather conditions were associated with the exacerbation of essential hypertension. The study was conducted during 2009–2010 in the city of Kaunas, Lithuania. We analyzed 13,475 cards from emergency ambulance calls (EACs, in which the conditions for the emergency calls were made coded I.10–I.15. The Kaunas Weather Station provided daily records of air temperature (T, wind speed (WS, relative humidity, and barometric pressure (BP. We evaluated the associations between daily weather variables and daily number of EACs by applying a multivariate Poisson regression. Unfavorable heliophysical conditions (two days after the active-stormy geomagnetic field or the days with solar WS > 600 km/s increased the daily number of elevated arterial blood pressure (EABP by 12% (RR = 1.12; 95% confidence interval (CI 1.04–1.21; and WS ≥ 3.5 knots during days of T < 1.5 °C and T ≥ 12.5 °C by 8% (RR = 1.08; CI 1.04–1.12. An increase of T by 10 °C and an elevation of BP two days after by 10 hPa were associated with a decrease in RR by 3%. An additional effect of T was detected during days of T ≥ 17.5 °C only in females. Women and patients with grade III arterial hypertension at the time of the ambulance call were more sensitive to weather conditions. These results may help in the understanding of the population’s sensitivity to different weather conditions.

  3. Obese children and adolescents have elevated nighttime blood pressure independent of insulin resistance and arterial stiffness

    DEFF Research Database (Denmark)

    Hvidt, Kristian N; Olsen, Michael H; Holm, Jens-Christian

    2014-01-01

    BACKGROUND: Insulin resistance has been related to elevated blood pressure (BP) in obese children and may adversely affect the vasculature by arterial stiffening. The objective was to investigate whether daytime and nighttime BP were elevated and related to insulin resistance and arterial stiffness...... in obese children and adolescents. METHODS: Ninety-two obese patients aged 10-18 years were compared with 49 healthy control individuals. Insulin resistance was measured as the homeostatic assessment model (HOMA), and arterial stiffness was measured as carotid-femoral pulse wave velocity (cfPWV). RESULTS......: Mean ± SD daytime systolic BP (SBP) (obese: 125±8.3mm Hg; control: 121±10.1mm Hg; P = 0.03) and nighttime SBP (obese: 108±10.7mm Hg; control: 102±8.2mm Hg; P = 0.0001) were higher in the obese group when compared with the control group. No difference was found in daytime diastolic BP (DBP), whereas...

  4. Mechanisms of sympathetic activation and blood pressure elevation by intermittent hypoxia.

    Science.gov (United States)

    Prabhakar, Nanduri R; Kumar, Ganesh K

    2010-11-30

    Sleep disordered breathing with recurrent apneas is one of the most frequently encountered breathing disorder in adult humans and preterm infants. Recurrent apnea patients exhibit several co-morbidities including hypertension and persistent sympathetic activation. Intermittent hypoxia (IH) resulting from apneas appears to be the primary stimulus for evoking autonomic changes. The purpose of this article is to briefly review the effects of IH on chemo- and baro-reflexes and circulating vasoactive hormones and their contribution to sympathetic activation and blood pressures. Sleep apnea patients and IH-treated rodents exhibit exaggerated arterial chemo-reflex. Studies on rodent models demonstrated that IH leads to hyperactive carotid body response to hypoxia. On the other hand, baro-reflex function is attenuated in patients with sleep apnea and in IH-treated rodents. Circulating vasoactive hormone levels are elevated in sleep apnea patients and in rodent models of IH. Thus, persistent sympathetic activation and hypertension associated with sleep apneas seems to be due to a combination of altered chemo- and baro-reflexes resulting in sympathetic activation and action of elevated circulating levels of vasoactive hormones on vasculature. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Tobacco smoking strengthens the association of elevated blood pressure with arterial stiffness: the Bogalusa Heart Study.

    Science.gov (United States)

    Yun, Miaoying; Li, Shengxu; Sun, Dianjianyi; Ge, Shaoqing; Lai, Chin-Chih; Fernandez, Camilo; Chen, Wei; Srinivasan, Sathanur R; Berenson, Gerald S

    2015-02-01

    The study assessed the hypothesis that smoking strengthens the association of adult arterial stiffness with long-term cumulative burden of blood pressure (BP) from childhood to adulthood. Tobacco smoking and elevated BPs are important risk factors of vascular stiffness. However, the synergistic effect of these two risk factors is not well established, especially for the long-term burden of elevated BP since childhood. The study cohort consisted of 945 adults (661 whites and 284 blacks, aged 24-43 years) who have BP measured 4-15 times since childhood (aged 4-17 years) in Bogalusa, Louisiana. The adult arterial stiffness was measured as aorta-femoral pulse wave velocity (afPWV); the total area under the curve (AUC) and incremental AUC were used as a measure of long-term burden and trends of BP, respectively. Increased adult afPWV was significantly associated with higher adulthood (P AUC (P AUC (P AUC (P = 0.007) were significantly greater among the current smokers than among the nonsmokers. DBP showed a similar pattern regarding the smoking-BP interaction on afPWV. These results, by showing the synergistic effect of tobacco smoking and long-term BP measures from childhood to adulthood on arterial stiffening process, underscore the importance of undertaking preventive strategies early in life and smoking behavior control.

  6. The elevated temperature and thermal shock fracture toughnesses of nuclear pressure vessel steel

    International Nuclear Information System (INIS)

    Hirano, Kazumi; Kobayashi, Hideo; Nakazawa, Hajime; Nara, Atsushi.

    1979-01-01

    Thermal shock experiments were conducted on nuclear pressure vessel steel A533 Grade B Class 1. Elastic-plastic fracture toughness tests were carried out within the same high temperature range of the thermal shock experiment and the relation between stretched zone width, SZW and J-integral was clarified. An elastic-plastic thermal shock fracture toughness value. J sub(tsc) was evaluated from a critical value of stretched zone width, SZW sub(tsc) at the initiation of thermal shock fracture by using the relation between SZW and J. The J sub(tsc) value was compared with elastic-plastic fracture toughness values, J sub( ic), and the difference between the J sub(tsc) and J sub( ic) values was discussed. The results obtained are summarized as follows; (1) The relation between SZW and J before the initiation of stable crack growth in fracture toughness test at a high temperature can be expressed by the following equation regardless of test temperature, SZW = 95(J/E), where E is Young's modulus. (2) Elevated temperature fracture toughness values ranging from room temperature to 400 0 C are nearly constant regardless of test temperature. It is confirmed that upper shelf fracture toughness exists. (3) Thermal shock fracture toughness is smaller than elevated temperature fracture toughness within the same high temperature range of thermal shock experiment. (author)

  7. Sources of radioiodine at pressurized water reactors. Final report

    International Nuclear Information System (INIS)

    Pelletier, C.A.; Cline, J.E.; Barefoot, E.D.; Hemphill, R.T.; Voilleque, P.G.; Emel, W.A.

    1978-11-01

    The report determines specific components and operations at operating pressurized water reactors that have a potential for being significant emission sources of radioactive iodine. The relative magnitudes of these specific sources in terms of the chemical forms of the radioiodine and the resultant annual averages from major components are established. The data are generalized for broad industry use for predictive purposes. The conclusions of this study indicate that the majority of radioiodine emanating from the primary side of pressurized water reactors comes from a few major areas; in some cases these sources are locally treatable; the interaction of radioiodine with plant interior surfaces is an important phenomenon mediating the source and affecting its release to the atmosphere; the chemical form varies depending on the circumstances of the release

  8. Effects of weather and heliophysical conditions on emergency ambulance calls for elevated arterial blood pressure.

    Science.gov (United States)

    Vencloviene, Jone; Babarskiene, Ruta M; Dobozinskas, Paulius; Sakalyte, Gintare; Lopatiene, Kristina; Mikelionis, Nerijus

    2015-02-27

    We hypothesized that weather and space weather conditions were associated with the exacerbation of essential hypertension. The study was conducted during 2009-2010 in the city of Kaunas, Lithuania. We analyzed 13,475 cards from emergency ambulance calls (EACs), in which the conditions for the emergency calls were made coded I.10-I.15. The Kaunas Weather Station provided daily records of air temperature (T), wind speed (WS), relative humidity, and barometric pressure (BP). We evaluated the associations between daily weather variables and daily number of EACs by applying a multivariate Poisson regression. Unfavorable heliophysical conditions (two days after the active-stormy geomagnetic field or the days with solar WS>600 km/s) increased the daily number of elevated arterial blood pressure (EABP) by 12% (RR=1.12; 95% confidence interval (CI) 1.04-1.21); and WS≥3.5 knots during days of Tweather conditions. These results may help in the understanding of the population's sensitivity to different weather conditions.

  9. Effects of gap and elevated pressure on ethanol reforming in a non-thermal plasma reactor

    International Nuclear Information System (INIS)

    Hoang, Trung Q; Zhu Xinli; Lobban, Lance L; Mallinson, Richard G

    2011-01-01

    Production of hydrogen for fuel cell vehicles, mobile power generators and for hydrogen-enhanced combustion from ethanol is demonstrated using energy-efficient non-thermal plasma reforming. A tubular reactor with a multipoint electrode system operated in pulsed mode was used. Complete conversion can be achieved with high selectivity (based on ethanol) of H 2 and CO of 111% and 78%, respectively, at atmospheric pressure. An elevated pressure of 15 psig shows improvement of selectivity of H 2 and CO to 120% and 87%, with a significant reduction of C 2 H x side products. H 2 selectivity increased to 127% when a high ratio (29.2) of water-to-ethanol feed was used. Increasing CO 2 selectivity is observed at higher water-to-ethanol ratios indicating that the water gas shift reaction occurs. A higher productivity and lower C 2 H x products were observed at larger gas gaps. The highest overall energy efficiency achieved, including electrical power consumption, was 82% for all products or 66% for H 2 only.

  10. Experimental strength evaluation of cylinders with a flat head subjected to internal pressure at elevated temperature

    International Nuclear Information System (INIS)

    Suzuki, Mitsuru; Makino, Yutaka

    1978-01-01

    The experiments using component test models such as a cylinder with a flat head and F.E.M. elastic analyses to investigate the secondary stress, peak stress and creep-fatigue interaction effect are described. The comparison of uniaxial stress with multiaxial stress about deformation and strength at elevated temperatures are also described here. The results of experiments and analysis are summarized as follows: (1) The maximum stress as the equivalent stress is the most suitable for the prediction of the creep failure life of cylinders subjected to internal pressure using the uniaxial creep test results. And the Mises's equivalent stress is the suitable for this prediction using the data of the onset of the uniaxial tertiary creep. (2) In the creep characteristics of the cylinder there, is no tertiary creep stage, and the rupture elongation of the cylinder accords with the elongation of the onset of the uniaxial tertiary creep. (3) It was recognized that the secondary stress occurred at the corner of the cylinder with a flat head has a little effect on creep and creep-fatigue life. (4) The life reduction effect due to the creep-fatigue interaction around the corner was recognized by the linear damage rule and compared with the value of Code Case 1592. (5) A difference of failure modes by imposed conditions for vessel with the size-discontinuity section was recognized by the cyclic internal pressure tests with hold time. (author)

  11. Fabrication of toroidal composite pressure vessels. Final report

    International Nuclear Information System (INIS)

    Dodge, W.G.; Escalona, A.

    1996-01-01

    A method for fabricating composite pressure vessels having toroidal geometry was evaluated. Eight units were fabricated using fibrous graphite material wrapped over a thin-walled aluminum liner. The material was wrapped using a machine designed for wrapping, the graphite material was impregnated with an epoxy resin that was subsequently thermally cured. The units were fabricated using various winding patterns. They were hydrostatically tested to determine their performance. The method of fabrication was demonstrated. However, the improvement in performance to weight ratio over that obtainable by an all metal vessel probably does not justify the extra cost of fabrication

  12. The effect of pressurization path on high pressure gas forming of Ti-3Al-2.5V at elevated temperature

    OpenAIRE

    Liu Gang; Wang Jianlong; Dang Kexin; Yuan Shijian

    2015-01-01

    High pressure gas forming is a tubular component forming technology with pressurized gas at elevated temperature, based on QPF, HMGF and Hydroforming. This process can be used to form tube blank at lower temperatures with high energy efficiency and also at higher strain rates. With Ti-3Al-2.5V Ti-alloy tube, the potential of HPGF was studied further through experiments at the elevated temperatures of 650 ∘C and 700 ∘C. In order to know the formability of the Ti-alloy tube, tensile tests were ...

  13. AIR SEPARATION BY PRESSURE SWING ADSORPTION USING SUPERIOR ADSORBENTS; FINAL

    International Nuclear Information System (INIS)

    Ralph T Yang

    2001-01-01

    Li-X zeolite (Si/Al= 1.0) is currently the best sorbent for use in the separation of air by adsorption processes. In particular, pressure swing adsorption (PSA) using zeolite sorbents is being increasingly used for air separation. Silver is also known to strongly affect the adsorptive properties of zeolites; and it is known that thermal vacuum dehydration of silver zeolites leads to the formation of silver clusters within the zeolite. In this work we have synthesized type X zeolites containing Ag and also varying mixtures of Li and Ag. In this project, we developed the Ag-containing zeolite as the best sorbent for air separation. We have also studied Co-ligand compounds as oxygen-selective sorbents. Syntheses, structural characterization and adsorption properties have been performed on all sorbents. The results are described in detail in 5 chapters

  14. Haploinsufficient Bmp4 ocular phenotypes include anterior segment dysgenesis with elevated intraocular pressure

    Directory of Open Access Journals (Sweden)

    Nusinowitz Steven

    2001-11-01

    Full Text Available Abstract Background Glaucoma is a blinding disease usually associated with high intraocular pressure (IOP. In some families, abnormal anterior segment development contributes to glaucoma. The genes causing anterior segment dysgenesis and glaucoma in most of these families are not identified and the affected developmental processes are poorly understood. Bone morphogenetic proteins (BMPs participate in various developmental processes. We tested the importance of Bmp4 gene dosage for ocular development and developmental glaucoma. Results Bmp4+/- mice have anterior segment abnormalities including malformed, absent or blocked trabecular meshwork and Schlemm's canal drainage structures. Mice with severe drainage structure abnormalities, over 80% or more of their angle's extent, have elevated IOP. The penetrance and severity of abnormalities is strongly influenced by genetic background, being most severe on the C57BL/6J background and absent on some other backgrounds. On the C57BL/6J background there is also persistence of the hyaloid vasculature, diminished numbers of inner retinal cells, and absence of the optic nerve. Conclusions We demonstrate that heterozygous deficiency of BMP4 results in anterior segment dysgenesis and elevated IOP. The abnormalities are similar to those in human patients with developmental glaucoma. Thus, BMP4 is a strong candidate to contribute to Axenfeld-Rieger anomaly and other developmental conditions associated with human glaucoma. BMP4 also participates in posterior segment development and wild-type levels are usually critical for optic nerve development on the C57BL/6J background. Bmp4+/- mice are useful for studying various components of ocular development, and may allow identification of strain specific modifiers affecting a variety of ocular phenotypes.

  15. Elevated pressure, a novel cancer therapeutic tool for sensitizing cisplatin-mediated apoptosis in A549

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sangnam [Cellular and Developmental Biology, Division of Biomedical Science, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Department of Preventive Medicine and Medical Research Center for Environmental Toxico-Genomics and Proteomics, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kim, Yanghee [Department of Preventive Medicine and Medical Research Center for Environmental Toxico-Genomics and Proteomics, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kim, Joonhee [Cellular and Developmental Biology, Division of Biomedical Science, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Department of Preventive Medicine and Medical Research Center for Environmental Toxico-Genomics and Proteomics, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kwon, Daeho [Department of Preventive Medicine and Medical Research Center for Environmental Toxico-Genomics and Proteomics, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Lee, Eunil, E-mail: eunil@korea.ac.kr [Cellular and Developmental Biology, Division of Biomedical Science, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Department of Preventive Medicine and Medical Research Center for Environmental Toxico-Genomics and Proteomics, College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of)

    2010-08-13

    Research highlights: {yields} Sensitized apoptosis in cancer cells stimulated by EP precondition with p53 dependence. {yields} EP attenuates several CDDP-resistance mechanisms. {yields} No harmful effect of EP on normal fibroblasts. -- Abstract: Intensive cancer therapy strategies have thus far focused on sensitizing cancer cells to anticancer drug-mediated apoptosis to overcome drug resistance, and this strategy has led to more effective cancer therapeutics. Cisplatin (cis-diamminedichloroplatinum(II), CDDP) is an effective anticancer drug used to treat many types of cancer, including non-small cell lung carcinoma (NSCLC), and can be used in combination with various chemicals to enhance cancer cell apoptosis. Here, we introduce the use of elevated pressure (EP) in combination with CDDP for cancer treatment and explore the effects of EP on CDDP-mediated apoptosis in NSCLC cells. Our findings demonstrate that preconditioning NSCLC cells with EP sensitizes cells for CDDP-induced apoptosis. Enhanced apoptosis was dependent on p53 and HO-1 expression, and was associated with increased DNA damage and down-regulation of genes involved in nucleotide excision repair. The transcriptional levels of transporter proteins indicated that the mechanism by which EP-induced CDDP sensitization was intracellular drug accumulation. The protein levels of some antioxidants, such as hemeoxygenase-1 (HO-1), glutathione (GSH) and glutathione peroxidase (Gpx), were decreased in A549 cells exposed to EP via the down-regulation of the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). Furthermore, normal human fibroblasts were resistant to EP treatment, with no elevated DNA damage or apoptosis. Collectively, these data show that administration of EP is a potential adjuvant tool for CDDP-based chemosensitivity of lung cancer cells that may reduce drug resistance.

  16. Appropriateness of Bolus Antihypertensive Therapy for Elevated Blood Pressure in the Emergency Department.

    Science.gov (United States)

    Miller, Joseph B; Arter, Andrew; Wilson, Suprat S; Janke, Alexander T; Brody, Aaron; Reed, Brian P; Levy, Phillip D

    2017-08-01

    While moderate to severely elevated blood pressure (BP) is present in nearly half of all emergency department (ED) patients, the incidence of true hypertensive emergencies in ED patients is low. Administration of bolus intravenous (IV) antihypertensive treatment to lower BP in patients without a true hypertensive emergency is a wasteful practice that is discouraged by hypertension experts; however, anecdotal evidence suggests this occurs with relatively high frequency. Accordingly, we sought to assess the frequency of inappropriate IV antihypertensive treatment in ED patients with elevated BP absent a hypertensive emergency. We performed a retrospective cohort study from a single, urban, teaching hospital. Using pharmacy records, we identified patients age 18-89 who received IV antihypertensive treatment in the ED. We defined treatment as inappropriate if documented suspicion for an indicated cardiovascular condition or acute end-organ injury was lacking. Data abstraction included adverse events and 30-day readmission rates, and analysis was primarily descriptive. We included a total of 357 patients over an 18-month period. The mean age was 55; 51% were male and 93% black, and 127 (36.4%) were considered inappropriately treated. Overall, labetalol (61%) was the most commonly used medication, followed by enalaprilat (18%), hydralazine (18%), and metoprolol (3%). There were no significant differences between appropriate and inappropriate BP treatment groups in terms of clinical characteristics or adverse events. Hypotension or bradycardia occurred in three (2%) patients in the inappropriate treatment cohort and in two (1%) patients in the appropriately treated cohort. Survival to discharge and 30-day ED revisit rates were equivalent. More than one in three patients who were given IV bolus antihypertensive treatment in the ED received such therapy inappropriately by our definition, suggesting that significant resources could perhaps be saved through education of

  17. Appropriateness of Bolus Antihypertensive Therapy for Elevated Blood Pressure in the Emergency Department

    Directory of Open Access Journals (Sweden)

    Joseph B. Miller

    2017-07-01

    Full Text Available Introduction: While moderate to severely elevated blood pressure (BP is present in nearly half of all emergency department (ED patients, the incidence of true hypertensive emergencies in ED patients is low. Administration of bolus intravenous (IV antihypertensive treatment to lower BP in patients without a true hypertensive emergency is a wasteful practice that is discouraged by hypertension experts; however, anecdotal evidence suggests this occurs with relatively high frequency. Accordingly, we sought to assess the frequency of inappropriate IV antihypertensive treatment in ED patients with elevated BP absent a hypertensive emergency. Methods: We performed a retrospective cohort study from a single, urban, teaching hospital. Using pharmacy records, we identified patients age 18–89 who received IV antihypertensive treatment in the ED. We defined treatment as inappropriate if documented suspicion for an indicated cardiovascular condition or acute end-organ injury was lacking. Data abstraction included adverse events and 30-day readmission rates, and analysis was primarily descriptive. Results: We included a total of 357 patients over an 18-month period. The mean age was 55; 51% were male and 93% black, and 127 (36.4% were considered inappropriately treated. Overall, labetalol (61% was the most commonly used medication, followed by enalaprilat (18%, hydralazine (18%, and metoprolol (3%. There were no significant differences between appropriate and inappropriate BP treatment groups in terms of clinical characteristics or adverse events. Hypotension or bradycardia occurred in three (2% patients in the inappropriate treatment cohort and in two (1% patients in the appropriately treated cohort. Survival to discharge and 30-day ED revisit rates were equivalent. Conclusion: More than one in three patients who were given IV bolus antihypertensive treatment in the ED received such therapy inappropriately by our definition, suggesting that significant

  18. Elevated pressure, a novel cancer therapeutic tool for sensitizing cisplatin-mediated apoptosis in A549

    International Nuclear Information System (INIS)

    Oh, Sangnam; Kim, Yanghee; Kim, Joonhee; Kwon, Daeho; Lee, Eunil

    2010-01-01

    Research highlights: → Sensitized apoptosis in cancer cells stimulated by EP precondition with p53 dependence. → EP attenuates several CDDP-resistance mechanisms. → No harmful effect of EP on normal fibroblasts. -- Abstract: Intensive cancer therapy strategies have thus far focused on sensitizing cancer cells to anticancer drug-mediated apoptosis to overcome drug resistance, and this strategy has led to more effective cancer therapeutics. Cisplatin (cis-diamminedichloroplatinum(II), CDDP) is an effective anticancer drug used to treat many types of cancer, including non-small cell lung carcinoma (NSCLC), and can be used in combination with various chemicals to enhance cancer cell apoptosis. Here, we introduce the use of elevated pressure (EP) in combination with CDDP for cancer treatment and explore the effects of EP on CDDP-mediated apoptosis in NSCLC cells. Our findings demonstrate that preconditioning NSCLC cells with EP sensitizes cells for CDDP-induced apoptosis. Enhanced apoptosis was dependent on p53 and HO-1 expression, and was associated with increased DNA damage and down-regulation of genes involved in nucleotide excision repair. The transcriptional levels of transporter proteins indicated that the mechanism by which EP-induced CDDP sensitization was intracellular drug accumulation. The protein levels of some antioxidants, such as hemeoxygenase-1 (HO-1), glutathione (GSH) and glutathione peroxidase (Gpx), were decreased in A549 cells exposed to EP via the down-regulation of the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). Furthermore, normal human fibroblasts were resistant to EP treatment, with no elevated DNA damage or apoptosis. Collectively, these data show that administration of EP is a potential adjuvant tool for CDDP-based chemosensitivity of lung cancer cells that may reduce drug resistance.

  19. Elevated pressure improves the extraction and identification of proteins recovered from formalin-fixed, paraffin-embedded tissue surrogates.

    Directory of Open Access Journals (Sweden)

    Carol B Fowler

    2010-12-01

    Full Text Available Proteomic studies of formalin-fixed paraffin-embedded (FFPE tissues are frustrated by the inability to extract proteins from archival tissue in a form suitable for analysis by 2-D gel electrophoresis or mass spectrometry. This inability arises from the difficulty of reversing formaldehyde-induced protein adducts and cross-links within FFPE tissues. We previously reported the use of elevated hydrostatic pressure as a method for efficient protein recovery from a hen egg-white lysozyme tissue surrogate, a model system developed to study formalin fixation and histochemical processing.In this study, we demonstrate the utility of elevated hydrostatic pressure as a method for efficient protein recovery from FFPE mouse liver tissue and a complex multi-protein FFPE tissue surrogate comprised of hen egg-white lysozyme, bovine carbonic anhydrase, bovine ribonuclease A, bovine serum albumin, and equine myoglobin (55∶15∶15∶10∶5 wt%. Mass spectrometry of the FFPE tissue surrogates retrieved under elevated pressure showed that both the low and high-abundance proteins were identified with sequence coverage comparable to that of the surrogate mixture prior to formaldehyde treatment. In contrast, non-pressure-extracted tissue surrogate samples yielded few positive and many false peptide identifications. Studies with soluble formalin-treated bovine ribonuclease A demonstrated that pressure modestly inhibited the rate of reversal (hydrolysis of formaldehyde-induced protein cross-links. Dynamic light scattering studies suggest that elevated hydrostatic pressure and heat facilitate the recovery of proteins free of formaldehyde adducts and cross-links by promoting protein unfolding and hydration with a concomitant reduction in the average size of the protein aggregates.These studies demonstrate that elevated hydrostatic pressure treatment is a promising approach for improving the recovery of proteins from FFPE tissues in a form suitable for proteomic analysis.

  20. Elevated Pressure Improves the Extraction and Identification of Proteins Recovered from Formalin-Fixed, Paraffin-Embedded Tissue Surrogates

    Science.gov (United States)

    Fowler, Carol B.; Chesnick, Ingrid E.; Moore, Cedric D.; O'Leary, Timothy J.; Mason, Jeffrey T.

    2010-01-01

    Background Proteomic studies of formalin-fixed paraffin-embedded (FFPE) tissues are frustrated by the inability to extract proteins from archival tissue in a form suitable for analysis by 2-D gel electrophoresis or mass spectrometry. This inability arises from the difficulty of reversing formaldehyde-induced protein adducts and cross-links within FFPE tissues. We previously reported the use of elevated hydrostatic pressure as a method for efficient protein recovery from a hen egg-white lysozyme tissue surrogate, a model system developed to study formalin fixation and histochemical processing. Principal Findings In this study, we demonstrate the utility of elevated hydrostatic pressure as a method for efficient protein recovery from FFPE mouse liver tissue and a complex multi-protein FFPE tissue surrogate comprised of hen egg-white lysozyme, bovine carbonic anhydrase, bovine ribonuclease A, bovine serum albumin, and equine myoglobin (55∶15∶15∶10∶5 wt%). Mass spectrometry of the FFPE tissue surrogates retrieved under elevated pressure showed that both the low and high-abundance proteins were identified with sequence coverage comparable to that of the surrogate mixture prior to formaldehyde treatment. In contrast, non-pressure-extracted tissue surrogate samples yielded few positive and many false peptide identifications. Studies with soluble formalin-treated bovine ribonuclease A demonstrated that pressure modestly inhibited the rate of reversal (hydrolysis) of formaldehyde-induced protein cross-links. Dynamic light scattering studies suggest that elevated hydrostatic pressure and heat facilitate the recovery of proteins free of formaldehyde adducts and cross-links by promoting protein unfolding and hydration with a concomitant reduction in the average size of the protein aggregates. Conclusions These studies demonstrate that elevated hydrostatic pressure treatment is a promising approach for improving the recovery of proteins from FFPE tissues in a form

  1. Elevated blood pressure and its predictors among secondary school students in Sarawak: a cross-sectional study.

    Science.gov (United States)

    Grace Kho, Woei Feng; Cheah, Whye Lian; Hazmi, Helmy

    2018-03-01

    Hypertension is a health issue affecting adolescents. Accumulating evidence affirms that elevated blood pressure begins in childhood and tracks into adulthood. This cross-sectional study was conducted to determine the prevalence of elevated blood pressure and its predictors among secondary school students in Sarawak, Malaysia. A total of 2,461 secondary school students aged 12-17 years from 19 schools in Sarawak participated in the study. Questionnaire was used to obtain socio-demographic data, parental history of hypertension, and self-reported physical activity. Anthropometric and blood pressure measurements were taken. Data was entered and analysed using SPSS version 23.0. The prevalence of adolescents with elevated blood pressure, overweight, central obesity, and overfat were 30.1%, 24.3%, 13.5%, and 6.7%, respectively. Multivariate logistic regression demonstrated the predictors significantly associated with elevated blood pressure among respondents: overweight (adjusted odds ratio=3.144), being male (adjusted odds ratio=3.073), being Chinese (adjusted odds ratio=2.321) or Iban (adjusted odds ratio=1.578), central obesity (adjusted odds ratio=2.145), being overfat (adjusted odds ratio=1.885), and being an older adolescent (adjusted odds ratio=1.109). Parental history of hypertension, locality, and physical activity showed no significant associations. The obesity epidemic must be tackled at community and school levels by health education and regulation of school canteen foods. Copyright© by the National Institute of Public Health, Prague 2018.

  2. Medical Devices; Obstetrical and Gynecological Devices; Classification of the Fetal Head Elevator. Final order.

    Science.gov (United States)

    2017-12-19

    The Food and Drug Administration (FDA or we) is classifying the fetal head elevator into class II (special controls). The special controls that apply to the device type are identified in this order and will be part of the codified language for the fetal head elevator's classification. We are taking this action because we have determined that classifying the device into class II (special controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.

  3. The effects and regulatory mechanism of RIP3 on RGC-5 necroptosis following elevated hydrostatic pressure.

    Science.gov (United States)

    Shang, Lei; Ding, Wei; Li, Na; Liao, Lvshuang; Chen, Dan; Huang, Jufang; Xiong, Kun

    2017-02-06

    Necroptosis is a type of regulated cell death that has been implicated in various diseases. Receptor-interacting protein 3 (RIP3), a member of the RIP family, is an important mediator of the necroptotic pathway. Cleavage of RIP3 at Asp328 by caspase-8 abolishes the kinase activity of RIP3, which is critical for necroptosis. Moreover, RIP3 is significantly upregulated during the early stages of acute high intra-ocular pressure and oxygen glucose deprivation. In this study, the effects of RIP3 during elevated hydrostatic pressure (EHP) were investigated and the possible mechanism through which caspase-8 regulated RIP3 cleavage was explored. Flow cytometry analysis revealed that the number of EHP-induced necrotic retinal ganglion cell 5 (RGC-5) cells was reduced after RIP3-knockdown. Furthermore, malondialdehyde (MDA) levels and glycogen phosphorylase (PYGL) activity in normal RGC-5 cells were much higher than those in RIP3-knockdown cells after EHP. EHP-induced RGC-5 necrosis was significantly reduced after treatment with butylated hydroxyanisole (BHA), a reactive oxygen species (ROS) scavenger. MDA levels and PYGL activity were lower in normal RGC-5 cells than those in cells with caspase-8 inhibition after EHP. Western blot analysis demonstrated that the RIP3 cleavage product was upregulated in cells with caspase-8 inhibition. Additionally, flow cytometry analysis revealed that the number of EHP-induced necrotic RGC-5 cells was increased after caspase-8 inhibition. Our results suggested that RGC-5 necroptosis following EHP was mediated by RIP3 through induction of PYGL activity and subsequent ROS accumulation. Thus, caspase-8 may participate in the regulation of RGC-5 necroptosis via RIP3 cleavage. © The Author 2016. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Grade III or Grade IV Hypertensive Retinopathy with Severely Elevated Blood Pressure

    Directory of Open Access Journals (Sweden)

    Amanda D Henderson

    2012-12-01

    Full Text Available Introduction: Hypertensive retinopathy describes a spectrum of retinal changes in patients with elevated blood pressure (BP. It is unknown why some patients are more likely to develop acute ocular end-organ damage than others with similar BP. We examined risk factors for grade III/IV hypertensive retinopathy among patients with hypertensive urgency in the emergency department (ED and compared healthcare utilization and mortality between patients with and without grade III/IV hypertensive retinopathy.Methods: A preplanned subanalysis of patients who presented to a university hospital ED with diastolic BP > 120 mmHg and who enrolled in the Fundus Photography versus Ophthalmoscopy Trial Outcomes in the ED study was performed. Bilateral nonmydriatic ocular fundus photographs, vital signs, and demographics were obtained at presentation. Past medical history, laboratory values, healthcare utilization, and mortality were ascertained from medical record review at least 8 months after initial ED visit.Results: Twenty-one patients with diastolic BP > 120 mmHg, 7 of whom (33% had grade III/IV hypertensive retinopathy, were included. Patients with retinopathy were significantly younger than those without (median 33 vs 50 years, P = 0.02. Mean arterial pressure (165 vs 163 mmHg was essentially equal in the 2 groups. Patients with retinopathy had substantially increased but nonsignificant rates of ED revisit (57% vs 29%, P = 0.35 and hospital admission after ED discharge (43% vs 14%, P = 0.28. One of the patients with retinopathy died, but none without.Conclusion: Younger patients may be at higher risk for grade III/IV hypertensive retinopathy among patients with hypertensive urgency. Chronic compensatory mechanisms may have not yet developed in these younger patients. Alternatively, older patients with retinopathy may be underrepresented secondary to increased mortality among these patients at a younger age (survivorship bias. Further research is needed to

  5. A Secure Automated Elevator Management System and Pressure Sensor based Floor Estimation for Indoor Mobile Robot Transportation

    Directory of Open Access Journals (Sweden)

    Ali Abduljalil Abdulla

    2017-08-01

    Full Text Available In this paper, a secure elevator handling system is presented to enable a flexible movement of wheeled mobile robots among laboratories distributed in different floors. The automated handling system consists mainly of an ADAM module which has the ability to call the elevator to the robot’s current floor and to request the destination floor. The LPS25HP pressure sensor attached to an STM32F411 microcontroller is utilized as a height measurement system to estimate the robot’s current floor inside the elevator. The ultrasonic sensor is used to recognize the elevator’s door status. Many challenges have to be solved to realize a stable height measurement system based on pressure sensor readings. The difference of the pressure sensor readings before and after soldering is realized by comparing the reading after soldering with an accurate barometric reading. In addition, the sensor output signal shows oscillation and wide variation of the same floor pressure sensor readings at different times. The oscillation in the output signal has been handled using a first order FIR smoothing filter. The first order filter was selected to balance between the stability and the elapsed time to receive the updated values. An auto-calibration stage is established to maintain the wide variation in the atmospheric pressure readings by calibrating the sensor readings with the robot’s current floor before entering the elevator. An error handling management system is utilized to guarantee a stable automated elevator management system performance. Many experiments to assess and verify the performance of the automated elevator management system and robot’s current floor estimation are reported. The experimental results show that the proposed methods and sub-systems developed for the mobile robot are effective and efficient in providing a transportation service in multiple-floor life sciences laboratories.

  6. Medical devices; exemption from premarket notification; class II devices; wheelchair elevator. Final order.

    Science.gov (United States)

    2013-03-04

    The Food and Drug Administration (FDA) is publishing an order granting a petition requesting exemption from premarket notification requirements for wheelchair elevator devices commonly known as inclined platform lifts and vertical platform lifts. These devices are used to provide a means for a person with a mobility impairment caused by injury or other disease to move from one level to another, usually in a wheelchair. This order exempts wheelchair elevators, class II devices, from premarket notification and establishes conditions for exemption for this device that will provide a reasonable assurance of the safety and effectiveness of the device without submission of a premarket notification (510(k)). This exemption from 510(k), subject to these conditions, is immediately in effect for wheelchair elevators. All other devices classified under FDA's wheelchair elevator regulations, including attendant-operated stair climbing devices for wheelchairs and portable platform lifts, continue to require submission of 510(k)s. FDA is publishing this order in accordance with the section of the Food, Drug, and Cosmetic Act (the FD&C Act) permitting the exemption of a device from the requirement to submit a 510(k).

  7. Effects of arm elevation on radial artery pressure: a new method to distinguish hypovolemic shock and septic shock from hypotension.

    Science.gov (United States)

    Xie, Zhiyi; Zhang, Zhenyu; Xu, Yuan; Zhou, Hua; Wu, Sheng; Wang, Zhong

    2018-06-01

    In this prospective observational study, we investigated the variability in radial artery invasive blood pressure associated with arm elevation in patients with different hemodynamic types. We carried out a prospective observational study using data from 73 general anesthesia hepatobiliary postoperative adult patients admitted to an ICU over a 1-year period. A standard procedure was used for the arm elevation test. The value of invasive radial arterial pressure was recorded at baseline, and 30 and 60 s after the arm had been raised from 0° to 90°. We compared the blood pressure before versus after arm elevation, and between hemodynamically stable, hypovolemic shock, and septic shock patient groups. In all 73 patients, systolic arterial pressure (SAP) decreased, diastolic arterial pressure (DAP) increased, and pulse pressure (PP) decreased at 30 and 60 s after arm elevation (Ppressure (MAP) was unchanged (P>0.05). On comparing 30 and 60 s, there was no significant difference in SAP, DAP, PP, or MAP (P>0.05). In 40 hemodynamically stable patients, SAP and PP decreased, and DAP and MAP increased significantly at 30 and 60 s after arm elevation compared with baseline (P0.05). In 17 patients with septic shock, SAP, PP, and MAP decreased significantly versus baseline at 30 and 60 s (P0.05). Comparison of the absolute value of pressure change of septic shock patients at 30 s after raising the arm showed that SAP, DAP, and MAP changes were significantly lower compared with those in hypovolemic shock and hemodynamically stable patients (Parm elevation of SAP. The best cut-off point for the SAP change value was -5 mmHg or less, with a sensitivity of 94.12%, a specificity of 80.36%, a positive likelihood ratio of 4.79 (95% CI: 2.8-8.2), and a negative likelihood ratio of 0.073 (95% CI: 0.01-0.5). Our study shows that hypovolemic shock and septic shock patients have significantly different radial artery invasive blood pressure changes in an arm elevation test

  8. Dry reforming of methane with CO{sub 2} at elevated pressures

    Energy Technology Data Exchange (ETDEWEB)

    Milanov, A.; Schwab, E.; Wasserschaff, G. [BASF SE, Ludwigshafen (Germany); Schunk, S. [hte AG, Heidelberg (Germany)

    2013-11-01

    The indirect conversion of natural gas into higher value chemicals and fuels via syngas is superior with regard to efficiency compared to the currently available direct conversion technologies and remains the industrially preferred route. Typically the syngas production route is generally dictated by the H{sub 2}/CO ratio requirements of the downstream synthesis process. Processes such as direct DME synthesis, high-temperature Fischer-Tropsch and acetic acid synthesis require CO rich syngas that is not readily accessible by established technologies like steam methane reforming (SMR) and autothermal reforming of methane (ATR). The CO{sub 2} reforming of methane, also known as dry reforming (DRM), is an attractive alternative technology for the production of CO-rich syngas. This paper gives an overview of the current joint research activities at BASF and hte AG aiming to develop suitable catalysts for CO{sub 2} reforming of methane at elevated pressures with minimized input of process steam. The performance profiles of two newly developed base metal catalysts are presented and discussed. The catalysts exhibit high degrees of methane and CO{sub 2} conversion in combination with an extraordinary coking resistance under high severity process conditions. (orig.)

  9. Association of "Elevated Blood Pressure" and "Stage 1 Hypertension" With Cardiovascular Mortality Among an Asian Population.

    Science.gov (United States)

    Talaei, Mohammad; Hosseini, Naeimeh; Koh, Angela S; Yuan, Jian-Min; Koh, Woon-Puay

    2018-04-10

    The new American College of Cardiology/American Heart Association high blood pressure (BP) guidelines in the United States have lowered definition of hypertension by defining normal as systolic/diastolic BP hypertension as systolic between 130 and 139 mm Hg or diastolic between 80 and 89 mm Hg. We investigated the association between the new hypertension definition and cardiovascular disease mortality among Chinese in Singapore. We used data from 30 636 participants of a population-based cohort, the SCHS (Singapore Chinese Health Study), who had BPs measured using a standard protocol at ages 46 to 85 years between 1994 and 2005. Information on lifestyle factors was collected at recruitment (1993-1998) and follow-up 1 interviews (1999 and 2004). Mortality was identified via nationwide registry linkage up to December 31, 2016. Neither elevated BP (hazard ratio, 0.89; 95% confidence interval, 0.74-1.07) nor stage 1 hypertension (hazard ratio, 0.94; 95% confidence interval, 0.81-1.11) was associated with increased risk of cardiovascular mortality compared with normal BP in the whole cohort. Stage 1 hypertension was associated with increased cardiovascular risk only in those hypertension may not be associated with increased cardiovascular mortality across all ages among Chinese in Singapore, but that the at-risk subpopulation is limited to those <65 years of age and without a prior cardiovascular disease. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  10. One elevated bladder pressure measurement may not be enough to diagnose abdominal compartment syndrome.

    Science.gov (United States)

    Young, Andrew Joseph; Weber, William; Wolfe, Luke; Ivatury, Rao R; Duane, Therese Marie

    2013-02-01

    Bladder pressure measurements (BPMs) are considered a key component in the diagnosis of abdominal compartment syndrome (ACS). The purpose of this observational review was to determine risk factors of ACS and associated mortality with particular focus on the role of BPM. A retrospective trauma registry and chart review was performed on trauma patients from January 2003 through December 2010. Comparisons were made between patients with and without ACS. There were 3172 patients included in the study of whom 46 had ACS. Patients with ACS were younger, more severely injured, with longer lengths of stay. Logistic regression determined Injury Severity Score (ISS) and urinary catheter days as independent predictors of ACS, whereas independent predictors of mortality included age, ISS, and ACS. Subset analysis demonstrated no association between BPM 20 mmHg or greater and diagnosis of ACS versus no ACS. Logistic regression indicated independent predictors of mortality were number of BPM 20 mmHg or greater and age. Patients with ACS are more severely injured with worse outcomes. An isolated BPM 20 mmHg or greater was not associated with ACS and may be inadequate to independently diagnose ACS. These findings suggest the need for repeat measurements with early intervention if they remain elevated in an effort to decrease mortality associated with ACS.

  11. Blood pressure-to-height ratio as a screening indicator of elevated blood pressure among children and adolescents in Chongqing, China.

    Science.gov (United States)

    Wang, L Y; Liu, Q; Cheng, X T; Jiang, J J; Wang, H

    2017-07-01

    We aimed to evaluate the performance of blood pressure-to-height ratio (BPHR) and establish their optimal thresholds for elevated blood pressure (BP) among children aged 6 to 17 years in Chongqing, China. Data were collected from 11 029 children and adolescents aged 6-17 years in 12 schools in Chongqing according to multistage stratified cluster sampling method. The gold standard for elevated BP was defined as systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) ⩾95th percentile for gender, age and height. The diagnostic performance of systolic BPHR (SBPHR) and diastolic BPHR (DBPHR) to screen for elevated BP was evaluated through receiver-operating characteristic curves (including the area under the curve (AUC) and its 95% confidence interval, sensitivity and specificity). The prevalence of elevated BP in children and adolescents in Chongqing was 10.36% by SBP and/or DBP ⩾95th percentile for gender, age and height. The optimal thresholds of SBPHR/DBPHR for identifying elevated BP were 0.86/0.58 for boys and 0.85/0.57 for girls among children aged 6 to 8 years, 0.81/0.53 for boys and 0.80/0.52 for girls among children aged 9 to 11 years and 0.71/0.45 for boys and 0.72/0.47 for girls among adolescents aged 12-17 years, respectively. Across gender and the specified age groups, AUC ranged from 0.82 to 0.88, sensitivity were above 0.94 and the specificities were over 0.7. The positive predictive values ranged from 0.30 to 0.38 and the negative predictive values were ⩾0.99. BPHR, with uniform values across broad age groups (6-8, 9-11 and 12-17 years) for boys and for girls is a simple indicator to screen elevated BP in children and adolescents in Chongqing.

  12. ATR-IR spectroscopic cell for in situ studies at solid-liquid interface at elevated temperatures and pressures

    NARCIS (Netherlands)

    Koichumanova, Kamila; Visan, Aura; Geerdink, Bert; Lammertink, Rob G.H.; Mojet, Barbara; Seshan, Kulathuiyer; Lefferts, Leonardus

    2017-01-01

    An in situ ATR-IR spectroscopic cell suitable for studies at solid-liquid interface is described including the design and experimental details in continuous flow mode at elevated temperatures (230 °C) and pressures (30 bar). The design parameters considered include the cell geometry, the procedure

  13. Systems genetics identifies a role for Cacna2d1 regulation in elevated intraocular pressure and glaucoma susceptibility

    NARCIS (Netherlands)

    Chintalapudi, S.R. (Sumana R.); Maria, D. (Doaa); Di Wang, X. (Xiang); Bailey, J.N.C. (Jessica N. Cooke); Allingham, R. (Rand); M.H. Brilliant (Murray H.); D.L. Budenz (Donald L.); J. Fingert (John); D. Gaasterland (Douglas); T. Gaasterland (Terry); J.L. Haines (Jonathan); Hark, L. (Lisa); M.A. Hauser (Michael); R.P. Igo Jr. (Robert); Hee Kang, J. (Jae); P. Kraft (Peter); R.K. Lee (Richard K.); P.A. Lichter (Paul A.); Liu, Y. (Yutao); Moroi, S. (Syoko); L.R. Pasquale (Louis); M.A. Pericak-Vance (Margaret); A. Realini (Anthony); Rhee, D. (Doug); Richards, J.R. (Julia R.); Ritch, R. (Robert); J.S. Schuman (Joel S.); W.K. Scott (William); K. Singh (Kuldev); A.J. Sit (Arthur J.); D. Vollrath (Douglas); G. Wollstein (Gadi); D.J. Zack (Donald); T. Aung (Tin); Bonnemaijer, P. (Peter); Cheng, C.-Y. (Cheng-Yu); J.E. Craig (Jamie); C.M. van Duijn (Cornelia); P. Gharahkhani (Puya); Iglesias Gonzalez, A. (Adriana); Hammond, C.J. (Christopher J.); Hewitt, A. (Alex); Hoehn, R. (Rene); Jonansson, F. (Fridbert); A.P. Khawaja (Anthony); Chuen Khor, C. (Chiea); C.C.W. Klaver (Caroline); A.J. Lotery (Andrew); D.A. Mackey (David); MacGregor, S. (Stuart); Pang, C. (Calvin); F. Pasutto (Francesca); J-A. Zwart (John-Anker); G. Thorleifsson (Gudmar); Thorsteinsdottir, U. (Unnar); V. Vitart (Veronique); E.N. Vithana (Eranga); T.L. Young (Terri L.); T. Zeller (Tanja); P.G. Hysi (Pirro); J.L. Wiggs (Janey L.); R.W. Williams (Robert W.); Jablonski, M.M. (Monica M.)

    2017-01-01

    textabstractGlaucoma is a multi-factorial blinding disease in which genetic factors play an important role. Elevated intraocular pressure is a highly heritable risk factor for primary open angle glaucoma and currently the only target for glaucoma therapy. Our study helps to better understand

  14. Apparatus and method for direct measurement of coal ash sintering and fusion properties at elevated temperatures and pressures

    Science.gov (United States)

    Khan, M. Rashid

    1990-01-01

    A high-pressure microdilatometer is provided for measuring the sintering and fusion properties of various coal ashes under the influence of elevated pressures and temperatures in various atmospheres. Electrical resistivity measurements across a sample of coal ash provide a measurement of the onset of the sintering and fusion of the ash particulates while the contraction of the sample during sintering is measured with a linear variable displacement transducer for detecting the initiation of sintering. These measurements of sintering in coal ash at different pressures provide a mechanism by which deleterious problems due to the sintering and fusion of ash in various combustion systems can be minimized or obviated.

  15. Effect of Soret diffusion on lean hydrogen/air flames at normal and elevated pressure and temperature

    KAUST Repository

    Zhou, Zhen; Hernandez Perez, Francisco; Shoshin, Yuriy; van Oijen, Jeroen A.; de Goey, Laurentius P.H.

    2017-01-01

    The influence of Soret diffusion on lean premixed flames propagating in hydrogen/air mixtures is numerically investigated with a detailed chemical and transport models at normal and elevated pressure and temperature. The Soret diffusion influence on the one-dimensional (1D) flame mass burning rate and two-dimensional (2D) flame propagating characteristics is analysed, revealing a strong dependency on flame stretch rate, pressure and temperature. For 1D flames, at normal pressure and temperature, with an increase of Karlovitz number from 0 to 0.4, the mass burning rate is first reduced and then enhanced by Soret diffusion of H2 while it is reduced by Soret diffusion of H. The influence of Soret diffusion of H2 is enhanced by pressure and reduced by temperature. On the contrary, the influence of Soret diffusion of H is reduced by pressure and enhanced by temperature. For 2D flames, at normal pressure and temperature, during the early phase of flame evolution, flames with Soret diffusion display more curved flame cells. Pressure enhances this effect, while temperature reduces it. The influence of Soret diffusion of H2 on the global consumption speed is enhanced at elevated pressure. The influence of Soret diffusion of H on the global consumption speed is enhanced at elevated temperature. The flame evolution is more affected by Soret diffusion in the early phase of propagation than in the long run due to the local enrichment of H2 caused by flame curvature effects. The present study provides new insights into the Soret diffusion effect on the characteristics of lean hydrogen/air flames at conditions that are relevant to practical applications, e.g. gas engines and turbines.

  16. Effect of Soret diffusion on lean hydrogen/air flames at normal and elevated pressure and temperature

    KAUST Repository

    Zhou, Zhen

    2017-04-12

    The influence of Soret diffusion on lean premixed flames propagating in hydrogen/air mixtures is numerically investigated with a detailed chemical and transport models at normal and elevated pressure and temperature. The Soret diffusion influence on the one-dimensional (1D) flame mass burning rate and two-dimensional (2D) flame propagating characteristics is analysed, revealing a strong dependency on flame stretch rate, pressure and temperature. For 1D flames, at normal pressure and temperature, with an increase of Karlovitz number from 0 to 0.4, the mass burning rate is first reduced and then enhanced by Soret diffusion of H2 while it is reduced by Soret diffusion of H. The influence of Soret diffusion of H2 is enhanced by pressure and reduced by temperature. On the contrary, the influence of Soret diffusion of H is reduced by pressure and enhanced by temperature. For 2D flames, at normal pressure and temperature, during the early phase of flame evolution, flames with Soret diffusion display more curved flame cells. Pressure enhances this effect, while temperature reduces it. The influence of Soret diffusion of H2 on the global consumption speed is enhanced at elevated pressure. The influence of Soret diffusion of H on the global consumption speed is enhanced at elevated temperature. The flame evolution is more affected by Soret diffusion in the early phase of propagation than in the long run due to the local enrichment of H2 caused by flame curvature effects. The present study provides new insights into the Soret diffusion effect on the characteristics of lean hydrogen/air flames at conditions that are relevant to practical applications, e.g. gas engines and turbines.

  17. Influence of Child and Adult Elevated Blood Pressure on Adult Arterial Stiffness: The Cardiovascular Risk in Young Finns Study.

    Science.gov (United States)

    Aatola, Heikki; Koivistoinen, Teemu; Tuominen, Heikki; Juonala, Markus; Lehtimäki, Terho; Viikari, Jorma S A; Raitakari, Olli T; Kähönen, Mika; Hutri-Kähönen, Nina

    2017-09-01

    Elevated blood pressure (BP) in childhood has been associated with increased adult arterial stiffness, the independent predictor of cardiovascular and all-cause mortality. The favorable BP change from childhood to adulthood and the risk of high adult arterial stiffness has not been reported. We examined the effect of child and adult BP on pulse wave velocity (PWV) assessed in adulthood among 1540 white adults followed-up for 27 years since baseline (1980, aged 6-18 years). Childhood elevated BP was defined according to the tables from the National High Blood Pressure Education Program. In adulthood, BP was classified as elevated if systolic BP ≥120 mm Hg, diastolic BP ≥80 mm Hg, or self-reported use of antihypertensive medications. PWV was measured in 2007 by whole-body impedance cardiography, and high PWV was defined as values at or above the age-, sex-, and heart rate-specific 80th percentile. Individuals with persistently elevated BP and individuals with normal child but elevated adult BP had increased risk of high adult PWV (relative risk [95% confidence interval], 3.18 [2.22-4.55] and 2.64 [1.79-3.88], respectively) in comparison with individuals with normal (both child and adult) BP. In contrast, individuals with elevated BP in childhood but not in adulthood did not have significantly increased risk of high PWV (relative risk [95% confidence interval], 1.26[0.80-1.99]). The results were consistent when different definitions for child and adult elevated BP were applied. These findings highlight the importance of BP control in the primary prevention of cardiovascular diseases. © 2017 American Heart Association, Inc.

  18. Excessive blood pressure elevation upon awakening involves an exaggerated cardiac response to slight physical activity: a possible mechanism underlying the risk of 'morning surge'.

    Science.gov (United States)

    Wakamatsu, Yoshimasa; Takeda, Yutaka; Tanaka, Satoru; Yamamoto, Koji; Yamashita, Sumiyo; Sugiura, Tomonori; Dohi, Yasuaki; Kimura, Genjiro

    2012-10-01

    An exaggerated elevation in blood pressure around waking potentially increases the risk of cardiovascular events, even in individuals with normal blood pressure at other-fold of day. The impact of such a transient blood pressure elevation is disproportionate to its short duration, and the reason has not been elucidated. We hypothesize that individuals with such a blood pressure abnormality receive a cardiovascular overload, even from slight physical activities that are frequently undertaken in daily life. A total of 16 patients with essential hypertension (52 ± 15 years) staying at hospital for lifestyle education participated in this study. Morning blood pressure elevation was assessed with 24 h ambulatory blood pressure monitoring. Cardiovascular responses to unloaded pedaling, including blood pressure changes, were assessed in a limited maximum exercise test using an electronically braked bicycle ergometer. Changes in the systolic blood pressure caused by unloaded pedaling correlated positively with the elevation in systolic blood pressure around waking (r = 0.52, P = 0.05). Moreover, waking elevation of the systolic blood pressure correlated with changes in all of the following cardiovascular variables during unloaded pedaling: heart rate (r = 0.69, P = 0.003), oxygen consumption (r = 0.73, P = 0.001), oxygen pulse (r = 0.62, P = 0.001), and rate pressure product (r = 0.64, P = 0.008), respectively. These observations indicate that individuals with prominent blood pressure elevation upon awakening also experience cardiovascular overload from slight physical activities.

  19. The effect of pressurization path on high pressure gas forming of Ti-3Al-2.5V at elevated temperature

    Directory of Open Access Journals (Sweden)

    Liu Gang

    2015-01-01

    Full Text Available High pressure gas forming is a tubular component forming technology with pressurized gas at elevated temperature, based on QPF, HMGF and Hydroforming. This process can be used to form tube blank at lower temperatures with high energy efficiency and also at higher strain rates. With Ti-3Al-2.5V Ti-alloy tube, the potential of HPGF was studied further through experiments at the elevated temperatures of 650 ∘C and 700 ∘C. In order to know the formability of the Ti-alloy tube, tensile tests were also carried out. The results show that: at the temperatures of 650 ∘C and 700 ∘C, the flow curves exhibit the power-law constitutive relation until peak stress is reached and the deformability is suitable for the HPGF process of Ti-3Al-2.5V alloy tube. The effects of pressurization path on the corner filling process and thickness profile are obvious. The high pressure inflow process can result in temperature difference between the straight wall area and corner area, which makes the thickness profile special. Besides, with the stepped pressurization path, the more constant filling rate and better thickness profile can be obtained.

  20. Genetic context determines susceptibility to intraocular pressure elevation in a mouse pigmentary glaucoma

    Directory of Open Access Journals (Sweden)

    Cosma Ioan M

    2006-07-01

    Full Text Available Abstract Background DBA/2J (D2 mice develop an age-related form of glaucoma. Their eyes progressively develop iris pigment dispersion and iris atrophy followed by increased intraocular pressure (IOP and glaucomatous optic nerve damage. Mutant alleles of the Gpnmb and Tyrp1 genes are necessary for the iris disease, but it is unknown whether alleles of other D2 gene(s are necessary for the distinct later stages of disease. We initiated a study of congenic strains to further define the genetic requirements and disease mechanisms of the D2 glaucoma. Results To further understand D2 glaucoma, we created congenic strains of mice on the C57BL/6J (B6 genetic background. B6 double-congenic mice carrying D2-derived Gpnmb and Tyrp1 mutations develop a D2-like iris disease. B6 single-congenics with only the Gpnmb and Tyrp1 mutations develop milder forms of iris disease. Genetic epistasis experiments introducing a B6 tyrosinase mutation into the congenic strains demonstrated that both the single and double-congenic iris diseases are rescued by interruption of melanin synthesis. Importantly, our experiments analyzing mice at ages up to 27 months indicate that the B6 double-congenic mice are much less prone to IOP elevation and glaucoma than are D2 mice. Conclusion As demonstrated here, the Gpnmb and Tyrp1 iris phenotypes are both individually dependent on tyrosinase function. These results support involvement of abnormal melanosomal events in the diseases caused by each gene. In the context of the inbred D2 mouse strain, the glaucoma phenotype is clearly influenced by more genes than just Gpnmb and Tyrp1. Despite the outward similarity of pigment-dispersing iris disease between D2 and the B6 double-congenic mice, the congenic mice are much less susceptible to developing high IOP and glaucoma. These new congenic strains provide a valuable new resource for further studying the genetic and mechanistic complexity of this form of glaucoma.

  1. High pressure-elevated temperature x-ray micro-computed tomography for subsurface applications.

    Science.gov (United States)

    Iglauer, Stefan; Lebedev, Maxim

    2018-06-01

    Physical, chemical and mechanical pore-scale (i.e. micrometer-scale) mechanisms in rock are of key importance in many, if not all, subsurface processes. These processes are highly relevant in various applications, e.g. hydrocarbon recovery, CO 2 geo-sequestration, geophysical exploration, water production, geothermal energy production, or the prediction of the location of valuable hydrothermal deposits. Typical examples are multi-phase flow (e.g. oil and water) displacements driven by buoyancy, viscous or capillary forces, mineral-fluid interactions (e.g. mineral dissolution and/or precipitation over geological times), geo-mechanical rock behaviour (e.g. rock compaction during diagenesis) or fines migration during water production, which can dramatically reduce reservoir permeability (and thus reservoir performance). All above examples are 3D processes, and 2D experiments (as traditionally done for micro-scale investigations) will thus only provide qualitative information; for instance the percolation threshold is much lower in 3D than in 2D. However, with the advent of x-ray micro-computed tomography (μCT) - which is now routinely used - this limitation has been overcome, and such pore-scale processes can be observed in 3D at micrometer-scale. A serious complication is, however, the fact that in the subsurface high pressures and elevated temperatures (HPET) prevail, due to the hydrostatic and geothermal gradients imposed upon it. Such HPET-reservoir conditions significantly change the above mentioned physical and chemical processes, e.g. gas density is much higher at high pressure, which strongly affects buoyancy and wettability and thus gas distributions in the subsurface; or chemical reactions are significantly accelerated at increased temperature, strongly affecting fluid-rock interactions and thus diagenesis and deposition of valuable minerals. It is thus necessary to apply HPET conditions to the aforementioned μCT experiments, to be able to mimic subsurface

  2. Intraocular pressure elevation precedes a phagocytosis decline in a model of pigmentary glaucoma [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Yalong Dang

    2018-04-01

    Full Text Available Background: Outflow regulation and phagocytosis are key functions of the trabecular meshwork (TM, but it is not clear how the two are related in secondary open angle glaucomas characterized by an increased particle load. We hypothesized that diminished TM phagocytosis is not the primary cause of early ocular hypertension and recreated pigment dispersion in a porcine ex vivo model. Methods: Sixteen porcine anterior chamber cultures received a continuous infusion of pigment granules (Pg, while 16 additional anterior chambers served as controls (C. Pressure transducers recorded the intraocular pressure (IOP. The phagocytic capacity of the trabecular meshwork was determined by fluorescent microspheres. Results: The baseline IOPs in Pg and C were similar (P=0.82. A significant IOP elevation occurred in Pg at 48, 120, and 180 hours (all P0.05. Conclusions: In this porcine model of pigmentary glaucoma, an IOP elevation occurs much earlier than when phagocytosis fails, suggesting that two separate mechanisms might be at work.

  3. A Pilot Study: Comparison of Arm Versus Ankle Noninvasive Blood Pressure Measurement at 2 Different Levels of Backrest Elevation.

    Science.gov (United States)

    Henley, Nicole; Quatrara, Beth D; Conaway, Mark

    2015-01-01

    Standard practice for obtaining noninvasive blood pressure includes arm blood pressure (BP) cuff placement at the level of the heart; however, some critical care patients cannot have BPs taken in their arm because of various conditions, and ankle BPs are frequently used as substitutes. The aim of this study was to determine if there was a significant variation between upper arm and ankle BP measurements at different backrest elevations with consideration of peripheral edema factors. After institutional review board approval was obtained, a pilot study was implemented to evaluate noninvasive BP measurements of the arm and ankle with backrest elevation at 0° and 30° in a population of medical intensive care unit patients. Participants served as their own controls and were randomly assigned to left- versus right-side BP readings. Data were also collected on presence of arm versus ankle edema. A total of 30 participants enrolled in the study and provided 120 BP measurements. Blood pressure readings were analyzed in terms of diastolic and systolic findings as well as backrest elevations and edema presence. Thirteen participants presented with either arm or ankle edema. There was a statistical difference between the systolic arm and ankle BP measurements in the 0° (P = .008) and 30° (P arm and ankle diastolic BP is greater for participants without ankle edema (P = .038, r = 0.54) than for participants with ankle edema (P = .650, r = 0.14), but it is not statistically significant (P = .47). Even though ankle BPs are often substituted for arm BPs when the arm is unable to be used, ankle BPs and arm BPs are not interchangeable. Adjustments in backrest elevation and considerations of edema do not normalize the differences. Blood pressures obtained from the ankle are significantly greater than those obtained from the arm. This information needs to be considered when arms are not available and legs are used as surrogates for the upper arm.

  4. Lifestyle Patterns Are Associated with Elevated Blood Pressure among Qatari Women of Reproductive Age: A Cross-Sectional National Study

    Directory of Open Access Journals (Sweden)

    Mohammed Al Thani

    2015-09-01

    Full Text Available Women of childbearing age are particularly vulnerable to the adverse effects of elevated blood pressure (BP, with dietary and lifestyle habits being increasingly recognized as important modifiable environmental risk factors for this condition. Using data from the National STEPwise survey conducted in Qatar in year 2012, we aimed to examine lifestyle patterns and their association with elevated BP among Qatari women of childbearing age (18–45 years. Socio-demographic, lifestyle, dietary, anthropometric and BP data were used (n = 747. Principal component factor analysis was applied to identify the patterns using the frequency of consumption of 13 foods/food groups, physical activity level, and smoking status. Multivariate logistic regression analyses were used to evaluate the association of the identified lifestyle patterns with elevated BP and to examine the socio-demographic correlates of these patterns. Three lifestyle patterns were identified: a “healthy” pattern characterized by intake of fruits, natural juices, and vegetables; a “fast food & smoking” pattern characterized by fast foods, sweetened beverages, and sweets, in addition to smoking; and a “traditional sedentary” pattern which consisted of refined grains, dairy products, and meat in addition to low physical activity. The fast food & smoking and the traditional & sedentary patterns were associated with an approximately 2-fold increase in the risk of elevated BP in the study population. The findings of this study highlight the synergistic effect that diet, smoking and physical inactivity may have on the risk of elevated BP among Qatari women.

  5. Lifestyle Patterns Are Associated with Elevated Blood Pressure among Qatari Women of Reproductive Age: A Cross-Sectional National Study.

    Science.gov (United States)

    Al Thani, Mohammed; Al Thani, Al Anoud; Al-Chetachi, Walaa; Al Malki, Badria; Khalifa, Shamseldin A H; Bakri, Ahmad Haj; Hwalla, Nahla; Nasreddine, Lara; Naja, Farah

    2015-09-09

    Women of childbearing age are particularly vulnerable to the adverse effects of elevated blood pressure (BP), with dietary and lifestyle habits being increasingly recognized as important modifiable environmental risk factors for this condition. Using data from the National STEPwise survey conducted in Qatar in year 2012, we aimed to examine lifestyle patterns and their association with elevated BP among Qatari women of childbearing age (18-45 years). Socio-demographic, lifestyle, dietary, anthropometric and BP data were used (n = 747). Principal component factor analysis was applied to identify the patterns using the frequency of consumption of 13 foods/food groups, physical activity level, and smoking status. Multivariate logistic regression analyses were used to evaluate the association of the identified lifestyle patterns with elevated BP and to examine the socio-demographic correlates of these patterns. Three lifestyle patterns were identified: a "healthy" pattern characterized by intake of fruits, natural juices, and vegetables; a "fast food & smoking" pattern characterized by fast foods, sweetened beverages, and sweets, in addition to smoking; and a "traditional sedentary" pattern which consisted of refined grains, dairy products, and meat in addition to low physical activity. The fast food & smoking and the traditional & sedentary patterns were associated with an approximately 2-fold increase in the risk of elevated BP in the study population. The findings of this study highlight the synergistic effect that diet, smoking and physical inactivity may have on the risk of elevated BP among Qatari women.

  6. An Experimental Investigation on the NO and CO Emission Characteristics of a Swirl Convergent-Divergent Nozzle at Elevated Pressure

    Directory of Open Access Journals (Sweden)

    Zhongya Xi

    2018-05-01

    Full Text Available The behavior of the pollutants NO and CO at elevated combustor pressure are of special importance due to the continuing trend toward developing engines operating at higher pressure ratios to yield higher thermal efficiency. An experiment was performed to examine the NO and CO emissions for a swirl convergent-divergent nozzle at elevated pressure. The NO and CO correlations were obtained. Meanwhile, the flame length, exhaust gas oxygen concentration, exit temperature and global flame residence time were also determined to analyze the NO and CO emission characteristics. The results showed that, with the increase in combustor pressure P, flame length decreased proportionally to P−0.49; exit O2 volume fraction increased and exit temperature was reduced. The global flame residence time decreased proportionally to P−0.43. As pressure increased, The NO and Emission Index of NO (EINO levels decreased proportionally to P−0.53 and P−0.6 respectively, which is mainly attributed to the influence of global flame residence time; the NO and EINO increased almost proportionally with the increase in global flame residence time. The EINO scaling EINO (ρue/d was proportional to Fr0.42, which indicated that compared with pure fuel, the fuel diluted with primary air can cause a decrease in the exponent of the Fr power function. At higher pressure, the CO and Emission Index of CO (EICO decreased proportionally to P−0.35 and P−0.4, respectively, due to the increased unburned methane and high pressure which accelerated chemical reaction kinetics to promote the conversion of CO to CO2.

  7. Association of elevated blood pressure with low distress and good quality of life: results from the nationwide representative German Health Interview and Examination Survey for Children and Adolescents.

    Science.gov (United States)

    Berendes, Angela; Meyer, Thomas; Hulpke-Wette, Martin; Herrmann-Lingen, Christoph

    2013-05-01

    Quality of life is often impaired in patients with known hypertension, but it is less or not at all reduced in people unaware of their elevated blood pressure. Some studies have even shown less self-rated distress in adults with elevated blood pressure. In this substudy of the nationwide German Health Interview and Examination Survey for Children and Adolescents (KIGGS), we addressed the question whether, also in adolescents, hypertensive blood pressure is linked to levels of distress and quality of life. Study participants aged 11 to 17 years (N = 7688) received standardized measurements of blood pressure, quality of life (using the Children's Quality of Life Questionnaire), and distress (Strengths and Difficulties Questionnaire). Elevated blood pressure was twice as frequent as expected, with 10.7% (n = 825) above published age-, sex- and height-adjusted 95th percentiles. Hypertensive participants were more likely to be obese and to report on adverse health behaviors, but they showed better academic success than did normotensive participants. Elevated blood pressure was significantly and positively associated with higher self- and parent-rated quality of life (for both, p ≤ .006), less hyperactivity (for both, p parent-rated emotional (p pressure to better well-being and low distress can partly be explained by the absence of confounding physical comorbidity and the unawareness of being hypertensive. It also corresponds to earlier research suggesting a bidirectional relationship with repressed emotions leading to elevated blood pressure and, furthermore, elevated blood pressure serving as a potential stress buffer.

  8. Elevated Blood Pressure and Obesity in Childhood: A Cross-Sectional Evaluation of 4,609 Schoolchildren

    Directory of Open Access Journals (Sweden)

    Caroline Filla Rosaneli

    2014-09-01

    Full Text Available Background: The incidence of obesity in children is increasing worldwide, primarily in urbanized, high-income countries, and hypertension development is a detrimental effect of this phenomenon. Objective: In this cross-sectional study, we evaluated the prevalence of excess weight and its association with high blood pressure (BP in schoolchildren. Methods: Here 4,609 male and female children, aged 6 to 11 years, from 24 public and private schools in Maringa, Brazil, were evaluated. Nutritional status was assessed by body mass index (BMI according to cutoff points adjusted for sex and age. Blood pressure (BP levels above 90th percentile for gender, age and height percentile were considered elevated. Results: The prevalence of excess weight among the schoolchildren was 24.5%; 16.9% were overweight, and 7.6% were obese. Sex and socioeconomic characteristics were not associated with elevated BP. In all age groups, systolic and diastolic BP correlated with BMI and waist and hip measurements, but not with waist-hip ratio. The prevalence of elevated BP was 11.2% in eutrophic children, 20.6% in overweight children [odds ratio (OR, 1.99; 95% confidence interval (CI, 1.61-2.45], and 39.7% in obese children (OR, 5.4; 95% CI, 4.23-6.89. Conclusion: Obese and overweight children had a higher prevalence of elevated BP than normal-weight children. Our data confirm that the growing worldwide epidemic of excess weight and elevated BP in schoolchildren may also be ongoing in Brazil.

  9. Variables predicting elevated portal pressure in alcoholic liver disease. Results of a multivariate analysis

    DEFF Research Database (Denmark)

    Krogsgaard, K; Christensen, E; Gluud, C

    1987-01-01

    In 46 alcoholic patients the association of wedged-to-free hepatic-vein pressure with other variables (clinical, histologic, hemodynamic, and liver function data) was studied by means of multiple regression analysis, taking the wedged-to-free hepatic-vein pressure as the dependent variable. Four ...

  10. Effects of elevated temperature and pore pressure on the mechanical behavior of Bullfrog tuff

    International Nuclear Information System (INIS)

    Olsson, W.A.

    1982-02-01

    Samples of the Bullfrog Member of the Crater Flat Tuff from the depth interval 758.9 to 759.2 m in hole USW-G1 on the Nevada Test Site were tested in triaxial compression. Test conditions were: (1) effective confining pressure to 20 MPa; (2) temperature of 200 0 C; (3) both dry and with pore water pressures from 3.4 to 5 MPa; and (4) a strain-rate of 10 -4 /s. The results suggest that the presence of water causes the strength to decrease. In addition, the brittle-ductile transition pressure for this rock was found to be about 15 MPa, regardless of saturation. Below this pressure deformation is characterized by unstable stress drops and the development of a single fracture, and above this pressure deformation is stable and distributed more uniformly throughout the sample

  11. Determining pH at elevated pressure and temperature using in situ ¹³C NMR.

    Science.gov (United States)

    Surface, J Andrew; Wang, Fei; Zhu, Yanzhe; Hayes, Sophia E; Giammar, Daniel E; Conradi, Mark S

    2015-02-03

    We have developed an approach for determining pH at elevated pressures and temperatures by using (13)C NMR measurements of inorganic carbon species together with a geochemical equilibrium model. The approach can determine in situ pH with precision better than 0.1 pH units at pressures, temperatures, and ionic strengths typical of geologic carbon sequestration systems. A custom-built high pressure NMR probe was used to collect (13)C NMR spectra of (13)C-labeled CO2 reactions with NaOH solutions and Mg(OH)2 suspensions at pressures up to 107 bar and temperatures of 80 °C. The quantitative nature of NMR spectroscopy allows the concentration ratio [CO2]/[HCO3(-)] to be experimentally determined. This ratio is then used with equilibrium constants calculated for the specific pressure and temperature conditions and appropriate activity coefficients for the solutes to calculate the in situ pH. The experimentally determined [CO2]/[HCO3(-)] ratios agree well with the predicted values for experiments performed with three different concentrations of NaOH and equilibration with multiple pressures of CO2. The approach was then applied to experiments with Mg(OH)2 slurries in which the change in pH could track the dissolution of CO2 into solution, rapid initial Mg(OH)2 dissolution, and onset of magnesium carbonate precipitation.

  12. 77 FR 3281 - High Pressure Steel Cylinders From China; Scheduling of the Final Phase of Countervailing Duty...

    Science.gov (United States)

    2012-01-23

    ...)] High Pressure Steel Cylinders From China; Scheduling of the Final Phase of Countervailing Duty and... retarded, by reason of subsidized and less-than-fair-value imports from China of high pressure steel... (``high pressure steel cylinders''). High pressure steel cylinders are fabricated of chrome alloy steel...

  13. Breakfast skippers display a disrupted cortisol rhythm and elevated blood pressure

    Science.gov (United States)

    Chronic stress and over-activity in the hypothalamic-pituitary-adrenal (HPA) axis may link breakfast skipping and poor cardiometabolic health. Missing the first major meal of the day in rodents prolongs elevated circulating corticosterone at a time when it’s normally decreasing. To extend these fi...

  14. Characterisation of a Planar Solid Oxide Cell Stack Operated at Elevated Pressure

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Graves, Christopher R.; Chen, Ming

    2016-01-01

    As the global and local energy production becomes more dependent on intermittent renewable sources like wind and solar, efficient and reversible conversion of electricity to storable fuels becomes increasingly important. Solid oxide cells (SOCs) are interesting in this context since they can...... be operated either as electrolysers (SOEC) to convert electricity to fuels such as hydrogen or methane, and as fuel cells (SOFC) to convert fuels to electricity. Both productivity and conversion efficiency can be improved if the SOC operation pressure can be increased from ambient pressure to 10-30 bar. Here...... and heat exchangers is analyzed and the expected impact of pressurization on the hydrogen production cost is evaluated....

  15. Home Blood Pressure Monitoring as an Alternative to Confirm Diagnoses of Hypertension in Adolescents with Elevated Office Blood Pressure from a Brazilian State Capital

    Science.gov (United States)

    Póvoa, Thaís Inacio Rolim; Jardim, Thiago Veiga; Carneiro, Carolina de Souza; Ferreira, Vanessa Roriz; Mendonça, Karla Lorena; de Morais, Polyana Resende Silva; Nascente, Flávia Miquetichuc Nogueira; de Souza, Weimar Kunz Sebba Barroso; Sousa, Ana Luiza Lima; Jardim, Paulo César Brandão Veiga

    2017-01-01

    Background Regional differences of using home blood pressure monitoring (HBPM) as an alternative to ambulatory blood pressure monitoring (ABPM) in hypertensive adolescents are unknown. Objectives Define if HBPM is an option to confirm diagnoses of hypertension in adolescents from a Brazilian capital with elevated office blood pressure (BP). Methods Adolescents (12-18years) from public and private schools with BP > 90th percentile were studied to compare and evaluate the agreement among office BP measurements, HBPM and ambulatory BP monitoring. Office BP measurements, HBPM and ABPM were performed according to guidelines recommendations. Semi-automatic devices were used for BP measurements. Values of p ABPM values (120.3 ± 12.6 mmHg x 121.5 ± 9.8 mmHg - p = 0.111 and 69.4 ± 7.7 mmHg x 70.2 ± 6.6 mmHg - p = 0.139) and lower than the office measurement values (127.3 ± 13.8 mmHg over 74.4 ± 9.5 mmHg - p ABPM. Conclusions HBPM is an option to confirm diagnoses of hypertension in adolescents from a Brazilian state capital with elevated office BP and can be used as an alternative to ABPM. PMID:28793045

  16. Elevated blood pressure in offspring of rats exposed to diverse chemicals during pregnancy

    Science.gov (United States)

    Adverse intrauterine environments are associated with increased risk of later disease, including cardiovascular disease and hypertension. As a potential bioindicator of such an adverse environment, we measured blood pressure (BP), renal nephron endowment, renal glucocorticoid rec...

  17. Study on nitrogen diluted propane-air premixed flames at elevated pressures and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Tang Chenglong; Zheng Jianjun [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Huang Zuohua, E-mail: zhhuang@mail.xjtu.edu.c [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Wang Jinhua [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2010-02-15

    Using a high pressure constant volume combustion vessel, the propagation and morphology of spark-ignited outwardly expanding nitrogen diluted propane-air flames were imaged and recorded by schlieren photography and high-speed digital camera. The unstretched laminar burning velocities and Markstein lengths were subsequently determined over wide range of initial temperatures, initial pressures and nitrogen dilution ratios. Two recently developed mechanisms were used to predict the reference laminar burning velocity. The results show that the measured unstretched laminar burning velocities agree well with those in the literature and the computationally predicted results. The flame images show that the diffusional-thermal instability is promoted as the mixture becomes richer, and the hydrodynamic instability is increased with the increase of the initial pressure and it is decreased with the increase of dilution ratio. The normalized laminar burning velocities show a linear correlation with respect to the dilution ratio, indicating that the effect of nitrogen dilution is more obvious at higher pressures.

  18. Measurement of amino acid levels in the vitreous humor of rats after chronic intraocular pressure elevation or optic nerve transection.

    Science.gov (United States)

    Levkovitch-Verbin, Hana; Martin, Keith R G; Quigley, Harry A; Baumrind, Lisa A; Pease, Mary Ellen; Valenta, Danielle

    2002-10-01

    To investigate whether the levels of free amino acids and protein in the vitreous of rat eyes are altered with chronic intraocular pressure (IOP) elevation or after optic nerve transection. The concentrations of 20 amino acids in the vitreous humor were measured by high-performance liquid chromatography in both eyes of 41 rats with unilateral IOP elevation induced by translimbal photocoagulation. Eyes were studied 1 day and 1, 2, 4, and 9 weeks after initial IOP elevation. The same amino acids were measured in 41 rats 1 day and 2, 4, and 9 weeks after unilateral transection of the orbital optic nerve. The intravitreal protein level was assayed in additional 22 rats with IOP elevation and 12 rats after nerve transection. Two masked observers evaluated the amount of optic nerve damage with a semiquantitative, light-microscopic technique. In rats with experimental glaucoma, amino acid concentrations were unchanged 1 day after treatment. At 1 week, 4 of 20 amino acids (aspartate, proline, alanine, and lysine) were higher than in control eyes ( 0.05). Vitreous protein level was significantly higher in glaucomatous eyes than their paired controls at 1 day ( 0.01).

  19. Morning pulse pressure is associated more strongly with elevated albuminuria than systolic blood pressure in patients with type 2 diabetes mellitus: post hoc analysis of a cross-sectional multicenter study.

    Science.gov (United States)

    Ushigome, Emi; Fukui, Michiaki; Hamaguchi, Masahide; Matsumoto, Shinobu; Mineoka, Yusuke; Nakanishi, Naoko; Senmaru, Takafumi; Yamazaki, Masahiro; Hasegawa, Goji; Nakamura, Naoto

    2013-09-01

    Recently, focus has been directed toward pulse pressure as a potentially independent risk factor for micro- and macrovascular disease. This study was designed to examine the relationship between pulse pressure taken at home and elevated albuminuria in patients with type 2 diabetes. This study is a post hoc analysis of a cross-sectional multicenter study. Home blood pressure measurements were performed for 14 consecutive days in 858 patients with type 2 diabetes. We investigated the relationship between systolic blood pressure or pulse pressure in the morning or in the evening and urinary albumin excretion using univariate and multivariate analyses. Furthermore, we measured area under the receiver-operating characteristic curve (AUC) to compare the ability to identify elevated albuminuria, defined as urinary albumin excretion equal to or more than 30 mg/g creatinine, of systolic blood pressure or pulse pressure. Morning systolic blood pressure (β=0.339, Ppressure (β=0.378, PAUC for elevated albuminuria in morning systolic blood pressure and morning pulse pressure were 0.668 (0.632-0.705; PAUC of morning pulse pressure was significantly greater than that of morning systolic blood pressure (P=0.040). Our findings implicate that morning pulse pressure is associated with elevated albuminuria in patients with type 2 diabetes, which suggests that lowering morning pulse pressure could prevent the development and progression of diabetic nephropathy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. The structure of MgO-SiO2 glasses at elevated pressure.

    Science.gov (United States)

    Wilding, Martin; Guthrie, Malcolm; Kohara, Shinji; Bull, Craig L; Akola, Jaakko; Tucker, Matt G

    2012-06-06

    The magnesium silicate system is an important geophysical analogue and neutron diffraction data from glasses formed in this system may also provide an initial framework for understanding the structure-dependent properties of related liquids that are important during planetary formation. Neutron diffraction data collected in situ for a single composition (38 mol% SiO(2)) magnesium silicate glass sample shows local changes in structure as pressure is increased from ambient conditions to 8.6 GPa at ambient temperature. A method for obtaining the fully corrected, total structure factor, S(Q), has been developed that allows accurate structural characterization as this weakly scattering glass sample is compressed. The measured S(Q) data indicate changes in chemical ordering with pressure and the real-space transforms show an increase in Mg-O coordination number and a distortion of the local environment around magnesium ions. We have used reverse Monte Carlo methods to compare the high pressure and ambient pressure structures and also compare the high pressure form with a more silica-poor glass (Mg(2)SiO(4)) that represents the approach to a more dense, void-free and topologically ordered structure. The Mg-O coordination number increases with pressure and we also find that the degree of continuous connectivity of Si-O bonds increases via a collapse of interstices.

  1. Systems genetics identifies a role for Cacna2d1 regulation in elevated intraocular pressure and glaucoma susceptibility.

    Science.gov (United States)

    Chintalapudi, Sumana R; Maria, Doaa; Di Wang, Xiang; Bailey, Jessica N Cooke; Hysi, Pirro G; Wiggs, Janey L; Williams, Robert W; Jablonski, Monica M

    2017-11-24

    Glaucoma is a multi-factorial blinding disease in which genetic factors play an important role. Elevated intraocular pressure is a highly heritable risk factor for primary open angle glaucoma and currently the only target for glaucoma therapy. Our study helps to better understand underlying genetic and molecular mechanisms that regulate intraocular pressure, and identifies a new candidate gene, Cacna2d1, that modulates intraocular pressure and a promising therapeutic, pregabalin, which binds to CACNA2D1 protein and lowers intraocular pressure significantly. Because our study utilizes a genetically diverse population of mice with known sequence variants, we are able to determine that the intraocular pressure-lowering effect of pregabalin is dependent on the Cacna2d1 haplotype. Using human genome-wide association study (GWAS) data, evidence for association of a CACNA2D1 single-nucleotide polymorphism and primary open angle glaucoma is found. Importantly, these results demonstrate that our systems genetics approach represents an efficient method to identify genetic variation that can guide the selection of therapeutic targets.

  2. Balancing Model Performance and Simplicity to Predict Postoperative Primary Care Blood Pressure Elevation.

    Science.gov (United States)

    Schonberger, Robert B; Dai, Feng; Brandt, Cynthia A; Burg, Matthew M

    2015-09-01

    Because of uncertainty regarding the reliability of perioperative blood pressures and traditional notions downplaying the role of anesthesiologists in longitudinal patient care, there is no consensus for anesthesiologists to recommend postoperative primary care blood pressure follow-up for patients presenting for surgery with an increased blood pressure. The decision of whom to refer should ideally be based on a predictive model that balances performance with ease-of-use. If an acceptable decision rule was developed, a new practice paradigm integrating the surgical encounter into broader public health efforts could be tested, with the goal of reducing long-term morbidity from hypertension among surgical patients. Using national data from US veterans receiving surgical care, we determined the prevalence of poorly controlled outpatient clinic blood pressures ≥140/90 mm Hg, based on the mean of up to 4 readings in the year after surgery. Four increasingly complex logistic regression models were assessed to predict this outcome. The first included the mean of 2 preoperative blood pressure readings; other models progressively added a broad array of demographic and clinical data. After internal validation, the C-statistics and the Net Reclassification Index between the simplest and most complex models were assessed. The performance characteristics of several simple blood pressure referral thresholds were then calculated. Among 215,621 patients, poorly controlled outpatient clinic blood pressure was present postoperatively in 25.7% (95% confidence interval [CI], 25.5%-25.9%) including 14.2% (95% CI, 13.9%-14.6%) of patients lacking a hypertension history. The most complex prediction model demonstrated statistically significant, but clinically marginal, improvement in discrimination over a model based on preoperative blood pressure alone (C-statistic, 0.736 [95% CI, 0.734-0.739] vs 0.721 [95% CI, 0.718-0.723]; P for difference 1 of 4 patients (95% CI, 25

  3. Does elevating image receptor increase breast receptor footprint and improve pressure balance?

    International Nuclear Information System (INIS)

    Smith, H.; Szczepura, K.; Mercer, C.; Maxwell, A.; Hogg, P.

    2015-01-01

    There is no consensus in the literature regarding the image receptor (IR) position for the cradio-caudal projection in mammography. Some literature indicates the IR should be positioned to the infra mammary fold (IMF); other literature suggests the IR be raised 2 cm relative to the IMF. Using 16 female volunteers (32 breasts) and a pressure sensitive mat we investigated breast footprint and pressure balance with IR at IMF and IR 2 cm above the IMF. Breast area on IR and paddle and interface pressure between IR/breast and paddle/breast were recorded. A uniformity index (UI) gave a measure of pressure balance between IR/breast and paddle/breast. IR breast footprint increases significantly by 13.81 cm 2 (p < 0.02) when IR is raised by 2 cm. UI reduces from 0.4 to 0.00 (p = 0.04) when positioned at IMF +2 cm demonstrating an improved pressure balance. Practitioners should consider raising the IR by 2 cm relative to the IMF in clinical practice. Further work is suggested to investigate the effects of practitioner variability and breast asymmetry. - Highlights: • Experimental study. • 16 female volunteers/32 breasts. • Compares two methods of conducting the cranio-caudal project. • Provides sufficient evidence to indicate which method is likely to be superior. • Has value to clinical mammography.

  4. Interfacial tension measurement between CO2 and brines under high temperature and elevated pressure conditions

    Science.gov (United States)

    Li, X.; Boek, E. S.; Maitland, G. C.; Trusler, J. P. M.

    2012-04-01

    We have investigated the dependence of interfacial tension of (CO2 + brine) on temperature, pressure and salinity (including both salt type and molality) over the range of conditions applicable to CO2 storage in saline aquifers. The study covered a wide range of measurements of the interfacial tensions between carbon dioxide and (NaCl + KCl)(aq), CaCl2(aq), MgCl2(aq), Na2SO4(aq), KHCO3(aq), NaHCO3(aq) and two laboratory constructed brines with molality ranging from (0.3 to 5.0) mol·kg-1. The measurements were made at temperatures between (298 and 448) K at various pressures up to 50 MPa, using the pendant drop method in a high-pressure view cell filled with water-saturated CO2. The drop to be imaged was created by injecting brine from a high-pressure syringe pump into a capillary sealed through the top of the cell. The expanded uncertainties of the experimental state variables at 95 % confidence are +0.05 K in temperature and +70 kPa in pressure. For the interfacial tension, the overall expanded relative uncertainty at 95 % confidence was +1.6%. The experimental results show that interfacial tension for all the systems increases linearly with molality, indicating that relatively few measurements and simple interpolation procedures are adequate for describing this property accurately over wide ranges of conditions.

  5. Progress in understanding the mechanical behavior of pressure-vessel materials at elevated temperatures

    International Nuclear Information System (INIS)

    Swindeman, R.W.; Brinkman, C.R.

    1981-01-01

    Progress during the 1970's on the production of high-temperature mechanical properties data for pressure vessel materials was reviewed. The direction of the research was toward satisfying new data requirements to implement advances in high-temperature inelastic design methods. To meet these needs, servo-controlled testing machines and high-resolution extensometry were developed to gain more information on the essential behavioral features of high-temperature alloys. The similarities and differences in the mechanical response of various pressure vessel materials were identified. High-temperature pressure vessel materials that have received the most attention included Type 304 stainless steel, Type 316 stainless steel, 2 1/4 Cr-1 Mo steel, alloy 800H, and Hastelloy X

  6. Characterization of a Planar Solid Oxide Cell Stack Operated at Elevated Pressure

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Graves, Christopher R.; Chen, Ming

    2016-01-01

    As global and local energy production becomes more dependent on intermittent renewable sources like wind and solar, efficient and reversible conversion of electricity to storable fuels becomes increasingly important. Solid oxide cells (SOCs) are interesting in this context since they can...... be operated either as electrolyzers (SOEC) to convert electricity to fuels such as hydrogen or methane, and as fuel cells (SOFC) to convert fuels to electricity. Both productivity and conversion efficiency can be improved if the SOC operation pressure can be increased from ambient pressure to 10–30 bar...... in this paper. Additionally, the expected impact on the hydrogen production efficiency and cost is discussed....

  7. System and process for capture of acid gasses at elevated pressure from gaseous process streams

    Science.gov (United States)

    Heldebrant, David J.; Koech, Phillip K.; Linehan, John C.; Rainbolt, James E.; Bearden, Mark D.; Zheng, Feng

    2016-09-06

    A system, method, and material that enables the pressure-activated reversible chemical capture of acid gasses such as CO.sub.2 from gas volumes such as streams, flows or any other volume. Once the acid gas is chemically captured, the resulting product typically a zwitterionic salt, can be subjected to a reduced pressure whereupon the resulting product will release the captures acid gas and the capture material will be regenerated. The invention includes this process as well as the materials and systems for carrying out and enabling this process.

  8. Non-linearity parameter of binary liquid mixtures at elevated pressures

    Indian Academy of Sciences (India)

    parameter B/A of four binary liquid mixtures using Tong and Dong equation at high pressures and .... in general as regular or ideal as no recognized association takes place between the unlike molecules. In this case ... Using the definition and.

  9. Interactions of hydrogen with graphite at low pressure and elevated temperature

    International Nuclear Information System (INIS)

    Hoinkis, E.

    1991-03-01

    The plasma facing components of the vacuum chamber for thermonuclear fusion experiments are clad with graphite. Recycling of gases affects the plasma properties, and the tritium quantity accumulated in the graphite during the operation of Tokamaks with DT must be known. An adsorption isotherm for deuterium on the nuclear grade graphitic Matrix A3-3 was measured by using a volumetric method at 1173 K at pressures c = 2.5 eV/D 2 using Fowler's equation and isotherms were calculated for this E c value. These isotherms predict saturation of the adsorption sites in graphite at T D2 > 0.1 Pa. At T > 1173 K and P D2 -2 Pa the adsorbed quantity is less than 1% of the saturation level. The release kinetics of deuterium was measured at temperatures uo to 2000 K. D 2 desorption commenced at 1170 K. The maximum of the release rate is observed at T p = 1770 K. A Lennard-Jones potential energy diagram was calculated, which suggests a C-H bond energy E b ≅ 3.4 eV/D and an activation energy of desorption E d ≅ 4 eV/D 2 . The partial pressures of hydrocarbons C n ≤3 H m in equilibrium with graphite were calculated. At total pressures -2 Pa the partial pressures of these hydrocarbons are less than 10 -7 Pa in the temperature range 600-1500 K. (orig./MM)

  10. Noise exposure in occupational setting associated with elevated blood pressure in China

    Directory of Open Access Journals (Sweden)

    Shuchang Chen

    2017-01-01

    Full Text Available Abstract Background Hypertension is the primary out-auditory adverse outcome caused due to occupational noise exposure. This study investigated the associations of noise exposure in an occupational setting with blood pressure and risk of hypertension. Methods A total of 1,390 occupational noise-exposed workers and 1399 frequency matched non-noise-exposed subjects were recruited from a cross-sectional survey of occupational noise-exposed and the general population, respectively. Blood pressure was measured using a mercury sphygmomanometer following a standard protocol. Multiple logistic regression was used to calculate the odds ratio (OR and 95% confidence interval (CI of noise exposure adjusted by potential confounders. Results Noise-exposed subjects had significantly higher levels of systolic blood pressure(SBP (125.1 ± 13.9 mm Hg and diastolic blood pressure (DBP (77.6 ± 10.7 mm Hg than control subjects (SBP: 117.2 ± 15.7 mm Hg, DBP: 70.0 ± 10.5 mm Hg (P  0.05. Conclusions Occupational noise exposure was associated with higher levels of SBP, DBP, and the risk of hypertension. These findings indicate that effective and feasible measures should be implemented to reduce the risk of hypertension caused by occupational noise exposure.

  11. Maxillary sinus floor elevation via crestal approach: the evolution of the hydraulic pressure technique.

    Science.gov (United States)

    Lopez, Michele Antonio; Andreasi Bassi, Mirko; Confalone, Luca; Carinci, Francesco

    2014-01-01

    The current study describes an innovative protocol for the surgical maxillary sinus augmentation via a crestal approach that uses hydraulic pressure to lift the Schneiderian membrane and simultaneously fill the subantral space with a biomaterial for bone regeneration (nanocrystalline hydroxyapatite in aqueous solution). The technique in question combines the advantages of large amounts of grafted biomaterial with reduced trauma, high precision, and predictability.

  12. Performance and metallography of a uranium tritide bed operated at elevated temperatures and tritium pressures

    International Nuclear Information System (INIS)

    Mote, M.W. Jr.; Mintz, J.M.

    1986-12-01

    A uranium gettering bed was cycled between room temperature/zero pressure and 600C/275 psi (D 2 ) for 210 cycles over a period of 8 months. Metallographic examination of the hardware revealed an acceptable amount of reaction between the uranium and the stainless steel container. This exposure is estimated to represent about ten years of normal use

  13. Passive control of thermoacoustic instabilities in swirl-stabilized combustion at elevated pressures

    Directory of Open Access Journals (Sweden)

    L Justin Williams

    2016-09-01

    Full Text Available In this study, a porous insert is placed at the dump plane of a swirl-stabilized lean premixed combustor to passively suppress thermoacoustic instabilities. The diffuser-shaped annular ring of porous inert material influences the turbulent flow field directly, including recirculation zones and vortical and/or shear layer structures to passively control the acoustic performance of the combustor. The porous inert material is made of silicon carbide–hafnium carbide coated, high-strength, high-temperature-resistant open-cell foam materials. In this study, the porous insert concept is investigated at above-ambient operating pressures to demonstrate its suitability for practical combustion applications. Experiments are conducted in quartz and metal combustors, without and with the porous insert while varying operating pressure, equivalence ratio, and reactant flow rate. Measurements show that the porous insert, and consequent changes in the combustor flow field, decrease the sound pressure levels at the frequency of combustion instability at all operating conditions investigated in this study. The porous insert also decreases the broadband combustion noise, i.e. the measured sound pressure levels over a wide frequency range.

  14. Models of WO x films growth during pulsed laser deposition at elevated pressures of reactive gas

    Science.gov (United States)

    Gnedovets, A. G.; Fominski, V. Y.; Nevolin, V. N.; Romanov, R. I.; Fominski, D. V.; Soloviev, A. A.

    2017-12-01

    The films of tungsten oxides were prepared by pulsed laser ablation of W target in a reactive gas atmosphere (air of laboratory humidity). Optical analysis and ion signal measurements for the laser plume allowed to recognise a threshold gas pressure that suppresses the deposition of non-scattered atomic flux from the plume. When the pressure exceeds about 40 Pa, the films grow due to the deposition of species that could be formed in collisions of W atoms with reactive molecules (e.g., O2). Kinetic Monte Carlo method was used for modelling film growth. Comparison of the model structures with the experimentally prepared films has shown that the growth mechanism of ballistic deposition at a pressure of 40 Pa could be changed on the diffusion limited aggregation at a pressure of ~100 Pa. Thus, a cauliflower structure of the film transformed to a web-like structure. For good correlation of experimental and model structures of WO x , a dimension of structural elements in the model should coincide with W-O cluster size.

  15. Predicting fluorescence quantum yield for anisole at elevated temperatures and pressures

    Science.gov (United States)

    Wang, Q.; Tran, K. H.; Morin, C.; Bonnety, J.; Legros, G.; Guibert, P.

    2017-07-01

    Aromatic molecules are promising candidates for using as a fluorescent tracer for gas-phase scalar parameter diagnostics in a drastic environment like engines. Along with anisole turning out an excellent temperature tracer by Planar Laser-Induced Fluorescence (PLIF) diagnostics in Rapid Compression Machine (RCM), its fluorescence signal evolution versus pressure and temperature variation in a high-pressure and high-temperature cell have been reported in our recent paper on Applied Phys. B by Tran et al. Parallel to this experimental study, a photophysical model to determine anisole Fluorescence Quantum Yield (FQY) is delivered in this paper. The key to development of the model is the identification of pressure, temperature, and ambient gases, where the FQY is dominated by certain processes of the model (quenching effect, vibrational relaxation, etc.). In addition to optimization of the vibrational relaxation energy cascade coefficient and the collision probability with oxygen, the non-radiative pathways are mainly discussed. The common non-radiative rate (intersystem crossing and internal conversion) is simulated in parametric form as a function of excess vibrational energy, derived from the data acquired at different pressures and temperatures from the literature. A new non-radiative rate, namely, the equivalent Intramolecular Vibrational Redistribution or Randomization (IVR) rate, is proposed to characterize anisole deactivated processes. The new model exhibits satisfactory results which are validated against experimental measurements of fluorescence signal induced at a wavelength of 266 nm in a cell with different bath gases (N2, CO2, Ar and O2), a pressure range from 0.2 to 4 MPa, and a temperature range from 473 to 873 K.

  16. Low job control is associated with higher diastolic blood pressure in men with mildly elevated blood pressure: the Rosai Karoshi study.

    Science.gov (United States)

    Hattori, Tomomi; Munakata, Masanori

    2015-01-01

    Job strain is a risk factor for hypertension, but it is not fully understood if components of job strain, or job demand or job control per se could be related to blood pressure (BP), and if so, whether the relationship differs between normotension and mildly elevated BP. We examined resting BP, and job stress components in 113 Japanese male hospital clerks (38.1 ± 4.4 yr). Subjects were classified into normotensive (NT) (<130/85 mmHg, n=83) and mildly elevated BP (ME) (≥130/85 mmHg) groups. Diastolic BP (DBP) showed a significant interaction between group and job control level (p=0.013). Subjects with low job control demonstrated higher DBP than those with high job control (89.1 ± 2.1 vs. 82.3 ± 2.3 mmHg, p=0.042) in ME group even after adjustments for covariates while DBP did not differ between low and high job control subjects in NT group. Systolic BP (SBP) did not differ between high and low job control subjects in both groups. Neither SBP nor DBP differed between high and low demand groups in either group. Among job strain components, job control may be independently related to BP in Japanese male workers with mildly elevated BP.

  17. Virgin Coconut Oil Prevents Blood Pressure Elevation and Improves Endothelial Functions in Rats Fed with Repeatedly Heated Palm Oil

    Directory of Open Access Journals (Sweden)

    Badlishah Sham Nurul-Iman

    2013-01-01

    Full Text Available This study was performed to explore the effects of virgin coconut oil (VCO in male rats that were fed with repeatedly heated palm oil on blood pressure, plasma nitric oxide level, and vascular reactivity. Thirty-two male Sprague-Dawley rats were divided into four groups: (i control (basal diet, (ii VCO (1.42 mL/kg, oral, (iii five-times-heated palm oil (15% (5HPO, and (iv five-times-heated palm oil (15% and VCO (1.42 mL/kg, oral (5HPO + VCO. Blood pressure was significantly increased in the group that was given the 5HPO diet compared to the control group. Blood pressure in the 5HPO + VCO group was significantly lower than the 5HPO group. Plasma nitric oxide (NO level in the 5HPO group was significantly lower compared to the control group, whereas in the 5HPO + VCO group, the plasma NO level was significantly higher compared to the 5HPO group. Aortic rings from the 5HPO group exhibited attenuated relaxation in response to acetylcholine and sodium nitroprusside as well as increased vasoconstriction to phenylephrine compared to the control group. Aortic rings from the 5HPO + VCO group showed only attenuated vasoconstriction to phenylephrine compared to the 5HPO group. In conclusion, VCO prevents blood pressure elevation and improves endothelial functions in rats fed with repeatedly heated palm oil.

  18. "EFFECTIVENESS OF ABDOMINAL WALL ELEVATOR IN REDUCING INTRA-ABDOMINAL PRESSURE AND CO2 VOLUME DURING LAPAROSCOPIC CHOLECYSTECTOMY"

    Directory of Open Access Journals (Sweden)

    A. Yaghoobi Notash

    2004-06-01

    Full Text Available Since CO2 pneumoperitoneum is the dominant method of laparoscopic exposure due to facility and good view, its physiologic effects are most relevant to the surgeons. CO2 pneumoperitoneum may affects hemodynamics by increased intra-abdominal pressure (IAP and the physiologic effects of absorbed CO2. The adverse effects of both mechanisms relate directly to the duration of the pneumoperitoneum and the elevation of IAP. Gasless laparoscopy involves obtaining exposure for laparoscopy by placing an internal retracting device through a small incision and lifting the anterior abdominal wall. We designed and made a mechanical wall elevator and used it in 24 patients, compared with a control group (52 cases using a conventional laparoscopic cholecystectomy. A prospective trial was undertaken in Sina Hospital, Tehran University of Medical Sciences from 1998 to 2000. The patients were assigned randomly to two groups. There was a significant decrease in IAP and CO2 consumption in the group using mechanical wall elevator as compared to conventional laparoscopic cholecystectomy, (mean IAP of 3.5 mmHg compared to 11.4 mmHg in the control group, mean CO2 volume 17 liters compared to 73 liters in the control group. We recommend this semigasless method in laparoscopy due to safety in performance and significant reduction in IAP through the surgery. This method provides a satisfactory view and easy performance without any increase in time or complications. The hospital stay and costs did not increase.

  19. [Transient elevation of intraocular pressure in primary open-angle glaucoma patients after automated visual field examination in the winter].

    Science.gov (United States)

    Nishino, Kazuaki; Yoshida, Fujiko; Nitta, Akari; Saito, Mieko; Saito, Kazuuchi

    2013-12-01

    To evaluate retrospectively seasonal fluctuations of transient intraocular pressure (IOP) elevation after automated visual field examination in patients with primary open-angle glaucoma (POAG). We reviewed 53 consecutive patients with POAG who visited Kaimeido Ophthalmic and Dental Clinic from January 2011 to March 2013, 21 men and 32 women aged 67.7 +/- 11.2 years. The patients were divided into 4 groups, spring, summer, autumn, and winter according to the month of automated visual field examination and both eyes of each patient were enrolled. IOP was measured immediately after automated visual field examination (vf IOP) and compared with the average IOP from the previous 3 months (pre IOP) and with the average IOP from the following 3 months (post IOP) in each season. IOP elevation rate was defined as (vf IOP- pre IOP)/pre IOP x 100% and calculated for each season (paired t test). Additionally, the correlation between mean deviation (MD) and IOP elevation rate was evaluated (single regression analysis). Exclusion criteria were patients who received cataract surgery during this study or had a history of any previous glaucoma surgery. The automated visual field test was performed with a Humphrey field analyzer and the Central 30-2 FASTPAC threshold program. The average vf IOP was 14.5 +/- 2.5 mmHg, higher than pre IOP 13.8 +/- 2.4 mmHg (p field examination, especially in the winter but not in the summer.

  20. Determining noncondensible gas fractions at elevated temperatures and pressures using wet and dry bulb temperature measurements

    International Nuclear Information System (INIS)

    Griffith, P.; Bowman, J.

    1987-01-01

    The work reported in this note was undertaken to provide a method of determining the noncondensible gas fractions in a steam-gas mixture such as might be found in large reactor safety experiment like LOFT. In essence, the method used involves measuring the wet and dry bulb temperatures and using an algorithm, in place of the psychometric chart, to determine the partial pressure of the noncondensible gas in the mixture. In accomplishing this, the authors did the following: (1) extended the use of wet and dry-bulb temperature readings to determine mixture composition up to a temperature of 589 K and a pressure of 4.13 x 10 6 Pa. (2) developed an algorithm to reduce the data (3) found which materials would survive those temperatures

  1. The lifetime of a long cylindrical shell under external pressure at elevated temperature

    CERN Document Server

    Bargmann, H W

    1972-01-01

    This paper is concerned with creep collapse of a long, thin walled, circular, cylindrical shell subjected to external pressure. The problem has been studied by Hoff et al. (1959), where elasticity has been neglected in the material equations. In the present paper it is pointed out that elasticity must not be neglected in stability problems as it may reduce the lifetime considerably. The improved equation for the lifetime of the shell is presented. Moreover, a procedure is indicated to derive the necessary creep parameters easily from usually available creep data. Numerical values of the lifetime of thin-walled, circular, cylindrical shells under external atmospheric pressure are presented for a wide range of shells of different geometrical characteristics for a number of high-temperature alloys and the temperature range up to 1000 degrees C. Experimental results are reported which are in good agreement with the theoretical prediction. (11 refs).

  2. Vapor-liquid Phase Equilibria for CO2+Tertpentanol Binary System at Elevated Pressures

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; LUO Jian-cheng; YANG Hao; CHEN Kai-xun

    2011-01-01

    Vapor-liquid phase equilibrium data of tertpentanol in carbon dioxide were measured at temperatures of 313.4,323.4,333.5 and 343.5 K and in the pressure range of 4.56-11.44 MPa.The phase equilibium apparatus used in the work was a variable-volume high-pressure cell.The experimental data were reasonably correlated with Peng-Robinson equation of state(PR-EOS) together with van der Waals-2 two-parameter mixing rules.Henry's Law constants and partial molar volumes of CO2 at infinite dilution were estimated with Krichevsky-Kasarnovsky equation,and Henry's Law constants increase with increasing temperature,however,partial molar volumes of CO2 at infinite dilution are negative whose magnitudes decrease with temperature.Partial molar volumes of CO2 and tertpentanol in liquid phase at equilibrium were calculated.

  3. A Poroelasticity Theory Approach to Study the Mechanisms Leading to Elevated Interstitial Fluid Pressure in Solid Tumours.

    Science.gov (United States)

    Burazin, Andrijana; Drapaca, Corina S; Tenti, Giuseppe; Sivaloganathan, Siv

    2018-05-01

    Although the mechanisms responsible for elevated interstitial fluid pressure (IFP) in tumours remain obscure, it seems clear that high IFP represents a barrier to drug delivery (since the resulting adverse pressure gradient implies a reduction in the driving force for transvascular exchange of both fluid and macromolecules). R. Jain and co-workers studied this problem, and although the conclusions drawn from their idealized mathematical models offered useful insights into the causes of elevated IFP, they by no means gave a definitive explanation for this phenomenon. In this paper, we use poroelasticity theory to also develop a macroscopic mathematical model to describe the time evolution of a solid tumour, but focus our attention on the mechanisms responsible for the rise of the IFP, from that for a healthy interstitium to that measured in malignant tumours. In particular, we discuss a number of possible time scales suggested by our mathematical model and propose a tumour-dependent time scale that leads to results in agreement with experimental observations. We apply our mathematical model to simulate the effect of "vascular normalization" (as proposed by Jain in Nat Med 7:987-989, 2001) on the IFP profile and discuss and contrast our conclusions with those of previous work in the literature.

  4. An Ignition Torch Based on Photoignition of Carbon Nanotubes at Elevated Pressure (Briefing Charts)

    Science.gov (United States)

    2016-01-04

    Applications The schematic image of high pressure ignition torch with a remotely operated Xe-flash lamp PITCH provides certain advantages over...combustible fuel mixture • The low voltage (< 350 v) discharge in PITCH produces no electromagnetic interference and its operation is not affected by...EMI or electrostatic discharge • Use of multiple PITCH igniters greatly enhanced the chance of ignition of turbines • The connecting tube delivers

  5. Silicon Monoxide at 1 atm and Elevated Pressures: Crystalline or Amorphous?

    KAUST Repository

    AlKaabi, Khalid

    2014-03-05

    The absence of a crystalline SiO phase under ordinary conditions is an anomaly in the sequence of group 14 monoxides. We explore theoretically ordered ground-state and amorphous structures for SiO at P = 1 atm, and crystalline phases also at pressures up to 200 GPa. Several competitive ground-state P = 1 atm structures are found, perforce with Si-Si bonds, and possessing Si-O-Si bridges similar to those in silica (SiO2) polymorphs. The most stable of these static structures is enthalpically just a little more stable than a calculated random bond model of amorphous SiO. In that model we find no segregation into regions of amorphous Si and amorphous SiO2. The P = 1 atm structures are all semiconducting. As the pressure is increased, intriguing new crystalline structures evolve, incorporating Si triangular nets or strips and stishovite-like regions. A heat of formation of crystalline SiO is computed; it is found to be the most negative of all the group 14 monoxides. Yet, given the stability of SiO2, the disproportionation 2SiO (s) → Si(s)+SiO2(s) is exothermic, falling right into the series of group 14 monoxides, and ranging from a highly negative ΔH of disproportionation for CO to highly positive for PbO. There is no major change in the heat of disproportionation with pressure, i.e., no range of stability of SiO with respect to SiO2. The high-pressure SiO phases are metallic. © 2014 American Chemical Society.

  6. Right ventricular pressure elevated in one-kidney, one clip Goldblatt hypertensive rats.

    Science.gov (United States)

    Ketabchi, Farzaneh; Bajoovand, Shirin; Adlband, Mojtaba; Naseh, Maryam; Nekooeian, Ali A; Mashghoolozekr, Elaheh

    2017-01-01

    Both renal and respiratory diseases are common with high mortality rate around the world. This study was the first to compare effects of two kidneys, one clip (2K1C) and one-kidney, one clip (1K1C) Goldblatt hypertension on right ventricular pressure during normal condition and mechanical ventilation with hypoxia gas. Male Sprague-Dawley rats were subjected to control, 2K1C, or 1K1C groups. Twenty-eight days after the first surgery, animals were anesthetized, and femoral artery and vein, and right ventricle cannulated. Systemic arterial pressure and right ventricular systolic pressures (RVSP) were recorded during ventilation the animals with normoxic or hypoxic gas. RVSP in the 1K1C group was significantly more than the control and 2K1C groups during baseline conditions and ventilation the animals with hypoxic gas. Administration of antioxidant Trolox increased RVSP in the 1K1C and control groups compared with their baselines. Furthermore, there was no alteration in RVSP during hypoxia in the presence of Trolox. This study indicated that RVSP only increased after 28 days induction of 1K1C but not 2K1C model. In addition, it seems that the response to hypoxic gas and antioxidants in 1K1C is more than 2K1C. These data also suggest that effects of 1K1C may partially be related to reactive oxygen species (ROS) pathways.

  7. Fluid and rock interactions in silicate and aluminosilicate systems at elevated pressure and temperature

    Science.gov (United States)

    Davis, Mary Kathleen

    Understanding fluid chemistry in the subduction zone environment is key to unraveling the details of element transport from the slab to the surface. Solubilities of cations, such as silicon, in water strongly affect both the physical and chemical properties of supercritical metamorphic fluids. Modeling the thermodynamics of fluid-rock interactions requires therefore a profound understanding of cation dissolution and aqueous speciation. In situ Raman experiments of the silica-water, alumina-water, and alumina water systems were performed in an externally heated Bassett-type diamond-anvil cell at the Department of Geological Sciences, University of Michigan. Natural quartz samples and synthetic ruby samples were used in the experiments. Samples were loaded in the sample chamber with a water pressure medium. All experiments used rhenium gaskets of uniform thickness with a 500 mum drill hole for the sample chamber. Temperature was measured using K-type thermocouples encompassing both the upper and lower diamond anvils. Pressures are obtained on the basis of the Raman shift of the 464 cm-1 quartz mode where possible or the Raman shift of the tips of the diamond anvils according to a method developed in this work. This work characterizes the state of stress in the diamond anvil cell, which is used as the basis for the pressure calibration using only the diamond anvils. Raman measurements of silicate fluid confirm the presence of H4 SiO4 and H6Si2O7 in solution and expand the pressure range for in-situ structural observations in the silica-water system. Additionally, we identify the presence of another silica species present at mantle conditions, which occurs at long time scales in the diamond cell. This study provides the first in situ data in the alumina-water and alumina-silica-water systems at pressures and temperatures relevant to the slab environment. Al(OH) 3 appears to be the dominant form of alumina present under these conditions and in the alumina

  8. Structural evolution of a uranyl peroxide nano-cage fullerene: U60, at elevated pressures

    Science.gov (United States)

    Turner, K. M.; Lin, Y.; Zhang, F.; McGrail, B.; Burns, P. C.; Mao, W. L.; Ewing, R. C.

    2015-12-01

    U60 is a uranyl peroxide nano-cage that adopts a highly symmetric fullerene topology; it is topologically identical to C60. Several studies on the aqueous-phase of U60 clusters, [UO2(O2)(OH)]6060-, have shown its persistence in complex solutions and over lengthy time scales. Peroxide enhances corrosion of nuclear fuel in a reactor accident-uranyl peroxides often form near contaminated sites. U60 (Fm-3) crystallizes with approximate formula: Li68K12(OH)20[UO2(O2)(OH)]60(H2O)310. Here, we have used the diamond anvil cell (DAC) to examine U60 to understand the stability of this cluster at high pressures. We used a symmetric DAC with 300 μm culet diamonds and two different pressure-transmitting media: a mixture of methanol+ethanol and silicone oil. Using a combination of in situ Raman spectroscopy and synchrotron XRD, and electrospray ionization mass spectroscopy (ESI-MS) ex situ, we have determined the pressure-induced evolution of U60. Crystalline U60 undergoes an irreversible phase transition to a tetragonal structure at 4.1 GPa, and irreversibly amorphizes at 13 GPa. The amorphous phase likely consists of clusters of U60. Above 15 GPa, the U60 cluster is irreversibly destroyed. ESI-MS shows that this phase consists of species that likely have between 10-20 uranium atoms. Raman spectroscopy complements the diffraction measurements. U60 shows two dominant vibrational modes: a symmetric stretch of the uranyl U-O triple bond (810 cm-1), and a symmetric stretch of the U-O2-U peroxide bond (820 cm-1). As pressure is increased, these modes shift to higher wavenumbers, and overlap at 4 GPa. At 15 GPa, their intensity decreases below detection. These experiments reveal several novel behaviors including a new phase of U60. Notably, the amorphization of U60 occurs before the collapse of its cluster topology. This is different from the behavior of solvated C60 at high pressure, which maintains a hcp structure up to 30 GPa, while the clusters disorder. These results suggest

  9. 77 FR 26739 - High Pressure Steel Cylinders From the People's Republic of China: Final Determination of Sales...

    Science.gov (United States)

    2012-05-07

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-977] High Pressure Steel... LTFV are shown in the ``Final Determination Margins'' section of this notice. \\1\\ See High Pressure... affiliated producers, Langfang Tianhai High Pressure Contain Co., Ltd. (``Langfang Tianhai''), which produced...

  10. Spectral domain optical coherence tomography cross-sectional image of optic nerve head during intraocular pressure elevation

    Directory of Open Access Journals (Sweden)

    Ji Young Lee

    2014-12-01

    Full Text Available AIM: To analyze changes of the optic nerve head (ONH and peripapillary region during intraocular pressure (IOP elevation in patients using spectral domain optical coherence tomography (SD-OCT.METHODS: Both an optic disc 200×200 cube scan and a high-definition 5-line raster scan were obtained from open angle glaucoma patients presented with monocular elevation of IOP (≥30 mm Hg using SD-OCT. Additional baseline characteristics included age, gender, diagnosis, best-corrected visual acuity, refractive error, findings of slit lamp biomicroscopy, findings of dilated stereoscopic examination of the ONH and fundus, IOP, pachymetry findings, and the results of visual field.RESULTS: The 24 patients were selected and divided into two groups:group 1 patients had no history of IOP elevation or glaucoma (n=14, and group 2 patients did have history of IOP elevation or glaucoma (n=10. In each patient, the study eye with elevated IOP was classified into group H (high, and the fellow eye was classified into group L (low. The mean deviation (MD differed significantly between groups H and L when all eyes were considered (P=0.047 and in group 2 (P=0.042, not in group 1 (P=0.893. Retinal nerve fiber layer (RNFL average thickness (P=0.050, rim area (P=0.015, vertical cup/disc ratio (P=0.011, cup volume (P=0.028, inferior quadrant RNFL thickness (P=0.017, and clock-hour (1, 5, and 6 RNFL thicknesses (P=0.050, 0.012, and 0.018, respectively, cup depth (P=0.008, central prelaminar layer thickness (P=0.023, mid-inferior prelaminar layer thickness (P=0.023, and nasal retinal slope (P=0.034 were significantly different between the eyes with groups H and L.CONCLUSION:RNFL average thickness, rim area, vertical cup/disc ratio, cup volume, inferior quadrant RNFL thickness, and clock-hour (1, 5, and 6 RNFL thicknesses significantly changed during acute IOP elevation.

  11. Measurements and correlations of turbulent burning velocities over wide ranges of fuels and elevated pressures

    KAUST Repository

    Bradley, Derek; Lawes, Malcolm; Liu, Kexin; Mansour, Morkous S.

    2013-01-01

    The implosion technique has been used to extend measurements of turbulent burning velocities over greater ranges of fuels and pressures. Measurements have been made up to 3.5 MPa and at strain rate Markstein numbers as low as 23. The implosion technique, with spark ignition at two opposite wall positions within a fan-stirred spherical bomb is capable of measuring turbulent burning velocities, at higher pressures than is possible with central ignition. Pressure records and schlieren high speed photography define the rate of burning and the smoothed area of the flame front. The first aim of the study was to extend the previous measurements with ethanol and propane-air, with further measurements over wider ranges of fuels and equivalence ratios with mixtures of hydrogen, methane, 10% hydrogen-90% methane, toluene, and i-octane, with air. The second aim was to study further the low turbulence regime in which turbulent burning co-exists with laminar flame instabilities. Correlations are presented of turbulent burning velocity normalised by the effective rms turbulent velocity acting on the flame front, ut=u0k , with the Karlovitz stretch factor, K, for different strain rate Markstein numbers, a decrease in which increases ut=u0k . Experimental correlations are presented for the present measurements, combined with previous ones. Different burning regimes are also identified, extending from that of mixed turbulence/laminar instability at low values of K to that at high values of K, in which ut=u0k is gradually reduced due to increasing localised flame extinctions. © 2012 The Combustion Institute.

  12. Permeability of shale at elevated temperature and pressure: Test methodology and preliminary results

    International Nuclear Information System (INIS)

    Myer, L.R.; Christian, T.L.

    1987-05-01

    A method of measuring the hydraulic conductivity of low permeability shale as a function of pressure and temperature has been developed and successfully demonstrated. Measurements have been performed on samples of Green River Formation up to a temperature of 140 0 C. For flow parallel to bedding hydraulic conductivities increased nonlinearly from 1.75 x 10 -16 m/s (1.6 x 10 -23 m 2 ) at 25 0 C, to 5.6 x 10 -15 m/s (1.4 x 10 -22 m 2 ) at 140 0 C. This increase in permeability with temperature may reflect an increase in microcrack porosity resulting from the heating

  13. Short-Term Changes in Weather and Space Weather Conditions and Emergency Ambulance Calls for Elevated Arterial Blood Pressure

    Directory of Open Access Journals (Sweden)

    Jone Vencloviene

    2018-03-01

    Full Text Available Circadian rhythm influences the physiology of the cardiovascular system, inducing diurnal variation of blood pressure. We investigated the association between daily emergency ambulance calls (EACs for elevated arterial blood pressure during the time intervals of 8:00–13:59, 14:00–21:59, and 22:00–7:59 and weekly fluctuations of air temperature (T, barometric pressure, relative humidity, wind speed, geomagnetic activity (GMA, and high-speed solar wind (HSSW. We used the Poisson regression to explore the association between the risk of EACs and weather variables, adjusting for seasonality and exposure to CO, PM10, and ozone. An increase of 10 °C when T > 1 °C on the day of the call was associated with a decrease in the risk of EACs during the time periods of 14:00–21:59 (RR (rate ratio = 0.78; p < 0.001 and 22:00–7:59 (RR = 0.88; p = 0.35. During the time period of 8:00–13:59, the risk of EACs was positively associated with T above 1 °C with a lag of 5–7 days (RR = 1.18; p = 0.03. An elevated risk was associated during 8:00–13:59 with active-stormy GMA (RR = 1.22; p = 0.003; during 14:00–21:59 with very low GMA (RR = 1.07; p = 0.008 and HSSW (RR = 1.17; p = 0.014; and during 22:00–7:59 with HSSW occurring after active-stormy days (RR = 1.32; p = 0.019. The associations of environmental variables with the exacerbation of essential hypertension may be analyzed depending on the time of the event.

  14. Thermal conductivity and diffusivity of Permian Basin bedded salt at elevated pressure and temperature

    International Nuclear Information System (INIS)

    Durham, W.B.; Boro, C.O.; Beiriger, J.M.; Montan, D.N.

    1983-10-01

    Measurements of thermal conductivity and diffusivity were made on five core samples of bedded rock salt from the Permian Basin in Texas to determine its suitability as an underground nuclear waste repository. The sample size was 100 mm in diameter by 250 mm in length. Measurements were conducted under confining pressures ranging from 3.8 to 31.0 MPa and temperatures from room temperature to 473 K. Conductivity showed no dependence on confining pressure but evidenced a monotonic, negative temperature dependence. Four of the five samples showed conductivities clustered in a range of 5.6 +- 0.5 W/m.K at room temperature, falling to 3.6 +- 0.3 W/m.K at 473 K. These values are approximately 20% below those for pure halite, reflecting perhaps the 5 to 20%-nonhalite component of the samples. Diffusivity also showed a monotonic, negative temperature dependence, with four of the five samples clustered in a range of 2.7 +- 0.4 x 10 -6 m 2 /s at room temperature, and 1.5 +- 0.3 x 10 -6 m 2 /s at 473 K, all roughly 33% below the values for pure halite. One sample showed an unusually high conductivity (it also had the highest diffusivity), about 20% higher than the others; and one sample showed an unusually low diffusivity (it also had the lowest conductivity), roughly a factor of 2 lower than the others. 27 references, 8 figures, 4 tables

  15. Tafluprost once daily for treatment of elevated intraocular pressure in patients with open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    Liu Y

    2012-12-01

    Full Text Available Yang Liu, Weiming MaoDepartment of Cell Biology and Anatomy, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TXAbstract: Glaucoma is a leading cause of visual loss worldwide. Current antiglaucoma therapy focuses on lowering intraocular pressure to a safe level. In recent years, prostaglandin analogs have become the first-line agents for treating open angle glaucoma. Tafluprost, which was first reported in 2003, is a novel prostaglandin analog, and has been shown to be a potent ocular hypotensive agent in a number of preclinical and clinical studies. Also, its unique preservative-free formulation helps to decrease preservative-associated ocular disorders and improve patient compliance. In this review, studies from 2003 to 2012 focusing on the structure, metabolism, efficacy, and safety of tafluprost are summarized. These studies suggested that application of tafluprost once daily is a safe and effective treatment for patients with open angle glaucoma.Keywords: tafluprost, prostaglandin analog, glaucoma, intraocular pressure, preservative-free formulation

  16. Creep strength of hastelloy X TIG-welded cylinder under internal pressure at elevated temperature

    International Nuclear Information System (INIS)

    Udoguchi, Teruyoshi; Indo, Hirosato; Isomura, Kazuyuki; Kobatake, Kiyokazu; Nakanishi, Tsuneo.

    1981-01-01

    Creep tests on circumferentially TIG-welded Hastelloy x cylinders were carried out under internal pressure for the investigation of structural behavior of welded components in high temperature environment. The creep rupture strength of TIG-welded cylinders was much lower than that of non-welded cylinders, while such reduction was not found in uniaxial creep tests on TIG-welded bars. It was deduced that the reduction was due to the low ductility (ranging from 1 to 5%) of the weld metal to which enhanced creep was induced by the adjacent base metal whose creep strain rate was much higher than that of the weld metal. Therefore, uniaxial creep tests on bar specimens is not sufficient for proper assessment of the creep rupture strength of welded components. Both creep strain rate and creep ductility should be concerned for the assessment. Creep tests by using components such as cylinder under internal pressure are recommendable for the confirmation of creep strength of welded structures and components. (author)

  17. 164Ile allele in the beta2-Adrenergic receptor gene is associated with risk of elevated blood pressure in women. The Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Sethi, AA; Tybjærg-Hansen, A; Jensen, Gorm Boje

    2005-01-01

    Since beta2-adrenergic receptors are important regulators of blood pressure, genetic variation in this receptor could explain risk of elevated blood pressure in selected individuals. We tested the hypothesis that Gly16Arg, Gln27Glu, and Thr164Ile in the beta2-adrenergic receptor gene associated w...

  18. Interfacial area transport in two-phase flows in a scaled 8X8 rod bundle geometry at elevated pressures

    International Nuclear Information System (INIS)

    Yang, X; Schlegel, J.P.; Paranjape, S.; Liu, Y.; Chen, S.W.; Hibiki, T.; Ishii, M.

    2011-01-01

    To improve the prediction accuracy and robustness of the next-generation thermal-hydraulics system analysis code, analytical and experimental research has been undertaken to develop the Interfacial Area Transport Equation (IATE) in a scaled 8x8 rod bundle geometry at elevated pressure conditions. The experiments performed include local measurements of void fraction, interfacial area concentration, and gas velocity at several axial locations using the innovative four-sensor conductivity probe. The test conditions cover a wide range of flow regimes from bubbly, cap-bubbly, cap-turbulent to churn-turbulent at 100 kPa and 300 kPa pressure conditions and the obtained data indicates some spacer effects on the flow parameters. The bubble groups are classified into two groups (Group-1: spherical and distorted bubbles, Group-2: cap and churn turbulent bubbles) based on the bubble transport characteristics. The area-averaged interfacial area transport data have been compared to the prediction by the one-dimensional two-group IATE with mechanistically modeled IAC source and sink terms. The one-group IATE is able to predict the bubbly-flow interfacial area within ±15% error under two pressure conditions. The two-group IATE performance is also very promising in the cap-bubbly flow and churn-turbulent flow regimes, with average error of about ±20%. (author)

  19. Pigment dispersion and chronic intraocular pressure elevation after sulcus placement of 3-piece acrylic intraocular lens.

    Science.gov (United States)

    Almond, M Camille; Wu, Michael C; Chen, Philip P

    2009-12-01

    A 55-year-old man had phacoemulsification and implantation of a 3-piece acrylic intraocular lens (IOL) (AcrySof MA60AC) in the right eye. One month postoperatively, the intraocular pressure (IOP) was 48 mm Hg and peripheral transillumination defects were noted in the iris circumferentially, with the IOL optic edge visible as a silhouette. Gonioscopy showed dense pigmentation of the trabecular meshwork in the right eye, but in the left eye, only mild trabecular meshwork pigment was seen, along with a concave peripheral iris insertion. At 21 months, the right eye required 3 medications for IOP control. While pigment dispersion has been widely reported after placement of 1-piece acrylic IOLs in the ciliary sulcus, we conclude that in susceptible individuals with a concave peripheral iris insertion, pigment dispersion can occur with sulcus placement of a 3-piece acrylic model despite its thinner optic and angulated haptics.

  20. Investigation of LPP combustors under elevated pressure conditions; Untersuchungen zu LPP-Flugtriebwerksbrennkammern unter erhoehtem Druck

    Energy Technology Data Exchange (ETDEWEB)

    Fink, R.

    2001-05-01

    The development of new combustor concepts for aero engines to meet future emissions regulations in based on a detailed knowledge of the combustion process and the velocity field. In the presented thesis, non intrusive measurements were performed in a model combustion chamber under almost realistic pressure and temperature conditions. The species OH, NO, unburned hydrocarbons and fuel droplets were detected in 2 dimensions with the Laser Induced Fluorescence (LIF). The velocity field was measured with the Particle Image Velocimetry technique (PIV). [German] Die Weiterentwicklung neuer Brennkammerkonzepte zur Erfuellung zukuenftiger Schadstoffemissionsrichtlinien erfordert genaue Kenntnisse der ablaufenden Verbrennungs- und Stroemungsvorgaenge in der Brennkammer. Bei den in der Arbeit vorgestellten Untersuchungen wurden in einer LPP-Modellbrennkammer unter annaehernd realistischen Eintrittsbedingungen die Spezies OH, NO, unverbrannte Kohlenwasserstoffe sowie noch fluessiger Brennstoff zweidimensional anhand der Laserinduzierten Fluoreszenz (LIF) nachgewiesen. Das Stroemungsfeld wurde mit Hilfe der Particle Image Velocimetry (PIV) gemessen.

  1. Laminar burning velocities at elevated pressures for gasoline and gasoline surrogates associated with RON

    KAUST Repository

    Mannaa, Ossama

    2015-06-01

    The development and validation of a new gasoline surrogate using laminar flame speed as a target parameter is presented. Laminar burning velocities were measured using a constant-volume spherical vessel with ignition at the center of the vessel. Tested fuels included iso-octane, n-heptane, toluene, various mixtures of primary reference fuels (PRFs) and toluene reference fuels (TRFs) and three gasoline fuels of 70, 85 and 95 RON (FACE J, C and F) at the initial temperature of 358K and pressures up to 0.6MPa in the equivalence ratio ranging from 0.8 to 1.6. Normalized laminar burning velocity data were mapped into a tri-component mixture space at different experimental conditions to allocate different gasoline surrogates for different gasoline fuels, having RON of 70, 85 and 95. The surrogates of TRF-70-4 (17.94% iso-C8H18 +42.06% n-C7H16 +40% C7H8), TRF-85-1 (77.4% iso-C8H18 +17.6% n-C7H16 +5% C7H8), and TRF-95-1 (88.47% iso-C8H18 +6.53% n-C7H16 +5% C7H8) of RON 70, 85 and 95, respectively, are shown to successfully emulate the burning rate characteristics of the gasoline fuels associated with these RONs under the various experimental conditions investigated. An empirical correlation was derived to obtain laminar burning velocities at pressures that are experimentally unattainable as high as 3.0MPa. Laminar burning velocities were comparable to the simulated values for lean and stoichiometric flames but they were relatively higher than the simulated values for rich flames. A flame instability assessment was conducted by determining Markstein length, critical Pecklet number, and critical Karlovitz number at the onset of flame instability.

  2. Measurement procedure for the determination of thermal exchange coefficient for subsea pipelines at elevated pressure levels

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Luis Fernando A.; Farias, Paula S.C.; Martins, Fabio J.W.A.; Rabello, Pedro C.; Barros Junior, Julio M. [Pontificia Universidade Catolica (PUC-Rio), RJ (Brazil). Dept. de Engenharia Mecanica; Lopes Junior, Fernando M.; Silva Junior, Jose Fernando; Castro, Adriana M.; Santos, Augusto A.; Pessanha, Maikon C.R. [Technip, Rio de Janeiro, RJ (Brazil)

    2009-12-19

    The present paper describes a methodology successfully employed to determine the Thermal Exchange Coefficient - TEC - for insulated sub sea flexible lines up to a pressure level of 200 bar. In this methodology, controlled internal electrical heating was employed, together with temperature sensors installed at the inner and outer surfaces of the line. The instrumented line sample was placed in a hyperbaric chamber filled with water. Two methods were employed in parallel to determine the line TEC value. In the first method, the TEC value was determined by direct measurement of the radial heat flux by the use of heat flux sensors. The readings of these sensors, together with the inner-to-outer surface temperature difference and geometric parameters, yielded the desired TEC value. In the second method, the radial heat flux was obtained as the difference between the total energy generated by the electrical heater installed in the interior of the sample and the heat losses through the end connectors, evaluated by the readings of temperature sensors installed in covers that surrounded the end connectors. The knowledge of the cover geometry, thermal properties and the temperature readings allowed for an accurate estimate of the heat lost through the covers. Both measuring methods were backed by a detailed uncertainty analysis. A calibration procedure of the second method was performed from zero to 100 bar, the pressure range where the calibration of the heat flux sensor is valid. Beyond 100 bar and up to 200 bar, the TEC values were obtained by the second method, corrected by the calibration procedure extrapolated from the 0-100 bar range. The TEC values obtained were valid under an uncertainty level of {+-} 5%. (author)

  3. How clarinettists articulate: The effect of blowing pressure and tonguing on initial and final transients.

    Science.gov (United States)

    Li, Weicong; Almeida, André; Smith, John; Wolfe, Joe

    2016-02-01

    Articulation, including initial and final note transients, is important to tasteful music performance. Clarinettists' tongue-reed contact, the time variation of the blowing pressure P¯mouth, the mouthpiece pressure, the pressure in the instrument bore, and the radiated sound were measured for normal articulation, accents, sforzando, staccato, and for minimal attack, i.e., notes started very softly. All attacks include a phase when the amplitude of the fundamental increases exponentially, with rates r ∼1000 dB s(-1) controlled by varying both the rate of increase in P¯mouth and the timing of tongue release during this increase. Accented and sforzando notes have shorter attacks (r∼1300 dB s(-1)) than normal notes. P¯mouth reaches a higher peak value for accented and sforzando notes, followed by a steady decrease for accented notes or a rapid fall to a lower, nearly steady value for sforzando notes. Staccato notes are usually terminated by tongue contact, producing an exponential decrease in sound pressure with rates similar to those calculated from the bandwidths of the bore resonances: ∼400 dB s(-1). In all other cases, notes are stopped by decreasing P¯mouth. Notes played with different dynamics are qualitatively similar, but louder notes have larger P¯mouth and larger r.

  4. Impaired Muscle Oxygenation and Elevated Exercise Blood Pressure in Hypertensive Patients: Links With Vascular Stiffness.

    Science.gov (United States)

    Dipla, Konstantina; Triantafyllou, Areti; Koletsos, Nikolaos; Papadopoulos, Stavros; Sachpekidis, Vasileios; Vrabas, Ioannis S; Gkaliagkousi, Eugenia; Zafeiridis, Andreas; Douma, Stella

    2017-08-01

    This study examined in vivo (1) skeletal muscle oxygenation and microvascular function, at rest and during handgrip exercise, and (2) their association with macrovascular function and exercise blood pressure (BP), in newly diagnosed, never-treated patients with hypertension and normotensive individuals. Ninety-one individuals (51 hypertensives and 40 normotensives) underwent office and 24-hour ambulatory BP, arterial stiffness, and central aortic BP assessment, followed by a 5-minute arterial occlusion and a 3-minute submaximal handgrip exercise. Changes in muscle oxygenated and deoxygenated hemoglobin and tissue oxygen saturation were continuously monitored by near-infrared spectroscopy and beat-by-beat BP by Finapres. Hypertensives had higher ( P age and body mass index (BMI) adjusted). When exercising at the same submaximal intensity, hypertensives required a significantly greater ( P hypertension exhibit prominent reductions in in vivo indices of skeletal muscle oxidative capacity, suggestive of mitochondrial dysfunction, and blunted muscle microvascular reactivity. These dysfunctions were associated with higher aortic systolic BP and arterial stiffness. Dysregulations in muscle oxygen delivery/utilization and microvascular stiffness, in hypertensive patients, partially contribute to their exaggerated BP during exercise. © 2017 American Heart Association, Inc.

  5. Evidence for negative effects of elevated intra-abdominal pressure on pulmonary mechanics and oxidative stress.

    Science.gov (United States)

    Davarcı, I; Karcıoğlu, M; Tuzcu, K; İnanoğlu, K; Yetim, T D; Motor, S; Ulutaş, K T; Yüksel, R

    2015-01-01

    To compare the effects of pneumoperitoneum on lung mechanics, end-tidal CO2 (ETCO2), arterial blood gases (ABG), and oxidative stress markers in blood and bronchoalveolar lavage fluid (BALF) during laparoscopic cholecystectomy (LC) by using lung-protective ventilation strategy. Forty-six patients undergoing LC and abdominal wall hernia (AWH) surgery were assigned into 2 groups. Measurements and blood samples were obtained before, during pneumoperitoneum, and at the end of surgery. BALF samples were obtained after anesthesia induction and at the end of surgery. Peak inspiratory pressure, ETCO2, and pCO2 values at the 30th minute were significantly increased, while there was a significant decrease in dynamic lung compliance, pH, and pO2 values in LC group. In BALF samples, total oxidant status (TOS), arylesterase, paraoxonase, and malondialdehyde levels were significantly increased; the glutathione peroxidase levels were significantly decreased in LC group. The serum levels of TOS and paraoxonase were significantly higher at the end of surgery in LC group. In addition, arylesterase level in the 30th minute was increased compared to baseline. Serum paraoxonase level at the end of surgery was significantly increased when compared to AWH group. Our study showed negative effects of pneumoperitoneum in both lung and systemic levels despite lung-protective ventilation strategy.

  6. Evidence for Negative Effects of Elevated Intra-Abdominal Pressure on Pulmonary Mechanics and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    I. Davarcı

    2015-01-01

    Full Text Available Objective. To compare the effects of pneumoperitoneum on lung mechanics, end-tidal CO2 (ETCO2, arterial blood gases (ABG, and oxidative stress markers in blood and bronchoalveolar lavage fluid (BALF during laparoscopic cholecystectomy (LC by using lung-protective ventilation strategy. Materials and Methods. Forty-six patients undergoing LC and abdominal wall hernia (AWH surgery were assigned into 2 groups. Measurements and blood samples were obtained before, during pneumoperitoneum, and at the end of surgery. BALF samples were obtained after anesthesia induction and at the end of surgery. Results. Peak inspiratory pressure, ETCO2, and pCO2 values at the 30th minute were significantly increased, while there was a significant decrease in dynamic lung compliance, pH, and pO2 values in LC group. In BALF samples, total oxidant status (TOS, arylesterase, paraoxonase, and malondialdehyde levels were significantly increased; the glutathione peroxidase levels were significantly decreased in LC group. The serum levels of TOS and paraoxonase were significantly higher at the end of surgery in LC group. In addition, arylesterase level in the 30th minute was increased compared to baseline. Serum paraoxonase level at the end of surgery was significantly increased when compared to AWH group. Conclusions. Our study showed negative effects of pneumoperitoneum in both lung and systemic levels despite lung-protective ventilation strategy.

  7. Heterogeneously catalyzed deuterium separation processes: Hydrogen-water exchange studies at elevated temperatures and pressures

    International Nuclear Information System (INIS)

    Halliday, J.D.; Rolston, J.H.; Au, J.C.; Den Hartog, J.; Tremblay, R.R.

    1985-01-01

    New processes for the separation of hydrogen isotopes are required to produce heavy water for CANDU nuclear reactors and to extract tritium formed in the moderator during reactor operation. Wetproofed platinum catalysts capable of promoting rapid exchange of isotopes between countercurrent flows of hydrogen and liquid water in packed columns have been developed at CRNL over the past 15 years. These catalysts provide a catalystic surface for the gas phase exchange reaction H/sub 2/O/sub (v)/ + HD/sub (g)/ ↔ HDO/sub (v)/ + H/sub 2(g)/ as well as a large liquid surface for the liquid phase isotope transfer reaction HDO/sub (v)/ + H/sub 2/O/sub (iota)/↔HDO/sub (iota)/+H/sub 2/O/sub (v)/. Any economic stand-alone heavy water separation process, based on bithermal hydrogen-water exchange over wetproofed platinum catalysts, requires rapid overall exchange of isotopes between two phases at two temperatures. Catalysts developed for cold tower operation at 25-60 0 C are now being tested in a laboratory scale stainless steel trickle bed reactor for performance and stability at simulated hot tower conditions, 150 0 C and 2.0 MPa pressure. Catalytically active layers containing platinum supported on carbon or crystalline silica and wetproofed with Teflon have been prepared on ceramic spheres and stainless steel screening and tested in both random and ordered bed columns

  8. Formation and destruction of nitrogen oxides at elevated pressures with mixed fuels; Typenoksidimuodostus ja tuhoaminen paineistetuissa olosuhteissa ja ongelmapolttoaineilla

    Energy Technology Data Exchange (ETDEWEB)

    Aho, M.; Haemaelaeinen, J.; Paakkinen, K.; Rantanen, J. [VTT Energy, Jyvaeskylae (Finland)

    1997-10-01

    Destruction of NO with NH{sub 3} (Thermal DeNO{sub x}) and formation of nitrogen oxides (especially NO{sub 2}) from fuel nitrogen were studied at elevated pressure (up to 15 bar) with a pressurized entrained flow reactor (PEFR) at conditions simulating freeboard area of pressurized fluidized bed boiler. Effect of HCl on the oxidation of CO was studied at atmospheric pressure. These results give information about emission formation during combustion of chlorine-containing wastes. N{sub x}O{sub y} formation from fuel mixtures will be studied with a new fluidized bed reactor (FBR) in 1997. Thermal DeNox-experiments were performed at p= 2-15 bar, T= 700-950 deg C. Concentrations of NO, N{sub 2}O, NO{sub 2} and NH{sub 3} were measured at different residence times (0.2-2s). After the experiments with the bare NH{sub 3}/NO mixture, the effects of two additional gases (N{sub 2}O and CO) were measured. A new reaction tube made of quartz was employed to prevent catalytic destruction of NH{sub 3}. Formation of NO{sub 2} was studied with eleven solid fuels. The first experiments were carried out at 12 bar, O{sub 2}=20-19 %, PO{sub 2}=2.4 bar and the additional ones at p=8 bar, O{sub 2}=4-5 % => PO{sub 2}=0.4 bar at 800- 900 deg C. PCA analysis was used for finding dependency between fuel properties and the convention of fuel-N to NO{sub 2}

  9. Effect of acute intraocular pressure elevation on the minimum rim width in normal, ocular hypertensive and glaucoma eyes.

    Science.gov (United States)

    Sharma, Sourabh; Tun, Tin A; Baskaran, Mani; Atalay, Eray; Thakku, Sri Gowtham; Liang, Zhang; Milea, Dan; Strouthidis, Nicholas G; Aung, Tin; Girard, Michael Ja

    2018-01-01

    To estimate and compare changes in the Bruch's membrane opening-minimum rim width (BMO-MRW) and area in normal, ocular hypertensive and glaucoma eyes following acute elevations in intraocular pressure (IOP). The optic nerve heads (ONHs) of 104 subjects (31 normals, 20 ocular hypertension (OHT) and 53 with primary glaucoma) were imaged using Spectral-domain optical coherence tomography (OCT; Spectralis, Heidelberg Engineering, Germany). IOP was raised twice by applying a force (0.64 n then 0.9 n) to the anterior sclera using an ophthalmo-dynamometer. After each IOP increment, IOP was held constant, measured with a Tonopen (AVIA applanation tonometer, Reichert, Depew, New York, USA), and ONH was rescanned with OCT. In each OCT volume, BMO-MRW and area were calculated and at each IOP increment. The baseline MRW was significantly smaller in glaucoma subjects (174.3±54.3 µm) compared with normal (287.4±42.2 µm, pglaucoma subjects was significantly thinner at the first and second IOP elevations than that at baseline (both p0.05). Acute IOP elevation leads to compression of the nerve fibre layers of neuroretinal rim in glaucoma subjects only without changing ONH size. This suggests that the neural and connective tissues at ONH level in glaucoma subjects are more susceptible to acute IOP episodes than OHT or normal controls. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. Specific Features of Structural-Phase State and Properties of Reactor Pressure Vessel Steel at Elevated Irradiation Temperature

    Directory of Open Access Journals (Sweden)

    E. A. Kuleshova

    2017-01-01

    Full Text Available This paper considers influence of elevated irradiation temperature on structure and properties of 15Kh2NMFAA reactor pressure vessel (RPV steel. The steel is investigated after accelerated irradiation at 300°C (operating temperature of VVER-1000-type RPV and 400°C supposed to be the operating temperature of advanced RPVs. Irradiation at 300°C leads to formation of radiation-induced precipitates and radiation defects-dislocation loops, while no carbide phase transformation is observed. Irradiation at a higher temperature (400°C neither causes formation of radiation-induced precipitates nor provides formation of dislocation loops, but it does increase the number density of the main initial hardening phase—of the carbonitrides. Increase of phosphorus concentration in grain boundaries is more pronounced for irradiation at 400°C as compared to irradiation at 300°C due to influence of thermally enhanced diffusion at a higher temperature. The structural-phase changes determine the changes of mechanical properties: at both irradiation temperatures irradiation embrittlement is mainly due to the hardening mechanism with some contribution of the nonhardening one for irradiation at 400°C. Lack of formation of radiation-induced precipitates at T = 400°C provides a small ΔTK shift (17°C. The obtained results demonstrate that the investigated 15Kh2NMFAA steel may be a promising material for advanced reactors with an elevated operating temperature.

  11. Numerical Modelling of Soot Formation in Laminar Axisymmetric Ethylene-Air Coflow Flames at Atmospheric and Elevated Pressures

    KAUST Repository

    Abdelgadir, Ahmed

    2015-03-30

    A set of coflow diffusion flames are simulated to study the formation, growth, and oxidation of soot in flames of diluted hydrocarbon fuels, with focus on the effects of pressure. Firstly, we assess the ability of a high performance CFD solver, coupled with detailed transport and kinetic models, to reproduce experimental measurements of a series of ethylene-air coflow flames. Detailed finite rate chemistry describing the formation of Polycyclic Aromatic Hydro-carbons is used. Soot is modeled with a moment method and the resulting moment transport equations are solved with a Lagrangian numerical scheme. Numerical and experimental results are compared for various pressures. Finally, a sensitivity study is performed assessing the effect of the boundary conditions and kinetic mechanisms on the flame structure and stabilization properties.

  12. Separating the roles of nitrogen and oxygen in high pressure-induced blood-borne microparticle elevations, neutrophil activation, and vascular injury in mice.

    Science.gov (United States)

    Yang, Ming; Bhopale, Veena M; Thom, Stephen R

    2015-08-01

    An elevation in levels of circulating microparticles (MPs) due to high air pressure exposure and the associated inflammatory changes and vascular injury that occur with it may be due to oxidative stress. We hypothesized that these responses arise due to elevated partial pressures of N2 and not because of high-pressure O2. A comparison was made among high-pressure air, normoxic high-pressure N2, and high-pressure O2 in causing an elevation in circulating annexin V-positive MPs, neutrophil activation, and vascular injury by assessing the leakage of high-molecular-weight dextran in a murine model. After mice were exposed for 2 h to 790 kPa air, there were over 3-fold elevations in total circulating MPs as well as subgroups bearing Ly6G, CD41, Ter119, CD31, and CD142 surface proteins-evidence of neutrophil activation; platelet-neutrophil interaction; and vascular injury to brain, omentum, psoas, and skeletal muscles. Similar changes were found in mice exposed to high-pressure N2 using a gas mixture so that O2 partial pressure was the same as that of ambient air, whereas none of these changes occurred after exposures to 166 kPa O2, the same partial pressure that occurs during high-pressure air exposures. We conclude that N2 plays a central role in intra- and perivascular changes associated with exposure to high air pressure and that these responses appear to be a novel form of oxidative stress. Copyright © 2015 the American Physiological Society.

  13. Final infarct size measured by cardiovascular magnetic resonance in patients with ST elevation myocardial infarction predicts long-term clinical outcome

    DEFF Research Database (Denmark)

    Lønborg, Jacob Thomsen; Vejlstrup, Niels Grove; Kelbæk, Henning Skov

    2013-01-01

    AIMS: Tailored heart failure treatment and risk assessment in patients following ST-segment elevation myocardial infarction (STEMI) is mainly based on the assessment of the left ventricular (LV) ejection fraction (EF). Assessment of the final infarct size in addition to the LVEF may improve...

  14. Turbulent burning characteristics of FACE-C gasoline and TPRF blend associated with the same RON at elevated pressures

    KAUST Repository

    Mannaa, Ossama

    2018-04-06

    Fuels for Advanced Combustion Engine (FACE)-C gasoline/air and toluene primary reference fuel (TPRF) (51.6 vol% iso-octane, 21.5 vol% n-heptane and 26.9 vol% toluene)/air mixtures corresponding to the same Research Octane numbers (RON) of 85 were characterized in terms of determining their burning rates in a fan stirred turbulent vessel and filmed using a high-speed dual Schlieren imaging technique. Also, a Mie scattering planar laser tomography was employed to characterize the variations of flame morphology induced by the simultaneous existences of different turbulent length scales and the susceptibility to develop cellular structures at elevated pressures (through the Darrieus-Landau instability). Measurements were performed in a well-controlled environment of initial pressures 0.1, 0.5 and 1.0 MPa at a fixed initial temperature of 358 K at a range of measured turbulence intensities from 0.5 to 2.0 m/s. The enhancement of turbulent burning velocity ST as a function of turbulence intensity was evaluated. The absence of bending regime was accounted for based on the size of the vessel and limited range of turbulent intensities investigated in the present work. All the present data were empirically correlated by power-law correlation derived for a different flame-type configuration to test its sensitivity to the geometry and type of the burner investigated.

  15. Elevated blood pressure and its associated risk factors among adolescents of a North Indian City - A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Senthamizh Prasad

    2017-01-01

    Full Text Available Context: Amidst the uncertainty in childhood blood pressure (BP thresholds, besides the ambiguity in levels and duration of BP elevation causing organ damage, hypertension is present in substantial number of asymptomatic children and adolescents with only a few studies disclosing the setup. With projection of deaths due to noncommunicable diseases in 2030 rising to 52 million, it is necessary to know about the knowledge of present adolescents about BP and its modifiable risk factors. Aims: (1 To assess the prevalence of elevated BP among adolescents and to ascertain the associated risk factors. (2 To assess adolescent's knowledge about BP and its modifiable factors. Settings and Design: A community-based cross-sectional study was conducted on school going adolescents of Lucknow, from September 2014 to August 2015. Subjects and Methods: BP, height, and weight were measured following standard protocols, Centers for Disease Control and Prevention charts for finding respective cut-off values and oral questionnaire for assessing lifestyle risk factors were used. Statistical Analysis: Chi-square, unpaired t-test, and logistic regression were used. Results: Of the 1041 participants, elevated BP (BP percentile ≥90 was prevalent in 24.2%. On regression, factors such as obesity (adjusted odds ratio [aOR] = 5.8, 95% confidence interval [CI] = 3.6–9.4, low fruit diet (aOR = 3.3, 95% CI = 2.1–5.4, and frequent junk food consumption (aOR = 1.9, 95% CI = 1.3–2.8 raised the odds of elevated BP while it was lowered by being physically active (aOR = 0.67, 95% CI = 0.46–0.97. Of 86.3% of children (n = 898 who were fathomed of BP, only less than third (33% and 21.9% acquainted of BP raising and lowering practices, respectively. Conclusions: Prevalence of high BP is colossal with only a few children knowing its amendable nature. Strenuous efforts targeting detrimental behaviors and imparting the sense of healthy lifestyle enhancing practices are vital to

  16. Low vapour pressure deficit reduces the beneficial effect of elevated CO{sub 2} on growth of N{sub 2}-fixing alfalfa plants

    Energy Technology Data Exchange (ETDEWEB)

    Luis, I. De; Irigoyen, J.J.; Sanchez-Diaz, M. [Univ. de Navarra, Dept. de Fisioligia Vegetal, Pamplona (Spain)

    2002-11-01

    Plant responses to elevated CO{sub 2} can be modified by many environmental factors, but very little attention has been paid to the interaction between CO{sub 2} and changes in vapour pressure deficit (VPD). Thirty-day-old alfalfa plants (Medicago sativa L. cv. Aragon), which were inoculated with Sinorhizobium meliloti 102F78 strain, were grown for 1 month in controlled environment chambers at 25/15 deg C, 14 h photoperiod, and 600 mol m{sup -2} s{sup -1} photosynthetic photon flux (PPF), using a factorial combination of CO{sub 2} concentration (400 mol mol{sup -1} or 700 mol mol{sup -1}) and vapour pressure deficit (0.48 kPa or 1.74 kPa, which corresponded to relative humidities of 85% and 45% at 25 deg C, respectively). Elevated CO{sub 2} strongly stimulated plant growth under high VPD conditions, but this beneficial effect was not observed under low VPD. Under low VPD, elevated CO{sub 2} also did not enhance plant photosynthesis, and plant water stress was greatest for plants grown at elevated CO{sub 2} and low VPD. Moreover, plants grown under elevated CO{sub 2} and low VPD had a lower leaf soluble protein and photosynthetic activity (photosynthetic rate and carboxylation efficiency) than plants grown under elevated CO{sub 2} and high VPD. Elevated CO{sub 2} significantly increased leaf adaxial and abaxial temperatures. Because the effects of elevated CO{sub 2} were dependent on vapour pressure deficit, VPD needs to be controlled in experiments studying the effect of elevated CO{sub 2} as well as considered in the extrapolations of results to a warmer, high-CO{sub 2} world. (au)

  17. Dietary sodium restriction reverses vascular endothelial dysfunction in middle-aged/older adults with moderately elevated systolic blood pressure

    Science.gov (United States)

    Jablonski, Kristen L.; Racine, Matthew L.; Geolfos, Candace J.; Gates, Phillip E.; Chonchol, Michel; McQueen, Matthew B.; Seals, Douglas R.

    2013-01-01

    Objectives We determined the efficacy of dietary sodium restriction (DSR) for improving vascular endothelial dysfunction in middle-aged/older adults with moderately elevated systolic blood pressure (SBP; 130–159 mmHg) and the associated physiological mechanisms. Background Vascular endothelial dysfunction develops with advancing age and elevated SBP, contributing to increased cardiovascular risk. DSR lowers BP, but its effect on vascular endothelial function and mechanisms involved are unknown. Methods Seventeen subjects (11M/6F; 62±7 yrs, mean±S.D.) completed a randomized, crossover study of 4 weeks of both low and normal sodium intake. Vascular endothelial function (endothelium-dependent dilation; EDD), nitric oxide (NO)/tetrahydrobiopterin (BH4) bioavailability and oxidative stress-associated mechanisms were assessed following each condition. Results Urinary sodium excretion was reduced by ~50% (to 70±30 mmol/day), and conduit (brachial artery flow-mediated dilation [FMDBA]) and resistance (forearm blood flow responses to acetylcholine [FBFACh]) artery EDD were 68% and 42% (peak FBFACh) higher following the low sodium diet (psodium markedly enhanced NO- mediated EDD (greater ΔFBFACh with endothelial NO synthase [eNOS] inhibition) without changing eNOS expression/activation (Ser1177 phosphorylation), restored BH4 bioactivity (less ΔFMDBA with acute BH4), abolished tonic superoxide suppression of EDD (less ΔFMDBA and ΔFBFACh with ascorbic acid infusion), and increased circulating superoxide dismutase activity (p<0.05). These effects were independent of ΔSBP. Other subject characteristics/dietary factors and endothelium-independent dilation were unchanged. Conclusions DSR largely reverses both macro- and microvascular endothelial dysfunction by enhancing NO and BH4 bioavailability and reducing oxidative stress. Our findings support the emerging concept that DSR induces “vascular protection” beyond that attributable to its BP-lowering effects. PMID

  18. Fundamentals of ionic conductivity relaxation gained from study of procaine hydrochloride and procainamide hydrochloride at ambient and elevated pressure.

    Science.gov (United States)

    Wojnarowska, Z; Swiety-Pospiech, A; Grzybowska, K; Hawelek, L; Paluch, M; Ngai, K L

    2012-04-28

    The pharmaceuticals, procaine hydrochloride and procainamide hydrochloride, are glass-forming as well as ionically conducting materials. We have made dielectric measurements at ambient and elevated pressures to characterize the dynamics of the ion conductivity relaxation in these pharmaceuticals, and calorimetric measurements for the structural relaxation. Perhaps due to their special chemical and physical structures, novel features are found in the ionic conductivity relaxation of these pharmaceuticals. Data of conductivity relaxation in most ionic conductors when represented by the electric loss modulus usually show a single resolved peak in the electric modulus loss M(")(f) spectra. However, in procaine hydrochloride and procainamide hydrochloride we find in addition another resolved loss peak at higher frequencies over a temperature range spanning across T(g). The situation is analogous to many non-ionic glass-formers showing the presence of the structural α-relaxation together with the Johari-Goldstein (JG) β-relaxation. Naturally the analogy leads us to name the slower and faster processes resolved in procaine hydrochloride and procainamide hydrochloride as the primary α-conductivity relaxation and the secondary β-conductivity relaxation, respectively. The analogy of the β-conductivity relaxation in procaine HCl and procainamide HCl with JG β-relaxation in non-ionic glass-formers goes further by the finding that the β-conductivity is strongly related to the α-conductivity relaxation at temperatures above and below T(g). At elevated pressure but compensated by raising temperature to maintain α-conductivity relaxation time constant, the data show invariance of the ratio between the β- and the α-conductivity relaxation times to changes of thermodynamic condition. This property indicates that the β-conductivity relaxation has fundamental importance and is indispensable as the precursor of the α-conductivity relaxation, analogous to the relation found

  19. Influence of bushenhuoxue on primary visual cortex' BDNF damage in rat model of chronic elevated intraocular pressure

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2013-04-01

    Full Text Available AIM: To observe the effect of traditional Chinese medicine(TCMof bushenhuoxue on primary visual cortex(PVCbrain-derived neurotrophic factor(BDNFin rat model of chronic elevated intraocular pressure(EIOP, and explore the mechanism of it initially. METHODS: The rat model of chronic EIOP was established by unilaterally cauterizing 3 episcleral veins, then 30 rats were divided into 3 groups randomly: control group, model group, and treatment group. After given drugs or normal saline for 8 weeks, the rats were put to death. The effect of intraocular pressure(IOP, expression of BDNF and ultrastructure of neuron cell in the PVC was observed. RESULTS: Unilaterally cauterizing episcleral veins increased IOP of the rat model obviously, there was significant difference compared with pre-operation(P<0.01. Semi-quantitative pathological analysis on PVC showed that BDNF of total area in the model group was(82438±2597.39S/μm2,mean optical density was(1155.9±123.14, integrated optical density was(12915±673.28, compared with the control group {total area was(132370±7588.47S/μm2, mean optical density was(5365±379.65, integrated optical density was(35102±2648.5}, there were statistical differences(all P<0.05,there was statistical difference in BDNF of total area between model group and treatment group{(108980±9126.77S/μm2, P<0.05}, significant difference in mean optical density between the model group and treatment group(3220.4±413.67, P<0.05, statistical difference in integrated optical density between the model group and treatment group(23821±3431.68, P<0.05. CONCLUSION: TCM of bushenhuoxue can repair the PVC damage in the rat model of chronic EIOP by enhancing expression of BDNF, improving ultrastructure of neuron cell.

  20. Vagal Blocking Improves Glycemic Control and Elevated Blood Pressure in Obese Subjects with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    S. Shikora

    2013-01-01

    Full Text Available Background. An active device that downregulates abdominal vagal signalling has resulted in significant weight loss in feasibility studies. Objective. To prospectively evaluate the effect of intermittent vagal blocking (VBLOC on weight loss, glycemic control, and blood pressure (BP in obese subjects with DM2. Methods. Twenty-eight subjects were implanted with a VBLOC device (Maestro Rechargeable System at 5 centers in an open-label study. Effects on weight loss, HbA1c, fasting blood glucose, and BP were evaluated at 1 week to 12 months. Results. 26 subjects (17 females/9 males, 51±2 years, BMI 37±1 kg/m2, mean ± SEM completed 12 months followup. One serious adverse event (pain at implant site was easily resolved. At 1 week and 12 months, mean excess weight loss percentages (% EWL were 9±1% and 25±4% (P<0.0001, and HbA1c declined by 0.3±0.1% and 1.0±0.2% (P=0.02, baseline 7.8±0.2%. In DM2 subjects with elevated BP (n=15, mean arterial pressure reduced by 7±3 mmHg and 8±3 mmHg (P=0.04, baseline 100 ± 2 mmHg at 1 week and 12 months. All subjects MAP decreased by 3 ± 2 mmHg (baseline 95 ± 2 mmHg at 12 months. Conclusions. VBLOC was safe in obese DM2 subjects and associated with meaningful weight loss, early and sustained improvements in HbA1c, and reductions in BP in hypertensive DM2 subjects. This trial is registered with ClinicalTrials.gov NCT00555958.

  1. Dynamic modeling of uteroplacental blood flow in IUGR indicates vortices and elevated pressure in the intervillous space - a pilot study

    Science.gov (United States)

    Roth, Christian J.; Haeussner, Eva; Ruebelmann, Tanja; Koch, Franz V.; Schmitz, Christoph; Frank, Hans-Georg; Wall, Wolfgang A.

    2017-01-01

    Ischemic placental disease is a concept that links intrauterine growth retardation (IUGR) and preeclampsia (PE) back to insufficient remodeling of uterine spiral arteries. The rheological consequences of insufficient remodeling of uterine spiral arteries were hypothesized to mediate the considerably later manifestation of obstetric disease. However, the micro-rheology in the intervillous space (IVS) cannot be examined clinically and rheological animal models of the human IVS do not exist. Thus, an in silico approach was implemented to provide in vivo inaccessible data. The morphology of a spiral artery and the inflow region of the IVS were three-dimensionally reconstructed to provide a morphological stage for the simulations. Advanced high-end supercomputing resources were used to provide blood flow simulations at high spatial resolution. Our simulations revealed turbulent blood flow (high-velocity jets and vortices) combined with elevated blood pressure in the IVS and increased wall shear stress at the villous surface in conjunction with insufficient spiral artery remodeling only. Post-hoc histological analysis of uterine veins showed evidence of increased trophoblast shedding in an IUGR placenta. Our data support that rheological alteration in the IVS is a relevant mechanism linking ischemic placental disease to altered structural integrity and function of the placenta.

  2. Variations in dark respiration and mitochondrial numbers within needles of Pinus radiata grown in ambient or elevated CO2 partial pressure

    International Nuclear Information System (INIS)

    Griffin, K. L.; Anderson, O. R.; Tissue, D. T.; Turnbull, M. H.; Whitehead, D.

    2004-01-01

    An experiment involving comparison of within-leaf variations in cell size, mitochondrial numbers and dark respiration in the most recently expanded tip, the mid-section and the base of needles of Pinus radiata grown for four years at ambient and elevated carbon dioxide partial pressure, is described. Results showed variation in mitochondrial numbers and respiration along the length of the needle, with the highest number of mitochondria per unit cytoplasm and the highest rate of respiration per unit leaf area at the base of the needle. Elevated carbon dioxide pressure caused the number of mitochondria per unit cytoplasm to double regardless of location (tip, basal or mid sections). Under these conditions, greatest mitochondrial density was observed at the tip. The mean size of mitochondria was not affected by either growth at elevated carbon dioxide pressure or by position on the needle. Respiration per unit leaf area at elevated carbon dioxide pressure was highest at the tip of needles, decreasing towards the middle and basal sections. The observed data supports the hypothesis that the highest number of mitochondria per unit area of cytoplasm occurs at the base of the needle, but does not support the hypothesis that the lowest rate of respiration also occurs at the base. It is suggested that the relationship that determines the association between structure and function in these needles is more complex than previously thought. 33 refs., 4 tabs., 1 fig

  3. Does an elevated CO2 concentration decrease dark respiration in trees? Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Long, Stephen [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2003-12-31

    Averaged across many previous investigations, doubling the CO2 concentration ([CO2]) has frequently been reported to cause an instantaneous reduction of leaf dark respiration measured as CO2 efflux. No known mechanism accounts for this effect. While four recent studies have shown that the measurement of respiratory CO2 efflux is prone to experimental artifacts that could account for the reported response, papers published since the start of the current research continue to report an instantaneous depression of respiratory CO2 efflux by elevation of [CO2]. Here, these artifacts are avoided by use of a high-resolution dual channel oxygen analyzer within an open gas exchange system to measure respiratory 02 uptake in normal air. Leaf 02 uptake was determined in response to instantaneous elevation of [CO2] in nine contrasting species and to long-term elevation in seven species from four of the DOE-sponsored long-term elevated [CO2] field experiments. Over one thousand separate measurements of respiration failed to reveal any decrease in respiratory 02 uptake with an instantaneous increase in [CO2]. Respiration was found insensitive not only to doubling [CO2], but also to a five-fold increase and to decrease to zero.

  4. Data Elevator

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-29

    Data Elevator: Efficient Asynchronous Data Movement in Hierarchical Storage Systems Multi-layer storage subsystems, including SSD-based burst buffers and disk-based parallel file systems (PFS), are becoming part of HPC systems. However, software for this storage hierarchy is still in its infancy. Applications may have to explicitly move data among the storage layers. We propose Data Elevator for transparently and efficiently moving data between a burst buffer and a PFS. Users specify the final destination for their data, typically on PFS, Data Elevator intercepts the I/O calls, stages data on burst buffer, and then asynchronously transfers the data to their final destination in the background. This system allows extensive optimizations, such as overlapping read and write operations, choosing I/O modes, and aligning buffer boundaries. In tests with large-scale scientific applications, Data Elevator is as much as 4.2X faster than Cray DataWarp, the start-of-art software for burst buffer, and 4X faster than directly writing to PFS. The Data Elevator library uses HDF5's Virtual Object Layer (VOL) for intercepting parallel I/O calls that write data to PFS. The intercepted calls are redirected to the Data Elevator, which provides a handle to write the file in a faster and intermediate burst buffer system. Once the application finishes writing the data to the burst buffer, the Data Elevator job uses HDF5 to move the data to final destination in an asynchronous manner. Hence, using the Data Elevator library is currently useful for applications that call HDF5 for writing data files. Also, the Data Elevator depends on the HDF5 VOL functionality.

  5. Low physical activity is a determinant for elevated blood pressure in high cardiovascular risk obstructive sleep apnea.

    Science.gov (United States)

    Mendelson, Monique; Tamisier, Renaud; Laplaud, David; Dias-Domingos, Sonia; Baguet, Jean-Philippe; Moreau, Laurent; Koltes, Christian; Chavez, Léonidas; de Lamberterie, Gilles; Herengt, Frédéric; Levy, Patrick; Flore, Patrice; Pépin, Jean-Louis

    2014-08-01

    Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity, including hypertension. Beyond the severity of nocturnal hypoxia, other factors such as metabolic abnormalities but also sedentary behaviors and insufficient physical activity may contribute to elevated blood pressure (BP). To clarify the respective role of these factors as determinants of BP in OSA patients, we examined the relationship between BP and anthropometrics, severity of sleep apnea, and objectively measured physical activity and sedentary behaviors. Ninety-five adults presenting with OSA (apnea-hypopnea index > 10 events/h) and high cardiovascular risk (63.3 ± 8.8 y; body mass index: 29.9 ± 4.9 kg/m(2); apnea-hypopnea index: 41.3 ± 17.5/h; cardiovascular risk score: 13.5 ± 3.7%) were included. Physical activity and sedentary behaviors were objectively assessed by actigraphy, and self-measured home BP monitoring was measured. Logistic regression models adjusted for sex, age, and body mass index were built to identify the predictors of self-measured morning and evening BP. Physical activity was significantly related to obesity but not to the severity of sleep apnea or sleepiness. Sedentary behaviors were associated with self-measured morning and evening systolic BP (r = 0.32, P = .002; r = 0.29, P = .004). Steps per day were inversely associated with evening BP (r = -0.27, P = .01). Univariate analysis identified steps/d and time spent in vigorous physical activity as determinants for evening self-measured BP. In multivariate analysis, only steps/d were identified as a significant determinant of evening BP. Physical activity is the major determinant for evening BP in adults with OSA presenting high cardiovascular risk. Our results emphasize the need for lifestyle counseling programs in combination with CPAP to encourage regular physical activity in OSA subjects to obtain better BP control. (ClinicalTrials.gov registration NCT01226641.)

  6. Ahmed Versus Baerveldt Glaucoma Drainage Implantation in Patients With Markedly Elevated Intraocular Pressure (≥30 mm Hg).

    Science.gov (United States)

    Resende, Arthur F; Moster, Marlene R; Patel, Neal S; Lee, Daniel; Dhami, Hermandeep; Pro, Michael J; Waisbourd, Michael

    2016-09-01

    Glaucoma patients with markedly elevated intraocular pressure (IOP) are at risk for developing severe hypotony-related complications. The goal of this study was to compare the surgical outcomes of the Ahmed Glaucoma Valve (AGV) and the Baerveldt Glaucoma Implant (BGI) in this patient population. Patients with preoperative IOP≥30 mm Hg were included. Outcome measures were: (1) surgical failure (IOP>21 mm Hg or glaucoma surgery, or loss of light perception) and (2) surgical complications. A total of 75 patients were included: 37 in the AGV group and 38 in the BGI group. The mean±SD follow-up was 2.3±1.6 years for the AGV group and 2.4±1.7 years for the BGI group (P=0.643). Mean preoperative IOP was 38.7±6.5 mm Hg for the AGV group and 40.8±7.6 mm Hg for the BGI group. At the last follow-up, 10 (27.0%) patients failed in the AGV group compared with 6 (15.8%) patients in the BGI group (P=0.379). The BGI group had higher rate of flat or shallow anterior chamber (n=4, 10%) compared with the AGV group (n=0, 0%) (P=0.043). Failure rates of AGV and BGI in patients with IOP≥30 mm Hg were comparable. There were more early hypotony-related complications in the BGI group; however, none were vision threatening. Both glaucoma drainage implants were effective in treating patients with uncontrolled glaucoma in an emergency setting.

  7. Comparison of obesity, overweight and elevated blood pressure in children attending public and private primary schools in Benin City, Nigeria.

    Science.gov (United States)

    Sadoh, W E; Israel-Aina, Y T; Sadoh, A E; Uduebor, J E; Shaibu, M; Ogonor, E; Enugwuna, F C

    2017-07-01

    Overweight and obesity in children, and adolescents is on the rise globally. Affected children are prone to cardio-metabolic problems later in life, especially hypertension. The prevalence of obesity/overweight may differ depending on school type. Private schools are attended mostly by children of the affluent, while public schools are attended predominantly by those in the low and middle socio-economic classes. To compare the prevalence of overweight, obesity and elevated blood pressure (BP) in pupils attending public and private primary schools in an urban community in Nigeria. In this cross sectional study, the BMI and BP of pupils in public and private primary schools, recruited by multistage sampling method, were measured. Their nutritional status was categorized using their BMI percentiles. Analysis was by SPSS. A total of 1466 pupils were recruited, 814(55.5%) were in public schools and 722(49.2%) were males. The prevalence of overweight and obesity was higher in private schools 11.8% and 11.7% compared to public schools 3.3% and 0.9%. The mean systolic BP of pupils in public schools 96.8 ± 12.5 mmHg was higher than that in private schools 95.5 ± 10.2 mmHg, p = 0.032. Distribution of pupils with prehypertension and hypertension between private and public schools was not significantly different. The prevalence of overweight and obesity is higher in pupils attending private schools compared to those in public school. Urgent measures are needed to stem this tide through education, weight reduction and physical activity programs, especially in pupils attending private schools.

  8. Final Report: Archiving Data to Support Data Synthesis of DOE Sponsored Elevated CO2 Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Megonigal, James [Smithsonian Environmental Research Center, Edgewater, MD (United States); Lu, Meng [Smithsonian Environmental Research Center, Edgewater, MD (United States)

    2017-09-05

    Over the last three decades DOE made a large investment in field-scale experiments in order to understand the role of terrestrial ecosystems in the global carbon cycle, and forecast how carbon cycling will change over the next century. The Smithsonian Environmental Research Center received one of the first awards in this program and managed two long-term studies (25 years and 10 years) with a total of approximately $10 million of support from DOE, and many more millions leveraged from the Smithsonian Institution and agencies such as NSF. The present DOE grant was based on the premise that such a large investment demands a proper synthesis effort so that the full potential of these experiments are realized through data analysis and modeling. The goal of the this grant was to archive legacy data from two major elevated carbon dioxide experiments in DOE databases, and to engage in synthesis activities using these data. Both goals were met. All datasets deemed a high priority for data synthesis and modeling were prepared for archiving and analysis. Many of these datasets were deposited in DOE’s CDIAC, while others are being held at the Oak Ridge National Lab and the Smithsonian Institution until they can be received by DOE’s new ESS-DIVE system at Berkeley Lab. Most of the effort was invested in researching and re-constituting high-quality data sets from a 30-year elevated CO2 experiment. Using these data, the grant produced products that are already benefiting climate change science, including the publication of new coastal wetland allometry equations based on 9,771 observations, public posting of dozens of datasets, metadata and supporting codes from long-term experiments at the Global Change Research Wetland, and publication of two synthetic data papers on scrub oak forest responses to elevated CO2. In addition, three papers are in review or nearing submission reporting unexpected long-term patterns in ecosystem responses to elevated CO

  9. Direct numerical simulations of temporally developing hydrocarbon shear flames at elevated pressure: effects of the equation of state and the unity Lewis number assumption

    Science.gov (United States)

    Korucu, Ayse; Miller, Richard

    2016-11-01

    Direct numerical simulations (DNS) of temporally developing shear flames are used to investigate both equation of state (EOS) and unity-Lewis (Le) number assumption effects in hydrocarbon flames at elevated pressure. A reduced Kerosene / Air mechanism including a semi-global soot formation/oxidation model is used to study soot formation/oxidation processes in a temporarlly developing hydrocarbon shear flame operating at both atmospheric and elevated pressures for the cubic Peng-Robinson real fluid EOS. Results are compared to simulations using the ideal gas law (IGL). The results show that while the unity-Le number assumption with the IGL EOS under-predicts the flame temperature for all pressures, with the real fluid EOS it under-predicts the flame temperature for 1 and 35 atm and over-predicts the rest. The soot mass fraction, Ys, is only under-predicted for the 1 atm flame for both IGL and real gas fluid EOS models. While Ys is over-predicted for elevated pressures with IGL EOS, for the real gas EOS Ys's predictions are similar to results using a non-unity Le model derived from non-equilibrium thermodynamics and real diffusivities. Adopting the unity Le assumption is shown to cause misprediction of Ys, the flame temperature, and the mass fractions of CO, H and OH.

  10. 77 FR 1060 - High Pressure Steel Cylinders From the People's Republic of China: Postponement of Final...

    Science.gov (United States)

    2012-01-09

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-977] High Pressure Steel... (``Department'') initiated an antidumping duty investigation on high pressure steel cylinders from the People's... investigation is currently due 75 days after the date of the Preliminary Determination.\\3\\ \\1\\ See High Pressure...

  11. 77 FR 26738 - High Pressure Steel Cylinders From the People's Republic of China: Final Affirmative...

    Science.gov (United States)

    2012-05-07

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-978] High Pressure Steel... producers and exporters of high pressure steel cylinders (steel cylinders) from the People's Republic of... The following events have occurred since the Preliminary Determination.\\1\\ \\1\\ See High Pressure Steel...

  12. Development of fast-burn combustion with elevated coolant temperatures for natural gas engines. Final report, May 1985-May 1990

    Energy Technology Data Exchange (ETDEWEB)

    Bruch, K.L.; Dennis, J.W.

    1990-09-01

    The overall objective of the work was to improve the state of the art in the gas fired spark ignited engine for use in a cogeneration system. Four characteristics were enhanced for cogeneration, namely, Low Pressure Gas Induction, Improved Shaft Thermal Efficiency, Low NOx Emissions, and Increased Jacket Coolant Temperature. Using Taguchi methods and statistical design of experiment methodologies, an engine design evolved that exhibited: The ability to run satisfactorily on supply gas pressure as low as 1.5 psig (goal: 1 psig); A brake specific fuel consumption as low as 6950 Btu/hp-hr (36.6% thermal efficiency) at 2 gm/hp-hr NOx (goal: 7000 acceptable, 6800 excellent with NOx no more than 2 gm/hp-hr); A jacket water coolant system (with oil cooler on the same circuit) temperature of 225 F (goal); and The ability to burn gas with Methane Number as low as 67 (goal).

  13. FINAL REPORT - Development of High Pressure Hydrogen Storage Tank for Storage and Gaseous Truck Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, Donald [Hexagon Lincoln LLC, Lincoln, NE (United States)

    2017-08-04

    $575/kg H2 delivered. [Based on product pricing in 1Q2017.] Emphasis was placed on configuration of larger capacity systems within the vehicle weights and dimensions allowed on federal and state highways in the United States and other countries. These activities resulted in the design and development of integrated tube trailer systems that have increased delivery capacities by 45%. The hydrogen delivery capacity of our largest system is 845 kg, exceeding the project’s 2015 target of 700 kg H2 delivered. Emerging technologies offering improvement of the safety systems used on the equipment were investigated, with particular focus on improving the reliability and cost of the emergency venting system for fire protection. Finally, investment in our materials laboratory improved detection and characterization of hydrogen-induced damage in polymer materials, supporting the development of operational protocols to avoid damage to pressure vessel liners and valve components.

  14. Final Report of the National Black Health Providers Task Force on High Blood Pressure Education and Control.

    Science.gov (United States)

    Public Health Service (DHHS), Rockville, MD.

    This is the final report of National Black Health Providers Task Force (NBHPTF) on High Blood Pressure Education and Control. The first chapter of the report recounts the history of the NBHPTF and its objectives. In the second chapter epidemiological evidence is presented to demonstrate the need for a suggested 20 year plan aimed at controlling…

  15. Factors associated with elevated blood pressure or hypertension in Afro-Caribbean youth: a cross-sectional study.

    Science.gov (United States)

    Ferguson, Trevor S; Younger-Coleman, Novie O M; Tulloch-Reid, Marshall K; Bennett, Nadia R; Rousseau, Amanda E; Knight-Madden, Jennifer M; Samms-Vaughan, Maureen E; Ashley, Deanna E; Wilks, Rainford J

    2018-01-01

    Although several studies have identified risk factors for high blood pressure (BP), data from Afro-Caribbean populations are limited. Additionally, less is known about how putative risk factors operate in young adults and how social factors influence the risk of high BP. In this study, we estimated the relative risk for elevated BP or hypertension (EBP/HTN), defined as BP ≥ 120/80 mmHg, among young adults with putative cardiovascular disease (CVD) risk factors in Jamaica and evaluated whether relative risks differed by sex. Data from 898 young adults, 18-20 years old, were analysed. BP was measured with a mercury sphygmomanometer after participants had been seated for 5 min. Anthropometric measurements were obtained, and glucose, lipids and insulin measured from a fasting venous blood sample. Data on socioeconomic status (SES) were obtained via questionnaire. CVD risk factor status was defined using standard cut-points or the upper quintile of the distribution where the numbers meeting standard cut-points were small. Relative risks were estimated using odds ratios (OR) from logistic regression models. Prevalence of EBP/HTN was 30% among males and 13% among females ( p  women, high triglycerides (OR 1.98, CI [1.03-3.81], p  = 0.040) and high HOMA-IR (OR 2.07, CI [1.03-4.12], p  = 0.039) were positively associated with EBP/HTN. Lower SES was also associated with higher odds for EBP/HTN (OR 4.63, CI [1.31-16.4], p  = 0.017, for moderate vs. high household possessions; OR 2.61, CI [0.70-9.77], p  = 0.154 for low vs. high household possessions). Alcohol consumption was associated with lower odds of EBP/HTN among females only; OR 0.41 (CI [0.18-0.90], p  = 0.026) for drinking women lower SES was positively associated with EBP/HTN, while moderate alcohol consumption was associated lower odds of EBP/HTN.

  16. Elevated central venous pressure is associated with impairment of microcirculatory blood flow in sepsis: a hypothesis generating post hoc analysis

    NARCIS (Netherlands)

    Vellinga, Namkje A. R.; Ince, C.; Boerma, E. C.

    2013-01-01

    Microcirculatory driving pressure is defined as the difference between post-arteriolar and venular pressure. In previous research, an absence of correlation between mean arterial blood pressure (MAP) and microcirculatory perfusion has been observed. However, the microcirculation may be considered as

  17. Association between Selective Beta-adrenergic Drugs and Blood Pressure Elevation: Data Mining of the Japanese Adverse Drug Event Report (JADER) Database.

    Science.gov (United States)

    Ohyama, Katsuhiro; Inoue, Michiko

    2016-01-01

    Selective beta-adrenergic drugs are used clinically to treat various diseases. Because of imperfect receptor selectivity, beta-adrenergic drugs cause some adverse drug events by stimulating other adrenergic receptors. To examine the association between selective beta-adrenergic drugs and blood pressure elevation, we reviewed the Japanese Adverse Drug Event Reports (JADERs) submitted to the Japan Pharmaceuticals and Medical Devices Agency. We used the Medical Dictionary for Regulatory Activities (MedDRA) Preferred Terms extracted from Standardized MedDRA queries for hypertension to identify events related to blood pressure elevation. Spontaneous adverse event reports from April 2004 through May 2015 in JADERs, a data mining algorithm, and the reporting odds ratio (ROR) were used for quantitative signal detection, and assessed by the case/non-case method. Safety signals are considered significant if the ROR estimates and lower bound of the 95% confidence interval (CI) exceed 1. A total of 2021 reports were included in this study. Among the nine drugs examined, significant signals were found, based on the 95%CI for salbutamol (ROR: 9.94, 95%CI: 3.09-31.93) and mirabegron (ROR: 7.52, 95%CI: 4.89-11.55). The results of this study indicate that some selective beta-adrenergic drugs are associated with blood pressure elevation. Considering the frequency of their indications, attention should be paid to their use in elderly patients to avoid adverse events.

  18. Blood Pressure Elevation Associated with Topical Prostaglandin F2α Analogs: An Analysis of the Different Spontaneous Adverse Event Report Databases.

    Science.gov (United States)

    Ohyama, Katsuhiro; Kawakami, Haruna; Inoue, Michiko

    2017-01-01

    Topical prostaglandin F2α (PGF2α) analogs are widely used as the first line of therapy for glaucoma. Systemic PGF2α is suggested to increase blood pressure. Some ophthalmic formulations with β-receptor blocking or α-receptor stimulating actions are reported to cause systemic adverse events such as a decrease in heart rate and blood pressure. The objective of this study was to evaluate the association between topical PGF2α analogs and blood pressure elevation. We analyzed the reports obtained from the Food and Drug Administration Adverse Event Reporting System (FAERS) database from the first quarter of 2004 until the end of 2015 and the Japanese Adverse Drug Event Report (JADER) database from April 2004 to January 2016 for signal detection using reporting odds ratio (ROR), a method of disproportionality analyses. Signals are considered significant if the ROR estimates and lower bound of the 95% confidence interval (CI) exceed 1. Preferred terms in the Medical Dictionary for Regulatory Activities were utilized to define blood pressure elevation. A total of 6156081 reports from the FAERS and 351226 reports from the JADER were analyzed. The significant RORs with 95% CI were calculated to be 1.82 (95% CI: 1.55-2.13) for bimatoprost, 1.69 (95% CI: 1.53-1.85) for latanoprost, and 2.17 (95% CI: 1.82-2.59) for travoprost from the FAERS. From the JADER, 5.01 (95% CI: 1.59-15.8) was calculated for bimatoprost and 8.02 (95% CI: 2.94-21.9) for tafluprost. The resulting data suggest the necessity for further clinical research on blood pressure elevation associated with topical PGF2α analogs and close monitoring.

  19. [The affect of Erigeron Breviscapus (Vant.) Hand-Mazz on axoplasmic transport of optic nerve in rats with experimentally elevated intraocular pressure].

    Science.gov (United States)

    Zhu, Y; Jiang, Y; Liu, Z; Luo, X; Wu, Z

    2000-07-01

    To investigate whether Erigeron Breviscapus (Vant.) Hand-Mazz (EBHM) can improve the optic nerve axoplasmic transport in rats with experimentally elevated intraocular pressure (IOP). Thirty healthy SD rats were used for the study, acute elevated IOP model in the right eye was built, then they were divided into three groups randomly: Group A (0 day group) included six rats for retinal ganglion cell (RGC) counting via left superior colliculus retrograde horse radish perokidase labeling; Group B, twelve rats divided into EBHM treatment group and control group (6 rats in each subgroup) for RGC counting via left superior colliculus retrograde labeling after twenty days, and Group C included twelve rats submitted the same treatment and procedure as group B after 40 days. After 0 day of acute elevated IOP, no labeled RGCs were observed. After twenty days of acute elevated IOP, in the control and EBHM subgroups the density of labeled RGCs were (423 +/- 220)/mm(2) and (749 +/- 294)/mm(2) respectively, the difference between two subgroups showed statistical significance (P < 0.01). After 40 days of acute elevated IOP, the density of RGCs in the control and EBHM subgroups in group C were (610 +/- 315)/mm(2) and (1,048 +/- 393)/mm(2) respectively, the difference between the two subgroups being statistically significant (P < 0.01). After 20 days and 40 days of acute elevation of IOP, the density of RGCs is obviously higher in EBHM group than that in the control group. It is revealed that EBHM can improve the optic nerve axoplasmic transportation blocked by acute elevation of IOP in rats.

  20. Final Technical Report: Response of Mediterranean-Type Ecosystems to Elevated Atmospheric CO2 and Associated Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Oechel, Walter C

    2002-08-15

    This research incorporated an integrated hierarchical approach in space, time, and levels of biological/ecological organization to help understand and predict ecosystem response to elevated CO{sub 2} and concomitant environmental change. The research utilized a number of different approaches, and collaboration of both PER and non-PER investigators to arrive at a comprehensive, integrative understanding. Central to the work were the CO{sub 2}-controlled, ambient Lit, Temperature controlled (CO{sub 2}LT) null-balance chambers originally developed in the arctic tundra, which were re-engineered for the chaparral with treatment CO{sub 2} concentrations of from 250 to 750 ppm CO{sub 2} in 100 ppm increments, replicated twice to allow for a regression analysis. Each chamber was 2 meters on a side and 2 meters tall, which were installed over an individual shrub reprouting after a fire. This manipulation allowed study of the response of native chaparral to varying levels of CO{sub 2}, while regenerating from an experimental burn. Results from these highly-controlled manipulations were compared against Free Air CO{sub 2} Enrichment (FACE) manipulations, in an area adjacent to the CO{sub 2}LT null balance greenhouses. These relatively short-term results (5-7 years) were compared to long-term results from Mediterranean-type ecosystems (MTEs) surrounding natural CO{sub 2} springs in northern Italy, near Laiatico, Italy. The springs lack the controlled experimental rigor of our CO{sub 2}LT and FACE manipulation, but provide invaluable validation of our long-term predictions.

  1. Factors associated with elevated blood pressure or hypertension in Afro-Caribbean youth: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Trevor S. Ferguson

    2018-02-01

    Full Text Available Background Although several studies have identified risk factors for high blood pressure (BP, data from Afro-Caribbean populations are limited. Additionally, less is known about how putative risk factors operate in young adults and how social factors influence the risk of high BP. In this study, we estimated the relative risk for elevated BP or hypertension (EBP/HTN, defined as BP ≥ 120/80 mmHg, among young adults with putative cardiovascular disease (CVD risk factors in Jamaica and evaluated whether relative risks differed by sex. Methods Data from 898 young adults, 18–20 years old, were analysed. BP was measured with a mercury sphygmomanometer after participants had been seated for 5 min. Anthropometric measurements were obtained, and glucose, lipids and insulin measured from a fasting venous blood sample. Data on socioeconomic status (SES were obtained via questionnaire. CVD risk factor status was defined using standard cut-points or the upper quintile of the distribution where the numbers meeting standard cut-points were small. Relative risks were estimated using odds ratios (OR from logistic regression models. Results Prevalence of EBP/HTN was 30% among males and 13% among females (p < 0.001 for sex difference. There was evidence for sex interaction in the relationship between EBP/HTN and some of risk factors (obesity and household possessions, therefore we report sex-specific analyses. In multivariable logistic regression models, factors independently associated with EBP/HTN among men were obesity (OR 8.48, 95% CI [2.64–27.2], p < 0.001, and high glucose (OR 2.01, CI [1.20–3.37], p = 0.008, while high HOMA-IR did not achieve statistical significance (OR 2.08, CI [0.94–4.58], p = 0.069. In similar models for women, high triglycerides (OR 1.98, CI [1.03–3.81], p = 0.040 and high HOMA-IR (OR 2.07, CI [1.03–4.12], p = 0.039 were positively associated with EBP/HTN. Lower SES was also associated with higher odds for

  2. Final report on the reactor pressure vessel pressurized-thermal-shock. International comparative assessment study (RPV PTS ICAS)

    International Nuclear Information System (INIS)

    Sievers, J.; Schulz, H.; Bass, R.; Pugh, C.

    1999-10-01

    A summary of the recently completed International Comparative Assessment Study of Pressurized-Thermal-Shock in Reactor Pressure Vessels (RPV PTS ICAS) is presented here to record the results in actual and comparative fashions. Within the DFM task, where account was taken of material properties and boundary conditions, reasonable agreement was obtained in linear-elastic and elastic-plastic analysis results. Linear elastic analyses and J-estimation schemes were shown to provide conservative estimates of peak crack driving force when compared with those obtained using complex three-dimensional (3D) finite element analyses. Predictions of RT NDT generally showed less scatter than that observed in crack driving force calculations due to the fracture toughness curve used for fracture assessment in the transition temperature region. Observed scatter in some analytical results could be traced mainly to a misinterpretation of the thermal expansion coefficient data given for the cladding and base metal. Also, differences in some results could be due to a quality assurance problem related to procedures for approximating the loading data given in the Problem Statement. For the PFM task, linear-elastic solutions were again shown to be conservative with respect to elastic-plastic solutions (by a factor of 2 to 4). Scatter in solutions obtained using the same computer code was generally attributable to differences in input parameters, e.g. standard deviations for the initial value of RT NDT , as well as for nickel and copper content. In the THM task, while there was a high degree of scatter during the early part of the transient, reasonable agreement in results was obtained during the latter part of the transient. Generally, the scatter was due to differences in analytical approaches used by participants, which included correlation-based engineering methods, system codes and three-dimensional computational fluids dynamics codes. Some of the models used to simulate condensation

  3. Elevating your elevator talk

    Science.gov (United States)

    An important and often overlooked item that every early career researcher needs to do is compose an elevator talk. The elevator talk, named because the talk should not last longer than an average elevator ride (30 to 60 seconds), is an effective method to present your research and yourself in a clea...

  4. Early response of pressurized hot water in a pipe to a sudden break. Final report

    International Nuclear Information System (INIS)

    Alamgir, M.; Kan, C.Y.; Lienhard, J.H.

    1981-06-01

    Experimental and analytic studies that explain the details of early pressure variations during rapid depressurization in water-cooled reactors are presented as a means of assessing sudden break consequences in a coolant pipe. The report includes (1) a description of the experiment, (2) an analysis of the new bubble growth law for thermally controlled growth of vapor bubbles in an exponentially-varying pressure field, and (3) a review of previous studies and additional observations of blowdown behavior

  5. Barometric pressure transient testing applications at the Nevada Test Site: formation permeability analysis. Final report

    International Nuclear Information System (INIS)

    Hanson, J.M.

    1984-12-01

    The report evaluates previous investigations of the gas permeability of the rock surrounding emplacement holes at the Nevada Test Site. The discussion sets the framework from which the present uncertainty in gas permeability can be overcome. The usefulness of the barometric pressure testing method has been established. Flow models were used to evaluate barometric pressure transients taken at NTS holes U2fe, U19ac and U20ai. 31 refs., 103 figs., 18 tabs

  6. Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Oechel, W.C.

    1996-11-01

    The overall objective of this research was to document current patterns of CO{sub 2} flux in selected locations of the circumpolar arctic, and to develop the information necessary to predict how these fluxes may be affected by climate change. In fulfillment of these objectives, net CO{sub 2} flux was measured at several sites on the North Slope of Alaska during the 1990--94 growing season (June--August) to determine the local and regional patterns of seasonal CO{sub 2} exchange. In addition, net CO{sub 2} flux was measured in the Russian and Icelandic Arctic to determine if the patterns of CO{sub 2} exchange observed in Arctic Alaska were representative of the circumpolar Arctic, while cold-season CO{sub 2} flux measurements were carried out during the 1993--94 winter season to determine the magnitude of CO{sub 2} efflux not accounted for by the growing season measurements. Manipulations of soil water table depth and surface temperature, which were identified from the extensive measurements as being the most important variables in determining the magnitude and direction of net CO{sub 2} exchange, were carried out during the 1993--94 growing seasons in tussock and wet sedge tundra ecosystems. Finally, measurements of CH{sub 4} flux were also measured at several of the North Slope study sites during the 1990--91 growing seasons.

  7. Blood Pressure Out of the Office: Its Time Has Finally Come.

    Science.gov (United States)

    Krakoff, Lawrence R

    2016-03-01

    The diagnosis of hypertension includes measurement of blood pressure out of the office by either 24-hour ambulatory monitoring or home blood pressure monitoring. These methods have led to recognition of "white coat hypertension" (WCH) and "masked hypertension" (MH). Research in the 1930s first demonstrated that blood pressures in the office were often far different from those out of the office, at a time when there was no effective treatment. International attention was focused on another imminent world war and a highly controversial election in the United States. Hypertension was not a priority for concern. From the 1950s onward: (i) epidemiology linked hypertension to risk of cardiovascular disease, (ii) effective and safe drugs for treatment of hypertension appeared, (iii) randomized clinical trials demonstrated that drug treatment of hypertension is highly effective for prevention of cardiovascular disease, and (iv) advances in technology led to development of small, portable devices for recording blood pressure noninvasively at home or during usual activities. Accurate measurement of blood pressure in "real life" is now necessary and feasible for appropriate diagnosis and assessment of treatment. Out-of-office blood pressure measurement is emerging as the standard of care for hypertension. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Response of a tundra ecosytem to elevated atmospheric carbon dioxide and CO2-induced climate change. Final report

    International Nuclear Information System (INIS)

    Oechel, W.C.

    1996-11-01

    The overall objective of this research was to document current patterns of CO 2 flux in selected locations of the circumpolar arctic, and to develop the information necessary to predict how these fluxes may be affected by climate change. In fulfillment of these objectives, net CO 2 flux was measured at several sites on the North Slope of Alaska during the 1990-94 growing season (June-August) to determine the local and regional patterns, of seasonal CO 2 exchange. In addition, net CO 2 flux was measured in the Russian and Icelandic Arctic to determine if the patterns of CO 2 exchange observed in Arctic Alaska were representative of the circumpolar arctic, while cold-season CO 2 flux measurements were carried out during the 1993-94 winter season to determine the magnitude of CO 2 efflux not accounted for by the growing season measurements. Manipulations of soil water table depth and surface temperature, which were identified from the extensive measurements as being the most important variables in determining the magnitude and direction of net CO 2 exchange, were carried out during the 1993-94 growing seasons in tussock and wet sedge tundra ecosystems. Finally, measurements of CH 4 flux were also measured at several of the North Slope study sites during the 1990-91 growing seasons. Measurements were made on small (e.g. 0.5 m 2 ) plots using a portable gas-exchange system and cuvette. The sample design allowed frequent measurements of net CO 2 exchange and respiration over diurnal and seasonal cycles, and a large spatial extent that incorporated both locally and regionally diverse tundra surface types. Measurements both within and between ecosystem types typically extended over soil water table depth and temperature gradients, allowing for the indirect analysis of the effects of anticipated climate change scenarios on net CO 2 exchange. In situ experiments provided a direct means for testing hypotheses

  9. Vapor-Liquid Phase Equilibria for Carbon Dioxide-I- Isopentanol Binary System at Elevated Pressure%Vapor-Liquid Phase Equilibria for Carbon Dioxide-I- Isopentanol Binary System at Elevated Pressure

    Institute of Scientific and Technical Information of China (English)

    王琳; 曹丰璞; 刘珊珊; 杨浩

    2011-01-01

    High-pressure vapor-liquid phase equilibrium data for carbon dioxide+ isopentanol were measured at tempera- tures of 313.2, 323.1, 333.5 and 343.4 K in the pressure range of 4.64 to 12.71 MPa in a variable-volume high-pressure visual cell. The experimental data were well correlated with Peng-Robinson equation of state (PR-EOS) together with van der Waals-2 two-parameter mixing rule, and the binary interaction parameters were obtained. Henry coefficients and partial molar volumes of CO2 at infinite dilution were estimated based on Krichevsky-Kasarnovsky equation, and Henry coefficients increase with increasing temperature, however, partial molar volumes of CO2 at infinite dilution are negative and the magnitudes decrease with temperature.

  10. Response of a tundra ecosytem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Oechel, W.C.

    1996-11-01

    The overall objective of this research was to document current patterns of CO{sub 2} flux in selected locations of the circumpolar arctic, and to develop the information necessary to predict how these fluxes may be affected by climate change. In fulfillment of these objectives, net CO{sub 2} flux was measured at several sites on the North Slope of Alaska during the 1990-94 growing season (June-August) to determine the local and regional patterns, of seasonal CO{sub 2} exchange. In addition, net CO{sub 2} flux was measured in the Russian and Icelandic Arctic to determine if the patterns of CO{sub 2} exchange observed in Arctic Alaska were representative of the circumpolar arctic, while cold-season CO{sub 2} flux measurements were carried out during the 1993-94 winter season to determine the magnitude of CO{sub 2} efflux not accounted for by the growing season measurements. Manipulations of soil water table depth and surface temperature, which were identified from the extensive measurements as being the most important variables in determining the magnitude and direction of net CO{sub 2} exchange, were carried out during the 1993-94 growing seasons in tussock and wet sedge tundra ecosystems. Finally, measurements of CH{sub 4} flux were also measured at several of the North Slope study sites during the 1990-91 growing seasons. Measurements were made on small (e.g. 0.5 m{sup 2}) plots using a portable gas-exchange system and cuvette. The sample design allowed frequent measurements of net CO{sub 2} exchange and respiration over diurnal and seasonal cycles, and a large spatial extent that incorporated both locally and regionally diverse tundra surface types. Measurements both within and between ecosystem types typically extended over soil water table depth and temperature gradients, allowing for the indirect analysis of the effects of anticipated climate change scenarios on net CO{sub 2} exchange. In situ experiments provided a direct means for testing hypotheses.

  11. Species composition, elevation, and former management type affect browsing pressure on forest regeneration in the Tatra National Park

    Directory of Open Access Journals (Sweden)

    Bodziarczyk Jan

    2017-06-01

    Full Text Available Effects of ungulate pressure on the development of young generation of trees is one of the most important issues in ecology and forestry. Ungulate pressure influence on the development of natural regeneration has been also reported from several national parks. Our study on the effects of ungulate browsing on the young generation of trees was conducted on more than 500 sample plots controlled during one growing season.

  12. Cerebral blood flow changes in response to elevated intracranial pressure in rabbits and bluefish: a comparative study.

    Science.gov (United States)

    Beiner, J M; Olgivy, C S; DuBois, A B

    1997-03-01

    In mammals, the cerebrovascular response to increases in intracranial pressure may take the form of the Cushing response, which includes increased mean systemic arterial pressure, bradycardia and diminished respirations. The mechanism, effect and value of these responses are debated. Using laser-Doppler flowmetry to measure cerebral blood flow, we analyzed the cardiovascular responses to intracranial pressure raised by epidural infusion of mock cerebrospinal fluid in the bluefish and in the rabbit, and compare the results. A decline in cerebral blood flow preceding a rise in mean systemic arterial pressure was observed in both species. Unlike bluefish, rabbits exhibit a threshold of intracranial pressure below which cerebral blood flow was maintained and no cardiovascular changes were observed. The difference in response between the two species was due to the presence of an active autoregulatory system in the cerebral tissue of rabbits and its absence in bluefish. For both species studied, the stimulus for the Cushing response seems to be a decrement in cerebral blood flow. The resulting increase in the mean systemic arterial pressure restores cerebral blood flow to levels approaching controls.

  13. Seed storage at elevated partial pressure of oxygen, a fast method for analysing seed ageing under dry conditions

    Science.gov (United States)

    Groot, S. P. C.; Surki, A. A.; de Vos, R. C. H.; Kodde, J.

    2012-01-01

    Background and Aims Despite differences in physiology between dry and relative moist seeds, seed ageing tests most often use a temperature and seed moisture level that are higher than during dry storage used in commercial practice and gene banks. This study aimed to test whether seed ageing under dry conditions can be accelerated by storing under high-pressure oxygen. Methods Dry barley (Hordeum vulgare), cabbage (Brassica oleracea), lettuce (Lactuca sativa) and soybean (Glycine max) seeds were stored between 2 and 7 weeks in steel tanks under 18 MPa partial pressure of oxygen. Storage under high-pressure nitrogen gas or under ambient air pressure served as controls. The method was compared with storage at 45 °C after equilibration at 85 % relative humidity and long-term storage at the laboratory bench. Germination behaviour, seedling morphology and tocopherol levels were assessed. Key Results The ageing of the dry seeds was indeed accelerated by storing under high-pressure oxygen. The morphological ageing symptoms of the stored seeds resembled those observed after ageing under long-term dry storage conditions. Barley appeared more tolerant of this storage treatment compared with lettuce and soybean. Less-mature harvested cabbage seeds were more sensitive, as was the case for primed compared with non-primed lettuce seeds. Under high-pressure oxygen storage the tocopherol levels of dry seeds decreased, in a linear way with the decline in seed germination, but remained unchanged in seeds deteriorated during storage at 45 °C after equilibration at 85 % RH. Conclusions Seed storage under high-pressure oxygen offers a novel and relatively fast method to study the physiology and biochemistry of seed ageing at different seed moisture levels and temperatures, including those that are representative of the dry storage conditions as used in gene banks and commercial practice. PMID:22967856

  14. Seed storage at elevated partial pressure of oxygen, a fast method for analysing seed ageing under dry conditions.

    Science.gov (United States)

    Groot, S P C; Surki, A A; de Vos, R C H; Kodde, J

    2012-11-01

    Despite differences in physiology between dry and relative moist seeds, seed ageing tests most often use a temperature and seed moisture level that are higher than during dry storage used in commercial practice and gene banks. This study aimed to test whether seed ageing under dry conditions can be accelerated by storing under high-pressure oxygen. methods: Dry barley (Hordeum vulgare), cabbage (Brassica oleracea), lettuce (Lactuca sativa) and soybean (Glycine max) seeds were stored between 2 and 7 weeks in steel tanks under 18 MPa partial pressure of oxygen. Storage under high-pressure nitrogen gas or under ambient air pressure served as controls. The method was compared with storage at 45 °C after equilibration at 85 % relative humidity and long-term storage at the laboratory bench. Germination behaviour, seedling morphology and tocopherol levels were assessed. The ageing of the dry seeds was indeed accelerated by storing under high-pressure oxygen. The morphological ageing symptoms of the stored seeds resembled those observed after ageing under long-term dry storage conditions. Barley appeared more tolerant of this storage treatment compared with lettuce and soybean. Less-mature harvested cabbage seeds were more sensitive, as was the case for primed compared with non-primed lettuce seeds. Under high-pressure oxygen storage the tocopherol levels of dry seeds decreased, in a linear way with the decline in seed germination, but remained unchanged in seeds deteriorated during storage at 45 °C after equilibration at 85 % RH. Seed storage under high-pressure oxygen offers a novel and relatively fast method to study the physiology and biochemistry of seed ageing at different seed moisture levels and temperatures, including those that are representative of the dry storage conditions as used in gene banks and commercial practice.

  15. Elevated hydrostatic pressures induce apoptosis and oxidative stress through mitochondrial membrane depolarization in PC12 neuronal cells: A cell culture model of glaucoma.

    Science.gov (United States)

    Tök, Levent; Nazıroğlu, Mustafa; Uğuz, Abdülhadi Cihangir; Tök, Ozlem

    2014-10-01

    Despite the importance of oxidative stress and apoptosis through mitochondrial depolarization in neurodegenerative diseases, their roles in etiology of glaucoma are poorly understood. We aimed to investigate whether oxidative stress and apoptosis formation are altered in rat pheochromocytoma-derived cell line-12 (PC12) neuronal cell cultures exposed to elevated different hydrostatic pressures as a cell culture model of glaucoma. Cultured PC12 cells were subjected to 0, 15 and 70 mmHg hydrostatic pressure for 1 and 24 h. Then, the following values were analyzed: (a) cell viability; (b) lipid peroxidation and intracellular reactive oxygen species production; (c) mitochondrial membrane depolarization; (d) cell apoptosis; (e) caspase-3 and caspase-9 activities; (f) reduced glutathione (GSH) and glutathione peroxidase (GSH-Px). The hydrostatic pressures (15 and 70 mmHg) increased oxidative cell damage through a decrease of GSH and GSH-Px values, and increasing mitochondrial membrane potential. Additionally, 70 mmHg hydrostatic pressure for 24 h indicated highest apoptotic effects, as demonstrated by plate reader analyses of apoptosis, caspase-3 and -9 values. The present data indicated oxidative stress, apoptosis and mitochondrial changes in PC12 cell line during different hydrostatic pressure as a cell culture model of glaucoma. This findings support the view that mitochondrial oxidative injury contributes early to glaucomatous optic neuropathy.

  16. Novel Bioconjugation Strategy Using Elevated Hydrostatic Pressure: A Case Study for the Site-Specific Attachment of Polyethylene Glycol (PEGylation) of Recombinant Human Ciliary Neurotrophic Factor.

    Science.gov (United States)

    Wang, Qi; Zhang, Chun; Guo, Fangxia; Li, Zenglan; Liu, Yongdong; Su, Zhiguo

    2017-11-15

    In this paper, we reported a novel strategy for the site-specific attachment of polyethylene glycol (PEGylation) of proteins using elevated hydrostatic pressure. The process was similar to the conventional one except the reactor was under elevated hydrostatic pressure. The model protein was recombinant human ciliary neurotrophic factor (rhCNTF), and the reagent was monomethoxy-polyethylene glycol-maleimide (mPEG-MAL). PEGylation with mPEG (40 kDa)-MAL at pH 7.0 under normal pressure for 5 h achieved a less than 5% yield. In comparison, when the pressure was elevated, the PEGylation yield was increased dramatically, reaching nearly 90% at 250 MPa. Furthermore, the following phenomena were observed: (1) high-hydrostatic-pressure PEGylation (HHPP) could operate at a low reactant ratio of 1:1.2 (rhCNTF to mPEG-MAL), while the conventional process needs a much-higher ratio. (2) Short and long chains of PEG gave a similar yield of 90% in HHPP, while the conventional yield for the short chain of the PEG was higher than that of the long chain. (3) The reaction pH in the range of 7.0 to 8.0 had almost no influence upon the yield of HHPP, while the PEGylation yield was significantly increased by a factor of three from pH 7.0 to 8.0 at normal pressure. Surface accessibility analysis was performed using GRASP2 software, and we found that Cys17 of rhCNTF was located at the concave patches, which may have steric hindrance for the PEG to approach. The speculated benefit of HHPP was the facilitation of target-site exposure, reducing the steric hindrance and making the reaction much easier. Structure and activity analysis demonstrated that the HHPP product was comparable to the PEGylated rhCNTF prepared through a conventional method. Overall, this work demonstrated that HHPP, as we proposed, may have application potentials in various conjugations of biomacromolecules.

  17. Numerically induced pressure excursions in two-phase-flow calculations. Final report

    International Nuclear Information System (INIS)

    Mahaffy, J.H.; Liles, D.R.

    1983-01-01

    Pressure spikes that cannot be traced to any physical origin sometimes are observed when standard Eulerian finite-difference methods are used to calculate two-phase-flow transients. This problem occurs with varying frequency in nuclear reactor safety codes such as RELAP, RETRAN, COBRA, and TRAC. These spikes usually result from numerical water packing or from interactions between spatial discretization and heat transfer

  18. SEPARATION OF HAZARDOUS ORGANICS BY LOW PRESSURE REVERSE OSMOSIS MEMBRANES - PHASE II FINAL REPORT

    Science.gov (United States)

    Extensive experimental studies showed that thin-film, composite membranes can be used effectively for the separation of selected hazardous organic compounds. This waste treatment technique offers definite advantages in terms of high solute separations at low pressures (<2MPa) and...

  19. The Specialist Committee on Cavitation Induced Pressures, Final Report and Recommendations to the 23rd ITTC

    DEFF Research Database (Denmark)

    Friesch, J.; Kim, K.-H.; Andersen, Poul

    2002-01-01

    General Technical Conclusions Propeller-excited hull pressure fluctuations are strongly influenced by intermittence of sheet cavitation, the dynamics of tip vortex cavitation, and the statistical properties of the cavitation. On modern propellers, tip vortex cavitation may be even more important ...

  20. Acoustic nonlinearity parameter B/A determined by means of thermodynamic method under elevated pressures for alkanediols.

    Science.gov (United States)

    Zorębski, Edward; Zorębski, Michał

    2014-01-01

    The so-called Beyer nonlinearity parameter B/A is calculated for 1,2- and 1,3-propanediol, 1,2-, 1,3-, and 1,4-butanediol, as well as 2-methyl-2,4-pentanediol by means of a thermodynamic method. The calculations are made for temperatures from (293.15 to 318.15) K and pressures up to 100 MPa. The decrease in B/A values with the increasing pressure is observed. In the case of 1,3-butanediol, the results are compared with corresponding literature data. The consistency is very satisfactory. A simple relationship between the internal pressure and B/A nonlinearity parameter has also been studied. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Drinking Water Sodium and Elevated Blood Pressure of Healthy Pregnant Women in Salinity-Affected Coastal Areas.

    Science.gov (United States)

    Scheelbeek, Pauline F D; Khan, Aneire E; Mojumder, Sontosh; Elliott, Paul; Vineis, Paolo

    2016-08-01

    Coastal areas in Southeast Asia are experiencing high sodium concentrations in drinking water sources that are commonly consumed by local populations. Salinity problems caused by episodic cyclones and subsequent seawater inundations are likely (partly) related to climate change and further exacerbated by changes in upstream river flow and local land-use activities. Dietary (food) sodium plays an important role in the global burden of hypertensive disease. It remains unknown, however, if sodium in drinking water-rather than food-has similar effects on blood pressure and disease risk. In this study, we examined the effect of drinking water sodium on blood pressure of pregnant women: increases in blood pressure in this group could severely affect maternal and fetal health. Data on blood pressure, drinking water source, and personal, lifestyle, and environmental confounders was obtained from 701 normotensive pregnant women residing in coastal Bangladesh. Generalized linear mixed regression models were used to investigate association of systolic and diastolic blood pressure of these-otherwise healthy-women with their water source. After adjustment for confounders, drinkers of tube well and pond water (high saline sources) were found to have significantly higher average systolic (+4.85 and +3.62 mm Hg) and diastolic (+2.30 and +1.72 mm Hg) blood pressures than rainwater drinkers. Drinking water salinity problems are expected to exacerbate in the future, putting millions of coastal people-including pregnant women-at increased risk of hypertension and associated diseases. There is an urgent need to further explore the health risks associated to this understudied environmental health problem and feasibility of possible adaptation strategies. © 2016 American Heart Association, Inc.

  2. On the problem of safe usage of 12MKh steel at elevated temperatures and high hydrogen pressures

    International Nuclear Information System (INIS)

    Archakov, Yu.I.; Teslya, B.M.

    1982-01-01

    The behaviour of the 12MKh steel in hydrogen at pressures of 4-100 MPa and temperatures of 450-600 deg C has been investigated to study the regularities of hydrogen corrosion process. The samples are held in hydrogen under all-round compression in autoclaves with subsequent determination of mechanical properties, carbon content and microstructure. Dependencies of time to begining of intensive embrittlement under given conditions are found. The empiric equation for the calculation of time to beginning of hydrogen corrosion is derived, the safe usage of the 12MKh steel at different temperatures and pressures are determined

  3. Inelastic Cyclic Deformation Behaviors of Type 316H Stainless Steel for Reactor Pressure Vessel of Sodium-Cooled Fast Reactor at Elevated Temperatures

    International Nuclear Information System (INIS)

    Yoon, Ji-Hyun; Hong, Seokmin; Koo, Gyeong-Hoi; Lee, Bong-Sang; Kim, Young-Chun

    2015-01-01

    Type 316H stainless steel is a primary candidate material for a reactor pressure vessel of a sodium-cooled fast (SFR) reactor which is under development in Korea. The reactor pressure vessel for a SFR is subjected to inelastic deformation induced by cyclic thermal stress. Fully reversed cyclic testing and ratcheting testing at elevated temperatures were performed to characterize the inelastic cyclic deformation behaviors of Type 316H stainless steel at the SFR operating temperature. It was found that cyclic hardening of Type 316H stainless steel was enhanced, and the accumulation of ratcheting deformation of Type 316H stainless steel was retarded at around the SFR operating temperature. The results of the tensile testing and the microstructural investigation for dislocated structures after the inelastic deformation testing showed that dynamic strain aging affected the inelastic cyclic deformation behavior of Type 316 stainless steel at around the SFR operating temperature.

  4. Properties of molecular solids and fluids at high pressures and temperatures. [Final report

    International Nuclear Information System (INIS)

    Etters, R.D.

    1985-01-01

    Equilibrium structures and orientations, lattice vibrational and librational model frequencies, intramolecular vibron mode frequencies, sound velocities, equations of state, compressibilities, and structural and orientational phase transitions in molecular solids are determined over a wide range of pressures and temperatures. In the high temperature fluid phase the equations of state, vibron frequencies, the melting transition, specific heats, compressibilities, second virial coefficients, viscosities and other transport properties, and the nature of orientational and magnetic correlations are determined. The techniques used include several strategies to optimize multi-dimensional functions as a means to determine equilibrium structures and orientations, self consistent phonon lattice dynamics methods, constant pressure and constant volume Monte-Carlo strategies with continuously deformable boundary conditions, mean field approximations, and classical perturbation methods. Systems studied include N 2 , O 2 , CO, CO 2 , F 2 , N 2 O, benzine, nitromethane, HCL, HBr, and H 2 . 50 refs., 4 figs

  5. The CHIPS Randomized Controlled Trial (Control of Hypertension in Pregnancy Study): Is Severe Hypertension Just an Elevated Blood Pressure?

    NARCIS (Netherlands)

    Magee, Laura A.; von Dadelszen, Peter; Singer, Joel; Lee, Terry; Rey, Evelyne; Ross, Susan; Asztalos, Elizabeth; Murphy, Kellie E.; Menzies, Jennifer; Sanchez, Johanna; Gafni, Amiram; Helewa, Michael; Hutton, Eileen; Koren, Gideon; Lee, Shoo K.; Logan, Alexander G.; Ganzevoort, Wessel; Welch, Ross; Thornton, Jim G.; Moutquin, Jean-Marie

    2016-01-01

    To determine whether clinical outcomes differed by occurrence of severe hypertension in the international CHIPS trial (Control of Hypertension in Pregnancy Study), adjusting for the interventions of less tight (target diastolic blood pressure [dBP] 100 mmHg) versus tight control (target dBP 85

  6. Transition between trickle flow and pulse flow in a cocurrent gas-liquid trickle-bed reactor at elevated pressures

    NARCIS (Netherlands)

    Wammes, W.J.A.; Mechielsen, S.J.; Westerterp, K.R.

    1992-01-01

    The effect of reactor pressure in the range of 0.2–2.0 MPa on the transition between the trickle-flow and the pulse-flow regime has been investigated for the non-foaming water—nitrogen and aqueous 40% ethyleneglycol—nitrogen systems. Most models and flow charts which are all based on atmospheric

  7. Study of the effects of elevated pressure and temperature on the evaporation of a single fuel droplet

    International Nuclear Information System (INIS)

    Memon, A.A.; Memon, M.A.; Durrani, H.A.

    1991-01-01

    The experimental studies were made on the evaporation of single fuel droplet in high pressure and high temperature gaseous environments. The time history of the size and the temperature of an evaporating droplet suspended on a fine quartz thread was recorded using a movie camera and an oscilloscope. The fuel used was n-heptane. The experimental range of conditions consists of gas pressure from 0 atg to 50 atg, gas temperature from 100 c to 500 c which correspond to the subcritical, critical and supercritical state of a droplet. The evaporation rate, the life time and the wet-bulb temperature of a droplet were obtained. The results showed that the temperature of an evaporating droplet increased with an increase in gas pressure and temperature, through it did not reach the critical temperature of fuel even at supercritical environments. It was evident that with an increase in gas pressure, the evaporation rate increased at high gas temperature while it decreased at low gas temperature. (author)

  8. Review of Detection and Monitoring Systems for Buried High Pressure Pipelines: Final Report

    OpenAIRE

    Asadollahi Dolatabad, Saeid; Doree, Andries G.; olde Scholtenhuis, Léon Luc; Vahdatikhaki, Faridaddin

    2017-01-01

    The Netherlands has approximately two million kilometers of underground cables and pipelines. One specific type of buried infrastructure is the distribution network of hazardous material such as gas, oil, and chemicals (‘transportleiding gevaarlijke stoffen’). This network comprises 22.000 kilometers of high-pressure transportation pipelines. Because they are located under the ground, these pipelines are subject to excavation damages. Incidents in them Belgian Gellingen (2004) and German Ludw...

  9. Collaborative Research: Atmospheric Pressure Microplasma Chemistry-Photon Synergies Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Graves, David [Univ. of California, Berkeley, CA (United States)

    2017-02-07

    Combining the effects of low temperature, atmospheric pressure microplasmas and microplasma photon sources shows greatly expanded range of applications of each of them. The plasma sources create active chemical species and these can be activated further by addition of photons and associated photochemistry. There are many ways to combine the effects of plasma chemistry and photochemistry, especially if there are multiple phases present. The project combines construction of appropriate test experimental systems, various spectroscopic diagnostics and mathematical modeling.

  10. PWR reactor pressure vessel internals license renewal industry report; revision 1. Final report

    International Nuclear Information System (INIS)

    Schwirian, R.; Robison, G.

    1994-07-01

    The U.S. nuclear power industry, through coordination by the Nuclear Management and Resources Council (NUMARC), and sponsorship by the U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI), has evaluated age-related degradation effects for a number of major plant systems, structures and components, in the license renewal technical Industry Reports (IRs). License renewal applicants may choose to reference these IRs in support of their plant-specific license renewal applications, as an equivalent to the integrated plant assessment provisions of the license renewal rule (10 CFR Part 54). Pressurized water reactor (PWR) reactor pressure vessel (RPV) internals designed by all three U.S. PWR nuclear steam supply system vendors have been evaluated relative to the effects of age-related degradation mechanisms; the capability of current design limits; inservice examination, testing, repair, refurbishment, and other programs to manage these effects; and the assurance that these internals can continue to perform their intended safety functions in the license renewal term. This industry report (IR), one of a series of ten, provides a generic technical basis for evaluation of PWR reactor pressure vessel internals for license renewal

  11. Simulation Tool for Dielectric Barrier Discharge Plasma Actuators at Atmospheric and Sub-Atmospheric Pressures: SBIR Phase I Final Report

    Science.gov (United States)

    Likhanskii, Alexandre

    2012-01-01

    This report is the final report of a SBIR Phase I project. It is identical to the final report submitted, after some proprietary information of administrative nature has been removed. The development of a numerical simulation tool for dielectric barrier discharge (DBD) plasma actuator is reported. The objectives of the project were to analyze and predict DBD operation at wide range of ambient gas pressures. It overcomes the limitations of traditional DBD codes which are limited to low-speed applications and have weak prediction capabilities. The software tool allows DBD actuator analysis and prediction for subsonic to hypersonic flow regime. The simulation tool is based on the VORPAL code developed by Tech-X Corporation. VORPAL's capability of modeling DBD plasma actuator at low pressures (0.1 to 10 torr) using kinetic plasma modeling approach, and at moderate to atmospheric pressures (1 to 10 atm) using hydrodynamic plasma modeling approach, were demonstrated. In addition, results of experiments with pulsed+bias DBD configuration that were performed for validation purposes are reported.

  12. The tunnel sealing experiment: The construction and performance of full scale clay and concrete bulkheads at elevated pressure and temperature

    International Nuclear Information System (INIS)

    Martino, J.B.; Dixon, D.A.; Vignal, B.; Fujita, T.

    2006-01-01

    Concepts for deep geologic disposal of radioactive waste, as proposed by many international organizations, include bulkheads or plugs in the shaft, or at the entrances to disposal rooms, or both. The seals are primarily to prevent groundwater transport of radioisotopes along underground openings but also provide a measure of security by restricting tunnel access. The safety of the respective disposal systems relies on the combined performance of the natural barriers (host rock) and engineered barriers (the waste form, the waste container, the buffer barrier, the room, tunnel and shaft backfill and sealing materials). To understand the functionality of these systems it is important to study them in whole or in part at full scale. One such study was the Tunnel Sealing Experiment (TSX), a full-scale tunnel seal component study. The TSX showed it is possible to construct tunnel seals that limit axial flow under high hydraulic gradient and elevated temperature. The clay and concrete bulkheads had seepage rates of 1 mL/min and 10 mL/min at ambient temperature. Elevated temperatures caused a further decrease in seepage past the concrete bulkhead to approximately 2-3 mL/min. (author)

  13. Investigation of one-dimensional interfacial area transport for vertical upward air–water two-phase flow in an annular channel at elevated pressures

    International Nuclear Information System (INIS)

    Ozar, B.; Brooks, C.S.; Euh, D.J.; Hibiki, T.; Ishii, M.

    2013-01-01

    Highlights: • Interfacial area transport equation (IATE) for a rectangular duct is modified for an annulus. • IATE predicts interfacial area transport in bubbly-to-churn flow. • Scalability of IATE to elevated pressure conditions is validated. • Detailed 1D interfacial area transport data are presented. • Detailed interfacial area transport mechanisms are discussed. -- Abstract: The interfacial area transport of vertical, upward, air–water two-phase flows in an annular channel has been investigated at different system pressures. The inner and outer diameters of the annular channel were 19.1 mm and 38.1 mm, respectively. Twenty three inlet flow conditions were selected, which covered bubbly, cap-bubbly, and churn-turbulent flows. These flow conditions also overlapped with twelve conditions of a previous study for comparison. The local flow parameters, such as void fractions, interfacial area concentrations (IAC), and bubble interface velocities, were measured at nine radial positions for the three axial locations and converted into area-averaged parameters. The axial evolutions of local flow structure were interpreted in terms of bubble coalescence, breakup, expansion of the gas-phase due to pressure drop and system pressure. An assessment of interfacial area transport equation (IATE) was made and compared with the experimental data. A discussion of the comparison between model prediction and the experimental results were made

  14. Investigation of one-dimensional interfacial area transport for vertical upward air–water two-phase flow in an annular channel at elevated pressures

    Energy Technology Data Exchange (ETDEWEB)

    Ozar, B., E-mail: ozar@fauske.com [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907-2017 (United States); Brooks, C.S. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907-2017 (United States); Euh, D.J. [Korea Atomic Energy Research Institute, 150 Deokjin, Yuseong, Daejeon 305-353 (Korea, Republic of); Hibiki, T.; Ishii, M. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907-2017 (United States)

    2013-10-15

    Highlights: • Interfacial area transport equation (IATE) for a rectangular duct is modified for an annulus. • IATE predicts interfacial area transport in bubbly-to-churn flow. • Scalability of IATE to elevated pressure conditions is validated. • Detailed 1D interfacial area transport data are presented. • Detailed interfacial area transport mechanisms are discussed. -- Abstract: The interfacial area transport of vertical, upward, air–water two-phase flows in an annular channel has been investigated at different system pressures. The inner and outer diameters of the annular channel were 19.1 mm and 38.1 mm, respectively. Twenty three inlet flow conditions were selected, which covered bubbly, cap-bubbly, and churn-turbulent flows. These flow conditions also overlapped with twelve conditions of a previous study for comparison. The local flow parameters, such as void fractions, interfacial area concentrations (IAC), and bubble interface velocities, were measured at nine radial positions for the three axial locations and converted into area-averaged parameters. The axial evolutions of local flow structure were interpreted in terms of bubble coalescence, breakup, expansion of the gas-phase due to pressure drop and system pressure. An assessment of interfacial area transport equation (IATE) was made and compared with the experimental data. A discussion of the comparison between model prediction and the experimental results were made.

  15. Dietary Sodium and Potassium Intake is Not Associated with Elevated Blood Pressure in US Adults with No Prior History of Hypertension

    Science.gov (United States)

    Sharma, Shailendra; McFann, Kim; Chonchol, Michel; Kendrick, Jessica

    2014-01-01

    The relationship between dietary sodium and potassium intake with elevated blood pressure (BP) levels is unclear. We examined the association between dietary sodium and potassium intake and BP levels in 6985 adults 18 years of age or older with no prior history of hypertension who participated in the National Health and Nutrition Examination Survey (2001–2006). After adjustment for age, sex, race, body mass index, diabetes and eGFR, there was no association between higher quartiles of sodium or potassium intake with the risk of a BP >140/90 mmHg or >130/80 mmHg. There was also no relationship between dietary sodium and potassium intake with BP when systolic and diastolic BP were measured as continuous outcomes (p=0.68 and p=0.74, respectively). Furthermore, no association was found between combinations of sodium and potassium intake with elevated BP. In the US adult population without hypertension, increased dietary sodium or low potassium intake was not associated with elevated BP levels. PMID:24720647

  16. Comparisons of the Effects of Elevated Vapor Pressure Deficit on Gene Expression in Leaves among Two Fast-Wilting and a Slow-Wilting Soybean.

    Directory of Open Access Journals (Sweden)

    Mura Jyostna Devi

    Full Text Available Limiting the transpiration rate (TR of a plant under high vapor pressure deficit (VPD has the potential to improve crop yield under drought conditions. The effects of elevated VPD on the expression of genes in the leaves of three soybean accessions, Plant Introduction (PI 416937, PI 471938 and Hutcheson (PI 518664 were investigated because these accessions have contrasting responses to VPD changes. Hutcheson, a fast-wilting soybean, and PI 471938, a slow-wilting soybean, respond to increased VPD with a linear increase in TR. TR of the slow-wilting PI 416937 is limited when VPD increases to greater than about 2 kPa. The objective of this study was to identify the response of the transcriptome of these accessions to elevated VPD under well-watered conditions and identify responses that are unique to the slow-wilting accessions. Gene expression analysis in leaves of genotypes PI 471938 and Hutcheson showed that 22 and 1 genes, respectively, were differentially expressed under high VPD. In contrast, there were 944 genes differentially expressed in PI 416937 with the same increase in VPD. The increased alteration of the transcriptome of PI 416937 in response to elevated VPD clearly distinguished it from the other slow-wilting PI 471938 and the fast-wilting Hutcheson. The inventory and analysis of differentially expressed genes in PI 416937 in response to VPD is a foundation for further investigation to extend the current understanding of plant hydraulic conductivity in drought environments.

  17. Method of making Tl-Sr-Ca-Cu-oxide superconductors comprising heating at elevated pressures in a sealed container

    International Nuclear Information System (INIS)

    Lechtev, W.L.; Osofsky, M.S.; Skelton, E.F.; Toth, L.E.

    1992-01-01

    This patent describes a method of forming a Tl-Sr-Ca-Cu-oxide high T c superconductor. It comprises forming a reaction mixture of the oxides of Sr, Cu, Ca, and Tl in stoichiometric proportions to make a Tl-Sr-Ca-Cu-oxide high T c superconducting compound; compressing the reaction mixture into a hard body; placing the hard body into a container for containing thallium vapor; evacuating and sealing the hard body in the container; heating the hard body and the container at a temperature of about 800 degrees C to about 950 degrees C and under pressure of at least about 30,000 psi until the container metal around the hard body and the oxides of Tl, Sr, Ca, and Cu react to form a superconducting compound; and cooling the superconducting compound to room temperature and returning the superconducting compound to atmospheric pressure

  18. Stress corrosion cracking studies of reactor pressure vessel steels. Final report

    International Nuclear Information System (INIS)

    Van Der Sluys, W.A.

    1996-10-01

    The objective of this project was to perform a critical review of the information available in open literature on stress corrosion cracking of reactor pressure vessel materials in simulated light-water-reactor (LWR) conditions, develop a test procedure for conducting stress corrosion crack growth experiments in simulated LWR environments, and conduct a test program in an effort to duplicate some of the data available from the literature. The authors concluded that stress corrosion crack growth has been observed in pressure vessel steels under laboratory test conditions. The composition of the water in most cases where growth was observed is outside of the composition specified for operating conditions. Crack growth was observed in the experiments performed in this program, and it was intermittent. The cracking would start and stop for no apparent reason. In most instances, it would not restart without the change of some external variable. In a few instances, it restarted on its own. Crack growth rates as high as 3.6 x 10 -9 m/sec were observed in pressure vessel steels in high-purity water with 8 ppm oxygen. These high crack growth rates were observed for extremely short bursts in crack extension. They could not be sustained for crack growth extensions greater than a few tenths of a millimeter. From the results of this project it appears highly unlikely that stress corrosion cracking will be observed in operating nuclear plants where the coolant composition is maintained within water chemistry guidelines. However, more work is needed to better define the contaminations that cause crack growth. The crack growth rates are so high and the threshold values for crack nucleation are so low that the conditions causing them need to be well defined and avoided

  19. Numerical Modelling of Soot Formation in Laminar Axisymmetric Ethylene-Air Coflow Flames at Atmospheric and Elevated Pressures

    KAUST Repository

    Rakha, Ihsan Allah

    2015-05-01

    The steady coflow diffusion flame is a widely used configuration for studying combustion kinetics, flame dynamics, and pollutant formation. In the current work, a set of diluted ethylene-air coflow flames are simulated to study the formation, growth, and oxidation of soot, with a focus on the effects of pressure on soot yield. Firstly, we assess the ability of a high performance CFD solver, coupled with detailed transport and kinetic models, to reproduce experimental measurements, like the temperature field, the species’ concentrations and the soot volume fraction. Fully coupled conservation equations for mass, momentum, energy, and species mass fractions are solved using a low Mach number formulation. Detailed finite rate chemistry describing the formation of Polycyclic Aromatic Hydrocarbons up to cyclopenta[cd]pyrene is used. Soot is modeled using a moment method and the resulting moment transport equations are solved with a Lagrangian numerical scheme. Numerical and experimental results are compared for various pressures. Reasonable agreement is observed for the flame height, temperature, and the concentrations of various species. In each case, the peak soot volume fraction is predicted along the centerline as observed in the experiments. The predicted integrated soot mass at pressures ranging from 4-8 atm, scales as P2.1, in satisfactory agreement with the measured integrated soot pressure scaling (P2.27). Significant differences in the mole fractions of benzene and PAHs, and the predicted soot volume fractions are found, using two well-validated chemical kinetic mechanisms. At 4 atm, one mechanism over-predicts the peak soot volume fraction by a factor of 5, while the other under-predicts it by a factor of 5. A detailed analysis shows that the fuel tube wall temperature has an effect on flame stabilization.

  20. Experimental study of centrifugal pump performance under steam-water two-phase flow conditions at elevated pressures

    International Nuclear Information System (INIS)

    Chan, A.M.C.; Barreca, S.L.; Hartlen, R.T.

    1991-01-01

    The performance of a centrifugal pump under two-phase flow conditions was studied in a closed loop. System voids of increasing magnitude were attained by draining water from the loop in steps. The operating temperature/pressure were varied from 110 degrees C/0.15 MPa to 260 degrees C/4.7 MPa. Only tests in the first quadrant were conducted. In this paper the head-flow characteristics and pump head degradation data are presented and discussed

  1. Interfacial area transport of vertical upward air-water two-phase flow in an annulus at elevated pressures

    International Nuclear Information System (INIS)

    Ozar, Basar; Hibiki, Takashi; Ishii, Mamoru; Euh, Dong-Jin

    2009-01-01

    The interfacial area transport of vertical, upward, air-water two-phase flows in an annular channel has been investigated at different system pressures. The inner and outer diameters of the annular channel were 19.1 mm and 38.1 mm, respectively. Twenty three inlet flow conditions were selected, which coverED bubbly, cap-slug, and churn-turbulent flows. These flow conditions also overlapped with twelve conditions of our previous study for comparison. The local flow parameters, such as void fractions, interfacial area concentrations (IAC), and bubble interface velocities, were measured at nine radial positions for the three axial locations (z/D h =52, 149 and 230) and converted into area-averaged parameters. The axial evolutions of local flow structure was interpreted in terms of bubble coalescence, breakup, expansion of the gas-phase due to pressure drop and system pressure. An assessment of interfacial area transport equation (IATE) was made and compared with the experimental data. A discussion of the comparison between model prediction and the experimental results were made. (author)

  2. Salt-induced epithelial-to-mesenchymal transition in Dahl salt-sensitive rats is dependent on elevated blood pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Mu, J.J.; Liu, F.Q.; Ren, K.Y.; Xiao, H.Y. [Xi' an Jiaotong University, Medical College, First Affiliated Hospital, Cardiovascular Department, Xi' an, China, Cardiovascular Department, First Affiliated Hospital, Medical College, Xi' an Jiaotong University, Xi' an (China); Ministry of Education, Key Laboratory of Environment and Genes Related to Diseases, Xi' an, China, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi' an (China); Yang, Z. [Xi' an Jiaotong University, Medical College, First Affiliated Hospital, Department of Pathology, Xi' an, China, Department of Pathology, First Affiliated Hospital, Medical College, Xi' an Jiaotong University, Xi' an (China); Yuan, Z.Y. [Xi' an Jiaotong University, Medical College, First Affiliated Hospital, Cardiovascular Department, Xi' an, China, Cardiovascular Department, First Affiliated Hospital, Medical College, Xi' an Jiaotong University, Xi' an (China); Ministry of Education, Key Laboratory of Environment and Genes Related to Diseases, Xi' an, China, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi' an (China)

    2014-03-03

    Dietary salt intake has been linked to hypertension and cardiovascular disease. Accumulating evidence has indicated that salt-sensitive individuals on high salt intake are more likely to develop renal fibrosis. Epithelial-to-mesenchymal transition (EMT) participates in the development and progression of renal fibrosis in humans and animals. The objective of this study was to investigate the impact of a high-salt diet on EMT in Dahl salt-sensitive (SS) rats. Twenty-four male SS and consomic SS-13{sup BN} rats were randomized to a normal diet or a high-salt diet. After 4 weeks, systolic blood pressure (SBP) and albuminuria were analyzed, and renal fibrosis was histopathologically evaluated. Tubular EMT was evaluated using immunohistochemistry and real-time PCR with E-cadherin and alpha smooth muscle actin (α-SMA). After 4 weeks, SBP and albuminuria were significantly increased in the SS high-salt group compared with the normal diet group. Dietary salt intake induced renal fibrosis and tubular EMT as identified by reduced expression of E-cadherin and enhanced expression of α-SMA in SS rats. Both blood pressure and renal interstitial fibrosis were negatively correlated with E-cadherin but positively correlated with α-SMA. Salt intake induced tubular EMT and renal injury in SS rats, and this relationship might depend on the increase in blood pressure.

  3. Salt-induced epithelial-to-mesenchymal transition in Dahl salt-sensitive rats is dependent on elevated blood pressure

    International Nuclear Information System (INIS)

    Wang, Y.; Mu, J.J.; Liu, F.Q.; Ren, K.Y.; Xiao, H.Y.; Yang, Z.; Yuan, Z.Y.

    2014-01-01

    Dietary salt intake has been linked to hypertension and cardiovascular disease. Accumulating evidence has indicated that salt-sensitive individuals on high salt intake are more likely to develop renal fibrosis. Epithelial-to-mesenchymal transition (EMT) participates in the development and progression of renal fibrosis in humans and animals. The objective of this study was to investigate the impact of a high-salt diet on EMT in Dahl salt-sensitive (SS) rats. Twenty-four male SS and consomic SS-13 BN rats were randomized to a normal diet or a high-salt diet. After 4 weeks, systolic blood pressure (SBP) and albuminuria were analyzed, and renal fibrosis was histopathologically evaluated. Tubular EMT was evaluated using immunohistochemistry and real-time PCR with E-cadherin and alpha smooth muscle actin (α-SMA). After 4 weeks, SBP and albuminuria were significantly increased in the SS high-salt group compared with the normal diet group. Dietary salt intake induced renal fibrosis and tubular EMT as identified by reduced expression of E-cadherin and enhanced expression of α-SMA in SS rats. Both blood pressure and renal interstitial fibrosis were negatively correlated with E-cadherin but positively correlated with α-SMA. Salt intake induced tubular EMT and renal injury in SS rats, and this relationship might depend on the increase in blood pressure

  4. Pretreatment of flaxseed protein isolate by high hydrostatic pressure: Impacts on protein structure, enzymatic hydrolysis and final hydrolysate antioxidant capacities.

    Science.gov (United States)

    Perreault, Véronique; Hénaux, Loïc; Bazinet, Laurent; Doyen, Alain

    2017-04-15

    The effect of high hydrostatic pressure (HHP) on flaxseed protein structure and peptide profiles, obtained after protein hydrolysis, was investigated. Isolated flaxseed protein (1%, m/v) was subjected to HHP (600MPa, 5min or 20min at 20°C) prior to hydrolysis with trypsin only and trypsin-pronase. The results demonstrated that HHP treatment induced dissociation of flaxseed proteins and generated higher molecular weight aggregates as a function of processing duration. Fluorescence spectroscopy showed that HHP treatment, as well as processing duration, had an impact on flaxseed protein structure since exposition of hydrophobic amino acid tyrosine was modified. Except for some specific peptides, the concentrations of which were modified, similar peptide profiles were obtained after hydrolysis of pressure-treated proteins using trypsin. Finally, hydrolysates obtained using trypsin-pronase had a greater antioxidant capacity (ORAC) than control samples; these results confirmed that HHP enhanced the generation of antioxidant peptides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Measuring in-vivo and in-situ ex-vivo the 3D deformation of the lamina cribrosa microstructure under elevated intraocular pressure

    Science.gov (United States)

    Wei, Junchao; Yang, Bin; Voorhees, Andrew P.; Tran, Huong; Brazile, Bryn; Wang, Bo; Schuman, Joel; Smith, Matthew A.; Wollstein, Gadi; Sigal, Ian A.

    2018-02-01

    Elevated intraocular pressure (IOP) deforms the lamina cribrosa (LC), a structure within the optic nerve head (ONH) in the back of the eye. Evidence suggests that these deformations trigger events that eventually cause irreversible blindness, and have therefore been studied in-vivo using optical coherence tomography (OCT), and ex-vivo using OCT and a diversity of techniques. To the best of our knowledge, there have been no in-situ ex-vivo studies of LC mechanics. Our goal was two-fold: to introduce a technique for measuring 3D LC deformations from OCT, and to determine whether deformations of the LC induced by elevated IOP differ between in-vivo and in-situ ex-vivo conditions. A healthy adult rhesus macaque monkey was anesthetized and IOP was controlled by inserting a 27- gauge needle into the anterior chamber of the eye. Spectral domain OCT was used to obtain volumetric scans of the ONH at normal and elevated IOPs. To improve the visibility of the LC microstructure the scans were first processed using a novel denoising technique. Zero-normalized cross-correlation was used to find paired corresponding locations between images. For each location pair, the components of the 3D strain tensor were determined using non-rigid image registration. A mild IOP elevation from 10 to 15mmHg caused LC effective strains as large as 3%, and about 50% larger in-vivo than in-situ ex-vivo. The deformations were highly heterogeneous, with substantial 3D components, suggesting that accurate measurement of LC microstructure deformation requires high-resolution volumes. This technique will help improve understanding of LC biomechanics and how IOP contributes to glaucoma.

  6. Muscle Weakness Is Associated With an Increase of Left Ventricular Mass Through Excessive Blood Pressure Elevation During Exercise in Patients With Hypertension.

    Science.gov (United States)

    Kamada, Yumi; Masuda, Takashi; Tanaka, Shinya; Akiyama, Ayako; Nakamura, Takeshi; Hamazaki, Nobuaki; Okubo, Michihito; Kobayashi, Naoyuki; Ako, Junya

    2017-08-03

    Autonomic imbalance in hypertension induces excessive blood pressure (BP) elevation during exercise, thereby increasing left ventricular mass (LVM). Although muscle weakness enhances autonomic imbalance by stimulating muscle sympathetic activity during exercise, it is unclear whether muscle weakness is associated with an increase of LVM in patients with hypertension. This study aimed to investigate the relationships between muscle weakness, BP elevation during exercise, and LVM in these patients. Eighty-six hypertensive patients aged 69 ± 8 years with controlled resting BP (ie, exercise test performed at moderate intensity (ΔNORA and ΔPWV, respectively). A difference between baseline and peak systolic BP during the exercise test was defined as BP elevation during exercise (ΔSBP). Relationships between muscle strength, ΔNORA, ΔPWV, ΔSBP, BNP, and LVMI were analyzed, and significant factors increasing LVM were identified using univariate and multivariate regression analyses. Muscle strength was negatively correlated with ΔNORA (r = -0.202, P = 0.048), ΔPWV (r = -0.328, P = 0.002), ΔSBP (r = -0.230, P = 0.033), BNP (r = -0.265, P = 0.014), and LVMI (r = -0.233, P = 0.031). LVMI was positively correlated with ΔPWV (r = 0.246, P = 0.023) and ΔSBP (r = 0.307, P = 0.004). Muscle strength was a significant independent factor associated with LVMI (β = -0.331, P = 0.010). Our findings suggest that muscle weakness is associated with an increase of LVM through excessive BP elevation during exercise in patients with hypertension.

  7. Discriminatory ability of right atrial volumes with two- and three-dimensional echocardiography to detect elevated right atrial pressure in pulmonary hypertension.

    Science.gov (United States)

    Ostenfeld, Ellen; Werther-Evaldsson, Anna; Engblom, Henrik; Ingvarsson, Annika; Roijer, Anders; Meurling, Carl; Holm, Johan; Rådegran, Göran; Carlsson, Marcus

    2018-03-01

    Pulmonary hypertension (PH) patients have high mortality due to right ventricular failure. Predictors of poor prognostic outcome are increased right atrial volume (RAV) and elevated mean right atrial pressure (mRAP). Our aim was to determine whether RAV measured with 2D echocardiography (2DE) and 3D echocardiography (3DE) can detect elevated mRAP in patients evaluated for PH. Of 85 patients prospectively evaluated for PH, 44 patients (63 ± 15 years, 57% female) had 2DE, 3DE and right heart catheterization within 48 h and were in sinus rhythm. Maximum (RAV max ) and minimum (RAV min ) volumes were measured with 3DE. 2D maximum RAV and RA area, inferior vena cava diameter and collapsibility were measured. Invasive mRAP > 8 mmHg was predefined as elevated. RAV max and RAV min correlated with mRAP (r = 0·40 and r = 0·35, P8 mmHg. The optimal threshold was 57 ml m -2 for RAV max , 31 ml m -2 for RAV min and 36 ml m -2 for 2DE RAV. Enlarged RA measures with 2DE and 3DE have better discriminatory ability compared with IVC measures, to detect elevated mRAP in patients evaluated for PH. © 2016 The Authors. Clinical Physiology and Functional Imaging published by John Wiley & Sons Ltd on behalf of Scandinavian Society of Clinical Physiology and Nuclear Medicine.

  8. Accuracy of Blood Pressure-to-Height Ratio to Define Elevated Blood Pressure in Children and Adolescents: The CASPIAN-IV Study.

    Science.gov (United States)

    Kelishadi, Roya; Bahreynian, Maryam; Heshmat, Ramin; Motlagh, Mohammad Esmail; Djalalinia, Shirin; Naji, Fatemeh; Ardalan, Gelayol; Asayesh, Hamid; Qorbani, Mostafa

    2016-02-01

    The aim of this study was to propose a simple practical diagnostic criterion for pre-hypertension (pre-HTN) and hypertension (HTN) in the pediatric age group. This study was conducted on a nationally representative sample of 14,880 students, aged 6-18 years. HTN and pre-HTN were defined as systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) ≥ 95 and 90-95th percentile for age, gender, and height, respectively. By using the area under the curve (AUC) of the receiver operator characteristic curves, we estimated the diagnostic accuracy of two indexes of SBP-to-height ratio (SBPHR) and DBP-to-height (DBPHR) to define pre-HTN and HTN. Overall, SBPHR performed relatively well in classifying subjects to HTN (AUC 0.80-0.85) and pre-HTN (AUC 0.84-0.90). Likewise, DBPHR performed relatively well in classifying subjects to HTN (AUC 0.90-0.97) and pre-HTN (AUC 0.70-0.83). Two indexes of SBPHR and DBPHR are considered as valid, simple, inexpensive, and accurate tools to diagnose pre-HTN and HTN in pediatric age group.

  9. High-fat diet amplifies renal renin angiotensin system expression, blood pressure elevation, and renal dysfunction caused by Ceacam1 null deletion.

    Science.gov (United States)

    Li, Caixia; Culver, Silas A; Quadri, Syed; Ledford, Kelly L; Al-Share, Qusai Y; Ghadieh, Hilda E; Najjar, Sonia M; Siragy, Helmy M

    2015-11-01

    Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAMl), a substrate of the insulin receptor tyrosine kinase, regulates insulin action by promoting insulin clearance. Global null mutation of Ceacam1 gene (Cc1(-/-)) results in features of the metabolic syndrome, including insulin resistance, hyperinsulinemia, visceral adiposity, elevated blood pressure, and albuminuria. It also causes activation of the renal renin-angiotensin system (RAS). In the current study, we tested the hypothesis that high-fat diet enhances the expression of RAS components. Three-month-old wild-type (Cc1(+/+)) and Cc1(-/-) mice were fed either a regular or a high-fat diet for 8 wk. At baseline under regular feeding conditions, Cc1(-/-) mice exhibited higher blood pressure, urine albumin-to-creatinine ratio (UACR), and renal expression of angiotensinogen, renin/prorenin, angiotensin-converting enzyme, (pro)renin receptor, angiotensin subtype AT1 receptor, angiotensin II, and elevated PI3K phosphorylation, as detected by p85α (Tyr(508)) immunostaining, inflammatory response, and the expression of collagen I and collagen III. In Cc1(+/+) mice, high-fat diet increased blood pressure, UACR, the expression of angiotensin-converting enzyme and angiotensin II, PI3K phosphorylation, inflammatory response, and the expression of collagen I and collagen III. In Cc1(-/-) mice, high-fat intake further amplified these parameters. Immunohistochemical staining showed increased p-PI3K p85α (Tyr(508)) expression in renal glomeruli, proximal, distal, and collecting tubules of Cc1(-/-) mice fed a high-fat diet. Together, this demonstrates that high-fat diet amplifies the permissive effect of Ceacam1 deletion on renal expression of all RAS components, PI3K phosphorylation, inflammation, and fibrosis. Copyright © 2015 the American Physiological Society.

  10. Low-pressure approach to the formation and study of exciplex systems. Final report

    International Nuclear Information System (INIS)

    Sanzone, G.

    1981-06-01

    Under this contract, the following goals were set. (1) Development and construction of an experimental system for the study of the kinetics of excimers, and demonstrate the validity of the low-pressure approach to such studies. The apparatus was to consist of the following: (a) cluster-molecular-beam source of van der Waals dimers and higher oligomers; (b) modulated-beam mass spectrometer; (c) low-energy electron beam for the production of excimers; (d) vacuum-ultraviolet to Visible detection and photon-counting system to monitor excimer emission; (e) flash-excited tunable laser for studies of resonant self-absorptions. (2) Form Ar 2 in its van der Waals ground state. (3) Produce Ar 2 * by electron bombardment of Ar 2 . (4) Perform fluorescence and photon absorption studies of Ar 2 *. At the end of the contract period, goals 1 and 2 have been met; experiments 3 and 4 have been designed

  11. In situ NMR studies of hydrogen storage kinetics and molecular diffusion in clathrate hydrate at elevated hydrogen pressures

    Energy Technology Data Exchange (ETDEWEB)

    Okuchi, T. [Okayama Univ., Misasa, Tottori (Japan); Moudrakovski, I.L.; Ripmeester, J.A. [National Research Council of Canada, Ottawa, ON (Canada). Steacie Inst. for Molecular Sciences

    2008-07-01

    The challenge of storing high-density hydrogen into compact host media was investigated. The conventional storage scheme where an aqueous solution is frozen with hydrogen gas is too slow for practical use in a hydrogen-based society. Therefore, the authors developed a faster method whereby hydrogen was stored into gas hydrates. The hydrogen gas was directly charged into hydrogen-free, crystalline hydrate powders with partly empty lattices. The storage kinetics and hydrogen diffusion into the hydrate was observed in situ by nuclear magnetic resonance (NMR) in a pressurized tube cell. At pressures up to 20 MPa, the storage was complete within 80 minutes, as observed by growth of stored-hydrogen peak into the hydrate. Hydrogen diffusion within the crystalline hydrate media is the rate-determining step of current storage scheme. Therefore, the authors measured the diffusion coefficient of hydrogen molecules using the pulsed field gradient NMR method. The results show that the stored hydrogen is very mobile at temperatures down to 250 K. As such, the powdered hydrate media should work well even in cold environments. Compared with more prevailing hydrogen storage media such as metal hydrides, clathrate hydrates have the advantage of being free from hydrogen embrittlement, more chemically durable, more environmentally sound, and economically affordable. It was concluded that the powdered clathrate hydrate is suitable as a hydrogen storage media. 22 refs., 4 figs.

  12. Removal of dust from flue gas at elevated temperatures and pressures. Roeggasrensning for stoev ved hoej temperatur og hoejt tryk

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, D. V.; Rasmussen, J.

    1989-06-15

    Several new coal-based power generation systems are now ready for commercial application. Especially Integrated coal Gasification with combined Cycle (IGCC) and pressurized Fluidized Bed Combustion possess the potential for reducing emissions of SOx, NOx and particulates compared to conventional technology. In addition to this a decrease in heat-rate is possible. However, the decrease in heat-rate is dependant on the temperature of which the removal of particulated and gaseous pollutants takes place. Using state-of-the-art technology this temperature is 25-40 deg. C, but the efficiency improvement will only be substantial if the temperature can be raised to 400-500 deg. C or more. The coal gasification, which is the heart of an IGCC-system, can be caried out in a number of ways. Since the hot gas clean-up equipment (HGCU) to some extent is dependant on the gasification technology used, a description of the leading coal gasification systems is given. It is concluded that special interest should be given to gasifiers of the entrained flow type. The aim is to develope a HGCU-system for the removal of gaseous pollutants as well as particulate matter. The operating principles and stage of development of the competing technologies for dust removal at high temperature and pressure are described. Special attention is paid to the electrostatic precipitator, and possible solutions to problems related ot this technology are given. (AB) 165 refs.

  13. Phase stability and elastic properties of Tan+1AlCn (n = 1-3) at high pressure and elevated temperature

    International Nuclear Information System (INIS)

    Music, Denis; Emmerlich, Jens; Schneider, Jochen M

    2007-01-01

    We have studied the electronic structure of Ta n+1 AlC n (space group P6 3 /mmc,n = 1-3) under uniform compression from 0 to 60 GPa and at temperatures from 0 to 1500 K using ab initio calculations. These phases can be characterized by alternating layers of high and low electron density and are referred to as nanolaminates. At 0 K we observe similar compressibilities in both the a and c directions for all phases investigated. This is unusual for nanolaminates. Based on the density of states analysis, we propose that these similar compressibilities may be caused by an increase in Ta-Al and Ta-Ta bonding strength as well as a stronger long-range interaction between TaC-TaC layers. No evidence of a phase transition is observed as the pressure is increased to 60 GPa. However, as the temperature is increased to approximately 1000 K without applying pressure, a first-order phase transition occurs in Ta 3 AlC 2 . These results are relevant for applications of Ta n+1 AlC n at elevated temperature and pressure

  14. Severely Elevated Blood Pressure and Early Mortality in Children with Traumatic Brain Injuries: The Neglected End of the Spectrum.

    Science.gov (United States)

    Johnson, M Austin; Borgman, Matthew A; Cannon, Jeremy W; Kuppermann, Nathan; Neff, Lucas P

    2018-05-01

    In adults with traumatic brain injuries (TBI), hypotension and hypertension at presentation are associated with mortality. The effect of age-adjusted blood pressure in children with TBI has been insufficiently studied. We sought to determine if age-adjusted hypertension in children with severe TBI is associated with mortality. This was a retrospective analysis of the Department of Defense Trauma Registry (DoDTR) between 2001 and 2013. We included for analysis patients children >10 years or children ≤10 years. We performed multivariable logistic regression and Cox regression to determine if BP categories were associated with mortality. Of 4,990 children included in the DoDTR, 740 met criteria for analysis. Fifty patients (6.8%) were hypotensive upon arrival to the ED, 385 (52.0%) were normotensive, 115 (15.5%) had moderate hypertension, and 190 (25.7%) had severe hypertension. When compared to normotensive patients, moderate and severe hypertension patients had similar Injury Severity Scores, similar AIS head scores, and similar frequencies of neurosurgical procedures. Multivariable logistic regression demonstrated that hypotension (odd ratio [OR] 2.85, 95 confidence interval [CI] 1.26-6.47) and severe hypertension (OR 2.58, 95 CI 1.32-5.03) were associated with increased 24-hour mortality. Neither hypotension (Hazard ratio (HR) 1.52, 95 CI 0.74-3.11) nor severe hypertension (HR 1.65, 95 CI 0.65-2.30) was associated with time to mortality. Pediatric age-adjusted hypertension is frequent after severe TBI. Severe hypertension is strongly associated with 24-hour mortality. Pediatric age-adjusted blood pressure needs to be further evaluated as a critical marker of early mortality.

  15. Severely Elevated Blood Pressure and Early Mortality in Children with Traumatic Brain Injuries: The Neglected End of the Spectrum

    Directory of Open Access Journals (Sweden)

    Matthew A. Borgman

    2018-04-01

    Full Text Available Introduction: In adults with traumatic brain injuries (TBI, hypotension and hypertension at presentation are associated with mortality. The effect of age-adjusted blood pressure in children with TBI has been insufficiently studied. We sought to determine if age-adjusted hypertension in children with severe TBI is associated with mortality. Methods: This was a retrospective analysis of the Department of Defense Trauma Registry (DoDTR between 2001 and 2013. We included for analysis patients 10 years or < 70mmHg + (2 × age for children ≤10 years. We performed multivariable logistic regression and Cox regression to determine if BP categories were associated with mortality. Results: Of 4,990 children included in the DoDTR, 740 met criteria for analysis. Fifty patients (6.8% were hypotensive upon arrival to the ED, 385 (52.0% were normotensive, 115 (15.5% had moderate hypertension, and 190 (25.7% had severe hypertension. When compared to normotensive patients, moderate and severe hypertension patients had similar Injury Severity Scores, similar AIS head scores, and similar frequencies of neurosurgical procedures. Multivariable logistic regression demonstrated that hypotension (odd ratio [OR] 2.85, 95 confidence interval [CI] 1.26–6.47 and severe hypertension (OR 2.58, 95 CI 1.32–5.03 were associated with increased 24-hour mortality. Neither hypotension (Hazard ratio (HR 1.52, 95 CI 0.74–3.11 nor severe hypertension (HR 1.65, 95 CI 0.65–2.30 was associated with time to mortality. Conclusion: Pediatric age-adjusted hypertension is frequent after severe TBI. Severe hypertension is strongly associated with 24-hour mortality. Pediatric age-adjusted blood pressure needs to be further evaluated as a critical marker of early mortality.

  16. Evaluation of neutron irradiation embrittlement in the Korean reactor pressure vessel steels (Final Report)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, J. H.; Lee, B. S.; Chi, S. H.; Kim, J. H.; Oh, Y. J.; Yoon, J. H.; Kwon, S. C.; Park, D. G.; Kang, Y. H.; Choo, K. N.; Oh, J. M.; Park, S. J.; Kim, B. K.; Shin, Y. T.; Cho, M. S.; Sohn, J. M.; Kim, D. S.; Choo, Y. S.; Ahn, S. B.; Oh, W. H. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-05-01

    Reactor pressure vessel materials, which were produced by a domestic company, Doosan Heavy Industries and construction Co., Ltd., have been evaluated using the neutron irradiation facility HANARO. For this evaluation, instrumented capsules were used for neutron irradiation of various kinds of specimens made of different heats of steels, which are VCD(Y4), VCD+Al(U4), Si+Al(Y5), U4 weld metal, and U4 HAZ, respectively. The fast neutron fluence levels ranged 1 to 5 (x10{sup 19} n/cm{sup 2}, E>1MeV) depending on the specimens and the irradiation temperature was controlled within 290{+-}10 deg C. The test results showed that, in the ranking of the material properties of the base metals, both before and after neutron irradiation, Y5 is the best, U4 the next and Y4 the last. Y4 showed a substantial change by neutron irradiation as well as the properties was worse than others in the unirradiated state. However, Y5, which showed the best properties in unirradiated state, was also the best in the resistance for irradiation embrittlement and one can hardly detect the property change after irradiation. The weldment showed a reasonably good resistance to irradiation embrittlement while the unirradiated properties were worse than base metals. The RPV steels are all expected to meet the screening criteria of the USNRC codes and regulations during the end of plant life. 39 refs., 42 figs., 27 tabs. (Author)

  17. Drill core investigations from the TMI-2 pressure vessel. Final report

    International Nuclear Information System (INIS)

    Sturm, D.; Katerbau, K.H.; Maile, K.; Ruoff, H.

    1994-01-01

    For the evaluation of the results obtained in TMI-2 VIP and for the preparation of the continuing discussion in the OECD and of research measures in the national sphere but also for the appraisal of the effect of the results to date on safety philosophy and safety research in Germany, the present research project, inter alia, was commenced. In content was: a) Furtherance of the OECD-NEA-TMI-2 Vessel Investigation Project in dealing with the testing programme by active collaboration in the Programme Review Group, by participation in ad-hoc meetings on the question of specimen extraction, by advice on the conduct of metallographic, metallurgical and mechanical investigations on the specimens from the RPV bottom head and by assessment of the findings. b) Investigation of specimens from the bottom head of the TMI-2 reactor pressure vessel. c) Investigation of specimens from archive material. The investigations reach the widely agreed conclusion that during the accident a hot spot developed in the bottom head of the reactor in which for a time of about 30 minutes a maximum temperature of some 1100 C or greater than 900 C prevailed. Around this zone there is a region with temperatures higher than ca. 730 C (A 1 ) whilst the predominant portion of the head had not been heated beyond the 1 temperature. (orig.) [de

  18. Final report on development evaluation of Task Group 3 pressure tubes

    International Nuclear Information System (INIS)

    Fleck, R.G.; Price, E.G.; Cheadle, B.A.

    1983-11-01

    This report describes the production and evaluation of pressure tubes manufactured to the recommendations of Task Group 3 (TG3) of the Creep Engineering Design Plan. The Zr-2.5 wt percent Nb tubes were manufactured by modified production route to change their metallurgical structure and so reduce the in-service elongation rates. Three modified routes were investigated and a total of twenty-eight tubes produced. There were no difficulties in manufacture and the tubes satisfied the quality assurance and design specifications of reactor grade tubes. Metallurgical evaluation showed that the expected changes in microstructure had occurred but not to the extent anticipated. The TG3 tubes were found to have comparable properties to current tubes when tested for: tensile strength (irradiated and unirradiated); hydride cracking; stress to reorient hydrides; hydrogen diffusion; flaw tolerance; corrosion (irradiated and unirradiated); wear; rolled joint characteristics; irradiation creep and growth. Lower in-service elongation rates are expected for tubes produced by two of the modified routes

  19. Pressurized Fluidized-Bed Hydroretorting of eastern oil shales. Final report, June 1992--January 1993

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, M.J.; Mensinger, M.C.; Erekson, E.J.; Rue, D.M.; Lau, F.S. [Institute of Gas Technology, Chicago, IL (United States); Schultz, C.W.; Hatcher, W.E. [Alabama Univ., University, AL (United States). Mineral Resources Inst.; Parekh, B.K. [Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research; Bonner, W.P. [Tennessee Technological Univ., Cookeville, TN (United States)

    1993-03-01

    The Devonian oil shales of the Eastern United States are a significant domestic energy resource. The overall objective of the multi-year program, initiated in September 1987 by the US Department of Energy was to perform the research necessary to develop the pressurized fluidized-bed hydroretorting (PFH) process for producing oil from Eastern oil shales. The program also incorporates research on technologies in areas such as raw shale preparation, beneficiation, product separation and upgrading, and waste disposal that have the potential of improving the economics and/or environmental acceptability of recovering oil from oil shales using the PFH process. The program was divided into the following active tasks: Task 3 -- Testing of Process Improvement Concepts; Task 4 -- Beneficiation Research; Task 6 -- Environmental Data and Mitigation Analyses; and Task 9 -- Information Required for the National Environmental Policy Act. In order to accomplish all of the program objectives, tho Institute of Gas Technology (ICT), the prime contractor, worked with four other institutions: The University of Alabama/Mineral Resources Institute (MRI), the University of Alabama College of Engineering (UA), University of Kentucky Center for Applied Energy Research (UK-CAER), and Tennessee Technological University (TTU). This report presents the work performed by IGT from June 1, 1992 through January 31, 1993.

  20. Systolic pulmonary artery pressure assessed during routine exercise Doppler echocardiography: insights of a real-world setting in patients with elevated pulmonary pressures.

    Science.gov (United States)

    Korff, Susanne; Enders-Gier, Patricia; Uhlmann, Lorenz; Aurich, Matthias; Greiner, Sebastian; Hirschberg, Kristof; Katus, Hugo A; Mereles, Derliz

    2018-03-19

    Pulmonary hypertension is a marker of disease severity. Exercise Doppler echocardiography (EDE) has proven to be feasible and reliable to assess pulmonary pressure. Increase in systolic pulmonary artery pressure (sPAP) has diagnostic and prognostic value in controlled studies. However, its value when assessed during routine examination in patients with cardiopulmonary diseases and resting sPAP > 35 mmHg is not clearly defined. Clinical documentation and offline reevaluation of digitally stored EDE examinations of patients with appropriate clinical indications for EDE were analyzed. N = 278 patients with sPAP at rest > 35 mmHg met inclusion criteria. One patient was lost to follow-up. Mean age of patients was 72 ± 10 years, 178 (64%) of the study population were men. There were no relevant differences among survivors and non-survivors concerning comorbidities. Exercise performance (3.6 ± 1.2 vs. 4.9 ± 1.4 MET, p  45 mm (HR = 2.58, p  42 mmHg (HR = 1.94, p = 0.010) and ΔsPAP increase ≥ 0.23 mmHg/Watt (HF = 1.92, p = 0.010). After multivariate analysis, NYHA functional class III (HR = 2.35, p < 0.001), LA diameter (HR = 2.28, p = 0.003) and sPAP increase ≥ 0.23 mmHg/Watt (HF = 2.19, p = 0.002) remained significant predictors of mortality, whereas a double product (HR = 0.42, p = 0.005) was associated with better prognosis. sPAP assessment during routine EDE provides relevant prognostic information comparable to findings in studies in selected populations. A higher sPAP increase at lower exercise performance shows significant association with increased of mortality.

  1. Ratio of systolic blood pressure to left ventricular end-diastolic pressure at the time of primary percutaneous coronary intervention predicts in-hospital mortality in patients with ST-elevation myocardial infarction.

    Science.gov (United States)

    Sola, Michael; Venkatesh, Kiran; Caughey, Melissa; Rayson, Robert; Dai, Xuming; Stouffer, George A; Yeung, Michael

    2017-09-01

    To determine the ability of simple hemodynamic parameters obtained at the time of cardiac catheterization to predict in-hospital mortality following ST-elevation myocardial infarction (STEMI). Hemodynamic parameters measured at the time of primary percutaneous coronary intervention (PPCI) could potentially identify high-risk patients who would benefit from aggressive hemodynamic support in the Cardiac Catheterization laboratory. This is a retrospective single-center study of 219 consecutive patients with STEMI. Left ventricular end-diastolic pressure (LVEDP), systolic blood pressure (SBP), and aortic diastolic blood pressure were obtained after successful revascularization. The prognostic ability of LVEDP, pulse pressure, and SBP/LVEDP ratio were compared to major mortality risk scores. Patients had a mean age of 60 ±14 years, were predominantly white (73%), male (64%), with anterior wall infarcts in 39%. Comorbidities included diabetes mellitus (27%), heart failure (9%), and chronic kidney disease (7%). In-hospital mortality was 9%. Patients with SBP/LVEDP ≤ 4 had increased risk of in-hospital death (32% vs. 5.3%, P  4. The area under curve (AUC) for SBP/LVEDP ratio for in-hospital mortality (0.69) was more predictive than LVEDP (0.61, P = 0.04) or pulse pressure (0.55, P = 0.02) but similar to Shock Index (ratio of heart rate to SBP) and Modified Shock Index (ratio of HR to mean arterial pressure). An SBP/LVEDP ratio ≤ 4 identified a group of STEMI patients at high risk of in-hospital death. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Development of a self-consistent model of dust grain charging at elevated pressures using the method of moments

    International Nuclear Information System (INIS)

    Filippov, A.V.; Dyatko, N.A.; Pal', A.F.; Starostin, A.N.

    2003-01-01

    A model of dust grain charging is constructed using the method of moments. The dust grain charging process in a weakly ionized helium plasma produced by a 100-keV electron beam at atmospheric pressure is studied theoretically. In simulations, the beam current density was varied from 1 to 10 6 μA/cm 2 . It is shown that, in a He plasma, dust grains of radius 5 μm and larger perturb the electron temperature only slightly, although the reduced electric field near the grain reaches 8 Td, the beam current density being 10 6 μA/cm 2 . It is found that, at distances from the grain that are up to several tens or hundreds of times larger than its radius, the electron and ion densities are lower than their equilibrium values. Conditions are determined under which the charging process may be described by a model with constant electron transport coefficients. The dust grain charge is shown to be weakly affected by secondary electron emission. In a beam-produced helium plasma, the dust grain potential calculated in the drift-diffusion model is shown to be close to that calculated in the orbit motion limited model. It is found that, in the vicinity of a body perturbing the plasma, there may be no quasineutral plasma presheath with an ambipolar diffusion of charged particles. The conditions for the onset of this presheath in a beam-produced plasma are determined

  3. The CHIPS Randomized Controlled Trial (Control of Hypertension in Pregnancy Study): Is Severe Hypertension Just an Elevated Blood Pressure?

    Science.gov (United States)

    Magee, Laura A; von Dadelszen, Peter; Singer, Joel; Lee, Terry; Rey, Evelyne; Ross, Susan; Asztalos, Elizabeth; Murphy, Kellie E; Menzies, Jennifer; Sanchez, Johanna; Gafni, Amiram; Helewa, Michael; Hutton, Eileen; Koren, Gideon; Lee, Shoo K; Logan, Alexander G; Ganzevoort, Wessel; Welch, Ross; Thornton, Jim G; Moutquin, Jean-Marie

    2016-11-01

    To determine whether clinical outcomes differed by occurrence of severe hypertension in the international CHIPS trial (Control of Hypertension in Pregnancy Study), adjusting for the interventions of "less tight" (target diastolic blood pressure [dBP] 100 mm Hg) versus "tight" control (target dBP 85 mm Hg). In this post-hoc analysis of CHIPS data from 987 women with nonsevere nonproteinuric preexisting or gestational hypertension, mixed effects logistic regression was used to compare the following outcomes according to occurrence of severe hypertension, adjusting for allocated group and the influence of baseline factors: CHIPS primary (perinatal loss or high-level neonatal care for >48 hours) and secondary outcomes (serious maternal complications), birth weight hypertension that was associated with all outcomes examined except for maternal readmission (P=0.20): CHIPS primary outcome, birth weight hypertension and serious maternal complications was seen only in less tight control (P=0.02). Adjustment for preeclampsia (464, 47.3%) did not negate the relationship between severe hypertension and the CHIPS primary outcome (Phypertension is a risk marker for adverse maternal and perinatal outcomes, independent of BP control or preeclampsia co-occurrence. URL: http://pre-empt.cfri.ca/. Unique identifier: ISRCTN 71416914. URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01192412. © 2016 The Authors.

  4. Lipocalin 2 Imparts Selective Pressure on Bacterial Growth in the Bladder and Is Elevated in Women with Urinary Tract Infection

    Science.gov (United States)

    Steigedal, Magnus; Marstad, Anne; Haug, Markus; Damås, Jan K.; Strong, Roland K.; Roberts, Pacita L.; Himpsl, Stephanie D.; Stapleton, Ann; Hooton, Thomas M.; Mobley, Harry L. T.; Hawn, Thomas R.

    2014-01-01

    Competition for iron is a critical component of successful bacterial infections, but the underlying in vivo mechanisms are poorly understood. We have previously demonstrated that lipocalin 2 (LCN2) is an innate immunity protein that binds to bacterial siderophores and starves them for iron, thus representing a novel host defense mechanism to infection. In the present study we show that LCN2 is secreted by the urinary tract mucosa and protects against urinary tract infection (UTI). We found that LCN2 was expressed in the bladder, ureters, and kidneys of mice subject to UTI. LCN2 was protective with higher bacterial numbers retrieved from bladders of Lcn2-deficient mice than from wild-type mice infected with the LCN2-sensitive Escherichia coli strain H9049. Uropathogenic E. coli mutants in siderophore receptors for salmochelin, aerobactin, or yersiniabactin displayed reduced fitness in wild-type mice, but not in mice deficient of LCN2, demonstrating that LCN2 imparts a selective pressure on bacterial growth in the bladder. In a human cohort of women with recurrent E. coli UTIs, urine LCN2 levels were associated with UTI episodes and with levels of bacteriuria. The number of siderophore systems was associated with increasing bacteriuria during cystitis. Our data demonstrate that LCN2 is secreted by the urinary tract mucosa in response to uropathogenic E. coli challenge and acts in innate immune defenses as a colonization barrier that pathogens must overcome to establish infection. PMID:25398327

  5. Intracranial Pressure Elevation 24 Hours after Ischemic Stroke in Aged Rats is Prevented by Early, Short Hypothermia Treatment

    Directory of Open Access Journals (Sweden)

    Lucy Anne Murtha

    2016-05-01

    Full Text Available Stroke is predominantly a senescent disease, yet most preclinical studies investigate treatment in young animals. We recently demonstrated that short-duration hypothermia-treatment completely prevented the dramatic intracranial pressure (ICP rise seen post-stroke in young rats. Here, our aim was to investigate whether a similar ICP rise occurs in aged rats and to determine whether short-duration hypothermia is an effective treatment in aged animals. Experimental Middle Cerebral Artery occlusion (MCAo - 3 hour occlusion was performed on male Wistar rats aged 19-20 months. At one hour after stroke-onset, rats were randomized to 2.5 hours hypothermia-treatment (32.5 °C or normothermia (37 °C. ICP was monitored at baseline, for 3.5 hours post-occlusion, and at 24 hours post-stroke. Infarct and edema volumes were calculated from histology. Baseline pre-stroke ICP was 11.2 ± 3.3 mmHg across all animals. Twenty-four hours post-stroke, ICP was significantly higher in normothermic animals compared to hypothermia-treated animals (27.4 ± 18.2 mmHg vs. 8.0 ± 5.0 mmHg, p = 0.03. Infarct and edema volumes were not significantly different between groups. These data demonstrate ICP may also increase 24 hours post-stroke in aged rats, and that short-duration hypothermia treatment has a profound and sustained preventative effect. These findings may have important implications for the use of hypothermia in clinical trials of aged stroke patients.

  6. The solubility of gold in H 2 O-H 2 S vapour at elevated temperature and pressure

    Science.gov (United States)

    Zezin, Denis Yu.; Migdisov, Artashes A.; Williams-Jones, Anthony E.

    2011-09-01

    This experimental study sheds light on the complexation of gold in reduced sulphur-bearing vapour, specifically, in H 2O-H 2S gas mixtures. The solubility of gold was determined in experiments at temperatures of 300, 350 and 365 °C and reached 2.2, 6.6 and 6.3 μg/kg, respectively. The density of the vapour varied from 0.02 to 0.22 g/cm 3, the mole fraction of H 2S varied from 0.03 to 0.96, and the pressure in the cell reached 263 bar. Statistically significant correlations of the amount of gold dissolved in the fluid with the fugacity of H 2O and H 2S permit the experimental data to be fitted to a solvation/hydration model. According to this model, the solubility of gold in H 2O-H 2S gas mixtures is controlled by the formation of sulphide or bisulphide species solvated by H 2S or H 2O molecules. Formation of gold sulphide species is favoured statistically over gold bisulphide species and thus the gold is interpreted to dissolve according to reactions of the form: Au(s)+(n+1)HS(g)=AuS·(HS)n(g)+H(g) Au(s)+HS(g)+mHO(g)=AuS·(HO)m(g)+H(g) Equilibrium constants for Reaction (A1) and the corresponding solvation numbers ( K A1 and n) were evaluated from the study of Zezin et al. (2007). The equilibrium constants as well as the hydration numbers for Reaction (A2) ( K A2 and m) were adjusted simultaneously by a custom-designed optimization algorithm and were tested statistically. The resulting values of log K A2 and m are -15.3 and 2.3 at 300 and 350 °C and -15.1 and 2.2 at 365 °C, respectively. Using the calculated stoichiometry and stability of Reactions (A1) and (A2), it is now possible to quantitatively evaluate the contribution of reduced sulphur species to the transport of gold in aqueous vapour at temperatures up to 365 °C. This information will find application in modelling gold ore-forming processes in vapour-bearing magmatic hydrothermal systems, notably those of epithermal environments.

  7. Apparatus to measure vapor pressure, differential vapor pressure, liquid molar volume, and compressibility of liquids and solutions to the critical point. Vapor pressures, molar volumes, and compressibilities of protiobenzene and deuteriobenzene at elevated temperatures

    International Nuclear Information System (INIS)

    Kooner, Z.S.; Van Hook, W.A.

    1986-01-01

    An apparatus designed to measure vapor pressure differences between two similar liquids, such as isotopic isomers, or between a solution and its reference solvent at temperatures and pressures extending to the critical point is described. Vapor-phase volume is minimized and pressure is transmitted to the transducer through the liquid, thereby avoiding several experimental difficulties. Liquid can be injected into the heated part of the system by volumetrically calibrated screw injectors, thus permitting measurements of liquid molar volume, compressibility, and expansivity. The addition of a high-pressure circulating pump and injection valve allows the apparatus to be employed as a continuous dilution differential vapor pressure apparatus for determining partial molar free energies of solution. In the second part of the paper data on the vapor pressure, molar volume, compressibility, and expansivity and their isotope effects for C 6 H 6 and C 6 D 6 from room temperature to near the critical temperature are reported

  8. Can adverse maternal and perinatal outcomes be predicted when blood pressure becomes elevated? Secondary analyses from the CHIPS (Control of Hypertension In Pregnancy Study) randomized controlled trial.

    Science.gov (United States)

    Magee, Laura A; von Dadelszen, Peter; Singer, Joel; Lee, Terry; Rey, Evelyne; Ross, Susan; Asztalos, Elizabeth; Murphy, Kellie E; Menzies, Jennifer; Sanchez, Johanna; Gafni, Amiram; Gruslin, Andrée; Helewa, Michael; Hutton, Eileen; Lee, Shoo K; Logan, Alexander G; Ganzevoort, Wessel; Welch, Ross; Thornton, Jim G; Moutquin, Jean Marie

    2016-07-01

    For women with chronic or gestational hypertension in CHIPS (Control of Hypertension In Pregnancy Study, NCT01192412), we aimed to examine whether clinical predictors collected at randomization could predict adverse outcomes. This was a planned, secondary analysis of data from the 987 women in the CHIPS Trial. Logistic regression was used to examine the impact of 19 candidate predictors on the probability of adverse perinatal (pregnancy loss or high level neonatal care for >48 h, or birthweight hypertension, preeclampsia, or delivery at blood pressure within 1 week before randomization. Continuous variables were represented continuously or dichotomized based on the smaller p-value in univariate analyses. An area-under-the-receiver-operating-curve (AUC ROC) of ≥0.70 was taken to reflect a potentially useful model. Point estimates for AUC ROC were hypertension (0.70, 95% CI 0.67-0.74) and delivery at hypertension develop an elevated blood pressure in pregnancy, or formerly normotensive women develop new gestational hypertension, maternal and current pregnancy clinical characteristics cannot predict adverse outcomes in the index pregnancy. © 2016 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).

  9. Exposure to a high-fat diet during development alters leptin and ghrelin sensitivity and elevates renal sympathetic nerve activity and arterial pressure in rabbits.

    Science.gov (United States)

    Prior, Larissa J; Davern, Pamela J; Burke, Sandra L; Lim, Kyungjoon; Armitage, James A; Head, Geoffrey A

    2014-02-01

    Exposure to maternal obesity or a maternal diet rich in fat during development may have adverse outcomes in offspring, such as the development of obesity and hypertension. The present study examined the effect of a maternal high-fat diet (m-HFD) on offspring blood pressure and renal sympathetic nerve activity, responses to stress, and sensitivity to central administration of leptin and ghrelin. Offspring of New Zealand white rabbits fed a 13% HFD were slightly heavier than offspring from mothers fed a 4% maternal normal fat diet (Pfat pad mass (P=0.015). Mean arterial pressure, heart rate, and renal sympathetic nerve activity at 4 months of age were 7%, 7%, and 24% greater, respectively (Pfat diet rabbits, and the renal sympathetic nerve activity response to airjet stress was enhanced in the m-HFD group. m-HFD offspring had markedly elevated pressor and renal sympathetic nerve activity responses to intracerebroventricular leptin (5-100 µg) and enhanced sympathetic responses to intracerebroventricular ghrelin (1-5 nmol). In contrast, there was resistance to the anorexic effects of intracerebroventricular leptin and less neuronal activation as detected by Fos immunohistochemistry in the arcuate (-57%; Pfat diet rabbits. We conclude that offspring from mothers consuming an HFD exhibit an adverse cardiovascular profile in adulthood because of altered central hypothalamic sensitivity to leptin and ghrelin.

  10. Cytochrome P450 (CYP2D6) genotype is associated with elevated systolic blood pressure in preterm infants after discharge from the neonatal intensive care unit.

    Science.gov (United States)

    Dagle, John M; Fisher, Tyler J; Haynes, Susan E; Berends, Susan K; Brophy, Patrick D; Morriss, Frank H; Murray, Jeffrey C

    2011-07-01

    To determine genetic and clinical risk factors associated with elevated systolic blood pressure (ESBP) in preterm infants after discharge from the neonatal intensive care unit (NICU). A convenience cohort of infants born at 90th percentile for term infants). Genetic testing identified alleles associated with ESBP. Multivariate logistic regression analysis was performed for the outcome ESBP, with clinical characteristics and genotype as independent variables. Predictors of ESBP were cytochrome P450, family 2, subfamily D, polypeptide 6 (CYP2D6) (rs28360521) CC genotype (OR, 2.92; 95% CI, 1.48-5.79), adjusted for outpatient oxygen therapy (OR, 4.53; 95% CI, 2.23-8.81) and history of urinary tract infection (OR, 4.68; 95% CI, 1.47-14.86). Maximum SBP was modeled by multivariate linear regression analysis: maximum SBP=84.8 mm Hg + 6.8 mm Hg if cytochrome P450, family 2, subfamily D, polypeptide 6 (CYP2D6) CC genotype + 6.8 mm Hg if discharged on supplemental oxygen + 4.4 mm Hg if received inpatient glucocorticoids (P=.0002). ESBP is common in preterm infants with residual lung disease after discharge from the NICU. This study defines clinical factors associated with ESBP, identifies a candidate gene for further testing, and supports the recommendation to monitor blood pressure before age 3 years, as is suggested for term infants. Copyright © 2011 Mosby, Inc. All rights reserved.

  11. Study of elevated temperature design standard against thermal loads

    International Nuclear Information System (INIS)

    Kasahara, Naoto; Asayama, Tai; Morishita, Masaki

    2001-01-01

    Elevated temperature components must be designed against both pressure and thermal loads. In the case of sodium circuits of fast breeder reactors, a restriction from the pressure load becomes small because of the high boiling point of sodium. Design approaches for thermal loads (displacement-controlled) are compared with those against pressure loads (load-controlled). Considering differences between those two approaches, a concept of the elevated temperature design standard that takes the nature of thermal loads fully into account is proposed. This concept is a basis of load evaluation techniques and an inelastic analysis guide, that are being developed. Finally, problems and plans to realize the above concept are discussed. (author)

  12. Short- to long-term results of Ahmed glaucoma valve in the management of elevated intraocular pressure in patients with pediatric uveitis.

    Science.gov (United States)

    Eksioglu, Umit; Yakin, Mehmet; Sungur, Gulten; Satana, Banu; Demirok, Gulizar; Balta, Ozgur; Ornek, Firdevs

    2017-06-01

    The aim of this study was to evaluate the long-term outcome of Ahmed glaucoma valve (AGV) implant for elevated intraocular pressure (IOP) in pediatric patients with uveitis. This was a retrospective chart review. The study included 16 eyes (11 children) with uveitis. Success was defined as having IOP between 6 and 21 mm Hg with (qualified success) or without (complete success) antiglaucoma medications and without the need for further glaucoma or tube extraction surgery. Mean age of patients at the time of AGV implantation was 14.19 ± 3.25 years. AGV implantation was the first glaucoma surgical procedure in 12 eyes (75%). Average postoperative follow-up period was 64.46 ± 33.56 months. Mean preoperative IOP was 33.50 ± 7.30 mm Hg versus 12.69 ± 3.20 mm Hg at the last follow-up visit (p < 0.001). Three eyes (18.7%) were determined as cases of "failure" because of tube removal in 2 eyes and a second AGV implantation in 1 eye. The cumulative probability of complete success was 68.8% at 6 months, 56.3% at 12 months, 49.2% at 36 months, 42.2% at 48 months, and 35.2% at 84 months, and the cumulative probability of eyes without complication was 75.0% at 6 months, 66.7% at 24 months, 58.3% at 36 months, 48.6% at 48 months and 24.3% at 108 months based on Kaplan-Meier survival analysis. Although AGV implant is an effective choice in the management of elevated IOP in pediatric uveitis, antiglaucoma medications are frequently needed for control of IOP. Tube exposure is an important complication in the long term. Differential diagnosis between relapse of uveitis and endophthalmitis is important in patients who received AGV implantation. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  13. Impact of long-term burden of excessive adiposity and elevated blood pressure from childhood on adulthood left ventricular remodeling patterns: the Bogalusa Heart Study.

    Science.gov (United States)

    Lai, Chin-Chih; Sun, Dianjianyi; Cen, Ruiqi; Wang, Jian; Li, Shengxu; Fernandez-Alonso, Camilo; Chen, Wei; Srinivasan, Sathanur R; Berenson, Gerald S

    2014-10-14

    Cardiovascular risk factors are associated with left ventricular hypertrophy (LVH), but little is known regarding related impact of longitudinal measures of childhood adiposity and LV hemodynamic variables. The aim of this study was to examine the impact of cumulative long-term burden and trends of excessive adiposity and elevated blood pressure (BP) during childhood on adulthood LVH and LV geometric remodeling patterns. This longitudinal study consisted of 1,061 adults, age 24 to 46 years, who had been examined 4 or more times for body mass index (BMI) and BP starting in childhood, with a mean follow-up of 28.0 years. The area under the curve (AUC) was calculated as a measure of long-term burden (total AUC) and trends (incremental AUC) of BMI and BP from childhood to adulthood. Four LV geometric types were defined-normal, concentric remodeling (CR), eccentric hypertrophy (EH), and concentric hypertrophy (CH)-all on the basis of LV mass indexed for body height (m(2.7)) and relative wall thickness. Higher values of BMI and systolic and diastolic BP in childhood and adulthood, as well as total AUC and incremental AUC, were all significantly associated with higher LV mass index and LVH, adjusted for race, sex, and age. In addition, higher values of BMI and BP in childhood and adulthood, total AUC, and incremental AUC were significantly associated with EH and CH but not with CR. Importantly, all of these measures of BMI had a consistently and significantly greater influence on EH than did measures of BP. These findings indicate that the adverse influence of excessive adiposity and elevated BP levels on LVH begins in childhood. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  14. Inhibition on Apoptosis Induced by Elevated Hydrostatic Pressure in Retinal Ganglion Cell-5 via Laminin Upregulating β1-integrin/Focal Adhesion Kinase/Protein Kinase B Signaling Pathway.

    Science.gov (United States)

    Li, Yi; Chen, Yan-Ming; Sun, Ming-Ming; Guo, Xiao-Dan; Wang, Ya-Chen; Zhang, Zhong-Zhi

    2016-04-20

    Glaucoma is a progressive optic neuropathy characterized by degeneration of neurons due to loss of retinal ganglion cells (RGCs). High intraocular pressure (HIOP), the main risk factor, causes the optic nerve damage. However, the precise mechanism of HIOP-induced RGC death is not yet completely understood. This study was conducted to determine apoptosis of RGC-5 cells induced by elevated hydrostatic pressures, explore whether laminin is associated with apoptosis under pressure, whether laminin can protect RGCs from apoptosis and affirm the mechanism that regulates the process of RGCs survival. RGC-5 cells were exposed to 0, 20, 40, and 60 mmHg in a pressurized incubator for 6, 12, and 24 h, respectively. The effect of elevated hydrostatic pressure on RGC-5 cells was measured by Annexin V-fluorescein isothiocyanate/propidium iodide staining, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and Western blotting of cleaved caspase-3 protein. Location and expression of laminin were detected by immunofluorescence. The expression of β1-integrin, phosphorylation of focal adhesion kinase (FAK) and protein kinase B (PKB, or AKT) were investigated with real-time polymerase chain reaction and Western blotting analysis. Elevated hydrostatic pressure induced apoptosis in cultured RGC-5 cells. Pressure with 40 mmHg for 24 h induced a maximum apoptosis. Laminin was declined in RGC-5 cells after exposing to 40 mmHg for 24 h. After pretreating with laminin, RGC-5 cells survived from elevated pressure. Furthermore, β1-integrin and phosphorylation of FAK and AKT were increased compared to 40 mmHg group. The data show apoptosis tendency of RGC-5 cells with elevated hydrostatic pressure. Laminin can protect RGC-5 cells against high pressure via β1-integrin/FAK/AKT signaling pathway. These results suggest that the decreased laminin of RGC-5 cells might be responsible for apoptosis induced by elevated hydrostatic pressure, and laminin or activating β1-integrin

  15. Stand-alone polarization-modulation infrared reflection absorption spectroscopy instrument optimized for the study of catalytic processes at elevated pressures

    Science.gov (United States)

    Kestell, John D.; Mudiyanselage, Kumudu; Ye, Xinyi; Nam, Chang-Yong; Stacchiola, Dario; Sadowski, Jerzy; Boscoboinik, J. Anibal

    2017-10-01

    This paper describes the design and construction of a compact, "user-friendly" polarization-modulation infrared reflection absorption spectroscopy (PM-IRRAS) instrument at the Center for Functional Nanomaterials (CFN) of Brookhaven National Laboratory, which allows studying surfaces at pressures ranging from ultra-high vacuum to 100 Torr. Surface infrared spectroscopy is ideally suited for studying these processes as the vibrational frequencies of the IR chromophores are sensitive to the nature of the bonding environment on the surface. Relying on the surface selection rules, by modulating the polarization of incident light, it is possible to separate the contributions from the isotropic gas or solution phase, from the surface bound species. A spectral frequency range between 1000 cm-1 and 4000 cm-1 can be acquired. While typical spectra with a good signal to noise ratio can be obtained at elevated pressures of gases in ˜2 min at 4 cm-1 resolution, we have also acquired higher resolution spectra at 0.25 cm-1 with longer acquisition times. By way of verification, CO uptake on a heavily oxidized Ru(0001) sample was studied. As part of this test study, the presence of CO adsorbed on Ru bridge sites was confirmed, in agreement with previous ambient pressure X ray photoelectron spectroscopy studies. In terms of instrument performance, it was also determined that the gas phase contribution from CO could be completely removed even up to pressures close to 100 Torr. A second test study demonstrated the use of the technique for studying morphological properties of a spin coated polymer on a conductive surface. Note that this is a novel application of this technique. In this experiment, the polarization of incident light was modulated manually (vs. through a photoelastic modulator). It was demonstrated, in good agreement with the literature, that the polymer chains preferentially lie parallel with the surface. This PM-IRRAS system is small, modular, and easily

  16. Inter-arm blood pressure difference and mortality: a cohort study in an asymptomatic primary care population at elevated cardiovascular risk.

    Science.gov (United States)

    Clark, Christopher E; Taylor, Rod S; Butcher, Isabella; Stewart, Marlene Cw; Price, Jackie; Fowkes, F Gerald R; Shore, Angela C; Campbell, John L

    2016-05-01

    Differences in blood pressure between arms are associated with increased cardiovascular mortality in cohorts with established vascular disease or substantially elevated cardiovascular risk. To explore the association of inter-arm difference (IAD) with mortality in a community-dwelling cohort that is free of cardiovascular disease. Cohort analysis of a randomised controlled trial in central Scotland, from April 1998 to October 2008. Volunteers from Lanarkshire, Glasgow, and Edinburgh, free of pre-existing vascular disease and with an ankle-brachial index ≤0.95, had systolic blood pressure measured in both arms at recruitment. Inter-arm blood pressure differences were calculated and examined for cross-sectional associations and differences in prospective survival. Outcome measures were cardiovascular events and all-cause mortality during mean follow-up of 8.2 years. Based on a single pair of measurements, 60% of 3350 participants had a systolic IAD ≥5 mmHg and 38% ≥10 mmHg. An IAD ≥5 mmHg was associated with increased cardiovascular mortality (adjusted hazard ratio [HR] 1.91, 95% confidence interval [CI] = 1.19 to 3.07) and all-cause mortality (adjusted HR 1.44, 95% CI = 1.15 to 1.79). Within the subgroup of 764 participants who had hypertension, IADs of ≥5 mmHg or ≥10 mmHg were associated with both cardiovascular mortality (adjusted HR 2.63, 95% CI = 0.97 to 7.02, and adjusted HR 2.96, 95% CI = 1.27 to 6.88, respectively) and all-cause mortality (adjusted HR 1.67, 95% CI = 1.05 to 2.66, and adjusted HR 1.63, 95% CI = 1.06 to 2.50, respectively). IADs ≥15 mmHg were not associated with survival differences in this population. Systolic IADs in blood pressure are associated with increased risk of cardiovascular events, including mortality, in a large cohort of people free of pre-existing vascular disease. © British Journal of General Practice 2016.

  17. Blood Pressure Test

    Science.gov (United States)

    ... pressure monitors may have some limitations. Tracking your blood pressure readings It can be helpful in diagnosing or ... more Stage 2 high blood pressure (hypertension) Elevated blood pressure and stages 1 and 2 high blood pressure ( ...

  18. Influence of gamma irradiation on the deterioration of reactor pressure vessel materials and on reactor dosimetry measurements. Final report

    International Nuclear Information System (INIS)

    Boehmer, B.; Konheiser, J.; Kumpf, H.; Noack, K.; Vladimirov, P.

    2002-10-01

    Radiation embrittlement of pressure vessel steel in mixed neutron-gamma fields is mostly determined by neutrons, but in some cases also by gamma-radiation. Depending on the reactor type, gamma radiation can influence evaluations of lead factors of surveillance specimens, effect the interpretation of results of irradiation experiments and finally, it can result in changed pressure vessel lifetime evaluations. The project aimed at the evaluation of the importance of gamma radiation for RPV steel damage for several types of light-water reactors. Absolute neutron and gamma fluence rate spectra had been calculated for the Russian PWR types VVER-440 and two core loading variants of VVER-1000, for a German 1300 MW PWR and a German 900 MW BWR. Based on the calculated spectra several flux integrals and radiation damage parameters were derived for the region of the azimuthal flux maxima in the mid-planes for different radial positions between core and biological shield, especially, at the inner and outer surfaces of the PV walls, at the (1/4)-PV-thickness and at the surveillance positions. Fissionable materials are often used as activation detectors for neutron fluence measurements. To get the real value the analysis demands to take into account the gamma induced fissions. Therefore, the part of these fissions in the total number of fissions was estimated for the detector reactions 237 Np(n,f) and 238 U(n,f) in the calculated neutron/gamma fields. It has been found that considerable corrections of the neutron fluence measurements can be necessary, especially in case of 238 U(n,f). Most of the calculations were performed using a three-dimensional synthesis of 2D/1D-flux distributions obtained by the S N -code DORT with the BUGLE-96T group cross-section library. (orig.) [de

  19. New method for control of biological fouling in pipelines based on elevated partial pressures of carbon dioxide or combustion exhaust gases.

    Energy Technology Data Exchange (ETDEWEB)

    B.J. Watten; R.E. Sears; R.F. Bumgardner [U.S. Geological Survey - Leetown Science Center, Kearneysville, WV (United States)

    2005-07-01

    Zebra mussels (Dreissena polymorpha) and Asian clams (Corbicula fluminea) are major macro fouling species of water conduits used in industrial and power station raw water/condensor systems. Control typically involves manual scraping and use of thermal treatment, deoxygenation or biocides. The costs of control and system damage resulting from fouling in the United States alone have been estimated at $1 billion/year. There is a pressing need for new economical and safe control strategies. Aquatic species in general are intolerant to increases in PCO{sub 2} given its effect on water, blood and hemolymph pH. These species are also sensitive to increases in elevated total dissolved gas pressure. The gas bubble disease that develops following exposure can, as with CO{sub 2} exposure, lead to mortality. We are exploiting this sensitivity by developing a control method based on manipulation of PCO{sub 2} or power plant exhaust gas (CO{sub 2}, 14%; SO{sub 2}, 0.3%), i.e., the supersaturation of hemolymph and tissues with gas followed by an induced (short term) pressure release designed to induce formation of gas emboli. SO{sub 2} present in stack gas acts with CO{sub 2} to reduce water and hemolymph pH so as to reduce required exposure periods. System effluents are degassed, CO{sub 2} recovered and pH adjusted if needed with alkaline reagents. Test results indicate the new process is effective at controlling C. fluminea as well as other target species, including crustaceans and fish. Required exposure periods (LT50) are short and decrease with increasing gas supersaturation levels. Gas recovery and reuse methods developed have reduced gas requirements by 85% making the method attractive economically and environmentally. 40 refs., 8 figs., 1 tab.

  20. Analysis of the association between periportal low attenuation, as seen on CT, after blunt abdominal trauma, and elevated central venous pressure

    International Nuclear Information System (INIS)

    Lee, Jae Hung; Lee, Hyeon Kyeong; Lee, Chae Kyeong; Ku, Kwan Min; Lee, Sung Woo; Kim, Miu Woon; Ahn, Woo Sub; Yoon, Ji Young

    1999-01-01

    To assess the causes of periportal low attenuation, as seen on CT, in patients with blunt abdominal trauma. From among 812 patients who underwent abdominal CT after blunt abdominal trauma, we retrospectively analysed the findings in 124 with evidence of periportal low attenuation. Among these, hepatic injury was noted in only 87. The presence or absence, and extent of hepatic injury, and of periportal low attenuation, as seen on CT, were carefully evaluated. In each case, the ratio of the transverse diameter of the inferior vena cava(IVC) to the aorta at the level of the right adrenal gland provided an indirect measurement of central venous pressure ; for control purposes, the ratio was also obtained in 21 non-traumatic patients with no abnormal abdominal CT findings. Of the 87 patients with hepatic injury, 46 showed no periportal low attenuation, and average value of the ratio between the IVC and aorta was 1.16±0.12, while the remaining 41 patients showed periportal low attenuation with a ratio of 1.51±0.21(p<0.05). In the 37 patients with periportal low attenuation but no evidence of concomitant hepatic injury, the average ratio was 1.52±0.25, while in 21 non-traumatic patients it was 1.15±0.16. For resuscitation, all patients had received 0.5-5.0 litre of IV fluid therapy before CT, and at the time of CT, were normotensive. Rapidly elevated central venous pressure following massive IV infusion therapy in patients with blunt abdominal trauma can be one of the causes of periportal low attenuation, as seen on CT

  1. Analysis of the association between periportal low attenuation, as seen on CT, after blunt abdominal trauma, and elevated central venous pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Hung; Lee, Hyeon Kyeong; Lee, Chae Kyeong; Ku, Kwan Min; Lee, Sung Woo; Kim, Miu Woon; Ahn, Woo Sub [Dongguk Univ. College of Medicine, Pohang (Korea, Republic of); Yoon, Ji Young [Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-01-01

    To assess the causes of periportal low attenuation, as seen on CT, in patients with blunt abdominal trauma. From among 812 patients who underwent abdominal CT after blunt abdominal trauma, we retrospectively analysed the findings in 124 with evidence of periportal low attenuation. Among these, hepatic injury was noted in only 87. The presence or absence, and extent of hepatic injury, and of periportal low attenuation, as seen on CT, were carefully evaluated. In each case, the ratio of the transverse diameter of the inferior vena cava(IVC) to the aorta at the level of the right adrenal gland provided an indirect measurement of central venous pressure ; for control purposes, the ratio was also obtained in 21 non-traumatic patients with no abnormal abdominal CT findings. Of the 87 patients with hepatic injury, 46 showed no periportal low attenuation, and average value of the ratio between the IVC and aorta was 1.16{+-}0.12, while the remaining 41 patients showed periportal low attenuation with a ratio of 1.51{+-}0.21(p<0.05). In the 37 patients with periportal low attenuation but no evidence of concomitant hepatic injury, the average ratio was 1.52{+-}0.25, while in 21 non-traumatic patients it was 1.15{+-}0.16. For resuscitation, all patients had received 0.5-5.0 litre of IV fluid therapy before CT, and at the time of CT, were normotensive. Rapidly elevated central venous pressure following massive IV infusion therapy in patients with blunt abdominal trauma can be one of the causes of periportal low attenuation, as seen on CT.

  2. Spots on electrodes and images of a gap during pulsed discharges in an inhomogeneous electric field at elevated pressures of air, nitrogen and argon

    International Nuclear Information System (INIS)

    Shao, Tao; Yang, Wenjin; Zhang, Cheng; Yan, Ping; Tarasenko, Victor F; Beloplotov, Dmitry V; Lomaev, Mikhail I; Sorokin, Dmitry A

    2014-01-01

    Pulsed discharge in a nonuniform electric field accompanied by the appearance of bright spots due to explosive electron emission on electrodes has been investigated. The experiments were carried out using three experimental setups, a voltage pulse duration at a matched load of 2 ns, 40 ns, and 130 ns, respectively. Data on the formation of electrode spots during diffuse discharges in tube-plate or needle-plate gap configurations filled with gases at elevated pressures (air, nitrogen and argon) were obtained. It was found that in the air and other gases, bright spots arise on the flat electrode, and on the negative polarity of the electrode with a small radius of curvature, during the direction change of the current through the gap and the increase of the voltage pulse duration. It was shown that at the positive polarity of the electrode with a small radius of curvature, bright spots on the flat electrode arise due to the participation of the dynamic displacement current in the gap conductance. (paper)

  3. Exposure to a high-fat diet alters leptin sensitivity and elevates renal sympathetic nerve activity and arterial pressure in rabbits.

    Science.gov (United States)

    Prior, Larissa J; Eikelis, Nina; Armitage, James A; Davern, Pamela J; Burke, Sandra L; Montani, Jean-Pierre; Barzel, Benjamin; Head, Geoffrey A

    2010-04-01

    The activation of the sympathetic nervous system through the central actions of the adipokine leptin has been suggested as a major mechanism by which obesity contributes to the development of hypertension. However, direct evidence for elevated sympathetic activity in obesity has been limited to muscle. The present study examined the renal sympathetic nerve activity and cardiovascular effects of a high-fat diet (HFD), as well as the changes in the sensitivity to intracerebroventricular leptin. New Zealand white rabbits fed a 13.5% HFD for 4 weeks showed modest weight gain but a 2- to 3-fold greater accumulation of visceral fat compared with control rabbits. Mean arterial pressure, heart rate, and plasma norepinephrine concentration increased by 8%, 26%, and 87%, respectively (Pdiet rabbits and was correlated to plasma leptin (r=0.87; Pfat accumulation through consumption of a HFD leads to marked sympathetic activation, which is related to increased responsiveness to central sympathoexcitatory effects of leptin. The paradoxical reduction in hypothalamic neuronal activation by leptin suggests a marked "selective leptin resistance" in these animals.

  4. Normal pregnancy: mechanisms underlying the paradox of a ouabain-resistant state with elevated endogenous ouabain, suppressed arterial sodium calcium exchange, and low blood pressure

    Science.gov (United States)

    Jacobs, Brandiese E.; Liu, Yong; Pulina, Maria V.; Golovina, Vera A.

    2012-01-01

    Endogenous cardiotonic steroids (CTS) raise blood pressure (BP) via vascular sodium calcium exchange (NCX1.3) and transient receptor-operated channels (TRPCs). Circulating CTS are superelevated in pregnancy-induced hypertension and preeclampsia. However, their significance in normal pregnancy, where BP is low, is paradoxical. Here we test the hypothesis that vascular resistance to endogenous ouabain (EO) develops in normal pregnancy and is mediated by reduced expression of NCX1.3 and TRPCs. We determined plasma and adrenal levels of EO and the impact of exogenous ouabain in pregnancy on arterial expression of Na+ pumps, NCX1.3, TRPC3, and TRPC6 and BP. Pregnant (embryonic day 4) and nonpregnant rats received infusions of ouabain or vehicle. At 14–16 days, tissues and plasma were collected for blotting and EO assay by radioimmunoassay (RIA), liquid chromatography (LC)-RIA, and LC-multidimensional mass spectrometry (MS3). BP (−8 mmHg; P vs. nonpregnant (0.6 ± 0.08 nM; P endogenous and exogenous ouabain is mediated by suppressed NCX1.3 and reduced sensitivity of events downstream of Ca2+ entry. The mechanisms of EO resistance and the impaired fetal and placental growth due to elevated ouabain may be important in pregnancy-induced hypertension (PIH) and preeclampsia (PE). PMID:22245773

  5. DNS of Low-Pressure Turbine Cascade Flows with Elevated Inflow Turbulence Using a Discontinuous-Galerkin Spectral-Element Method

    Science.gov (United States)

    Garai, Anirban; Diosady, Laslo T.; Murman, Scott M.; Madavan, Nateri K.

    2016-01-01

    Recent progress towards developing a new computational capability for accurate and efficient high-fidelity direct numerical simulation (DNS) and large-eddy simulation (LES) of turbomachinery is described. This capability is based on an entropy- stable Discontinuous-Galerkin spectral-element approach that extends to arbitrarily high orders of spatial and temporal accuracy, and is implemented in a computationally efficient manner on a modern high performance computer architecture. An inflow turbulence generation procedure based on a linear forcing approach has been incorporated in this framework and DNS conducted to study the effect of inflow turbulence on the suction- side separation bubble in low-pressure turbine (LPT) cascades. The T106 series of airfoil cascades in both lightly (T106A) and highly loaded (T106C) configurations at exit isentropic Reynolds numbers of 60,000 and 80,000, respectively, are considered. The numerical simulations are performed using 8th-order accurate spatial and 4th-order accurate temporal discretization. The changes in separation bubble topology due to elevated inflow turbulence is captured by the present method and the physical mechanisms leading to the changes are explained. The present results are in good agreement with prior numerical simulations but some expected discrepancies with the experimental data for the T106C case are noted and discussed.

  6. Hipertensão venosa episcleral idiopática unilateral em mulher jovem Unilateral idiopathic elevated episcleral venous pressure in a young woman

    Directory of Open Access Journals (Sweden)

    Marcelo Mendes Lavezzo

    2013-02-01

    Full Text Available O objetivo é relatar o caso de uma paciente de 33 anos, que veio ao Pronto Socorro de Oftalmologia apresentando queixa de redução da acuidade visual à esquerda, de caráter insidioso e progressivo, há dois anos. Ao exame oftalmológico, apresentava ingurgitamento dos vasos da conjuntiva bulbar, pressão intraocular muito elevada e nervo óptico com escavação total à esquerda. Foi submetida à campimetria computadorizada 24:2 WW e SITA-SWAP do olho direito, ambas com resultados dentro da normalidade. As tomografias de crânio e órbitas, bem como ultrassonografia com doppler do globo ocular, artérias oftálmicas e veias supraorbitárias não apresentavam anormalidades. Diante disso, aventou-se a hipótese diagnóstica de hipertensão venosa episcleral idiopática, um diagnóstico de exclusão, visto que patologias intracranianas e intraorbitárias haviam sido excluídas. Paciente foi tratada clinicamente com colírios hipotensores, com redução importante da pressão intraocular à esquerda, porém não o suficiente, evoluindo para trabeculectomia.The objective is to report a 33 year old female who came to the emergency room of Ophthalmology complaining of reduced visual acuity on the left eye, in a progressive and insidious way, about two years ago. In the ophthalmological examination, she presented dilated tortuous vessels in her left bulbar conjunctiva, very high intraocular pressure and increased cupping of the optic disc. SITA-SWAP and 24:2 computed perimetry were performed on the right eye, both within normal limits. CT scans of the skull and orbits, and ultrasonography of the eyeball and doppler of the ophthalmic artery and the supra-orbital veins had no abnormalities. Thus, it was suggested the possibility of idiopathic elevated episcleral venous pressure, an exclusion diagnosis, since intra-cranial and intraorbital pathologies were excluded. The patient was treated medically with hypotensive eyedrops, with significant reduction

  7. Feasibility and antihypertensive effect of replacing regular salt with mineral salt -rich in magnesium and potassium- in subjects with mildly elevated blood pressure

    Directory of Open Access Journals (Sweden)

    Sarkkinen Essi S

    2011-09-01

    Full Text Available Abstract Background High salt intake is linked to hypertension whereas a restriction of dietary salt lowers blood pressure (BP. Substituting potassium and/or magnesium salts for sodium chloride (NaCl may enhance the feasibility of salt restriction and lower blood pressure beyond the sodium reduction alone. The aim of this study was to determine the feasibility and effect on blood pressure of replacing NaCl (Regular salt with a novel mineral salt [50% sodium chloride and rich in potassium chloride (25%, magnesium ammonium potassium chloride, hydrate (25%] (Smart Salt. Methods A randomized, double-blind, placebo-controlled study was conducted with an intervention period of 8-weeks in subjects (n = 45 with systolic (SBP 130-159 mmHg and/or diastolic (DBP 85-99 mmHg. During the intervention period, subjects consumed processed foods salted with either NaCl or Smart Salt. The primary endpoint was the change in SBP. Secondary endpoints were changes in DBP, daily urine excretion of sodium (24-h dU-Na, potassium (dU-K and magnesium (dU-Mg. Results 24-h dU-Na decreased significantly in the Smart Salt group (-29.8 mmol; p = 0.012 and remained unchanged in the control group: resulting in a 3.3 g difference in NaCl intake between the groups. Replacement of NaCl with Smart Salt resulted in a significant reduction in SBP over 8 weeks (-7.5 mmHg; p = 0.016. SBP increased (+3.8 mmHg, p = 0.072 slightly in the Regular salt group. The difference in the change of SBP between study groups was significant (p Conclusions The substitution of Smart Salt for Regular salt in subjects with high normal or mildly elevated BP resulted in a significant reduction in their daily sodium intake as well as a reduction in SBP. Trial Registration ISRCTN: ISRCTN01739816

  8. Carbohydrates in thermophile metabolism: calculation of the standard molal thermodynamic properties of aqueous pentoses and hexoses at elevated temperatures and pressures

    Science.gov (United States)

    Amend, Jan P.; Plyasunov, Andrey V.

    2001-11-01

    Experimental thermodynamic data for aqueous organic compounds can be combined with the revised Helgeson-Kirkham-Flowers (HKF) equations of state to generate parameters that can be used to estimate standard molal properties as functions of temperature and pressure. In this study, we regressed thermodynamic data for aqueous carbohydrates at temperatures up to 393 K reported in the literature to permit the calculation of the apparent standard molal Gibbs free energies and enthalpies of formation (ΔGo and ΔHo, respectively) and the standard molal entropies (S2o), heat capacities (CP,2o), and volumes (V2o) to 423 K and several hundred MPa of aqueous C5 aldoses (ribose, arabinose, xylose, lyxose) and C5 ketoses (ribulose, xylulose) as well as C6 aldoses (glucose, mannose, galactose) and C6 ketoses (fructose, sorbose). Values of ΔGo for these 11 aqueous carbohydrates are given as a function of temperature at the saturated water vapor pressure (PSAT) and at 50 MPa. Values of ΔGo for aqueous glucose are then combined with those of other aqueous organic and inorganic compounds to calculate values of the standard molal Gibbs free energies of 13 fermentation and respiration reactions (ΔGro) known or likely to be carried out by thermophilic microorganisms. Finally, values of the overall Gibbs free energies of these reactions (ΔGr) are calculated at the temperature, pressure, and chemical composition that obtain in the hydrothermal fluids of Vulcano Island, southern Italy, a site that is widely known for its tremendous diversity of organisms able to live at high temperatures. At likely activities of aqueous glucose, it is shown that thermophiles in the hot springs of Vulcano at 373 K and ∼0.1 MPa can gain between 400 and 3000 kJ per mole of glucose fermented or respired.

  9. Pressure dependance of the stability limits and NO{sub x} production in the case of elevated swirl flames; Druckabhaengigkeit der Stabilitaetsgrenze und der NO{sub x} Produktion im Fall abgehobener Drallflammen

    Energy Technology Data Exchange (ETDEWEB)

    Kasabov, P.; Zarzalis, N. [Karlsruhe Univ. (Germany)

    2009-07-01

    The authors of the contribution under consideration examine the pressure dependence of the stability limits and NO{sub x} production at elevated swirl flames. Due to a reaction-free premixing process, an elevated homogeneity of the inflammable mixture is attained which positively affects the waste gas emissions. The influences of pressure, air preheating temperature as well as the composition of the mixture on the production of nitrogen oxides and on the lean limits of deletion are investigated. The influence of the Reynolds number and the retention time was analyzed by means of the measurement of differently large, but geometrically similar nozzles. The concentration of oxygen is below 20 ppm regarding to 15 % residual oxygen within the entire range of pressure, and at adiabatic flame temperatures up to 1,800 K.

  10. Review and Response to the Final Report of the National Black Health Providers Task Force on High Blood Pressure Education and Control.

    Science.gov (United States)

    Public Health Service (DHHS), Rockville, MD.

    This report presents the National Heart, Lung, and Blood Institute's (NHLBI) review of and response to the final report of the National Black Health Providers Task Force on High Blood Pressure Education and Control. The response includes a statement of NHLBI's involvement in health research, and descriptions of what steps can be taken to solve the…

  11. Social support buffering of the relation between low income and elevated blood pressure in at-risk African-American adults.

    Science.gov (United States)

    Coulon, S M; Wilson, D K

    2015-10-01

    Socioeconomic disadvantage has been linked to elevated blood pressure (BP), and the purpose of this study was to assess whether interpersonal social supports buffer these adverse relations in African-American adults. In three communities matched demographically, a subsample of participants (N = 204) of the Positive Action for Today's Health trial provided measures of perceived social support, annual household income, and BP. Multiple regression analyses with cross-product interactions were conducted using follow-up data. The sample had a mean age of 52.8 years (SD = 15.1), and was predominantly female (66 %) with a high body mass index (M = 33.5, SD = 14.7). Results indicated an inverse relation between social support and diastolic BP (B = -.178, p = .005), and also an interaction with income (p = .046), such that higher social support related to lower diastolic BP in the lowest-income individuals (B = -1.05). The same direct (B = -.141, p = .025) and interacting (B = -1.42, p = .040) social support effects were present for systolic BP, however the omnibus model for systolic BP was not significant, F(6, 196) = 1.80, p = .09. The hypothesized buffering effect of social support on the adverse relation of income to BP was partially supported in at-risk African-American adults. Future prevention efforts for reducing the impact of socioeconomic stress on BP may aim to increase perceptions of social support.

  12. Fish, Long-Chain n-3 PUFA and Incidence of Elevated Blood Pressure: A Meta-Analysis of Prospective Cohort Studies

    Directory of Open Access Journals (Sweden)

    Bo Yang

    2016-01-01

    Full Text Available Results from prospective cohort studies on fish or long-chain (LC n-3 polyunsaturated fatty acid (PUFA intake and elevated blood pressure (EBP are inconsistent. We aimed to investigate the summary effects. Pertinent studies were identified from PubMed and EMBASE database through October 2015. Multivariate-adjusted risk ratios (RRs for incidence of EBP in the highest verses the bottom category of baseline intake of fish or LC n-3 PUFA were pooled using a random-effects meta-analysis. Over the follow-up ranging from 3 to 20 years, 20,497 EBP events occurred among 56,204 adults from eight prospective cohort studies. The summary RR (SRR was 0.96 (95% CI: 0.81, 1.14; I2 = 44.70% for fish in four studies, and 0.73 (95% CI: 0.60, 0.89; I2 = 75.00% for LC n-3 PUFA in six studies (three studies for biomarker vs. three studies for diet. Circulating LC n-3 PUFA as biomarker was inversely associated with incidence of EBP (SRR: 0.67; 95% CI: 0.55, 0.83, especially docosahexaenoic acid (SRR: 0.64; 95% CI: 0.45, 0.88, whereas no significant association was found for dietary intake (SRR: 0.80; 95% CI: 0.58, 1.10. The present finding suggests that increased intake of docosahexaenoic acid to improve its circulating levels may benefit primary prevention of EBP.

  13. Documentation of probabilistic fracture mechanics codes used for reactor pressure vessels subjected to pressurized thermal shock loading: Parts 1 and 2. Final report

    International Nuclear Information System (INIS)

    Balkey, K.; Witt, F.J.; Bishop, B.A.

    1995-06-01

    Significant attention has been focused on the issue of reactor vessel pressurized thermal shock (PTS) for many years. Pressurized thermal shock transient events are characterized by a rapid cooldown at potentially high pressure levels that could lead to a reactor vessel integrity concern for some pressurized water reactors. As a result of regulatory and industry efforts in the early 1980's, a probabilistic risk assessment methodology has been established to address this concern. Probabilistic fracture mechanics analyses are performed as part of this methodology to determine conditional probability of significant flaw extension for given pressurized thermal shock events. While recent industry efforts are underway to benchmark probabilistic fracture mechanics computer codes that are currently used by the nuclear industry, Part I of this report describes the comparison of two independent computer codes used at the time of the development of the original U.S. Nuclear Regulatory Commission (NRC) pressurized thermal shock rule. The work that was originally performed in 1982 and 1983 to compare the U.S. NRC - VISA and Westinghouse (W) - PFM computer codes has been documented and is provided in Part I of this report. Part II of this report describes the results of more recent industry efforts to benchmark PFM computer codes used by the nuclear industry. This study was conducted as part of the USNRC-EPRI Coordinated Research Program for reviewing the technical basis for pressurized thermal shock (PTS) analyses of the reactor pressure vessel. The work focused on the probabilistic fracture mechanics (PFM) analysis codes and methods used to perform the PTS calculations. An in-depth review of the methodologies was performed to verify the accuracy and adequacy of the various different codes. The review was structured around a series of benchmark sample problems to provide a specific context for discussion and examination of the fracture mechanics methodology

  14. Final Report DE-FG02-00ER54583: 'Physics of Atmospheric Pressure Glow Discharges' and 'Nanoparticle Nucleation and Dynamics in Low-Pressure Plasmas'

    International Nuclear Information System (INIS)

    Kortshagen, Uwe; Heberlein, Joachim; Girshick, Steven L.

    2009-01-01

    This project was funded over two periods of three years each, with an additional year of no-cost extension. Research in the first funding period focused on the physics of uniform atmospheric pressure glow discharges, the second funding period was devoted to the study of the dynamics of nanometer-sized particles in plasmas.

  15. CO{sub 2} exchange environmental productivity indices, and productivity of agaves and cacti under current and elevated atmospheric CO{sub 2} concentrations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Nobel, P.S.

    1994-12-31

    The research described in the proposal investigated net CO{sub 2} uptake and biomass accumulation for an extremely productive CAM plant, the prickly pear cactus Opuntia ficus-indica, under conditions of elevated CO{sub 2} concentrations for relatively long periods. The influences of soil water status, air temperature, and the photosynthetic photon flux (PPF) on net CO{sub 2} uptake over 24-h periods were evaluated to enable predictions to be made based on an Environmental Productivity Index (EPI). Specifically, EPI predicts the fraction of maximal daily net CO{sub 2} uptake based on prevailing environmental conditions. It is the product of indices for temperature, soil water, and intercepted PPF, each of which range from 0.00 when that index factor completely inhibits net CO{sub 2} uptake to 1.00 when no limitation occurs. For instance, the Water Index is 1.00 under wet conditions and decreases to 0.00 during prolonged drought. Although the major emphasis of the research was on net C0{sub 2} uptake and the resulting biomass production for O. ficus-indica, effects of elevated CO{sub 2} concentrations on root: shoot ratios and on the activities of the two carboxylating enzymes were also investigated. Moreover, experiments were also done on other CAM plants, including Agave deserti, Agave salmiana, and Hylocereus undatus, and Stenocereus queretaroensis.

  16. Review of technical issues related to the failure of Rosemount pressure transmitters due to fill oil loss. Final report

    International Nuclear Information System (INIS)

    James, R.W.; Gaertner, J.P.; Burns, E.T.; Horn, A.; Lee, L.K.

    1994-08-01

    Rosemount pressure transmitters are extensively used in both safety and non-safety applications in US nuclear power plants. They are used to measure pressure, flow, and water level. Rosemount pressure transmitter models 1151, 1152, 1153A, 1153, and 1154 use a fill oil to hydraulically transmit process pressure exerted on outer isolating diaphragms to internal diaphragms. The resulting deflection of the internal diaphragms changes the distance between them and a central diaphragm separating the transmitter interior into two volumes. The change in distance is measured as a change in electrical capacitance between the isolating diaphragms and the central diaphragm and can be related to differential pressure. The fill oil also functions as a dielectric. It has been well established that this fill oil can potentially leak over time, decreasing transmitter accuracy and increasing transmitter response time. Ultimately, the transmitter can fail. An extensive effort has been expended by the nuclear power industry collectively to analyze this issue and develop technically sound and reasonable requirements to mitigate the effects of oil loss in Rosemount pressure transmitters. Despite this, technical concerns have still been raised regarding the technical validity of the past analyses of this problem and its scope. In May 1993, the NRC created an internal group to comprehensively review the Rosemount issue and the NRC's action in addressing it to ensure that all available technical information has been considered. Because this issue remains of active technical interest and because the past work on this subject has been done by many different groups and organizations, EPRI has prepared this report to thoroughly document the current technical understanding of this issue, to perform additional analysis, and to identify any appropriate additional technical research activities regarding oil loss in Rosemount pressure transmitters

  17. Crystal-field excitations in PrAl sub 3 and NdAl sub 3 at ambient and elevated pressure

    CERN Document Server

    Straessle, T; Rusz, J; Janssen, S; Juranyi, F; Sadykov, R; Furrer, A

    2003-01-01

    The crystal fields (CFs) of the binary rare-earth compounds PrAl sub 3 and NdAl sub 3 have been examined at ambient pressure by means of inelastic neutron scattering. The CF of the latter compound has also been measured under hydrostatic pressure (p = 0.84 GPa). The observed substantial changes of the CF under pressure are discussed within the framework of first-principles density functional theory calculations.

  18. Magnetically applied pressure-shear : a new technique for direct strength measurement at high pressure (final report for LDRD project 117856).

    Energy Technology Data Exchange (ETDEWEB)

    Lamppa, Derek C.; Haill, Thomas A.; Alexander, C. Scott; Asay, James Russell

    2010-09-01

    A new experimental technique to measure material shear strength at high pressures has been developed for use on magneto-hydrodynamic (MHD) drive pulsed power platforms. By applying an external static magnetic field to the sample region, the MHD drive directly induces a shear stress wave in addition to the usual longitudinal stress wave. Strength is probed by passing this shear wave through a sample material where the transmissible shear stress is limited to the sample strength. The magnitude of the transmitted shear wave is measured via a transverse VISAR system from which the sample strength is determined.

  19. Medical Devices; Obstetrical and Gynecological Devices; Classification of the Pressure Wedge for the Reduction of Cesarean Delivery. Final order.

    Science.gov (United States)

    2017-12-28

    The Food and Drug Administration (FDA or we) is classifying the pressure wedge for the reduction of cesarean delivery into class II (special controls). The special controls that apply to the device type are identified in this order and will be part of the codified language for the pressure wedge for the reduction of cesarean delivery's classification. We are taking this action because we have determined that classifying the device into class II (special controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.

  20. Expert judgment study on wind pressure coefficients. Part 2 : Unprocessed data: Expert rationales Wind tunnel data. Final report

    NARCIS (Netherlands)

    De Wit, S.

    1999-01-01

    In the design of low-rise buildings, wind tunnel experiments are scarcely employed to assess the wind-induced pressures, which are required e.g. for the simulation of ventilation flows or for the evaluation of the structural integrity. Instead, techniques are used, which predominandy rely on inter-

  1. Evaluation of final vapor pressures in the loss of flow accident in an irradiation device of a pool reactor core

    International Nuclear Information System (INIS)

    Verri, A.

    1987-01-01

    The reliability feature, are described for a device containing samples, at a temperatures of 300 grade centigrades, in a reactor core for a long time. After an examination of the maximum accident event, the maximum vapour pressure originated by the inlet of reactor cooling water into the experimental device, is evaluated

  2. Changes in Nafion® 117 internal structure and related properties during exposure to elevated temperature and pressure in an aqueous environment

    Czech Academy of Sciences Publication Activity Database

    Mališ, J.; Paidar, M.; Bystroň, T.; Brožová, Libuše; Zhigunov, Alexander; Bouzek, K.

    2018-01-01

    Roč. 262, 1 February (2018), s. 264-275 ISSN 0013-4686 Institutional support: RVO:61389013 Keywords : Nafion * elevated temperature * excessive swelling Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 4.798, year: 2016

  3. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Loginovskiy, V.I.; Medinger, N.V.; Rasskazov, V.A.; Solonitsyn, V.A.

    1983-01-01

    An elevator is proposed which includes a body, spring loaded cams and a shut-off ring. To increase the reliability of the elevator by eliminating the possibility of spontaneous shifting of the shut-off ring, the latter is equipped with handles hinged to it and is made with evolvent grooves. The cams are equipped with rollers installed in the evolvent grooves of the shut off ring, where the body is made with grooves for the handles.

  4. Critical Heat Flux Phenomena at HighPressure & Low Mass Fluxes: NEUP Final Report Part I: Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States); Wu, Qiao [Oregon State Univ., Corvallis, OR (United States)

    2015-04-30

    This report is a preliminary document presenting an overview of the Critical Heat Flux (CHF) phenomenon, the High Pressure Critical Heat Flux facility (HPCHF), preliminary CHF data acquired, and the future direction of the research. The HPCHF facility has been designed and built to study CHF at high pressure and low mass flux ranges in a rod bundle prototypical of conceptual Small Modular Reactor (SMR) designs. The rod bundle is comprised of four electrically heated rods in a 2x2 square rod bundle with a prototypic chopped-cosine axial power profile and equipped with thermocouples at various axial and circumferential positions embedded in each rod for CHF detection. Experimental test parameters for CHF detection range from pressures of ~80 – 160 bar, mass fluxes of ~400 – 1500 kg/m2s, and inlet water subcooling from ~30 – 70°C. The preliminary data base established will be further extended in the future along with comparisons to existing CHF correlations, models, etc. whose application ranges may be applicable to the conditions of SMRs.

  5. Studies on the effectiveness of measures to maintain the integrity of pressurized components in German nuclear power plants. Final report

    International Nuclear Information System (INIS)

    Elmas, M.; Jendrich, U.; Michel, F.; Reck, H.; Schimpfke, T.; Walter, M.; Wenke, R.

    2013-03-01

    The overall objective of the project was to investigate the effectiveness of measures to maintain the as-built quality of the pressure-retaining components in German nuclear power plants. In particular, investigations were performed on the application of the break preclusion concept, existing monitoring systems and the significance of the pressure test as part of the inspection concept. Moreover, the KompInt knowledge base has been updated. Break preclusion for pipes was applied in all German plants already during planning or after commissioning to a varying extent. The basic features of the required assessments were considered in the German nuclear regulations for the first time by inclusion in the safety requirements for nuclear power plants of 2012. The requirements for assessments, differing in their degree of detail, in the interpretations of these safety requirements and in the safety standard KTA 3206 are still in the draft stage. For the first time, the vessels as well as housings of valves and pumps are also included in the concept. Through the use of advanced monitoring systems it was possible in German plants at an early stage to establish modes of operation that minimise the load on components, to carry out appropriate technical backfitting measures, and to identify damages. In plant areas where local water chemistry parameters may result that deviate from the specification, the effectiveness of water chemistry monitoring is limited. In this case, other operational measures must be taken. The results of the simulations performed with the help of the GRS-developed PROST computer code to determine the significance of pressure tests lead - in accordance with the results of operating experience evaluation - to the conclusion that pressure tests carried out within the pressure-retaining boundary contribute to safeguarding the integrity. The user-friendliness of the KompInt knowledge base has been increased by changing over to a new hardware, a software

  6. Elevator and hydraulics; Elevator to yuatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, I. [Hitachi, Ltd., Tokyo (Japan)

    1994-07-15

    A hydraulic type elevator is installed in relatively lower buildings as compared with a rope type elevator, but the ratio in the number of installation of the former elevator is increasing. This paper explains from its construction and features to especially various control systems for the riding comfort and safety. A direct push-up system with hydraulic jacks arranged beneath a car, and an indirect push-up system that has hydraulic jacks arranged on flank of a car and transmits the movement of a plunger via a rope are available. The latter system eliminates the need of large holes to embed hydraulic jacks. While the speed is controlled by controlling flow rates of high-pressure oil, the speed, position, acceleration and even time differential calculus of the acceleration must be controlled severely. The system uses two-step control for the through-speed and the landing speed. Different systems that have been realized may include compensation for temperatures in flow rate control valves, load pressures, and oil viscosity, from learning control to fuzzy control for psychological effects, or control of inverters in motors. 13 refs., 12 figs., 1 tab.

  7. Monocular Elevation Deficiency - Double Elevator Palsy

    Science.gov (United States)

    ... Español Condiciones Chinese Conditions Monocular Elevation Deficiency/ Double Elevator Palsy En Español Read in Chinese What is monocular elevation deficiency (Double Elevator Palsy)? Monocular Elevation Deficiency, also known by the ...

  8. Laminar burning velocity and Markstein length of nitrogen diluted natural gas/hydrogen/air mixtures at normal, reduced and elevated pressures

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Haiyan [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Eng., Xi' an Jiaotong University (China); Institute of High Performance Computing, A-star (Singapore); Ji, Min; Jiao, Qi; Huang, Qian; Huang, Zuohua [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Eng., Xi' an Jiaotong University (China)

    2009-04-15

    Flame propagation of premixed nitrogen diluted natural gas/hydrogen/air mixtures was studied in a constant volume combustion bomb under various initial pressures. Laminar burning velocities and Markstein lengths were obtained for the diluted stoichiometric fuel/air mixtures with different hydrogen fractions and diluent ratios under various initial pressures. The results showed that both unstretched flame speed and unstretched burning velocity are reduced with the increase in initial pressure (except when the hydrogen fraction is 80%) as well as diluent ratio. The velocity reduction rate due to diluent addition is determined mainly by hydrogen fraction and diluent ratio, and the effect of initial pressure is negligible. Flame stability was studied by analyzing Markstein length. It was found that the increase of initial pressure and hydrogen fraction decreases flame stability and the flame tends to be more stable with the addition of diluent gas. Generally speaking, Markstein length of a fuel with low hydrogen fraction is more sensitive to the change of initial pressure than that of a one with high hydrogen fraction. (author)

  9. Effect of Elevated Intracranial Pressure on Amplitudes and Frequency Tuning of Ocular Vestibular Evoked Myogenic Potentials Elicited by Bone-Conducted Vibration.

    Science.gov (United States)

    Gürkov, Robert; Speierer, Guillaume; Wittwer, Luis; Kalla, Roger

    Recently, it could be demonstrated that an increased intracranial pressure causes a modulation of the air conducted sound evoked ocular vestibular evoked myogenic potential (oVEMP). The mechanism for this modulation is not resolved and may depend on a change of either receptor excitability or sound energy transmission. oVEMPs were elicited in 18 healthy subjects with a minishaker delivering 500 and 1000 Hz tone bursts, in supine and tilted positions. The study could confirm the frequency tuning of oVEMP. However, at neither stimulus frequency could a modulating effect of increased intracranial pressure be observed. These data suggest that the observed modulation of the oVEMP response by an increased intracranial pressure is primarily due to the effect of an increased intralabyrinthine pressure onto the stiffness of the inner ear contents and the middle ear-inner ear junction. Future studies on the effect of intracranial pressure on oVEMP should use air-conducted sound and not bone-conducted vibration.

  10. Damage dosimetry and embrittlement monitoring of nuclear pressure vessels in real time by magnetic properties measurement. Final report

    International Nuclear Information System (INIS)

    Ougouag, A.M.; Stubbins, J.F.; Williams, J.F.; Shong, Wei-Ja.

    1995-04-01

    This program developed a nondestructive technique for gauging the progress of embrittlement of nuclear pressure vessel steels (PVS) by means of monitoring radiation-induced changes in magnetic properties. The technique was developed by running a series of experiments in reactor on typical nuclear pressure vessel steels and weldment material. Following irradiation, changes in magnetic properties were measured and correlated with irradiation dose and with mechanical properties changes, where possible. The changes in magnetic properties were unique to the irradiation environment, and were much larger than those produce by thermal aging in the absence of irradiation. Special techniques for magnetic properties change measurement were developed and complimented by more standard magnetic properties measurement techniques including SQUID measurements. The results of the experiments revealed that magnetic properties were very sensitive to irradiation. Changes in microstructurally-related magnetic properties of as much as 40% were noted after irradiation exposure of as little as 10 17 n/cm 2 (E > 0.1 MeV). The magnetic properties changes plateaued out after doses of around as 10 18 n/cm 2 (E > 0.1 MeV). It is unclear whether further changes would be noted at higher doses which would also be useful for tracking the embrittlement phenomenon. This is recommended for further study. The work supported here resulted in several publications in the open scientific literature

  11. Final air test results for the 1/5-scale Mark I boiling water reactor pressure suppression experiment

    International Nuclear Information System (INIS)

    Collins, E.K.; Lai, W.

    1977-01-01

    A loss-of-coolant accident (LOCA) in a boiling-water reactor (BWR) power plant has never occurred. However, because this type of accident is particularly severe, it is used as a principal basis for design. During a hypothetical LOCA in a Mark I BWR, air followed by steam is injected from a drywell into a toroidal wetwell about half-filled with water. A series of consistent, versatile, and accurate air-water tests simulating LOCA conditions was completed in the Lawrence Livermore Laboratory 1/5-Scale Mark I BWR Pressure Suppression Experimental Facility. Results from this test series were used to quantify the vertical loading function and to study the associated fluid dynamic phenomena. Detailed histories of vertical loads on the wetwell are shown. In particular, variations of hydrodynamic-generated vertical loads with changes in drywell pressurization rate, downcomer submergence, and the vent-line loss coefficient are established. Initial drywell overpressure, which partially preclears the downcomers of water, substantially reduces the peak vertical loads. Scaling relationships, developed from dimensional analysis and verified by bench-top experiments, allow the 1/5-scale results to be applied to a full-scale BWR power plant. This analysis leads to dimensionless groupings which are invariant. These groupongs show that if water is used as the working fluid, the magnitude of the forces in a scaled facility is reduced by the cube of the scale factor; the time when these forces occur is reduced by the square root of the scale factor

  12. The Gly482Ser genotype at the PPARGC1A gene and elevated blood pressure: a meta-analysis involving 13,949 individuals

    DEFF Research Database (Denmark)

    Vimaleswaran, Karani Santhanakrishnan; Luan, Jian'an; Andersen, Gitte

    2008-01-01

    The protein encoded by the PPARGC1A gene is expressed at high levels in metabolically active tissues and is involved in the control of oxidative stress via reactive oxygen species detoxification. Several recent reports suggest that the PPARGC1A Gly482Ser (rs8192678) missense polymorphism may relate...... inversely with blood pressure. We used conventional meta-analysis methods to assess the association between Gly482Ser and systolic (SBP) or diastolic blood pressures (DBP) or hypertension in 13,949 individuals from 17 studies, of which 6,042 were previously unpublished observations. The studies comprised...

  13. Pré-hipertensão arterial e pressão de pulso aumentada em adolescentes: prevalência e fatores associados Arterial prehypertension and elevated pulse pressure in adolescents: prevalence and associated factors

    Directory of Open Access Journals (Sweden)

    Maria Luiza Garcia Rosa

    2006-07-01

    Full Text Available OBJETIVO: Estimar a prevalência de pré-hipertensão e pressão de pulso aumentada em escolares, e verificar associação dessas duas condições com sexo, idade, maturidade sexual, obesidade e atividade física. MÉTODOS: Em amostra de 456 estudantes de 12 a 17 anos, de escolas públicas e privadas do bairro do Fonseca, Niterói-RJ, entre 2003 e 2004, mediu-se a pressão arterial em duas visitas, aplicou-se questionário e foram feitas medidas antropométricas. RESULTADOS: Trinta e nove (8,6% adolescentes apresentaram pré-hipertensão (PH e 13,4%, pressão de pulso (PP aumentada. Na análise bivariada, a PH mostrou associação significativa com sexo, idade e obesidade, com prevalência maior em meninos, naqueles de 15 a 17 anos, e nos obesos. A PP aumentada associou-se somente com o sexo - maior prevalência nos meninos. A maturidade sexual não mostrou associação com a PH ou PP aumentada. Na regressão logística, as associações se mantiveram, com razões de chance de prevalência de PH de 7,7 para sexo; 4,3 para idade e 4,6 para obesidade; e de PP aumentada, de 10,8 para sexo. A PP mostrou correlação positiva com a atividade física. O aumento da PP ocorreu com o aumento da pressão arterial sistólica. CONCLUSÃO: A PH e a PP aumentadas estão presentes em adolescentes em uma população com baixa prevalência de hipertensão, principalmente em meninos, indicando a necessidade de realização de estudos com desenhos prospectivos para examinar a persistência e o impacto dessas condições.OBJECTIVE: To estimate the prevalence of prehypertension and elevated pulse pressure in adolescents and assess the association between those two conditions and sex, age, sexual development, obesity and physical activity. METHODS: Anthropometrical data and blood pressure were measured in and a questionnaire was applied to 456 adolescents (aged 12 to 17 years recruited from public and private schools, in the Fonseca district, in the city of Niter

  14. Pressure-controlled intermittent coronary sinus occlusion (PICSO) in acute ST-segment elevation myocardial infarction: results of the Prepare RAMSES safety and feasibility study

    NARCIS (Netherlands)

    van de Hoef, Tim P.; Nijveldt, Robin; van der Ent, Martin; Neunteufl, Thomas; Meuwissen, Martijn; Khattab, Ahmed; Berger, Rudolf; Kuijt, Wichert J.; Wykrzykowska, Joanna; Tijssen, Jan G. P.; van Rossum, Albert C.; Stone, Gregg W.; Piek, Jan J.

    2015-01-01

    Pressure-controlled intermittent coronary sinus occlusion (PICSO) may improve myocardial perfusion after pPCI. We evaluated the safety and feasibility of PICSO after pPCI for STEMI, and explored its effects on infarct size and myocardial function. Thirty patients were enrolled following successful

  15. Ultrasonic measurements at elevated pressures (9 GPa) to determine Poisson's ratio and other elastic moduli of NaCl and NaF

    International Nuclear Information System (INIS)

    Morris, C.E.; Jamieson, J.C.; Yarger, F.L.

    1976-01-01

    Transit times of longitudinal and transverse ultrasonic waves were measured simultaneously in NaCl and NaF as a function of ''quasihydrostatic'' pressure to 9 GPa. The dimensionless ratio of these transit times yields directly the ratio of the longitudinal to shear velocity. This velocity ratio is independent of sample length. Using third-order elasticity theory a correction for a probable superimposed uniaxial stress component may be made. When done, this allows the direct determination of Poisson's ratio for each pressure. Shock-wave data are used to obtain other elastic moduli and velocities of shear and longitudinal waves. Apparatus for making these measurements is described and data for NaCl and NaF are presented

  16. Thermodynamic study of Eu3+/Eu2+ redox reaction in aqueous solutions at elevated temperatures and pressures by means of cyclic voltametry

    International Nuclear Information System (INIS)

    Bilal, B.A.

    1991-01-01

    The redox potential of the couple Eu 3+ /E 2+ in aqueous NaCl, NaClO 4 and Na 2 SO 4 solutions of different strength and various pH values has been determined by means of cyclic voltammetry up to 458 K and 1 kbar. In all cases reversible voltammograms were obtained. Compared to the redox potential in ClO 4 - solutions of pH 2, no significant shift was observed in Cl-solutions of the same pH, whereas a drastic shift to more negative potentials in solutions of SO 4 2- and in Cl - solutions of higher pH (pH 3-5) was obtained. This indicates a negligible complexation of Eu 3+ by means of Cl - but a strong one by means of OH - and SO 4 2- . An isothermal pressure increase up to 1 kbar led to a shift of only few mV more negative, indicating a small pressure dependence of the change of the partial molar volume (ΔV el ) accompanying the redox reaction, which results in this case only due to the different degrees of electrostriction. A more drastic shift of the redox potential (in the positive direction) results with increasing temperature. The isobaric temperature dependence of the redox potential is described by a two parameter equation which remains valid up to the saturation pressure at 458 K, due to the small pressure effect. ΔS and ΔH of the redox reaction has been determined. (orig.)

  17. Trial occlusion to assess the risk of persistent pulmonary arterial hypertension after closure of a large patent ductus arteriosus in adolescents and adults with elevated pulmonary artery pressure.

    Science.gov (United States)

    Zhang, Duan-Zhen; Zhu, Xian-Yang; Lv, Bei; Cui, Chun-Sheng; Han, Xiu-Min; Sheng, Xiao-Tang; Wang, Qi-Guang; Zhang, Po

    2014-08-01

    No method is available to predict whether patients with patent ductus arteriosus (PDA) and severe pulmonary arterial hypertension (PAH) will show persistent postprocedural PAH (PP-PAH) after PDA closure. This study evaluated the usefulness of trial occlusion for predicting PP-PAH after transcatheter PDA closure in patients with severe PAH. Trial occlusion was performed in 137 patients (age ≥12 years) with PDA and severe PAH. All patients undergoing trial occlusion had a mean pulmonary artery pressure ≥45 mm Hg, pulmonary:systemic flow (Qp/Qs) ratio >1.5, and pulmonary:systemic resistance (Rp/Rs) ratio closure. Linear correlation analysis revealed weak or moderate relationships between the baseline and post-trial pulmonary artery pressures and pulmonary:systemic pressure (Pp/Ps) ratios. Patients were followed up for 1 to 10 years (median: 5 years). PP-PAH (systolic pulmonary artery pressure >50 mm Hg by Doppler echocardiography) was detected in 17 patients (13%), who displayed no significant differences in sex and age compared with patients without PP-PAH. According to discriminant analysis, the strongest discriminators between patients with and without PP-PAH were the baseline left ventricular end-diastolic volume and the baseline and post-trial systolic Pp/Ps ratios. In particular, a post-trial systolic Pp/Ps ratio >0.5 correctly classified 100% of the PP-PAH and non-PAH patients. Trial occlusion is a feasible method to predict PP-PAH in patients with PDA and severe PAH. A post-trial systolic Pp/Ps ratio >0.5 indicates a high risk of PP-PAH occurrence after device closure. © 2014 American Heart Association, Inc.

  18. Densities and apparent molar volumes of HClO4(aq) and Yb(ClO4)3(aq) at elevated temperatures and pressures

    International Nuclear Information System (INIS)

    Hakin, Andrew W.; Lukacs, Michael J.; Jin Lianliu

    2004-01-01

    Relative densities have been measured for acidified aqueous solutions of ytterbium perchlorate {Yb(ClO 4 ) 3 } at approximately T=(348.15, 373.15, 398.15, and 423.15) K and p=(10.0, 20.0, and 30.0) MPa over the concentration range 0.01624≤m 2 /(mol · kg -1 ) ≤ 0.2531 using an optically coupled vibrating tube densimeter (OCVTD). Experimental apparent molar volumes have been calculated from the density measurements, and apparent molar volumes for the aqueous perchlorate salt have been calculated using Young's rule. The application of Young's rule requires apparent molar volumes for aqueous perchloric acid (HClO 4 ) solutions over extended temperature and pressure ranges. These values were calculated from densities for aqueous HClO 4 solutions that were measured using the OCVTD at the same temperatures and pressures as those used to investigate the density surface of the acidified aqueous Yb(ClO 4 ) 3 solutions. The temperature, pressure, and composition surfaces of the apparent molar volumes for Yb(ClO 4 ) 3 (aq) and HClO 4 (aq) have been modelled using Pitzer ion-interaction equations. Apparent molar volumes at infinite dilution obtained from these models have been compared to those which can be calculated using the semi-empirical Helgeson, Kirkham, and Flowers equations of state. Values for the apparent molar volume at infinite dilution of the ytterbium trivalent cation have also been calculated using simple additivity principles

  19. Elevator wheel

    Energy Technology Data Exchange (ETDEWEB)

    Zhornik, V.I.; Cherkov, Ye.M.; Simonov, A.A.

    1982-01-01

    An elevator wheel is suggested for unloading a sunken product from a bath of a heavy-average separator including discs of a bucket with inner walls, and covering sheets hinged to the buckets. In order to improve the degree of dehydration of the removed product, the inner wall of each bucket is made of sheets installed in steps with gaps of one in relation to the other.

  20. 75 FR 22699 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-04-30

    ... La Vista. At South 168th Street.... +1100 Approximately 300 feet +1177 upstream of South 204th Street.... upstream of the Sarpy County, City of La confluence with South Vista, City of Papillion Creek. Papillion... Creek (with levees)..... Just downstream of South +999 City of Bellevue, City of 48th Street. La Vista...

  1. 75 FR 52868 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-08-30

    ... Highway. Turkey Creek Approximately 0.7 mile +565 City of Center Point, downstream of Old City of Clay... inspection at 6757 Old Springville Road, Pinson, AL 35126. City of Homewood Maps are available for inspection.... downstream of South Lone Tree Road. Approximately 1,800 feet +6,949 upstream of Lake Mary Road. Peak View...

  2. 78 FR 45877 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-07-30

    .... Approximately 0.23 mile [caret] 31 upstream of Egan Drive. Lemon Creek Approximately 0.27 mile [caret] 23 City... American Vertical Datum. Depth in feet above ground. [caret] Mean Lower Low Water. ADDRESSES City and...

  3. 76 FR 79098 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-12-21

    ... of North Eagle Drive. Oak Creek Just upstream of the +5253 Town of Rockvale, Town of unnamed railroad... Channel....... At the confluence with +1758 City of Abilene. Cat Claw Creek. Just upstream of Nonesuch...

  4. 77 FR 49367 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-08-16

    ... within the scope of the Regulatory Flexibility Act, 5 U.S.C. 601- 612, a regulatory flexibility analysis... shoreline......... +67 Unincorporated Areas of Polk County. London Creek Watershed Unnamed Pond-- Entire shoreline......... +70 Unincorporated Areas of ICPR Node 28A1. Polk County. London Creek Watershed Unnamed...

  5. 77 FR 49360 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-08-16

    ... confluence. Casey Branch (backwater effects from From the Dale Hollow Lake +663 Unincorporated Areas of Dale Hollow Lake). confluence to Cumberland County. approximately 0.5 mile upstream of the Dale Hollow Lake.... Dale Hollow Lake (Obey River) Entire shoreline within +663 Unincorporated Areas of community...

  6. 75 FR 77762 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-12-14

    .... approximately 1.1 mile upstream of the confluence with Green River Lake. Snake Creek (backwater effects from... Mason Road. Pine Run Approximately 400 feet +752 City of Mason. downstream of Kings Mill Road...

  7. 77 FR 76420 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-12-28

    ... Road. Salt Lick Branch (backwater effects At the Licking River +924 Unincorporated Areas from Licking... +3206 At the intersection of Slide Road and 58th Street......... +3256 * National Geodetic Vertical...). confluence. of Magoffin County. Approximately 355 feet +901 upstream of Clyde Holliday Cemetery Road. [[Page...

  8. 75 FR 18091 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-04-09

    ... Areas Docket No.: FEMA-B-1032 Salt Branch Intersection of Unnamed +163 Unincorporated Areas of Road and... Huntsville. upstream of Green Cove Road. Approximately 75 feet +682 downstream of Drake Avenue. * National.... Approximately 180 feet +575 downstream of Hester Cut Road. Heartsill Creek Tributary 1 At the confluence with...

  9. 76 FR 3531 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-01-20

    ... proof Flood Insurance Study and FIRM available at the address cited below for each community. The BFEs... (All Jurisdictions) Docket No.: FEMA-B-1085 Duck Lake Entire shoreline within +930 Township of Clarence...

  10. 75 FR 34381 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-06-17

    .... Interested lessees and owners of real property are encouraged to review the proof Flood Insurance Study and... Incorporated Areas Docket No.: FEMA-B-1035 Duck Creek At the mouth of the +891 City of Warren. Mahoning River...

  11. 77 FR 3625 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-01-25

    ... encouraged to review the proof Flood Insurance Study and FIRM available at the address cited below for each... Duck Pond Unincorporated Areas of Road (at Junction Hernando County. 1NP0170). Approximately 100 feet...

  12. 77 FR 30220 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-05-22

    ... proof Flood Insurance Study and FIRM available at the address cited below for each community. The BFEs... Areas of 175. Kaufman County. Approximately 1 mile +342 downstream of State Highway 274. Duck Creek...

  13. 76 FR 21664 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-04-18

    ... proof Flood Insurance Study and FIRM available at the address cited below for each community. The BFEs... 2,100 feet +861 upstream of 11th Street. Big Duck Creek At South P Street........ +843 City of...

  14. 76 FR 72627 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-11-25

    ... addresses are listed in the table below. FOR FURTHER INFORMATION CONTACT: Luis Rodriguez, Chief, Engineering.... Paul, Unincorporated Areas of Dakota County. Approximately 10,200 feet +714 upstream of I-35. Mud Creek..., Rosemount, MN 55068. [[Page 72634

  15. 76 FR 35111 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-06-16

    ... addresses are listed in the table below. FOR FURTHER INFORMATION CONTACT: Luis Rodriguez, Chief, Engineering... downstream of Saint Paul of Blackstone, Town of Street. Grafton, Town of Millbury, Town of Millville, Town of... Blackstone Maps are available for inspection at the Town Hall, 15 Saint Paul Street, Blackstone, MA 01504...

  16. 75 FR 59989 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-09-29

    ... Road. Caracol Creek Approximately 600 feet +770 City of San Antonio. upstream of the confluence with... Stage Road. Leon Creek Tributary M Approximately 1,300 feet +1,202 City of San Antonio. downstream of... Northwest Loop 1604. Unnamed Tributary 5 to Caracol......... Approximately 900 feet +828 City of San Antonio...

  17. 76 FR 8906 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-02-16

    ...-B-1014 Sugar Creek Approximately 2,000 feet +469 Town of West Terre Haute, downstream of Conrail... Approximately 1,214 feet +470 Town of West Terre Haute, upstream of I-70. Unincorporated Areas of Vigo County... West Terre Haute Maps are available for inspection at the Town Hall, 500 National Avenue, West Terre...

  18. 78 FR 48813 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-08-12

    ... Road. Approximately 1.16 miles +292 upstream of Giffords Church Road. Poentic Kill At the Mohawk River... mile upstream of Johnson Cemetery Road. Big Reedy Creek (Backwater effects from From the confluence.... approximately 935 feet upstream of Penrod Road. Deerlick Creek Tributary 6 (Backwater From the confluence with...

  19. 75 FR 3171 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-01-20

    ... Executive Order 12866 of September 30, 1993, Regulatory Planning and Review, 58 FR 51735. Executive Order... Street, Baldwyn, MS 38824. City of Tupelo Maps are available for inspection at the Planning Department... Maps are available for inspection at City Hall, 120 Miner Avenue West, Ladysmith, WI 54848...

  20. 76 FR 54134 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-08-31

    ... under the criteria of section 3(f) of Executive Order 12866 of September 30, 1993, Regulatory Planning... Unincorporated Areas of Pacific Railroad. Park County. Approximately 4.14 miles +4953 downstream of Tom Miner...

  1. 75 FR 23595 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-05-04

    ... 72482. Mesa County, Colorado, and Incorporated Areas Docket No.: FEMA-B-1049 Gold Star Canyon Just above... Middlesex Maps are available for inspection at 1200 Mountain Avenue, Middlesex, NJ 08846. City of New... Indian upstream of the southern Reservation (Turtle corporate limit of Mountain Band). Belcourt...

  2. 75 FR 44155 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-07-28

    .... Approximately 1,400 feet +7776 upstream of West Grimes Creek Road. Junction Creek At Pleasant Drive in Durango.... Unincorporated Areas of La Plata County Maps are available for inspection at 1060 East 2nd Avenue, Durango, CO.... Pepin County. Approximately 6,000 feet +717 upstream of the confluence with Bear Creek. Mississippi...

  3. 77 FR 26959 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-05-08

    ... River At the Mississippi County +335 Unincorporated Areas of boundary. Scott County. At the Alexander... 75110. Preston County, West Virginia, and Incorporated Areas Docket No.: FEMA-B-1166 Back Run At the...

  4. 77 FR 46972 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-08-07

    ... Division, 2400 Broadway Southeast, Albuquerque, NM 87102. Le Flore County, Oklahoma, and Incorporated Areas.... Unincorporated Areas of Le Flore County. At the downstream side of +490 U.S. Route 59. Caston Creek Approximately.... Areas of Le Flore County. Approximately 500 feet +470 upstream of the confluence with Mountain Creek...

  5. 75 FR 23608 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-05-04

    ... Potter County. 287 and South Parsley Road. Playa Lake 6 Approximately 1,000 feet +3624 City of Amarillo... feet +3596 City of Amarillo, northeast of the Unincorporated Areas of intersection of Parsley Potter... County. intersection of Highway 287 and South Parsley Road. Playa Lake 4 At the intersection of +3699...

  6. 77 FR 73324 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-12-10

    ..., Tulip Avenue to the south, and Apricot Avenue to the west. Ponding Area Area bound by East +51... south, and Balsam Street to the west. Ponding Area Area bound by East Thyme +51 Unincorporated Areas of... Street to the west. Ponding Area Area bound by Verano +51 Unincorporated Areas of Drive to the north...

  7. 77 FR 49373 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-08-16

    ... under the criteria of section 3(f) of Executive Order 12866 of September 30, 1993, Regulatory Planning... with +829 Unincorporated Areas of Taylor Fork). Taylor Fork to Madison County. approximately 1,950 feet upstream of the confluence with Taylor Fork. Otter Creek Approximately 0.7 mile +800 City of Richmond...

  8. 76 FR 39011 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-07-05

    ... Dam No. 11. Approximately 7.4 miles + 625 Village of Bagley. upstream of Lock and Dam No. 10... Jefferson Street, Lancaster, WI 53813. Village of Bagley Maps are available for inspection at 400 South Jackley Lane, Bagley, WI 53801. Village of Potosi Maps are available for inspection at 105 North Main...

  9. 77 FR 76929 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-12-31

    ... Rocky Shelby County. Hollow Lane. Approximately 416 feet +464 upstream of Rocky Hollow Lane. Ivy Branch... of County Road 280 (Old Highway 280). Lee Branch Approximately 884 feet +553 City of Birmingham, City... +608 upstream of Hugh Daniel Drive. Lee Brook At the upstream side of +417 City of Helena. County Road...

  10. 78 FR 10072 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-02-13

    ... River. Approximately 250 feet +12 upstream of Grace Terrace. Cedar Swamp Creek At the confluence with +9.... Ninemile Creek. Approximately 1,600 feet +14 upstream of Old Kings Road. Ninemile Creek Tributary 2 At the.... Approximately 2,100 feet +22 upstream of Old Kings Road. North Fork Sixmile Creek At the confluence with +20...

  11. 76 FR 35119 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-06-16

    ... inspection at 301 King Street, Alexandria, VA 22314. Town of Ennis, Montana Docket No.: FEMA-B-1083 Montana... downstream of Grace Avenue. Lancaster County. Approximately 1.0 mile +433 downstream of Old Lansford Road...

  12. 76 FR 39305 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-07-06

    ... Town of Middlebury, upstream of the Unincorporated Areas of confluence with the Elkhart County. Little... Ditch At the confluence with +810 Town of Wakarusa, Baugo Creek. Unincorporated Areas of Elkhart County... 52601. Iowa County, Iowa, and Incorporated Areas Docket No.: FEMA-B-1089 Old Mans Creek Approximately 1...

  13. 76 FR 76055 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-12-06

    ... from the requirements of 44 CFR part 10, Environmental Consideration. An environmental impact... Whiting Main Beaver Dam Ditch Just downstream of +684 Town of Merrillville. Broadway. Approximately 1,000... downstream of 91st +689 Avenue. Main Beaver Dam Ditch Approximately 730 feet +690 Town of Schererville west...

  14. 75 FR 19895 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-04-16

    ... CFR part 10, Environmental Consideration. An environmental impact assessment has not been prepared... Areas Docket No.: FEMA-B-1032 Beaver Dam Lake Entire shoreline +874 City of Beaver Dam, City of Fox Lake, Unincorporated Areas of Dodge County. Beaver Dam River Approximately 377 feet +841 City of Beaver Dam, downstream...

  15. 77 FR 76916 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-12-31

    ... from the requirements of 44 CFR part 10, Environmental Consideration. An environmental impact... upstream of State Route 166. Beaver Creek At the Sweetwater Creek +871 Unincorporated Areas of confluence. Douglas County. Approximately 500 feet +1006 upstream of Patty Court. Beaver Creek Tributary A At the...

  16. 78 FR 36099 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-06-17

    ... within the scope of the Regulatory Flexibility Act, 5 U.S.C. 601- 612, a regulatory flexibility analysis... Surprise, the Central Arizona Unincorporated Areas of Project Canal. Maricopa County. Stage Coach Pass Wash...

  17. 78 FR 5738 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-01-28

    ... newspapers of local circulation and ninety (90) days have elapsed since that publication. The Deputy... Town of Moultonborough, confluence. Town of Sandwich. Approximately 1.70 miles +587 upstream of School... for inspection at the Town Hall, 68 School Street, Effingham, NH 03882. Town of Hart's Location Maps...

  18. 75 FR 68714 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-11-09

    ... available for inspection at 6622 Wilson Mills Road, Mayfield, OH 44143. Village of Moreland Hills Maps are available for inspection at 4350 S.O.M. Center Road, Moreland Hills, OH 44022. Kent County, Rhode Island... Village of Moreland upstream of Woodland Hills. Road. Approximately 1,200 feet +789 upstream of Woodland...

  19. 77 FR 26968 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-05-08

    ... upstream of Port-Hudson Pride Road. Sheet flow between McCarroll Drive and At North Jefferson Place 1 City.... Road. Approximately 0.9 mile +335 upstream of Wagener Trail Road. Dry Branch At the Hollow Creek West +217 Unincorporated Areas of confluence. Aiken County. Approximately 1,200 feet +318 upstream of Dry...

  20. 77 FR 71702 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-12-04

    .... Antores confluence. Approximately 1,000 feet +6802 upstream of Rodeo Road. Arroyo De La Piedra... Piedra confluence. Approximately 600 feet +7320 upstream of Camino Encantado. Arroyo Saiz At the upstream.... Approximately 0.3 mile +7780 upstream of La Entrada. East Arroyo De La Piedra At the Arroyo De La +7199 City of...

  1. 77 FR 21476 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-04-10

    ... State Highway 115. Black River Approximately 9,000 feet +268 City of Pocahontas, downstream of the... the confluence with +269 City of Pocahontas, the Black River. Unincorporated Areas of Randolph County...). Swan Creek At the confluence with +69 City of Lambertville. the Delaware River. Approximately 40 feet...

  2. 76 FR 69665 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-11-09

    .... Alpena County, Michigan (All Jurisdictions) Docket No.: FEMA-B-1151 Lake Huron From approximately 1.3 + 583 City of Alpena, Township miles northwest of the of Alpena. intersection of Rockport Road and Old... Road and Brousseau Road. [[Page 69669

  3. 76 FR 36373 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-06-22

    ... confluence with Cedar Oglesby, City of Ottawa, Creek. City of Peru, Unincorporated Areas of La Salle County..., Ottawa, IL 61350. City of Peru Maps are available for inspection at City Hall, 1727 4th Street, Peru, IL... available for inspection at 220 Clay Street, Cedar Falls, IA 50613. City of Dunkerton [[Page 36379

  4. 75 FR 11468 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-03-11

    ... feet +44 upstream of Wolf Ridge Road. Gum Tree Branch Approximately 100 feet +25 City of Prichard... Approximately 2,600 feet +153 Unincorporated Areas of upstream of Snow Road. Mobile County. Approximately 12,420 feet +183 upstream of Snow Road. Unnamed Branch Approximately 100 feet +88 City of Prichard. downstream...

  5. 77 FR 21485 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-04-10

    ..., Milwaukee, St. Paul and Pacific Railroad. Clear Creek At the confluence with + 1180 City of Clear Lake... City of Mason City, upstream of Chicago, Unincorporated Areas of Milwaukee, St. Paul and Cerro Gordo... at the Chariton County Courthouse, 306 South Cherry Street, Keytesville, MO 65261. Village of Dalton...

  6. 76 FR 50920 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-08-17

    ... Butternut Lake Entire shoreline......... + 1216 Unincorporated Areas of Polk County, Village of Luck. Clam............ + 1210 Unincorporated Areas of Polk County, Village of Luck. Sand Lake Entire shoreline......... + 1124... Village Hall, 404 Main Street, Balsam Lake, WI 54810. Village of Luck Maps are available for inspection at...

  7. 76 FR 43923 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-07-22

    ... Approximately 30 feet downstream of I-64 +22 *National Geodetic Vertical Datum. +North American Vertical Datum... Center Street. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above... +864 upstream of Wallace Street. Moon and Hamilton County Drain......... At the Detention Area F +861...

  8. 76 FR 76060 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-12-06

    ... Illinois Route 34. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above... Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level..., Michigan (All Jurisdictions) Docket No.: FEMA-B-1089 Alward Drain At the confluence with +615 Charter...

  9. 77 FR 45262 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-07-31

    ..., 450 Bastion Road, Halifax, PA 17032. Township of Lower Paxton Maps are available for inspection at the... downstream side of +609 Borough of Tunkhannock, the railroad bridge. Township of Tunkhannock. Approximately 0.7 mile +655 upstream of Bridge Street. Tributary No. 1 to Swale Brook......... At the Swale Brook...

  10. 75 FR 23600 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-05-04

    ... feet +571 upstream of the confluence with Millers Creek. Dale Hollow Lake (Wolf River) At the... upstream of the confluence with Spring Creek. Lake Cumberland Just upstream of the Wolf +760 Unincorporated...

  11. 75 FR 8814 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-02-26

    ... Approximately 118 feet +190 City of Hattiesburg. downstream of Spring Hill Drive. Approximately 1,460 feet +208... 1.280 mile upstream of Hollow Road. Approximately 1.288 mile +1204 upstream of Hollow Road. Tully...

  12. 77 FR 66555 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-11-06

    ... Jefferson City. confluence. Approximately 80 feet +606 upstream of Mesa Avenue. Frog Hollow Tributary At the... the confluence with Newport Creek. Spring Run Approximately 110 feet +576 Borough of Ashley. upstream...

  13. 78 FR 6745 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-01-31

    ...,250 feet +635 upstream of Spring Mountain Lane. Cranberry Creek at Paradise At the upstream side of +715 Township of Paradise. Browns Hill Road. Approximately 200 feet +1092 upstream of Snowbird Lane..., Schoonover Municipal Building, 25 Municipal Drive, East Stroudsburg, PA 18301. Township of Paradise Maps are...

  14. 77 FR 46980 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-08-07

    ... Executive Order 12988. List of Subjects in 44 CFR Part 67 Administrative practice and procedure, Flood... upstream of Northeast 152nd Avenue. Whipple Creek Just downstream of +28 Unincorporated Areas of Northwest...

  15. 75 FR 78617 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-12-16

    .... Rockport Creek Approximately 2,300 feet +260 Unincorporated Areas of downstream of Martin Hot Spring County. Luther King Boulevard. Approximately 1,300 feet +263 downstream of Martin Luther King Boulevard. Town...

  16. 76 FR 10253 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-02-24

    ... Martin Luther King Jr. Boulevard, Room 310, Evansville, IN 47708. Marion County, Kansas, and Incorporated... at the Evansville Civic Center Complex, Building Commission Department, 1 Northwest Martin Luther King Jr. Boulevard, Room 310, Evansville, IN 47708. Unincorporated Areas of Vanderburgh County Maps are...

  17. 77 FR 66737 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-11-07

    ... confluence. Williamsburg County. Approximately 0.9 mile +33 upstream of Hemingway Highway. Boggy Swamp B... Town of Hemingway, confluence. Unincorporated Areas of Williamsburg County. Approximately 0.3 mile +50... Unincorporated Areas of confluence. Williamsburg County. Approximately 1.3 miles +35 upstream of Hemingway...

  18. 75 FR 14091 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-03-24

    ... approximately 0.65 mile Rock Island County, City upstream of the Mercer/ of East Moline, City of Rock Island county Moline, City of Rock boundary and 1.7 mile Island, Village of downstream of the Andalusia, Village... Byron, Village of Rapids City. The Whitside/Rock Island + 588 county boundary (River Mile 512.25...

  19. 75 FR 59634 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-09-28

    ... Courthouse, 100 East Springfield Street, Virginia, IL 62691. Adams County, Indiana, and Incorporated Areas... Unnamed Stream off of Turkey Creek..... At the confluence with +329 City of Henderson. Turkey Creek.... ADDRESSES City of Henderson Maps are available for inspection at City Hall, 400 West Main Street, Henderson...

  20. 77 FR 19112 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-03-30

    ... Township of Lima, River. Township of Scio, Township of Webster, Village of Dexter. Just upstream of North... Webster Maps are available for inspection at 5665 Webster Church Road, Dexter, MI 48130. Village of Barton... Dexter Maps are available for inspection at 6880 Dexter-Pinckney Road, Dexter, MI 48130. Meeker County...

  1. 77 FR 41323 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-07-13

    ... upstream of Westbrook Loop. Shaw Creek-Wide Hollow Creek Walmart At the Wide Hollow Creek +1151 City of...-Wide Hollow Creek Walmart At the Wide Hollow Creek +1149 City of Yakima. Overflow 2. confluence...

  2. 76 FR 29656 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-05-23

    ..., Unincorporated Areas of Canyon County. Just upstream of Lone +2450 Tree Lane/Ustick Road. Renshaw Canal Just... with +632 Unincorporated Areas of Kentucky River). Cow Creek to Estill County. approximately 0.7 mile... of Clearcreek Road. Cow Creek (backwater effects from From the confluence with +632 Unincorporated...

  3. 78 FR 9831 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-02-12

    ... downstream of Nahunta Greene County. Road. Approximately 0.4 mile +75 upstream of Apple Tree Road. Bear Creek... upstream of Beaman Old Creek Road. Cow Branch At the Nahunta Swamp +60 Unincorporated Areas of confluence. Greene County. Approximately 2.1 miles +114 upstream of Cow Branch Road. [[Page 9839

  4. Measurements of laminar burning velocities and flame stability analysis for dissociated methanol-air-diluent mixtures at elevated temperatures and pressures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xuan; Huang, Zuohua; Zhang, Zhiyuan; Zheng, Jianjun; Yu, Wu; Jiang, Deming [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2009-06-15

    The laminar burning velocities and Markstein lengths for the dissociated methanol-air-diluent mixtures were measured at different equivalence ratios, initial temperatures and pressures, diluents (N{sub 2} and CO{sub 2}) and dilution ratios by using the spherically outward expanding flame. The influences of these parameters on the laminar burning velocity and Markstein length were analyzed. The results show that the laminar burning velocity of dissociated methanol-air mixture increases with an increase in initial temperature and decreases with an increase in initial pressure. The peak laminar burning velocity occurs at equivalence ratio of 1.8. The Markstein length decreases with an increase in initial temperature and initial pressure. Cellular flame structures are presented at early flame propagation stage with the decrease of equivalence ratio or dilution ratio. The transition positions can be observed in the curve of flame propagation speed to stretch rate, indicating the occurrence of cellular structure at flame fronts. Mixture diluents (N{sub 2} and CO{sub 2}) will decrease the laminar burning velocities of mixtures and increase the sensitivity of flame front to flame stretch rate. Markstein length increases with an increase in dilution ratio except for very lean mixture (equivalence ratio less than 0.8). CO{sub 2} dilution has a greater impact on laminar flame speed and flame front stability compared to N{sub 2}. It is also demonstrated that the normalized unstretched laminar burning velocity is only related to dilution ratio and is not influenced by equivalence ratio. (author)

  5. Densities and apparent molar volumes of HClO{sub 4}(aq) and Yb(ClO{sub 4}){sub 3}(aq) at elevated temperatures and pressures

    Energy Technology Data Exchange (ETDEWEB)

    Hakin, Andrew W. E-mail: hakin@uleth.ca; Lukacs, Michael J.; Jin Lianliu

    2004-09-01

    Relative densities have been measured for acidified aqueous solutions of ytterbium perchlorate {l_brace}Yb(ClO{sub 4}){sub 3}{r_brace} at approximately T=(348.15, 373.15, 398.15, and 423.15) K and p=(10.0, 20.0, and 30.0) MPa over the concentration range 0.01624{<=}m{sub 2}/(mol {center_dot} kg{sup -1}) {<=} 0.2531 using an optically coupled vibrating tube densimeter (OCVTD). Experimental apparent molar volumes have been calculated from the density measurements, and apparent molar volumes for the aqueous perchlorate salt have been calculated using Young's rule. The application of Young's rule requires apparent molar volumes for aqueous perchloric acid (HClO{sub 4}) solutions over extended temperature and pressure ranges. These values were calculated from densities for aqueous HClO{sub 4} solutions that were measured using the OCVTD at the same temperatures and pressures as those used to investigate the density surface of the acidified aqueous Yb(ClO{sub 4}){sub 3} solutions. The temperature, pressure, and composition surfaces of the apparent molar volumes for Yb(ClO{sub 4}){sub 3}(aq) and HClO{sub 4}(aq) have been modelled using Pitzer ion-interaction equations. Apparent molar volumes at infinite dilution obtained from these models have been compared to those which can be calculated using the semi-empirical Helgeson, Kirkham, and Flowers equations of state. Values for the apparent molar volume at infinite dilution of the ytterbium trivalent cation have also been calculated using simple additivity principles.

  6. Evidence of elevated pressure and temperature during burial of the Salem Limestone in south-central Indiana, USA, and its implications for surprisingly deep burial

    Science.gov (United States)

    Ambers, Clifford P.

    2001-09-01

    A minor, normal fault related to compaction of the grainstone shoal facies of the Salem Limestone in south-central Indiana provides an unusual opportunity to test the pressure and temperature of both faulting and associated stylolitization. Syn-deformational sphalerite occurs in voids along the fault where it intersects an organic-rich shale parting in the sand flat facies overlying the grainstone. The sphalerite contains fluid inclusions that can be used for microthermobaric measurements. Most fluid inclusions in the sphalerite are demonstrably cogenetic with the host sphalerite and of the two-phase aqueous type common in Indiana, although many contain petroleum and others contain gas. Crushing tests in kerosene indicate that the aqueous inclusions contain dissolved methane in varying amounts as high as 1000 ppm. Microthermometry shows that late sphalerite growth, late fault movement, and late stylolitization all occurred as conditions approached 108°C and 292 bars. This pressure is in accord with a normal, basinal, geothermal gradient of 32.5°C/km that would produce the observed temperature under hydrostatic conditions at a burial depth of 2.7 km using an average fluid density of 1.1 g/cm 3. These results serve as a reminder that fluid inclusions in diagenetic minerals hold important temperature and pressure information regarding burial diagenesis of Paleozoic rocks across the North American midcontinent. Detailed study of dissolved gases in fluids trapped in disseminated sphalerite that is common across the midcontinent could help resolve the enigma of sedimentary rocks with high thermal maturity exposed at the surface across the region.

  7. Homogenization Experiments of Crystal-Rich Inclusions in Spodumene from Jiajika Lithium Deposit, China, under Elevated External Pressures in a Hydrothermal Diamond-Anvil Cell

    Directory of Open Access Journals (Sweden)

    Jiankang Li

    2017-01-01

    Full Text Available Extensive studies of the crystal-rich inclusions (CIs hosted in minerals in pegmatite have resulted in substantially different models for the formation mechanism of the pegmatite. In order to evaluate these previously proposed formation mechanisms, the total homogenization processes of CIs hosted in spodumene from the Jiajika pegmatite deposit in Sichuan, China, were observed in situ under external H2O pressures in a new type of hydrothermal diamond-anvil cell (HDAC. The CIs in a spodumene chip were loaded in the sample chamber of HDAC with water, such that the CIs were under preset external H2O pressures during heating to avoid possible decrepitation. Our in situ observations showed that the crystals within the CIs were dissolved in carbonic-rich aqueous fluid during heating and that cristobalite was usually the first mineral being dissolved, followed by zabuyelite and silicate minerals until their total dissolution at temperatures between 500 and 720°C. These observations indicated that the minerals within the CIs were daughter minerals crystallized from an entrapped carbonate- and silica-rich aqueous solution and therefore provided useful information for evaluating the formation models of granitic pegmatites.

  8. The Solubility of Tugarinovite (MoO2) in H2O at Elevated Temperatures and Pressures

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Pritam; Anderson, Alan J.; Lee, Thomas; Klemm, Matthias (SFX); (Augsburg)

    2017-12-18

    The solubility of tugarinovite (MoO2) in pure water was investigated at temperatures between 400 and 800°C and at pressures ranging between 95 and 480 MPa by using in situ synchrotron X-ray fluorescence (SXRF) to separately analyze high temperature aqueous solutions in a hydrothermal diamond anvil cell (HDAC). The concentration of molybdenum in the fluid at 400 and 500°C was below detection; however, at temperatures between 600 and 800°C, the solubility of tugarinovite increased with increasing temperature by two orders of magnitude. The molybdenum concentration at 600°C and 800°C is 44 ppm and 658 ppm, respectively. The results complement the data of Kudrin (1985) and provide the first measurement of MoO2solubility at pressure and temperature conditions comparable to intrusion-related Mo deposit formation. The data are also relevant to the study of water chemistry and corrosion product transport in supercritical-water-cooled reactors, where Mo-bearing steel alloys interact with aqueous solutions at temperatures greater than 600°C. The application of in situ SXRF to solubility measurements of sparingly soluble minerals is recommended because it circumvents analytical uncertainties inherent in determinations obtained by quenching and weight loss measurements.

  9. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, A.S.; Peshkov, L.P.; Rozin, M.M.; Shestov, A.G.

    1983-01-01

    An elevator is proposed which includes a body, a flap, a lock with a catch and a spring-loaded shut-off clamp in the form of upper and lower horizontal levers which are connected by a handle and an axle and one end of which is made in the form of an eccentric cam. The size of the eccentricity of the cam of the levers is increased toward the handle of the clamp in order to increase the operational reliability and to extend the service life.

  10. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Rastorguyev, M.A.; Maloyarovslavtesv, D.A.; Prokopov, O.I.; Tukayev, Sh.V.; Zanilov, I.F.

    1983-01-01

    An elevator is proposed which includes a body with a turning collar locking device and a rod with longitudinal grooves, which are flexibly linked with jaws positioned in grooves in the body. To increase safety through ensuring automatic locking of the jaws in the closed position, the locking device is made in the form of head on wedges, spring loaded relative to the collar and made with cams and positioned with the capability of interacting with the grooves of the rod and through the cams with the collar.

  11. Measurements of capillary pressure and electric permittivity of gas-water systems in porous media at elevated pressures : Application to geological storage of CO2 in aquifers and wetting behavior in coal

    NARCIS (Netherlands)

    Plug, W.J.

    2007-01-01

    Sequestration of CO2 in aquifers and coal layers is a promising technique to reduce greenhouse gas emissions. Considering the reservoir properties, e.g. wettability, heterogeneity and the caprocks sealing capacity, the capillary pressure is an important measure to evaluate the efficiency, the

  12. Crystallization in the systems Cu-I-HI-H2O and CuI-HI-H2O at elevated temperatures and pressures

    International Nuclear Information System (INIS)

    Popolitov, V.I.; Mininzon, Yu.M.

    1983-01-01

    Physicochemical investigation on synthesis and recrystallization of copper monoiodide monocrystals in the systems CU-I-HI-H 2 O and CuI-HI-W 2 O at high temperatures and pressures (200-300 deg and 50-160 atm) has been carried out. The optimum conditions for the growth of the Main tetrahedral facet (111) are clarified. The conditions are as follows: aqueous solution concentration Csub(HI)=32-35 mas.%, temperature 230-270 deg and external temperature gap 25-35 deg. Depending on synthesis conditions monocrystals CUI are prepared with different morphology of tetrahedral and cubooctahedral image. Kinetic regularities of CuI monocrystal preparation are presented and their physical properties, luminescence in particular, are studied

  13. Bucket elevator

    OpenAIRE

    Chromek, Jiří

    2013-01-01

    Cílem této bakalářské práce je návrh svislého korečkového elevátoru, který má sloužit k dopravě obilovin s dopravní výškou 19 m a dopravovaným množstvím 100 t/hod. Práce se skládá z popisu korečkového elevátoru a jeho hlavních částí, zmiňující se v úvodní rešerši. Tato práce je zaměřena na funkční a kapacitní výpočet, určení pohonu a napínacího zařízení. Další výpočet je kontrolní, skládající se z pevnostní kontroly hnacího hřídele, výpočtu pera, životnosti ložisek a výpočtu napínacího zaříze...

  14. Behaviour of a pre-stressed concrete pressure-vessel subjected to a high temperature gradient; Comportement d'un caisson en beton precontraint soumis a un gradient de temperature eleve

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Bonvalet, Ch; Dawance, G; Marechal, J C [Centre Experimental de Recherches et d' Etudes du Batiment et des Travaux Publics (CEBTP), 76 - Harfleur (France)

    1965-07-01

    After a review of the problems presented by pressure-vessels for atomic reactors (shape of the vessel, pressures, openings, foundations, etc.) the advantages of pre-stressed concrete vessels with respect to steel ones are given. The use of pre-stressed concrete vessels however presents many difficulties connected with the properties of concrete. Thus, because of the absence of an exact knowledge of the material, it is necessary to place a sealed layer of steel against the concrete, to have a thermal insulator or a cooling circuit for limiting the deformations and stresses, etc. It follows that the study of the behaviour of pre-stressed concrete and of the vessel subjected- to a high temperature gradient can yield useful information. A one-tenth scale model of a pre-stressed concrete cylindrical vessel without any side openings and without a base has been built. Before giving a description of the tests the authors consider some theoretical aspects concerning 'scale model-actual structure' similitude conditions and the calculation of the thermal and mechanical effects. The pre-stressed concrete model was heated internally by a 'pyrotenax' element and cooled externally by a very strong air current. The concrete was pre-stressed using horizontal and vertical cables held at 80 kg/cm{sup 2}; the thermal gradient was 160 deg. C. During the various tests, measurements were made of the overall and local deformations, the changes in water content, the elasticity modulus, the stress and creep of the cables and the depths of the cracks. The overall deformations observed are in line with thermal deformation theories and the creep of the cables attained 20 to 30 per cent according to their position relative to the internal surface. The dynamic elasticity modulus decreased by half but the concrete keeps its good mechanical properties. Finally, cracks 8 to 12 cm deep and 2 to 3 mms wide appeared in that part of the concrete which was not pre-stressed. The results obtained make it

  15. Behaviour of a pre-stressed concrete pressure-vessel subjected to a high temperature gradient; Comportement d'un caisson en beton precontraint soumis a un gradient de temperature eleve

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Bonvalet, Ch.; Dawance, G.; Marechal, J.C. [Centre Experimental de Recherches et d' Etudes du Batiment et des Travaux Publics (CEBTP), 76 - Harfleur (France)

    1965-07-01

    After a review of the problems presented by pressure-vessels for atomic reactors (shape of the vessel, pressures, openings, foundations, etc.) the advantages of pre-stressed concrete vessels with respect to steel ones are given. The use of pre-stressed concrete vessels however presents many difficulties connected with the properties of concrete. Thus, because of the absence of an exact knowledge of the material, it is necessary to place a sealed layer of steel against the concrete, to have a thermal insulator or a cooling circuit for limiting the deformations and stresses, etc. It follows that the study of the behaviour of pre-stressed concrete and of the vessel subjected- to a high temperature gradient can yield useful information. A one-tenth scale model of a pre-stressed concrete cylindrical vessel without any side openings and without a base has been built. Before giving a description of the tests the authors consider some theoretical aspects concerning 'scale model-actual structure' similitude conditions and the calculation of the thermal and mechanical effects. The pre-stressed concrete model was heated internally by a 'pyrotenax' element and cooled externally by a very strong air current. The concrete was pre-stressed using horizontal and vertical cables held at 80 kg/cm{sup 2}; the thermal gradient was 160 deg. C. During the various tests, measurements were made of the overall and local deformations, the changes in water content, the elasticity modulus, the stress and creep of the cables and the depths of the cracks. The overall deformations observed are in line with thermal deformation theories and the creep of the cables attained 20 to 30 per cent according to their position relative to the internal surface. The dynamic elasticity modulus decreased by half but the concrete keeps its good mechanical properties. Finally, cracks 8 to 12 cm deep and 2 to 3 mms wide appeared in that part of the concrete which was not pre-stressed. The

  16. Elevated blood pressure in cytochrome P4501A1 knockout mice is associated with reduced vasodilation to omega − 3 polyunsaturated fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Agbor, Larry N.; Walsh, Mary T.; Boberg, Jason R.; Walker, Mary K., E-mail: mwalker@salud.unm.edu

    2012-11-01

    In vitro cytochrome P4501A1 (CYP1A1) metabolizes omega − 3 polyunsaturated fatty acids (n − 3 PUFAs); eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), primarily to 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP), respectively. These metabolites have been shown to mediate vasodilation via increases in nitric oxide (NO) and activation of potassium channels. We hypothesized that genetic deletion of CYP1A1 would reduce vasodilatory responses to n − 3 PUFAs, but not the metabolites, and increase blood pressure (BP) due to decreases in NO. We assessed BP by radiotelemetry in CYP1A1 wildtype (WT) and knockout (KO) mice ± NO synthase (NOS) inhibitor. We also assessed vasodilation to acetylcholine (ACh), EPA, DHA, 17,18-EEQ and 19,20-EDP in aorta and mesenteric arterioles. Further, we assessed vasodilation to an NO donor and to DHA ± inhibitors of potassium channels. CYP1A1 KO mice were hypertensive, compared to WT, (mean BP in mm Hg, WT 103 ± 1, KO 116 ± 1, n = 5/genotype, p < 0.05), and exhibited a reduced heart rate (beats per minute, WT 575 ± 5; KO 530 ± 7; p < 0.05). However, BP responses to NOS inhibition and vasorelaxation responses to ACh and an NO donor were normal in CYP1A1 KO mice, suggesting that NO bioavailability was not reduced. In contrast, CYP1A1 KO mice exhibited significantly attenuated vasorelaxation responses to EPA and DHA in both the aorta and mesenteric arterioles, but normal vasorelaxation responses to the CYP1A1 metabolites, 17,18-EEQ and 19,20-EDP, and normal responses to potassium channel inhibition. Taken together these data suggest that CYP1A1 metabolizes n − 3 PUFAs to vasodilators in vivo and the loss of these vasodilators may lead to increases in BP. -- Highlights: ► CYP1A1 KO mice are hypertensive. ► CYP1A1 KO mice exhibit reduced vasodilation responses to n-3 PUFAs. ► Constitutive CYP1A1 expression regulates blood pressure and vascular function.

  17. Marinobufagenin is related to elevated central and 24-h systolic blood pressures in young black women: the African-PREDICT Study.

    Science.gov (United States)

    Strauss, Michél; Smith, Wayne; Wei, Wen; Fedorova, Olga V; Schutte, Aletta E

    2018-03-01

    Marinobufagenin (MBG) is an endogenous steroidal α1-Na + K + -ATPase inhibitor. Because of its role in sodium handling, MBG has been associated with both antihypertensive and prohypertensive effects in normal physiology and pathology. MBG is positively associated with blood pressure in Dahl salt-sensitive rats exhibiting a similar hypertensive phenotype to black populations, characterized by impaired urinary Na + excretion. However, clinical studies exploring blood pressure (BP)-related effects of MBG in black populations are scant. We determined whether the MBG/Na + ratio (assessing the effectiveness of Na + excretion resistance to MBG) is related to systolic BP (SBP) in young black men and women, compared to whites. We included 331 apparently healthy participants (20-30 years) (42.9% black, 43.8% men) on a habitual diet. We obtained 24-h and central SBP, and 24-h urinary Na + and MBG levels. We found no ethnic differences in MBG, Na + or MBG/Na + . MBG excretion correlated positively with Na + excretion in all groups and to SBP in white men and black women (p ≤ 0.011). In black women only SBP related positively to MBG/Na + in single and multi-variable adjusted regression models: central SBP (R 2  = 0.26; ß = 0.28; p = 0.039), 24-h SBP (R 2  = 0.46; ß = 0.30; p = 0.011), daytime (R 2  = 0.38; ß = 0.28; p = 0.023) and nighttime SBP (R 2  = 0.38; ß = 0.33; p = 0.009). In contrast, inverse associations of MBG/Na + with nighttime SBP were evident in white women (r = -0.20; p = 0.038) but lost significance after multiple adjustments (R 2  = 0.36; ß = -0.13; p = 0.12). We found independent positive associations of SBP with MBG/Na + in black women. This data supports the concept that reduced MBG-mediated Na + excretion can contribute to adverse hemodynamics.

  18. Elevated blood pressure in cytochrome P4501A1 knockout mice is associated with reduced vasodilation to omega − 3 polyunsaturated fatty acids

    International Nuclear Information System (INIS)

    Agbor, Larry N.; Walsh, Mary T.; Boberg, Jason R.; Walker, Mary K.

    2012-01-01

    In vitro cytochrome P4501A1 (CYP1A1) metabolizes omega − 3 polyunsaturated fatty acids (n − 3 PUFAs); eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), primarily to 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP), respectively. These metabolites have been shown to mediate vasodilation via increases in nitric oxide (NO) and activation of potassium channels. We hypothesized that genetic deletion of CYP1A1 would reduce vasodilatory responses to n − 3 PUFAs, but not the metabolites, and increase blood pressure (BP) due to decreases in NO. We assessed BP by radiotelemetry in CYP1A1 wildtype (WT) and knockout (KO) mice ± NO synthase (NOS) inhibitor. We also assessed vasodilation to acetylcholine (ACh), EPA, DHA, 17,18-EEQ and 19,20-EDP in aorta and mesenteric arterioles. Further, we assessed vasodilation to an NO donor and to DHA ± inhibitors of potassium channels. CYP1A1 KO mice were hypertensive, compared to WT, (mean BP in mm Hg, WT 103 ± 1, KO 116 ± 1, n = 5/genotype, p < 0.05), and exhibited a reduced heart rate (beats per minute, WT 575 ± 5; KO 530 ± 7; p < 0.05). However, BP responses to NOS inhibition and vasorelaxation responses to ACh and an NO donor were normal in CYP1A1 KO mice, suggesting that NO bioavailability was not reduced. In contrast, CYP1A1 KO mice exhibited significantly attenuated vasorelaxation responses to EPA and DHA in both the aorta and mesenteric arterioles, but normal vasorelaxation responses to the CYP1A1 metabolites, 17,18-EEQ and 19,20-EDP, and normal responses to potassium channel inhibition. Taken together these data suggest that CYP1A1 metabolizes n − 3 PUFAs to vasodilators in vivo and the loss of these vasodilators may lead to increases in BP. -- Highlights: ► CYP1A1 KO mice are hypertensive. ► CYP1A1 KO mice exhibit reduced vasodilation responses to n-3 PUFAs. ► Constitutive CYP1A1 expression regulates blood pressure and vascular function.

  19. Technology, safety and costs of decommissioning a reference pressurized water reactor power station: Technical support for decommissioning matters related to preparation of the final decommissioning rule

    International Nuclear Information System (INIS)

    Konzek, G.J.; Smith, R.I.

    1988-07-01

    Preparation of the final Decommissioning Rule by the Nuclear Regulatory Commission (NRC) staff has been assisted by Pacific Northwest Laboratory (PNL) staff familiar with decommissioning matters. These efforts have included updating previous cost estimates developed during the series of studies on conceptually decommissioning reference licensed nuclear facilities for inclusion in the Final Generic Environmental Impact Statement (FGEIS) on decommissioning; documenting the cost updates; evaluating the cost and dose impacts of post-TMI-2 backfits on decommissioning; developing a revised scaling formula for estimating decommissioning costs for reactor plants different in size from the reference pressurized water reactor (PWR) described in the earlier study; defining a formula for adjusting current cost estimates to reflect future escalation in labor, materials, and waste disposal costs; and completing a study of recent PWR steam generator replacements to determine realistic estimates for time, costs and doses associated with steam generator removal during decommissioning. This report presents the results of recent PNL studies to provide supporting information in four areas concerning decommissioning of the reference PWR: updating the previous cost estimates to January 1986 dollars; assessing the cost and dose impacts of post-TMI-2 backfits; assessing the cost and dose impacts of recent steam generator replacements; and developing a scaling formula for plants different in size than the reference plant and an escalation formula for adjusting current cost estimates for future escalation

  20. Microstructure and elevated-temperature tensile properties of differential pressure sand cast Mg-4Y-3Nd-0.5Zr alloy

    Directory of Open Access Journals (Sweden)

    Hong-hui Liu

    2016-01-01

    Full Text Available The microstructures of an Mg-4Y-3Nd-0.5Zr alloy by differential pressure casting were investigated using scanning electron microscopy (SEM and transmission electron microscopy (TEM, and its tensile deformation behavior was measured using a Gleeble1500D themo-simulation machine in the temperature range of 200 to 400 °C at initial strain rates of 5×10-4 to 10-1 s-1. Results show that the as-cast microstructure consists of primary α-Mg phase and bone-shaped Mg5RE eutectic phase distributed along the grain boundary. The eutectic phase is dissolved into the matrix after solution treatment and subsequently precipitates during peak aging. Tensile deformation tests show that the strain rate has little effect on stress under 300 °C. Tensile stress decreases with an increase in temperature and the higher strain rate leads to an increase in stress above 300 °C. The fracture mechanism exhibits a mixed quasi-cleavage fracture at 200 °C, while the fracture above 300 °C is a ductile fracture. The dimples are melted at 400 °C with the lowest strain rate of 10-4 s-1.

  1. Characterizing the effects of elevated temperature on the air void pore structure of advanced gas-cooled reactor pressure vessel concrete using x-ray computed tomography

    Directory of Open Access Journals (Sweden)

    Withers P.J.

    2013-07-01

    Full Text Available X-ray computed tomography (X-ray CT has been applied to nondestructively characterise changes in the microstructure of a concrete used in the pressure vessel structure of Advanced Gas-cooled Reactors (AGR in the UK. Concrete specimens were conditioned at temperatures of 105 °C and 250 °C, to simulate the maximum thermal load expected to occur during a loss of coolant accident (LOCA. Following thermal treatment, these specimens along with an unconditioned control sample were characterised using micro-focus X-ray CT with a spatial resolution of 14.6 microns. The results indicate that the air void pore structure of the specimens experienced significant volume changes as a result of the increasing temperature. The increase in the porous volume was more prevalent at 250 °C. Alterations in air void size distributions were characterized with respect to the unconditioned control specimen. These findings appear to correlate with changes in the uni-axial compressive strength of the conditioned concrete.

  2. Excess of Aminopeptidase A in the Brain Elevates Blood Pressure via the Angiotensin II Type 1 and Bradykinin B2 Receptors without Dipsogenic Effect

    Directory of Open Access Journals (Sweden)

    Takuto Nakamura

    2017-01-01

    Full Text Available Aminopeptidase A (APA cleaves angiotensin (Ang II, kallidin, and other related peptides. In the brain, it activates the renin angiotensin system and causes hypertension. Limited data are available on the dipsogenic effect of APA and pressor effect of degraded peptides of APA such as bradykinin. Wistar-Kyoto rats received intracerebroventricular (icv APA in a conscious, unrestrained state after pretreatment with (i vehicle, (ii 80 μg of telmisartan, an Ang II type-1 (AT1 receptor blocker, (iii 800 nmol of amastatin, an aminopeptidase inhibitor, and (iv 1 nmol of HOE-140, a bradykinin B2 receptor blocker. Icv administration of 400 and 800 ng of APA increased blood pressure by 12.6 ± 3.0 and 19.0 ± 3.1 mmHg, respectively. APA did not evoke drinking behavior. Pressor response to APA was attenuated on pretreatment with telmisartan (vehicle: 22.1 ± 2.2 mmHg versus telmisartan: 10.4 ± 3.2 mmHg. Pressor response to APA was also attenuated with amastatin and HOE-140 (vehicle: 26.5 ± 1.1 mmHg, amastatin: 14.4 ± 4.2 mmHg, HOE-140: 16.4 ± 2.2 mmHg. In conclusion, APA increase in the brain evokes a pressor response via enzymatic activity without dipsogenic effect. AT1 receptors and B2 receptors in the brain may contribute to the APA-induced pressor response.

  3. Abdominal Obesity in German Adolescents Defined by Waist-to-Height Ratio and Its Association to Elevated Blood Pressure: The KiGGS Study

    Directory of Open Access Journals (Sweden)

    Katrin Kromeyer-Hauschild

    2013-04-01

    Full Text Available Objective: The aim of this study was to compare the fixed 0.5 cut-off and the age- and sex-specific 90th percentile (P90 for waist-to-height ratio (WHtR in German adolescents with respect to the prevalence of abdominal obesity and to compare the screening ability of WHtR and BMI to identify hypertensive blood pressure (BP values. Methods: Between 2003 and 2006, the German Health Interview and Examination Survey for Children and Adolescents (KiGGS was carried out including 3,492 boys and 3,321 girls aged 11-17 years. Abdominal obesity was assessed by two WHtR cut-points (P90; 0.5. Hypertensive BP was defined as BP exceeding age-, sex- and height-specific 95th percentiles or the adult threshold for hypertension (140/90 mm Hg. Results: Agreement between the WHtR cut-offs was very good (Kappa 0.89 for boys; 0.81 for girls, and the prevalence of abdominal obesity was slightly higher using P90 (boys 12.0%; girls 11.3% compared to 0.5 (boys 10.7%; girls 8.0%. WHtR and BMI-for-age had equivalent ability to discriminate hypertensive BP (ROC-AUC Conclusion: The fixed 0.5 WHtR cut-off can be used in German adolescents to characterize abdominal obesity. However, WHtR is not suitable as a screening tool for hypertensive BP in adolescents.

  4. Experimental investigation of CO2-brine-rock interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

    Science.gov (United States)

    Rosenbauer, R.J.; Koksalan, T.; Palandri, J.L.

    2005-01-01

    Deep-saline aquifers are potential repositories for excess CO2, currently being emitted to the atmosphere from anthropogenic activities, but the reactivity of supercritical CO2 with host aquifer fluids and formation minerals needs to be understood. Experiments reacting supercritical CO2 with natural and synthetic brines in the presence and absence of limestone and plagioclase-rich arkosic sandstone showed that the reaction of CO2-saturated brine with limestone results in compositional, mineralogical, and porosity changes in the aquifer fluid and rock that are dependent on initial brine composition, especially dissolved calcium and sulfate. Experiments reacting CO2-saturated, low-sulfate brine with limestone dissolved 10% of the original calcite and increased rock porosity by 2.6%. Experiments reacting high-sulfate brine with limestone, both in the presence and absence of supercritical CO2, were characterized by the precipitation of anhydrite, dolomitization of the limestone, and a final decrease in porosity of 4.5%. However, based on favorable initial porosity changes of about 15% due to the dissolution of calcite, the combination of CO2 co-injection with other mitigation strategies might help alleviate some of the well-bore scale and formation-plugging problems near the injection zone of a brine disposal well in Paradox Valley, Colorado, as well as provide a repository for CO2. Experiments showed that the solubility of CO2 is enhanced in brine in the presence of limestone by 9% at 25 ??C and 6% at 120 ??C and 200 bar relative to the brine itself. The solubility of CO2 is enhanced also in brine in the presence of arkosic sandstone by 5% at 120 ??C and 300 bar. The storage of CO 2 in limestone aquifers is limited to only ionic and hydraulic trapping. However, brine reacted with supercritical CO2 and arkose yielded fixation and sequestration of CO2 in carbonate mineral phases. Brine desiccation was observed in all experiments containing a discrete CO2 phase

  5. Elevated lactate during psychogenic hyperventilation

    NARCIS (Netherlands)

    ter Avest, E.; Patist, F. M.; ter Maaten, J. C.; Nijsten, M. W. N.

    Study objective Elevated arterial lactate levels are closely related to morbidity and mortality in various patient categories. In the present retrospective study, the relation between arterial lactate, partial pressure of carbon dioxide (Pco(2)) and pH was systematically investigated in patients who

  6. Pressure Effect on Entrance Flow

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Couch, Mark

    1997-01-01

    The paper reports on experimentally determined pressure drops associated with orifice and capillary dies, where the exit pressure is elevated. The effect of hydrostatic pressure up to 70 MPa is reported for PS, LDPE and PP melts.......The paper reports on experimentally determined pressure drops associated with orifice and capillary dies, where the exit pressure is elevated. The effect of hydrostatic pressure up to 70 MPa is reported for PS, LDPE and PP melts....

  7. Wavelet entropy characterization of elevated intracranial pressure.

    Science.gov (United States)

    Xu, Peng; Scalzo, Fabien; Bergsneider, Marvin; Vespa, Paul; Chad, Miller; Hu, Xiao

    2008-01-01

    Intracranial Hypertension (ICH) often occurs for those patients with traumatic brain injury (TBI), stroke, tumor, etc. Pathology of ICH is still controversial. In this work, we used wavelet entropy and relative wavelet entropy to study the difference existed between normal and hypertension states of ICP for the first time. The wavelet entropy revealed the similar findings as the approximation entropy that entropy during ICH state is smaller than that in normal state. Moreover, with wavelet entropy, we can see that ICH state has the more focused energy in the low wavelet frequency band (0-3.1 Hz) than the normal state. The relative wavelet entropy shows that the energy distribution in the wavelet bands between these two states is actually different. Based on these results, we suggest that ICH may be formed by the re-allocation of oscillation energy within brain.

  8. Dry reforming of methane at elevated pressures

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, L.; Lou, Y.; Jentys, A.; Lercher, J.A. [Technische Universitaet Muenchen (Germany); Herrera Delgado, K.; Kahle, L.; Deutschmann, O. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany)

    2013-11-01

    The dry reforming of methane (CO{sub 2} + CH{sub 4} {yields} 2 H{sub 2} + 2 CO) can be an alternative to steam (CH{sub 4} + H{sub 2}O {yields} 3 H{sub 2} + CO) or autothermal reforming for the production of CO rich syngas. However, its high tendency to coking has prevented the process from been applied in chemical industry. Due to pricing and availability base metals are preferred as active metals in dry reforming, even though they are more prone to coke deposition. To overcome this drawback and create suitable base metal catalysts, a detailed understanding of the carbon deposition mechanism is mandatory. In the work presented we compare the reactions leading to coke buildup on Nickel and Platinum at reaction conditions close to technical application (850 C, 10 bar). We analyzed the deposited coke by reactant isotope labeling ({sup 13}CO{sub 2}), SEM, TEM and TPO and revealed that the main deposits after 2 hours of reaction are carbon-nano-tubes. The coke formation on the Ni catalyst was about ten times higher compared to the Pt catalysts. The isotope composition of the coke indicated that on the Nickel both reactants ({sup 12}CH{sub 4} and {sup 13}CO{sub 2}) contributed to the carbon formation, whereas on Platinum coke was formed predominately from {sup 12}CH{sub 4}. Numerical simulations of the reaction rates of the individual pathways support the experimentally derived kinetic results and give insights in the main reaction routes on the catalytic surfaces. Based on the findings we propose a carbon deposition mechanism that explains the stronger resistance of Pt based catalysts against coking. The authors gratefully acknowledge the financial support from BMWi (0320327856D) and from DFG (LE 1187/12). (orig.) (Published in summary form only)

  9. Coolant mixing in pressurized water reactors. Pt. 1. Feasibility of closed analytical solutions and simulation of the mixing with CFX-4. Final report

    International Nuclear Information System (INIS)

    Grunwald, G.; Hoehne, T.; Prasser, H.M.; Rohde, U.

    2001-10-01

    The project was aimed at the analytical and numerical simulation of coolant mixing in the downcomer and the lower plenum of PWRs. Generally, the coolant mixing is of relevance for two classes of accident scenarios - boron dilution and cold water transients. For the investigation of the relevant mixing phenomena, the Rossendorf test facility ROCOM has been designed. ROCOM is a 1:5 scaled Plexiglas trademark model of the PWR Konvoi allowing velocity measurements by the LDA technique. Design and construction of the ROCOM facility including the measurement equipment were performed in a second part of the project. For the design of the facility, CFD calculations were performed to analyze the scaling of the model. It was found, that the scaling of 1:5 to the prototype meets both: physical and economical demands. A theoretical 2D-model of the downcomer flow was developed based on the potential theory. The coolant inlet is represented by mass sources. Potential vortices were superposed to describe large scale recirculations. However, the method requires an a-priory knowledge of the location and intensity of the vorticity sources. Therefore, the main goal of the project was the numerical simulation of the coolant mixing of different PWRs. The temperature and boron concentration fields established by the coolant mixing during nominal and transient flow conditions in the pressure vessel of the PWR Konvoi and the Russian type WWER-440 were investigated. The calculations were carried out with the CFD-code CFX 4. The results of the CFD calculation are found in the final report. The report is based on the Ph.D. work of T. Hoehne. (orig.) [de

  10. National Elevation Dataset (NED)

    Data.gov (United States)

    Kansas Data Access and Support Center — The U.S. Geological Survey has developed a National Elevation Database (NED). The NED is a seamless mosaic of best-available elevation data. The 7.5-minute elevation...

  11. Elevated Liver Enzymes

    Science.gov (United States)

    Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

  12. Final Technical Report on STTR Project DE-FG02-02ER86145 Pressurized RF Cavities for Muon Ionization Cooling

    International Nuclear Information System (INIS)

    Rolland Johnson

    2006-01-01

    This project was to design and build an RF test cell (TC), which could be operated at 800 MHz, filled with high pressure gases including hydrogen, at temperatures down to that of liquid nitrogen, in strong magnetic fields, in a strong radiation environment, and with interchangeable electrodes, in order to examine the use of high-pressure RF cavities for muon beam cooling

  13. High-sensitivity Cardiac Troponin Elevation after Electroconvulsive Therapy (ECT)

    Science.gov (United States)

    Duma, Andreas; Pal, Swatilika; Johnston, Joshua; Helwani, Mohammad A.; Bhat, Adithya; Gill, Bali; Rosenkvist, Jessica; Cartmill, Christopher; Brown, Frank; Miller, J. Philip; Scott, Mitchell G; Sanchez-Conde, Francisco; Jarvis, Michael; Farber, Nuri B.; Zorumski, Charles F.; Conway, Charles; Nagele, Peter

    2017-01-01

    Background While electroconvulsive therapy (ECT) is widely regarded as a life-saving and safe procedure, evidence regarding its effects on myocardial cell injury are sparse. The objective of this investigation was to determine incidence and magnitude of new cardiac troponin elevation after ECT using a novel high-sensitivity cardiac troponin I (hscTnI) assay. Methods This was a prospective cohort study in adult patients undergoing ECT in a single academic center (up to three ECT treatments per patient). The primary outcome was new hscTnI elevation after ECT, defined as an increase of hscTnI >100% after ECT compared to baseline with at least one value above the limit of quantification (10 ng/L). 12-lead ECG and hscTnI values were obtained prior to and 15–30 minutes after ECT; in a subset of patients an additional 2-hour hscTnI value was obtained. Results The final study population was 100 patients and a total of 245 ECT treatment sessions. Eight patients (8/100, 8%) experienced new hscTnI elevation after ECT with a cumulative incidence of 3.7% (9/245 treatments; one patient had two hscTnI elevations), two of whom had a non-ST-elevation myocardial infarction (incidence 2/245, 0.8%). Median hscTnI concentrations did not increase significantly after ECT. Tachycardia and/or elevated systolic blood pressure developed after approximately two thirds of ECT treatments. Conclusions ECT appears safe from a cardiac standpoint in a large majority of patients. A small subset of patients with pre-existing cardiovascular risk factors, however, may develop new cardiac troponin elevation after ECT, the clinical relevance of which is unclear in the absence of signs of myocardial ischemia. PMID:28166110

  14. Pressure dependence of conductivity

    International Nuclear Information System (INIS)

    Bracewell, B.L.; Hochheimer, H.D.

    1993-01-01

    The overall objectives of this work were to attempt the following: (1) Measure the pressure dependence of the electrical conductivity of several quasi-one-dimensional, charge-density-wave solids, including measurements along various crystal directions. (2) Measure photocurrents in selected MX solids at ambient and elevated pressures. (3) Measure the resonance Raman spectra for selected MX solids as a function of pressure

  15. Effects of isoflavone-containing soya protein on ex vivo cholesterol efflux, vascular function and blood markers of CVD risk in adults with moderately elevated blood pressure: a dose-response randomised controlled trial.

    Science.gov (United States)

    Richter, Chesney K; Skulas-Ray, Ann C; Fleming, Jennifer A; Link, Christina J; Mukherjea, Ratna; Krul, Elaine S; Kris-Etherton, Penny M

    2017-05-01

    Emerging CVD risk factors (e.g. HDL function and central haemodynamics) may account for residual CVD risk experienced by individuals who meet LDL-cholesterol and blood pressure (BP) targets. Recent evidence suggests that these emerging risk factors can be modified by polyphenol-rich interventions such as soya, but additional research is needed. This study was designed to investigate the effects of an isoflavone-containing soya protein isolate (delivering 25 and 50 g/d soya protein) on HDL function (i.e. ex vivo cholesterol efflux), macrovascular function and blood markers of CVD risk. Middle-aged adults (n 20; mean age=51·6 (sem 6·6) years) with moderately elevated brachial BP (mean systolic BP=129 (sem 9) mmHg; mean diastolic BP=82·5 (sem 8·4) mmHg) consumed 0 (control), 25 and 50 g/d soya protein in a randomised cross-over design. Soya and control powders were consumed for 6 weeks each with a 2-week compliance break between treatment periods. Blood samples and vascular function measures were obtained at baseline and following each supplementation period. Supplementation with 50 g/d soya protein significantly reduced brachial diastolic BP (-2·3 mmHg) compared with 25 g/d soya protein (Tukey-adjusted P=0·03) but not the control. Soya supplementation did not improve ex vivo cholesterol efflux, macrovascular function or other blood markers of CVD risk compared with the carbohydrate-matched control. Additional research is needed to clarify whether effects on these CVD risk factors depend on the relative health of participants and/or equol producing capacity.

  16. Development of solar wind shock models with tensor plasma pressure for data analysis. Final technical report, 1 Aug 1970--31 Dec 1975

    International Nuclear Information System (INIS)

    Abraham-shrauner, B.

    1975-01-01

    The development of solar wind shock models with tensor plasma pressure and the comparison of some of the shock models with the satellite data from Pioneer 6 through Pioneer 9 are reported. Theoretically, difficulties were found in non-turbulent fluid shock models for tensor pressure plasmas. For microscopic shock theories nonlinear growth caused by plasma instabilities was frequently not clearly demonstrated to lead to the formation of a shock. As a result no clear choice for a shock model for the bow shock or interplanetary tensor pressure shocks emerged

  17. Vessels for elevated temperature service

    International Nuclear Information System (INIS)

    O'Donnell, W.J.; Porowski, J.S.

    1983-01-01

    The subject is covered in chapters, entitled: introduction (background; elevated temperature concerns; design tools); design of pressure vessels for elevated temperature per ASME code; basic elevated temperature failure modes; allowable stresses and strains per ASME code (basic allowable stress limits; ASME code limits for bending; time-fraction summations; strain limits; buckling and instability; negligible creep and stress-rupture effects); combined membrane and bending stresses in creep regime; thermal stress cycles; bounding methods based on elastic core concept (bounds on accumulated strains; more accurate bounds; strain ranges; maximum stresses; strains at discontinuities); elastic follow-up; creep strain concentrations; time-dependent fatigue (combined creep rupture and fatigue damage; limits for inelastic design analyses; limits for elastic design analyses); flaw evaluation techniques; type 316 stainless steel; type 304 stainless steel; steel 2 1/4Cr1Mo; Inconel 718; Incolloy 800; Hastelloy X; detailed inelastic design analyses. (U.K.)

  18. Blood Pressure Measurement: Clinic, Home, Ambulatory, and Beyond

    Science.gov (United States)

    Drawz, Paul E.; Abdalla, Mohamed; Rahman, Mahboob

    2014-01-01

    Blood pressure has traditionally been measured in the clinic setting using the auscultory method and a mercury sphygmomanometer. Technological advances have led to improvements in measuring clinic blood pressure and allowed for measuring blood pressures outside the clinic. This review outlines various methods for evaluating blood pressure and the clinical utility of each type of measurement. Home blood pressures and 24 hour ambulatory blood pressures have improved our ability to evaluate risk for target organ damage and hypertension related morbidity and mortality. Measuring home blood pressures may lead to more active participation in health care by patients and has the potential to improve blood pressure control. Ambulatory blood pressure monitoring enables the measuring nighttime blood pressures and diurnal changes, which may be the most accurate predictors of risk associated with elevated blood pressure. Additionally, reducing nighttime blood pressure is feasible and may be an important component of effective antihypertensive therapy. Finally, estimating central aortic pressures and pulse wave velocity are two of the newer methods for assessing blood pressure and hypertension related target organ damage. PMID:22521624

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

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, B.

    1985-11-01

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

  20. Storage of hydrogen in advanced high pressure container. Final report for PSO projekt; Lagring af brint i avancerede hoejtryksbeholdere. Slutrapport for PSO-projekt

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, Jens

    2006-04-15

    The objective of the project has been to study barriers for a production of advanced high pressure containers especially suitable for hydrogen, in order to create a basis for a container production in Denmark. The project has primarily focused on future Danish need for hydrogen storage in the MWh area. One task has been to examine requirement specifications for pressure tanks that can be expected in connection with these stores. Six potential storage needs have been identified: (1) Buffer in connection with start-up/regulation on the power grid. (2) Hydrogen and oxygen production. (3) Buffer store in connection with VEnzin vision. (4) Storage tanks on hydrogen filling stations. (5) Hydrogen for the transport sector from 1 TWh surplus power. (6) Tanker transport of hydrogen. Requirements for pressure containers for the above mentioned use have been examined. The connection between stored energy amount, pressure and volume compared to liquid hydrogen and oil has been stated in tables. As starting point for production technological considerations and economic calculations of various container concepts, an estimation of laminate thickness in glass-fibre reinforced containers with different diameters and design print has been made, for a 'pure' fibre composite container and a metal/fibre composite container respectively. (BA)

  1. Iowa Bedrock Surface Elevation

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This Digital Elevation Model (DEM) of the bedrock surface elevation in Iowa was compiled using all available data, principally information from GEOSAM, supplemented...

  2. Final report for the 1st ex-vessel neutron dosimetry installations and evaluations for Kori unit 2 reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Chang, Kee Ok; Gong, Un Sik; Choi, Kwon Jae; Chang, Jong Hwa; Lim, Nam Jin; Hong, Joon Wha; Cheon, Byeong Jin

    2006-11-15

    This report describes a neutron fluence assessment performed for the Kori unit 2 pressure vessel belt line region based on the guidance specified in regulatory guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the belt line region of the pressure vessel. During cycle 20 of reactor operation, an ex-vessel neutron dosimetry program was instituted at Kori unit 2 to provide continuous monitoring of the belt line region of the reactor vessel. The use of the ex-vessel neutron dosimetry program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-vessel neutron dosimetry has been evaluated at the conclusion of cycle 20.

  3. Final Report of the 2nd Ex-Vessel Neutron Dosimetry Installation And Evaluations for Yonggwang Unit 1 Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Chang, Kee Ok; Gong, Un Sik; Choi, Kwon Jae; Chang, Jong Hwa; Li, Nam Jin; Hong, Joon Wha

    2007-01-15

    This report describes a neutron fluence assessment performed for the Yonggwang Unit 1 pressure vessel belt line region based on the guidance specified in Regulatory Guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the belt line region of the pressure vessel. During Cycle 16 of reactor operation, 2nd Ex-Vessel Neutron Dosimetry Program was instituted at Yonggwang Unit 1 to provide continuous monitoring of the belt line region of the reactor vessel. The use of the Ex-Vessel Neutron Dosimetry Program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-Vessel Neutron Dosimetry has been evaluated at the conclusion of Cycle 16.

  4. Final Report of the 2nd Ex-Vessel Neutron Dosimetry Installation And Evaluations for Yonggwang Unit 1 Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Gong, Un Sik; Choi, Kwon Jae; Chung, Kyoung Ki; Kim, Kwan Hyun; Chang, Jong Hwa; Ha, Jea Ju

    2008-01-15

    This report describes a neutron fluence assessment performed for the Kori Unit 2 pressure vessel belt line region based on the guidance specified in Regulatory Guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the belt line region of the pressure vessel. During Cycle 21 of reactor operation, an Ex-Vessel Neutron Dosimetry Program was instituted at Kori Unit 2 to provide continuous monitoring of the belt line region of the reactor vessel. The use of the Ex-Vessel Neutron Dosimetry Program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-Vessel Neutron Dosimetry has been evaluated at the conclusion of Cycle 21.

  5. Final report for the 1st ex-vessel neutron dosimetry installation and evaluations for Kori unit 4 reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Chang, Kee Ok; Gong, Un Sik; Choi, Kwon Jae; Chang, Jong Hwa; Lim, Nam Jin; Hong, Joon Wha; Cheon, Byeong Jin

    2006-11-15

    This report describes a neutron fluence assessment performed for the Kori unit 4 pressure vessel belt line region based on the guidance specified in regulatory guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the belt line region of the pressure vessel. During cycle 16 of reactor operation, an ex-vessel neutron dosimetry program was instituted at Kori unit 4 to provide continuous monitoring of the belt line region of the reactor vessel. The use of the ex-vessel neutron dosimetry program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-vessel neutron dosimetry has been evaluated at the conclusion of cycle 16.

  6. Final report for the 2nd Ex-Vessel Neutron Dosimetry Installations and Evaluations for Yonggwang Unit 2 Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chul; Yoo, Choon Sung; Lee, Sam Lai; Gong, Un Sik; Choi, Kwon Jae; Chung, Kyoung Ki; Kim, Kwan Hyun; Chang, Jong Hwa; Ha, Jea Ju

    2008-01-15

    This report describes a neutron fluence assessment performed for the Yonggwang Unit 2 pressure vessel beltline region based on the guidance specified in Regulatory Guide 1.190. In this assessment, maximum fast neutron exposures expressed in terms of fast neutron fluence (E>1 MeV) and iron atom displacements (dpa) were established for the beltline region of the pressure vessel. During Cycle 16 of reactor operation, an Ex-Vessel Neutron Dosimetry Program was instituted at Yonggwang Unit 2 to provide continuous monitoring of the beltline region of the reactor vessel. The use of the Ex-Vessel Neutron Dosimetry Program coupled with available surveillance capsule measurements provides a plant specific data base that enables the evaluation of the vessel exposure and the uncertainty associated with that exposure over the service life of the unit. Ex-Vessel Neutron Dosimetry has been evaluated at the conclusion of Cycle 16.

  7. Effects of internal gas pressure and microstructure on the mechanisms of hot-pressing and swelling in ceramics. Final report, June 1, 1979-May 31, 1980

    International Nuclear Information System (INIS)

    Solomon, A.A.

    1980-08-01

    The results of the study of the effects of internal and external gas pressures on ceramics are summarized. The new experimental systems for studying these phenomena are described. The study has shown that the rate of volume change in ZnO is linearly related to the total pressure driving force. Swelling and hot-pressing can be described on a consistent basis in terms of this driving force. For ZnO, Ni and UO 2 the rate of volume change is dependent on bulk diffusion. The porosity evolution during swelling is described and the resintering phenomenon is identified. Various models for pore growth and shrinkage are considered and related to the behavior of the different systems

  8. Troponin elevation in subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    Ioannis N. Mavridis

    2015-03-01

    Full Text Available Troponin (tr elevation in aneurysmal subarachnoid hemorrhage (SAH patients is often difficult to be appropriately assessed by clinicians, causing even disagreements regarding its management between neurosurgeons and cardiologists. The purpose of this article was to review the literature regarding the clinical interpretation of tr elevation in SAH. We searched for articles in PubMed using the key words: “troponin elevation” and “subarachnoid hemorrhage”. All of them, as well as relative neurosurgical books, were used for this review. Some type of cardiovascular abnormality develops in most SAH patients. Neurogenic stunned myocardium is a frequent SAH complication, due to catecholamine surge which induces cardiac injury, as evidenced by increased serum tr levels, electrocardiographic (ECG changes and cardiac wall motion abnormalities. Tr elevation, usually modest, is an early and specific marker for cardiac involvement after SAH and its levels peak about two days after SAH. Cardiac tr elevation predictors include poor clinical grade, intraventricular hemorrhage, loss of consciousness at ictus, global cerebral edema, female sex, large body surface area, lower systolic blood pressure, higher heart rate and prolonged Q-Tc interval. Elevated tr levels are associated with disability and death (especially tr >1 μg/L, worse neurological grade, systolic and diastolic cardiac dysfunction, pulmonary congestion, longer intensive care unit stay and incidence of vasospasm. Tr elevation is a common finding in SAH patients and constitutes a rightful cause of worry about the patients' cardiac function and prognosis. It should be therefore early detected, carefully monitored and appropriately managed by clinicians.

  9. Effect of consuming a purple-fleshed sweet potato beverage on health-related biomarkers and safety parameters in Caucasian subjects with elevated levels of blood pressure and liver function biomarkers: a 4-week, open-label, non-comparative trial.

    Science.gov (United States)

    Oki, Tomoyuki; Kano, Mitsuyoshi; Watanabe, Osamu; Goto, Kazuhisa; Boelsma, Esther; Ishikawa, Fumiyasu; Suda, Ikuo

    2016-01-01

    An open-label study with one treatment arm was conducted to investigate changes in health-related biomarkers (blood pressure and liver enzyme activity) and the safety of 4 weeks of consuming a purple-fleshed sweet potato beverage in Caucasian subjects. Twenty healthy adults, 18-70 years of age, with a body mass index >25 kg/m(2), elevated blood pressure and elevated levels of liver function biomarkers consumed two cartons of purple-fleshed sweet potato beverage (125 ml, including 117 mg anthocyanin per carton) daily for 4 weeks. Hematology, serum clinical profile, dipstick urinalysis and blood pressure were determined before consumption, at 2 and 4 weeks of consumption and after a 2-week washout period. A trend was found toward lowering systolic blood pressure during the treatment period (p=0.0590). No significant changes were found in diastolic blood pressure throughout the study period. Systolic blood pressure was significantly lower after 4 weeks of consumption compared with before consumption (p=0.0125) and was significantly higher after the 2-week washout period compared with after consumption (p=0.0496). The serum alanine aminotransferase level significantly increased over time, but aspartate aminotransferase and γ-glutamyltransferase levels stayed within the normal range of reference values. Safety parameters of the blood and urine showed no clinically relevant changes. The consumption of a purple-fleshed sweet potato beverage for 4 weeks resulted in no clinically relevant changes in safety parameters of the blood and urine and showed a trend toward lowering systolic blood pressure.

  10. Industry in the 5th Environmental Outlook. Background information and final conclusions on the future development of environmental pressure (emissions) due to industrial production in the Netherlands

    International Nuclear Information System (INIS)

    Wesselink, L.G.; Elzenga, H.E.; Booij, H.; Peek, K.; Thomas, R.; Duvoort, G.L.; Van Schijndel, M.W.

    2001-01-01

    The present and future development of environmental pressure (here emissions) due to industrial production in the Netherlands are discussed. Results were - strongly aggregated - also presented in the 5th Environmental Outlook. We studied developments in production levels, energy use and emissions of Dutch industry and the effect of environmental policy measures, in the period 1980-2020. We used monitoring data for the period 1980-1998 en two scenarios (Global Competition and European Coordination) for the subsequent 1998-2020 period. It is concluded, that future CO2 emissions due to industrial production will continue to increase, that emissions of fluorinated (Kyoto) gasses will strongly decrease and that emissions of NOx, SO2, VOS en fine particles will continue to decrease. Yet, current environmental policy is insufficient to meet national Dutch emission targets of NOx, SO2, VOS in 2010

  11. Final Report for Award DE-FG02-99ER54554 Kinetics of Electron Fluxes in Low-Pressure Nonthermal Plasmas

    International Nuclear Information System (INIS)

    Uwe Kortshagen

    2004-01-01

    This grant has focused on the study of several aspects of electron kinetics in low pressure plasmas. Entirely new effects arise from the fact that the electron kinetics is governed by non-local effects, in which the electron distribution function is not equilibrium with the local electric field but is governed by spatial transport effects. In this grant, we were able to demonstrate several previously un-studied effects which are a direct result of the nonlocal transport. These are: (1) The existence of a ''convective cell' in electron phase space. The phenomenon was observed and studied in CW plasma conditions. (2) The occurrence of non-collisional cooling of electrons through an effect known as ''diffusive cooling''

  12. De stille elever

    DEFF Research Database (Denmark)

    Winther-Lindqvist, Ditte Alexandra

    2012-01-01

    Det er blevet en afgørende samværskompetence i uddannelsessystemet at stå aktivt frem og deltage verbalt i skoleklassens liv både fagligt og socialt. Men ikke alle elever deltager lige villigt verbalt i plenum. Artiklen handler om de stille elever og konsekvenserne af stillehed i skolen. Det...... foreslås at skolesystemet sanktionerer ældre elever hårdere for stillehed end yngre elever og det forklares med at skolelivet også er en kultivering henimod elevhed som social identitet og denne er der forventning om at eleverne mestrer i udskolingen....

  13. Final report on SIM.M.P-S6: Differential pressure comparison from 50 Pa to 500 Pa with a liquid column manometer between CENAM (Mexico) and INTI-Fisica y Metrologia (Argentina)

    Science.gov (United States)

    Torres-Guzman, Jorge; Forastieri, Juan; Zúñiga, Sinuhé

    2011-01-01

    A differential pressure comparison was performed between CENAM (Mexico) and INTI (Argentina) by means of a liquid column manometer. The measuring range was 50 Pa to 500 Pa. CENAM calibrated the transfer standard at the beginning and at the end of the comparison. The transfer standard used was a Dwyer liquid column manometer model Microtector with an accuracy class of 0.013% of the reading. The compared pressure points were (50, 75, 125, 200, 250, 300, 350, 400, 450, 500) Pa. The uncertainty sources to be evaluated included at least the following: (a) uncertainty due to the standard used by the laboratory; (b) uncertainty due to repeatability; (c) uncertainty due to resolution; (d) uncertainty due to hysteresis; (e) uncertainty due to zero drift. The criteria used to compare the results obtained were the normalized error equation (En). The results obtained by the laboratories were compatible according to the criteria |En| <= 1. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  14. Final Report for the 1st Surveillance Test of the Reactor Pressure Vessel Material (Capsule 2) of Ulchin Nuclear Power Plant Unit 4

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Kee Ok; Kim, Byoung Chul; Lee, Sam Lai (and others)

    2007-04-15

    Surveillance testing for reactor vessel materials is performed in order to evaluate the irradiation embrittlement due to neutrons during operation and set the condition of safe operation of nuclear reactor. The 1st surveillance testing was performed completely by Korea Atomic Energy Research Institute at Daejon after the capsule was transported from Ulchin site including its removal from reactor. Fast neutron fluences for capsules were calculated and various testing including mechanical and chemistry analysis were performed in order to evaluate the integrity of Ulchin Unit 4 reactor vessel during the operation until life time. The evaluation results are as follows; Fast neutron fluences for capsule 2 is 4.306E+18n/cm{sup 2}. The bias factor, the ratio of calculation/measurement, was 0.918 for the 1st testing and the calculational uncertainty,7.0% satisfied the requirement of USNRC Reg.Guide 1.190, 20%. The best estimated neutron fluence for reactor vessel inside surface was 3.615E+18n/cm{sup 2} based on the end of 6th fuel cycle and it was predicted that the fluences of vessel inside surface at 16 and 32EFPY would reach 8.478E+18 and 1.673E+19n/cm{sup 2} based on the current calculation. The result through this analysis for Ulchin Unit 4 showed that there would be no problem for the pressurized thermal shock(PTS) during the operation until design life.

  15. Simultaneous high-temperature removal of alkali and particulates in a pressurized gasification system. Final technical progress report, April 1981-July 1983

    Energy Technology Data Exchange (ETDEWEB)

    Mulik, P.R.; Alvin, M.A.; Bachovchin, D.M.

    1983-09-01

    This program is directed at performing experimental and analytical investigations, deriving system designs, and estimating costs to ascertain the feasibility of using aluminosilicate-based getters for controlling alkali in pressurized gasification systems. Its overall objective is to develop a plan for evaluating a scaled-up version of the gettering process as a unit operation or as an integral part of a particulate removal device. This report describes work completed on the four technical program tasks: Thermodynamic projections; Getter Selection and Qualification; System Performance Projections; and Program Definition for Concept Scale-up during the 27-month contract performance period. Work completed on the thermodynamic projections includes a data base update, development of alkali phase diagrams, and system performance projections. Getter selection and qualification efforts involved over 70 kinetic studies in which a leading candidate getter - emathlite - was selected and characterized. System performance projections identified a packed-bed configuration containing relatively large getter pellets as the preferred contacting device for a full-scale unit. For emathlite, we concluded that full-scale unit bed heights of 2 m or less would be required if we assume annual replacement on the basis of bed saturation capacity. Concept scale-up work involved defining the hardware and test program requirements for further development of the emathlite packed-bed system. 56 references, 80 figures, 74 tables.

  16. Gas separation of landfill gas and other biogases by pressure swing adsorption. Final report. Gastrennung fuer Deponie- und Faulgase mittels Druckwechseltechnik. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pilarczyk, E; Mellech, L

    1986-01-01

    A new PSA-process for recovery of methane with SNG-quality from biogases was developed in the laboratory and successfully tested in field trials at the German landfill Emscherbruch/Gelsenkirchen. A special carbon molecular sieve on which carbon dioxide is adsorbed much faster than methane was proved as the best suited adsorbent for biogas separation. Even part of nitrogen which is mostly contained in landfill gases from leakage air is simultaneously removed from methane together with carbon dioxide by using the carbon molecular sieve. Low quality-SNG with 88-90% by vol. methane could be processed from landfill gas containing up to 15% by vol. nitrogen at an adsorption pressure of 3-9 bar abs. The recovery of methane goes upt to 98%. High quality-SNG can be processed from N/sub 2/-free biogases like sewage gas. The capital and operational cost (not including prepurification) for recovery of low quality-SNG by PSA is estimated to about 0,12 DM/m/sup 3/ SNG. (orig.) With 13 refs., 13 tabs., 16 figs.

  17. Pressure and temperature measurements of cam follower and roller tappet in tribological contact. Final report; Druck- und Temperaturmessungen im Tribokontakt Nocken-Rollenstoessel. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Noronha, A.P.; Glasser, S.; Sadeghi, F.

    2002-12-20

    Tribocontact between cam follower and roller tappet involves mixing and limiting friction states, which causes wear in the form of adhesive corrosion and pitting of surfaces. In cooperation with Purdue University, the influence of microgeometry (surface roughness) and macrogeometry (surface shape) was investigated in order to optimize lubrication for EHD lubrication conditions in contact, thus preventing wear and failure. This component project involves pressure and temperature measurements of cam follower and roller tappet tribocontact using flash-deposited thin film probes. The results are to provide information on design optimization. [German] Im Tribokontakt Nocken-Rollenstoessel herrschen vorwiegend Misch- und Grenzreibungszustaende. Dies fuehrt zu erheblichem Verschleiss in Form von adhaesiv bedingtem Fressen und Pittingbildung durch Oberflaechenzerruettung. Ziel dieses Forschungsvorhabens ist es, in Kooperation mit der Partnerhochschule ''Purdue University'' in den USA, den Einfluss der Mikrogeometrie (Oberflaechenrauheiten) und Makrogeometrie (Oberflaechenform) des Tribokontaktes Nocken-Rollenstoessel hinsichtlich des Betriebsverhaltens zu untersuchen, um Kenntnisse zur Verbesserung der Schmierbedingungen zu gewinnen, so dass im Kontakt elastohydrodynamische (EHD) Schmierungsverhaeltnisse realisiert werden und dadurch ein Ausfall aufgrund von Verschleiss ausgeschlossen wird. Im Rahmen dieses Teilvorhabens sollten Druck- und Temperaturmessungen mittels aufgedampfter Duennschichtaufnehmer im Tribokontakt, Nocken-Rollenstoessel, durchgefuehrt werden, um die theoretischen Forschungsarbeiten, welche in der Purdue University erarbeitet werden, zu untermauern. Beide Arbeiten werden somit neue Erkenntnisse zur konstruktiven Auslegung von verschleissfreien Nocken-Stoessel-Paarungen liefern. (orig.)

  18. Final Report for the 1st Surveillance Test of the Reactor Pressure Vessel Material (CAPSULE 2) of Ulchin Nuclear Power Plant Unit 3

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Kee Ok; Kim, Byoung Chul; Lee, Sam Lai (and others)

    2006-12-15

    Surveillance testing for reactor vessel materials is performed in order to evaluate the irradiation embrittlement due to neutrons during operation and set the condition of safe operation of nuclear reactor. The 1st surveillance testing was performed completely by Korea Atomic Energy Research Institute at Taejon after the capsule was transported from Ulchin site including its removal from reactor. Fast neutron fluences for capsules were calculated and various testing including mechanical and chemistry analysis were performed in order to evaluate the integrity of Ulchin unit 3 reactor vessel during the operation until life time. The evaluation results are as follows; Fast neutron fluences for capsule 2 is 4.674E 18n/cm{sup 2}. The bias factor, the ratio of calculation/measurement, was 0.920 for the 1st testing and the calculational uncertainty,7.0% satisfied the requirement of USNRC Reg.Guide 1.190, 20%. The best estimated neutron fluence for reactor vessel inside surface was 3.913E 18n/cm{sup 2} based on the end of 6th fuel cycle and it was predicted that the fluences of vessel inside surface at 16 and 32EFPY would reach 9.249E 18 and 1.834E 19n/cm{sup 2} based on the current calculation. The result through this analysis for Ulchin unit 3 showed that there would be no problem for the pressurized thermal shock(PTS) during the operation until design life.

  19. Geared-elevator flutter study. [transonic flutter characteristics of empennage

    Science.gov (United States)

    Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.

    1976-01-01

    The paper describes an experimental and analytical study of the transonic flutter characteristics of an empennage flutter model having an all-movable horizontal tail with a geared elevator. Two configurations were flutter tested: one with a geared elevator and one with a locked elevator with the model cantilever-mounted on a sting in the wind tunnel. The geared-elevator configuration fluttered experimentally at about 20% higher dynamic pressures than the locked-elevator configuration. The experimental flutter boundary was nearly flat at transonic speeds for both configurations. It was found that an analysis which treated the elevator as a discrete surface predicted flutter dynamic pressure levels better than analyses which treated the stabilizer and elevator as a warped surface. Warped-surface methods, however, predicted more closely the experimental flutter frequencies and Mach number trends.

  20. Dispersal limitation does not control high elevational distribution of alien plant species in the southern Sierra Nevada, California

    Science.gov (United States)

    Rundel, Philip W.; Keeley, Jon E.

    2016-01-01

    Patterns of elevational distribution of alien plant species in the southern Sierra Nevada of California were used to test the hypothesis that alien plant species invading high elevations around the world are typically climate generalists capable of growing across a wide elevational range. The Sierra Nevada has been heavily impacted for more than a century and a half, first by heavy grazing up into high elevation meadows, followed by major logging, and finally, by impacts associated with recreational use. The comparative elevational patterns of distribution and growth form were compared for native and alien plant species in the four families (Asteraceae, Brassicaceae, Fabaceae, and Poaceae) that contribute the majority of naturalized aliens in the study area. The distribution of realized climatic niche breadth, as measured by elevational range of occurrence, was virtually identical for alien and native species, with both groups showing a roughly Gaussian distribution peaking with species whose range covers a span of 1500–1999 m. In contrast to alien species, which only rarely occurred at higher elevations, native species showed a distribution of upper elevation limits peaking at 3000–3499 m, an elevation that corresponds to the zone of upper montane and subalpine forests. Consistent with a hypothesis of abiotic limitations, only a few alien species have been ecologically successful invaders at subalpine and alpine elevations above 2500 m. The low diversity of aliens able to become established in these habitats is unlikely due to dispersal limitations, given the long history of heavy grazing pressure at high elevations across this region. Instead, this low diversity is hypothesized to be a function of life history traits and multiple abiotic stresses that include extremes of cold air and soil temperature, heavy snowfall, short growing seasons, and low resource availability. These findings have significant implications for resource managers.