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Sample records for filling pressure assessed

  1. Left atrial strain: a new parameter for assessment of left ventricular filling pressure.

    Science.gov (United States)

    Cameli, Matteo; Mandoli, Giulia Elena; Loiacono, Ferdinando; Dini, Frank Lloyd; Henein, Michael; Mondillo, Sergio

    2016-01-01

    In order to obtain accurate diagnosis, treatment and prognostication in many cardiac conditions, there is a need for assessment of left ventricular (LV) filling pressure. While systole depends on ejection function of LV, diastole and its disturbances influence filling function and pressures. The commonest condition that represents the latter is heart failure with preserved ejection fraction in which LV ejection is maintained, but diastole is disturbed and hence filling pressures are raised. Significant diastolic dysfunction results in raised LV end-diastolic pressure, mean left atrial (LA) pressure and pulmonary capillary wedge pressure, all referred to as LV filling pressures. Left and right heart catheterization has traditionally been used as the gold standard investigation for assessing these pressures. More recently, Doppler echocardiography has taken over such application because of its noninvasive nature and for being patient friendly. A number of indices are used to achieve accurate assessment of filling pressures including: LV pulsed-wave filling velocities (E/A ratio, E wave deceleration time), pulmonary venous flow (S wave and D wave), tissue Doppler imaging (E' wave and E/E' ratio) and LA volume index. LA longitudinal strain derived from speckle tracking echocardiography (STE) is also sensitive in estimating intracavitary pressures. It is angle-independent, thus overcomes Doppler limitations and provides highly reproducible measures of LA deformation. This review examines the application of various Doppler echocardiographic techniques in assessing LV filling pressures, in particular the emerging role of STE in assessing LA pressures in various conditions, e.g., HF, arterial hypertension and atrial fibrillation.

  2. [Implantable sensors for outpatient assessment of ventricular filling pressure in advanced heart failure : Which telemonitoring design is optimal?

    Science.gov (United States)

    Herrmann, E; Fichtlscherer, S; Hohnloser, S H; Zeiher, A M; Aßmus, B

    2016-12-01

    Patients with advanced heart failure suffer from frequent hospitalizations. Non-invasive hemodynamic telemonitoring for assessment of ventricular filling pressure has been shown to reduce hospitalizations. We report on the right ventricular (RVP), the pulmonary artery (PAP) and the left atrial pressure (LAP) sensor for non-invasive assessment of the ventricular filling pressure. A literature search concerning the available implantable pressure sensors for noninvasive haemodynamic telemonitoring in patients with advanced heart failure was performed. Until now, only implantation of the PAP-sensor was able to reduce hospitalizations for cardiac decompensation and to improve quality of life. The right ventricular pressure sensor missed the primary endpoint of a significant reduction of hospitalizations, clinical data using the left atrial pressure sensor are still pending. The implantation of a pressure sensor for assessment of pulmonary artery filling pressure is suitable for reducing hospitalizations for heart failure and for improving quality of life in patients with advanced heart failure.

  3. Under Pressure: Intraluminal Filling Pressures of Postpartum Hemorrhage Tamponade Balloons.

    Science.gov (United States)

    Antony, Kathleen M; Racusin, Diana A; Belfort, Michael A; Dildy, Gary A

    2017-04-01

    Objective Uterine tamponade by fluid-filled balloons is now an accepted method of controlling postpartum hemorrhage. Available tamponade balloons vary in design and material, which affects the filling attributes and volume at which they rupture. We aimed to characterize the filling capacity and pressure-volume relationship of various tamponade balloons. Study Design Balloons were filled with water ex vivo. Intraluminal pressure was measured incrementally (every 10 mL for the Foley balloons and every 50 mL for all other balloons). Balloons were filled until they ruptured or until 5,000 mL was reached. Results The Foley balloons had higher intraluminal pressures than the larger-volume balloons. The intraluminal pressure of the Sengstaken-Blakemore tube (gastric balloon) was initially high, but it decreased until shortly before rupture occurred. The Bakri intraluminal pressure steadily increased until rupture occurred at 2,850 mL. The condom catheter, BT-Cath, and ebb all had low intraluminal pressures. Both the BT-Cath and the ebb remained unruptured at 5,000 mL. Conclusion In the setting of acute hemorrhage, expeditious management is critical. Balloons that have a low intraluminal pressure-volume ratio may fill more rapidly, more easily, and to greater volumes. We found that the BT-Cath, the ebb, and the condom catheter all had low intraluminal pressures throughout filling.

  4. Abnormal early diastolic intraventricular flow 'kinetic energy index' assessed by vector flow mapping in patients with elevated filling pressure.

    Science.gov (United States)

    Nogami, Yoshie; Ishizu, Tomoko; Atsumi, Akiko; Yamamoto, Masayoshi; Kawamura, Ryo; Seo, Yoshihiro; Aonuma, Kazutaka

    2013-03-01

    Recently developed vector flow mapping (VFM) enables evaluation of local flow dynamics without angle dependency. This study used VFM to evaluate quantitatively the index of intraventricular haemodynamic kinetic energy in patients with left ventricular (LV) diastolic dysfunction and to compare those with normal subjects. We studied 25 patients with estimated high left atrial (LA) pressure (pseudonormal: PN group) and 36 normal subjects (control group). Left ventricle was divided into basal, mid, and apical segments. Intraventricular haemodynamic energy was evaluated in the dimension of speed, and it was defined as the kinetic energy index. We calculated this index and created time-energy index curves. The time interval from electrocardiogram (ECG) R wave to peak index was measured, and time differences of the peak index between basal and other segments were defined as ΔT-mid and ΔT-apex. In both groups, early diastolic peak kinetic energy index in mid and apical segments was significantly lower than that in the basal segment. Time to peak index did not differ in apex, mid, and basal segments in the control group but was significantly longer in the apex than that in the basal segment in the PN group. ΔT-mid and ΔT-apex were significantly larger in the PN group than the control group. Multiple regression analysis showed sphericity index, E/E' to be significant independent variables determining ΔT apex. Retarded apical kinetic energy fluid dynamics were detected using VFM and were closely associated with LV spherical remodelling in patients with high LA pressure.

  5. Rationale, design and methodology for Intraventricular Pressure Gradients Study: a novel approach for ventricular filling assessment in normal and falling hearts

    Directory of Open Access Journals (Sweden)

    Vouga Luís

    2011-05-01

    Full Text Available Abstract Background Intraventricular pressure gradients have been described between the base and the apex of the left ventricle during early diastolic ventricular filling, as well as, their increase after systolic and diastolic function improvement. Although, systolic gradients have also been observed, data are lacking on their magnitude and modulation during cardiac dysfunction. Furthermore, we know that segmental dysfunction interferes with the normal sequence of regional contraction and might be expected to alter the physiological intraventricular pressure gradients. The study hypothesis is that systolic and diastolic gradients, a marker of normal left ventricular function, may be related to physiological asynchrony between basal and apical myocardial segments and they can be attenuated, lost entirely, or even reversed when ventricular filling/emptying is impaired by regional acute ischemia or severe aortic stenosis. Methods/Design Animal Studies: Six rabbits will be completely instrumented to measuring apex to outflow-tract pressure gradient and apical and basal myocardial segments lengthening changes at basal, afterloaded and ischemic conditions. Afterload increase will be performed by abruptly narrowing or occluding the ascending aorta during the diastole and myocardial ischemia will be induced by left coronary artery ligation, after the first diagonal branch. Patient Studies: Patients between 65-80 years old (n = 12, both genders, with severe aortic stenosis referred for aortic valve replacement will be selected as eligible subjects. A high-fidelity pressure-volume catheter will be positioned through the ascending aorta across the aortic valve to measure apical and outflow-tract pressure before and after aortic valve replacement with a bioprosthesis. Peak and average intraventricular pressure gradients will be recorded as apical minus outflow-tract pressure and calculated during all diastolic and systolic phases of cardiac cycle

  6. Noninvasive assessment of filling pressure and left atrial pressure overload in severe aortic valve stenosis: relation to ventricular remodeling and clinical outcome after aortic valve replacement

    DEFF Research Database (Denmark)

    Dahl, Jordi S; Videbæk, Lars; Poulsen, Mikael K

    2011-01-01

    One of the hemodynamic consequences of aortic valve stenosis is pressure overload leading to left atrial dilatation. Left atrial size is a known risk factor providing prognostic information in several cardiac conditions. It is not known if this is also the case in patients with aortic valve...

  7. Ram accelerator operating characteristics at elevated fill pressures

    Energy Technology Data Exchange (ETDEWEB)

    Bundy, C.; Knowlen, C.; Bruckner, A.P. [Washington Univ., Seattle, WA (United States). Aerospace and Energetics Research Program

    2000-11-01

    An experimental investigation of the starting and operational characteristics of a 38-mm bore ram accelerator with propellant fill pressures greater than 5 MPa is in progress. Successful starts with 60 - 124 gm projectiles have been achieved using methane/oxygen/nitrogen propellants at fill pressures ranging from 6 to 15 MPa. At fill pressures of 8.5 MPa and above, it was found that projectiles having the nominal throat diameter (29 mm) required a minimum entrance velocity of 1250 m/s, which is about 100 m/s faster than the minimum needed to successfully start the ram accelerator at fill pressures below 7.5 MPa. Projectiles with a reduced throat diameter (25 mm) and a solid magnesium nose cone were successfully started at fill pressures up to 15 MPa with entrance velocities around 1300 m/s. The average accelerations achieved using high pressure stages were in general less than predicted for thermally choked operation by the Boltzmann equation of state. (orig.)

  8. Mean systemic filling pressure : from Guyton to the ICU

    NARCIS (Netherlands)

    Maas, Jacomina Johanna (Jacinta)

    2013-01-01

    Mean systemic filling pressure (Pmsf)is defined as the pressure in the blood vessels during cardiac arrest. Pmsf is an important determinant for venous return to the heart and thus for cardiac output. This thesis describes a method to measure Pmsf at the bedside in intensive care patients and

  9. Mean systemic filling pressure : from Guyton to the ICU

    NARCIS (Netherlands)

    Maas, Jacomina Johanna (Jacinta)

    2013-01-01

    Mean systemic filling pressure (Pmsf)is defined as the pressure in the blood vessels during cardiac arrest. Pmsf is an important determinant for venous return to the heart and thus for cardiac output. This thesis describes a method to measure Pmsf at the bedside in intensive care patients and descri

  10. Fluid-filled blood pressure measurement systems.

    Science.gov (United States)

    Li, J K; van Brummelen, A G; Noordergraaf, A

    1976-05-01

    The performance of catheter-manometer systems for the measurement of pulsatile pressure has been evaluated by both experimental techniques and theoretical considerations. The former approach has shown, on occasion, multiple maxima in the amplitude response. The latter has been approached in a variety of ways, ranging from extreme lumping to application of transmission line theory while employing different configurations in the system's representation. Multiple maxima have also been seen, The present paper identifies the sources of the differences found and compares the relative merits of various theoretical approaches. It introduces the compliance of the system as a figure of merit and provides a simple first-order approximation formula for evaluation of the quality of a system. Damping and impedance matching to improve the system's frequency response were studied. It was found that they were not needed in a very stiff or a very compliant system, nor should one worry about the representation of such a system.

  11. Correlation Between Endotracheal Tube Cuff Pressure and Tracheal Wall Pressure Using Air and Saline Filled Cuffs

    Science.gov (United States)

    2017-01-31

    AFRL-SA-WP-SR-2017-0004 Correlation Between Endotracheal Tube Cuff Pressure and Tracheal Wall Pressure Using Air - and Saline-Filled... Air Force Research Laboratory 711th Human Performance Wing U.S. Air Force School of Aerospace Medicine Aeromedical Research Department 2510 Fifth...Correlation Between Endotracheal Tube Cuff Pressure and Tracheal Wall Pressure Using Air - and Saline-Filled Cuffs 5a. CONTRACT NUMBER FA8650-14

  12. Systems and methods for regulating pressure of a filled-in gas

    Energy Technology Data Exchange (ETDEWEB)

    Stautner, Ernst Wolfgang; Michael, Joseph Darryl

    2016-05-03

    A system for regulating a pressure of a filled-in gas is presented. The system includes a reservoir that stores a reservoir gas adsorbed in a sorbent material at a storage temperature, a gas-filled tube containing the filled-in gas, a controller configured to determine a pressure change required in the filled-in gas based upon signals representative of a pressure of the filled-in gas inside the gas-filled tube and a required pressure threshold, determine an updated temperature of the sorbent material based upon the pressure change required in the filled-in gas, and regulate the pressure of the filled-in gas by controlling the reservoir to change the storage temperature of the sorbent material to reach the updated temperature of the sorbent material.

  13. Simultaneous in vivo comparison of water-filled and air-filled pressure measurement catheters: Implications for good urodynamic practice.

    Science.gov (United States)

    Gammie, A; Abrams, P; Bevan, W; Ellis-Jones, J; Gray, J; Hassine, A; Williams, J; Hashim, H

    2016-11-01

    This study aimed to evaluate whether the pressure readings obtained from air-filled catheters (AFCs) are the same as the readings from simultaneously inserted water-filled catheters (WFCs). It also aimed to make any possible recommendations for the use of AFCs to conform to International Continence Society (ICS) Good Urodynamic Practices (GUP). Female patients undergoing urodynamic studies in a single center had water-filled and air-filled catheters simultaneously measuring abdominal and intravesical pressure during filling with saline and during voiding. The pressures recorded by each system at each event during the test were compared using paired t-test and Bland-Altman analyses. 62 patients were recruited, of whom 51 had pressures that could be compared during filling, and 23 during voiding. On average, the pressures measured by the two systems were not significantly different during filling and at maximum flow, but the values for a given patient were found to differ by up to 10 cmH2 O. This study shows that AFCs and WFCs cannot be assumed to register equal values of pressure. It has further shown that even when the pdet readings are compared with their value at the start of a test, a divergence of values of up to 10 cmH2 O remains. If AFCs are used, care must be taken to compensate for any pdet variations that occur during patient movement. Before AFCs are adopted, new normal values for resting pressures need to be developed to allow good quality AFC pressure readings to be made. Neurourol. Urodynam. 35:926-933, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  14. Relationships Between Biomarkers and Left Ventricular Filling Pressures at Rest and During Exercise in Patients After Myocardial Infarction

    DEFF Research Database (Denmark)

    Andersen, Mads J; Ersbøll, Mads; Bro-Jeppesen, John

    2014-01-01

    BACKGROUND: Increased pulmonary capillary wedge pressure (PCWP) is an independent prognostic predictor after myocardial infarction (MI), but PCWP is difficult to assess noninvasively in subjects with preserved ejection fraction (EF). We hypothesized that biomarkers would provide information regar...... levels of natriuretic peptides, particularly MR-proANP, are associated with filling pressures at rest and during exercise....

  15. Characteristics of mold filling and entrainment of oxide film in low pressure casting of A356 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shan-Guang; Cao, Fu-Yang; Zhao, Xin-Yi; Jia, Yan-Dong; Ning, Zhi-Liang; Sun, Jian-Fei, E-mail: jfsun_hit@263.net

    2015-02-25

    The effect of pressurizing speed of low pressure casting on mold filling and mechanical properties of A356 alloy was studied. The mold filling behavior was calculated by two phase flow model using VOF (Volume of Fluid) method. In order to evaluate the accuracy of simulated results, the real mold filling process observed by X-ray radiography was compared. The results show that during mold filling the gate velocity first increased dramatically, then kept unchanged under relatively low pressurizing speed, or increased slowly under relatively high pressurizing speed. High gate velocity causes melt falling back under gravity with high speed. The falling velocity and the resultant relative rotating vortex are the main causes of oxide film entrainment in low pressure casting. The mechanical properties of the as-cast A356 alloy were measured by four-point bend test. Weibull probability plots were used to assess the fracture mechanisms under different pressurizing speeds. The results obtained in this paper illuminate on designing suitable pressurizing speed for mold filling in low pressure casting.

  16. Investigating Liquid Leak from Pre-Filled Syringes upon Needle Shield Removal: Effect of Air Bubble Pressure.

    Science.gov (United States)

    Chan, Edwin; Maa, Yuh-Fun; Overcashier, David; Hsu, Chung C

    2011-01-01

    This study is to investigate the effect of headspace air pressure in pre-filled syringes on liquid leak (dripping) from the syringe needle upon needle shield removal. Drip tests to measure drip quantity were performed on syringes manually filled with 0.5 or 1.0 mL of various aqueous solutions. Parameters assessed included temperature (filling and test), bulk storage conditions (tank pressure and the type of the pressurized gas), solution composition (pure water, 0.9% sodium chloride, and a monoclonal antibody formulation), and testing procedures. A headspace pressure analyzer was used to verify the drip test method. Results suggested that leakage is indeed caused by headspace pressure increase, and the temperature effect (ideal gas expansion) is a major, but not the only, factor. The dissolved gases in the liquid bulk prior to or during filling may contribute to leakage, as these gases could be released into the headspace due to solubility changes (in response to test temperature and pressure conditions) and cause pressure increase. Needle shield removal procedures were found to cause dripping, but liquid composition played little role. Overall, paying attention to the processing history (pressure and temperature) of the liquid bulk is the key to minimize leakage. The headspace pressure could be reduced by decreasing liquid bulk storage pressure, filling at a higher temperature, or employing lower solubility gas (e.g., helium) for bulk transfer and storage. Leakage could also be mitigated by simply holding the syringe needle pointing upward during needle shield removal. Substantial advances in pre-filled syringe technology development, particularly in syringe filling accuracy, have been made. However, there are factors, as subtle as how the needle shield (or tip cap) is removed, that may affect dosing accuracy. We recently found that upon removal of the tip cap from a syringe held vertically with needle pointed downwards, a small amount of solution, up to 3-4% of

  17. Optimization of die filling in high pressure die cast part using MAGMAsoft®

    DEFF Research Database (Denmark)

    Kotas, Petr; Hattel, Jesper Henri

    2008-01-01

    using the commercial software code MAGMAsoft®. The first process analysis revealed problems and defects of the casting which were cold shuts and out-of plane distortions. Secondly adjustment in the geometry of the casting and the gating system were carried out and evaluated. Last, modifications...... in the process and machine parameters were done and assessed. All simulations revealed that, the main causes of the problems were: a poor geometry of the casting leading to an improper filling pattern, and a massive gating system bringing thermal imbalance into the solidification process. Thus deformations due......Integrated modeling of an entire casting process has become a tool which favors design and optimization of manufactured parts. The aim of this project was to examine and optimize a high-pressure die cast part and its production process with respect to die filling and issues of residual stresses...

  18. Models of venous return and their application to estimate the mean systemic filling pressure

    NARCIS (Netherlands)

    Hartog, E.A. den

    2007-01-01

    Mean systemic filling pressure is the equilibrium pressure in the systemic circulation when the heart is arrested and there is no flow. This pressure is a measure of the stressed volume of the systemic circulation and regarded as the driving pressure for the venous return during steady states [1-3].

  19. Models of venous return and their application to estimate the mean systemic filling pressure

    NARCIS (Netherlands)

    E.A. den Hartog (Emiel)

    1997-01-01

    textabstractMean systemic filling pressure is the equilibrium pressure in the systemic circulation when the heart is arrested and there is no flow. This pressure is a measure of the stressed volume of the systemic circulation and regarded as the driving pressure for the venous return during steady s

  20. Models of venous return and their application to estimate the mean systemic filling pressure

    NARCIS (Netherlands)

    E.A. den Hartog (Emiel)

    1997-01-01

    textabstractMean systemic filling pressure is the equilibrium pressure in the systemic circulation when the heart is arrested and there is no flow. This pressure is a measure of the stressed volume of the systemic circulation and regarded as the driving pressure for the venous return during steady

  1. Models of venous return and their application to estimate the mean systemic filling pressure

    NARCIS (Netherlands)

    Hartog, E.A. den

    2007-01-01

    Mean systemic filling pressure is the equilibrium pressure in the systemic circulation when the heart is arrested and there is no flow. This pressure is a measure of the stressed volume of the systemic circulation and regarded as the driving pressure for the venous return during steady states [1-3].

  2. Models of venous return and their application to estimate the mean systemic filling pressure

    NARCIS (Netherlands)

    E.A. den Hartog (Emiel)

    1997-01-01

    textabstractMean systemic filling pressure is the equilibrium pressure in the systemic circulation when the heart is arrested and there is no flow. This pressure is a measure of the stressed volume of the systemic circulation and regarded as the driving pressure for the venous return during steady s

  3. Thermoelectric properties of high pressure synthesized lithium and calcium double-filled CoSb3

    Directory of Open Access Journals (Sweden)

    Xiaohui Li

    2017-01-01

    Full Text Available Lithium and calcium are inefficient filling elements of CoSb3 at ambient pressure, but show nice filling behavior under high pressure. In this work, we synthesized Li/Ca double-filled CoSb3 with high pressure synthesis method. The products show the skutterudite structure of Im3¯ symmetry. Thermoelectric properties were effectively enhanced through Li and Ca co-filling. For the optimal Li0.08Ca0.18Co4Sb12 sample, the power factor maintains a relatively high value over the whole measurement temperature range and peaks at 4700μWm−1K−2, meanwhile the lattice thermal conductivity is greatly suppressed, leading to a maximal ZT of 1.18 at 700 K. Current work demonstrates high pressure synthesis as an effective method to produce multiple elemental filled CoSb3 skutterudites.

  4. The Influence of Unidirectional Pressure on Electrical Conductivity of Carbon Black Filled Polyethylene

    Institute of Scientific and Technical Information of China (English)

    WANG Ke; ZHANG Guo; ZHAO Zhudi; PENG Yi; DI Weihua; DU Chuang

    2006-01-01

    High density polyethylene filled with conductive carbon black was prepared by conventional melt-mixing method. The effect of unidirectional pressure on the conductivity was studied. Wide angle X-ray diffraction (WAXD) was used to show the influence of pressure on the aggregate structure of the polymer filled with carbon black (CB) fillers. A model on the basis of the formation and destruction of conductive networks was proposed to explain the change in the conductivity with the application of pressure.

  5. Abrasion properties of homogenous and blended fill materials during pressure hydraulic transport

    Energy Technology Data Exchange (ETDEWEB)

    Turchaninov, S.P.

    1978-03-01

    A description is given of tests conducted to determine the abrasive properties of small and large-grain free-flowing fill materials during hydraulic transport of the materials under pressure. Data are given on the size, density, abrasiveness of various sized varieties of rock, sand, and blends comprising homogenous materials, simple and complex mixtures, and on the physical characteristics of various fill materials in relation to the trafficability and parameters of pipelines. Technical specifications are given for fill steel pipes. The study indicates that the durability of hydraulic fill pipelines largely depends on the abrasiveness of the fill materials. 3 references, 2 figures, 2 tables.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-15

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

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

    Directory of Open Access Journals (Sweden)

    Simone Nascimento dos Santos

    2014-12-01

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

  8. Measurement of pleural pressure swings with a fluid-filled esophageal catheter vs pulmonary artery occlusion pressure.

    Science.gov (United States)

    Verscheure, S; Massion, P B; Gottfried, S; Goldberg, P; Samy, L; Damas, P; Magder, S

    2017-02-01

    Pleural pressure measured with esophageal balloon catheters (Peso) can guide ventilator management and help with the interpretation of hemodynamic measurements, but these catheters are not readily available or easy to use. We tested the utility of an inexpensive, fluid-filled esophageal catheter (Peso) by comparing respiratory-induced changes in pulmonary artery occlusion (Ppao), central venous (CVP), and Peso pressures. We studied 30 patients undergoing elective cardiac surgery who had pulmonary artery and esophageal catheters in place. Proper placement was confirmed by chest compression with airway occlusion. Measurements were made during pressure-regulated volume control (VC) and pressure support (PS) ventilation. The fluid-filled esophageal catheter provided a high-quality signal. During VC and PS, change in Ppao (∆Ppao) was greater than ∆Peso (bias = -2 mm Hg) indicating an inspiratory increase in cardiac filling. During VC, ∆CVP bias was 0 indicating no change in right heart filling, but during PS, CVP fell less than Peso indicating an inspiratory increase in filling. Peso measurements detected activation of expiratory muscles, development of non-west zone 3 lung conditions during inspiration, and ventilator-triggered inspiratory efforts. A fluid-filled esophageal catheter provides a high-quality, easily accessible, and inexpensive measure of change in pleural pressure and provided insights into patient-ventilator interactions. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Circulatory filling pressures during transient microgravity induced by parabolic flight

    Science.gov (United States)

    Latham, Ricky D.; Fanton, John W.; White, C. D.; Vernalis, Mariana N.; Crisman, R. P.; Koenig, S. C.

    1993-01-01

    Theoretical concepts hold that blood in the gravity dependent portion of the body would relocate to more cephalad compartments under microgravity. The result is an increase in blood volume in the thoraic and cardiac chambers. However, experimental data has been somewhat contradictory and nonconclusive. Early studies of peripheral venous pressure and estimates of central venous pressure (CVP) from these data did not show an increase in CVP under microgravity. However, CVP recorded in human volunteers during a parabolic flight revealed an increase in CVP during the microgravity state. On the STS 40 shuttle mission, a payload specialist wore a fluid line that recorded CVP during the first few hours of orbital insertion. These data revealed decreased CVP. When this CVP catheter was tested during parabolic flight in four subjects, two had increased CVP recordings and two had decreased CVP measurements. In 1991, our laboratory performed parabolic flight studies in several chronic-instrumented baboons. It was again noted that centrally recorded right atrial pressure varied with exposure to microgravity, some animals having an increase, and others a decrease.

  10. Dependency of blood pressure upon cardiac filling in patients with severe postural hypotension

    DEFF Research Database (Denmark)

    Mehlsen, J; Haedersdal, C; Stokholm, K H

    1994-01-01

    Autonomic denervation of the vascular bed results theoretically in a stronger dependency of blood pressure upon intravascular volume, and the study described aimed at an investigation of the relation between cardiac filling and arterial blood pressure in patients with severe postural hypotension...... by vasoconstriction. The reduction in cardiac output resulted from reductions in left ventricular end-diastolic volumes with unchanged left ventricular ejection fractions and only moderate increments in heart rate. The study was demonstrated that blood pressure is strongly dependent upon cardiac filling in severe...

  11. Failure Mode of the Water-filled Fractures under Hydraulic Pressure in Karst Tunnels

    Science.gov (United States)

    Dong, Xin; Lu, Hao; Huang, Houxu; Hao, Yiqing; Xia, Yuanpu

    2017-06-01

    Water-filled fractures continue to grow after the excavation of karst tunnels, and the hydraulic pressure in these fractures changes along with such growth. This paper simplifies the fractures in the surrounding rock as flat ellipses and then identifies the critical hydraulic pressure values required for the occurrence of tensile-shear and compression-shear failures in water-filled fractures in the case of plane stress. The occurrence of tensile-shear fracture requires a larger critical hydraulic pressure than compression-shear failure in the same fracture. This paper examines the effects of fracture strike and lateral pressure coefficient on critical hydraulic pressure, and identifies compression-shear failure as the main failure mode of water-filled fractures. This paper also analyses the hydraulic pressure distribution in fractures with different extensions, and reveals that hydraulic pressure decreases along with the continuous growth of fractures and cannot completely fill a newly formed fracture with water. Fracture growth may be interrupted under the effect of hydraulic tensile shear.

  12. Failure Mode of the Water-filled Fractures under Hydraulic Pressure in Karst Tunnels

    Directory of Open Access Journals (Sweden)

    Dong Xin

    2017-06-01

    Full Text Available Water-filled fractures continue to grow after the excavation of karst tunnels, and the hydraulic pressure in these fractures changes along with such growth. This paper simplifies the fractures in the surrounding rock as flat ellipses and then identifies the critical hydraulic pressure values required for the occurrence of tensile-shear and compression-shear failures in water-filled fractures in the case of plane stress. The occurrence of tensile-shear fracture requires a larger critical hydraulic pressure than compression-shear failure in the same fracture. This paper examines the effects of fracture strike and lateral pressure coefficient on critical hydraulic pressure, and identifies compression-shear failure as the main failure mode of water-filled fractures. This paper also analyses the hydraulic pressure distribution in fractures with different extensions, and reveals that hydraulic pressure decreases along with the continuous growth of fractures and cannot completely fill a newly formed fracture with water. Fracture growth may be interrupted under the effect of hydraulic tensile shear.

  13. Factors affecting opening and filling pressures in the lungs of the lizard Pogona vitticeps.

    Science.gov (United States)

    Wood, P G; Daniels, C B

    1996-02-01

    We have previously reported that levels of pulmonary surfactant in the lungs of the lizard Pogona vitticeps increase with increasing body temperature. Static lung compliance decreases with increasing body temperature, and is only marginally affected by the presence of surfactant. Here, we examined the effects of surfactant, temperature, ventilatory pattern and autonomic neurotransmitters on opening and filling pressures. Isolated lungs were ventilated at either 18 or 37 degrees C at low, intermediate and high ventilatory regimes. The effects of acetylcholine and adrenaline were examined using an isolated perfused lung preparation at 27 degrees C. Changing ventilatory pattern or experimental temperature had no effect on either filling or opening pressures. Removal of surfactant increased both opening and filling pressures. Adrenaline administration reduced opening and filling pressures. Normal variations in surfactant levels, which occur with changes in body temperature, do not affect either opening or filling pressures. A critical amount of surfactant may be necessary to prevent adhesion of epithelial surfaces in the lungs of Pogona vitticeps. The anti-glue function of pulmonary surfactant may be more important at 18 than at 37 degrees C.

  14. Numerical simulation of mould filling process for pressure plate and valve handle in LFC

    Directory of Open Access Journals (Sweden)

    Jiang Junxia

    2010-11-01

    Full Text Available In lost foam casting (LFC, the distribution of polymer beads during the bead filling process is not uniform, and the collision between polymer beads determines the distribution of two-phase flow of gas and solid. The interaction between the gas and solid phases reveals as coupling effect of the force that gas exerts on particles or vice versa, or that among particles. The gas-solid flow in filling process is nonlinearity, which makes the coupling effect an essential point to carry out a simulation properly. Therefore, information of each particle’s motion is important for acquiring the law of filling process. In bead filling process, compressed air is pressed into mold cavity, and discharged from gas vent, creating a pressure difference between outer and inner space near the gas vent. This pressure difference directly changes the spatial distribution and motion trace of gas and solid phases. In this paper, Discrete Element Method (DEM and Computational Fluid Dynamics (CFD are employed to simulate the fluid dynamic character based on Newton’s Third Law of Motion. The simulation results of some casting products such as pressure plate and valve handle are compared with the result obtained from practical experiment in order to test the feasibility of DEM. The comparison shows that this DEM method can be a very promising tool in the mould filling simulation of beads’ movement.

  15. Conversion of urodynamic pressures measured simultaneously by air-charged and water-filled catheter systems.

    Science.gov (United States)

    Awada, Hassan K; Fletter, Paul C; Zaszczurynski, Paul J; Cooper, Mitchell A; Damaser, Margot S

    2015-08-01

    The objective of this study was to compare the simultaneous responses of water-filled (WFC) and air-charged (ACC) catheters during simulated urodynamic pressures and develop an algorithm to convert peak pressures measured using an ACC to those measured by a WFC. Examples of cough leak point pressure and valsalva leak point pressure data (n = 4) were obtained from the literature, digitized, and modified in amplitude and duration to create a set of simulated data that ranged in amplitude from 15 to 220 cm H2 O (n = 25) and duration from 0.1 to 3.0 sec (n = 25) for each original signal. Simulated pressure signals were recorded simultaneously by WFCs, ACCs, and a reference transducer in a specially designed pressure chamber. Peak pressure and time to peak pressure were calculated for each simulated pressure signal and were used to develop an algorithm to convert peak pressures recorded with ACCs to corresponding peak pressures recorded with WFCs. The algorithm was validated with additional simulated urodynamic pressure signals and additional catheters that had not been utilized to develop the algorithm. ACCs significantly underestimated peak pressures of more rapidly changing pressures, as in coughs, compared to those measured by WFCs. The algorithm corrected 90% of peak pressures measured by ACCs to within 5% of those measured by WFCs when simultaneously exposed to the same pressure signals. The developed algorithm can be used to convert rapidly changing urodynamic pressures, such as cough leak point pressure, obtained using ACC systems to corresponding values expected from WFC systems. © 2014 Wiley Periodicals, Inc.

  16. Effect of surfactants on pressure-sensitivity of CNT filled cement mortar composites

    Science.gov (United States)

    Han, Baoguo; Yu, Xun

    2014-11-01

    Sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (NaDDBS) were used as surfactants to disperse multi-walled carbon nanotubes (MWNT) in cement mortar and fabricate pressure-sensitive carbon nanotubes filled cement mortar composites. The pressure-sensitivity of cement mortar composites with different concentrations of MWNT and different surfactants was explored under repeated loading and impulsive loading, respectively. Experimental results indicate that the response of the electrical resistance of composites with NaDDBS to external force is more stable and sensitive than that of composites with SDS. Therefore, NaDDBS has higher efficiency than SDS for the dispersion of MWNT in cement mortar, and it is an effective surfactant for fabricating MWNT filled cement mortar composites with superior pressure-sensitivity.

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

    Institute of Scientific and Technical Information of China (English)

    LuGuoyun; LeiJianping; ZhangShanyuan

    2004-01-01

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

  18. Intraventricular filling in physical models of the left ventricle: influence of aortic pressure

    Science.gov (United States)

    Nelsen, Nicholas; Samaee, Milad; Santhanakrishnan, Arvind

    2016-11-01

    Clinical studies using medical imaging have provided evidence on the formation of an intraventricular vortex in the left ventricle (LV) during diastolic phase of the cardiac cycle. However, the question of how the vortex characteristics are altered with aortic pressure remains unclear. This is of relevance to hypertensive heart disease and heart failure with normal ejection fraction. Using an experimental left heart simulator, we have previously shown that increasing LV wall stiffness results in reduction of the filling vortex circulation. In this study, we investigate the effects of varying aortic pressure in addition to wall stiffness. A series of flexible-walled LV models with varying wall stiffness were tested in a pulsatile flow loop. 2D particle image velocimetry was used to visualize intraventricular flow and calculate filling vortex circulation. The flow circuit was first setup with the least stiffness LV physical model, and tuned to physiological aortic pressure, cardiac output and ejection fraction. We then iteratively tested LV models with increasing stiffness without changing circuit variables. Comparisons of the filling vortex circulation with changing aortic pressure relative to the baseline and increased LV stiffness models will be presented.

  19. Hydrogen gas filling into an actual tank at high pressure and optimization of its thermal characteristics

    Science.gov (United States)

    Khan, Md. Tawhidul Islam; Monde, Masanori; Setoguchi, Toshiaki

    2009-09-01

    Gas with high pressure is widely used at present as fuel storage mode for different hydrogen vehicles. Different types of materials are used for constructing these hydrogen pressure vessels. An aluminum lined vessel and typically carbon fiber reinforced plastic (CFRP) materials are commercially used in hydrogen vessels. An aluminum lined vessel is easy to construct and posses high thermal conductivity compared to other commercially available vessels. However, compared to CFRP lined vessel, it has low strength capacity and safety factors. Therefore, nowadays, CFRP lined vessels are becoming more popular in hydrogen vehicles. Moreover, CFRP lined vessel has an advantage of light weight. CFRP, although, has many desirable properties in reducing the weight and in increasing the strength, it is also necessary to keep the material temperature below 85 °C for maintaining stringent safety requirements. While filling process occurs, the temperature can be exceeded due to the compression works of the gas flow. Therefore, it is very important to optimize the hydrogen filling system to avoid the crossing of the critical limit of the temperature rise. Computer-aided simulation has been conducted to characterize the hydrogen filling to optimize the technique. Three types of hydrogen vessels with different volumes have been analyzed for optimizing the charging characteristics of hydrogen to test vessels. Gas temperatures are measured inside representative vessels in the supply reservoirs (H2 storages) and at the inlet to the test tank during filling.

  20. Liquid-filled transient pressure measuring systems: A method for determining frequency response

    Science.gov (United States)

    Anderson, R. C.; Englund, D. R., Jr.

    1971-01-01

    An equation is given and experimentally verified for computing the resonant frequency of liquid-filled transient pressure measuring systems. Resonant frequencies of 100 to 1000 Hz are typical of those systems tested. The effect of noncondensable gas bubbles on system response is described. A method for determining transducer volumetric compliance is presented. An example system is described and analyzed to demonstrate the use of the theory.

  1. Assessment of periapical health, quality of root canal filling, and ...

    African Journals Online (AJOL)

    2015-12-03

    Dec 3, 2015 ... 2016 Nigerian Journal of Clinical Practice | Published by Wolters Kluwer - Medknow ... Inadequately dense root canal filling was observed in 141 teeth, whereas ... Conclusion: The results indicate that the quality of both the root filling and ... seeking implant applications and oral pathology diagnoses. Clinic ...

  2. Unexplained exertional dyspnea caused by low ventricular filling pressures: results from clinical invasive cardiopulmonary exercise testing

    Science.gov (United States)

    Lewis, Gregory D.; Opotowsky, Alexander R.; Waxman, Aaron B.; Systrom, David M.

    2016-01-01

    Abstract To determine whether low ventricular filling pressures are a clinically relevant etiology of unexplained dyspnea on exertion, a database of 619 consecutive, clinically indicated invasive cardiopulmonary exercise tests (iCPETs) was reviewed to identify patients with low maximum aerobic capacity (V̇o2max) due to inadequate peak cardiac output (Qtmax) with normal biventricular ejection fractions and without pulmonary hypertension (impaired: n = 49, V̇o2max = 53% predicted [interquartile range (IQR): 47%–64%], Qtmax = 72% predicted [62%–76%]). These were compared to patients with a normal exercise response (normal: n = 28, V̇o2max = 86% predicted [84%–97%], Qtmax = 108% predicted [97%–115%]). Before exercise, all patients received up to 2 L of intravenous normal saline to target an upright pulmonary capillary wedge pressure (PCWP) of ≥5 mmHg. Despite this treatment, biventricular filling pressures at peak exercise were lower in the impaired group than in the normal group (right atrial pressure [RAP]: 6 [IQR: 5–8] vs. 9 [7–10] mmHg, P = 0.004; PCWP: 12 [10–16] vs. 17 [14–19] mmHg, P < 0.001), associated with decreased stroke volume (SV) augmentation with exercise (+13 ± 10 [standard deviation (SD)] vs. +18 ± 10 mL/m2, P = 0.014). A review of hemodynamic data from 23 patients with low RAP on an initial iCPET who underwent a second iCPET after saline infusion (2.0 ± 0.5 L) demonstrated that 16 of 23 patients responded with increases in Qtmax ([+24% predicted [IQR: 14%–34%]), V̇o2max (+10% predicted [7%–12%]), and maximum SV (+26% ± 17% [SD]). These data suggest that inadequate ventricular filling related to low venous pressure is a clinically relevant cause of exercise intolerance. PMID:27162614

  3. Pressure wave propagation in fluid-filled co-axial elastic tubes. Part 1: Basic theory.

    Science.gov (United States)

    Berkouk, K; Carpenter, P W; Lucey, A D

    2003-12-01

    Our work is motivated by ideas about the pathogenesis of syringomyelia. This is a serious disease characterized by the appearance of longitudinal cavities within the spinal cord. Its causes are unknown, but pressure propagation is probably implicated. We have developed an inviscid theory for the propagation of pressure waves in co-axial, fluid-filled, elastic tubes. This is intended as a simple model of the intraspinal cerebrospinal-fluid system. Our approach is based on the classic theory for the propagation of longitudinal waves in single, fluid-filled, elastic tubes. We show that for small-amplitude waves the governing equations reduce to the classic wave equation. The wave speed is found to be a strong function of the ratio of the tubes' cross-sectional areas. It is found that the leading edge of a transmural pressure pulse tends to generate compressive waves with converging wave fronts. Consequently, the leading edge of the pressure pulse steepens to form a shock-like elastic jump. A weakly nonlinear theory is developed for such an elastic jump.

  4. Detecting leaks in gas-filled pressure vessels using acoustic resonances

    Science.gov (United States)

    Gillis, K. A.; Moldover, M. R.; Mehl, J. B.

    2016-05-01

    We demonstrate that a leak from a large, unthermostatted pressure vessel into ambient air can be detected an order of magnitude more effectively by measuring the time dependence of the ratio p/f2 than by measuring the ratio p/T. Here f is the resonance frequency of an acoustic mode of the gas inside the pressure vessel, p is the pressure of the gas, and T is the kelvin temperature measured at one point in the gas. In general, the resonance frequencies are determined by a mode-dependent, weighted average of the square of the speed-of-sound throughout the volume of the gas. However, the weighting usually has a weak dependence on likely temperature gradients in the gas inside a large pressure vessel. Using the ratio p/f2, we measured a gas leak (dM/dt)/M ≈ - 1.3 × 10-5 h-1 = - 0.11 yr-1 from a 300-liter pressure vessel filled with argon at 450 kPa that was exposed to sunshine-driven temperature and pressure fluctuations as large as (dT/dt)/T ≈ (dp/dt)/p ≈ 5 × 10-2 h-1 using a 24-hour data record. This leak could not be detected in a 72-hour record of p/T. (Here M is the mass of the gas in the vessel and t is the time.)

  5. Effect of pressurization on helical guided wave energy velocity in fluid-filled pipes.

    Science.gov (United States)

    Dubuc, Brennan; Ebrahimkhanlou, Arvin; Salamone, Salvatore

    2017-03-01

    The effect of pressurization stresses on helical guided waves in a thin-walled fluid-filled pipe is studied by modeling leaky Lamb waves in a stressed plate bordered by fluid. Fluid pressurization produces hoop and longitudinal stresses in a thin-walled pipe, which corresponds to biaxial in-plane stress in a plate waveguide model. The effect of stress on guided wave propagation is accounted for through nonlinear elasticity and finite deformation theory. Emphasis is placed on the stress dependence of the energy velocity of the guided wave modes. For this purpose, an expression for the energy velocity of leaky Lamb waves in a stressed plate is derived. Theoretical results are presented for the mode, frequency, and directional dependent variations in energy velocity with respect to stress. An experimental setup is designed for measuring variations in helical wave energy velocity in a thin-walled water-filled steel pipe at different levels of pressure. Good agreement is achieved between the experimental variations in energy velocity for the helical guided waves and the theoretical leaky Lamb wave solutions.

  6. Nonlinear optics in Xe-filled hollow-core PCF in high pressure and supercritical regimes

    CERN Document Server

    Azhar, M; Travers, J C; Russell, P St J

    2013-01-01

    Supercritical Xe at 293 K offers a Kerr nonlinearity that can exceed that of fused silica while being free of Raman scattering. It also has a much higher optical damage threshold and a transparency window that extends from the UV to the infrared. We report the observation of nonlinear phenomena, such as self-phase modulation, in hollow-core photonic crystal fiber filled with supercritical Xe. In the subcritical regime, intermodal four-wave-mixing resulted in the generation of UV light in the HE12 mode. The normal dispersion of the fiber at high pressures means that spectral broadening can clearly obtained without influence from soliton effects or material damage.

  7. High-pressure synthesis of the filled skutterudite PrFe 4Sb 12

    Science.gov (United States)

    Tanaka, Kenya; Kawahito, Yusuke; Kikuchi, Daisuke; Aoki, Hidekazu; Aoki, Yuji; Sato, Hideyuki

    2006-05-01

    We have succeeded in synthesizing the filled skutterudite PrFe 4Sb 12 crystals at high pressures and temperatures. To investigate bulk properties, we measured the magnetic susceptibility down to 2 K and electrical resistivity down to 0.7 K. The magnetic susceptibility exhibits a broad maximum around 10 K and follows the Curie Weiss law above ∼150 K with the effective magnetic moment of 4.5μB/f.u. The electrical resistivity increases with increasing temperature up to room temperature exhibiting tendencies to saturation at around 10 and 100 K. The relatively large residual resistivity ratio of ∼24 suggests high quality of the grown sample.

  8. Numerical Simulation of the Thermal Conductivity of Thermal Insulation Pipe by Vacuum and High Pressure Argon Pre-filled

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    [Abstract]By analyzing the insulation effect of argon-filled tubing and vacuum-insulated tubing before and after hydrogen permeation respectively, a conclusion can be drawn that the insulated tubing filled with high pressure argon is better than the vacuum insulated tubing considering the lifetime and heat insulation effect.

  9. Safety analysis of high pressure 3He-filled micro-channels for thermal neutron detection.

    Energy Technology Data Exchange (ETDEWEB)

    Ferko, Scott M.; Galambos, Paul C.; Derzon, Mark Steven; Renzi, Ronald F.

    2008-11-01

    This document is a safety analysis of a novel neutron detection technology developed by Sandia National Laboratories. This technology is comprised of devices with tiny channels containing high pressure {sup 3}He. These devices are further integrated into large scale neutron sensors. Modeling and preliminary device testing indicates that the time required to detect the presence of special nuclear materials may be reduced under optimal conditions by several orders of magnitude using this approach. Also, these devices make efficient use of our {sup 3}He supply by making individual devices more efficient and/or extending the our limited {sup 3}He supply. The safety of these high pressure devices has been a primary concern. We address these safety concerns for a flat panel configuration intended for thermal neutron detection. Ballistic impact tests using 3 g projectiles were performed on devices made from FR4, Silicon, and Parmax materials. In addition to impact testing, operational limits were determined by pressurizing the devices either to failure or until they unacceptably leaked. We found that (1) sympathetic or parasitic failure does not occur in pressurized FR4 devices (2) the Si devices exhibited benign brittle failure (sympathetic failure under pressure was not tested) and (3) the Parmax devices failed unacceptably. FR4 devices were filled to pressures up to 4000 + 100 psig, and the impacts were captured using a high speed camera. The brittle Si devices shattered, but were completely contained when wrapped in thin tape, while the ductile FR4 devices deformed only. Even at 4000 psi the energy density of the compressed gas appears to be insignificant compared to the impact caused by the incoming projectile. In conclusion, the current FR4 device design pressurized up to 4000 psi does not show evidence of sympathetic failure, and these devices are intrinsically safe.

  10. Experiments of draining and filling processes in a collapsible tube at high external pressure

    Science.gov (United States)

    Flaud, P.; Guesdon, P.; Fullana, J.-M.

    2012-02-01

    The venous circulation in the lower limb is mainly controlled by the muscular action of the calf. To study the mechanisms governing the venous draining and filling process in such a situation, an experimental setup, composed by a collapsible tube under external pressure, has been built. A valve preventing back flows is inserted at the bottom of the tube and allows to model two different configurations: physiological when the fluid flow is uni-directional and pathological when the fluid flows in both directions. Pressure and flow rate measurements are carried out at the inlet and outlet of the tube and an original optical device with three cameras is proposed to measure the instantaneous cross-sectional area. The experimental results (draining and filling with physiological or pathological valves) are confronted to a simple one-dimensional numerical model which completes the physical interpretation. One major observation is that the muscular contraction induces a fast emptying phase followed by a slow one controlled by viscous effects, and that a defect of the valve decreases, as expected, the ejected volume.

  11. Development of a 3D Filling Model of Low-Pressure Die-Cast Aluminum Alloy Wheels

    Science.gov (United States)

    Duan, Jianglan; Maijer, Daan; Cockcroft, Steve; Reilly, Carl

    2013-12-01

    A two-phase computational fluid dynamics model of the low-pressure die-cast process for the production of A356 aluminum alloy wheels has been developed to predict the flow conditions during die filling. The filling model represents a 36-deg section of a production wheel, and was developed within the commercial finite-volume package, ANSYS CFX, assuming isothermal conditions. To fully understand the behavior of the free surface, a novel technique was developed to approximate the vent resistances as they impact on the development of a backpressure within the die cavity. The filling model was first validated against experimental data, and then was used to investigate the effects of venting conditions and pressure curves during die filling. It was found that vent resistance and vent location strongly affected die filling time, free surface topography, and air entrainment for a given pressure fill-curve. With regard to the pressure curve, the model revealed a strong relation between the pressure curve and the flow behavior in the hub, which is an area prone to defect formation.

  12. Standard practice for examination of seamless, gas-filled, steel pressure vessels using angle beam ultrasonics

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice describes a contact angle-beam shear wave ultrasonic technique to detect and locate the circumferential position of longitudinally oriented discontinuities and to compare the amplitude of the indication from such discontinuities to that of a specified reference notch. This practice does not address examination of the vessel ends. The basic principles of contact angle-beam examination can be found in Practice E 587. Application to pipe and tubing, including the use of notches for standardization, is described in Practice E 213. 1.2 This practice is appropriate for the ultrasonic examination of cylindrical sections of gas-filled, seamless, steel pressure vessels such as those used for the storage and transportation of pressurized gasses. It is applicable to both isolated vessels and those in assemblies. 1.3 The practice is intended to be used following an Acoustic Emission (AE) examination of stacked seamless gaseous pressure vessels (with limited surface scanning area) described in Test Met...

  13. Expansion characteristics of twin combustion gas jets with high pressure in cylindrical filling liquid chamber

    Institute of Scientific and Technical Information of China (English)

    薛晓春; 余永刚; 张琦

    2013-01-01

    To deal with the problem of how to control the interior ballistic stability in the bulk-loaded liquid propellant gun, the expansion and mixing process of the twin combustion-gas jets with high temperature and pressure in a liquid medium is studied in the cylindrical filling liquid chamber. A series of the jet expansion shapes is obtained by using a high-speed photographic system. The influences of the jet pressure on the jet expansion shape are discussed. Based on the experiments, the three-dimensional mathematical model is established. The expansion processes of the twin gas jets in the liquid medium are simulated by means of fluent to get the pressure, density, temperature, velocity contours and evolutionary process of vortices. Results show that the jet external outline and tops are all irregular. The Kelvin-Helmholtz instability is shown in the whole expansion process. The numerical simulation results of the axial displacement of the twin gas jets in liquid agree well with the experiment.

  14. Spectral properties of molecular iodine absorption cells filled to saturation pressure

    Science.gov (United States)

    Hrabina, Jan; Sarbort, Martin; Cip, Ondrej; Lazar, Josef

    2014-05-01

    The absorption cells - optical frequencies references - represent the crucial part of setups for practical realization of the meter unit - highly stable laser standards, where varied laser sources are frequency locked to the selected absorption transitions. Furthermore, not only in the most precise laboratory instruments, but also in less demanding interferometric measuring setups the frequency stabilization of the lasers throught the absorption in suitable media ensure the direct traceability to the fundamental standard of length. We present the results of measurement and evaluation of spectral properties of molecular iodine absorption cells filled to saturation pressure of absorption media. A set of cells filled with different amounts of molecular iodine was prepared and an agreement between expected and resulting spectral properties of these cells was observed and evaluated. The cells made of borosilicate glass instead of common fused silica were tested for their spectral properties in greater detail with special care for the absorption media purity - the measured hyperfine transitions linewidths were compared to cells traditionally made of fused silica glass with well known iodine purity. The usage of borosilicate glass material represents easier manufacturing process and also significant costs reduction but a great care must be taken to control/avoid the risk of absorption media contamination. An approach relying on measurement of linewidth of the hyperfine transitions is proposed and discussed.

  15. Low-frequency pressure wave propagation in liquid-filled, flexible tubes. (A)

    DEFF Research Database (Denmark)

    Bjørnø, Leif; Bjelland, C.

    1992-01-01

    A model has been developed for propagation of low-frequency pressure waves in viscoelastic tubes with distensibility of greater importance than compressibility of the liquid. The dispersion and attenuation are shown to be strongly dependent on the viscoelastic properties of the tube wall....... The complex, frequency-dependent moduli of relevant tube materials have been measured in a series of experiments using three different experimental procedures, and the data obtained are compared. The three procedures were: (1) ultrasonic wave propagation, (2) transversal resonance in bar samples, and (3......) moduli determined by stress wave transfer function measurements in simple extension experiments. The moduli are used in the model to produce realistic dispersion relations and frequency dependent attenuation. Signal transfer functions between positions in the liquid-filled tube can be synthesized from...

  16. Transport properties of the filled skutterudite PrxFe4Sb12 synthesized under high pressure

    Science.gov (United States)

    Tanaka, Kenya; Kikuchi, Daisuke; Kawahito, Yusuke; Ueda, Makoto; Aoki, Hidekazu; Kuwahara, Keitaro; Sugawara, Hitoshi; Aoki, Yuji; Sato, Hideyuki

    2008-04-01

    We have investigated the thermoelectric power ( S), Hall coefficient ( RH), and magnetoresistance (MR) of PrxFe4Sb12 ( x∼1) synthesized under high pressure. The dependence of S and RH on the Pr-site filling fraction x become apparent at low temperatures. In MR, we confirmed that the electrical resistivity is enhanced by the 4f-electron crystalline electric field effect below ∼10 K and suppressed by the 3d-electron spin fluctuation effect above ∼10 K. The change of magnetic state in PrxFe4Sb12 with x, realized as a combined effect of 4f-electrons and the high electronic density of state at Fermi level, is well reflected in the transport properties.

  17. Sb NQR study of the filled skutterudite CeFe4Sb12 synthesized under high pressure

    Science.gov (United States)

    Magishi, Ko-ichi; Takahashi, Masahiro; Saito, Takahito; Koyama, Kuniyuki; Sugawara, Hitoshi; Saito, Takashi; Tatsuoka, Sho; Tanaka, Kenya; Sato, Hideyuki

    2013-08-01

    We report the results of Sb nuclear quadrupole resonance (NQR) measurements on the filled skutterudite CeFe4Sb12 synthesized under high pressure (HP) and compare them with those for the sample synthesized under ambient pressure (AP) to understand the influence of the Ce-site filling fraction. The NQR spectra for the HP sample are much sharper than those for the AP sample, suggesting that the Ce filling fraction is higher. Also, the nuclear spin-lattice relaxation rate 1/ T 1 follows an exponential decrease 1/ T 1 ∝ exp(-Δ/ k B T), with the gap being Δ/ k B = 270 K at temperatures above 100 K, which is larger than that for the AP sample. This result suggests that the c- f hybridization is enhanced by increasing the Ce-site filling fraction.

  18. Design of the liquefied natural gas (LNG) vehicle gas cylinder filling semi-physical simulation training and assessment system

    Science.gov (United States)

    Gao, Jie; Zheng, Jianrong; Zhao, Yinghui

    2017-08-01

    With the rapid development of LNG vehicle in China, the operator's training and assessment of the operating skills cannot operate on material objects, because of Vehicle Gas Cylinder's high pressure, flammable and explosive characteristics. LNG Vehicle Gas Cylinder's filling simulation system with semi-physical simulation technology presents the overall design and procedures of the simulation system, and elaborates the realization of the practical analog machine, data acquisition and control system and the computer software, and introduces the design process of equipment simulation model in detail. According to the designed assessment system of the Vehicle Gas Cylinder, it can obtain the operation on the actual cylinder filling and visual effects for the operator, and automatically record operation, the results of real operation with its software, and achieve the operators' training and assessment of operating skills on mobile special equipment.

  19. A new porous water ice stable at atmospheric pressure obtained by emptying a hydrogen filled ice

    CERN Document Server

    del Rosso, Leonardo; Ulivi, Lorenzo

    2016-01-01

    The properties of some forms of water ice reserve still intriguing surprises. We report here on the direct observation of a new form of ice, metastable at atmospheric pressure and having remarkable molecular adsorption ability. We study the crystalline solid compound of water and molecular hydrogen, called filled ice and indicated with C$_0$, that is formed at about 400 MPa and can be recovered at room pressure and low temperature, still containing a large fraction of molecular hydrogen. We perform x-rays diffraction to check the structure of the recovered sample. By means of Raman spectroscopy, we measure the hydrogen release at different temperatures, and succeed in rapidly removing all the hydrogen molecules, obtaining a new form of ice (ice XVII) which tolerate heating under vacuum up to about 120 K. Of paramount interest is the fact that the emptied crystal can adsorb again hydrogen and release it repeatedly, showing a temperature dependent hysteresis. We present here the first characterization of this n...

  20. Raman-free nonlinear optical effects in high pressure gas-filled hollow core PCF.

    Science.gov (United States)

    Azhar, M; Wong, G K L; Chang, W; Joly, N Y; Russell, P St J

    2013-02-25

    The effective Kerr nonlinearity of hollow-core kagomé-style photonic crystal fiber (PCF) filled with argon gas increases to ~15% of that of bulk silica glass when the pressure is increased from 1 to 150 bar, while the zero dispersion wavelength shifts from 300 to 900 nm. The group velocity dispersion of the system is uniquely pressure-tunable over a wide range while avoiding Raman scattering-absent in noble gases-and having an extremely high optical damage threshold. As a result, detailed and well-controlled studies of nonlinear effects can be performed, in both normal and anomalous dispersion regimes, using only a fixed-frequency pump laser. For example, the absence of Raman scattering permits clean observation, at high powers, of the interaction between a modulational instability side-band and a soliton-created dispersive wave. Excellent agreement is obtained between numerical simulations and experimental results. The system has great potential for the realization of reconfigurable supercontinuum sources, wavelength convertors and short-pulse laser systems.

  1. Assessment of bone-fill following regenerative periodontal therapy by image subtraction using commercially available software

    National Research Council Canada - National Science Library

    Pavan Yellarthi; Viswa Rampalli; Naveen Anumala; Rama Devaraju

    2014-01-01

    .... Settings and Design: For the bone-fill assessment, radiographs of 78 angular bone defects from 30 subjects who underwent periodontal flap surgery with hydroxyapatite bone graft placement were utilized...

  2. New Parameter Derived from Three-Dimensional Speckle-Tracking Echocardiography for the Estimation of Left Ventricular Filling Pressure in Nondilated Hearts.

    Science.gov (United States)

    Sakurai, Daisuke; Asanuma, Toshihiko; Masuda, Kasumi; Koriyama, Hikaru; Nakatani, Satoshi

    2017-05-01

    E/e' is clinically useful for the noninvasive assessment of left ventricular (LV) filling pressure. However, its use in some conditions is controversial, and angle dependence of the Doppler measurement and preload dependence of mitral e' in nondilated hearts represent major problems. The ratio of early filling rate derived from the time derivative of LV volume to early diastolic strain rate (FRe/SRe), similar to E/e', by three-dimensional (3D) speckle-tracking echocardiography has the potential to address such limitations. This study investigated whether FRe/SRe could estimate acute changes in LV filling pressure using the models of volume overload and myocardial ischemia in the nondilated heart. In 25 dogs, hemodynamic conditions were varied by acute volume overload and coronary occlusion. FRe and SRe were obtained from the same beat and automatically analyzed by the 3D speckle-tracking method, and global SRe was measured from longitudinal (L-SRe), circumferential (C-SRe), and area strain rate (A-SRe). E/e' was measured by two-dimensional echocardiography. LV pressure was derived from a micromanometer catheter and recorded simultaneously with the acquisition of the 3D images. Mitral e' and L-SRe varied by changes in preload, whereas C-SRe and A-SRe did not. C-SRe and A-SRe were more strongly correlated with the time constant of LV relaxation than mitral e' and L-SRe. FRe/C-SRe and FRe/A-SRe had relatively high correlations with LV preatrial contraction (pre-A) pressure and end-diastolic pressure, but E/e' and FRe/L-SRe did not. Receiver operating characteristics curve analysis showed that FRe/C-SRe and FRe/A-SRe had larger areas under the curve for the estimation of increased LV filling pressure. The novel parameter FRe/SRe has potential as a surrogate marker of LV filling pressure. Especially in nondilated hearts, FRe/C-SRe and FRe/A-SRe may be useful to more accurately predict LV filling pressure than E/e', although their applicability in dilated hearts

  3. Assessment of dome-fill technology and potential fill materials for the Hanford single-shell tanks

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, J.D.; Shade, J.W.; Somasundaram, S.

    1992-05-01

    This study is part of a task that will identify dome-fill materials to stabilize and prevent the collapse of the structures of 149 single- shell tanks (SSTs). The SSTs were built at the Hanford Site in Washington State and used between 1944 and 1980 to store radioactive and other hazardous wastes. In addition to identifying suitable fill materials, this task will develop the technology and methods required to fill the tanks with the selected material. To date, basalt is the only candidate fill material with any testing conducted for its suitability as a dome-fill material. Sufficient data do not exist to select or eliminate basalt as a candidate material. This report documents a review of past dome-fill work at the Hanford Site and of other pertinent literature to establish a baseline for the dome-fill technology. In addition, the report identifies existing dome-fill technology, preliminary performance criteria for dome-fill technology development, potential testing strategies, and potential fill materials. As a part of this study, potential fill materials are qualitatively evaluated and a list of preliminary candidate fill materials is identified. Future work will further screen these materials. The dome-fill task work will ultimately contribute to the development of a final waste form package and the safe isolation of wastes from the Hanford Site SSTs.

  4. Computed tomography assessment of the efficiency of different techniques for removal of root canal filling material

    Energy Technology Data Exchange (ETDEWEB)

    Dall' agnol, Cristina; Barletta, Fernando Branco [Lutheran University of Brazil, Canoas, RS (Brazil). Dental School. Dept. of Dentistry and Endodontics]. E-mail: fbarletta@terra.com.br; Hartmann, Mateus Silveira Martins [Uninga Dental School, Passo Fundo, RS (Brazil). Postgraduate Program in Dentistry

    2008-07-01

    This study evaluated the efficiency of different techniques for removal of filling material from root canals, using computed tomography (CT). Sixty mesial roots from extracted human mandibular molars were used. Root canals were filled and, after 6 months, the teeth were randomly assigned to 3 groups, according to the root-filling removal technique: Group A - hand instrumentation with K-type files; Group B - reciprocating instrumentation with engine-driven K-type files; and Group C rotary instrumentation with engine-driven ProTaper system. CT scans were used to assess the volume of filling material inside the root canals before and after the removal procedure. In both moments, the area of filling material was outlined by an experienced radiologist and the volume of filling material was automatically calculated by the CT software program. Based on the volume of initial and residual filling material of each specimen, the percentage of filling material removed from the root canals by the different techniques was calculated. Data were analyzed statistically by ANOVA and chi-square test for linear trend ({alpha}=0.05). No statistically significant difference (p=0.36) was found among the groups regarding the percent means of removed filling material. The analysis of the association between the percentage of filling material removal (high or low) and the proposed techniques by chi-square test showed statistically significant difference (p=0.015), as most cases in group B (reciprocating technique) presented less than 50% of filling material removed (low percent removal). In conclusion, none of the techniques evaluated in this study was effective in providing complete removal of filling material from the root canals. (author)

  5. Stability and Agreement of a Microtransducer and an Air-Filled Balloon Esophageal Catheter in the Monitoring of Esophageal Pressure.

    Science.gov (United States)

    Augusto, Renan Maloni; Albuquerque, André Luis Pereira; Jaeger, Thomas; de Carvalho, Carlos Roberto Ribeiro; Caruso, Pedro

    2017-02-01

    The use of esophageal catheters with microtransducer promises advantages over traditional catheters with air-filled balloons. However, performance comparisons between these 2 types of catheters are scarce and incomplete. A catheter with a 9.5-cm air-filled balloon at the distal tip and a catheter with a microtransducer mounted within a flexible silicone rubber were tested in vitro and in vivo. In vitro, the response times of both catheters were compared, and the drift of the baseline pressure of the microtransducer catheter was evaluated over a 6-h period. In vivo, 11 healthy volunteers had both catheters inserted, and the drift of the baseline esophageal pressure was measured over a 3-h period. Also, the correlation and agreement of the baseline and changes in the esophageal pressure of both catheters were evaluated. In vitro, the microtransducer catheter had a response time significantly higher (262 × 114 Hz, P pressure stability, with a mean baseline pressure drift of 1.4 cm H2O. In vivo, both catheters presented a small and similar baseline esophageal pressure drift (P = 0.08). For measurements of baseline and changes in esophageal pressure, the correlation and agreement between the catheters were poor, with a large bias between them. The catheter with the microtransducer had a small baseline pressure drift, similar to the air-filled balloon catheter. The low agreement between the catheters does not allow the microtransducer catheter to be used as a surrogate for the traditional air-filled balloon catheter. Copyright © 2017 by Daedalus Enterprises.

  6. Analysis on Filling Ratio and Shield Supporting Pressure for Overburden Movement Control in Coal Mining with Compacted Backfilling

    Directory of Open Access Journals (Sweden)

    Yanli Huang

    2016-12-01

    Full Text Available Since the weight of overburden is sustained by both the backfill body and the unmined solid coal in coal mining with compacted backfilling (CMCB panels, the stress and deformation characteristics of the surrounding rocks in coal mining are radically changed. The overburden movement control mechanism by coordinating with backfill body and shield in CMCB was studied systematically in this paper. Based on the analysis of deformational and structural characteristics of surrounding rock in CMCB panels, the methods of theoretical analysis, numerical simulation and engineering test are employed. The results show that the fracture of the main roof is mainly controlled by the filling ratio φ and is non-correlated to the shield supporting pressure p. However, p has a significant control effect on the deflection of roof within the shield canopy length, and adversely affects the filling ratio. With the increase of the filling ratio of the gob, the maximum sagging of the immediate and the main roofs, the peak front and the influence range of the abutment pressures are gradually reduced. Correspondingly, the stable period of internal pressure of backfill body in the gob is shortened. Engineering practice shows that the sagging of the gob roof, the distribution of the abutment pressure, the distribution of the internal pressure in the backfill body, and the ground surface sagging results obtained by the in-situ measurement are approximately corresponding to the theoretical analysis and numerical simulation results.

  7. High pressure gas filled RF cavity beam test at the Fermilab Mucool test area

    Science.gov (United States)

    Freemire, Ben

    With a new generation of lepton colliders being conceived, muons have been proposed as an alternative particle to electrons. Muons lose less energy to synchrotron radiation and a Muon Collider can provide luminosity within a smaller energy range than a comparable electron collider. This allows a circular collider to be built. As part of the accelerator, it would also be possible to allow the muons to decay to study neutrinos. Because the muon is an unstable particle, a muon beam must be cooled and accelerated within a short amount of time. Muons are generated with a huge phase space, so radio frequency cavities placed in strong magnetic fields are required to bunch, focus, and accelerate the muons. Unfortunately, traditional vacuum RF cavities have been shown to break down in the magnetic fields necessary. To successfully operate RF cavities in strong magnetic fields, the cavity can be filled with a high pressure gas in order to mitigate breakdown. The gas has the added benefit of providing cooling for the beam. The electron-ion plasma created in the cavity by the beam absorbs energy and degrades the accelerating electric field of the cavity. As electrons account for the majority of the energy loss in the cavity, their removal in a short time is highly desirable. The addition of an electronegative dopant gas can greatly decrease the lifetime of an electron in the cavity. Measurements in pure hydrogen of the energy consumption of electrons in the cavity range in 10-18 and 10-16 joules per RF cycle per electron. When hydrogen doped with dry air is used, measurements of the power consumption indicate an energy loss range of 10-20 to 10-18 joules per RF cycle per ion, two orders of magnitude improvement over non-doped measurements. The lifetime of electrons in a mixture of hydrogen gas and dry air has been measured from cooling-channel for either machine.

  8. Signal-Pressure Curves of Cascaded Four-Wave Mixing in Gas-Filled Capillary by fs Pulses

    Institute of Scientific and Technical Information of China (English)

    CHEN Bao-Zhen; HUANG Zu-Qia

    2005-01-01

    The theoretical framework for the cascaded four waves mixing (CFWM) in gas-filled capillary by fs pulses is constructed. Based on the theoretical framework, the signal-pressure curves (SPC) of the CFWM in gas-filled capillary by fs pulses are calculated. With a comparison between the theoretical and experimental SPC we have discussed the influence of the walk-off and Phase modulation on the SPC. At the same time, we have discussed the possible origin of the first three peaks of the SPC.

  9. Recording pressure ulcer risk assessment and incidence.

    Science.gov (United States)

    Plaskitt, Anne; Heywood, Nicola; Arrowsmith, Michaela

    2015-07-15

    This article reports on the introduction of an innovative computer-based system developed to record and report pressure ulcer risk and incidence at an acute NHS trust. The system was introduced to ensure that all patients have an early pressure ulcer risk assessment, which prompts staff to initiate appropriate management if a pressure ulcer is detected, thereby preventing further patient harm. Initial findings suggest that this electronic process has helped to improve the timeliness and accuracy of data on pressure ulcer risk and incidence. In addition, it has resulted in a reduced number of reported hospital-acquired pressure ulcers.

  10. Orthogonal tests of copper-clad aluminum bimetal continuous casting by nitrogen pressure core-filling

    National Research Council Canada - National Science Library

    Xue Zhiyong Liang He Yu Wanhua Wu Chunjing

    2013-01-01

    ... temperature, continuous casting speed and nitrogen pressure on the performance of composite rods. Results showed that nitrogen pressure is the most important factor in influencing the surface quality...

  11. Pressure sore risk assessment in palliative care.

    Science.gov (United States)

    Chaplin, J

    2000-01-01

    Pressure sore prevention in palliative care is recognized as being an essential element of holistic care, with the primary goal of promoting quality of life for patient and family. Little is known about the incidence of pressure sore development and the use of pressure sore risk assessment tools in palliative care settings. The development of a risk assessment tool specifically for palliative care patients in a 41-bedded specialist palliative care unit is described. The risk assessment tool was developed as part of a tissue viability practice development initiative. The approach adopted in the validation of the Hunters Hill Marie Curie Centre pressure sore risk assessment tool was the comparative analysis of professional judgment of experienced palliative care nurses with the numerical scores achieved during the assessment of risk on 291 patients (529 risk assessment events). This comparative analysis identified the threshold for different degrees of risk for the patient group involved: low risk, medium risk, high risk and very high risk. Further work is being undertaken to evaluate the inter-rater reliability of the new tool. A number of issues are explored in this paper in relation to pressure sore prevention in palliative care: the role of risk assessment tools, the sometimes conflicting aims of trying to ensure comfort and prevent pressure sore damage, and the uncertainties faced by palliative care nurses when they are trying to maintain quality of life for the dying.

  12. Design and fabrication of a data logger for atmospheric pressure, temperature and relative humidity for gas-filled detector development

    CERN Document Server

    Sahu, S; Rudra, Sharmili; Biswas, S; Mohanty, B; Sahu, P K

    2015-01-01

    A novel instrument has been developed to monitor and record the ambient pa- rameters such as temperature, atmospheric pressure and relative humidity. These parameters are very essential for understanding the characteristics such as gain of gas filled detectors like Gas Electron Multiplier (GEM) and Multi Wire Propor- tional Counter (MWPC). In this article the details of the design, fabrication and operation processes of the device has been presented.

  13. Pressure Measurements on a Deforming Surface in Response to an Underwater Explosion in a Water-Filled Aluminum Tube

    Directory of Open Access Journals (Sweden)

    G. Chambers

    2001-01-01

    Full Text Available Experiments have been conducted to benchmark DYSMAS computer code calculations for the dynamic interaction of water with cylindrical structures. Small explosive charges were suspended using hypodermic needle tubing inside Al tubes filled with distilled water. Pressures were measured during shock loading by tourmaline crystal, carbon resistor and ytterbium foil gages bonded to the tube using a variety of adhesives. Comparable calculated and measured pressures were obtained for the explosive charges used, with some gages surviving long enough to record results after cavitation with the tube wall.

  14. Structural changes of filled ice Ic hydrogen hydrate under low temperatures and high pressures from 5 to 50 GPa.

    Science.gov (United States)

    Hirai, Hisako; Kagawa, Shingo; Tanaka, Takehiko; Matsuoka, Takahiro; Yagi, Takehiko; Ohishi, Yasuo; Nakano, Satoshi; Yamamoto, Yoshitaka; Irifune, Tetsuo

    2012-08-21

    Low-temperature and high-pressure experiments were performed on the filled ice Ic structure of hydrogen hydrate at previously unexplored conditions of 5-50 GPa and 30-300 K using diamond anvil cells and a helium-refrigeration cryostat. In situ x-ray diffractometry revealed that the cubic filled ice Ic structure transformed to tetragonal at low temperatures and high pressures; the axis ratio of the tetragonal phase changed depending on the pressure and temperature. These results were consistent with theoretical predictions performed via first principle calculations. The tetragonal phase was determined to be stable above 20 GPa at 300 K, above 15 GPa at 200 K, and above 10 GPa at 100 K. Further changes in the lattice parameters were observed from about 45-50 GPa throughout the temperature region examined, which suggests the transformation to another high-pressure phase above 50 GPa. In our previous x-ray study that was performed up to 80 GPa at room temperature, a similar transformation was observed above 50 GPa. In this study, the observed change in the lattice parameters corresponds to the beginning of that transformation. The reasons for the transformation to the tetragonal structure are briefly discussed: the tetragonal structure might be induced due to changes in the vibrational or rotational modes of the hydrogen molecules under low temperature and high pressure.

  15. Examining the response pressure along a fluid-filled elastic tube to comprehend Frank's arterial resonance model.

    Science.gov (United States)

    Lin Wang, Yuh-Ying; Sze, Wah-Keung; Lin, Chin-Chih; Chen, Jiang-Ming; Houng, Chin-Chi; Chang, Chi-Wei; Wang, Wei-Kung

    2015-04-13

    Frank first proposed the arterial resonance in 1899. Arteries are blood-filled elastic vessels, but resonance phenomena for a fluid-filled elastic tube has not drawn much attention yet. In this study, we measured the pressure along long elastic tubes in response to either a single impulsive water ejection or a periodic water input. The experimental results showed the low damped pressure oscillation initiated by a single impulsive water input; and the natural frequencies of the tube, identified by the peaks of the response in the frequency domain, were inversely proportional to the length of the tube. We found that the response to the periodic input reached a steady distributed oscillation with the same period of the input after a short transient time; and the optimal pressure response, or resonance, occurred when the pumping frequency was near the fundamental natural frequency of the system. We pointed out that the distributed forced oscillation could also be a suitable approach to analyze the arterial pressure wave. Unlike Frank's resonance model in which the whole arterial system was lumped together to a simple 0-D oscillator and got only one natural frequency, a tube has more than one natural frequency because the pressure P(z,t) is a 1-D oscillatory function of the axial position z and the time t. The benefit of having more than one natural frequency was then discussed.

  16. Visualization of mold filling stages in thermal nanoimprint by using pressure gradients

    DEFF Research Database (Denmark)

    Schift, H.; Bellini, S.; Mikkelsen, Morten Bo Lindholm;

    2007-01-01

    A method for the visualization of mold filling during a thermoplastic imprint at a microscopic level was developed, which is based on superposition of images of a series of different states of imprint. The animated movie sequence gives an insight into the complex flow of polymer and shows how voi...

  17. Clinical review: Guyton - the role of mean circulatory filling pressure and right atrial pressure in controlling cardiac output

    OpenAIRE

    William R Henderson; Griesdale, Donald EG; Walley, Keith R; Sheel, A. William

    2010-01-01

    Arthur Guyton's concepts of the determinative role of right heart filling in cardiac output continue to be controversial. This paper reviews his seminal experiments in detail and clarifies the often confusing concepts underpinning his model. One primary criticism of Guyton's model is that the parameters describing venous return had not been measured in a functioning cardiovascular system in humans. Thus, concerns have been expressed in regard to the ability of Guyton's simplistic model, with ...

  18. Avaliação não invasiva das pressões de enchimento e remodelação do ventrículo esquerdo após infarto do miocárdio Non invasive assessment of left ventricular filling pressure and remodeling after acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Silvio Henrique Barberato

    2013-01-01

    Full Text Available FUNDAMENTO: A dilatação do ventrículo esquerdo (VE após infarto agudo do miocárdio (IAM é um importante determinante do prognóstico. A razão entre a velocidade diastólica E do fluxo mitral e a velocidade diastólica e' do anel mitral (relação E/e' é o melhor índice não invasivo para detectar elevação aguda da pressão de enchimento do VE. A hipótese deste estudo é que a E/e' possa predizer remodelação do VE após IAM tratado. OBJETIVO: Avaliar se a E/e' prediz remodelação ventricular após IAM, em comparação aos dados clínicos, laboratoriais e ecocardiográficos tradicionais. MÉTODO: Ecocardiogramas foram realizados em pacientes consecutivos com primeiro IAM, após angioplastia transluminal coronariana (ATC seguida de recanalização efetiva, 48 horas e 60 dias após o evento. A E/e' foi calculada pela média de quatro sítios do anel mitral. Remodelação do VE foi definida como aumento ≥ 15% do volume sistólico final ao método de Simpson. Análises estatísticas incluíram teste t de Student, curvas receptor-operador (ROC e regressão logística multivariada, com p significante BACKGROUND: Left ventricular (LV dilation after acute myocardial infarction (AMI is an important determinant of prognosis. The ratio of early mitral inflow velocity (E and peak early diastolic annular velocity (e' provides the best single index for noninvasive detection of acute elevation of LV filling pressure. OBJECTIVE: To assess whether E/e' ratio predicts LV remodeling after properly treated AMI compared with traditional clinical, laboratory and echocardiographic data. METHODS: Comprehensive echocardiograms were performed in a series of consecutive patients with first AMI successfully treated with primary percutaneous transluminal angioplasty (PTCA, both 48 hours after intervention and 60 days later. Mean E/e' was determined from four sites of the mitral annulus. LV remodeling was defined as more than 15% increase in end

  19. Prediction of Left Ventricular Filling Pressure by 3-Dimensional Speckle-Tracking Echocardiography in Patients With Coronary Artery Disease.

    Science.gov (United States)

    Ma, Hong; Xie, Rong-Ai; Gao, Li-Jian; Zhang, Jin-Ping; Wu, Wei-Chun; Wang, Hao

    2015-10-01

    The purpose of this study was to investigate the diagnostic value of 3-dimensional (3D) speckle-tracking echocardiography for estimating left ventricular filling pressure in patients with coronary artery disease (CAD) and a preserved left ventricular ejection fraction. Altogether, 84 patients with CAD and 30 age- and sex-matched healthy control participants in sinus rhythm were recruited prospectively. All participants underwent conventional and 3D speckle-tracking echocardiography. Global strain values were automatically calculated by 3D speckle-tracking analysis. The left ventricular end-diastolic pressure (LVEDP) was determined invasively by left heart catheterization. Echocardiography and cardiac catheterization were performed within 24 hours. Compared with the controls, patients with CAD showed lower global longitudinal strain, global circumferential strain, global area strain, and global radial strain. Patients with CAD who had an elevated LVEDP had much lower levels of all 4 3D-speckle-tracking echocardiographic variables. Pearson correlation analysis revealed that the LVEDP correlated positively with the early transmitral flow velocity/early diastolic myocardial velocity (E/E') ratio, global longitudinal strain, global circumferential strain, and global area strain. It correlated negatively with global radial strain. Receiver operating characteristic curve analysis revealed that these 3D speckle-tracking echocardiographic indices could effectively predict elevated left ventricular filling pressure (LVEDP >15 mm Hg) in patients with CAD (areas under the curve: global longitudinal strain, 0.78; global radial strain, 0.77; global circumferential strain, 0.75; and global area strain, 0.74). These parameters, however, showed no advantages over the commonly used E/E' ratio (area under the curve, 0.84). Three-dimensional speckle-tracking echocardiography was a practical technique for predicting elevated left ventricular filling pressure, but it might not be

  20. Assessment of Root Canal Filling Removal Effectiveness Using Micro-computed Tomography: A Systematic Review.

    Science.gov (United States)

    Rossi-Fedele, Giampiero; Ahmed, Hany Mohamed Aly

    2017-04-01

    The removal of obturation materials from the root canal system is a primary objective in root canal retreatment procedures. This systematic review aims to discuss the effectiveness of different instrumentation procedures in removing root-canal filling materials assessed by micro-computed tomography. An electronic search in PubMed and major endodontic journals was conducted using appropriate key words to identify investigations that examined the effectiveness of obturation material removal assessed by micro-computed tomography. Among 345 studies, 22 satisfied the inclusion criteria. Seven studies compared hand instrumentation with Nickel-Titanium rotary or reciprocating systems. Three studies investigated rotary systems, and another three studies explored reciprocation. Eight studies compared rotary systems and reciprocation in removing filling materials from the root canal system. Other factors, such as the role of solvents and irrigant agitation, were discussed. The application of different instrumentation protocols can effectively, but not completely, remove the filling materials from the root canal system. Only hand instrumentation was not associated with iatrogenic errors. Reciprocating and rotary systems exhibited similar abilities in removing root filling material. Retreatment files performed similarly to conventional ones. Solvents enhanced penetration of files but hindered cleaning of the root canal. The role of irrigant agitation was determined as controversial. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  1. Evaluation of pressure sensing concepts: A technology assessment

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, R.L.; Thacker, L.H.

    1993-09-01

    Advanced distributed control systems for electric power plants will require more accurate and reliable pressure gauges than those now installed. Future developments in power plant control systems are expected to use digital/optical networks rather than the analog/electric data transmission used in existing plants. Many pressure transmitters now installed use oil filling to separate process fluids from the gauge mechanism and are subject to insidious failures when the oil leaks. Testing and maintenance of pressure channels occupy a disproportionately large amount of effort to restore their accuracy and verify their operability. These and similar concerns have prompted an assessment of a broad spectrum of sensor technologies to aid in selecting the most likely candidates for adaptation to power plant applications. Ten representative conventional and thirty innovational pressure sensors are described and compared. Particular emphasis is focused on two categories: Silicon-integrated pressure sensors and fiber-optic sensors, and both of these categories are discussed in detail. Additional attractive concepts include variable reluctance gauges and resonant structure gauges that may not require oil buffering from the process fluid.

  2. Left ventricular filling pressure estimation at rest and during exercise in patients with severe aortic valve stenosis: comparison of echocardiographic and invasive measurements

    DEFF Research Database (Denmark)

    Dalsgaard, Morten; Kjaergaard, Jesper; Pecini, Redi;

    2009-01-01

    BACKGROUND: The Doppler index of left ventricular (LV) filling (E/e') is recognized as a noninvasive measure for LV filling pressure at rest but has also been suggested as a reliable measure of exercise-induced changes. The aim of this study was to investigate changes in LV filling pressure......, measured invasively as pulmonary capillary wedge pressure (PCWP), at rest and during exercise to describe the relation with E/e' in patients with severe aortic stenosis. METHODS: Twenty-eight patients with an aortic valve areas

  3. Modeling and experiments with low-frequency pressure wave propagation in liquid-filled, flexible tubes

    DEFF Research Database (Denmark)

    Bjelland, C; Bjarnø, Leif

    1992-01-01

    A model for wave propagation in a liquid-filled viscoelastic tube with arrays of receivers inside, is being used to analyze the influence of noise generated by in-line vibrational noise sources. In this model, distensibility is of greater importance than compressibility of the liquid....... The dispersion and attenuation is shown to be strongly dependent on the viscoelastic properties of the tube wall. The complex, frequency-dependent moduli of relevant tube materials have been measured in stress wave transfer function experiments. The moduli are used in the model to produce realistic dispersion...... relations and frequency-dependent attenuation. A 12-m-long, liquid-filled tube with interior stress members and connectors in each end is hanging vertically from an upper fixture. The lower end connector is excited by a power vibrator to generate the relevant wave modes. Measurements with reference...

  4. Left ventricular filling pressure in male patients with type 2 diabetes and normal versus low total testosterone levels.

    Science.gov (United States)

    Tinetti, Matias; Gysel, Michael; Farias, Javier; Ferrer, Mariano; Lombardero, Martin; Baranchuk, Adrian

    2015-01-01

    Heart failure is a common complication of diabetes characterized by an elevation in left ventricular filling pressures (LVF) that often develops in the absence of clinical symptoms. Diastolic dysfunction in the setting of low total testosterone (LTT) occurs through changes in the regulation of peripheral hemodynamics. LTT is highly prevalent among individuals with type 2 diabetes. The aim of this study was to compare LVF in male diabetic patients with no structural heart disease and normal serum testosterone levels vs. those with LTT. Type 2 diabetic patients were assessed using tissue Doppler imaging to evaluate LVF and other conventional parameters of diastolic function. The E/e' ratio was used to estimate LVF through the ratio of peak passive trans-mitral left ventricular inflow velocity to the peak passive inflow velocity at the lateral mitral annulus. Patients were assigned to one of two groups based upon their total testosterone levels. Group A consisted of low ( 3.5 ng/mL) testosterone levels. A total of 148 male patients were included: group A--47 (32%) patients; group B--101 (68%) patients, respectively. Mean age was 58 ± 5.8 years and mean time of diabetes evolution was 7 ± 3.1 years. There were no significant differences between the groups regarding age, duration of diabetes evolution, hypertension, weight, heart rate, body mass index, and echocardiographic parameters. The E/e' ratio for group A was 8.05 ± 1.9 vs. 6.1 ± 1.7 for group B (p < 0.0001). The E/A ratio was 0.94 ± 0.10 vs. 1.19 ± 0.12 (p = 0.01), deceleration time 242 ± 7.4 ms vs. 205 ± 9 ms (p = 0.026) and systolic pulmonary artery pressure 27 ± ± 2.2 mm Hg vs. 22 ± 1.7 mm Hg (p = 0.11). Patients with type 2 diabetes and LTT have a higher E/e' ratio demonstrating a pre-clinical increase in LVF when compared to similar patients with normal testosterone levels. This finding is independent of time of diabetes evolution, hypertension and other echocardiographic parameters.

  5. Clinical review: Guyton--the role of mean circulatory filling pressure and right atrial pressure in controlling cardiac output.

    Science.gov (United States)

    Henderson, William R; Griesdale, Donald E G; Walley, Keith R; Sheel, A William

    2010-01-01

    Arthur Guyton's concepts of the determinative role of right heart filling in cardiac output continue to be controversial. This paper reviews his seminal experiments in detail and clarifies the often confusing concepts underpinning his model. One primary criticism of Guyton's model is that the parameters describing venous return had not been measured in a functioning cardiovascular system in humans. Thus, concerns have been expressed in regard to the ability of Guyton's simplistic model, with few parameters, to model the complex human circulation. Further concerns have been raised in regard to the artificial experimental preparations that Guyton used. Recently reported measurements in humans support Guyton's theoretical and animal work.

  6. Study of high pressure gas filled RF cavities for muon collider

    CERN Document Server

    Yonehara, Katsuya

    2015-01-01

    Muon collider is a considerable candidate of the next-generation high-energy lepton collider machine. Operating an RF cavity in a multi-Tesla magnet is a critical requirement in a muon accelerator and a cooling channel. However, the maximum RF gradient in a vacuum RF cavity is strongly limited by an external magnetic field. Dense hydrogen gas filled RF cavity has been proposed since it is functional of generating a high RF accelerating gradient in a strong magnetic field and making an ionization cooling process at the same time. A critical issue of the cavity is a beam- induced plasma that consumes a considerable amount of RF power. The gas filled RF test cell was made and measured the RF loading due to a beam-induced plasma by using an intense proton beam at Fermilab. By doping an electronegative gas in dense hydrogen, the plasma loading effect is significantly mitigated. The result shows that the cavity is functional with a muon collider beam. Recent progress is shown in this presentation.

  7. Three-Dimensional Modelling inside a Differential Pressure Laminar Flow Bioreactor Filled with Porous Media

    Directory of Open Access Journals (Sweden)

    Birgit Weyand

    2015-01-01

    Full Text Available A three-dimensional computational fluid dynamics- (CFD- model based on a differential pressure laminar flow bioreactor prototype was developed to further examine performance under changing culture conditions. Cell growth inside scaffolds was simulated by decreasing intrinsic permeability values and led to pressure build-up in the upper culture chamber. Pressure release by an integrated bypass system allowed continuation of culture. The specific shape of the bioreactor culture vessel supported a homogenous flow profile and mass flux at the scaffold level at various scaffold permeabilities. Experimental data showed an increase in oxygen concentration measured inside a collagen scaffold seeded with human mesenchymal stem cells when cultured in the perfusion bioreactor after 24 h compared to static culture in a Petri dish (dynamic: 11% O2 versus static: 3% O2. Computational fluid simulation can support design of bioreactor systems for tissue engineering application.

  8. A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, C. A.; Blanchard, W. R.; Kozub, T. A.; Aristova, M.; McGahan, C.; Natta, S.; Pagdon, K.; Zelenty, J.

    2010-01-14

    An engineering evaluation has been initiated to investigate conceptual engineering methods for implementing a viable gas shield strategy in the Fusion Test Facility (FTF) target chamber. The employment of a low pressure noble gas in the target chamber to thermalize energetic helium ions prior to interaction with the wall could dramatically increase the useful life of the first wall in the FTF reactor1. For the purpose of providing flexibility, two target chamber configurations are addressed: a five meter radius sphere and a ten meter radius sphere. Experimental studies at Nike have indicated that a low pressure, ambient gas resident in the target chamber during laser pulsing does not appear to impair the ability of laser light from illuminating targets2. In addition, current investigations into delivering, maintaining, and processing low pressure gas appear to be viable with slight modification to current pumping and plasma exhaust processing technologies3,4. Employment of a gas fill solution for protecting the dry wall target chamber in the FTF may reduce, or possibly eliminate the need for other attenuating technologies designed for keeping He ions from implanting in first wall structures and components. The gas fill concept appears to provide an effective means of extending the life of the first wall while employing mostly commercial off the shelf (COTS) technologies. Although a gas fill configuration may provide a methodology for attenuating damage inflicted on chamber surfaces, issues associated with target injection need to be further analyzed to ensure that the gas fill concept is viable in the integrated FTF design5. In the proposed system, the ambient noble gas is heated via the energetic helium ions produced by target detonation. The gas is subsequently cooled by the chamber wall to approximately 800oC, removed from the chamber, and processed by the chamber gas processing system (CGPS). In an optimized scenario of the above stated concept, the chamber

  9. Pressure-assisted melt-filling and optical characterization of Au nano-wires in microstructured fibers.

    Science.gov (United States)

    Lee, H W; Schmidt, M A; Russell, R F; Joly, N Y; Tyagi, H K; Uebel, P; Russell, P St J

    2011-06-20

    We report a novel splicing-based pressure-assisted melt-filling technique for creating metallic nanowires in hollow channels in microstructured silica fibers. Wires with diameters as small as 120 nm (typical aspect ration 50:1) could be realized at a filling pressure of 300 bar. As an example we investigate a conventional single-mode step-index fiber with a parallel gold nanowire (wire diameter 510 nm) running next to the core. Optical transmission spectra show dips at wavelengths where guided surface plasmon modes on the nanowire phase match to the glass core mode. By monitoring the side-scattered light at narrow breaks in the nanowire, the loss could be estimated. Values as low as 0.7 dB/mm were measured at resonance, corresponding to those of an ultra-long-range eigenmode of the glass-core/nanowire system. By thermal treatment the hollow channel could be collapsed controllably, permitting creation of a conical gold nanowire, the optical properties of which could be monitored by side-scattering. The reproducibility of the technique and the high optical quality of the wires suggest applications in fields such as nonlinear plasmonics, near-field scanning optical microscope tips, cylindrical polarizers, optical sensing and telecommunications.

  10. Nonmagnetic Ground State in Fully Filled PrxFe4Sb12 (x=1.0) Synthesized under High Pressure

    Science.gov (United States)

    Tanaka, Kenya; Kawahito, Yusuke; Yonezawa, Yuki; Kikuchi, Daisuke; Aoki, Hidekazu; Kuwahara, Keitaro; Ichihara, Masaki; Sugawara, Hitoshi; Aoki, Yuji; Sato, Hideyuki

    2007-10-01

    We have succeeded in synthesizing the filled skutterudite PrxFe4Sb12 with the Pr-site filling fraction x close to 1 under high pressure. The residual resistivity of ˜24 μΩ\\cdotcm is several times smaller than that of samples with x˜ 0.8 synthesized under ambient pressure by independent research groups, indicating that highly improved sample quality can be achieved by reducing the Pr-site vacancy. From the transport, magnetic, and thermal measurements of the present sample with x˜ 1, we have found a singlet ground state of the crystalline electric field (CEF) for 4f-electrons and no phase transition down to 0.15 K, in contrast to the reported magnetic ordering near 5 K in the samples with x˜ 0.8. The effect of the Pr-site vacancy on the CEF level scheme and the 3d-electron density of states near the Fermi level is discussed as a possible origin of such a drastic change in the magnetic ground state.

  11. Electrical admittance for filling of the heart during lower body negative pressure in humans

    DEFF Research Database (Denmark)

    Cai, Yujia; Holm, S; Jenstrup, M;

    2000-01-01

    lower body negative pressure (LBNP) in humans. Changes in Thorax(ICW) were compared with positron emission tomography-determined C(15)O-labeled erythrocytes over the heart. During -40 mmHg LBNP, the blood volume of the heart decreased by 21 +/- 3% as the erythrocyte volume was reduced by 20 +/- 2...

  12. Pressure wave propagation in fluid-filled co-axial elastic tubes. Part 2: Mechanisms for the pathogenesis of syringomyelia.

    Science.gov (United States)

    Carpenter, P W; Berkouk, K; Lucey, A D

    2003-12-01

    Our aim in this paper is to use a simple theoretical model of the intraspinal cerebrospinal-fluid system to investigate mechanisms proposed for the pathogenesis of syringomyelia. The model is based on an inviscid theory for the propagation of pressure waves in co-axial, fluid-filled, elastic tubes. According to this model, the leading edge of a pressure pulse tends to steepen and form an elastic jump, as it propagates up the intraspinal cerebrospinal-fluid system. We show that when an elastic jump is incident on a stenosis of the spinal subarachnoid space, it reflects to form a transient, localized region of high pressure within the spinal cord that for a cough-induced pulse is estimated to be 50 to 70 mm Hg or more above the normal level in the spinal subarachnoid space. We propose this as a new mechanism whereby pressure pulses created by coughing or sneezing can generate syrinxes. We also use the same analysis to investigate Williams' suck mechanism. Our results do not support his concept, nor, in cases where the stenosis is severe, the differential-pressure-propagation mechanism recently proposed by Greitz et al. Our analysis does provide some support for the piston mechanism recently proposed by Oldfield et al. and Heiss et al. For instance, it shows clearly how the spinal cord is compressed by the formation of elastic jumps over part of the cardiac cycle. What appears to be absent for this piston mechanism is any means whereby the elastic jumps can be focused (e.g., by reflecting from a stenosis) to form a transient, localized region of high pressure within the spinal cord. Thus it would seem to offer a mechanism for syrinx progression, but not for its formation.

  13. Standard practice for examination of seamless, Gas-Filled, pressure vessels using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This practice provides guidelines for acoustic emission (AE) examinations of seamless pressure vessels (tubes) of the type used for distribution or storage of industrial gases. 1.2 This practice requires pressurization to a level greater than normal use. Pressurization medium may be gas or liquid. 1.3 This practice does not apply to vessels in cryogenic service. 1.4 The AE measurements are used to detect and locate emission sources. Other nondestructive test (NDT) methods must be used to evaluate the significance of AE sources. Procedures for other NDT techniques are beyond the scope of this practice. See Note 1. Note 1—Shear wave, angle beam ultrasonic examination is commonly used to establish circumferential position and dimensions of flaws that produce AE. Time of Flight Diffraction (TOFD), ultrasonic examination is also commonly used for flaw sizing. 1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only. 1.6 This standa...

  14. Acoustoelastic effects on mode waves in a fluid-filled pressurized borehole in triaxially stressed formations

    Institute of Scientific and Technical Information of China (English)

    Ping'en Li; Youquan Yin; Xianyue Su

    2006-01-01

    Based on the nonlinear theory of acoustoelasticity,considering the triaxial terrestrial stress,the fluid static pressure in the borehole and the fluid nonlinear effect jointly,the dispersion curves of the monopole Stoneley wave and dipole flexural wave propagating along the borehole axis in a homogeneous isotropic formation are investigated by using the perturbation method.The relation of the sensitivity coefficient and the velocity-stress coefficient to frequency are also analyzed.The results show that variations of the phase velocity dispersion curve are mainly affected by three sensitivity coefficients related to third-order elastic constant.The borehole stress concentration causes a split of the flexural waves and an intersection of the dispersion curves of the flexural waves polarized in directions parallel and normal to the uniaxial horizontal stress direction.The stress-induced formation anisotropy is only dependent on the horizontal deviatoric terrestrial stress and independent of the horizontal mean terrestrial stress,the superimposed stress and the fluid static pressure.The horizontal terrestrial stress ratio ranging from 0 to 1 reduces the stress-induced formation anisotropy.This makes the intersection of flexural wave dispersion curves not distinguishable.The effect of the fluid nonlinearity on the dispersion curve of the mode wave is small and can be ignored.

  15. The glow duration time influence on the ionization rate detected in the diodes filled with noble gases on mbar pressures

    Directory of Open Access Journals (Sweden)

    Stepanović Olivera M.

    2003-01-01

    Full Text Available The results of the glow current duration time (glowing-time influence on the ionization rate detected in the gas filled diodes are presented. The electrical breakdown was detected as the minimal current impulse. After that diode glow from the minimal glowing-time (10-3 s, up to the maximal 103 s which overlap the time of the stationary regime formation in the gas diode tube. The diodes were with volumes of 300 cm3, but with a diode gap volume of about 1 cm3 and filled with helium, neon, argon or krypton, at the pressures of the order of mbar. The ionization rates were detected as the residual ionization after the glowing was interrupted, using the electrical breakdown time delay measuring method. The influence of the gap distance stationary current values and the relaxation period were also investigated. The result shows that the stationary regime in such a gas diode is established after the glowing time of 1-3 s, although the breakdown formative times were smaller then 1 ms.

  16. Photon-counting digital radiography using high-pressure xenon filled detectors

    CERN Document Server

    Li, Maozhen; Johns, P C

    2001-01-01

    Digital radiography overcomes many of the limitations of the traditional screen/film system. Further enhancements in the digital radiography image are possible if the X-ray image receptor could measure the energy of individual photons instead of simply integrating their energy, as is the case at present. A prototype photon counting scanned projection radiography system has been constructed, which combines a Gas Electron Multiplier (GEM) and a Gas Microstrip Detector (GMD) using Xe : CH sub 4 (90 : 10) at high pressure. With the gain contribution from the GEM, the GMD can be operated at lower and safer voltages making the imaging system more reliable. Good energy resolution, and spatial resolution comparable to that of screen/film, have been demonstrated for the GEM/GMD hybrid imaging system in photon counting mode for X-ray spectra up to 50 kV.

  17. The echocardiographic estimation of left ventricular filling pressures in patients with mitral valve stenosis

    Directory of Open Access Journals (Sweden)

    Sattarzadeh Badkoubeh R

    2010-08-01

    Full Text Available "nBackground: Estimation of Left Ventricular End Diastolic Pressure (LVEDP among patients with Mitral Stenosis (MS helps to diagnose diastolic dysfunction and to explain their symptoms. However, Conventional Doppler measurements have limitation in predicting of LVEDP. This study sought to establish whether the correlation between measurements derived from Tissue Doppler echocardiography and LVEDP remains valid in the setting of severe mitral stenosis. "n"nMethods: Thirty three patients with moderate to severe MS who had indication for left heart catheterization enrolled during 1387-88 in Imam Khomeini Hospital in Tehran, Iran. The mean diastolic transmitral pressure gradient and mitral valve area (MVA were calculated, and Two-dimensional, M-mode, color Doppler and tissue Doppler Imaging indices such as: early diastolic mitral inflow velocity (E, annular early diastolic velocity (Ea, E/A ratio, Isovolemic relaxation time (IVRT, Pulmonary Vein systolic and diastolic flow velocities, Velocity Propagation, LA size, TE-Ea, Tei Index were obtained in maximum three hours before cardiac catheterization. The echocardiography analysis was performed offline without knowledge of hemodynamic data Linear correlation and multiple linear regression were used for analysis. p< 0.05 was considered significant. "n"nResults: In univariate analysis, E/Ea was associated with LVEDP significantly (p = 0.04, r = 0.38. There was also a significant correlation between TE-Ea and LVDP (p = 0.01, r = -0.44. In multiple linear regression Tei Index (ß = 0.4, p< 0.02, and TE-Ea (ß = 0.5, p = 0.02 were showed as independent predictors of LVEDP (R2 = 49%. "n"nConclusion: Although we observed a moderate correlation between Doppler measurements and LVEDP in patients with severe MS, more similar studies are required.

  18. An improved mathematical model to simulate mold filling process in high pressure die casting using CLSVOF method and CSF model

    Directory of Open Access Journals (Sweden)

    Cheng Bi

    2015-05-01

    Full Text Available A 3D mathematical model was proposed to simulate the mold filling process in high-pressure die casting (HPDC to improve accuracy considering the surface tension. Piecewise liner interface calculation (PLIC and volume of fluid (VOF methods were used to construct the pattern of the liquid interface. A coupled level-set and VOF method (CLSVOF was proposed to capture the interface pattern and obtain its normal vector. A continuum surface force (CSF model was used to consider the surface tension. Two water analogy experiments were carried out using the proposed model. Simulation and experimental results were analyzed and compared; and the effects of surface tension were also discussed. The simulation results agreed well with the experiments and the simulation accuracy was an improvement on interface geometries, liquid flows, and gas entrapments.

  19. High-pressure synthesis of the filled skutterudite PrFe{sub 4}Sb{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kenya [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)]. E-mail: tanaka-kenya@c.metro-u.ac.jp; Kawahito, Yusuke [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Kikuchi, Daisuke [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Aoki, Hidekazu [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Aoki, Yuji [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Sato, Hideyuki [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)

    2006-05-01

    We have succeeded in synthesizing the filled skutterudite PrFe{sub 4}Sb{sub 12} crystals at high pressures and temperatures. To investigate bulk properties, we measured the magnetic susceptibility down to 2K and electrical resistivity down to 0.7K. The magnetic susceptibility exhibits a broad maximum around 10K and follows the Curie Weiss law above {approx}150K with the effective magnetic moment of 4.5{mu}{sub B}/f.u. The electrical resistivity increases with increasing temperature up to room temperature exhibiting tendencies to saturation at around 10 and 100K. The relatively large residual resistivity ratio of {approx}24 suggests high quality of the grown sample.

  20. Condition Assessment of PC Tendon Duct Filling by Elastic Wave Velocity Mapping

    Directory of Open Access Journals (Sweden)

    Kit Fook Liu

    2014-01-01

    Full Text Available Imaging techniques are high in demand for modern nondestructive evaluation of large-scale concrete structures. The travel-time tomography (TTT technique, which is based on the principle of mapping the change of propagation velocity of transient elastic waves in a measured object, has found increasing application for assessing in situ concrete structures. The primary aim of this technique is to detect defects that exist in a structure. The TTT technique can offer an effective means for assessing tendon duct filling of prestressed concrete (PC elements. This study is aimed at clarifying some of the issues pertaining to the reliability of the technique for this purpose, such as sensor arrangement, model, meshing, type of tendon sheath, thickness of sheath, and material type as well as the scale of inhomogeneity. The work involved 2D simulations of wave motions, signal processing to extract travel time of waves, and tomography reconstruction computation for velocity mapping of defect in tendon duct.

  1. Mean circulatory filling pressure during splanchnic nerve stimulation and whole-body hypoxia in the anaesthetized cat.

    Science.gov (United States)

    Bower, E A; O'Donnell, C P

    1991-01-01

    1. Mean circulatory filling pressure (MCFP) was measured in cats under chloralose anaesthesia by obstruction of blood flow in the pulmonary artery. Pressures in the aorta, hepatic portal vein and right atrium were recorded, and MCFP was estimated from the value at which all three pressures became equal when blood was pumped from aorta to vena cava during circulatory arrest. Simultaneous equality was not attained at MCFP values below 5 mmHg. 2. In cats ventilated by positive pressure after administration of gallamine, MCFP was 9.7 +/- 0.3 mmHg (n = 14). The values of MCFP measured in six cats before and after administration of gallamine did not differ significantly. Change of blood volume altered MCFP linearly over the range 5-21 mmHg. Noradrenaline (7.5 micrograms kg-1 min-1) increased MCFP from 9.3 +/- 0.9 to 16.5 +/- 0.6 mmHg (n = 4), and phentolamine (2 mg kg-1) reduced it to 5.6 +/- 0.3 mmHg (n = 5). 3. Changes in MCFP were evoked at different circulating blood volumes by stimulation of the splanchnic sympathetic nerves and by whole-body hypoxia. Ablation of all splanchnic nerves reduced MCFP from 9.4 +/- 0.5 to 7.1 +/- 0.3 mmHg (n = 5) and stimulation of their distal ends at 10 Hz increased it by 4.1 +/- 0.4 mmHg (n = 4); similar increments were obtained at different blood volumes and initial values of MCFP. 4. Hypoxia increased MCFP by 0.23 mmHg per 1 mmHg fall in arterial oxygen tension below Pa,O2 56 mmHg (r = -0.86; n = 24). Similar increments were obtained at different blood volumes and initial values of MCFP. Ablation of all splanchnic nerves reduced the increments by 60%, and administration of phentolamine abolished them.

  2. Health risk assessment linked to filling coastal quarries with treated dredged seaport sediments

    Energy Technology Data Exchange (ETDEWEB)

    Perrodin, Yves, E-mail: yves.perrodin@entpe.fr [Université de Lyon, ENTPE, UMR CNRS 5023, Laboratoire LEHNA, 2 rue Maurice Audin, 69518 Vaulx-en-Velin (France); Donguy, Gilles [Université de Lyon, ENTPE, UMR CNRS 5023, Laboratoire LEHNA, 2 rue Maurice Audin, 69518 Vaulx-en-Velin (France); Emmanuel, Evens [Laboratoire de Qualité de l' Eau et de l' Environnement, Université Quisqueya, BP 796 Port-au-Prince (Haiti); Winiarski, Thierry [Université de Lyon, ENTPE, UMR CNRS 5023, Laboratoire LEHNA, 2 rue Maurice Audin, 69518 Vaulx-en-Velin (France)

    2014-07-01

    Dredged seaport sediments raise complex management problems since it is no longer possible to discharge them into the sea. Traditional waste treatments are poorly adapted for these materials in terms of absorbable volumes and cost. In this context, filling quarries with treated sediments appears interesting but its safety regarding human health must be demonstrated. To achieve this, a specific methodology for assessing health risks has been developed and tested on three seaport sediments. This methodology includes the development of a conceptual model of the global scenario studied and the definition of specific protocols for each of its major steps. The approach proposed includes in particular the use of metrological and experimental tools that are new in this context: (i) an experimental lysimeter for characterizing the deposit emissions, and (ii) a geological radar for identifying potential preferential pathways between the sediment deposit and the groundwater. The application of this approach on the three sediments tested for the scenario studied showed the absence of health risk associated with the consumption of groundwater for substances having a “threshold effect” (risk quotient < 1), and an acceptable risk for substances having a “non-threshold effect”, with the notable exception of arsenic (individual risk equal to 3.10{sup −6}). - Highlights: • The release of polluted dredged seaport sediments into the sea must be avoided. • Their use after treatment for the filling-up of quarries is proposed by managers. • An original health risk assessment methodology was created to validate this option. • It includes the use of a lysimeter and a georadar for the exposure assessment stage. • The example studied concludes to a health risk linked to arsenic in the groundwater.

  3. Assessment of periapical health, quality of root canal filling, and coronal restoration by using cone-beam computed tomography.

    Science.gov (United States)

    Cakici, E B; Yildirim, E; Cakici, F; Erdogan, A S

    2016-01-01

    The purpose of this study is to use cone-beam computed tomography (CBCT) to describe the prevalence of apical health, the quality of root canal filling, and coronal restorations of endodontically treated teeth in the east Anatolian subpopulation of Turkey. CBCT scans were taken from 748 patients attending for the 1st time to the clinic at the Oral Diagnosis and Radiology Department at Ataturk University's Faculty of Dentistry in Erzurum, Turkey. All images were analyzed by two research assistants who were trained using examples of CBCT images with and without the presence of periapical radiolucency. The two examiners assessed images from the experiment independently, and the readings were then compared. All data were entered on an MS Excel 2007 spreadsheet and SPSS software 15.0 which was used for statistical analysis. The Chi-square test was used to determine if a patient's periapical status was associated with the technical quality of root filling, coronal status, and to evaluate differences between tooth subgroups. In total, 147 teeth from 748 patients were found to have been treated endodontically. Sixty three teeth were found to have short root canal fillings, whereas 74 teeth had adequate root canal fillings, and the remaining 10 teeth had over extended root canal filling. A significant correlation was observed between the length of root filling and apical periodontitis (P = 0,023). Inadequately dense root canal filling was observed in 141 teeth, whereas adequately dense filling was found in only six teeth. There was a significant correlation between the density of root filling and apical periodontitis (P = 0.044). Coronal restoration was found in 90 teeth, but was not observed in all the three teeth. A crown was present in 54 teeth. There was a significant correlation between coronal restoration and apical periodontitis (P = 0.028). The results indicate that the quality of both the root filling and restoration were found to have impact on the periapical

  4. Damage assessment for seismic response of recycled concrete filled steel tube columns

    Science.gov (United States)

    Huang, Yijie; Xiao, Jianzhuang; Shen, Luming

    2016-09-01

    A model for evaluating structural damage of recycled aggregate concrete filled steel tube (RCFST) columns under seismic effects is proposed in this paper. The proposed model takes the lateral deformation and the effect of repeated cyclic loading into account. Available test results were collected and utilized to calibrate the parameters of the proposed model. A seismic test for six RCFST columns was also performed to validate the proposed damage assessment model. The main test parameters were the recycled coarse aggregate (RCA) replacement percentage and the bond-slip property. The test results indicated that the seismic performance of the RCFST member depends on the RCA contents and their damage index increases as the RCA replacement percentage increases. It is also indicated that the damage degree of RCFST changes with the variation of the RCA replacement percentage. Finally, comparisons between the RCA contents, lateral deformation ratio and damage degree were implemented. It is suggested that an improvement procedure should be implemented in order to compensate for the performance difference between the RCFST and normal concrete filled steel tubes (CFST).

  5. Estimation of diastolic filling pressure with cardiac CT in comparison with echocardiography using tissue doppler imaging: Determination of optimal CT reconstruction parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Sun; Suh, Jon; Lee, Heon [Soonchunhyang University Hospital Bucheon, Bucheon (Korea, Republic of); Lee, Bora [Dept. of Biostatistics, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of); Lee, Soo Jeong [Terarecon Korea, Seoul (Korea, Republic of); Jou, Sung Shick [Dept. of Radiology, Soonchunhyang University Hospital Cheonan, Cheonan (Korea, Republic of); Lim, Hyun Kyung [Dept. of Radiology, Soonchunhyang University Hospital Seoul, Seoul (Korea, Republic of)

    2017-08-01

    To determine the optimal CT image reconstruction parameters for the measurement of early transmitral peak velocity (E), early peak mitral septal tissue velocity (E′), and E / E′. Forty-six patients underwent simultaneous cardiac CT and echocardiography on the same day. Four CT datasets were reconstructed with a slice thickness/interval of 0.9/0.9 mm or 3/3 mm at 10 (10% RR-interval) or 20 (5% RR-interval) RR-intervals. The E was calculated by dividing the peak transmitral flow (mL/s) by the corresponding mitral valve area (cm{sup 2}). E′ was calculated from the changes in the left ventricular length per cardiac phase. E / E′ was then estimated and compared with that from echocardiography. For assessment of E / E′, CT and echocardiography were more strongly correlated (p < 0.05) with a slice thickness of 0.9 mm and 5% RR-interval (r = 0.77) than with 3 mm or 10% RR-interval. The diagnostic accuracy of predicting elevated filling pressure (E / E′ ≥ 13, n = 14) was better with a slice thickness of 0.9 mm and 5% RR-interval (87.0%) than with 0.9 mm and 10% RR-interval (71.7%) (p = 0.123) and significantly higher than that with a slice thickness of 3 mm with 5% (67.4%) and 10% RR-interval (63.0%), (p < 0.05), respectively. Data reconstruction with a slice thickness of 0.9 mm at 5% RR-interval is superior to that with a slice thickness of 3 mm or 10% RR-interval in terms of the correlation of E / E′ between CT and echocardiography. Thin slices and frequent sampling also allow for more accurate prediction of elevated filling pressure.

  6. Metallization of (TTM-TTP)I3 with a Highly One-Dimensional Half-Filled Band under Extremely High Pressure

    Science.gov (United States)

    Yasuzuka, Syuma; Murata, Keizo; Fujimoto, Tsutomu; Shimotori, Masahiro; Kawamoto, Tadashi; Mori, Takehiko; Hedo, Masato; Uwatoko, Yoshiya

    2006-05-01

    The title compound (TTM-TTP)I3 with a highly one-dimensional (1D) half-filled energy band is almost metallized by the application of pressure beyond 7 GPa. It is theoretically predicted that the ground state of the 1D half-filled system is the Mott insulator at any positive on-site interaction U. Nevertheless, (TTM-TTP)I3 shows that the metal-insulator (M-I) transition temperature TMI decreases linearly with increasing pressure and is directing towards 0 K near 10 GPa. Above 5.7 GPa, the metallic temperature variation appears in the high-temperature region for 70 model.

  7. The origin and clinical significance of the signal opposite to the mitral E-wave: a simple and novel indicator of left ventricular filling pressure.

    Science.gov (United States)

    Makita, Yuko; Okamoto, Mitsunori; Yoshida, Naoyasu; Hashimoto, Masaki; Shintani, Yumiko; Kajihara, Kenta; Nakano, Yukiko; Kihara, Yasuki

    2011-07-01

    We noted a low-velocity signal opposite to the early diastolic transmitral flow (E) by pulsed Doppler echocardiography. The purpose of this study was to examine the origin and significance of this signal. The background of the signal remains uncertain. We studied 59 adult patients (34 men and 25 women; mean age, 58.9 [20.2] years) without mitral valve heart disease. Mitral E-wave velocity and the signal (EW) opposite the E-wave were measured by pulsed Doppler echocardiography. Early diastolic mitral valve ring motion velocity (Ea) was measured by pulsed tissue Doppler echocardiography. Pulmonary capillary wedge pressure (PCWP) was measured by a Swan-Ganz catheter in 34 of the 59 patients. A blue signal was observed during early diastole from the mitral valve ring to the mitral orifice areas by color tissue Doppler echocardiography. The velocity profile method revealed the same direction and time between peak Ea and EW. Peak EW positively correlated with Ea (r = 0.67, P 12 mmHg than in patients with PCWP ≤ 12 mmHg (5.6 [1.3] cm/s vs. 4.3 [0.9] cm/s, P < 0.01). EW may be related to mitral valve ring motion, and the E/EW ratio may be a noninvasive simple parameter for assessing left ventricular filling pressure. © 2011, Wiley Periodicals, Inc.

  8. Visual Impairment/Intracranial Pressure Risk Assessment

    Science.gov (United States)

    Fogarty, Jennifer A.; Durham, T.; Otto, C.; Grounds, D.; Davis, J. R.

    2010-01-01

    Since 2006 there have been 6 reported cases of altered visual acuity and intracranial pressure (ICP) in long duration astronauts. In order to document this risk and develop an integrated approach to its mitigation, the NASA Space Life Sciences Directorate (SLSD) and Human Research Program (HRP) have chosen to use the Human System Risk Board (HSRB) and the risk management analysis tool (RMAT). The HSRB is the venue in which the stakeholders and customers discuss and vet the evidence and the RMAT is the tool that facilitates documentation and comparison of the evidence across mission profiles as well as identification of risk factors, and documentation of mitigation strategies. This process allows for information to be brought forward and dispositioned so that it may be properly incorporated into the RMAT and contribute to the design of the research and mitigation plans. The evidence thus far has resulted in the identification of a visual impairment/intracranial pressure (VIIP) project team, updating of both short and long duration medical requirements designed to assess visual acuity, and a research plan to characterize this issue further. In order to understand this issue more completely, a plan to develop an Accelerated Research Collaboration (ARC) has been approved by the HSRB. The ARC is a novel research model pioneered by the Myelin Repair Foundation. It is a patient centered research model that brings together researchers and clinicians, under the guidance of a scientific advisory panel, to collaborate and produce results much quickly than accomplished through traditional research models. The data and evidence from the updated medical requirements and the VIIP ARC will be reviewed at the HSRB on a regular basis. Each review package presented to the HSRB will include an assessment and recommendation with respect to continuation of research, countermeasure development, occupational surveillance modalities, selection criteria, etc. This process will determine the

  9. Research and Correlation of Diagnostic Methods for Assessment of the State of Oil Filling in Cycloid Gearbox

    Directory of Open Access Journals (Sweden)

    Petr Baron

    2015-01-01

    Full Text Available The paper describes the research in the area of the application of diagnostic methods for assessment of the state of oil filling in cycloid gearbox of robotic manipulator. The experiments were realized on request of the manufacturer of the cycloid gearbox. Primarily, the two different methods were compared: an induction, magnetic method with the use of measurement system Cosmos-Steel Dust Checker and an RTG method, XRF (X-ray fluorescent method, analyses with use of X-ray radiation. These analytical methods provide the identification and quantification of emerging Fe abrasion particles occurring in the oil filling of the redactor. The results of the experiment pointed to the unsuitability of the application of the induction magnetic method for the assessment of an actual technical state of the cycloid gearbox. The reason for this lies in specific construction of the cycloid gearbox, with characteristic high operation temperatures of the oil filling, small dimensions, high transferred power, and gear ratio.

  10. Health risk assessment linked to filling coastal quarries with treated dredged seaport sediments.

    Science.gov (United States)

    Perrodin, Yves; Donguy, Gilles; Emmanuel, Evens; Winiarski, Thierry

    2014-07-01

    Dredged seaport sediments raise complex management problems since it is no longer possible to discharge them into the sea. Traditional waste treatments are poorly adapted for these materials in terms of absorbable volumes and cost. In this context, filling quarries with treated sediments appears interesting but its safety regarding human health must be demonstrated. To achieve this, a specific methodology for assessing health risks has been developed and tested on three seaport sediments. This methodology includes the development of a conceptual model of the global scenario studied and the definition of specific protocols for each of its major steps. The approach proposed includes in particular the use of metrological and experimental tools that are new in this context: (i) an experimental lysimeter for characterizing the deposit emissions, and (ii) a geological radar for identifying potential preferential pathways between the sediment deposit and the groundwater. The application of this approach on the three sediments tested for the scenario studied showed the absence of health risk associated with the consumption of groundwater for substances having a "threshold effect" (risk quotient <1), and an acceptable risk for substances having a "non-threshold effect", with the notable exception of arsenic (individual risk equal to 3.10(-6)). Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Community health needs assessments: filling data gaps for population health research and management.

    Science.gov (United States)

    Alberti, Philip

    2014-01-01

    Community health needs assessments (CHNA) are completed to meet varied regulatory and statutory requirements for local public health departments, tax-exempt 501(c)(3) hospitals, and Federally Qualified Health Centers. Although compliance is a motivating factor, these entities are committed to understanding the communities they serve and to developing strategies to address health needs and inequities in health and health care. CHNAs have the potential to improve the health of communities and populations by giving crucial qualitative and quantitative context to hospital and patient data, thereby enhancing opportunities for health services and clinical outcomes researchers. Filling in these data gaps can help to improve population health by highlighting community-and social determinant-related dynamics relevant to the improved health of the community. Successful models exist that that have used CHNAs and the resulting data to improve population health management and reduce inequities, as do health systems that have used the EHR and community-based performance measurement data to achieve population health goals.

  12. AN IN VITRO ASSESSMENT OF CORONAL MICROLEAKAGE IN ROOT-FILLED TEETH

    Directory of Open Access Journals (Sweden)

    Sînziana Adina SCĂRLĂTESCU

    2013-03-01

    Full Text Available Aim. To evaluate the marginal seal of temporary restorations in endodontically-treated teeth by comparing three restorative materials and two techniques of root canal filling. Materials and method. Canal shaping was completed on 72 single-root teeth using a ProTaper system and root filling by lateral or vertical condensation. 8 teeth have been positively or negatively controlled. Citodur, glass ionomer or zinc oxide eugenol were inserted into the access cavity. All teeth were immersed for 9 days in India ink, then cleared and evaluated for dye penetration. Results. All groups of temporary restorations showed no significantly different marginal dye penetration. The glass ionomer cement presented the highest penetration. Conclusions. The restorative materials used could not stop dye penetration in the access cavity. They are not reliable for avoiding microleakage in root-filled teeth in case of long-term fillings.

  13. Assessment of fiber optic pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

    Hashemian, H.M.; Black, C.L.; Farmer, J.P. [Analysis and Measurement Services Corp., Knoxville, TN (United States)

    1995-04-01

    This report presents the results of a six-month Phase 1 study to establish the state-of-the-art in fiber optic pressure sensing and describes the design and principle of operation of various fiber optic pressure sensors. This study involved a literature review, contact with experts in the field, an industrial survey, a site visit to a fiber optic sensor manufacturer, and laboratory testing of a fiber optic pressure sensor. The laboratory work involved both static and dynamic performance tests. In addition, current requirements for environmental and seismic qualification of sensors for nuclear power plants were reviewed to determine the extent of the qualification tests that fiber optic pressure sensors may have to meet before they can be used in nuclear power plants. This project has concluded that fiber optic pressure sensors are still in the research and development stage and only a few manufacturers exist in the US and abroad which supply suitable fiber optic pressure sensors for industrial applications. Presently, fiber optic pressure sensors are mostly used in special applications for which conventional sensors are not able to meet the requirements.

  14. Micro-CT assessment of dentinal micro-cracks after root canal filling procedures.

    Science.gov (United States)

    De-Deus, G; Belladonna, F G; Silva, E J N L; Souza, E M; Carvalhal, J C A; Perez, R; Lopes, R T; Versiani, M A

    2017-09-01

    To evaluate the frequency of dentinal micro-cracks after root canal filling procedures with GuttaCore (GC), cold lateral compaction (CLC) and warm vertical compaction (WVC) techniques in mandibular molars using micro-computed tomographic analysis. Thirty mesial roots of mandibular molars, with a type II Vertucci's canal configuration, were prepared to working length with a Reciproc R40 instrument and randomly assigned to one of the three experimental groups (n = 10), according to the technique used for root filling: GC, CLC or WVC. The GC group was filled with a size 40 GC obturator, whilst CLC and WVC groups used conventional gutta-percha cones. AH Plus sealer was used in all groups. The specimens were scanned at an isotropic resolution of 14.25 μm before and after root canal preparation and after root filling. Then, all pre- and postoperative cross-sectional images of the roots (n = 41 660) were screened to identify the presence of dentinal defects. Overall, 30.75% (n = 12 810) of the pre- + post-filling images displayed dentinal defects. In the GC, CLC and WVC groups, dentinal micro-cracks were observed in 18.68% (n = 2510), 15.99% (n = 2389) and 11.34% (n = 1506) of the cross-sectional images, respectively. All micro-cracks identified in the post-filling scans were also observed in the corresponding post-preparation images. Root fillings in all techniques did not induce the development of new dentinal micro-cracks. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  15. Central arterial pressure assessment with intensity POF sensor

    Science.gov (United States)

    Leitão, Cátia; Gonçalves, Steve; Antunes, Paulo; Bastos, José M.; Pinto, João. L.; André, Paulo

    2015-09-01

    The central pressure monitoring is considered a new key factor in hypertension assessment and cardiovascular prevention. In this work, it is presented the central arterial systolic pressure assessment with an intensity based POF sensor. The device was tested in four subjects, and stable pulse waves were obtained, allowing the calculation of the central pressure for all the subjects. The results shown that the sensor performs reliably, being a simple and low-cost solution to the intended application.

  16. A New Approach to Plasma CVD of TiO2 Photocatalyst on γ-Al2O3 Pellet Filled in Dielectric Barrier Discharges at Atmospheric Pressure

    Science.gov (United States)

    Zhu, Aimin; Nie, Longhui; Zhang, Xiuling; Shi, Chuan; Song, Zhimin; Xu, Yong

    2004-12-01

    A supported TiO2/γ-Al2O3 photocatalyst has been prepared by γ-Al2O3 pellet-filled dielectric barrier discharges induced plasma CVD at atmospheric pressure and room temperature. The TiO2/γ-Al2O3 photocatalyst exhibits higher photocatalytic activity than Degussa P25, and much higher photocatalytic activity than that prepared by thermal CVD.

  17. A New Approach to Plasma CVD of TiO2 Photocatalyst on γ-Al2O3 Pellet Filled in Dielectric Barrier Discharges at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    朱爱民; 聂龙辉; 张秀玲; 石川; 宋志民; 徐勇

    2004-01-01

    A supported TiO2/γ-Al2O3 photocatalyst has been prepared by γ-Al2O3 pellet-filled dielectric barrier discharges induced plasma CVD at atmospheric pressure and room temperature.The TiO2/γ-Al2O3 photocatalyst exhibits higher photocatalytic activity than Degussa P25, and much higher photocatalytic activity than that prepared by thermal CVD.

  18. Investigations of structural, elastic, electronic and thermodynamic properties of lutetium filled skutterudite LuFe4P12 under pressure effect: FP-LMTO method

    Directory of Open Access Journals (Sweden)

    Boudia Keltouma

    2015-12-01

    Full Text Available Structural, elastic, electronic and thermodynamic properties of ternary cubic filled skutterudite compound were calculated. We have computed the elastic modulus and its pressure dependence. From the elastic parameter behavior, it is inferred that this compound is elastically stable and ductile in nature. Through the quasi-harmonic Debye model, in which phononic effects are considered, the effect of pressure P (0 to 50 GPa and temperature T (0 to 3000 °C on the lattice constant, elastic parameters, bulk modulus B, heat capacity, thermal expansion coefficient α, internal energy U, entropy S, Debye temperature θD, Helmholtz free energy A, and Gibbs free energy G are investigated.

  19. Reliability of assessing dye penetration along root canal fillings using methylene blue

    NARCIS (Netherlands)

    Souza, E.M.; Pappen, F.G.; Shemesh, H.; Bonato-Estrela, C.; Bonetti-Filho, I.

    2009-01-01

    Methylene blue (MB) remains the most frequently used tracer for dye penetration tests of endodontic fillings, despite its chemical reactions with different materials. This study checked whether dye penetration displayed by MB is comparable to Rhodamine B (RB). One hundred and seventy-two root canals

  20. Reliability of assessing dye penetration along root canal fillings using methylene blue

    NARCIS (Netherlands)

    Souza, E.M.; Pappen, F.G.; Shemesh, H.; Bonato-Estrela, C.; Bonetti-Filho, I.

    2009-01-01

    Methylene blue (MB) remains the most frequently used tracer for dye penetration tests of endodontic fillings, despite its chemical reactions with different materials. This study checked whether dye penetration displayed by MB is comparable to Rhodamine B (RB). One hundred and seventy-two root canals

  1. Impact of diastolic dysfunction severity on global left ventricular volumetric filling - assessment by automated segmentation of routine cine cardiovascular magnetic resonance

    Science.gov (United States)

    2010-01-01

    Objectives To examine relationships between severity of echocardiography (echo) -evidenced diastolic dysfunction (DD) and volumetric filling by automated processing of routine cine cardiovascular magnetic resonance (CMR). Background Cine-CMR provides high-resolution assessment of left ventricular (LV) chamber volumes. Automated segmentation (LV-METRIC) yields LV filling curves by segmenting all short-axis images across all temporal phases. This study used cine-CMR to assess filling changes that occur with progressive DD. Methods 115 post-MI patients underwent CMR and echo within 1 day. LV-METRIC yielded multiple diastolic indices - E:A ratio, peak filling rate (PFR), time to peak filling rate (TPFR), and diastolic volume recovery (DVR80 - proportion of diastole required to recover 80% stroke volume). Echo was the reference for DD. Results LV-METRIC successfully generated LV filling curves in all patients. CMR indices were reproducible (≤ 1% inter-reader differences) and required minimal processing time (175 ± 34 images/exam, 2:09 ± 0:51 minutes). CMR E:A ratio decreased with grade 1 and increased with grades 2-3 DD. Diastolic filling intervals, measured by DVR80 or TPFR, prolonged with grade 1 and shortened with grade 3 DD, paralleling echo deceleration time (p cine-CMR segmentation can discern LV filling changes that occur with increasing severity of echo-evidenced DD. Impaired relaxation is associated with prolonged filling intervals whereas restrictive filling is characterized by increased filling rates. PMID:20673372

  2. Educational assessment and teaching of older clients with pressure ulcers.

    Science.gov (United States)

    Ayello, E A; Mezey, M; Amella, E J

    1997-08-01

    The importance of education in preventing and treating patients with pressure ulcers is evident by the inclusion of recommendations for educational objectives in the clinical guidelines by the Agency for Health Care Policy and Research. Both caregiver and client should be assessed for knowledge of pressure ulcers. Physical changes in vision, hearing, and cognition that might affect educating older clients are described. Strategies suitable for teaching older clients about the prevention and treatment of pressure ulcers are given.

  3. Observational assessment and correlates to blood pressure of future ...

    African Journals Online (AJOL)

    Observational assessment and correlates to blood pressure of future ... of undiagnosed hypertension among undergraduate medical students and to ... Family history of hypertension or diabetes mellitus was not associated with hypertension.

  4. Do pressure ulcer risk assessment scales improve clinical practice?

    OpenAIRE

    Jan Kottner; Katrin Balzer

    2010-01-01

    Jan Kottner1, Katrin Balzer21Department of Nursing Science, Charité-Universitätsmedizin Berlin, Germany; 2Nursing Research Group, Institute for Social Medicine, Universitätsklinikum Schleswig-Holstein, Lübeck, GermanyAbstract: Standardized assessment instruments are deemed important for estimating pressure ulcer risk. Today, more than 40 so-called pressure ulcer risk assessment scales are available but still there is an ongoing debate about their usefulne...

  5. Do pressure ulcer risk assessment scales improve clinical practice?

    Directory of Open Access Journals (Sweden)

    Jan Kottner

    2010-07-01

    Full Text Available Jan Kottner1, Katrin Balzer21Department of Nursing Science, Charité-Universitätsmedizin Berlin, Germany; 2Nursing Research Group, Institute for Social Medicine, Universitätsklinikum Schleswig-Holstein, Lübeck, GermanyAbstract: Standardized assessment instruments are deemed important for estimating pressure ulcer risk. Today, more than 40 so-called pressure ulcer risk assessment scales are available but still there is an ongoing debate about their usefulness. From a measurement point of view pressure ulcer (PU risk assessment scales have serious limitations. Empirical evidence supporting the validity of PU risk assessment scale scores is weak and obtained scores contain varying amounts of measurement error. The concept of pressure ulcer risk is strongly related to the general health status and severity of illness. A clinical impact due do the application of these scales could also not be demonstrated. It is questionable whether completion of standardized pressure ulcer risk scales in clinical practice is really needed.Keywords: Braden pressure ulcer, prevention, risk assessment, nursing assessment, predictive value, clinical effectiveness, review

  6. Effect of fluid-filled support-surface utilization on prevention of pressure ulcers in the operating room: An experimental study

    Directory of Open Access Journals (Sweden)

    Şenay Gül

    2015-01-01

    Full Text Available Purpose: The aim of the study was to determine the effect of fluid-filled support-surface utilization on the prevention of pressure ulcers.Methods: A fluid-filled support surface was placed onto the operating table of patients in the experimental group (n: 30 whereas patients in the control group (n: 30 were treated on standard operating tables. The study was carried out between February 2011 and May 2011 in a university hospital. A total of 60 patients who underwent surgery in orthopedic and neurosurgery clinics were included in the study. The study was an experimental study.  Results: PUs were observed in only one patient (3.3% in the experimental group, they were observed in 15 patients (50% in the control group (p<0.05. All developing pressure ulcers were stage 1 PUs. A positive relationship was found between the development of pressure ulcers and the BPURAS score, and the duration of operation.Conclusions: We conclude that a support surface is beneficial when surgery lasts more than 4 hours and in patients whose preoperative risk score is high.

  7. Clustering-based limb identification for pressure ulcer risk assessment.

    Science.gov (United States)

    Baran Pouyan, M; Nourani, M; Pompeo, M

    2015-01-01

    Bedridden patients have a high risk of developing pressure ulcers. Risk assessment for pressure ulceration is critical for preventive care. For a reliable assessment, we need to identify and track the limbs continuously and accurately. In this paper, we propose a method to identify body limbs using a pressure mat. Three prevalent sleep postures (supine, left and right postures) are considered. Then, predefined number of limbs (body parts) are identified by applying Fuzzy C-Means (FCM) clustering on key attributes. We collected data from 10 adult subjects and achieved average accuracy of 93.2% for 10 limbs in supine and 7 limbs in left/right postures.

  8. SAPPIRE: a prototype mobile tool for pressure ulcer risk assessment.

    Science.gov (United States)

    Kim, Hyeoneui; Chung, Heejoon; Wang, Shuang; Jiang, Xiaoqian; Choi, Jeeyae

    2014-01-01

    Accurate assessment and documentation of skin conditions facilitate communication among care providers and are critical to effective prevention and mitigation of pressure ulcer. We report developing a prototype mobile system called SAPPIRE (Skin Assessment for Pressure Ulcer Prevention, an Integrated Recording Environment) for an android device to assist nurses with skin assessment and documentation at bedside. SAPPIRE demonstrates (1) data documentation conforming to the relevant terminology standards, (2) data exchange using Continuity of Care Records (CCR) standard and (3) smart display of patient data relevant to risk parameters to promote accurate pressure ulcer risk assessment with the Braden scale. Challenges associated standardizing assessment data faced during this development and the approaches that SAPPIRE took to overcome them are described.

  9. Development of an Integrity Assessment Procedure for CANDU Pressure Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Han Sub [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    The pressure tubes used in a CANDU reactor are made from Zr-2.5Nb. During service the pressure tubes operate at temperatures between about 150 and 310 .deg. C, and with variable coolant pressures up to 11MPa corresponding to hoop stress of up to 130MPa. The maximum flux of fast neutrons (E>1MeV) from the fuel is about 4X10{sup 17}nm{sup -2}{sub s}{sup -1}. The pressure tubes are exposed to very severe degradation environment. The aging degradation of the pressure tubes are summarized as below. - Geometric deformation; axial elongation, diametric creep, and wall thinning. - Deuterium uptake; some fraction of the deuterium generated by the corrosion of pressure tubes is absorbed into the pressure tubes. Total equivalent hydrogen content in the pressure tube is the sum of the initial hydrogen content before operation and the deuterium uptake during operation. High concentration of hydrogen inside the pressure tubes makes the metal susceptible to Delayed Hydride Cracking. The DHC is a degradation mechanism of prime importance for CANDU pressure tubes. Mechanical properties, in particular fracture toughness, are deteriorated by high concentration of dissolved hydrogen. - Flaws; volumetric flaws are generated during operation. Wear scars by debris fretting, and bearing pad fretting are common. These volumetric flaws can be a site of crack initiation by fatigue or DHC. Cracks can propagate by DHC or fatigue crack propagation if conditions are met. - Material properties degradation; mechanical properties are affected by neutron irradiation. Yield strength and tensile strength are increased, and fracture toughness is deteriorated. The susceptibility to DHC is also affected. The integrity assessment of the pressure tube is a procedure to determine if the risk of pressure tube failure is controlled to maintain acceptably low. CSA N285.4 and 285.8 are two important guidelines regarding the integrity of pressure tubes. N285.4 is to guide in-service inspection, and N285

  10. Electrolytic installation in order to obtain deuterium and to fill the pressure deposits; Instalacion electrolitica para la obtencion de deuterio y llenado de depositos a preseion

    Energy Technology Data Exchange (ETDEWEB)

    Cordero Lopez, F.; Tanarro Sanz, A.

    1959-07-01

    In order to obtain deuterium to feed the ion sources of the accelerators an easy and automatic electrolytic installation has been prepared. this installation and a small compressor designed and constructed for this purpose permit to fill deposits of 1 or 2 liters capacity with deuterium, till a 4 atmosphere pressure in few hours of operation. The electrolytic cell has V shape and permits operation with 3 cc heavy water only as it has small dead volume; the electrodes are platinum and as electrolyte an OH Na solution in a proportion of 15 w/o is used. (Author) 3 refs.

  11. An Assessment of Reservoir Filling Policies under a Changing Climate for Ethiopia's Grand Renaissance Dam

    Science.gov (United States)

    King, A.; Block, P. J.

    2012-12-01

    Climate variability and change cause unsteady hydrologic response, commonly experienced through varying river flows. These variations affect the performance and reliability of water resources dependent systems, including domestic, agriculture, energy, and the environment, with economic implications. Long-term design and operation of these systems is therefore inherently uncertain, producing copious risks at time-scales of months to decades. Yet evaluation of system performance under non-stationary climate conditions is typically ignored. Here we demonstrate the potential performance of Ethiopia's forthcoming Grand Renaissance hydropower dam on the Blue Nile River, subject to coincident climate change and reservoir filling policies. Presently, no agreed-upon reservoir retention policy exists between Ethiopia and downstream countries, even though construction has already begun. We will present a tool designed to allow users to select expected future climate conditions and reservoir filling rates, from a stochastic perspective. Additionally, the maximum reservoir volume may also be varied. Major outputs include hydropower generation and downstream flow for use by policy-makers. Ethiopia's desire to rapidly expand hydropower dams on the Nile constitutes an enormous financial investment and latent risk, with further implications on streamflow reduction to Sudan and Egypt, and a need for multi-national energy contracts, necessitating proper advanced planning.

  12. Standard practice for examination of Gas-Filled filament-wound composite pressure vessels using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice provides guidelines for acoustic emission (AE) examination of filament-wound composite pressure vessels, for example, the type used for fuel tanks in vehicles which use natural gas fuel. 1.2 This practice requires pressurization to a level equal to or greater than what is encountered in normal use. The tanks' pressurization history must be known in order to use this practice. Pressurization medium may be gas or liquid. 1.3 This practice is limited to vessels designed for less than 690 bar [10,000 psi] maximum allowable working pressure and water volume less than 1 m3 or 1000 L [35.4 ft3]. 1.4 AE measurements are used to detect emission sources. Other nondestructive examination (NDE) methods may be used to gain additional insight into the emission source. Procedures for other NDE methods are beyond the scope of this practice. 1.5 This practice applies to examination of new and in-service filament-wound composite pressure vessels. 1.6 This practice applies to examinations conducted at amb...

  13. Risk assessment scales for pressure ulcer prevention: a systematic review.

    Science.gov (United States)

    Pancorbo-Hidalgo, Pedro L; Garcia-Fernandez, Francisco Pedro; Lopez-Medina, Isabel Ma; Alvarez-Nieto, Carmen

    2006-04-01

    This paper reports a systematic review conducted to determine the effectiveness of the use of risk assessment scales for pressure ulcer prevention in clinical practice, degree of validation of risk assessment scales, and effectiveness of risk assessment scales as indicators of risk of developing a pressure ulcer. Pressure ulcers are an important health problem. The best strategy to avoid them is prevention. There are several risk assessment scales for pressure ulcer prevention which complement nurses' clinical judgement. However, some of these have not undergone proper validation. A systematic bibliographical review was conducted, based on a search of 14 databases in four languages using the keywords pressure ulcer or pressure sore or decubitus ulcer and risk assessment. Reports of clinical trials or prospective studies of validation were included in the review. Thirty-three studies were included in the review, three on clinical effectiveness and the rest on scale validation. There is no decrease in pressure ulcer incidence was found which might be attributed to use of an assessment scale. However, the use of scales increases the intensity and effectiveness of prevention interventions. The Braden Scale shows optimal validation and the best sensitivity/specificity balance (57.1%/67.5%, respectively); its score is a good pressure ulcer risk predictor (odds ratio = 4.08, CI 95% = 2.56-6.48). The Norton Scale has reasonable scores for sensitivity (46.8%), specificity (61.8%) and risk prediction (OR = 2.16, CI 95% = 1.03-4.54). The Waterlow Scale offers a high sensitivity score (82.4%), but low specificity (27.4%); with a good risk prediction score (OR = 2.05, CI 95% = 1.11-3.76). Nurses' clinical judgement (only considered in three studies) gives moderate scores for sensitivity (50.6%) and specificity (60.1%), but is not a good pressure ulcer risk predictor (OR = 1.69, CI 95% = 0.76-3.75). There is no evidence that the use of risk assessment scales decreases pressure

  14. Synergistic Assessment of Sustained Casing Pressure on Oil Well

    Directory of Open Access Journals (Sweden)

    Darren Wong Vun Nyap

    2013-05-01

    Full Text Available The current research is based on modeling approach, where the objective is to develop a series of computer codes with the reference of existing pressure bleed-off time mathematical models. The results generated from the model are based on the three parameters: temperature, type of gases filled in annulus and depth of well. These three parameters can affect pressure bleed-off time in well’s annulus, with the fixed size of needle valve. Using this model generated from Wolfram Mathematical 8.0, it is enable to notify engineer to receive an early sign of warning if the well is suspected to leakage. Meanwhile, based on the matching process of field data and modeled data, field engineers will be able to aware and determine whether the occurrence of annular pressure is due to thermal induced annular pressure buildup or it is because of leakage in well components. The SCP well will eventually loss in production, caused severe failure in well’s integrity.

  15. Influence of pressure conditions and back-filling materials on the durability of bore-hole ground loops; Lebensdauer von Erdwaermesonden in Bezug auf Druckverhaeltnisse und Hinterfuellung

    Energy Technology Data Exchange (ETDEWEB)

    Rohner, R. [E. Rohner, Arnegg (Switzerland); Rybach, L.; Salton, M. [Swiss Federal Institute of Technology (ETHZ), Institut fuer Geophysik, Zuerich (Switzerland)

    2001-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) discusses the influence of the relatively high pressures found in ground loops at depths of more than 200 metres and the effects caused by overloading the ground loops. The latter can cause the back-filling between the ground loop and the surrounding rock to freeze. The report describes tests carried out on 70-metre and 265-metre deep test bore-hole installations. The results of investigations into the influence of such pressure conditions on the materials of the ground loop and their service life are presented. The results are also compared with simulations using the FRACTure and EED calculation programmes. Details are given on the bore-holes with respect to their geology and construction. The report concludes that bore-hole ground loops can be considered as being very robust components with a long service life, provided they are designed and installed according to accepted professional standards.

  16. Designing trials for pressure ulcer risk assessment research: methodological challenges.

    Science.gov (United States)

    Balzer, K; Köpke, S; Lühmann, D; Haastert, B; Kottner, J; Meyer, G

    2013-08-01

    For decades various pressure ulcer risk assessment scales (PURAS) have been developed and implemented into nursing practice despite uncertainty whether use of these tools helps to prevent pressure ulcers. According to current methodological standards, randomised controlled trials (RCTs) are required to conclusively determine the clinical efficacy and safety of this risk assessment strategy. In these trials, PURAS-aided risk assessment has to be compared to nurses' clinical judgment alone in terms of its impact on pressure ulcer incidence and adverse outcomes. However, RCTs evaluating diagnostic procedures are prone to specific risks of bias and threats to the statistical power which may challenge their validity and feasibility. This discussion paper critically reflects on the rigour and feasibility of experimental research needed to substantiate the clinical efficacy of PURAS-aided risk assessment. Based on reflections of the methodological literature, a critical appraisal of available trials on this subject and an analysis of a protocol developed for a methodologically robust cluster-RCT, this paper arrives at the following conclusions: First, available trials do not provide reliable estimates of the impact of PURAS-aided risk assessment on pressure ulcer incidence compared to nurses' clinical judgement alone due to serious risks of bias and insufficient sample size. Second, it seems infeasible to assess this impact by means of rigorous experimental studies since sample size would become extremely high if likely threats to validity and power are properly taken into account. Third, means of evidence linkages seem to currently be the most promising approaches for evaluating the clinical efficacy and safety of PURAS-aided risk assessment. With this kind of secondary research, the downstream effect of use of PURAS on pressure ulcer incidence could be modelled by combining best available evidence for single parts of this pathway. However, to yield reliable modelling

  17. Part 2: pressure ulcer assessment: implementation and revision of CALCULATE.

    Science.gov (United States)

    Richardson, Annette; Straughan, Christine

    2015-11-01

    Critically ill patients are a vulnerable group at very high risk of developing pressure ulcers, and the incidence varies within critical care. A number of strategies were used to implement the pressure ulcer assessment tool CALCULATE across four adult critical care units. Strategies included, nursing leadership, the provision of definitions for each risk factor, information laid out on posters at each patient's bedside, changes to pre-printed nursing documentation and a 30-min focused training package. Two local audits were conducted to measure the number and types of risk factors occurring in patients with pressure ulcers, and to assess the frequency of assessments and gain feedback on the usability of the tool in practice. Critical care acquired pressure ulcer incidence was 3.4%. The two most commonly occurring risk factors were impaired circulation (82%) and mechanical ventilation (75%). Patients had a mean score of 4, and 65% had 4 or more reported risk factors. Feedback on the usability of the tool was mainly positive. The tool CALCULATE was relatively straightforward to implement and was likely to be due to the design and the various change strategies used to implement the new approach. The seven point tool was revised to an eight point score based on nurses' clinical feedback. Research is required to further enhance and develop pressure ulcer assessment. Meanwhile CALCULATE offers an easy to use and appropriate tool to assist in the identification of patients at an elevated risk of pressure ulcer damage. Careful choice of change management strategies are needed when implementing a new assessment tool. CALCULATE should be considered for use in critical care for pressure ulcer assessment, but used alongside nurses' clinical judgement and observations of skin. © 2015 British Association of Critical Care Nurses.

  18. Effect of Melt Temperature and Hold Pressure on the Weld-Line Strength of an Injection Molded Talc-Filled Polypropylene

    Directory of Open Access Journals (Sweden)

    Yuanxin Zhou

    2014-01-01

    Full Text Available Tensile stress-strain behavior coupled with fractography was used to investigate the weld-line strength of an injection molded 40 w% talc-filled polypropylene. The relationship between processing conditions, microstructure, and tensile strength was established. Fracture surface of the weld line exhibited skin-core morphology with different degrees of talc particle orientations in the core and in the skin. Experimental results also showed that the thickness of the core decreased and the thickness of the skins increased with increasing melt temperature and increasing hold pressure, which resulted in an increase of yield strength and yield strain with increasing melt temperature and increasing hold pressure. Finally, a three-parameter nonlinear constitutive model was developed to describe the strain softening behavior of the weld-line strength of talc-filled polypropylene. The parameters in this model are the modulus E, the strain exponent m, and the compliance factor β. The simulated stress-strain curves from the model are in good agreement with the test data, and both m and β are functions of skin-core thickness ratio.

  19. Cognitive and literacy screening as predictors of ability to fill a pillbox using two pillbox assessment scoring methods.

    Science.gov (United States)

    Anderson, Kitty; Willmore, Catherine; Doran, Elizabeth; Oki, Naoto; Vonnahme, Joel; Gates, Brian J

    2014-01-01

    To compare patient cognition measured by Medi-Cog, a tool to assess cognitive literacy and pillbox skills, with pillbox concordance using two scoring methods, Pillbox Fill (PBF) and Prospective Pill Count (PPC). Prospective, descriptive, cross-sectional study. Primary care. Multiethnic participants with type 2 diabetes with sufficient vision and dexterity to load a pillbox. Medi-Cog scores were correlated with ability to fill a pillbox based on both the PPC and the PBF scoring methods. Variables were analyzed by multivariate linear and logistic regression. To determine whether there is a difference between PBF and PPC scoring methods relative to Medi-Cog prediction of pillbox concordance. Sixty-four participants loaded an average of 5.2 medications. Mean Medi-Cog score for five patients who failed PBF but passed PPC were lower than the entire cohort (5.6 compared with 6.2). Correlation between PBF and PPC methods was 0.978; P = 0.01. Regression values for Medi-Cog's ability to predict PBF and PPC scores were r = 0.668 and r2 = 0.446, and r = 0.660 and r2 = 0.436; P assessments as well as cognitive screening prior to recommending pillbox use.

  20. Standard practice for examination of liquid-Filled atmospheric and Low-pressure metal storage tanks using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers guidelines for acoustic emission (AE) examinations of new and in-service aboveground storage tanks of the type used for storage of liquids. 1.2 This practice will detect acoustic emission in areas of sensor coverage that are stressed during the course of the examination. For flat-bottom tanks these areas will generally include the sidewalls (and roof if pressure is applied above the liquid level). The examination may not detect flaws on the bottom of flat-bottom tanks unless sensors are located on the bottom. 1.3 This practice may require that the tank experience a load that is greater than that encountered in normal use. The normal contents of the tank can usually be used for applying this load. 1.4 This practice is not valid for tanks that will be operated at a pressure greater than the examination pressure. 1.5 It is not necessary to drain or clean the tank before performing this examination. 1.6 This practice applies to tanks made of carbon steel, stainless steel, aluminum and oth...

  1. Accuracy of Ceramic Mould Filling with Liquid AlSi9 Aluminium Alloy in the Process Using Back-pressure

    Directory of Open Access Journals (Sweden)

    A. Karwiński

    2013-01-01

    Full Text Available The paper presents the effect of suction pressure exerted on the liquid AlSi alloy when it is introduced into a ceramic mould made in the investment process and the results compared with data obtained on gravity poured castings.The study used special pattern sets and ceramic moulds made with the alternately applied soluble silicate binder and ethyl silicate.Additionally, self-supported moulds based entirely on the Ekosil binder were used. In the analysis of castings, the following parameters were examined: a linear dimensional accuracy, the state of surface microgeometry and the possibility of metal penetration into a complex ceramic mould, allowing also for the presence of capillary phenomena. In the process of casting with back-pressure, the pressure values of 500 hPa, 600 hPa and 700 hPa were applied in the chamber where the ceramic mould was located, with the temperature of the said mould kept at a level of 150  10C.

  2. Correlation of Global Strain Rate and Left Ventricular Filling Pressure in Patients with Coronary Artery Disease: A 2-D Speckle-Tracking Study.

    Science.gov (United States)

    Ma, Hong; Wu, Wei-Chun; Xie, Rong-Ai; Gao, Li-Jian; Wang, Hao

    2016-02-01

    The aim of the present study was to evaluate the role of 2-D speckle-tracking imaging in the prediction of left ventricular filling pressure in patients with coronary artery disease (CAD) and normal left ventricular ejection fraction (LVEF). Eighty-four patients with CAD and 30 healthy controls were recruited prospectively. The longitudinal strain rate (SR) curves were determined in three apical views of the left ventricle long axis. Circumferential and radial SR curves were determined in three short-axis views. Left ventricular end-diastolic pressure (LVEDP) was invasively obtained by left heart catheterization. Compared with the 30 controls, the patients with CAD had significantly lower global SR during early diastole (SRe) and higher E/SRe in three directions of myocardial deformation. CAD patients with elevated LVEDP had significantly lower SRe and higher E/SRe of three deformations. Pearson's correlation analysis revealed that LVEDP correlated positively with E/E' ratio, radial SRe and longitudinal and circumferential E/SRe. LVEDP correlated negatively with longitudinal and circumferential SRe and radial E/SRe. Receiver operating characteristic curve analysis revealed that these SR indexes predicted elevated LVEDP (areas under the curve: longitudinal E/SRe = 0.74, circumferential E/SRe = 0.74, circumferential SRe = 0.70, longitudinal SRe = 0.69, radial E/SRe = 0.68, radial SRe = 0.65), but neither was superior to the tissue Doppler imaging index E/E' (area under the curve = 0.84). The present study indicates that 2-D speckle-tracking imaging is a practical method for evaluating LV filling pressure, but it might not provide additional advantages compared with E/E' in CAD patients.

  3. The structural, transport, and magnetic properties of Yb-filled skutterudites YbyFexCo4-xSb12 synthesized under high pressure

    Science.gov (United States)

    Chen, Yuqi; Kawamura, Yukihiro; Hayashi, Junichi; Takeda, Keiki; Sekine, Chihiro

    2016-12-01

    The effects of Fe-substitution on partially Yb filled skutterudites YbyFexCo4-xSb12 are presented from the viewpoint of crystal structure and thermoelectric, magnetic, and transport properties. A series of polycrystalline n-type YbyFexCo4-xSb12 (0.21 ≤ y ≤ 0.47, 0 ≤ x ≤ 0.76) samples were prepared using a high-pressure and high-temperature method. X-ray diffraction data suggest that all the compounds are high-purity skutterudites. For the YbyFexCo4-xSb12 with Yb content higher than 0.29 and Fe content lower than 1, the lattice constant shows a saturated behavior despite the change in the Yb/Fe content. Rietveld refinement based on the synchrotron radiation X-ray data implies that the rectangular Sb4 ring is transformed into square with increasing Yb content and/or Fe substitution content. The Yb valence gradually decreases as the Fe content increases from magnetic susceptibility analysis. According to the specific heat analysis, higher Yb filling benefits the lower Debye temperature while the Fe substitution leads to an increased Debye temperature. The Einstein temperature decreased with increasing Yb filling fraction, but Fe substitution for the Co site does not change the Einstein temperature further. Fe-substitution causes the reduction of total thermal conductivity κ, which mainly originates from the decrease of electron thermal conductivity contribution. The resistivity, Seebeck coefficient, thermal conductivity, and figure of merit (ZT) were effectively tuned due to the optimization of the carrier concentration. At the same carrier concentration, the hall mobility was decreased by Fe substitution. The proper Fe substitution content (0.2 in Yb0.25Fe0.2Co3.8Sb12) can result in a relatively high effective mass.

  4. Semi-automatic detection of Gd-DTPA-saline filled capsules for colonic transit time assessment in MRI

    Science.gov (United States)

    Harrer, Christian; Kirchhoff, Sonja; Keil, Andreas; Kirchhoff, Chlodwig; Mussack, Thomas; Lienemann, Andreas; Reiser, Maximilian; Navab, Nassir

    2008-03-01

    Functional gastrointestinal disorders result in a significant number of consultations in primary care facilities. Chronic constipation and diarrhea are regarded as two of the most common diseases affecting between 2% and 27% of the population in western countries 1-3. Defecatory disorders are most commonly due to dysfunction of the pelvic floor or the anal sphincter. Although an exact differentiation of these pathologies is essential for adequate therapy, diagnosis is still only based on a clinical evaluation1. Regarding quantification of constipation only the ingestion of radio-opaque markers or radioactive isotopes and the consecutive assessment of colonic transit time using X-ray or scintigraphy, respectively, has been feasible in clinical settings 4-8. However, these approaches have several drawbacks such as involving rather inconvenient, time consuming examinations and exposing the patient to ionizing radiation. Therefore, conventional assessment of colonic transit time has not been widely used. Most recently a new technique for the assessment of colonic transit time using MRI and MR-contrast media filled capsules has been introduced 9. However, due to numerous examination dates per patient and corresponding datasets with many images, the evaluation of the image data is relatively time-consuming. The aim of our study was to develop a computer tool to facilitate the detection of the capsules in MRI datasets and thus to shorten the evaluation time. We present a semi-automatic tool which provides an intensity, size 10, and shape-based 11,12 detection of ingested Gd-DTPA-saline filled capsules. After an automatic pre-classification, radiologists may easily correct the results using the application-specific user interface, therefore decreasing the evaluation time significantly.

  5. Transport properties of the filled skutterudite Pr{sub x}Fe{sub 4}Sb{sub 12} synthesized under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kenya [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)], E-mail: tanaka-kenya@ed.tmu.ac.jp; Kikuchi, Daisuke; Kawahito, Yusuke; Ueda, Makoto; Aoki, Hidekazu; Kuwahara, Keitaro [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Sugawara, Hitoshi [Faculty of Integrated Arts and Science, The University of Tokushima, Tokushima 770-8502 (Japan); Aoki, Yuji; Sato, Hideyuki [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)

    2008-04-01

    We have investigated the thermoelectric power (S), Hall coefficient (R{sub H}), and magnetoresistance (MR) of Pr{sub x}Fe{sub 4}Sb{sub 12} (x{approx}1) synthesized under high pressure. The dependence of S and R{sub H} on the Pr-site filling fraction x become apparent at low temperatures. In MR, we confirmed that the electrical resistivity is enhanced by the 4f-electron crystalline electric field effect below {approx}10K and suppressed by the 3d-electron spin fluctuation effect above {approx}10K. The change of magnetic state in Pr{sub x}Fe{sub 4}Sb{sub 12} with x, realized as a combined effect of 4f-electrons and the high electronic density of state at Fermi level, is well reflected in the transport properties.

  6. In-situ biofouling assessment in spacer filled channels using optical coherence tomography (OCT): 3D biofilm thickness mapping

    KAUST Repository

    Fortunato, Luca

    2017-01-13

    Membrane systems for water purification can be seriously hampered by biofouling. The use of optical coherence tomography (OCT) to investigate biofilms in membrane systems has recently increased due to the ability to do the characterization in-situ and non-destructively The OCT biofilm thickness map is presented for the first time as a tool to assess biofilm spatial distribution on a surface. The map allows the visualization and evaluation of the biofilm formation and growth in membrane filtration systems through the use of a false color scale. The biofilm development was monitored with OCT to evaluate the suitability of the proposed approach. A 3D time series analysis of biofilm development in a spacer filled channel representative of a spiral-wound membrane element was performed. The biofilm thickness map enables the time-resolved and spatial-resolved evaluation and visualization of the biofilm deposition pattern in-situ non-destructively.

  7. A new technique for assessing arterial pressure wave forms and central pressure with tissue Doppler

    Science.gov (United States)

    Haluska, Brian A; Jeffriess, Leanne; Mottram, Phillip M; Carlier, Stephane G; Marwick, Thomas H

    2007-01-01

    Background Non-invasive assessment of arterial pressure wave forms using applanation tonometry of the radial or carotid arteries can be technically challenging and has not found wide clinical application. 2D imaging of the common carotid arteries is routinely used and we sought to determine whether arterial waveform measurements could be derived from tissue Doppler imaging (TDI) of the carotid artery. Methods We studied 91 subjects (52 men, age 52 ± 14 years) with and without cardiovascular disease. Tonometry was performed on the carotid artery simultaneously with pulsed wave Doppler of the LVOT and acquired digitally. Longitudinal 2D images of the common carotid artery with and without TDI were also acquired digitally and both TDI and tonometry were calibrated using mean and diastolic cuff pressure and analysed off line. Results Correlation between central pressure by TDI and tonometry was excellent for maximum pressure (r = 0.97, p < 0.0001). The mean differences between central pressures derived by TDI and tonometry were minimal (systolic 5.36 ± 5.5 mmHg; diastolic 1.2 ± 1.2 mmHg). Conclusion Imaging of the common carotid artery motion with tissue Doppler may permit acquisition of a waveform analogous to that from tonometry. This method may simplify estimation of central arterial pressure and calculation of total arterial compliance. PMID:17266772

  8. Performance assessment of an inline horizontal swirl tube cyclone for gas-liquid separation at high pressure

    Institute of Scientific and Technical Information of China (English)

    Nurhayati Mellon; Azmi M. Shariff

    2011-01-01

    The application of swirl tube cyclone for gas-liquid separation is attractive due to its small size and weight.However,very scarce information on the performance of the swirl tube cyclone especially at high operating pressure emulating actual field condition was published in journals.Performance assessment was usually done at a low operating pressure using either air-water,air-fine particle mixtures or dense gas such as SF6.This paper fills the existing gaps and reports the initial findings on the performance assessment of a horizontal swirl tube cyclone for gas-liquid separation operating at a flow rate of 5 MMSCFD at 40-60 bar operating pressure.

  9. Pressure assessment in intercavernous embedding of bulboperineal urethra for treatment of urinary incontinence after prostatic operation

    Institute of Scientific and Technical Information of China (English)

    Li-Xin QIAN; Hong-Fei WU; Yuan-Geng SHUI; Wei ZHANG; Shuang-Guan CHENG; Min GU; Zheng-Quan XU

    2001-01-01

    Aim: To put forward criteria for the pressure assessment in the operation of intercavemous embedding of bulboperineal urethra for the treatment of urinary incontinence after prostatic operation. Methods: A Fl4 urethral catheter is inserted during the operation and upon suturing the corpora cavemosa centrally, the catheter is slowly pushed in and pulled out in order that the operator feels a certain degree of close-fit resistance. The degree of tightness of the stitches,which regulate the compression pressure, is adjusted in accordance with this close-fit sensation. To further ascertain the adequacy of the force of compression, the bladder is filled with 300 ml physiological saline and observe the appropriateness (size and continuity) of the outflow stream when the lower abdomen is depressed with a pressure of 80-90 cm H2O. The operation was given to six patients suffered from urinary incontinence for 20 or more months after prostatic operation. Results: Five cases achieved complete recovery, while the therapeutic effect of the 6th one was not satisfactory. A second stage operation was carried out 3 months later with the addition of one more stitch both proximally and distally to reinforce the compression force. The condition was improved dramatically. The follow-up period averaged 3.5 years. Conclusion: The adequacy of the compression pressure exerted by the juxtaposed corpora cavernosa is the key point determining the outcome of the operation. The measures for assessing the compression pressure suggested by the authors are helpful in obtaining the good results of the present paper (6/6 success) as compared with 25/34success in the previous report.

  10. Impact of diastolic dysfunction severity on global left ventricular volumetric filling - assessment by automated segmentation of routine cine cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Mendoza Dorinna D

    2010-07-01

    Full Text Available Abstract Objectives To examine relationships between severity of echocardiography (echo -evidenced diastolic dysfunction (DD and volumetric filling by automated processing of routine cine cardiovascular magnetic resonance (CMR. Background Cine-CMR provides high-resolution assessment of left ventricular (LV chamber volumes. Automated segmentation (LV-METRIC yields LV filling curves by segmenting all short-axis images across all temporal phases. This study used cine-CMR to assess filling changes that occur with progressive DD. Methods 115 post-MI patients underwent CMR and echo within 1 day. LV-METRIC yielded multiple diastolic indices - E:A ratio, peak filling rate (PFR, time to peak filling rate (TPFR, and diastolic volume recovery (DVR80 - proportion of diastole required to recover 80% stroke volume. Echo was the reference for DD. Results LV-METRIC successfully generated LV filling curves in all patients. CMR indices were reproducible (≤ 1% inter-reader differences and required minimal processing time (175 ± 34 images/exam, 2:09 ± 0:51 minutes. CMR E:A ratio decreased with grade 1 and increased with grades 2-3 DD. Diastolic filling intervals, measured by DVR80 or TPFR, prolonged with grade 1 and shortened with grade 3 DD, paralleling echo deceleration time (p 80 identified 71% of patients with echo-evidenced grade 1 but no patients with grade 3 DD, and stroke-volume adjusted PFR identified 67% with grade 3 but none with grade 1 DD (matched specificity = 83%. The combination of DVR80 and PFR identified 53% of patients with grade 2 DD. Prolonged DVR80 was associated with grade 1 (OR 2.79, CI 1.65-4.05, p = 0.001 with a similar trend for grade 2 (OR 1.35, CI 0.98-1.74, p = 0.06, whereas high PFR was associated with grade 3 (OR 1.14, CI 1.02-1.25, p = 0.02 DD. Conclusions Automated cine-CMR segmentation can discern LV filling changes that occur with increasing severity of echo-evidenced DD. Impaired relaxation is associated with prolonged

  11. First third filling parameters of left ventricle assessed from gated equilibrium studies in patients with various heart diseases

    Energy Technology Data Exchange (ETDEWEB)

    Adatepe, M.H.; Nichols, K.; Powell, O.M.; Isaacs, G.H.

    1984-01-01

    The authors determined the first third filling fraction (1/3 FF), the maximum filling rate (1/3 FR) and the mean filling rate (1/3 MFR) for the first third diastolic filling period of the left ventricle in patients with coronary artery disease (CAD), valvular heart disease (VHD), pericardial effusion (PE), cardiomyopathies (CM), chronic obstructive lung disease (COPD) and in 5 normals-all from resting gated equilibrium studies. Parameters are calculated from the third order Fourier fit to the LV volume curve and its derivative. 1/3 FF% = 1/3 diastolic count - end systolic count / 1/3 diastolic count x 100. Patients with CAD are divided into two groups: Group I with normal ejection fraction (EF) and wall motion (WM); Group II with abnormal EF and WM. Results are shown in the table. Abnormal filling parameters are found not only in CAD but in VHD, PE and CM. The authors conclude that the first third LV filling parameters are sensitive but non-specific indicators of filling abnormalities caused by diverse etiologic factors. Abnormal first third filling parameters may occur in the presence of a normal resting EF and WM in CAD.

  12. Assessment of sacrococcygeal pressure ulcers using diffuse correlation spectroscopy

    Science.gov (United States)

    Diaz, David; Lafontant, Alec; Neidrauer, Michael; Weingarten, Michael S.; DiMaria-Ghalili, Rose Ann; Fried, Guy W.; Rece, Julianne; Lewin, Peter A.; Zubkov, Leonid

    2016-03-01

    Microcirculation is essential for proper supply of oxygen and nutritive substances to the biological tissue and the removal of waste products of metabolism. The determination of microcirculatory blood flow (mBF) is therefore of substantial interest to clinicians for assessing tissue health; particularly in pressure ulceration and suspected deep tissue injury. The goal of this pilot clinical study was to assess deep-tissue pressure ulceration by non-invasively measuring mBF using Diffuse Correlation Spectroscopy (DCS). DCS provides information about the flow of red blood cells in the capillary network by measuring the temporal autocorrelation function of scattering light intensity. A novel optical probe was developed in order to obtain measurements under the load of the subject's body as pressure is applied (ischemia) and then released (reperfusion) on sacrococcygeal tissue in a hospital bed. Prior to loading measurements, baseline readings of the sacral region were obtained by measuring the subjects in a side-lying position. DCS measurements from the sacral region of twenty healthy volunteers have been compared to those of two patients who initially had similar non-blanchable redness. The temporal autocorrelation function of scattering light intensity of the patient whose redness later disappeared was similar to that of the average healthy subject. The second patient, whose redness developed into an advanced pressure ulcer two weeks later, had a substantial decrease in blood flow while under the loading position compared to healthy subjects. Preliminary results suggest the developed system may potentially predict whether non-blanchable redness will manifest itself as advanced ulceration or dissipate over time.

  13. Recent Research Advances in the Risk Assessment Method of an Underground Pressure Pipeline

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper reviews the risk assessment method of an underground pressure pipeline, introduces the risk assessment method of expert grading, fuzzy integrative assessment, probabilistic risk assessment and extenics assessment in an underground pressure pipeline. Moreover, it puts forward the developing orientation of risk assessment.

  14. [Assessment of pain in a patient with pressure ulcer].

    Science.gov (United States)

    Píriz-Campos, Rosa María; Martín-Espinosa, Noelia María; Cobo-Cuenca, Ana Isabel

    2010-01-01

    This is a summary of a presentation made in the symposium "Improved Continuous Quality Care in Patients with Pressure Ulcers and Chronic Injuries", which was held in Toledo in 2009. A 76 year old woman had been assessed (she belonged to the age group that frequently suffers this condition). She lived in a social healthcare centre and had a III stage sacral pressure ulcer. Using Gordon's Functional Health Patterns for assessing "Acute pain", a nursing diagnosis is described and the nursing care plan has been presented according to NANDA, NIC, NOC taxonomy. The aim of this article is to show the importance of considering the pain in patients who suffer from this type of lesion, which, although almost always present, it is often undervalued by nursing staff, resulting in an even worse quality of life for the patient, due to both physical and psychological effects. This case shows how to assess pain in a patient with ulcers, and helps establish an individualised care plan with a priority on pain treatment and relief. As as result of the interventions carried out, a better perception of pain is achieved, thus helping to improve patient's mobility and night rest.

  15. The deterministic structural integrity assessment of reactor pressure vessels under pressurized thermal shock loading

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mingya, E-mail: chenmingya@cgnpc.com.cn; Lu, Feng; Wang, Rongshan; Huang, Ping; Liu, Xiangbin; Zhang, Guodong; Xu, Chaoliang

    2015-07-15

    Highlights: • The conservative and non-conservative assumptions in the codes were shown. • The influence of different loads on the SM was given. • The unloading effect of the cladding was studied. • A concentrated reflection of the safety was shown based on 3-D FE analyses. - Abstract: The deterministic structural integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs) has been extensively studied. While the nil-ductility-transition temperature (RT{sub NDT}) parameter is widely used, the influence of fluence and temperature distributions along the thickness of the base metal wall cannot be reflected in the comparative analysis. This paper introduces the method using a structure safety margin (SM) parameter which is based on a comparison between the material toughness (the fracture initiation toughness K{sub IC} or fracture arrest toughness K{sub Ia}) and the stress intensity factor (SIF) along the crack front for the integrity analysis of a RPV subjected to PTS transients. A 3-D finite element model is used to perform fracture mechanics analyses considering both crack initiation assessment and arrest assessment. The results show that the critical part along the crack front is always the clad-base metal interface point (IP) rather than the deepest point (DP) for either crack initiation assessment or crack arrest assessment under the thermal load. It is shown that the requirement in Regulatory Guide 1.154 that ‘axial flaws with depths less than 20% of the wall thickness and all circumferential flaws should be modeled in infinite length’ may be non-conservative. As the assessment result is often poor universal for a given material, crack and transient, caution is recommended in the safety assessment, especially for the IP. The SIF reduces under the thermal or pressure load if the map cracking (MC) effect is considered. Therefore, the assumption in the ASME and RCCM codes that the cladding should be taken into account in

  16. Relative value of pressures and volumes in assessing fluid responsiveness after valvular and coronary artery surgery.

    Science.gov (United States)

    Breukers, Rose-Marieke B G E; Trof, Ronald J; de Wilde, Rob B P; van den Berg, Paul C M; Twisk, Jos W R; Jansen, Jos R C; Groeneveld, Johan

    2009-01-01

    Cardiac function may differ after valvular (VS) and coronary artery (CAS) surgery and this may affect assessment of fluid responsiveness. The aim of the study was to compare VS and CAS in the value of cardiac filling pressures and volumes herein. There were eight consecutive patients after VS and eight after CAS, with femoral and pulmonary artery catheters in place. In each patient, five sequential fluid loading steps of 250 ml of colloid each were done. We measured central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP) and, by transpulmonary thermodilution, cardiac index (CI) and global end-diastolic (GEDVI) and intrathoracic blood volume (ITBVI) indices. Fluid responsiveness was defined by a CI increase >5% or >10% per step. Global ejection fraction was lower and PAOP was higher after VS than CAS. In responding steps after VS (n=9-14) PAOP and volumes increased, while CVP and volumes increased in responding steps (n=12-19) after CAS. Baseline PAOP was lower in responding steps after VS only. Hence, baseline PAOP as well as changes in PAOP and volumes were of predictive value after VS and changes in CVP and volumes after CAS, in receiver operating characteristic curves. After VS, PAOP and volume changes equally correlated to CI changes. After CAS, only changes in CVP and volumes correlated to those in CI. While volumes are equally useful in monitoring fluid responsiveness, the predictive and monitoring value of PAOP is greater after VS than after CAS. In contrast, the CVP is of similar value as volume measurements in monitoring fluid responsiveness after CAS. The different value of pressures rather than of volumes between surgery types is likely caused by systolic left ventricular dysfunction in VS. The study suggests an effect of systolic cardiac function on optimal parameters of fluid responsiveness and superiority of the pulmonary artery catheter over transpulmonary dilution, for haemodynamic monitoring of VS patients.

  17. ASSESSING TAXPAYER BEHAVIOR IN UTILIZING E-FILLING TAX SYSTEM WITH THE PERSPECTIVE OF TECHNOLOGY ACCEPTANCE MODEL AND THE THEORY OF PLANNED BEHAVIOR

    OpenAIRE

    Maharani H.; Subroto B.; Ghofar A.

    2017-01-01

    This study aims to assess the factors which influence taxpayer behavior in utilizing e-filling tax system. This study combines Technology Acceptance Model and the Theory of Planned Behavior. The data was collected through a survey method. It took 100 respondents of the personal taxpayers of the Pratama Gresik Utara tax office's employee in utilizing the e-filing to submit their tax return. In order to assess the data, the researchers used Partial Least Square statistical method. The finding s...

  18. Become the PPUPET Master: Mastering Pressure Ulcer Risk Assessment With the Pediatric Pressure Ulcer Prediction and Evaluation Tool (PPUPET).

    Science.gov (United States)

    Sterken, David J; Mooney, JoAnn; Ropele, Diana; Kett, Alysha; Vander Laan, Karen J

    2015-01-01

    Hospital acquired pressure ulcers (HAPU) are serious, debilitating, and preventable complications in all inpatient populations. Despite evidence of the development of pressure ulcers in the pediatric population, minimal research has been done. Based on observations gathered during quarterly HAPU audits, bedside nursing staff recognized trends in pressure ulcer locations that were not captured using current pressure ulcer risk assessment tools. Together, bedside nurses and nursing leadership created and conducted multiple research studies to investigate the validity and reliability of the Pediatric Pressure Ulcer Prediction and Evaluation Tool (PPUPET).

  19. Radiographic Assessment of the Technical Quality and Periapical Health of Root-Filled Teeth Performed by General Practitioners in a Turkish Subpopulation

    Directory of Open Access Journals (Sweden)

    E. Tarim Ertas

    2013-01-01

    Full Text Available Aim. The aim of this study was to evaluate by means of radiographs the technical quality of root fillings performed by dental practitioners. Methods and Material. Standardized periapical radiographs were made on 484 patients who received endodontic treatment in private practice. A total of 831 endodontically treated teeth with 1448 roots were evaluated for technical quality of the root canal filling and the periapical status of the teeth. Also, the apical status of each root-filled tooth was assessed according to the length, density, and taper of root fillings, and the presence of apical transportation, broken root instruments, and overfilled sealer or gutta-percha material was recorded for each root canal. Results. Of the endodontically treated teeth 26.6% had healthy periapical tissues, while technically good endodontic treatment constituted 12.8%. Based on the treatment success, there was no significant difference between the tooth groups. Statistical analysis of the data did not demonstrate statistically significant differences between the various parameters that were evaluated (. Conclusions. Technical quality of root fillings in a population who received treatment in private practice was poor and was consistent with a low prevalence of apical health. The probable reasons for this failure are multifactorial and may be improved if the operators improve their skills with continuing postgraduate education programs.

  20. Aging assessment of PWR (Pressurized Water Reactor) Auxiliary Feedwater Systems

    Energy Technology Data Exchange (ETDEWEB)

    Casada, D.A.

    1988-01-01

    In support of the Nuclear Regulatory Commission's Nuclear Plant Aging Research (NPAR) Program, Oak Ridge National Laboratory is conducting a review of Pressurized Water Reactor Auxiliary Feedwater Systems. Two of the objectives of the NPAR Program are to identify failure modes and causes and identify methods to detect and track degradation. In Phase I of the Auxiliary Feedwater System study, a detailed review of system design and operating and surveillance practices at a reference plant is being conducted to determine failure modes and to provide an indication of the ability of current monitoring methods to detect system degradation. The extent to which current practices are contributing to aging and service wear related degradation is also being assessed. This paper provides a description of the study approach, examples of results, and some interim observations and conclusions. 1 fig., 1 tab.

  1. The value of pressure ulcer risk assessment and interface pressure measurements in patients: A nursing perspective

    NARCIS (Netherlands)

    J.T.M. Weststrate

    2005-01-01

    textabstractPressure sores in an intensive care unit 35 and related variables: a descriptive study Prevalence of pressure ulcers, risk factors 47 and the use of pressure-relieving mattresses in ICU patients The clinical relevance of the Waterlow 61 Pressure Sore Risk Scale in the ICU The r

  2. Clinical comparison between HeartMate VE auto-mode and HeartMate XVE auto-mode with Opti-Fill and the effect of stroke volume on blood chamber and inflow valve peak pressures.

    Science.gov (United States)

    Rodermans, Ben F M; Lahpor, Jaap R; van Schelven, Leonard J; Nieuwenhuis, Esther; Sukkel, Eveline Y; van Schouwen-van Kranen, Else

    2007-01-01

    We determined the difference between HeartMate (HM) VE auto mode, average filling 76 mL, and HM XVE Opti-Fill, average filling 79 mL, regarding blood chamber and inflow valve peak pressure pulses (BCPP and IVPP). The relation between stroke volume (SV) and peak pressures was investigated by using a circulatory mock loop. At high SVs, 79 to 83 mL, BCPP and IVPP never exceeded 400 mm Hg. For lower SVs, down to 50 mL, the peak pressures increased to 788 mm Hg for BCPP and 416 mm Hg for IVPP. Distribution of SV was measured in 2 VE and 6 XVE patients during rest and activities of daily living (ADL). For clinical comparison, percentages of SV >78 mL were determined. At rest, 2190 (VE) and 5772 (XVE) pump beats were registered and 4511 (VE) and 8713 (XVE) during ADL. Percentages of "SV >78 mL" at rest, respectively, were 42.5 +/- 3.5 and 78.2 +/- 4.7 (p 78 mL and makes an important contribution to reducing the incidence of high peak pressures in the clinical setting.

  3. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  4. [An assessment scale for the prevention of pressure sores in children].

    Science.gov (United States)

    Chauvet, Corinne; Poirier, Marie-Renée; Sourisseau, Petronela Rachieru; Béduneau, Denis; Soulard, Anthony; Delacroix, Delphine

    2015-04-01

    Pressure sores in children are rare. However, when they do occur they can have significant consequences. Professionals in paediatric units realised the importance of assessing the risk of pressure sores and developed a pressure sore assessment scale specific to children. This project, carried out through a hospital-training school partnership, emphasises the importance of clinical reasoning in nursing practices.

  5. Assessment of imputation methods using varying ecological information to fill the gaps in a tree functional trait database

    Science.gov (United States)

    Poyatos, Rafael; Sus, Oliver; Vilà-Cabrera, Albert; Vayreda, Jordi; Badiella, Llorenç; Mencuccini, Maurizio; Martínez-Vilalta, Jordi

    2016-04-01

    Plant functional traits are increasingly being used in ecosystem ecology thanks to the growing availability of large ecological databases. However, these databases usually contain a large fraction of missing data because measuring plant functional traits systematically is labour-intensive and because most databases are compilations of datasets with different sampling designs. As a result, within a given database, there is an inevitable variability in the number of traits available for each data entry and/or the species coverage in a given geographical area. The presence of missing data may severely bias trait-based analyses, such as the quantification of trait covariation or trait-environment relationships and may hamper efforts towards trait-based modelling of ecosystem biogeochemical cycles. Several data imputation (i.e. gap-filling) methods have been recently tested on compiled functional trait databases, but the performance of imputation methods applied to a functional trait database with a regular spatial sampling has not been thoroughly studied. Here, we assess the effects of data imputation on five tree functional traits (leaf biomass to sapwood area ratio, foliar nitrogen, maximum height, specific leaf area and wood density) in the Ecological and Forest Inventory of Catalonia, an extensive spatial database (covering 31900 km2). We tested the performance of species mean imputation, single imputation by the k-nearest neighbors algorithm (kNN) and a multiple imputation method, Multivariate Imputation with Chained Equations (MICE) at different levels of missing data (10%, 30%, 50%, and 80%). We also assessed the changes in imputation performance when additional predictors (species identity, climate, forest structure, spatial structure) were added in kNN and MICE imputations. We evaluated the imputed datasets using a battery of indexes describing departure from the complete dataset in trait distribution, in the mean prediction error, in the correlation matrix

  6. Pilot study: Assessing repeatability of the EcoWalk platform resistive pressure sensors to measure plantar pressure during barefoot standing

    Science.gov (United States)

    Zequera, Martha; Perdomo, Oscar; Wilches, Carlos; Vizcaya, Pedro

    2013-06-01

    Plantar pressure provides useful information to assess the feet's condition. These systems have emerged as popular tools in clinical environment. These systems present errors and no compensation information is presented by the manufacturer, leading to uncertainty in the measurements. Ten healthy subjects, 5 females and 5 males, were recruited. Lateral load distribution, antero-posterior load distribution, average pressure, contact area, and force were recorded. The aims of this study were to assess repeatability of the EcoWalk system and identify the range of pressure values observed in the normal foot. The coefficient of repeatability was less than 4% for all parameters considered.

  7. Evaluation of skin perfusion pressure to assess refractory foot ulcers.

    Science.gov (United States)

    Kawai, M; Mihara, S; Takahagi, S; Iwamoto, K; Hiragun, T; Hide, M

    2017-05-02

    The number of patients with foot gangrene caused by critical ischaemia and severe infection is increasing significantly in developed countries. The measurement of perilesional skin blood flow by skin perfusion pressure (SPP) is useful to select the appropriate treatment of gangrenous lesions, in that it is not affected by calcifications of blood vessels. However, the prognosis of a foot ulcer may also be affected by the level of blood sugar and infections. This study aimed to validate the use of SPP in cases of foot gangrene and ulcers in patients with and without diabetes mellitus (DM) and infection. Clinical symptoms, ankle-brachial pressure index (ABPI) and SPP were assessed to evaluate the condition of each foot ulcer. Every foot ulcer was treated as independent, even if a participant had multiple ulcers. All ulcers for which we measured SPP were subject to the analysis. All ulcers were purely ischaemic in nature and were exclusively located on the foot or toes. Data were collected from 117 foot ulcers on 91 toes and feet from 65 patients. Almost all SPP values in healed cases were > 27 mmHg. There were three patients whose ulcers failed to heal by conservative treatments were complicated with severe infection. However, no effect of DM on the relationship between SPP values and prognosis was observed. Logistic regression analysis of all ulcers except for the 5 cases complicated with infection revealed that those with 30 mmHg or lower SPP values are likely to heal by conservative treatment with 23% or lower probability, whereas any ulcer with more than 50 mmHg SPP value and without severe infection may heal without the need for further operations with 80% or higher probability. The combination of SPP and careful evaluation of infection may be a good parameter to decide the appropriate treatment for ischaemic skin ulcers, regardless of the complication of DM.

  8. Non-Invasive Method for the Rapid Assessment of Central Venous Pressure: Description and Validation by a Single Examiner

    Directory of Open Access Journals (Sweden)

    Zidulka, Arnold

    2008-11-01

    Full Text Available Objectives: This study describes a means of assessing the external jugular venous pressure (JVP as an indicator of normal or elevated central venous pressure (CVP.Methods: Intensive care unit patients having CVP monitoring were examined. With patients in bed, the external jugular vein (EJV was occluded at the base of the neck and observed to distend. The occlusion was then removed and the vein observed for collapse. Complete collapse was hypothesized to indicate a non-elevated CVP (≤8cm of water. In those patients whose EJV collapsed incompletely, the vein was then occluded with the finger near the angle of the jaw. With the occlusion maintained, the vein was milked downwards with the other hand to cause its emptying and was then observed for filling from below. Filling from below was hypothesized to indicate an elevated CVP (>8cm of water.Results: In 12 of the 40 patients examined, the EJV could not be assessed (EJV not seen at all: 5, and difficult to visualize: 7. For the remaining 28 patients, 11 had a CVP > 8 cm, while 17 had a CVP of < 8. EJV assessment was 100% accurate (95% Confidence Interval 88-100 in predicting whether or not a patient’s CVP was greater or less than 8 cm of water.Conclusion: EJV assessment, when visible, is accurate to clinically assess a patient’s CVP in the hands of the author. Further studies are needed to see if they are reproducible by other observer.[WestJEM. 2008;9:201-205.

  9. Pressure Sensors and Filtering Techniques for Stone Stability Assessment

    NARCIS (Netherlands)

    Hofland, B.

    2001-01-01

    This report is structured as follows: In chapter 2 the importance of wall pressures with respect to the present research is described. The literature on wall pressures that was used, and some general features of wall pressure fluctuations are subsequently described in chapter 3. Chapter 4 deals with

  10. Fracture assessment of the Oskarshamn 1 reactor pressure vessel under cold over-pressurization

    Energy Technology Data Exchange (ETDEWEB)

    Sattari-Far, I. [DNV Technical Consulting AB, Stockholm (Sweden)

    2001-03-01

    The major motivation of this study was to develop a methodology for fracture assessment of surface defects in the 01 reactor pressure vessel under cold loading scenarios, particularly the cold over-pressurization event. According to a previous study, the FENIX project, the cold over-pressurization of the O1 reactor is a limiting loading case, as the ductile/brittle transition temperature (RT{sub NDT}) of certain welds in the O1 beltline region may be over 100 deg C at the-end-of-life condition. The FENIX project gave values of the acceptable and critical crack depth to be equal to the thickness of the cladding layer (about 6 mm) under this load case using the ASME K{sub Ic} reference curve methodology. This study is aimed to develop a methodology to give a more precise fracture assessment of the O1 reactor under cold loading scenarios. Some of the main objectives of this study have been as below: To prepare a material which can simulate the mechanical properties and RT{sub NDT} of the O1 reactor at the end-of-life conditions. To conduct a fracture mechanics test program to cover the essential influencing factors, such as crack geometry (shallow and deep cracks) and loading condition (uniaxial and biaxial) on the cleavage fracture toughness. To perform fracture mechanics analyses to identify a suitable methodology for assessment of the experimental results. To study the responses of engineering fracture assessment methods to the experimental results from the clad specimens. To propose a fracture assessment procedure for determination of the acceptable and critical flaw sizes in the 01 reactor under the cold loading events. A test program consisted of experiments on standard SEN(B) specimens and clad beams, containing surface cracks was conducted during the course of this project. A total of nine clad beams and clad cruciform specimens were tested under uniaxial and biaxial loading. The test material is reactor steel of type A 508 Grade B, which is specially heat

  11. Research on Automotive Air Conditioning Refrigerant Filling Based on Manifold Pressure Gauge%基于歧管压力计的汽车空调制冷剂加注研究

    Institute of Scientific and Technical Information of China (English)

    朱亮亮; 陆健

    2016-01-01

    Automotive air conditioning refrigerant filling, is one of the key projects of automobile maintenance. Through the refrigerant properties and manifold pressure gauge principle of work introduction, refrigerant is filled in automotive air conditioning by manifold pressure gauge, and combines with the pressure detection function, refrigerant state to judge the refrigerant filling quantity; Furthermore qualitative analyzes the six kinds of common leak detection methods. In order to improve the utilization rate of automotive air conditioning, increase the comfort of occupants.%汽车空调系统制冷剂的加注,是汽车保养和维护的关键项目之一。通过制冷剂性能和歧管压力计工作原理的介绍,利用歧管压力计进行制冷剂的加注,并结合其压力检测功能、制冷剂状态等判断制冷剂加注量;并对常用的六种检漏方法进行了定性分析。以此提高汽车空调的利用率,增加驾乘人员的舒适性。

  12. Assessment of continuous intracranial pressure recordings in childhood craniosynostosis.

    Science.gov (United States)

    Eide, Per Kristian; Helseth, Eirik; Due-Tønnessen, Bernt; Lundar, Tryggve

    2002-12-01

    In this study, we explored two strategies of assessing continuous intracranial pressure (ICP) recordings in children with craniosynostosis, namely either by computation of the mean ICP or by computation of the accurate numbers of ICP elevations of different durations. The ICP recordings of 121 consecutive patients with a tentative diagnosis of craniosynostosis who underwent continuous ICP monitoring were examined. The relationship between mean ICP and numbers of ICP elevations was defined. The distribution of numbers of ICP elevations between patients either undergoing surgery or conservative treatment was also compared, since the choice of treatment was heavily dependent on the results of ICP monitoring. At the time of ICP monitoring, calculation of mean ICP was the main parameter for assessment of ICP curves. After a median observation period of 16 months, the ICP curves were reexamined by means of the software Sensometrics Pressure Analyser, which presents the ICP curve as a matrix of numbers of ICP elevations of different levels (20-40 mm Hg) and durations (0.5- 20 min). Since the recording period differed between the cases, the numbers were standardized to a given recording time of 10 h, to allow for comparisons between patients. Cases with a borderline mean ICP during sleep (mean ICP 10-15 mm Hg) constituted 40.5% of the 121 patients. In this group, a rather weak relationship between mean ICP and the number of ICP elevations above 20 mm Hg was found, as well as a relatively high number of ICP elevations above 20 mm Hg of various durations. As compared to the patients undergoing surgery, a rather high number of ICP elevations above 20 mm Hg of various durations was found in patients undergoing conservative treatment. The study confirmed our hypothesis that in children with craniosynostosis, calculation of mean ICP does not describe the ICP curve in a reliable way. Decision-making should also include the computation of the distribution of numbers of ICP

  13. Assessing different mechanisms of toxicity in mountaintop removal/valley fill coal mining-affected watershed samples using Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Elena A Turner

    Full Text Available Mountaintop removal-valley fill coal mining has been associated with a variety of impacts on ecosystem and human health, in particular reductions in the biodiversity of receiving streams. However, effluents emerging from valley fills contain a complex mixture of chemicals including metals, metalloids, and salts, and it is not clear which of these are the most important drivers of toxicity. We found that streamwater and sediment samples collected from mine-impacted streams of the Upper Mud River in West Virginia inhibited the growth of the nematode Caenorhabditis elegans. Next, we took advantage of genetic and transgenic tools available in this model organism to test the hypotheses that the toxicity could be attributed to metals, selenium, oxidative stress, or osmotic stress. Our results indicate that in general, the toxicity of streamwater to C. elegans was attributable to osmotic stress, while the toxicity of sediments resulted mostly from metals or metalloids.

  14. An Assessment of the Compressive Strength of Glass Reinforced Plastic Waste Filled Concrete for Potential Applications in Construction

    Directory of Open Access Journals (Sweden)

    Asokan Pappu

    2010-03-01

    Full Text Available

    Efforts were made to recycle Glass reinforced plastic (GRP waste powder in concrete products and assess its compressive strength to comply with British Standards for use in construction applications. More than 90 GRP waste-filled concrete specimens were

  15. NDT tools for life assessment of high temperature pressure components

    Energy Technology Data Exchange (ETDEWEB)

    Delle Site, C.; De Petris, C.; Mennuti, C. [ISPESL, Rome (Italy)

    2006-07-01

    Creep damage of pressure equipment involves a great variety of high temperature components ranging from superheaters, reheaters, furnaces, reactors, etc. Consequence of failures of these components are of high economic and safety concern. Moreover, the probability of failure of high temperature components is now increasing due to frequent cyclic of power plants imposed by a deregulated market and the search for increasing temperatures in ultrasupercritical plants. In this scenario, a complete NDT campaign is necessary both during the design stage and during the in-service stage. The choice of the specific NDT technique for each component type is of great importance. In this work an overview of the existing NDT techniques for creep designed and operated components are presented. Together with metallographic replica, which is still considered the fundamental tool for creep damage assessment in the majority of materials, other NDT techniques which are able to detect creep cavity or cracks are presented and compared: ultrasonic techniques (tofd and phased-arrays), acoustic emission, holographic interferometry. In the second part of this paper the ability of some NDT tools to support residual life assessments are discussed. Among the most interesting tools are oxide scale ultrasonic measurement, micro-hardness testing, small-punch testing and on-stream deformation measurement. This tools are not strictly devoted to detecting creep defects (such as microcavities or microcracks) rather they give useful information related to creep damage, such as component deformation, material degradation and maximum service temperature. Moreover, a global procedure developed by ISPESL for inspection planning and interpretation of results of NDT examination according to a risk-based approach is presented. Eventually the new features of EN 13445-5 ''Creep Amendments'' concerning inspection and testing on creep designed components are briefly illustrated. (orig.)

  16. CNG 加气站初步设计及安全风险评价%Preliminary Design and Safety Risk Assessment of a CNG Filling Station

    Institute of Scientific and Technical Information of China (English)

    唐倩

    2015-01-01

    CNG(压缩天然气)作为当今汽车能源的重要组成部分,凭借其污染小、经济性好、成本低等优势得到迅速推广,CNG 汽车市场占有率越来越大,CNG 加气站的需求量也日益增加。根据《汽车加油加气站设计与施工规范》,对某 CNG 加气站进行初步设计,并结合国内外 CNG 加气站安全风险评价技术,采取科学、系统、完善的方针,对该 CNG 加气站进行安全风险评价。%CNG (compressed natural gas) as an important part of today's automotive energy, has many advantages, such as low pollution, good economy, low cost and so on, so it has gained rapid promotion, and CNG vehicle market share is growing, the demand of CNG filling station is increasing. In this paper, based on the " Specification for design and construction of automobile gasoline and gas filling station" ,preliminary design of a CNG filling station was carried out, the CNG gas station security risk was assessed by safety risk assessment techniques.

  17. A combination of thermal methods to assess coronary pressure and flow dynamics with a pressure-sensing guide wire.

    Science.gov (United States)

    van der Horst, Arjen; Van't Veer, Marcel; van der Sligte, Robin A M; Rutten, Marcel C M; Pijls, Nico H J; van de Vosse, Frans N

    2013-03-01

    Measurement of coronary pressure and absolute flow dynamics have shown great potential in discerning different types of coronary circulatory disease. In the present study, the feasibility of assessing pressure and flow dynamics with a combination of two thermal methods, developed in combination with a pressure-sensor-tipped guide wire, was evaluated in an in vitro coronary model. A continuous infusion thermodilution method was employed to determine the average flow, whereas a thermal anemometric method was utilized to assess the pressure and flow dynamics, simultaneously. In the latter method, the electrical power supplied to an element, kept at constant temperature above ambient temperature, was used as a measure for the shear rate. It was found that, using a single calibration function, the method was able to assess coronary pressure and flow dynamics for different flow amplitudes, heart rates, and different pressure wires. However, due to the fact that the thermal anemometric method cannot detect local shear rate reversal, the method was unable to reliably measure flow dynamics close to zero. Nevertheless, the combined methodology was able to reliably assess diastolic hemodynamics. The diastolic peak flow and average diastolic resistance could be determined with a small relative error of (8 ± 7)% and (7 ± 5)%, respectively.

  18. Blood Pressure and Global Risk Assessment in a Swedish Population

    OpenAIRE

    Jenny Eckner; Larsson, Charlotte A.; Lennart Råstam; Ulf Lindblad

    2012-01-01

    This study investigated the association between SCORE and the 2007 ESH-ESC blood pressure categories and explored achievements of blood pressure goals considering global risk. In 2001–2005, a random sample of inhabitants aged 30–74 years in southwestern Sweden was invited to a survey of cardiovascular risk factors. The study enrolled 2816 participants (participation rate 76%). Blood pressure was categorized according to the 2007 ESH-ESC guidelines. Global risk of 10-year CVD death was estimat...

  19. Home readings of blood pressure in assessment of hypertensive subjects

    DEFF Research Database (Denmark)

    Nielsen, P.E.; Myschetzky, P; Andersen, A R

    1986-01-01

    Out-patient clinic blood pressure (OPC-BP) was compared to home blood pressure (Home-BP) measured three times daily during a two week period in 122 consecutively referred hypertensive subjects. A semi-automatic device (TM-101) including a microphone for detection of Korotkoff-sounds, self......-deflation of cuff pressure and digital display of blood pressure was used. Mean difference between OPC-BP and Home-BP was systolic +13 mm Hg (range -21 - +100 mg Hg) and diastolic +5 mm Hg (range -27 - +36 mm Hg). Although a significant correlation could be demonstrated between Home-BP and OPC-BP, the inter...

  20. Pressure ulcers and risk assessment in severe burns.

    Science.gov (United States)

    Lewis, Giavonni M; Pham, Tam N; Robinson, Ellen; Otto, Andrew; Honari, Shari; Heimbach, David M; Klein, Matthew B; Gibran, Nicole S

    2012-01-01

    Risk and incidence of pressure ulcers (PUs) in the burn population remain poorly understood. The purpose of this study was to determine the timing and incidence of PUs at our regional burn center and to identify early risk factors for PU development in burn patients. A retrospective review of 40 charts was performed from among the 1489 patients admitted to our regional burn center between January 2008 and December 2009. Twenty patients acquired PUs during their admission and were identified on the basis of International Classification of Diseases, ninth revision, designation, hospital stay >7 days, and thermal injury (excluding toxic epidermal necrolysis and purpura fulminans). The remaining 20 patients were matched controls based on ±5 years in age and ±8% TBSA. Patient, injury, and outcome characteristics were compared among patient groups using χ for categorical variables and Mann-Whitney for continuous variables. The incidence of PU was 1.3% of all admissions. PU most commonly occurred at the sacrum/coccyx (eight), lower extremity (seven), and occiput (six). A majority of PU presented at stage 2 (33%), stage 3 (26%), and unstageable (30%). Thirteen were splint or device related and reportable. Ninety percent of patients with PUs presented with a Braden score of 16 or less (P = .03), although 60% of controls also had admission Braden scores less than 16. On an average, PUs were acquired within 17 days of admission. Data suggest burn patients are particularly at risk of developing PU based on admission Braden scores. However, low Braden scores do not necessarily correlate with eventual development of PU. Therefore, early and aggressive PU prevention and risk assessment tools must be used to diagnose PUs at an early and reversible stage.

  1. Modeling of mould cavity filling process with cast iron in Lost Foam method Part 3. Mathematical model – pressure inside the gas gap

    Directory of Open Access Journals (Sweden)

    T. Pacyniak

    2008-08-01

    Full Text Available In this work mathematical model describing changes of pressure inside the gas gap was shown during manufacturing gray cast iron castings with use of lost foam process. Authors analyzed the results of numerical simulation enclosing influence of foamed polystyrene pattern density, permeability and thickness of refractory coating on pressure changes in the gap. Studies have shown, that all these parameters have significant influence on pressure inside the gas gap.

  2. Pressure ulcer risk assessment and prevention system design.

    OpenAIRE

    Mishu, Mahbub Chowdhury

    2015-01-01

    Pressure ulcer (PU, bedsore, ischemia, decubitus ulcer) has become a global healthcare problem. In United Kingdom 412,000 people develop pressure ulcer annually and it costs the National Health Service (NHS) £1.4-£2.1 billion pounds (4% of total NHS budget). Pressure ulcers are a combined result of multiple factors such as prolonged external load applied to the skin, reduced blood flow in tissues, the patient’s physiological parameters (body mass index, age, mobility) and body support surface...

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

    DEFF Research Database (Denmark)

    Bahlmann, Edda; Cramariuc, Dana; Gerdts, Eva

    2010-01-01

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

  4. Using ambulatory blood pressure monitoring to assess blood pressure of firefighters with parental history of hypertension.

    Science.gov (United States)

    de Mattos, Carlos Eduardo; de Mattos, Marco Antonio; Toledo, Daniele Gusmão; de Siqueira Filho, Aristarco Gonçalves

    2006-12-01

    To evaluate the influence of family history of systemic arterial hypertension (FSAH) on the effect of stress from work in Uniformed Firefighters (BMCs) through Ambulatory Blood Pressure Monitoring (ABPM). A prospective case-control study. Sixty-six healthy BMC underwent ABPM during 12 hours of work at the Communication Center (CC). Thirty-four had hypertensive parents (group 1) and thirty-two had normotensive parents (group 2). Group I differed from group 2 in that it showed higher mean systolic (134.1 +/- 9.9 mmHg X 120.8 +/- 9.9 mmHg p pressure, in addition to greater systolic (31.4 +/- 25.6 % X 9.4 +/- 9.4 % p = 0.0001) and diastolic (28.3 +/- 26.6 % X 6.1 +/- 8.9 % p = 0.0001) loads. The prevalence of systemic arterial hypertension (SAH) in group 1 at the workplace was 32.3%. Monitored away from the job, these subjects showed normal blood pressure (functionally hypertensive). Group 2 revealed normal blood pressure (BP) at work. Higher blood pressure in BMC with hypertensive parents is explained independently by the SAH. Subjects who developed SAH during their work at the CC may be considered functionally hypertensive, whereas those with normotensive parents and who underwent psychological stress are free of blood pressure changes.

  5. Assessment of pressure field calculations from particle image velocimetry measurements

    Science.gov (United States)

    Charonko, John J.; King, Cameron V.; Smith, Barton L.; Vlachos, Pavlos P.

    2010-10-01

    This paper explores the challenges associated with the determination of in-field pressure from DPIV (digital particle image velocimetry)-measured planar velocity fields for time-dependent incompressible flows. Several methods that have been previously explored in the literature are compared, including direct integration of the pressure gradients and solution of different forms of the pressure Poisson equations. Their dependence on grid resolution, sampling rate, velocity measurement error levels and off-axis recording was quantified using artificial data of two ideal sample flow fields—a decaying vortex flow and pulsatile flow between two parallel plates, and real DPIV and pressure data from oscillating flow through a diffuser. The need for special attention to mitigate the velocity error propagation in the pressure estimation is also addressed using a physics-preserving approach based on proper orthogonal decomposition (POD). The results demonstrate that there is no unique or optimum method for estimating the pressure field and the resulting error will depend highly on the type of the flow. However, the virtual boundary, omni-directional pressure integration scheme first proposed by Liu and Katz (2006 Exp. Fluids 41 227-40) performed consistently well in both synthetic and experimental flows. Estimated errors can vary from less than 1% to over 100% with respect to the expected value, though in contrast to more traditional smoothing algorithms, the newly proposed POD-based filtering approach can reduce errors for a given set of conditions by an order of magnitude or more. This analysis offers valuable insight that allows optimizing the choice of methods and parameters based on the flow under consideration.

  6. Pressure-tension test for assessing fatigue in concrete

    Science.gov (United States)

    Soleimani, Sayed M.; Boyd, Andrew J.; Komar, Andrew J. K.

    2017-04-01

    In a pressure-tension test, a cylindrical concrete specimen is inserted into a cylindrical steel jacket, with a rubber ``O'' ring seal at each end to prevent gas leakage. Gas pressure is then applied to the curved surface of the concrete cylinder, leaving the ends free. As the gas pressure is increased, the specimen eventually fractures across a single plane transverse to the axis of the cylinder. The gas pressure at fracture may then be considered as the tensile strength of the concrete. In this study, the pressure-tension test is used to study fatigue in concrete. A total of 22 standard concrete cylinders (100 mm × 200 mm) were tested. Both dry and wet specimens have been studied. Low-cycle loading, which involves the application of a few load cycles at high stress levels - such as a concrete structure under earthquake load - has been used in this study. It was found that the concrete specimens in a low-cycle loading fail after only a few cycles of loading and interestingly at a stress level lower than the maximum value applied in the cyclic loading. In addition, non-destructive testing (NDT) was performed to determine the progressive damage due to tensile load in concrete cylinders using Ultrasonic Pulse Velocity (UPV). It was found that UPV can be used to evaluate the damage in concrete even after the application of a very low-level of tensile stress - as low as 10% of its tensile strength.

  7. Assessment of tunnel’s face support pressure

    Science.gov (United States)

    Hrubesova, Eva; Duris, Lukas

    2017-09-01

    The evaluation of support pressure ensuring tunnel’s face stability during excavation using tunnel boring machines is one of the fundamental problems in tunnelling. This paper presents various approaches to this problem. The analytical models, based either on the principle of limit equilibrium or the limiting analysis (low boundary or upper boundary limiting methods), requires considerable simplification (circular tunnel, homogeneous rock mass etc.). But, on the other hand they are less time-consuming in comparison with the numerical models based on the finite element method. This paper describes the comparison of results of minimum face pressure obtained on the basis of different calculation methods with respect to the specific geometrical and material characteristics of the problem. Geotechnical software Midas GTS NX (based on finite element method) was used for presented numerical analysis. The paper also provides a comparison of modelling results with the results of the face pressure corresponding to the real excavation of the tunnel.

  8. ASSESSING TAXPAYER BEHAVIOR IN UTILIZING E-FILLING TAX SYSTEM WITH THE PERSPECTIVE OF TECHNOLOGY ACCEPTANCE MODEL AND THE THEORY OF PLANNED BEHAVIOR

    Directory of Open Access Journals (Sweden)

    Maharani H.

    2017-07-01

    Full Text Available This study aims to assess the factors which influence taxpayer behavior in utilizing e-filling tax system. This study combines Technology Acceptance Model and the Theory of Planned Behavior. The data was collected through a survey method. It took 100 respondents of the personal taxpayers of the Pratama Gresik Utara tax office's employee in utilizing the e-filing to submit their tax return. In order to assess the data, the researchers used Partial Least Square statistical method. The finding shows that the intention construct has a positive influence over the e-filling utilization behavior. Behavioral control has a positive influence over the behavior through the e-filing utilization intention. Easy of use, purpose, attitude, subjective norm, and behavioral control have a positive influence over the e-filing utilization intention. Credibility has a negative influence over the e-filing utilization intention. This study involved the Application Service Provider, Directorate General of Taxes, and KPP Pratama which have to more pay attention the behavior, intention, easy of use, purpose, attitude, subjective norm, and behavioral control of the taxpayer.

  9. Rheological assessment of nanofluids at high pressure high temperature

    Science.gov (United States)

    Kanjirakat, Anoop; Sadr, Reza

    2013-11-01

    High pressure high temperature (HPHT) fluids are commonly encountered in industry, for example in cooling and/or lubrications applications. Nanofluids, engineered suspensions of nano-sized particles dispersed in a base fluid, have shown prospective as industrial cooling fluids due to their enhanced rheological and heat transfer properties. Nanofluids can be potentially utilized in oil industry for drilling fluids and for high pressure water jet cooling/lubrication in machining. In present work rheological characteristics of oil based nanofluids are investigated at HPHT condition. Nanofluids used in this study are prepared by dispersing commercially available SiO2 nanoparticles (~20 nm) in a mineral oil. The basefluid and nanofluids with two concentrations, namely 1%, and 2%, by volume, are considered in this investigation. The rheological characteristics of base fluid and the nanofluids are measured using an industrial HPHT viscometer. Viscosity values of the nanofluids are measured at pressures of 100 kPa to 42 MPa and temperatures ranging from 25°C to 140°C. The viscosity values of both nanofluids as well as basefluid are observed to have increased with the increase in pressure. Funded by Qatar National Research Fund (NPRP 08-574-2-239).

  10. Performance assessment of low pressure nuclear thermal propulsion

    Science.gov (United States)

    Gerrish, Harrold P., Jr.; Doughty, Glen E.

    1993-01-01

    An increase in Isp for nuclear thermal propulsion systems is desirable for reducing the propellant requirements and cost of future applications, such as the Mars Transfer Vehicle. Several previous design studies have suggested that the Isp could be increased substantially with hydrogen dissociation/recombination. Hydrogen molecules (H2), at high temperatures and low pressures, will dissociate to monatomic hydrogen (H). The reverse process (i.e., formation of H2 from H) is exothermic. The exothermic energy in a nozzle increases the kinetic energy and therefore, increases the Isp. The low pressure nuclear thermal propulsion system (LPNTP) system is expected to maximize the hydrogen dissociation/recombination and Isp by operating at high chamber temperatures and low chamber pressures. The process involves hydrogen flow through a high temperature, low pressure fission reactor, and out a nozzle. The high temperature (approximately 3000 K) of the hydrogen in the reactor is limited by the temperature limits of the reactor material. The minimum chamber pressure is about 1 atm because lower pressures decrease the engines thrust to weight ratio below acceptable limits. This study assumes that hydrogen leaves the reactor and enters the nozzle at the 3000 K equilibrium dissociation level. Hydrogen dissociation in the reactor does not affect LPNTP performance like dissociation in traditional chemical propulsion systems, because energy from the reactor resupplies energy lost due to hydrogen dissociation. Recombination takes place in the nozzle due primarily to a drop in temperature as the Mach number increases. However, as the Mach number increases beyond the nozzle throat, the static pressure and density of the flow decreases and minimizes the recombination. The ideal LPNTP Isp at 3000 K and 10 psia is 1160 seconds due to the added energy from fast recombination rates. The actual Isp depends on the finite kinetic reaction rates which affect the amount of monatomic hydrogen

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

    DEFF Research Database (Denmark)

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

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

  12. Cardiovascular simulator improvement: pressure versus volume loop assessment.

    Science.gov (United States)

    Fonseca, Jeison; Andrade, Aron; Nicolosi, Denys E C; Biscegli, José F; Leme, Juliana; Legendre, Daniel; Bock, Eduardo; Lucchi, Julio Cesar

    2011-05-01

    This article presents improvement on a physical cardiovascular simulator (PCS) system. Intraventricular pressure versus intraventricular volume (PxV) loop was obtained to evaluate performance of a pulsatile chamber mimicking the human left ventricle. PxV loop shows heart contractility and is normally used to evaluate heart performance. In many heart diseases, the stroke volume decreases because of low heart contractility. This pathological situation must be simulated by the PCS in order to evaluate the assistance provided by a ventricular assist device (VAD). The PCS system is automatically controlled by a computer and is an auxiliary tool for VAD control strategies development. This PCS system is according to a Windkessel model where lumped parameters are used for cardiovascular system analysis. Peripheral resistance, arteries compliance, and fluid inertance are simulated. The simulator has an actuator with a roller screw and brushless direct current motor, and the stroke volume is regulated by the actuator displacement. Internal pressure and volume measurements are monitored to obtain the PxV loop. Left chamber internal pressure is directly obtained by pressure transducer; however, internal volume has been obtained indirectly by using a linear variable differential transformer, which senses the diaphragm displacement. Correlations between the internal volume and diaphragm position are made. LabVIEW integrates these signals and shows the pressure versus internal volume loop. The results that have been obtained from the PCS system show PxV loops at different ventricle elastances, making possible the simulation of pathological situations. A preliminary test with a pulsatile VAD attached to PCS system was made.

  13. About Dental Amalgam Fillings

    Science.gov (United States)

    ... and Medical Procedures Dental Devices Dental Amalgam About Dental Amalgam Fillings Share Tweet Linkedin Pin it More ... should I have my fillings removed? What is dental amalgam? Dental amalgam is a dental filling material ...

  14. Development and validity of a new model for assessing pressure redistribution properties of support surfaces.

    Science.gov (United States)

    Matsuo, Junko; Sugama, Junko; Sanada, Hiromi; Okuwa, Mayumi; Nakatani, Toshio; Konya, Chizuko; Sakamoto, Jirou

    2011-05-01

    Pressure ulcers are a common problem, especially in older patients. In Japan, most institutionalized older people are malnourished and show extreme bony prominence (EBP). EBP is a significant factor in the development of pressure ulcers due to increased interface pressure concentrated at the skin surface over the EBP. The use of support surfaces is recommended for the prophylaxis of pressure ulcers. However, the present equivocal criteria for evaluating the pressure redistribution of support surfaces are inadequate. Since pressure redistribution is influenced by physique and posture, evaluations using human subjects are limited. For this reason, models that can substitute for humans are necessary. We developed a new EBP model based on the anthropometric measurements, including pelvic inclination, of 100 bedridden elderly people. A comparison between the pressure distribution charts of our model and bedridden elderly subjects demonstrated that maximum contact pressure values, buttock contact pressure values, and bone prominence rates corresponded closely. This indicates that the model provides a good approximation of the features of elderly people with EBP. We subsequently examined the validity of the model through quantitative assessment of pressure redistribution functions consisting of immersion, envelopment, and contact area change. The model was able to detect differences in the hardness of urethane foam, differences in the internal pressure of an air mattress, and sequential changes during the pressure switching mode. These results demonstrate the validity of our new buttock model in evaluating pressure redistribution for a variety of surfaces.

  15. Analysis of the Pressure Rise in a Partially Filled Liquid Tank in Microgravity with Low Wall Heat Flux and Simultaneous Boiling and Condensation

    Science.gov (United States)

    Hasan, Mohammad M.; Balasubramaniam, R.

    2012-01-01

    Experiments performed with Freon 113 in the space shuttle have shown that in a pro- cess of very slow heating, high liquid superheats can be sustained for a long period in microgravity. In a closed system explosive vaporization of superheated liquid resulted in pressure spikes of varying magnitudes. In this paper, we analyze the pressure rise in a partially lled closed tank in which a large vapor bubble (i.e., ullage) is initially present, and the liquid is subjected to a low wall heat ux. The liquid layer adjacent to the wall becomes superheated until the temperature for nucleation of the bubbles (or the incipience of boiling) is achieved. In the absence of the gravity-induced convection large quantities of superheated liquid can accumulate over time near the heated surface. Once the incipience temperature is attained, explosive boiling occurs and the vapor bubbles that are produced on the heater surface tend to quickly raise the tank pressure. The liquid-vapor saturation temperature increases as well. These two e ects tend to induce condensation of the large ullage bubble that is initially present, and tends to mitigate the tank pressure rise. As a result, the tank pressure is predicted to rise sharply, attain a maximum, and subsequently decay slowly. The predicted pressure rise is compared with experimental results obtained in the microgravity environments of the space shuttle for Freon 113. The analysis is appli- cable, in general to heating of liquid in closed containers in microgravity and to cryogenic fuel tanks, in particular where small heat leaks into the tank are unavoidable.

  16. Assessing Predictive Validity of Pressure Ulcer Risk Scales- A Systematic Review and Meta-Analysis

    OpenAIRE

    2016-01-01

    Background: The purpose of this study was to present a scientific reason for pressure ulcer risk scales: Cubbin& Jackson modified Braden, Norton, and Waterlow, as a nursing diagnosis tool by utilizing predictive validity of pressure sores. Methods: Articles published between 1966 and 2013 from periodicals indexed in the Ovid Medline, Embase, CINAHL, KoreaMed, NDSL, and other databases were selected using the key word “pressure ulcer”. QUADAS-II was applied for assessment for internal validity...

  17. Computerized cuff pressure algometry: A new method to assess deep-tissue hypersensitivity in fibromyalgia.

    Science.gov (United States)

    Jespersen, Anders; Dreyer, Lene; Kendall, Sally; Graven-Nielsen, Thomas; Arendt-Nielsen, Lars; Bliddal, Henning; Danneskiold-Samsoe, Bente

    2007-09-01

    The aim of this study was to evaluate the use of computerized cuff pressure algometry (CPA) in fibromyalgia (FM) and to correlate deep-tissue sensitivity assessed by CPA with other disease markers of FM. Forty-eight women with FM and 16 healthy age-matched women were included. A computer-controlled, pneumatic tourniquet cuff was placed over the gastrocnemius muscle. The cuff was inflated, and the subject rated the pain intensity continuously on an electronic Visual Analogue Scale (VAS). The subject stopped the inflation at the pressure-pain tolerance and the corresponding VAS-score was determined (pressure-pain limit). The pressure at which VAS firstly exceeded 0 was defined as the pressure-pain threshold. Other disease markers (FM only): Isokinetic knee muscle strength, tenderpoint-count, myalgic score, Beck Depression Inventory, and Fibromyalgia Impact Questionnaire. Student's T-test was used to compare pressure-pain threshold and pressure-pain tolerance and the Mann-Whitney test to compare pressure-pain limit. Pearson's correlation was used to detect linear relationships. Pressure-pain threshold and pressure-pain tolerance assessed by CPA were significantly lower in FM compared to healthy controls. There was no difference in pressure-pain limit. CPA-parameters were significantly correlated to isokinetic muscle strength where more hypersensitivity resulted in lower strength. Pressure-pain threshold and pressure-pain tolerance assessed by CPA were significantly lower in patients with FM indicating muscle hyperalgesia. CPA was associated with knee muscle strength but not with measures thought to be influenced by psychological distress and mood.

  18. Developing a pressure ulcer risk factor minimum data set and risk assessment framework

    NARCIS (Netherlands)

    Coleman, S.; Nelson, E.A.; Keen, J.; Wilson, L.; McGinnis, E.; Dealey, C.; Stubbs, N.; Muir, D.; Farrin, A.; Dowding, D.; Schols, J.M.; Cuddigan, J.; Berlowitz, D.; Jude, E.; Vowden, P.; Bader, D.L.; Gefen, A.; Oomens, C.W.; Schoonhoven, L.; Nixon, J.

    2014-01-01

    AIM: To agree a draft pressure ulcer risk factor Minimum Data Set to underpin the development of a new evidenced-based Risk Assessment Framework. BACKGROUND: A recent systematic review identified the need for a pressure ulcer risk factor Minimum Data Set and development and validation of an evidence

  19. Cricoid pressure: assessment of performance and effect of training in emergency department staff.

    Science.gov (United States)

    Quigley, Paul; Jeffrey, Penelope

    2007-06-01

    (i) To evaluate the theoretical knowledge and practical skills of ED staff regarding the technique of cricoid pressure; (ii) to assess the efficacy of two methods of cricoid pressure training. Theoretical knowledge of participants was assessed by a pretraining questionnaire, and practical ability was assessed using a Flinders Meditech cricoid pressure trainer. Participants then received a brief period of theoretical instruction, and were allocated to two training groups. Group A received further training with the pressure trainer. Group B was provided with reading material. Practical ability was assessed again immediately and then 4-6 weeks later. Seventy subjects were recruited. A total of 53% could identify the position of the cricoid cartilage, and 16% could identify the pressure required. The percentage achieving a correct position at baseline, immediately after training and after 4-6 weeks was 47%, 97% and 70% respectively in group A, compared with 61%, 86% and 74% respectively in group B, a non-significant difference between groups. The percentage achieving correct pressure at baseline, immediately after training and 4-6 weeks later was 38%, 88% and 67% respectively in group A, compared with 30%, 33% and 51% respectively in group B. The between-group difference was significant only immediately following training (P < 0.0001). Theoretical knowledge and technique regarding cricoid pressure was poor among our ED staff. Both methods of training appeared to improve performance. The biofeedback group was more likely to apply correct pressure immediately after training. The effects of training diminished rapidly with time.

  20. Cardiovascular pressure measurement in safety assessment studies: technology requirements and potential errors.

    Science.gov (United States)

    Sarazan, R Dustan

    2014-01-01

    In the early days of in vivo nonclinical pressure measurement, most laboratories were required to have considerable technical/engineering expertise to configure and maintain pressure transducers, amplifiers, tape recorders, chart recorders, etc. Graduate students and postdoctoral fellows typically had some training in the requirements and limitations of the technology they used and were closely engaged in the collection and evaluation of data from their own experiments. More recently, pressure sensing telemetry and data acquisition/analysis systems are provided by vendors as turnkey systems, often resulting in a situation where users are less familiar with the technicalities of their operation. Also, investigators are now more likely to be absent and rely on technical staff for the collection of raw in vivo pressure data from their experiments than in the past. Depending on the goals of an experiment, an investigator may require the measurement of a variety of different pressure parameters, over varying periods of time. A basic understanding of the requirements and limitations that can affect the accuracy and precision of these parameters is important to ensure that the results and conclusions from an experiment are reliable. Factors to consider include the possibility of hydrostatic pressure effects from blood inside the vasculature of the animal, depending on the location of the sensor, as well as from fluid inside a fluid-filled catheter system; long-term stability (lack of drift) of a sensor over time, which can affect the interpretation of absolute pressure changes over a prolonged experiment; frequency response of the sensor and associated electronics; and the phase shift that occurs depending on location of the sensor in the vasculature or because of a fluid-filled catheter system. Each of these factors is discussed, and the particular requirements of frequency response as applied to the measurement of cardiac left ventricular pressure are emphasized. When

  1. 吹填土真空预压工程中孔压计改进埋设方法的研究%Improvement of Laying Pore Water Pressure Gauge for Vacuum Preloading of Dredger Fill

    Institute of Scientific and Technical Information of China (English)

    徐永辉; 汤明礼; 俞炯奇; 王文双

    2014-01-01

    This paper introduced two laying methods of pore water pressure gauge for vacuum preloading of dredger fill , i . e . traditional method of laying by drilling and an improved one of laying by spile machine , and compared monitoring data of the two methods . Results show that the gauge laid by spile machine will produce excess pore water pressure and the dissipation time of this pressure at deep measuring points is longer than that of pressure gauge laid by drilling . For pore water pressure gauge at shallow levels , using spile machine is convenient and cost -effective;while for pore water pressure gauge below 15m , traditional method of laying by drilling should be adopted .%介绍了吹填土真空预压工程中孔隙水压力计(以下简称“孔压计”)的传统钻孔埋设方法和改进埋设方法-插板机埋设,对使用改进埋设方法的监测数据进行了分析,并与钻孔埋设方法的监测数据进行比较。分析表明,采用插板机埋设的孔压计中产生明显超静孔隙水压力,且深部测点超静孔隙水压力消散所需时间较钻孔埋设的长;对于浅层深度的孔压计可采用插板机埋设,节省施工成本,方便快捷,而超过15 m深度的孔压计埋设则需采用常规钻孔。

  2. FAILURE ASSESSMENT OF DEFECTIVE GATHERINGTUBE UNDER HIGH PRESSURE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A numerical model on stress assessment of a defective elliptic gathering tube used in the heat recovery boiler of a pyrolyzer is built up. The effect of local defects on the carrying capacity of the tube is analyzed by using the MSC/NASTRAN finite element code, and the critical size of defects is obtained. Then, two numerical models of damaged tube with local and integral reinforcements, respectively, are also calculated. Stress classification and assessments are provided by applying the ASME and JB4732-1995 standard. Some guidance and suggestions about the tube reinforcements and the prediction of the remaining life of the structure for engineering practice are discussed.

  3. Predictive Validity of Pressure Ulcer Risk Assessment Tools for Elderly: A Meta-Analysis.

    Science.gov (United States)

    Park, Seong-Hi; Lee, Young-Shin; Kwon, Young-Mi

    2016-04-01

    Preventing pressure ulcers is one of the most challenging goals existing for today's health care provider. Currently used tools which assess risk of pressure ulcer development rarely evaluate the accuracy of predictability, especially in older adults. The current study aimed at providing a systemic review and meta-analysis of 29 studies using three pressure ulcer risk assessment tools: Braden, Norton, and Waterlow Scales. Overall predictive validities of pressure ulcer risks in the pooled sensitivity and specificity indicated a similar range with a moderate accuracy level in all three scales, while heterogeneity showed more than 80% variability among studies. The studies applying the Braden Scale used five different cut-off points representing the primary cause of heterogeneity. Results indicate that commonly used screening tools for pressure ulcer risk have limitations regarding validity and accuracy for use with older adults due to heterogeneity among studies.

  4. Integrated probabilistic assessment for DHC initiation, growth and leak-before-break of PHWR pressure tubes

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Young-Jin [Power Engineering Research Institute, KEPCO Engineering and Construction, 188 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-870 (Korea, Republic of); Chang, Yoon-Suk, E-mail: yschang@khu.ac.kr [Department of Nuclear Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of)

    2014-08-15

    Highlights: • We develop an integrated approach for probabilistic assessment of PHWR pressure tube. • We examine probabilities of DHC initiation, growth, penetration and LBB failure. • The proposed approach is helpful to calculate rupture probabilities in reactor flaws even in the case of very low rupture probability. - Abstract: A few hundred zirconium alloy pressure tubes in a pressurized heavy water reactor (PHWR) serve as the nuclear fuel channel, as well as the reactor coolant pressure boundary. The pressure tubes are inspected periodically and a fitness-for-service assessment (FFSA) must be conducted if any flaw is detected in the inspection. A Canadian standard provides FFSA procedures of PHWR pressure tubes, which include probabilistic assessment for flaws considering delayed hydride cracking (DHC) and leak-before-break (LBB). In the present study, an integrated approach with detailed stepwise calculation procedures and integration methodology for probabilistic assessment of pressure tube was developed. In the first step of this approach, a probability of the DHC initiation, growth and penetration for single initial flaw is calculated. In the next step, a probability of LBB failure, which means tube rupture, for single through-wall crack (TWC) is calculated. Finally, a rupture probability for all initial flaws in a reactor can be calculated using the penetration probability for single flaw and the LBB failure probability for single TWC, as well as the predicted total number of initial flaw in the reactor.

  5. Modelling of Filling, Microstructure Formation, Local Mechanical Properties and Stress – Strain Development in High-Pressure Die Cast Aluminium Castings

    DEFF Research Database (Denmark)

    Kotas, Petr; Hattel, Jesper Henri; Thorborg, Jesper

    2009-01-01

    inherently affects the component’s properties depending on design, metallurgy and casting technique. The wall thickness influences the coarseness of the microstructure and the material will have properties depending on the local metallurgical and thermal histories. This is independent on the material, i.......e. whether the casting is based on cast iron- or aluminium-alloys. The distribution of local properties in a casting might vary substantially which makes it complex to optimize the casting with good accuracy. Often, mechanical simulations of the load situation are based on the assumption that the cast...... product has constant material properties throughout the entire casting. Thus, if the microstructure is determined or predicted at a given point, it gives the possibility to calculate the local material behavior more realistically. In the present work, a test case of a complex high-pressure die cast part...

  6. Development of a simple maintenance method for condition assessment of oil filled XLPE terminations. Diagnostic testing, oil, humidity and asset management

    Energy Technology Data Exchange (ETDEWEB)

    Liland, Knut Brede

    2011-02-15

    Development of a simple method for condition assessment of oil filled XLPE terminations An on-site/off-line prototype method for measuring water content at different positions inside oil filled high voltage cable terminations has been developed. The method consists of: 1) Measurement rod with relative humidity and temperature sensors in addition to a conductivity sensor for measuring free water in the bottom of the termination, 2) Characterisation database for three oils for converting relative humidity and temperature to absolute humidity, 3) Wireless unit for data transfer from the measurement rod to a computer and 4) Procedure for doing the measurements. The method proved to be a powerful and very simple tool in estimating the humidity and level of the oil in the termination and also detecting free water. The method was compared with more traditional and time consuming methods taking oil samples from the terminations. The agreement between the laboratory and the on-site measurements were very good. In only 10-15 minutes it was possible to diagnose the condition of the termination with respect to humidity. During the project more fundamental work studying from a provoked leakage of water into a transparent cable termination were performed by master student Geir Birkenes (NTNU) supervised by Frank Mauseth (NTNU) and Sverre Hvidsten (SINTEF Energy Research). The behavior of water droplets during leakage was visually studied and the development of the relative humidity from installed relative humidity sensors in the zero field regions below the cone was monitored on-line. Partial discharge activity (pd) was also monitored and proved that such installations are very robust. PD is not a very good method for detecting water leakage and water content in such devices due to the intermittent and in general very low discharge levels. (Author)

  7. A prospective, longitudinal study to assess use of continuous and reactive low-pressure mattresses to reduce pressure ulcer incidence in a pediatric intensive care unit

    OpenAIRE

    García Molina, Pablo; Balaguer López, Evelin; Torra i Bou, Joan Enric; Álvarez Ordiales, Adán; Quesada Ramos, Cristina; Verdú Soriano, José

    2012-01-01

    Pressure between bony prominences and sleep surfaces, as well as pressure from the use of medical devices, put children admitted to pediatric intensive care units (PICUs) at risk of developing pressure ulcers (PUs). To assess the effect of two pediatric-specific, continuous and reactive low-pressure mattresses on the incidence of PUs, an observational, descriptive, prospective, longitudinal (2009–2011) study was conducted among PICU patients. The two pediatric mattresses — one for children we...

  8. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  9. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  10. Getting a prescription filled

    Science.gov (United States)

    ... are located inside of a grocery or large "chain" store. It is best to fill all prescriptions ... be used for long-term medicines and medical supplies. The website should have clear directions for filling ...

  11. Assessment of pressure-pain thresholds and central sensitization of pain in lateral epicondylalgia

    DEFF Research Database (Denmark)

    Jespersen, Anders; Amris, Kirstine; Graven-Nielsen, Thomas

    2013-01-01

    pressure stimulation at intensity relative to the individual pain threshold, the pain intensity was continuously recorded using an electronic visual analogue scale (VAS), and from this the degree of temporal summation was estimated. For LE, a Doppler ultrasound examination of the elbow was made to identify......OBJECTIVE.: To assess pain sensitivity and spreading hyperalgesia in lateral epicondylalgia (LE). SUBJECTS.: Twenty-two women with LE, and 38 controls were included. OUTCOME MEASURES.: Computerized cuff pressure algometry was used for assessment of pressure-pain threshold and tolerance....... The stimulus was applied using a single (stimulation-area: 241 cm(2) ) or double-chambered (stimulation-area: 482 cm(2) ) tourniquet on the arm and leg. Spatial summation was expressed as the ratio between pressure-pain thresholds to single and double cuff-chamber stimulation. During 10-minute constant...

  12. Longitudinal assessment of high blood pressure in children with nonalcoholic fatty liver disease.

    Science.gov (United States)

    Schwimmer, Jeffrey B; Zepeda, Anne; Newton, Kimberly P; Xanthakos, Stavra A; Behling, Cynthia; Hallinan, Erin K; Donithan, Michele; Tonascia, James

    2014-01-01

    Nonalcoholic fatty liver disease (NAFLD) affects 9.6% of children and may put these children at elevated risk of high blood pressure and subsequent cardiovascular morbidity and mortality. Therefore, we sought to determine the prevalence of and risk factors for high blood pressure in children with NAFLD. Cohort study performed by the NIDDK NASH Clinical Research Network. There were 484 children with NAFLD ages 2 to 17 at enrollment; 382 children were assessed both at enrollment and 48 weeks afterwards. The main outcomes were high blood pressure at baseline and persistent high blood pressure at both baseline and 48 weeks. Prevalence of high blood pressure at baseline was 35.8% and prevalence of persistent high blood pressure was 21.4%. Children with high blood pressure were significantly more likely to have worse steatosis than children without high blood pressure (mild 19.8% vs. 34.2%, moderate 35.0% vs. 30.7%, severe 45.2% vs. 35.1%; P = 0.003). Higher body mass index, low-density lipoprotein, and uric acid were independent risk factors for high blood pressure (Odds Ratios: 1.10 per kg/m2, 1.09 per 10 mg/dL, 1.25 per mg/dL, respectively). Compared to boys, girls with NAFLD were significantly more likely to have persistent high blood pressure (28.4% vs.18.9%; P = 0.05). In conclusion, NAFLD is a common clinical problem that places children at substantial risk for high blood pressure, which may often go undiagnosed. Thus blood pressure evaluation, control, and monitoring should be an integral component of the clinical management of children with NAFLD.

  13. Longitudinal assessment of high blood pressure in children with nonalcoholic fatty liver disease.

    Directory of Open Access Journals (Sweden)

    Jeffrey B Schwimmer

    Full Text Available Nonalcoholic fatty liver disease (NAFLD affects 9.6% of children and may put these children at elevated risk of high blood pressure and subsequent cardiovascular morbidity and mortality. Therefore, we sought to determine the prevalence of and risk factors for high blood pressure in children with NAFLD.Cohort study performed by the NIDDK NASH Clinical Research Network. There were 484 children with NAFLD ages 2 to 17 at enrollment; 382 children were assessed both at enrollment and 48 weeks afterwards. The main outcomes were high blood pressure at baseline and persistent high blood pressure at both baseline and 48 weeks.Prevalence of high blood pressure at baseline was 35.8% and prevalence of persistent high blood pressure was 21.4%. Children with high blood pressure were significantly more likely to have worse steatosis than children without high blood pressure (mild 19.8% vs. 34.2%, moderate 35.0% vs. 30.7%, severe 45.2% vs. 35.1%; P = 0.003. Higher body mass index, low-density lipoprotein, and uric acid were independent risk factors for high blood pressure (Odds Ratios: 1.10 per kg/m2, 1.09 per 10 mg/dL, 1.25 per mg/dL, respectively. Compared to boys, girls with NAFLD were significantly more likely to have persistent high blood pressure (28.4% vs.18.9%; P = 0.05.In conclusion, NAFLD is a common clinical problem that places children at substantial risk for high blood pressure, which may often go undiagnosed. Thus blood pressure evaluation, control, and monitoring should be an integral component of the clinical management of children with NAFLD.

  14. A simplified approach for assessing the leak-before-break for the flawed pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, P. [Ramagundam Super Thermal Power Station, NTPC Ltd, Jyothinagar 505215 (India); Amirthagadeswaran, K.S. [Faculty of Mechanical Engineering, Government College of Technology, Coimbatore 641013 (India); Christopher, T. [Faculty of Mechanical Engineering, Government College of Engineering, Tirunelveli 627007 (India); Nageswara Rao, B., E-mail: bnrao52@rediffmail.com [Faculty of Mechanical Engineering, School of Mechanical and Civil Sciences, K L University, Green Fields, Vaddeswaram, Guntur 522502 (India)

    2016-06-15

    Surface cracks or embedded cracks in pressure vessels under service may grow and form stable through-thickness cracks causing leak prior to failure. If this leak-before-break phenomenon takes place, then there is a possibility of preventing the vessel failure. This paper presents a simplified approach for assessing the leak-before-break or failure of the flawed pressure vessels. This approach is validated through comparison of existing test data.

  15. Assessment of Computer Simulation Software and Process Data for High Pressure Die Casting of Magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL; Hatfield, Edward C [ORNL; Dinwiddie, Ralph Barton [ORNL; Kuwana, Kazunori [University of Kentucky; Viti, Valerio [University of Kentucky, Lexington; Hassan, Mohamed I [University of Kentucky, Lexington; Saito, Kozo [University of Kentucky

    2007-09-01

    Computer software for the numerical simulation of solidification and mold filling is an effective design tool for cast structural automotive magnesium components. A review of commercial software capabilities and their validation procedures was conducted. Aside form the software assessment, the program addressed five main areas: lubricant degradation, lubricant application, gate atomization, and heat transfer at metal mold interfaces. A test stand for lubricant application was designed. A sensor was used for the direct measurement of heat fluxes during lubricant application and casting solidification in graphite molds. Spray experiments were conducted using pure deionized water and commercial die lubricants. The results show that the sensor can be used with confidence for measuring heat fluxes under conditions specific to the die lube application. The data on heat flux was presented in forms suitable for use in HPDC simulation software. Severe jet breakup and atomization phenomena are likely to occur due to high gate velocities in HPDC. As a result of gate atomization, droplet flow affects the mold filling pattern, air entrapment, skin formation, and ensuing defects. Warm water analogue dies were designed for obtaining experimental data on mold filling phenomena. Data on break-up jet length, break-up pattern, velocities, and droplet size distribution were obtained experimentally and was used to develop correlations for jet break-up phenomena specific to die casting gate configurations.

  16. A TWO-PHASE FLOW MODEL FOR SIMULATING AIR ENTRAPMENT DURING MOLD FILLING OF HIGH PRESSURE DIE CASTING PROCESS%应用两相流模型模拟压铸充型过程的卷气现象

    Institute of Scientific and Technical Information of China (English)

    李帅君; 熊守美; Mei Li; John Allison

    2009-01-01

    通过对压铸充型过程中卷气缺陷形成机理的分析,认为型腔中空气的流动以及与金属液之间的相互作用是形成卷气现象的主要原因.为了考虑型腔中空气的流动,采用了一种不可压缩两相流数学模型来模拟压铸充型过程的卷气现象.通过计算流体力学中的两个基准算例,较为全面地验证了该模型的准确性和可靠性.在此基础上,设计了专门针对压铸充型过程的高速水模拟实验,通过对可视化实验结果与两相流模拟结果的比较,证实二者吻合较好,说明了该模型能够较好地模拟液体的充填行为和卷入其中的气泡.%The most common defect found in high pressure die casting (HPDC) process is the gas porosity which significantly affects the mechanical properties of the final components. The generation of gas porosity is known mainly due to the air entrapment in the liquid metal during the mold filling stage. Knowing the trapped-air location and amount could allow for a more accurate and objective analysis of casting quality. In the past few decades, extensive efforts have been made to develop simulation codes of casting flow. Most of these codes solve the velocity, pressure and fluid fraction only in the liquid phase with the assumption that the effect of air in the die cavity is negligible. As a matter of fact, the air in the die cavity has significant influence on the filling pattern of the molten metal and the gas porosity distribution of the die casts. Recently, following the development of computational fluid dynamics (CFD), two-phase flow models have drawn continuous attention in the numerical simulation of casting processes, but there are still few models and further studies are needed. In this study, the mechanism of the formation of air entrapment defects in the HPDC process was discussed and it turned out that the air flow in the die cavity as well as the interaction between air and liquid metal resulted in the final air

  17. An interrater reliability study of the assessment of pressure ulcer risk using the Braden scale and the classification of pressure ulcers in a home care setting.

    Science.gov (United States)

    Kottner, Jan; Halfens, Ruud; Dassen, Theo

    2009-10-01

    Measurement error can seriously affect the validity of pressure ulcer risk assessment and of pressure ulcer classification. Determination of interrater reliability and agreement of pressure ulcer risk and pressure ulcers using the Braden scale and the EPUAP system. Duplicate assessments by trained nurses during two nationwide pressure ulcer prevalence surveys in the years 2007 and 2008 in The Netherlands in the home care setting. Home care clients which participated in 2007 (n=352) and 2008 (n=339) in the pressure ulcer prevalence surveys. The Braden scale was used to assess pressure ulcer risk. Skin examination was conducted to detect pressure related tissue damages and to classify them according to the EPUAP. In 2007 and 2008, Intraclass Correlation Coefficients for Braden scale sum scores were 0.90 (95% CI: 0.88-0.92) and 0.88 (95% CI: 0.85-0.91) respectively, and corresponding Standard Errors of Measurement were 1.00 and 0.98. 95% limits of agreement were -2.8 to 2.8 and -2.7 to 2.7 respectively. The items "moisture", "sensory perception" and "nutrition" contained largest amounts of measurement error. Proportions of agreement for the classification of pressure ulcers were 96% and interrater reliability was 0.81 and 0.79. Most disagreements were observed for the classification of grade 1 pressure ulcers. The standardized study procedure applied in the annual nationwide pressure ulcer prevalence surveys leads to reliable and reproducible results regarding pressure ulcer risk and pressure ulcer prevalence in the home care setting. Researchers and practitioners should be careful when drawing inferences from single pressure ulcer risk factors included in the Braden scale. Descriptions of the items "moisture", "sensory perception" and "nutrition" should be made more clearly and unambiguous.

  18. Seepage characteristics of collapse column fillings

    Institute of Scientific and Technical Information of China (English)

    Zhang Boyang; Bai Haibo; Zhang Kai

    2016-01-01

    With concealment and hysteresis, water-inrush from Karst collapse column has become an important security hazard of lower group coal mining in North China. Based on the MTS815.02 seepage test system, we analyzed the impact of consolidation pressure, initial moisture content and confining pressure on the permeability of fillings in order to study the seepage characteristics of collapse column fillings. The results show that:(1) The permeability of collapse column fillings is of the order of 10?16–10?15 magni-tude and decreases with an increase in consolidation pressure and decrease in initial moisture content. (2) The essence of filling seepage law change is the change in porosity, and a power function relationship exists between the permeability ratio and porosity ratio. (3) With increasing confining pressure, the per-meability of fillings decreases. However, under low confining pressure (1.2–4 MPa), the change of confin-ing pressure has no obvious influence on the permeability.

  19. Intraluminal pressure patterns in the human colon assessed by high-resolution manometry.

    Science.gov (United States)

    Chen, Ji-Hong; Yu, Yuanjie; Yang, Zixian; Yu, Wen-Zhen; Chen, Wu Lan; Yu, Hui; Kim, Marie Jeong-Min; Huang, Min; Tan, Shiyun; Luo, Hesheng; Chen, Jianfeng; Chen, Jiande D Z; Huizinga, Jan D

    2017-02-20

    Assessment of colonic motor dysfunction is rarely done because of inadequate methodology and lack of knowledge about normal motor patterns. Here we report on elucidation of intraluminal pressure patterns using High Resolution Colonic Manometry during a baseline period and in response to a meal, in 15 patients with constipation, chronically dependent on laxatives, 5 healthy volunteers and 9 patients with minor, transient, IBS-like symptoms but no sign of constipation. Simultaneous pressure waves (SPWs) were the most prominent propulsive motor pattern, associated with gas expulsion and anal sphincter relaxation, inferred to be associated with fast propagating contractions. Isolated pressure transients occurred in most sensors, ranging in amplitude from 5-230 mmHg. Rhythmic haustral boundary pressure transients occurred at sensors about 4-5 cm apart. Synchronized haustral pressure waves, covering 3-5 cm of the colon occurred to create a characteristic intrahaustral cyclic motor pattern at 3-6 cycles/min, propagating in mixed direction. This activity abruptly alternated with erratic patterns resembling the segmentation motor pattern of the small intestine. High amplitude propagating pressure waves (HAPWs) were too rare to contribute to function assessment in most subjects. Most patients, dependent on laxatives for defecation, were able to generate normal motor patterns in response to a meal.

  20. Pressure ulcers: effectiveness of risk-assessment tools. A randomised controlled trial (the ULCER trial).

    Science.gov (United States)

    Webster, Joan; Coleman, Kerrie; Mudge, Alison; Marquart, Louise; Gardner, Glenn; Stankiewicz, Monica; Kirby, Julie; Vellacott, Catherine; Horton-Breshears, Margaret; McClymont, Alice

    2011-04-01

    To evaluate the effectiveness of two pressure-ulcer screening tools against clinical judgement in preventing pressure ulcers. A single blind randomised controlled trial. A large metropolitan tertiary hospital. 1231 patients admitted to internal medicine or oncology wards. Patients were excluded if their hospital stay was expected to be 2 days or less. Participants allocated to either a Waterlow (n=410) or Ramstadius (n=411) screening tool group or to a clinical judgement group (n=410) where no formal risk screening instrument was used. Incidence of hospital acquired pressure ulcers ascertained by regular direct observation. Use of any devices for the prevention of pressure ulcers, documentation of a pressure plan and any dietetic or specialist skin integrity review were recorded. On admission, 71 (5.8%) patients had an existing pressure ulcer. The incidence of hospital-acquired pressure ulcers was similar between groups (clinical judgement 28/410 (6.8%); Waterlow 31/411 (7.5%); Ramstadius 22/410 (5.4%), p=0.44). Significant associations with pressure injury in regression modelling included requiring a dietetic referral, being admitted from a location other than home and age over 65 years. The authors found no evidence to show that two common pressure-ulcer risk-assessment tools are superior to clinical judgement to prevent pressure injury. Resources associated with use of these tools might be better spent on careful daily skin inspection and improving management targetted at specific risks. The trial was registered with the Australian and New Zealand Clinicat Trials Registry (ACTRN 12608000541303).

  1. [Device to assess in-socket pressure distribution for partial foot amputation].

    Science.gov (United States)

    Alvarez-Camacho, Michelín; Urrusti, José Luis; Acero, María Del Carmen; Galván Duque-Gastélum, Carlos; Rodríguez-Reyes, Gerardo; Mendoza-Cruz, Felipe

    2014-07-01

    A device for dynamic acquisition and distribution analysis of in-socket pressure for patients with partial foot amputation is presented in this work. By using the developed system, we measured and generated pressure distribution graphs, obtained maximal pressure, and calculated pressure-time integral (PTI) of three subjects with partial foot amputation and of a group of Healthy subjects (Hs) (n = 10). Average maximal pressure in the healthy group was 19.4 ± 4.11 PSI, while for the three amputated patients, this was 27.8 ± 1.38, 17.6 ± 1.15, 29.10 ± 3.9 PSI, respectively. Maximal pressure-time integral for healthy subjects was 11.56 ± 2.83 PSI*s, and for study subjects was 19.54 ± 1.9, 12.35 ± 1.48, and 13.17 ± 1.31 PSI*s, respectively. The results of the control group agree with those previously reported in the literature. The pressure distribution pattern showed clear differences between study subjects and those of the control group; these graphs allowed us to identify the pressure in regions-of-interest that could be critical, such as surgical scars. The system presented in this work will aid to assess the effectiveness with which prosthetic systems distribute load, given that the formation of ulcers is highly linked to the pressure exercised at the point of contact; in addition, these results will help to investigate the comfort perception of the prosthesis, a factor directly influenced by the stump's pressure distribution.

  2. Central blood pressure assessment using 24-hour brachial pulse wave analysis

    Directory of Open Access Journals (Sweden)

    Muiesan ML

    2014-10-01

    Full Text Available Maria Lorenza Muiesan, Massimo Salvetti, Fabio Bertacchini, Claudia Agabiti-Rosei, Giulia Maruelli, Efrem Colonetti, Anna Paini Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy Abstract: This review describes the use of central blood pressure (BP measurements during ambulatory monitoring, using noninvasive devices. The principles of measuring central BP by applanation tonometry and by oscillometry are reported, and information on device validation studies is described. The pathophysiological basis for the differences between brachial and aortic pressure is discussed. The currently available methods for central aortic pressure measurement are relatively accurate, and their use has important clinical implications, such as improving diagnostic and prognostic stratification of hypertension and providing a more accurate assessment of the effect of treatment on BP. Keywords: aortic blood pressure measurements, ambulatory monitoring, pulse wave analysis

  3. Assessing endothelial function and providing calibrated UFMD data using a blood pressure cuff

    Energy Technology Data Exchange (ETDEWEB)

    Maltz, Jonathan S.

    2017-08-22

    Methods and apparatus are provided for assessing endothelial function in a mammal. In certain embodiments the methods involve using a cuff to apply pressure to an artery in a subject to determine a plurality of baseline values for a parameter related to endothelial function as a function of applied pressure (P.sub.m); b) applying a stimulus to the subject; and applying external pressure P.sub.m to the artery to determine a plurality of stimulus-effected values for the parameter related to endothelial function as a function of applied pressure (P.sub.m); where the baseline values are determined from measurements made when said mammal is not substantially effected by said stimulus and differences in said baseline values and said stimulus-effected values provide a measure of endothelial function in said mammal.

  4. Assessment of TRACE Code for MIT Pressurizer Tests to Review Industrial Code

    Energy Technology Data Exchange (ETDEWEB)

    Song, Chanyi; Bang, Young Seok; Shin, Andong; Woo, Sweng-Wong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-10-15

    Korea Institute of Nuclear Safety (KINS) has initiated to review the industrial code for safety analysis of nuclear power plant, in which MARS-KS and TRACE codes are being used to support the understanding of specific phenomena and code prediction. For this aspect, the TRACE code was assessed for the MIT pressurizer test. The TRACE code has been developed continuously, and NRC released the TRACE code version 5.0 patch 4 recently. This updated version has some improvement from version 5.0 patch 3. In this paper, TRACE code calculations with version 5.0 patch 3 and patch 4 for 3 cases of MIT pressurizer tests have been performed to assess the applicability of the TRACE code for verification of industrial codes. The MIT pressurizer test is one of the fundamental separate effect tests and frequently simulated to verify safety analysis codes. Predictability of the system code for the behavior of pressurizer in the plant is very important because it has an effect on the progress of accidents such as loss of coolant, control rod withdrawal, and loss of feedwater flow, etc. In the reactor protection system, the high pressurizer pressure trip signal provides an assurance of the integrity of the RCS boundary for AOOs that could lead to an over pressurization of the RCS. Also, the low pressurizer pressure trip signal provides an assistance for the ESF during the system pressure reduction events and a LOCA. According to the results, node effect was significantly reduced at patch 4 compared with patch 3 of TRACE version 5.0. Based on the prediction of Test ST4 and Test A, at least 20 cells are needed to predict pressurizer insurge behavior reasonably. However, the results of patch 4 show that 10 cells are enough to simulate the transient behavior of pressurizer. For outsurge case B, there was no major difference between patch 3 and patch 4 even though it was not shown in this paper. Overall, the results of the TRACE code version 5.0 patch 4 fit well with those of experiments

  5. A micro-computed tomography assessment of the efficacy of rotary and reciprocating techniques for filling material removal in root canal retreatment.

    Science.gov (United States)

    Monguilhott Crozeta, Bruno; Damião de Sousa-Neto, Manoel; Bianchi Leoni, Graziela; Francisco Mazzi-Chaves, Jardel; Terezinha Corrêa Silva-Sousa, Yara; Baratto-Filho, Flares

    2016-11-01

    The aim of this study was to compare the efficacy of rotary and reciprocating techniques for removing filling material from root canals, using micro-computed tomography (micro-CT) imaging. The distal root canals of 42 human mandibular molars were instrumented with hand files up to size 40 according to a step-down technique and obturated with gutta-percha and an epoxy resin-based sealer using Tagger's hybrid technique. Teeth were divided into six groups (n = 7) according to the instruments used for removal of filling material: group PTUR (Protaper Universal Retreatment), group W40 (WaveOne 40.08), group R40 (Reciproc 40.06), group R50 (Reciproc 50.05), group W25/W40 (WaveOne 25.08/40.08), and group R25/R40/R50 (Reciproc 25.08/40.06/50.05). Teeth were scanned with a micro-CT device before and after use of the instruments to calculate the percentage of remaining filling material. Data were compared using one-way ANOVA and Fisher's LSD test at 5 % significance level. The mean percentage of remaining filling material was significantly lower when canals were retreated with the set of instruments R25/R40/R50 and single instruments W40 and R50 compared with the set of instruments W25/W40 (P removed the root fillings completely. PTUR instruments performed equally effective regarding filling removal compared with W40, R40, R50, W25/W40, and R25/R40/R50. For WaveOne, the use of a single instrument (size 40, taper 0.08) was more effective in removing filling material, while for Reciproc showed similar cleaning ability using single instrument or combination of instruments. The results of this in vitro study provide consistent information on filling material removal capacity of mechanized systems during retreatment at the different root canal thirds.

  6. Pain assessment in patellar tendinopathy using pain pressure threshold algometry: : An observational study

    NARCIS (Netherlands)

    Kregel, Jeroen; van Wilgen, Cornelis Paul; Zwerver, Johannes

    2013-01-01

    ObjectiveAssessing pain in patellar tendinopathy (PT) is difficult to perform in a standardized way. With this study, we measured pain in athletes with PT by means of pain pressure threshold (PPT) algometry in a standardized manner. Subsequently, the goal of this study is to determine normative

  7. Identifying and classifying quality-of-life tools for assessing pressure ulcers after spinal cord injury

    Science.gov (United States)

    Hitzig, Sander L.; Balioussis, Christina; Nussbaum, Ethne; McGillivray, Colleen F.; Catharine Craven, B.; Noreau, Luc

    2013-01-01

    Context Although pressure ulcers may negatively influence quality of life (QoL) post-spinal cord injury (SCI), our understanding of how to assess their impact is confounded by conceptual and measurement issues. To ensure that descriptions of pressure ulcer impact are appropriately characterized, measures should be selected according to the domains that they evaluate and the population and pathologies for which they are designed. Objective To conduct a systematic literature review to identify and classify outcome measures used to assess the impact of pressure ulcers on QoL after SCI. Methods Electronic databases (Medline/PubMed, CINAHL, and PsycInfo) were searched for studies published between 1975 and 2011. Identified outcome measures were classified as being either subjective or objective using a QoL model. Results Fourteen studies were identified. The majority of tools identified in these studies did not have psychometric evidence supporting their use in the SCI population with the exception of two objective measures, the Short-Form 36 and the Craig Handicap Assessment and Reporting Technique, and two subjective measures, the Life Situation Questionnaire-Revised and the Ferrans and Powers Quality of Life Index SCI-Version. Conclusion Many QoL outcome tools showed promise in being sensitive to the presence of pressure ulcers, but few of them have been validated for use with SCI. Prospective studies should employ more rigorous methods for collecting data on pressure ulcer severity and location to improve the quality of findings with regard to their impact on QoL. The Cardiff Wound Impact Schedule is a potential tool for assessing impact of pressure ulcers-post SCI. PMID:24090238

  8. Basin-fill Aquifer Modeling with Terrestrial Gravity: Assessing Static Offsets in Bulk Datasets using MATLAB; Case Study of Bridgeport, CA

    Science.gov (United States)

    Mlawsky, E. T.; Louie, J. N.; Pohll, G.; Carlson, C. W.; Blakely, R. J.

    2015-12-01

    Understanding the potential availability of water resources in Eastern California aquifers is of critical importance to making water management policy decisions and determining best-use practices for California, as well as for downstream use in Nevada. Hydrologic well log data can provide valuable information on aquifer capacity, but is often proprietarily inaccessible or economically unfeasible to obtain in sufficient quantity. In the case of basin-fill aquifers, it is possible to make estimates of aquifer geometry and volume using geophysical surveys of gravity, constrained by additional geophysical and geological observations. We use terrestrial gravity data to model depth-to-basement about the Bridgeport, CA basin for application in preserving the Walker Lake biome. In constructing the model, we assess several hundred gravity observations, existing and newly collected. We regard these datasets as "bulk," as the data are compiled from multiple sources. Inconsistencies among datasets can result in "static offsets," or artificial bull's-eye contours, within the gradient. Amending suspect offsets requires the attention of the modeler; picking these offsets by hand can be a time-consuming process when modeling large-scale basin features. We develop a MATLAB script for interpolating the residual Bouguer anomaly about the basin using sparse observation points, and leveling offset points with a user-defined sensitivity. The script is also capable of plotting gravity profiles between any two endpoints within the map extent. The resulting anomaly map provides an efficient means of locating and removing static offsets in the data, while also providing a fast visual representation of a bulk dataset. Additionally, we obtain gridded basin gravity models with an open-source alternative to proprietary modeling tools.

  9. An in-vitro comparative study for assessment of apical sealing ability of Epiphany/AH Plus sealer with Resilon/gutta-percha root canal filling materials

    Science.gov (United States)

    Sultana, Meraj; Musani, Mohammad A.; Ahmed, Iffat M.

    2016-01-01

    Aims and Objectives: Endodontic treatment is directed to eliminate microbial challenges from the root canal system and to create a complete seal. The aim of this study was to assess the apical sealing ability of resin-based Epiphany-Resilon root canal filling system and to compare it with the sealing abilities of different combinations of AH Plus, gutta-percha, Epiphany, and Resilon. Materials and Methods: One hundred extracted human maxillary incisor roots were treated endodontically. The samples were divided into groups A, B, C, and D, with each group containing 25 samples. Group A: Canals obturated with gutta-percha and AH Plus sealer; Group B: Canals obturated with Resilon and Epiphany; Group C: Canals obturated with gutta-percha and Epiphany; Group D: Control group canals obturated with gutta-percha without a sealer. The sealing ability of each of the obturation techniques was tested using the dye penetration method followed by the clearing method using alcohol. Stereo microscope was used to measure the extent of dye penetration. Statistical data analysis was performed using analysis of variance and Tukey tests. Results: Microleakage was found in all the four groups. Apical extent of mean microleakage was maximum for gutta-percha, followed by Gutta-percha + AH-plus and Gutta-percha + Epiphany, and the least with Resilon + Epiphany. Statistically significant difference (P < 0.01) was seen in the apical leakage. Conclusion: All the samples tested showed microleakage. The “Epiphany soft resin endodontic obturation system” showed a superior result compared to other obturation materials. PMID:27583220

  10. Advantage analysis of Karst water-filled coal beds mining under Water Pressure%岩溶充水煤矿床带水压开采优势分析

    Institute of Scientific and Technical Information of China (English)

    卿国屏; 何红生; 唐忆晨; 张江柳

    2014-01-01

    我国南方广泛分布岩溶充水煤矿床,矿山通常采用强排疏干开采,排水成本极高,更严重的是引发了诸多环境地质问题,造成了巨大的经济损失及恶劣的社会影响。湖南煤业集团辰溪矿业有限公司大坪煤矿为岩溶充水煤矿床,该矿在后期生产过程中,充分利用岩溶发育的不均一性,采取了砌筑水闸墙等措施进行井下堵水,使矿井排水量大幅度减少,地下水位得以区域性恢复,避免了岩溶地面塌陷地质灾害,成功实现了带水压开采。本文概述了大坪煤矿的水文地质、工程地质条件,研究了该矿矿床直接充水含水层的岩溶发育规律;从经济效益、环境效益及社会效益等方面分析了带水压开采的优势;对岩溶充水煤矿床科学、安全开采煤炭资源,建设“两型矿山”有一定指导意义。%Adopting strong emission dewatering in the karst water-filled coal bed ,widely distributed in south of China ,often produces high drainage costs and more seriously ,triggering many environmental geological problems , resulting in huge economic losses and adverse social impact . Daping Coal Mine , Chenxi mining Ltd of Hunan Mining Group , a karst water-filled coal bed , taking advantage of karst heterogeneity ,has taken measures such as masonry walls sluice underground water shutoff in the production process ,which makes mine a displacement greatly reduced and the groundwater level to regional recovery , avoiding the collapse of karst ground geological disasters and achieving with hydraulic mining .Based on the brief conditions of hydrogeology and engineering geology ,this paper studies the karst development law of the direct water-filled aquifers .The benefits on the economic ,environmental and social are studied with mining under water pressure .This paper is of certain guiding significance for karst water-filled coal bed scientific ,safe mining of coal resources and the

  11. Assessment of musculoskeletal pain sensitivity and temporal summation by cuff pressure algometry

    DEFF Research Database (Denmark)

    Graven-Nielsen, Thomas; Vaegter, Henrik Bjarke; Finocchietti, Sara

    2015-01-01

    ) conditioned pain modulation (CPM) assessed by cuff algometry. The influences of age and gender were evaluated. On two different days, cuff pain threshold (cPPT), cuff pain tolerance (cPTT), and temporal summation of pain (TSP) by visual analogue scale scores to 10 repeated cuff stimulations at cPTT intensity......, as well as pressure pain threshold (PPT) with handheld pressure algometry were assessed in 136 healthy subjects. In one session cuff pain sensitivity was also assessed before and after the cold-pressor induced CPM. Good to excellent intraclass correlations (ICCs: 0.60 - 0.90) were demonstrated for manual.......05). TSP were increased in women compared with men (PCPM demonstrated as increased cPPT, cPTT and reduced TSP (P

  12. Non-invasive bedside assessment of central venous pressure: scanning into the future.

    Directory of Open Access Journals (Sweden)

    Jacques Rizkallah

    Full Text Available Noninvasive evaluation of central venous pressure (CVP can be achieved by assessing the Jugular Venous Pressure (JVP, Peripheral Venous Collapse (PVC, and ultrasound visualization of the inferior vena cava. The relative accuracy of these techniques compared to one another and their application by trainees of varying experience remains uncertain. We compare the application and utility of the JVP, PVC, and handheld Mini Echo amongst trainees of varying experience including a medical student, internal medicine resident, and cardiology fellow. We also introduce and validate a new physical exam technique to assess central venous pressures, the Anthem sign.Patients presenting for their regularly scheduled echocardiograms at the hospital echo department had clinical evaluations of their CVP using these non-invasive bedside techniques. The examiners were blinded to the echo results, each other's assessments, and patient history; their CVP estimates were compared to the gold standard level 3 echo-cardiographer's estimates at the completion of the study.325 patients combined were examined (mean age 65, s.d. 16 years. When compared to the gold standard of central venous pressure by a level 3 echocardiographer, the JVP was the most sensitive at 86%, improving with clinical experience (p<0.01. The classic PVC technique and Anthem sign had better specificity compared to the JVP. Mini Echo estimates were comparable to physical exam assessments.JVP evaluation is the most sensitive physical examination technique in CVP assessments. The PVC techniques along with the newly described Anthem sign may be of value for the early learner who still has not mastered the art of JVP assessment and in obese patients in whom JVP evaluation is problematic. Mini Echo estimates of CVPs are comparable to physical examination by trained clinicians and require less instruction. The use of Mini Echo in medical training should be further evaluated and encouraged.

  13. Braden Scale risk assessments and pressure ulcer prevention planning: what's the connection?

    Science.gov (United States)

    Magnan, Morris A; Maklebust, Joann

    2009-01-01

    To investigate the relationship between risk assessment scores on Braden subscales and nurses' selection of 10 commonly used best-practice pressure ulcer (PU) preventive interventions. Exploratory secondary data analysis, using a descriptive correlational design. A total of 377 Braden Scale PU risk assessments were made on 102 patients at different levels of risk. Assessments were made by RNs working at 3 different acute care hospitals. RNs making risk assessments also used an intervention checklist to select from 10 commonly used preventive interventions that should be implemented based on patient level of risk on each Braden subscale. The Braden Scale for Predicting Pressure Sore Risk was used to guide risk assessments. The Registered Nurses Intervention Checklist was used to identify PU preventive interventions that should be implemented. Braden subscale ratings influenced nurses' endorsement of preventive interventions in 2 distinct ways. First, endorsement of most (9 out of 10) preventive interventions was influenced by risk information embedded in unique combinations of Braden subscale assessments. Second, there appears to be a predictable pattern of increase in the likelihood of endorsing an intervention as Braden subscale scores decreased and the level of risk increased. Variability in Braden subscale ratings differentially predicts nurses' endorsements of selected PU-prevention interventions. Also, there is a predictable pattern of increase in the likelihood of endorsing a preventive intervention as PU risk levels increase, a pattern that may be related to the timing of risk assessment and PU-prevention planning activities.

  14. Hydro-Coupling Effects on Compression Symmetry in Gas-Filled Hohlraum Experiments at the Omega Laser

    Energy Technology Data Exchange (ETDEWEB)

    Dewalds, E L; Pollaine, S W; Landen, O L; Amendt, P A; Turner, R E; Wallace, R; Campbell, K M; Glenzer, S H

    2003-08-26

    Ignition hohlraum designs use low Z gas fill to slow down the inward progress of high Z ablated plasma from the hohlraum walls preventing large laser spot motion and capsule drive asymmetries. In order to optimize the ignition design, the gas hydro-coupling effect to a fusion capsule asymmetry is presently being assessed in experiments at the Omega laser facility with gas filled hohlraums and foam balls. Our experiments measure the effects of the pressure spike that is generated by direct gas heating by the drive laser beams on the capsule surrogate for various hohlraum gas fill densities (0-2.5 mg/cc). To isolate the effect of the gas-hydro coupling pressure, we have begun by using plastic ''hohlraums'' to reduce the x-ray ablation pressure. The foam ball images measured by x-ray backlighting show increasing pole-hot pressure asymmetry for increasing gas pressure. In addition, the gas hydrodynamics is studied by imaging of a low concentration Xe gas fill dopant. The gas fill self-emission. shows the early pressure spike and its propagation towards the foam ball, as well as the gas stagnation on the holraum axis at later times, both contributing to the capsule asymmetry. These first gas hydro-coupling results are compared to LASNEX simulations.

  15. Water-filled telescopes

    CERN Document Server

    Antonello, E

    2014-01-01

    In this short note we discuss the case of the thought experiments on water-filled telescopes and their realizations during 18th and 19th century. The story of those instruments shows that the scientific progress occurs in a curious way, since there was no stringent reason for the construction of a water-filled telescope.

  16. Interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis.

    NARCIS (Netherlands)

    Smidt, N.; Windt, A. van der; Assendelft, W.J.; Mourits, A.J.; Devillé, W.L.; Winter, F. de; Bouter, L.M.

    2002-01-01

    Objective: To evaluate the interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis in primary care. Design: Two physiotherapists assessed independently, and in randomized order, the severity of

  17. Interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis

    NARCIS (Netherlands)

    Smidt, N; van der Windt, DA; Assendelft, WJ; Mourits, AJ; Deville, WL; de Winter, AF; Bouter, LM

    2002-01-01

    Objective: To evaluate the interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis in primary care. Design: Two physiotherapists assessed independently, and in randomized order, the severity of compl

  18. Interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis.

    NARCIS (Netherlands)

    Smidt, N.; Windt, A. van der; Assendelft, W.J.; Mourits, A.J.; Devillé, W.L.; Winter, F. de; Bouter, L.M.

    2002-01-01

    Objective: To evaluate the interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis in primary care. Design: Two physiotherapists assessed independently, and in randomized order, the severity of compl

  19. Functional assessment of lesion severity without using the pressure wire: coronary imaging and blood flow simulation.

    Science.gov (United States)

    Papafaklis, Michail I; Mavrogiannis, Michail C; Siogkas, Panagiotis K; Lakkas, Lampros S; Katsouras, Christos S; Fotiadis, Dimitrios I; Michalis, Lampros K

    2017-09-19

    Hemodynamic indices derived from measurements with the pressure wire (primarily fractional flow reserve [FFR]) have been established as a reliable tool for assessing coronary stenoses and improving clinical decision making. However, the use of the pressure wire constitutes a hurdle for the universal adoption of physiology-guided patient management. Technological advancements have enabled the large-scale application of blood flow simulation (computational fluid dynamics [CFD]) to medical imaging, thereby enabling the virtual assessment of coronary physiology. Areas covered: This review summarizes the stand-alone non-invasive (coronary computed tomographic imaging) and invasive (coronary angiography) imaging approaches which were initially used for predicting FFR, and focuses on the use of blood flow modeling for functional assessment of coronary lesions in clinical practice. Expert commentary: Validation studies of CFD-derived methodologies for functional assessment have shown that virtual indices correlate well and have good diagnostic accuracy compared to pressure wire-FFR despite inherent limitations of spatial resolution and assumptions regarding boundary conditions in flow modeling. Beyond point-to-point agreement with FFR, further studies are needed to demonstrate the clinical safety/efficacy of these computational tools regarding patient outcomes. Such evidence base could support the incorporation of these methodologies into routine patient management for decision making and reliable risk stratification.

  20. Selenium in ecosystems within the mountaintop coal mining and valley-fill region of southern West Virginia-assessment and ecosystem-scale modeling

    Science.gov (United States)

    Presser, Theresa S.

    2013-01-01

    Coal and associated waste rock are among environmental selenium (Se) sources that have the potential to affect reproduction in fish and aquatic birds. Ecosystems of southern West Virginia that are affected by drainage from mountaintop coal mines and valleys filled with waste rock in the Coal, Gauley, and Lower Guyandotte watersheds were assessed during 2010 and 2011. Sampling data from earlier studies in these watersheds (for example, Upper Mud River Reservoir) and other mining-affected watersheds also are included to assess additional hydrologic settings and food webs for comparison. Basin schematics give a comprehensive view of sampled species and Se concentration data specific to location and date. Food-web diagrams document the progression of Se trophic transfer across suspended particulate material, invertebrates, and fish for each site to serve as the basis for developing an ecosystem-scale model to predict Se exposure within the hydrologic conditions and food webs of southern West Virginia. This approach integrates a site-specific predator’s dietary exposure pathway into modeling to ensure an adequate link to Se toxicity and, thus, to species vulnerability. Site-specific fish abundance and richness data in streams documented various species of chub, shiner, dace, darters, bass, minnow, sunfish, sucker, catfish, and central stoneroller (Campostoma anomalum), mottled sculpin (Cottus bairdii), and least brook lamprey (Lampetra aepyptera). However, Se assessment species for streams, and hence, model species for streams, were limited to creek chub (Semotilus atromaculatus) and central stoneroller. Both of these species of fish are generally considered to have a high tolerance for environmental stress based on traditional comparative fish community assessment, with creek chub being present at all sites. Aquatic insects (mayfly, caddisfly, stonefly, dobsonfly, chironomid) were the main invertebrates sampled in streams. Collection of suspended particulate material

  1. Kinetic assessment of measured mass flow rates and streamwise pressure distributions in microchannel gas flows

    Institute of Scientific and Technical Information of China (English)

    Jing Fan; Chong Xie; Jianzheng Jiang

    2007-01-01

    Measured mass flow rates and streamwise pressure distributions of gas flowing through microchannels were reported by many researchers. Assessment of these data is crucial before they are used in the examination of slip models and numerical schemes, and in the design of microchannel elements in various MEMS devices. On the basis of kinetic solutions of the mass flow rates and pressure distributions in microchannel gas flows, the measured data available are properly normalized and then are compared with each other. The 69 normalized data of measured pressure distributions are in excellent agreement, and 67 of them are within 1 ± 0.05. The normalized data of mass flow-rates ranging between 0.95 and 1 agree well with each other as the inlet Knudsen number Kni > 0.02, but they scat ter between 0.85 and 1.15 as Kni < 0.02 with, to some extent, a very interesting bifurcation trend.

  2. Invasive assessment of doubtful aortic stenosis by measuring simultaneous transaortic gradient with a pressure wire.

    Science.gov (United States)

    Chopard, Romain; Meneveau, Nicolas; Plastaras, Philoktimon; Janin, Sebastien; Seronde, Marie-France; Ecarnot, Fiona; Schiele, Francois

    2013-06-15

    Two-dimensional transthoracic echocardiography (2D-TTE) is the reference technique for evaluating aortic stenosis (AS) but may be unreliable in some cases. We aimed to assess whether the use of a pressure wire to measure simultaneous transaortic gradient and aortic valve area (AVA) could be helpful in patients in whom initial noninvasive evaluations were considered doubtful for AS. Fifty-seven patients (mean age 76 years; 39 men) underwent cardiac catheterization with single arterial access for assessment of AVA with the Gorlin and Gorlin formula. Transaortic pressure was obtained by 2 invasive methods: (1) conventional pullback method (PM) from the left ventricle toward the aorta and (2) simultaneous method (SM) with transaortic pressure simultaneously recorded with a 0.014-inch pressure wire introduced into the left ventricle and with a diagnostic catheter placed in the ascending aorta. Reasons for inaccurate assessment by 2D-TTE were low flow states (88%) and/or atrial fibrillation (79%). Agreement for severe AS defined by AVA <0.6 cm²/m² between SM and 2D-TTE and between SM and PM was fair, with kappa coefficients of 0.38 (95% confidence interval [CI] 0.14-0.75) and 0.36 (95% CI 0.22-0.7) respectively; agreement was poor between 2D-TTE and PM (kappa: 0.23; 95% CI 0.002-0.36). SM led to a reclassification of the severity of AS in 9 patients (15.8%) compared with 2D-TTE and in 11 patients (19.3%) compared with PM. In conclusion, invasive evaluation of doubtful AS by measuring simultaneous transaortic gradient using a pressure wire may provide an attractive method that can lead to a change in therapeutic strategy in a substantial proportion of patients.

  3. A numerical assessment of the load bearing capacity of externally pressurized moderately thick tubes

    Energy Technology Data Exchange (ETDEWEB)

    Corradi, Leone [Politecnico di Milano - Department of Energy, Enrico Fermi Center for Nuclear Studies (CeSNEF), via Ponzio 34/3 - 20133 Milano (Italy)], E-mail: leone.corradi@polimi.it; Di Marcello, Valentino; Luzzi, Lelio; Trudi, Fulvio [Politecnico di Milano - Department of Energy, Enrico Fermi Center for Nuclear Studies (CeSNEF), via Ponzio 34/3 - 20133 Milano (Italy)

    2009-08-15

    The collapse behavior of cylindrical shells pressurized from outside is examined. Attention is focused on tubes of moderate thickness, as required by very deep water pipelines or some innovative nuclear power plant proposals. Their collapse is expected to be dominated by yielding but, because of the decreasing nature of the post-collapse evolution, interaction with instability is likely to be significant enough to demand consideration. At present, no quantitative assessment of such effect is available, because little study has been devoted to tubes in this thickness range. Plasticity-instability interaction is activated by imperfections and to assess their influence on a systematic numerical study is undertaken. Computations produce a meaningful measure of the collapse pressure and it is proposed that the allowable pressure be determined on its basis, by introducing a suitable safety factor. This is chosen so that results reproduce those provided by presently accepted procedures in the well explored and reliable range of medium-thin tubes. When the same factor is applied to thicker tubes, the resulting allowable pressure is significantly higher than the values suggested by codes, which apparently react to the present lack of knowledge by assuming an extremely conservative attitude.

  4. Laboratory assessment of the hypertensive individual. Value of the main guidelines for high blood pressure

    Directory of Open Access Journals (Sweden)

    Reis Rafael S.

    1999-01-01

    Full Text Available OBJECTIVE: To determine if abnormal laboratory findings are more common in individuals with hypertension and in those with other risk factors, such as obesity, smoking and alcohol ingestion. METHODS: A study was carried out in the general outpatient clinics of a university hospital (145 individuals without previous diagnosis of hypertension and the following variables were assessed: high blood pressure (as defined by the VI Joint National Committee on Prevention, Detection and Treatment of High Blood Pressure - VI JNC, obesity [calculated using body mass index (BMI], tobacco use, and alcoholic ingestion. The laboratory examinations consisted of the following tests: hemogram, glycemia, uric acid, potassium, total/HDL-fraction cholesterol, triglycerides, calcium and creatinine. RESULTS: High blood pressure was not associated with a higher number of abnormal laboratory tests. Hypertensive individuals with a BMI > or = 25kg/m² or normotensive obese individuals, however, had a higher frequency of diabetes (12X, hypertriglyceridemia (3X, and hypercholesterolemia (2X, as compared with hypertensive individuals with BMI <25kg/m² and preobese/normal weight normotensive individuals. CONCLUSION: High blood pressure is not associated with a higher frequency of abnormal laboratory tests. The association of high blood pressure and obesity, however, increases the detection of diabetes and dyslipidemias.

  5. Imbalanced Gait Characteristics Based on Plantar Pressure Assessment in Patients with Hemiplegia

    Directory of Open Access Journals (Sweden)

    Suwaporn SANGHAN

    2014-10-01

    Full Text Available This study aimed to assess the plantar pressure and the gait characteristics in patients with hemiplegia compared with normal subjects. Plantar pressure was measured and evaluated by the Pedar-x system®. Twenty healthy Thai volunteers and 10 Thai patients with hemiplegia were recruited for this study. Patients with hemiplegia had significant differences in gait pattern and plantar pressure distribution compared with normal subjects. The percentages of the plantar pressure difference were 5 ± 3 and 30 ± 12 % in the normal group and the hemiplegic group, respectively. The time interval during single limb support on the affected side was 11 % shorter than the unaffected side while there was no difference of the time interval during single limb support in normal subjects. The pattern and area under the curve of normalized force-time relationship in patients with hemiplegia were particularly distinguishable from normal subjects. The progression lines of both feet were asymmetric in patients with hemiplegia but they were particularly symmetric in normal subjects. The gait characteristics derived from plantar pressure in patients with hemiplegia are apparently imbalanced and clearly different from that in normal subjects in both qualitative and quantitative aspects.

  6. Feasibility Assessment for Pressure Casting of Ceramic-Aluminum Composites for NASA's Propulsion Applications

    Science.gov (United States)

    Lee, Jonathan A.

    2005-01-01

    Feasibility assessment of pressure casting of ceramic-aluminum composites for NASA% propulsion applications is summarized. A combination of several demonstration projects to produce three unique components for liquid hydrogen-oxygen rocket engine% flanges, valves and turbo-pump housing are conducted. These components are made from boron carbide, silicon carbide and alumina powders fabricated into complex net shaped parts using dry green powder compaction, slip casting or a novel 3D ink-jet printing process, followed by sintering to produce performs that can be pressure cast by infiltration with molten aluminum. I n addition, joining techniques are also explored to insure that these components can be assembled into a structure without degrading their highly tailored properties. The feasibility assessment was made to determine if these new materials could provide a significant weight savings, thereby reducing vehicle launch costs, while being durable materials to increase safety and performance for propulsion system.

  7. Assessment of the risk of pressure ulcer development among hospitalized HIV/Aids patients.

    Science.gov (United States)

    Cidral, Silvana; Silva, Waldirene Fernandes; Visentin, Angelita; Borghi, Angela Cristina da Silva; Mantovani, Maria de Fátima; Hey, Ana Paula

    2016-01-01

    to assess the risk of pressure ulcer development among hospitalized HIV/Aids. Metod: study quantitative descriptive with 35 patients admitted to an infectious diseases hospital in Curitiba-PR-BR. Characterized clinical and epidemiological of patients using a data collection instrument and the Braden Scale. Data was compiled using Excel® and a simple descriptive analysis. two patients were found to have pressure ulcers and the most common comorbidities associated with HIV/Aids were pneumocystis pneumonia, caused by pneumocisti cariini (16), and pulmonary tuberculosis (13). The lowest scores were obtained in the friction and shear subscale, followed by the activity, nutrition, mobility and moisture subscales. The highest score was obtained in the sensory perception subscale. Two patients were classified as 'very high risk', six as 'high risk', three as 'low risk', and the rest as 'no risk'. risk assessment using scales provides objective information to assist with systemized and targeted nursing decision-making.

  8. Algorithmic Assessment of Vaccine-Induced Selective Pressure and Its Implications on Future Vaccine Candidates

    Directory of Open Access Journals (Sweden)

    Mones S. Abu-Asab

    2010-01-01

    Full Text Available Posttrial assessment of a vaccine's selective pressure on infecting strains may be realized through a bioinformatic tool such as parsimony phylogenetic analysis. Following a failed gonococcal pilus vaccine trial of Neisseria gonorrhoeae, we conducted a phylogenetic analysis of pilin DNA and predicted peptide sequences from clinical isolates to assess the extent of the vaccine's effect on the type of field strains that the volunteers contracted. Amplified pilin DNA sequences from infected vaccinees, placebo recipients, and vaccine specimens were phylogenetically analyzed. Cladograms show that the vaccine peptides have diverged substantially from their paternal isolate by clustering distantly from each other. Pilin genes of the field clinical isolates were heterogeneous, and their peptides produced clades comprised of vaccinated and placebo recipients' strains indicating that the pilus vaccine did not exert any significant selective pressure on gonorrhea field strains. Furthermore, sequences of the semivariable and hypervariable regions pointed out heterotachous rates of mutation and substitution.

  9. Risk assessment of a pressurized water reactor for Class 3-8 accidents

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.E.

    1979-10-01

    An assessment has been made of the impact on societal risk of Class 3-8 accident sequences as defined by Appendix D to 10 CFR50. The present analysis concentrates on a pressurized water reactor and utilizes realistic assumptions when practical. Conclusions are drawn as to the relative importance of the analyzed accidents and their impact on the development of a complete societal risk curve. 65 refs., 61 figs., 37 tabs.

  10. Assessment of the usability of a digital learning technology prototype for monitoring intracranial pressure

    Directory of Open Access Journals (Sweden)

    Lilian Regina de Carvalho

    Full Text Available ABSTRACT Objective: to assess the usability of a digital learning technology prototype as a new method for minimally invasive monitoring of intracranial pressure. Method: descriptive study using a quantitative approach on assessing the usability of a prototype based on Nielsen's ten heuristics. Four experts in the area of Human-Computer interaction participated in the study. Results: the evaluation delivered eight violated heuristics and 31 usability problems in the 32 screens of the prototype. Conclusion: the suggestions of the evaluators were critical for developing an intuitive, user-friendly interface and will be included in the final version of the digital learning technology.

  11. [Assessment of arterial wall stiffness by 24-hour blood pressure monitoring].

    Science.gov (United States)

    Korneva, V A; Kuznetsova, T Yu

    2016-01-01

    Arterial wall stiffness is an early marker of cardiovascular diseases. The gold standard for assessment of the stiffness of large vessels is presently pulse wave velocity (PWV). Work is in progress on the study of the reference values of PWV in people of different genders and ages. 24-hour blood pressure (BP) monitoring is not only a procedure that can estimate diurnal BP variability, but also monitor the indicators of vascular wall stiffness in a number of cases over a 24-hour period. The given review highlights the pathophysiology of arterial stiffness, methods for its assessment, and the aspects of use in therapeutic practice.

  12. Licensing assessment of the Candu Pressurized Heavy Water Reactor. Preliminary safety information document. Volume II. [USA

    Energy Technology Data Exchange (ETDEWEB)

    1977-06-01

    ERDA has requested United Engineers and Constructors (UE and C) to evaluate the design of the Canadian natural uranium fueled, heavy water moderated (CANDU) nuclear reactor power plant to assess its conformance with the licensing criteria and guidelines of the U.S. Nuclear Regulatory Commission (USNRC) for light water reactors. This assessment was used to identify cost significant items of nonconformance and to provide a basis for developing a detailed cost estimate for a 1140 MWe, 3-loop Pressurized Heavy Water Reactor (PHWR) located at the Middletown, USA Site.

  13. The Design of High Pressure Filling Xe Ionization Chamber and Electric Field Simulation%高气压充 Xe 电离室的设计与电场模拟

    Institute of Scientific and Technical Information of China (English)

    付睿玺; 曾国强; 葛良全

    2015-01-01

    设计了一种阳极为平板型的高压充Xe共栅阳极电离室。根据电离室Xe气的压强与施加电场关系,确定最佳气体密度和电场强度。在理论上推导与分析的基础上,获得电离室输出信号和电场分布的关系,从而对探测器结构进行优化设计。通过ansoftmaxwell 12模拟电场实验,采用加入保护环、施加不同阴极和收集极电压的方法对电场等势线分布进行优化,改善电荷收集区和非电荷收集区分布,提高了电离室的能量分辨率。%This paper presents a high -voltage Xe filling grid anode ionization chamber which the anodes are flat type.The best of the gas density and the electric field strength is determined by comparing the pressure of Xe gas and the applied electric field .Through theoretical derivation and analysis the signal mechanism of the ioni -zation chamber using coplanar grid anode technology is obtained , getting the relationship between electric field distribution and the output signal of ionization chamber , so as to optimize the structure of the detector .Ansoft-maxwell 12 is used to simulate the electric field in the experiments .By adding a guard ring and applying differ-ent anode and cathode voltage to optimizing the equipotential lines , it plays the role of improving charge and non-charge collection region and improves the energy resolution of the Ionization chamber .

  14. Universal CAGE-WANT Questionnaire: “Think & Fill in the Suspect, Self-Assess and Screen! You May Need Help For, What You Have Filled In!”

    Directory of Open Access Journals (Sweden)

    Deepak Gupta

    2014-12-01

    Full Text Available In 1970, John A. Ewing [1] developed CAGE questionnaire for identifying hidden alcoholism. It has been almost a half-century since 1970s [2] and CAGE questionnaire has expanded its promise and utility in identifying other addictions like for drug use as CAGE-AID in 1990s [3] and for personal electronic devices as University of Rochester Modified CAGE Questions in 2010s [4]. It seems the time is ripe to document a Universal CAGE Questionnaire (Table 1: Universal CAGE-WANT Questionnaire wherein any and every subject of fascination and/or any and every human urge to WANT can be incorporated for self-assessment and/or screening to identify addiction for the suspected and tested WANT.

  15. Assessing Radiation Pressure as a Feedback Mechanism in Star-forming Galaxies

    Science.gov (United States)

    Andrews, Brett H.; Thompson, Todd A.

    2011-02-01

    Radiation pressure from the absorption and scattering of starlight by dust grains may be an important feedback mechanism in regulating star-forming galaxies. We compile data from the literature on star clusters, star-forming subregions, normal star-forming galaxies, and starbursts to assess the importance of radiation pressure on dust as a feedback mechanism, by comparing the luminosity and flux of these systems to their dust Eddington limit. This exercise motivates a novel interpretation of the Schmidt law, the L IR-L'CO correlation, and the L IR-L'HCN correlation. In particular, the linear L IR-L'HCN correlation is a natural prediction of radiation pressure regulated star formation. Overall, we find that the Eddington limit sets a hard upper bound to the luminosity of any star-forming region. Importantly, however, many normal star-forming galaxies have luminosities significantly below the Eddington limit. We explore several explanations for this discrepancy, especially the role of "intermittency" in normal spirals—the tendency for only a small number of subregions within a galaxy to be actively forming stars at any moment because of the time dependence of the feedback process and the luminosity evolution of the stellar population. If radiation pressure regulates star formation in dense gas, then the gas depletion timescale is 6 Myr, in good agreement with observations of the densest starbursts. Finally, we highlight the importance of observational uncertainties, namely, the dust-to-gas ratio and the CO-to-H2 and HCN-to-H2 conversion factors, that must be understood before a definitive assessment of radiation pressure as a feedback mechanism in star-forming galaxies.

  16. Filling a Conical Cavity

    Science.gov (United States)

    Nye, Kyle; Eslam-Panah, Azar

    2016-11-01

    Root canal treatment involves the removal of infected tissue inside the tooth's canal system and filling the space with a dense sealing agent to prevent further infection. A good root canal treatment happens when the canals are filled homogeneously and tightly down to the root apex. Such a tooth is able to provide valuable service for an entire lifetime. However, there are some examples of poorly performed root canals where the anterior and posterior routes are not filled completely. Small packets of air can be trapped in narrow access cavities when restoring with resin composites. Such teeth can cause trouble even after many years and lead the conditions like acute bone infection or abscesses. In this study, the filling of dead-end conical cavities with various liquids is reported. The first case studies included conical cavity models with different angles and lengths to visualize the filling process. In this investigation, the rate and completeness at which a variety of liquids fill the cavity were observed to find ideal conditions for the process. Then, a 3D printed model of the scaled representation of a molar with prepared post spaces was used to simulate the root canal treatment. The results of this study can be used to gain a better understanding of the restoration for endodontically treated teeth.

  17. Pseudo-skin model for gravel-filled perforations

    Energy Technology Data Exchange (ETDEWEB)

    Onyekonwu, M.O. [Laser Engineering Consultants/Uniport, Port Harcourt (Nigeria); Okonkwo, F.C. [University of Port Harcourt Uniport, Port Harcourt (Nigeria)

    1997-11-05

    This paper discusses pressure losses due to flow in perforations filled with gravel or with formation material. These pressure losses are added to the pressure losses caused by convergence to perforations to obtain the pseudo-skin due to gravel-filled perforations. Calculation of the pressure loss due to convergence to perforation is discussed elsewhere. The flow in the perforation tunnel could be turbulent or laminar. Therefore, we calculated the pressure losses in a gravel-filled perforation using Forchheimer`s equation or Darcy`s law. However, we expect that the flow in such tunnels will be turbulent. Results from our model agree with experimental data published elsewhere. Also, our results show that pressure losses during flow through gravel-filled perforations could be substantial. Therefore, productivities of gravel pack completions may differ significantly from perforated completions in competent formation without gravel pack

  18. Analytical and computational methodology to assess the over pressures generated by a potential catastrophic failure of a cryogenic pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Zamora, I.; Fradera, J.; Jaskiewicz, F.; Lopez, D.; Hermosa, B.; Aleman, A.; Izquierdo, J.; Buskop, J.

    2014-07-01

    Idom has participated in the risk evaluation of Safety Important Class (SIC) structures due to over pressures generated by a catastrophic failure of a cryogenic pressure vessel at ITER plant site. The evaluation implements both analytical and computational methodologies achieving consistent and robust results. (Author)

  19. The urethral closure function in continent and stress urinary incontinent women assessed by urethral pressure reflectometry.

    Science.gov (United States)

    Saaby, Marie-Louise

    2014-02-01

    Stress urinary incontinence (SUI) occurs when the bladder pressure exceeds the urethral pressure in connection with physical effort or exertion or when sneezing or coughing and depends both on the strength of the urethral closure function and the abdominal pressure to which it is subjected. The urethral closure function in continent women and the dysfunction causing SUI are not known in details. The currently accepted view is based on the concept of a sphincteric unit and a support system. Our incomplete knowledge relates to the complexity of the closure apparatus and to inadequate assessment methods which so far have not provided robust urodynamic diagnostic tools, severity measures, or parameters to assess outcome after intervention. Urethral Pressure Reflectometry (UPR) is a novel method that measures the urethral pressure and cross-sectional area (by use of sound waves) simultaneously. The technique involves insertion of only a small, light and flexible polyurethane bag in the urethra and therefore avoids the common artifacts encountered with conventional methods. The UPR parameters can be obtained at a specific site of the urethra, e.g. the high pressure zone, and during various circumstances, i.e. resting and squeezing. During the study period, we advanced the UPR technique to enable faster measurement (within 7 seconds by the continuous technique) which allowed assessment during increased intra-abdominal pressure induced by physical straining. We investigated the urethral closure function in continent and SUI women during resting and straining by the "fast" UPR technique. Thereby new promising urethral parameters were provided that allowed characterization of the closure function based on the permanent closure forces (primarily generated by the sphincteric unit, measured by the Po-rest) and the adjunctive closure forces (primarily generated by the support system, measured by the abdominal to urethral pressure impact ratio (APIR)). The new parameters enabled

  20. Clinical assessment of auto-positive end-expiratory pressure by diaphragmatic electrical activity during pressure support and neurally adjusted ventilatory assist.

    Science.gov (United States)

    Bellani, Giacomo; Coppadoro, Andrea; Patroniti, Nicolò; Turella, Marta; Arrigoni Marocco, Stefano; Grasselli, Giacomo; Mauri, Tommaso; Pesenti, Antonio

    2014-09-01

    Auto-positive end-expiratory pressure (auto-PEEP) may substantially increase the inspiratory effort during assisted mechanical ventilation. Purpose of this study was to assess whether the electrical activity of the diaphragm (EAdi) signal can be reliably used to estimate auto-PEEP in patients undergoing pressure support ventilation and neurally adjusted ventilatory assist (NAVA) and whether NAVA was beneficial in comparison with pressure support ventilation in patients affected by auto-PEEP. In 10 patients with a clinical suspicion of auto-PEEP, the authors simultaneously recorded EAdi, airway, esophageal pressure, and flow during pressure support and NAVA, whereas external PEEP was increased from 2 to 14 cm H2O. Tracings were analyzed to measure apparent "dynamic" auto-PEEP (decrease in esophageal pressure to generate inspiratory flow), auto-EAdi (EAdi value at the onset of inspiratory flow), and IDEAdi (inspiratory delay between the onset of EAdi and the inspiratory flow). The pressure necessary to overcome auto-PEEP, auto-EAdi, and IDEAdi was significantly lower in NAVA as compared with pressure support ventilation, decreased with increase in external PEEP, although the effect of external PEEP was less pronounced in NAVA. Both auto-EAdi and IDEAdi were tightly correlated with auto-PEEP (r = 0.94 and r = 0.75, respectively). In the presence of auto-PEEP at lower external PEEP levels, NAVA was characterized by a characteristic shape of the airway pressure. In patients with auto-PEEP, NAVA, compared with pressure support ventilation, led to a decrease in the pressure necessary to overcome auto-PEEP, which could be reliably monitored by the electrical activity of the diaphragm before inspiratory flow onset (auto-EAdi).

  1. Mean Blood Pressure Assessment during Post-Exercise: Result from Two Different Methods of Calculation

    Directory of Open Access Journals (Sweden)

    Gianmarco Sainas, Raffaele Milia, Girolamo Palazzolo, Gianfranco Ibba, Elisabetta Marongiu, Silvana Roberto, Virginia Pinna, Giovanna Ghiani, Filippo Tocco, Antonio Crisafulli

    2016-09-01

    Full Text Available At rest the proportion between systolic and diastolic periods of the cardiac cycle is about 1/3 and 2/3 respectively. Therefore, mean blood pressure (MBP is usually calculated with a standard formula (SF as follows: MBP = diastolic blood pressure (DBP + 1/3 [systolic blood pressure (SBP – DBP]. However, during exercise this proportion is lost because of tachycardia, which shortens diastole more than systole. We analysed the difference in MBP calculation between the SF and a corrected formula (CF which takes into account changes in the diastolic and systolic periods caused by exercise-induced tachycardia. Our hypothesis was that the SF potentially induce a systematic error in MBP assessment during recovery after exercise. Ten healthy males underwent two exercise-recovery tests on a cycle-ergometer at mild-moderate and moderate-heavy workloads. Hemodynamics and MBP were monitored for 30 minutes after exercise bouts. The main result was that the SF on average underestimated MBP by –4.1 mmHg with respect to the CF. Moreover, in the period immediately after exercise, when sustained tachycardia occurred, the difference between SF and CF was large (in the order of -20-30 mmHg. Likewise, a systematic error in systemic vascular resistance assessment was present. It was concluded that the SF introduces a substantial error in MBP estimation in the period immediately following effort. This equation should not be used in this situation.

  2. Remaining life assessment of a high pressure turbine casing in creep and low cycle service regime

    Directory of Open Access Journals (Sweden)

    Bakić Gordana M.

    2014-01-01

    Full Text Available Thick walled components such as high pressure (HP steam turbine casings operating under high parameter conditions are subjected to a complex stress state. As a result of that stress state, some parts of HP turbine casing undergo to the creep fatigue caused by the combination of thermal fatigue resulted from repeated start/stop operation and the creep which occurs during long-term operation at high temperature and high-pressure. It is well known that domestic thermal power plants have been in use over 100000 h which means that significant cost is required not only for maintenance, but often for renewal of equipment. Based on comprehensive investigation, the results of residual life assessment of one high pressure steam turbine casing, which belongs to the older turbine generation, taking into account simultaneous action of thermal fatigue and creep, are presented in this paper. Also, the critical flaw crack size of HP turbine casing is determined because this parameter has a strong influence on casing integrity and residual life. The results of residual life assessment provide not only a basis for further maintenance, but also estimated time for reparation or renewal.

  3. Failure Assessment Methodologies for Pressure-Retaining Components under Severe Accident Loading

    Directory of Open Access Journals (Sweden)

    J. Arndt

    2012-01-01

    Full Text Available During postulated high-pressure core melt accident scenarios, temperature values of more than 800°C can be reached in the reactor coolant line and the surge line of a pressurised water reactor (PWR, before the bottom of the reactor pressure vessel experiences a significant temperature increase due to core melting. For the assessment of components of the primary cooling circuit, two methods are used by GRS. One is the simplified method ASTOR (approximated structural time of rupture. This method employs the hypothesis of linear damage accumulation for modeling damage progression. A failure time surface which is generated by structural finite element (FE analysis of varying pressure and temperature loads serves as a basis for estimations of failure times. The second method is to perform thermohydraulic and structure mechanic calculations for the accident scenario under consideration using complex calculation models. The paper shortly describes both assessment procedures. Validation of the ASTOR method concerning a large-scale test on a pipe section with geometric properties similar to a reactor coolant line is presented as well as severe accident scenarios investigated with both methods.

  4. Mean Blood Pressure Assessment during Post-Exercise: Result from Two Different Methods of Calculation.

    Science.gov (United States)

    Sainas, Gianmarco; Milia, Raffaele; Palazzolo, Girolamo; Ibba, Gianfranco; Marongiu, Elisabetta; Roberto, Silvana; Pinna, Virginia; Ghiani, Giovanna; Tocco, Filippo; Crisafulli, Antonio

    2016-09-01

    At rest the proportion between systolic and diastolic periods of the cardiac cycle is about 1/3 and 2/3 respectively. Therefore, mean blood pressure (MBP) is usually calculated with a standard formula (SF) as follows: MBP = diastolic blood pressure (DBP) + 1/3 [systolic blood pressure (SBP) - DBP]. However, during exercise this proportion is lost because of tachycardia, which shortens diastole more than systole. We analysed the difference in MBP calculation between the SF and a corrected formula (CF) which takes into account changes in the diastolic and systolic periods caused by exercise-induced tachycardia. Our hypothesis was that the SF potentially induce a systematic error in MBP assessment during recovery after exercise. Ten healthy males underwent two exercise-recovery tests on a cycle-ergometer at mild-moderate and moderate-heavy workloads. Hemodynamics and MBP were monitored for 30 minutes after exercise bouts. The main result was that the SF on average underestimated MBP by -4.1 mmHg with respect to the CF. Moreover, in the period immediately after exercise, when sustained tachycardia occurred, the difference between SF and CF was large (in the order of -20-30 mmHg). Likewise, a systematic error in systemic vascular resistance assessment was present. It was concluded that the SF introduces a substantial error in MBP estimation in the period immediately following effort. This equation should not be used in this situation.

  5. Selenium in ecosystems within the mountaintop coal mining and valley-fill region of southern West Virginia-assessment and ecosystem-scale modeling

    Science.gov (United States)

    Presser, Theresa S.

    2013-01-01

    Coal and associated waste rock are among environmental selenium (Se) sources that have the potential to affect reproduction in fish and aquatic birds. Ecosystems of southern West Virginia that are affected by drainage from mountaintop coal mines and valleys filled with waste rock in the Coal, Gauley, and Lower Guyandotte watersheds were assessed during 2010 and 2011. Sampling data from earlier studies in these watersheds (for example, Upper Mud River Reservoir) and other mining-affected watersheds also are included to assess additional hydrologic settings and food webs for comparison. Basin schematics give a comprehensive view of sampled species and Se concentration data specific to location and date. Food-web diagrams document the progression of Se trophic transfer across suspended particulate material, invertebrates, and fish for each site to serve as the basis for developing an ecosystem-scale model to predict Se exposure within the hydrologic conditions and food webs of southern West Virginia. This approach integrates a site-specific predator’s dietary exposure pathway into modeling to ensure an adequate link to Se toxicity and, thus, to species vulnerability. Site-specific fish abundance and richness data in streams documented various species of chub, shiner, dace, darters, bass, minnow, sunfish, sucker, catfish, and central stoneroller (Campostoma anomalum), mottled sculpin (Cottus bairdii), and least brook lamprey (Lampetra aepyptera). However, Se assessment species for streams, and hence, model species for streams, were limited to creek chub (Semotilus atromaculatus) and central stoneroller. Both of these species of fish are generally considered to have a high tolerance for environmental stress based on traditional comparative fish community assessment, with creek chub being present at all sites. Aquatic insects (mayfly, caddisfly, stonefly, dobsonfly, chironomid) were the main invertebrates sampled in streams. Collection of suspended particulate material

  6. Worldwide assessment of steam-generator problems in pressurized-water-reactor nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Woo, H.H.; Lu, S.C.

    1981-09-15

    Objective is to assess the reliability of steam generators of pressurized water reactor (PWR) power plants in the United States and abroad. The assessment is based on operation experience of both domestic and foreign PWR plants. The approach taken is to collect and review papers and reports available from the literature as well as information obtained by contacting research institutes both here and abroad. This report presents the results of the assessment. It contains a general background of PWR plant operations, plant types, and materials used in PWR plants. A review of the worldwide distribution of PWR plants is also given. The report describes in detail the degradation problems discovered in PWR steam generators: their causes, their impacts on the performance of steam generators, and the actions to mitigate and avoid them. One chapter is devoted to operating experience of PWR steam generators in foreign countries. Another discusses the improvements in future steam generator design.

  7. Dosimetry assessments for the reactor pressure vessel and core barrel in UK PWR plant

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, D.A.; Allen, D.A.; Huggon, A.P.; Picton, D.J.; Robinson, A.T.; Steadman, R.J. [Serco, Rutherford House, Quedgeley, Gloucester, Gl2 4NF (United Kingdom); Seren, T.; Lipponen, M.; Kekki, T. [VTT, Technical Research Centre of Finland, Otakaari 3 K, P.O. BOX 1000, Espoo, FI-02044 (Finland)

    2011-07-01

    Specimens for the Sizewell B reactor pressure vessel (RPV) inservice steels surveillance program are irradiated inside eight capsules located within the reactor pressure vessel and loaded prior to commissioning. The periodic removal of these capsules and testing of their contents provides material properties data at intervals during the lifetime of the plant. Neutron activation measurements and radiation transport calculations play an essential role in assessing the neutron exposure of the specimens and RPV. Following the most recent withdrawal, seven capsules have now been removed covering nine cycles of reactor operation. This paper summarizes the dosimetry results of the Sizewell B surveillance program obtained to date. In addition to an overview of the calculational methodology it includes a review of the measurements. Finally, it describes an extension of the methodology to provide dosimetry recommendations for the core barrel and briefly discusses the results that were obtained. (authors)

  8. Fourier Analysis of Peripheral Blood Pressure and Flow in Intraoperative Assessment of Infrainguinal Arterial Reconstructions

    Directory of Open Access Journals (Sweden)

    Cheshmedzhiev Mihail V.

    2014-08-01

    Full Text Available AIM: To assess infrainguinal arterial reconstructions by intraoperative flowmetry under the distal anastomosis using a fast Fourier transformation; calculate and compare the amplitude ratios of peripheral arterial blood pressure and volume flow before and after drug-induced vasodilation of occluded bypass grafts and bypass grafts that have been patent at least for 1 year. To find what magnitude of the change of these ratios indicate a long-term patency of the bypass grafting. PATIENTS AND METHODS: We compared the results of the intraoperative flowmetry tests of 97 patients with infrainguinal arterial reconstructions. The patients were divided into two groups based on the graft status: the grafts in 49 patients were patent for at least a year, and 48 patients had failed bypass. We used a fast Fourier transform (FFT of the pressure and blood flow waves and compared the ratios of their amplitudes before and after administration of a vasodilator drug into the graft. Comparing the ratios obtained before and those after administration of the drug we quantified their change in each group and analysed them. RESULTS: After a drug-induced vasodilation, the blood pressure and flow amplitude ratios for the group with compromised reconstructions were less than 1.9 times smaller than those before drug infusion, while for the group with bypass grafts that had been functional for at least 12 months the ratios declined by more than 1.9≈2 times. CONCLUSION: The magnitude of the change of amplitude ratios of the peripheral pressure and volume flow after drug-induced vasodilation can be used to make an assessment of the bypass graft and the distal arterial segment.

  9. Assessment of Eutrophication in Estuaries: Pressure-State-Response and Nitrogen Source Apportionment

    Science.gov (United States)

    Whitall, David; Bricker, Suzanne; Ferreira, Joao; Nobre, Ana M.; Simas, Teresa; Silva, Margarida

    2007-10-01

    A eutrophication assessment method was developed as part of the National Estuarine Eutrophication Assessment (NEEA) Program. The program is designed to improve monitoring and assessment of eutrophication in the estuaries and coastal bays of the United States with the intent to guide management plans and develop analytical and research models and tools for managers. These tools will help guide and improve management success for estuaries and coastal resources. The assessment method, a Pressure-State-Response approach, uses a simple model to determine Pressure and statistical criteria for indicator variables (where applicable) to determine State. The Response determination is mostly heuristic, although research models are being developed to improve that component. The three components are determined individually and then combined into a single rating. Application to several systems in the European Union (E.U.), specifically in Portugal, shows that the method is transferable, and thus is useful for development of management measures in both the Unites States and E.U. This approach identifies and quantifies the key anthropogenic nutrient input sources to estuaries so that management measures can target inputs for maximum effect. Because nitrogen is often the limiting nutrient in estuarine systems, examples of source identification and quantification for nitrogen have been developed for 11 coastal watersheds on the U.S. east coast using the WATERSN model. In general, estuaries in the Northeastern United States receive most of their nitrogen from human sewage, followed by atmospheric deposition. This is in contrast to some watersheds in the Mid-Atlantic (Chesapeake Bay) and South Atlantic (Pamlico Sound), which receive most of their nitrogen from agricultural runoff. Source identification is important for implementing effective management measures that should be monitored for success using assessment methods, as described herein. For instance, these results suggest that

  10. Fitness for purpose assessment after an over pressure incident at Arapuni Power Station

    Energy Technology Data Exchange (ETDEWEB)

    Firth, David; Briggs, Neil; Geoghegan, Bede; Dumbleton, Evan

    2004-06-01

    In December 2000 the wicket gates of Arapuni Unit G7 closed rapidly when a control arm separated from a shaft and the wickets were free to move. The unit had been operating under normal conditions at the time. The resulting overpressure pulse caused the lower portion of the penstock to become barrel shaped, and a longitudinal riveted joint partially failed. A significant amount of cracking was visible in the cast steel stay vanes and deformation had occurred at the rivets in the scroll case. A program of work was instigated to determine the cause of the failure, and its consequences, i.e. the pressures reached and what work was required to ensure that the unit was fit for reuse. The root cause of the failure was the design and fabrication of a control arm installed when the wicket gate control system had been modified. This control arm had two segments which clamped around a shaft. The clamping bolts used had seen a high residual bending load and cyclic loading. They failed in fatigue. The coating on the inside of the penstock and scroll casing was brittle and an assessment of the degree of craze cracking in the coating on tensile test specimens allowed an accurate method of determining the plastic strain that had occurred in the penstock, and hence the stress and applied pressure that occurred during the incident. The major issue was the condition of the stay vanes and the rivet holes in the scroll casing. The cracking in them was quantified by NDT inspection. Most of the cracks seen in the stay vanes were original casting defects that had not propagated during the overpressure. An engineering critical assessment was carried out in accordance with recognized international standards to determine the effects of defects under brittle fracture and overload conditions for a range of pressure conditions. An initial assessment was performed using conservative estimated values for the applied stresses and materials properties. The initial calculation indicated that the

  11. Developing a pressure ulcer risk assessment scale for patients in long-term care.

    Science.gov (United States)

    Lepisto, Mervi; Eriksson, Elina; Hietanen, Helvi; Lepisto, Jyri; Lauri, Sirkka

    2006-02-01

    Previous pressure ulcer risk assessment scales appear to have relied on opinions about risk factors and are based on care setting rather than research evidence. Utilizing 21 existing risk assessment scales and relevant risk factor literature, an instrument was developed by Finnish researchers that takes into account individual patient risk factors, devices and methods applied in nursing care, and organizational characteristics. The instrument underwent two pilot tests to assess the relevance and clarity of the instrument: the first involved 43 nurses and six patients; the second involved 50 nurses with expertise in wound care. Changes to questionnaire items deemed necessary as a result of descriptive analysis and agreement percentages were completed. After pilot testing, the final instrument addressed the following issues: 1) patient risks: activity, mobility in bed, mental status, nutrition, urinary incontinence, fecal incontinence, sensory perception, and skin condition; 2) devices and methods used in patient care: technical devices, bed type, mattress, overlay, seat cushions, and care methods; and 3) staff number and structure, maximum number of beds, and beds in use (the last group of questions were included to ensure participants understood the items; results were not analyzed). The phases of the study provided an expeditious means of data collection and a suitable opportunity to assess how the instrument would function in practice. Instrument reliability and validity were improved as a result of the pilot testing and can be enhanced further with continued use and assessment.

  12. Improving pressure ulcer risk assessment and management using the Waterlow scale at a London teaching hospital.

    Science.gov (United States)

    Mahalingam, S; Gao, L; Nageshwaran, S; Vickers, C; Bottomley, T; Grewal, P

    2014-12-01

    Pressure ulcers (PUs) cost the National Health Service (NHS) up to 4% of its health care expenditure. Arising from this are also clinical negligence claims, where inadequate risk assessment has been cited as one of the principal drawbacks in the prevention of PUs. This two-cycle audit aims to examine the consistency and accuracy of risk assessment of patients, and demonstrates how simple focused interventions can improve the quality of care provided. The Waterlow pressure ulcer risk assessment tool was employed to assess inpatients during a 6-month period at a London teaching hospital. Patients were risk assessed, and examined to detect PUs and to determine the type of mattress. We compared our findings with clinical (nursing and medical) documentation. Interventions were made through questionnaires given to staff, educational sessions, presentations and posters addressing where improvements could be made in risk stratifying patients. A repeat audit was carried out 24 months later and the results from both cycles were compared. Statistical analysis was carried out using Fisher's exact and the Student's T-test. In total 100 in-patients were assessed in each cycle with a mean age of 71.4 years in cycle 1 and 70.1 years in cycle 2. A nursing Waterlow score was recorded for 81% of patients in cycle 1 and 100% in cycle 2 (p<0.05). In cycle 1, the average nursing score was significantly lower than that from the study (mean 13.7 versus 17.1, median 14.0 versus 18.0; p<0.05), but after intervention this had reduced to a minimal difference (mean 8.5 versus 9.0, median 8.0 versus 9.0, p=0.08). Nursing scores recorded in the notes were lower than the study scores in cycle 1, primarily from a failure to appropriately assess certain categories of the Waterlow scale. These differences reduced after focused education of staff. Our results suggest that targeted interventions tailored towards nursing and medical staff can result in improvements in the risk assessment for prevention

  13. Using the resources framework to design, assess, and refine interventions on pressure in fluids

    Science.gov (United States)

    Young, Daniel E.; Meredith, Dawn C.

    2017-06-01

    The resources framework provides a useful and generative model of student thinking and learning. In particular, it suggests various strategies for instruction such as priming resources and refining intuition that allow students to build on knowledge they already have. In this paper, we describe the affordances of the resources framework in guiding the design, assessment, and refinement of interventions on pressure in fluids. This perspective kept us alert for cognitive resources on which students could build a deeper understanding and encouraged us to model student thinking as complex and context dependent, even on this narrow topic. This framework also facilitated a focus on evidence of productivity in student work as an alternative assessment to conceptual pre- and post testing.

  14. Nonconvective Forces: A Critical and Often Ignored Component in the Echocardiographic Assessment of Transvalvular Pressure Gradients

    Directory of Open Access Journals (Sweden)

    Michael S. Firstenberg

    2012-01-01

    Full Text Available Echocardiography is routinely used to assess ventricular and valvular function, particularly in patients with known or suspected cardiac disease and who have evidence of hemodynamic compromise. A cornerstone to the use of echocardiographic imaging is not only the qualitative assessment, but also the quantitative Doppler-derived velocity characteristics of intracardiac blood flow. While simplified equations, such as the modified Bernoulli equation, are used to estimate intracardiac pressure gradients based upon Doppler velocity data, these modified equations are based upon assumptions of the varying contributions of the different forces that contribute to blood flow. Unfortunately, the assumptions can result in significant miscalculations in determining a gradient if not completely understood or they are misapplied. We briefly summarize the principles of fluid dynamics that are used clinically with some of the inherent limitations of routine broad application of the simplified Bernoulli equation.

  15. Engineering failure assessment methods applied to pressurized components; Bruchmechanische Bewertung druckfuehrender Komponenten mittels ingenieurmaessiger Bewertungsverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Zerbst, U.; Beeck, F.; Scheider, I.; Brocks, W. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

    1998-11-01

    Under the roof of SINTAP (Structural Integrity Assessment Procedures for European Industry), a European BRITE-EURAM project, a study is being carried out into the possibility of establishing on the basis of existing models a standard European flaw assessment method. The R6 Routine and the ETM are important, existing examples in this context. The paper presents the two methods, explaining their advantages and shortcomes as well as common features. Their applicability is shown by experiments with two pressure vessels subject to internal pressure and flawed by a surface crack or a through-wall crack, respectively. Both the R6 Routine and the ETM results have been compared with results of component tests carried out in the 1980s at TWI and are found to yield acceptable conservative, i.e. sufficiently safe, lifetime predictions, as they do not give lifetime assessments which unduly underestimate the effects of flaws under operational loads. (orig./CB) [Deutsch] Gegenwaertig wird im Rahmen von SINTAP (Structural Integrity Assessment Procedures for European Industries), einem europaeischen BRITE-EURAM-Projekt geprueft, inwieweit auf der Grundlage vorhandener Modelle eine einheitliche europaeische Fehlerbewertungsmethode erstellt werden kann. Eine zentrale Stellung kommt dabei Verfahren wie der R6-Routine und dem ETM zu. In der vorliegenden Arbeit wurden beide Methoden vorgestellt, wobei ihre Vor- und Nachteile, aber auch ihre Gemeinsamkeiten herausgearbeitet wurden. Die Anwendung wurde an zwei innendruckbelasteten Behaeltern mit Oberflaechen- bzw. wanddurchdringendem Riss demonstriert. Sowohl R6-Routine als auch ETM ergaben im Vergleich mit am TWI zu Beginn der 80er Jahre durchgefuehrten Bauteilexperimenten eine vertretbare konservative Vorhersage, d.h. eine nicht allzu grosse Unterschaetzung der ertragbaren Last der Bauteile. (orig.)

  16. A Modelling Framework to Assess the Effect of Pressures on River Abiotic Habitat Conditions and Biota.

    Directory of Open Access Journals (Sweden)

    Jochem Kail

    Full Text Available River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a modelling framework was further developed and tested to assess the effect of pressures at different spatial scales on reach-scale habitat conditions and biota. Ecohydrological and 1D hydrodynamic models were used to predict discharge and water quality at the catchment scale and the resulting water level at the downstream end of a study reach. Long-term reach morphology was modelled using empirical regime equations, meander migration and 2D morphodynamic models. The respective flow and substrate conditions in the study reach were predicted using a 2D hydrodynamic model, and the suitability of these habitats was assessed with novel habitat models. In addition, dispersal models for fish and macroinvertebrates were developed to assess the re-colonization potential and to finally compare habitat suitability and the availability/ability of species to colonize these habitats. Applicability was tested and model performance was assessed by comparing observed and predicted conditions in the lowland Treene River in northern Germany. Technically, it was possible to link the different models, but future applications would benefit from the development of open source software for all modelling steps to enable fully automated model runs. Future research needs concern the physical modelling of long-term morphodynamics, feedback of biota (e.g., macrophytes on abiotic habitat conditions, species interactions, and empirical data on the hydraulic habitat suitability and dispersal abilities of macroinvertebrates. The modelling framework is flexible and allows for including additional models and investigating different research and management questions, e.g., in climate impact

  17. Unidirectional Expiratory Valve Method to Assess Maximal Inspiratory Pressure in Individuals without Artificial Airway.

    Directory of Open Access Journals (Sweden)

    Samantha Torres Grams

    Full Text Available Maximal Inspiratory Pressure (MIP is considered an effective method to estimate strength of inspiratory muscles, but still leads to false positive diagnosis. Although MIP assessment with unidirectional expiratory valve method has been used in patients undergoing mechanical ventilation, no previous studies investigated the application of this method in subjects without artificial airway.This study aimed to compare the MIP values assessed by standard method (MIPsta and by unidirectional expiratory valve method (MIPuni in subjects with spontaneous breathing without artificial airway. MIPuni reproducibility was also evaluated.This was a crossover design study, and 31 subjects performed MIPsta and MIPuni in a random order. MIPsta measured MIP maintaining negative pressure for at least one second after forceful expiration. MIPuni evaluated MIP using a unidirectional expiratory valve attached to a face mask and was conducted by two evaluators (A and B at two moments (Tests 1 and 2 to determine interobserver and intraobserver reproducibility of MIP values. Intraclass correlation coefficient (ICC[2,1] was used to determine intraobserver and interobserver reproducibility.The mean values for MIPuni were 14.3% higher (-117.3 ± 24.8 cmH2O than the mean values for MIPsta (-102.5 ± 23.9 cmH2O (p<0.001. Interobserver reproducibility assessment showed very high correlation for Test 1 (ICC[2,1] = 0.91, and high correlation for Test 2 (ICC[2,1] = 0.88. The assessment of the intraobserver reproducibility showed high correlation for evaluator A (ICC[2,1] = 0.86 and evaluator B (ICC[2,1] = 0.77.MIPuni presented higher values when compared with MIPsta and proved to be reproducible in subjects with spontaneous breathing without artificial airway.

  18. Unidirectional Expiratory Valve Method to Assess Maximal Inspiratory Pressure in Individuals without Artificial Airway

    Science.gov (United States)

    Grams, Samantha Torres; Kimoto, Karen Yumi Mota; Azevedo, Elen Moda de Oliveira; Lança, Marina; de Albuquerque, André Luis Pereira; de Brito, Christina May Moran; Yamaguti, Wellington Pereira

    2015-01-01

    Introduction Maximal Inspiratory Pressure (MIP) is considered an effective method to estimate strength of inspiratory muscles, but still leads to false positive diagnosis. Although MIP assessment with unidirectional expiratory valve method has been used in patients undergoing mechanical ventilation, no previous studies investigated the application of this method in subjects without artificial airway. Objectives This study aimed to compare the MIP values assessed by standard method (MIPsta) and by unidirectional expiratory valve method (MIPuni) in subjects with spontaneous breathing without artificial airway. MIPuni reproducibility was also evaluated. Methods This was a crossover design study, and 31 subjects performed MIPsta and MIPuni in a random order. MIPsta measured MIP maintaining negative pressure for at least one second after forceful expiration. MIPuni evaluated MIP using a unidirectional expiratory valve attached to a face mask and was conducted by two evaluators (A and B) at two moments (Tests 1 and 2) to determine interobserver and intraobserver reproducibility of MIP values. Intraclass correlation coefficient (ICC[2,1]) was used to determine intraobserver and interobserver reproducibility. Results The mean values for MIPuni were 14.3% higher (-117.3 ± 24.8 cmH2O) than the mean values for MIPsta (-102.5 ± 23.9 cmH2O) (p<0.001). Interobserver reproducibility assessment showed very high correlation for Test 1 (ICC[2,1] = 0.91), and high correlation for Test 2 (ICC[2,1] = 0.88). The assessment of the intraobserver reproducibility showed high correlation for evaluator A (ICC[2,1] = 0.86) and evaluator B (ICC[2,1] = 0.77). Conclusions MIPuni presented higher values when compared with MIPsta and proved to be reproducible in subjects with spontaneous breathing without artificial airway. PMID:26360255

  19. Effects of diaphragmatic control on the assessment of sniff nasal inspiratory pressure and maximum relaxation rate

    Science.gov (United States)

    Benício, Kadja; Dias, Fernando A. L.; Gualdi, Lucien P.; Aliverti, Andrea; Resqueti, Vanessa R.; Fregonezi, Guilherme A. F.

    2015-01-01

    OBJECTIVE: To assess the influence of diaphragmatic activation control (diaphC) on Sniff Nasal-Inspiratory Pressure (SNIP) and Maximum Relaxation Rate of inspiratory muscles (MRR) in healthy subjects. METHOD: Twenty subjects (9 male; age: 23 (SD=2.9) years; BMI: 23.8 (SD=3) kg/m2; FEV1/FVC: 0.9 (SD=0.1)] performed 5 sniff maneuvers in two different moments: with or without instruction on diaphC. Before the first maneuver, a brief explanation was given to the subjects on how to perform the sniff test. For sniff test with diaphC, subjects were instructed to perform intense diaphragm activation. The best SNIP and MRR values were used for analysis. MRR was calculated as the ratio of first derivative of pressure over time (dP/dtmax) and were normalized by dividing it by peak pressure (SNIP) from the same maneuver. RESULTS: SNIP values were significantly different in maneuvers with and without diaphC [without diaphC: -100 (SD=27.1) cmH2O/ with diaphC: -72.8 (SD=22.3) cmH2O; p<0.0001], normalized MRR values were not statistically different [without diaphC: -9.7 (SD=2.6); with diaphC: -8.9 (SD=1.5); p=0.19]. Without diaphC, 40% of the sample did not reach the appropriate sniff criteria found in the literature. CONCLUSION: Diaphragmatic control performed during SNIP test influences obtained inspiratory pressure, being lower when diaphC is performed. However, there was no influence on normalized MRR. PMID:26578254

  20. National assessment of the fragmentation, accessibility and anthropogenic pressure on the forests in Mexico

    Institute of Scientific and Technical Information of China (English)

    Rafael Moreno-Sanchez; Juan Manuel Torres-Rojo; Francisco Moreno-Sanchez; Sue Hawkins; Justin Little; Susan McPartland

    2012-01-01

    Forest managers and policy makers increasingly demand to have access to estimates of forest fragmentation,human accessibility to forest areas and levels of anthropogenic pressure on the remaining forests to integrate them into monitoring systems,management and conservation plans.Forest fragmentation is defined as the breaking up of a forest unit,where the number of patches and the amount of expose edge increase while the amount of core area decreases.Forest fragmentation studies in Mexico have been limited to local or regional levels and have concentrated only on specific forest types.This paper presents an assessment of the fragmentation of all forest types at the national level,their effective proximity to anthropogenic influences,and the development of an indicator of anthropogenic pressure on the forests areas.Broadleaf forests,tropical evergreen forests and tropical dry deciduous forests show the greatest fragmentation.Almost half (47%) of the tropical forests are in close effective proximity to anthropogenic influences and only 12% of their area can be considered isolated from anthropogenic influences.The values for the temperate forests are 23% and 29% respectively.Anthropogenic pressure in the immediate vicinity of anthropogenic activities is much higher in the tropical forests (75 in a scale 0-100) than in the temperate forests (30).When considering these results jointly,the tropical forests,and more specifically,the tropical evergreen forests and tropical dry deciduous forests are under the greatest pressure and risks of degradation.

  1. Assessment of the risk of pressure ulcer development among hospitalized HIV/Aids patients

    Directory of Open Access Journals (Sweden)

    Silvana Cidral

    2016-02-01

    Full Text Available ABSTRACT Objective: to assess the risk of pressure ulcer development among hospitalized HIV/Aids. Metod: study quantitative descriptive with 35 patients admitted to an infectious diseases hospital in Curitiba-PR-BR. Characterized clinical and epidemiological of patients using a data collection instrument and the Braden Scale. Data was compiled using Excel® and a simple descriptive analysis. Results: two patients were found to have pressure ulcers and the most common comorbidities associated with HIV/Aids were pneumocystis pneumonia, caused by pneumocisti cariini (16, and pulmonary tuberculosis (13. The lowest scores were obtained in the friction and shear subscale, followed by the activity, nutrition, mobility and moisture subscales. The highest score was obtained in the sensory perception subscale. Two patients were classified as 'very high risk', six as 'high risk', three as 'low risk', and the rest as 'no risk'. Conclusion: risk assessment using scales provides objective information to assist with systemized and targeted nursing decision-making.

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

    Directory of Open Access Journals (Sweden)

    Samuli Korpinen

    2016-08-01

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

  3. Application of the French codes to the pressurized thermal shocks assessment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mingya; Wang, Rong Shan; Yu, Weiwei; Lu, Feng; Zhang, Guo Dong; Xue, Fei; Chen, Zhilin [Suzhou Nuclear Power Research Institute, Life Management Center, Suzhou (China); Qian, Guian [Paul Scherrer Institute, Nuclear Energy and Safety Department, Villigen (Switzerland); Shi, Jinhua [Amec Foster Wheeler, Clean Energy Department, Gloucester (United Kingdom)

    2016-12-15

    The integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs) has been extensively studied. This paper introduces an integrity assessment of an RPV subjected to a PTS transient based on the French codes. In the USA, the 'screening criterion' for maximum allowable embrittlement of RPV material is developed based on the probabilistic fracture mechanics. However, in the French RCC-M and RSE-M codes, which are developed based on the deterministic fracture mechanics, there is no 'screening criterion'. In this paper, the methodology in the RCC-M and RSE-M codes, which are used for PTS analysis, are firstly discussed. The bases of the French codes are compared with ASME and FAVOR codes. A case study is also presented. The results show that the method in the RCC-M code that accounts for the influence of cladding on the stress intensity factor (SIF) may be nonconservative. The SIF almost doubles if the weld residual stress is considered. The approaches included in the codes differ in many aspects, which may result in significant differences in the assessment results. Therefore, homogenization of the codes in the long time operation of nuclear power plants is needed.

  4. Physics-Based Fragment Acceleration Modeling for Pressurized Tank Burst Risk Assessments

    Science.gov (United States)

    Manning, Ted A.; Lawrence, Scott L.

    2014-01-01

    As part of comprehensive efforts to develop physics-based risk assessment techniques for space systems at NASA, coupled computational fluid and rigid body dynamic simulations were carried out to investigate the flow mechanisms that accelerate tank fragments in bursting pressurized vessels. Simulations of several configurations were compared to analyses based on the industry-standard Baker explosion model, and were used to formulate an improved version of the model. The standard model, which neglects an external fluid, was found to agree best with simulation results only in configurations where the internal-to-external pressure ratio is very high and fragment curvature is small. The improved model introduces terms that accommodate an external fluid and better account for variations based on circumferential fragment count. Physics-based analysis was critical in increasing the model's range of applicability. The improved tank burst model can be used to produce more accurate risk assessments of space vehicle failure modes that involve high-speed debris, such as exploding propellant tanks and bursting rocket engines.

  5. Assessment of mechanical and three-body abrasive wear peculiarity of TiO$_2$- and ZnO-filled bi-directional E-glass fibre-based polyester composites

    Indian Academy of Sciences (India)

    AKANT KUMAR SINGH; SIDDHARTHA; DEEPAK

    2016-08-01

    This paper is about the development of bi-directional E-glass fibre-based polyester composites filled with zinc oxide (ZnO) and titanium dioxide (TiO$_2$) fillers, respectively. The mechanical characterization of these composites is performed. The three-body abrasive wear characteristic of fabricated composites has been assessed under different operating conditions. For this, the three-body abrasion test is done on dry abrasion test rig (TR-50)and analysed using Taguchi’s experimental design scheme and analysis of variance. The results obtained from these experiments are also validated against existing microscopic models of Ratner–Lancaster and Wang. A good linear relationship is obtained between specific wear rate and the reciprocal of ultimate strength and strain at tensile fracture of these composites. It indicates that the experimentally obtained results are in good agreement with theseexisting models. It is found that the tensile strength decreases with filler loading, while hardness, flexural strength, inter-laminar shear strength and impact strength are increased. TiO$_2$-filled composites were observed to performbetter than ZnO-filled composites under abrasive wear situations. The wear mechanism is studied in correlation with the SEM micrograph of the worn-out surface of composites. Performance optimization of composites is doneby using VIKOR method.

  6. Altered phase interactions between spontaneous blood pressure and flow fluctuations in type 2 diabetes mellitus: Nonlinear assessment of cerebral autoregulation

    Science.gov (United States)

    Hu, Kun; Peng, C. K.; Huang, Norden E.; Wu, Zhaohua; Lipsitz, Lewis A.; Cavallerano, Jerry; Novak, Vera

    2008-04-01

    Cerebral autoregulation is an important mechanism that involves dilatation and constriction in arterioles to maintain relatively stable cerebral blood flow in response to changes of systemic blood pressure. Traditional assessments of autoregulation focus on the changes of cerebral blood flow velocity in response to large blood pressure fluctuations induced by interventions. This approach is not feasible for patients with impaired autoregulation or cardiovascular regulation. Here we propose a newly developed technique-the multimodal pressure-flow (MMPF) analysis, which assesses autoregulation by quantifying nonlinear phase interactions between spontaneous oscillations in blood pressure and flow velocity during resting conditions. We show that cerebral autoregulation in healthy subjects can be characterized by specific phase shifts between spontaneous blood pressure and flow velocity oscillations, and the phase shifts are significantly reduced in diabetic subjects. Smaller phase shifts between oscillations in the two variables indicate more passive dependence of blood flow velocity on blood pressure, thus suggesting impaired cerebral autoregulation. Moreover, the reduction of the phase shifts in diabetes is observed not only in previously-recognized effective region of cerebral autoregulation (type 2 diabetes mellitus alters cerebral blood flow regulation over a wide frequency range and that this alteration can be reliably assessed from spontaneous oscillations in blood pressure and blood flow velocity during resting conditions. We also show that the MMPF method has better performance than traditional approaches based on Fourier transform, and is more suitable for the quantification of nonlinear phase interactions between nonstationary biological signals such as blood pressure and blood flow.

  7. Predictive capacity of risk assessment scales and clinical judgment for pressure ulcers: a meta-analysis.

    Science.gov (United States)

    García-Fernández, Francisco Pedro; Pancorbo-Hidalgo, Pedro L; Agreda, J Javier Soldevilla

    2014-01-01

    A systematic review with meta-analysis was completed to determine the capacity of risk assessment scales and nurses' clinical judgment to predict pressure ulcer (PU) development. Electronic databases were searched for prospective studies on the validity and predictive capacity of PUs risk assessment scales published between 1962 and 2010 in English, Spanish, Portuguese, Korean, German, and Greek. We excluded gray literature sources, integrative review articles, and retrospective or cross-sectional studies. The methodological quality of the studies was assessed according to the guidelines of the Critical Appraisal Skills Program. Predictive capacity was measured as relative risk (RR) with 95% confidence intervals. When 2 or more valid original studies were found, a meta-analysis was conducted using a random-effect model and sensitivity analysis. We identified 57 studies, including 31 that included a validation study. We also retrieved 4 studies that tested clinical judgment as a risk prediction factor. Meta-analysis produced the following pooled predictive capacity indicators: Braden (RR = 4.26); Norton (RR = 3.69); Waterlow (RR = 2.66); Cubbin-Jackson (RR = 8.63); EMINA (RR = 6.17); Pressure Sore Predictor Scale (RR = 21.4); and clinical judgment (RR = 1.89). Pooled analysis of 11 studies found adequate risk prediction capacity in various clinical settings; the Braden, Norton, EMINA (mEntal state, Mobility, Incontinence, Nutrition, Activity), Waterlow, and Cubbin-Jackson scales showed the highest predictive capacity. The clinical judgment of nurses was found to achieve inadequate predictive capacity when used alone, and should be used in combination with a validated scale.

  8. Microstructure Filled Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Moore, A. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thomas, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reese, T. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-24

    We propose replacing the gas fill in a hohlraum with a low average density, variable uniformity 3D printed structure. This creates a bimodal hohlraum which acts like a vacuum hohlraum initially during the picket, but could protect the capsule from glint or direct illumination, and then once expanded, homogenizes to behave like a variable z gas-fill during peak portion of the drive. This is motivated by a two main aims: 1) reduction of the Au bubble velocity to improve inner beam propagation, and 2) the introduction of a low density, high-Z, x-ray converter to improve x-ray production in the hohlraum and uniformity of the radiation field seen by the capsule.

  9. Complications of Dermal Filling

    Directory of Open Access Journals (Sweden)

    Sajad Ahmad Salati

    2011-11-01

    Full Text Available Dermal fillers have globally become sought after drugs due to the desire of aging population to regain the youthful looks without any surgical operations. But like other procedures, dermal filling can become complicated. Besides the profitability have introduced the factor of malpractice which can bring in misery rather than beauty and youthful body contours. This article briefly reviews the common adverse effects of dermal fillers.

  10. Patients' confidence in methods of blood pressure assessment and their reported adherence to antihypertensive medications.

    Science.gov (United States)

    Alvarez, Paul; Zeng, Jennifer; Tuttle, Laura; Viera, Anthony J

    2017-10-01

    Adherence to antihypertensive medications is often less than optimal. Research suggests that patients have limited confidence regarding whether office blood pressure (BP) assessments represent their 'true' BP, which may further promote poor adherence to BP-lowering medication. We assessed peoples' confidence in the methods of BP assessment and examined the associations between patients' confidence levels and medication adherence comparing office and home BP-monitoring techniques. We surveyed US adults aged 30 years or older (N=1010), all of whom had undergone an office BP measurement within the past 6 months. Respondents who indicated being prescribed antihypertensive medication (N=429) were asked to indicate their level of confidence on a 1-9 scale that BP measurements represented their true BP, and their adherence to antihypertensive medication using the eight-item Morisky Medical Adherence Scale (MMAS-8). Respondents had equal confidence that both office BP measurements and home monitoring measurements reflected their true BP (median=7). Respondents indicated that they would have slightly more confidence in ambulatory BP monitoring (median=8). As respondents' confidence in the assessments of BP from office measurements and home monitoring increased from 1 to 9, the mean MMAS-8 score, adjusted for age, race, and education, increased from 5.38 to 6.25 (P=0.053) and from 5.50 to 6.14 (P=0.25), respectively. As patients' confidence in a BP assessment method increases, so too does their reported adherence to prescribed antihypertensive medications. This finding further supports the incorporation of methods in which patients can feel confident that the measurements are representative of their 'true' BP.

  11. Assessing intravascular volume by difference in pulse pressure in pigs submitted to graded hemorrhage.

    Science.gov (United States)

    Pestel, Gunther J; Hiltebrand, Luzius B; Fukui, Kimiko; Cohen, Delphine; Hager, Helmut; Kurz, Andrea M

    2006-10-01

    We assessed changes in intravascular volume monitored by difference in pulse pressure (dPP%) after stepwise hemorrhage in an experimental pig model. Six pigs (23-25 kg) were anesthetized (isoflurane 1.5 vol%) and mechanically ventilated to keep end-tidal CO2 (etCO2) at 35 mmHg. A PA-catheter and an arterial catheter were placed via femoral access. During and after surgery, animals received lactated Ringer's solution as long as they were considered volume responders (dPP>13%). Then animals were allowed to stabilize from the induction of anesthesia and insertion of catheters for 30 min. After stabilization, baseline measurements were taken. Five percent of blood volume was withdrawn, followed by another 5%, and then in 10%-increments until death from exsanguination occurred. After withdrawal of 5% of blood volume, all pigs were considered volume responders (dPP>13%); dPP rose significantly from 6.1+/-3.3% to 19.4+/-4.2%. The regression analysis of stepwise hemorrhage revealed a linear relation between blood loss (hemorrhage in %) and dPP (y=0.99*x+14; R2=0.7764; P<.0001). In addition, dPP was the only parameter that changed significantly between baseline and a blood loss of 5% (P<0.01), whereas cardiac output, stroke volume, heart rate, MAP, central venous pressure, pulmonary artery occlusion pressure, and systemic vascular resistance, respectively, remained unchanged. We conclude that in an experimental hypovolemic pig model, dPP correlates well with blood loss.

  12. Laboratory and clinical tests of a prototype pressure sensor for clincial assessment of prosthetic socket fit.

    Science.gov (United States)

    Polliack, A A; Craig, D D; Sieh, R C; Landsberger, S; Mcneal, D R

    2002-04-01

    Lower limb prosthetic socket fabrication is a highly refined process relying on the prosthetist's skill and experience. Despite their best efforts, patients often return with complications. Additionally, clinical application of technological advances for the quantification of biomechanical factors at the socket interface has not changed in practice. Measuring pressure levels at the stump/socket interface could provide valuable information in the process of prosthetic socket fabrication, fit and modification. This paper presents findings on the performance of a prototype capacitance pressure sensor designed for prosthetic socket use. Bench tests using compressed air were performed to measure accuracy, hysteresis and drift responses in both a flatbed chamber and a custom-modified pressure vessel. For the contoured testing, the sensors were placed on nine sites on a positive trans-tibial stump mould and enveloped with a silicone liner. Additionally, a preliminary clinical evaluation was performed with two trans-tibial amputee subjects at the nine sites during normal ambulation. Bench test results showed that the prototype capacitance sensor performed well in all categories, exhibiting a 2.42% (flatbed) and 9.96% (contoured) accuracy error, a 12.93% (flatbed) and 12.95% (contoured) hysteresis error, and a 4.40% (flatbed) and 6.20% (contoured) drift error. The clinical study showed that after three hours of continual use, no noticeable sensor drift occurred between pre and post-test calibration values. The results from this study were encouraging and the authors hope to conduct further laboratory and clinical trials to assess the influence of shear force and dynamic loading on sensor response.

  13. Assessment of Field Experience Related to Pressurized Water Reactor Primary System Leaks

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Vikram Naginbhai; Ware, Arthur Gates; Atwood, Corwin Lee; Sattison, Martin Blaine; Hartley, Robert Scott; Hsu, C.

    1999-08-01

    This paper presents our assessment of field experience related to pressurized water reactor (PWR) primary system leaks in terms of their number of rates, how aging affects frequency of leak events, the safety significance of such leaks, industry efforts to reduce leaks, and effectiveness of current leak detection systems. We have reviewed the licensee event reports to identify the events that took place during 1985 to the third quarter of 1996, and reviewed related technical literature and visited PWR plants to analyze these events. Our assessment shows that USNRC licensees have taken effective actions to reduce the number of leak events. One main reason for this decreasing trend was the elimination or reportable leakages from valve stem packing after 1991. Our review of leak events related to vibratory fatigue reveals a statistically significant decreasing trend with age (years of operation), but not in calendar time. Our assessment of worldwide data on leakage caused by thermal fatigue cracking is that the fatigue of aging piping is a safety significant issue. Our review of leak events has identified several susceptible sites in piping having high safety significance; but the inspection of some of these sites is not required by the ASME Code. These sites may be included in the risk-informed inspection programs.

  14. Assessment of Field Experience Related to Pressurized Water Reactor Primary System Leaks

    Energy Technology Data Exchange (ETDEWEB)

    A. G. Ware; C. Hsu (USNRC); C. L. Atwood; M. B. Sattison; R. S. Hartley (INEEL); V. N. Shah

    1999-02-01

    This paper presents our assessment of field experience related to pressurized water reactor (PWR) primary system leaks in terms of their number and rates, how aging affects frequency of leak events, the safety significance of such leaks, industry efforts to reduce leaks, and effectiveness of current leak detection systems. We have reviewed the licensee event reports to identify the events that took place during 1985 to the third quarter of 1996, and reviewed related technical literature and visited PWR plants to analyze these events. Our assessment shows that USNRC licensees have taken effective actions to reduce the number of leak events. One main reason for this decreasing trend was the elimination or reportable leakages from valve stem packing after 1991. Our review of leak events related to vibratory fatigue reveals a statistically significant decreasing trend with age (years of operation), but not in calendar time. Our assessment of worldwide data on leakage caused by thermal fatigue cracking is that the fatigue of aging piping is a safety significant issue. Our review of leak events has identified several susceptible sites in piping having high safety significance; but the inspection of some of these sites is not required by the ASME Code. These sites may be included in the risk-informed inspection programs.

  15. The assessment of velopharyngeal function using nasal ram pressure testing following palatoplasty.

    Science.gov (United States)

    Krochmal, Daniel J; Zajac, David J; Alhudaib, Omar M; Emodi, Omri; van Aalst, John A

    2013-09-01

    Objective : To compare nasal ram pressure (NRP) data with perceptual speech assessments in young children following palatoplasty. Design and Setting : NRP monitoring, a noninvasive technique using a two-pronged nasal cannula that detects nasal airflow during speech, was performed on patients 12 months following palatoplasty in our Craniofacial Center. Patients : Eighteen English-speaking nonsyndromic patients, aged 21 to 28 months, without hearing or language deficits, underwent NRP testing. Main Outcome Measured : During NRP measurement, the number of oral stop consonants produced spontaneously or following prompts was recorded. Stops were considered produced with velopharyngeal closure if NRP demonstrated no nasal airflow. The percentage of closed stops as measured by NRP was compared to the clinical assessment by craniofacial team speech-language pathologists. Results : Eight patients achieved 100% stop closure. Four patients obtained 90% to 96% stop closure. Three patients had stop closure of 85%, 78%, and 50%. Three patients had 0% stop closure; two of these patients subsequently underwent secondary palatal surgery. No significant clinical speech deficits were noted in patients with >90% closure. No association with defect size or cleft type was identified. Conclusions : NRP monitoring is well-tolerated in young children following palatoplasty. Achieving velopharyngeal (VP) closure for >90% of stops is associated with a clinical assessment of adequate speech and VP function. Postoperative NRP testing may serve as a useful adjunct to clinical speech evaluation for early identification of children who require more intensive speech therapy or secondary palatal surgery.

  16. Assessment of intraocular pressure sensing using an implanted reflective flexible membrane

    Science.gov (United States)

    Nazarov, Andrey; Knyazer, Boris; Lifshitz, Tova; Schvartzman, Mark; Abdulhalim, Ibrahim

    2017-04-01

    Glaucoma is a neurodegenerative condition that is the leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is the main cause for the development of the disease. The symptoms of this form, such as deterioration of vision and scotomas (loss of visual fields), appear in the latter stages of the disease. Therefore, an IOP monitoring device is needed for better, simpler, and faster diagnosis, and to enable a fast treatment response. We present a theoretical assessment as well as preliminary experimental results of a simple approach for easy, optical, IOP self-monitoring. It is based on a polydimethylsiloxane membrane coated with a reflective layer and a Hartmann-Shack wavefront sensor. Nearly linear correlation is found between membrane deformation and Zernike coefficients representing defocus primary spherical aberration, with high sensitivity and negligible dependence on the measurement distance. The proposed device is expected to provide an accurate IOP measurement resolution of less than ±0.2 mm Hg with a pressure dependence on working distances <0.7 mm Hg/cm for a thick membrane; the corresponding values for a thin membrane are ±0.45 mm Hg and <0.6 mm Hg/cm, respectively, at typical IOP values-up to 40 mm Hg.

  17. Conventional deep pressure algometry is not suitable for clinical assessment of nociception in painless diabetic neuropathy

    Directory of Open Access Journals (Sweden)

    Ernst A. Chantelau

    2016-09-01

    Full Text Available Background: In diabetic persons with painless neuropathic foot ulceration, foot skin was found to be insensate to noxious pinprick stimulation (stimulation area less than 0.05 mm2, while compression of deep subcutaneous foot tissues by Algometer II® (stimulation area 1 cm2 could evoke a deep dull aching. To elucidate this discrepancy, the Algometer II stimulation technique was critically reviewed by varying probe sizes and anatomical sites in the same study population 3 years later. Methods: Ten control subjects without neuropathy and 11 persons with painless diabetic neuropathy (PLDN, seven of whom with diabetic foot syndrome, i.e., past painless foot ulcer, or inactive Charcot arthropathy were re-examined using Algometer II. Deep pressure pain perception threshold (DPPPT was measured in random sequence with stimulation areas of 0.5 cm2, 1 cm2, and 2 cm2 (separated by 5 min intervals, at the plantar forefoot, the instep, and the hindfoot of both legs. Results: In the control and PLDN groups, median DPPPTs differed significantly between stimulation areas (highest with 0.5 cm2, intermediate with 1 cm2, lowest with 2 cm2; p<0.001, and varied moderately by anatomical site. Between-group differences were relatively small. Results of the 1 cm2 assessments repeated 3 years apart were similar. Conclusions: Algometer II readings represent spatial summation of low-threshold pressure-receptor rather than of high-threshold nociceptor stimulation and are, thus, unhelpful for assessing PLDN. Reproducibility of the measurements is good.

  18. Clinical Evaluation of a New Pressure Ulcer Risk Assessment Instrument, the Pressure Ulcer Risk Primary or Secondary Evaluation Tool (PURPOSE T).

    Science.gov (United States)

    Coleman, Susanne; Smith, Isabelle L; McGinnis, Elizabeth; Keen, Justin; Muir, Delia; Wilson, Lyn; Stubbs, Nikki; Dealey, Carol; Brown, Sarah; Nelson, E Andrea; Nixon, Jane

    2017-08-23

    To test the psychometric properties and clinical usability of a new Pressure Ulcer Risk Assessment Instrument including inter-rater and test-retest reliability, convergent validity and data completeness. Methodological and practical limitations associated with traditional Pressure Ulcer Risk Assessment Instruments, prompted a programme to work to develop a new instrument, as part of the National Institute for Health Research funded, Pressure UlceR Programme Of reSEarch (RP-PG-0407-10056). Observational field test. For this clinical evaluation 230 patients were purposefully sampled across four broad levels of pressure ulcer risk with representation from 4 secondary care and 4 community NHS Trusts in England. Blinded and simultaneous paired (ward/community nurse and expert nurse) PURPOSE-T assessments were undertaken. Follow-up retest was undertaken by the expert nurse. Field notes of PURPOSE-T use were collected. Data were collected October 2012-Jan 2013. The clinical evaluation demonstrated 'very good' (kappa) inter-rater and test-retest agreement for PURPOSE-T assessment decision overall. The percentage agreement for 'problem/no problem' was over 75% for the main risk factors. Convergent validity demonstrated moderate to high associations with other measures of similar constructs. The PURPOSE-T evaluation facilitated the initial validation and clinical usability of the instrument and demonstrated that PURPOSE-T is suitable of use in clinical practice. Further study is needed to evaluate the impact of using the instrument on care processes and outcomes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  19. Risks assessment of water pollution by pesticides at local scale (PESTEAUX project): study of polluting pressure.

    Science.gov (United States)

    Noel, Stéphanie; Billo Bah, Boubacar

    2009-01-01

    Pollution of water resources (surface waters and ground waters) by pesticide uses is one of the key point of the European policy with the implementation of the Water Frame Work Directive (2000/60/EC) and the thematic Strategy on the Sustainable use of pesticides. According to this legislation, the Member States must initiate measures to limit environmental and toxicological effects caused by pesticide uses. The Agricultural Research Centre of Wallonia (CRA-W) emphasized the need of a tool for spatial risk analysis and develOPs it within the framework of PESTEAUX project. The originality of the approach proposed by the CRA-W is to generate maps to identify the risk of pollution at locale scale (agricultural parcel). The risk will be assessed according to the study of different factors, grouped under 3 data's layers: polluting pressure, vulnerability of the physical environment (soil) and meteorological data. This approach is directly based on the risk's definition which takes into account the polluting pressure, linked to the human activities, and the vulnerability of the soil, defined by factors of physical environment which characterize the water flow in the parcel. Moreover, meteorological data influence the intensity and likelihood flow of water, and indirectly pesticide by leaching or runoff. The PESTEAUX's approach to study the pollution is based on the model "source-vector-target". The source is the polluting pressure, in other words, the pesticides which could reach the targets. The main vector is the water which vehicles the pesticide on and trough the soil until the target which are the surface waters or ground waters. In this paper we introduce the factors contributing to the polluting pressure. These factors are linking to the human activities and more precisely, to the pesticide uses. The factors considered have an influence on pesticide's transport by water (in its solid state or in dissolved state by leaching, run-off, or erosion) but also on a set of

  20. Assessment of the canal fillings using cone beam computed tomography and digital periapical radiography%锥形束CT与数字化根尖片对根充效果的评价

    Institute of Scientific and Technical Information of China (English)

    何辰菲; 邹德荣

    2015-01-01

    目的:比较锥形束CT(CBCT)与根尖片对根管充填后效果的评价,进一步探讨CBCT在根管治疗中的优势及应用价值。方法选取经临床诊断需要进行根管治疗的100颗患牙(221例根管),根管充填后同步拍摄根尖片与CBCT,术后分别由2位经验丰富的临床医生从根管充填的有效长度与严密程度两方面进行读片,运用卡方检验比较2种方法是否在评价结果上存在差异性。结果总计充填根管214例,充填遗漏7例,在根管充填长度、严密程度及满意程度评价方面,分别约有34.58%、30.48%和37.58%的根管在数字化根尖片与CBCT的评价结果上未能达成一致意见,经过统计学检验,数字化根尖片与CBCT在上述三方面的评价均有高度显著性差异(P <0.01)。结论 CBCT较根尖片在根管治疗术的长度及严密程度评价方面更为灵敏及准确,在复杂或疑难的根管治疗术中拥有很高的临床应用价值。%Objective To compare the root filling quality assessed by cone-beam computed tomography (CBCT)and periapical radio-graphs (PA),and to explore the advantage and application value of CBCT in the root canal treatment. Methods In total,100 teeth (221 canals)were clinically diagnosed and received root canal therapy. After root canal filling,the length and density of root filling were as-sessed with PA and CBCT simultaneously by two experienced endodontists. Chi-square test was performed with the data from PA or CBCT to evaluate the quality of the root filling. Results In total,214 canals received root-canal treatment while 7 canals were omitted. In terms of length,density and satisfaction of the root filling,there were about 34. 58%,30. 48% and 37. 58% of canals demonstrated different re-sults based on the evaluation from PA and CBCT respectively. According to the result of statistical test,PA and CBCT had significant differences (P <0. 01)in the assessment of the three

  1. Study on new technique of rapidly following curtain filling

    Institute of Scientific and Technical Information of China (English)

    余健; 张爱兰

    2002-01-01

    The present problem of mining of narrow and gentle dip vein was analyzed. A new technique of rapidly following curtain filling was put forward. The results show that the new technique is feasible, has the characteristic to make the whole curtain wall filter, makes relative density of the filling tailings slurry reach saturation of 78.0%-80.0% in 25 min, and keeps the roof of mined-out space stable in 60 min. The new technique of the rapidly following curtain filling has solved the difficult problem of the filling body filtering slowly and promptly controlling underground pressure, which cannot be solved in traditional ways.

  2. Assessment of respiratory system compliance with electrical impedance tomography using a positive end-expiratory pressure wave maneuver during pressure support ventilation: a pilot clinical study.

    Science.gov (United States)

    Becher, Tobias H; Bui, Simon; Zick, Günther; Bläser, Daniel; Schädler, Dirk; Weiler, Norbert; Frerichs, Inéz

    2014-12-10

    Assessment of respiratory system compliance (Crs) can be used for individual optimization of positive end-expiratory pressure (PEEP). However, in patients with spontaneous breathing activity, the conventional methods for Crs measurement are inaccurate because of the variable muscular pressure of the patient. We hypothesized that a PEEP wave maneuver, analyzed with electrical impedance tomography (EIT), might be suitable for global and regional assessment of Crs during assisted spontaneous breathing. After approval of the local ethics committee, we performed a pilot clinical study in 18 mechanically ventilated patients (61 ± 16 years (mean ± standard deviation)) who were suitable for weaning with pressure support ventilation (PSV). For the PEEP wave, PEEP was elevated by 1 cmH2O after every fifth breath during PSV. This was repeated five times, until a total PEEP increase of 5 cmH2O was reached. Subsequently, PEEP was reduced in steps of 1 cmH2O in the same manner until the original PEEP level was reached. Crs was calculated using EIT from the global, ventral and dorsal lung regions of interest. For reference measurements, all patients were also examined during controlled mechanical ventilation (CMV) with a low-flow pressure-volume maneuver. Global and regional Crs(low-flow) was calculated as the slope of the pressure-volume loop between the pressure that corresponded to the selected PEEP and PEEP +5 cmH2O. For additional reference, Crs during CMV (Crs(CMV)) was calculated as expired tidal volume divided by the difference between airway plateau pressure and PEEP. Respiratory system compliance calculated from the PEEP wave (Crs(PEEP wave)) correlated closely with both reference measurements (r = 0.79 for Crs(low-flow) and r = 0.71 for Crs(CMV)). No significant difference was observed between the mean Crs(PEEP wave) and the mean Crs(low-flow). However, a significant bias of +17.1 ml/cmH2O was observed between Crs(PEEP wave) and Crs(CMV). Analyzing a PEEP wave

  3. 基于熵权和综合指数模型的充填管道堵塞风险性评价%Risk assessment on blocking of filling pipeline based on comprehensive index and entropy

    Institute of Scientific and Technical Information of China (English)

    张钦礼; 曹瑞锋; 王石; 刘奇; 何洪涛

    2013-01-01

    In order to assess blocking risk of filling pipe system in deep mine , a comprehensive in-dex model of filling pipeline blocking was established on the basis of the entropy theory .Regarding Longshou mine of Jinchuan company , Dahongshan copper mine , Hedong gold mine and Xincheng gold mine as the evaluation objects for blocking risk of filling pipeline , ten evaluation indicators were selected as the discriminant index of the comprehensive model .The corresponding matrix was estab-lished according to the in-situ data of the mines and the three evaluation standard of blocking risk of filling pipelines.The entropy theory was used to calculate the weight of each discriminant index , and the predictive blocking risk of filling pipelines was finally obtained and sorted using the rule of comprehensive index model .The results show that the blocking risk of Longshou mine of Jinchuan company is lower than level Ⅱ, and the blocking risk of Hedong gold mine , Xincheng gold mine and Dahongshan copper mine is lower than level Ⅲ.It was followed that the blocking risk of filling pipeline of Longshou mine of Jinchuan company is significantly greater than that of the rest three mines, and the difference among the blocking risk of filling pipeline of the other three mines is small.The comprehensive index model based on the entropy theory can reflect the distance between the sample and the evaluation standard , and the evaluation is objective , reasonable , and practica-ble .%为预测深井矿山充填管道输送系统堵塞的难易程度,基于熵权理论建立充填管道堵塞风险综合指数模型。以金川龙首矿、大红山铜矿、河东金矿和新城金矿作为充填管道堵塞风险评价模型的对象,选取10项评价指标作为综合指数模型的判别指标,根据矿山实测数据和管道堵塞风险三级评价标准建立对应矩阵,并利用熵权理论获得各判别指标的权重,依照综合指数模型计算得到充填管道

  4. Assessment of high blood pressure patients in the third year’s Surgical Clinic of the Dentistry course at Cesumar

    OpenAIRE

    Menin, Cristiane; Bortoloto, Flávia Gongora; Gustavo Jacobucci FARAH; Filho, Liogi Iwaki; Iwaki, Lílian Cristina Vessoni; Leite, Pablo C. Comelli; Gentini, Raquel Forlani

    2007-01-01

    With the increase of arterial hypertension in the Brazilian population, it has become essential to point out to undergraduate students the need for a thorough clinical examination of patients, and the special care with high blood pressure patients, especially in a surgical clinic where complications may be severe. The objective of this work has been to assess the number of high blood pressure patients that come the Surgical Clinic of the Dentistry course of CESUMAR, and find out if these pati...

  5. Impact of fill-level in twin-screw granulation on critical quality attributes of granules and tablets.

    Science.gov (United States)

    Meier, Robin; Moll, Klaus-Peter; Krumme, Markus; Kleinebudde, Peter

    2017-02-15

    In a previous study a change of the fill-level in the barrel exerted a huge influence on the twin-screw granulation (TSG) process of a high drug loaded, simplified formulation. The present work investigated this influence systematically. The specific feed load (SFL) indicating the mass per revolution as surrogate parameter for the fill-level was applied and the correlation to the real volumetric fill level of an extruder could be demonstrated by a newly developed method. A design of experiments was conducted to examine the combined influence of SFL and screw speed on the process and on critical quality attributes of granules and tablets. The same formulation was granulated at constant liquid level with the same screw configuration and led to distinctively different results by only changing the fill-level and the screw speed. The power consumption of the extruder increased at higher SFLs with hardly any influence of screw speed. At low SFL the median residence time was mainly fill-level dependent and at higher SFL mainly screw speed dependent. Optimal values for the product characteristics were found at medium values for the SFL. Granule size distributions shifted from mono-modal and narrow shape to broader and even bimodal distributions of larger median granule sizes, when exceeding or falling below a certain fill-level. Deviating from the optimum fill-level, tensile strength of tablets decreased by about 25 % and disintegration times of tablets increased for more than one third. At low fill-levels, material accumulation in front of the kneading zone was detected by pressure measurements and was assumed to be responsible for the unfavored product performance. At high fill-levels, granule consolidation due to higher propensity of contact with the result of higher material temperature was accounted for inferior product performance. The fill-level was found to be an important factor in assessment and development of twin-screw granulation processes as it impacted

  6. Assessing anthropogenic pressures on estuarine fish nurseries along the Portuguese coast: a multi-metric index and conceptual approach.

    Science.gov (United States)

    Vasconcelos, R P; Reis-Santos, P; Fonseca, V; Maia, A; Ruano, M; França, S; Vinagre, C; Costa, M J; Cabral, H

    2007-03-15

    Estuaries are among the most productive ecosystems and simultaneously among the most threatened by conflicting human activities which damage their ecological functions, namely their nursery role for many fish species. A thorough assessment of the anthropogenic pressures in Portuguese estuarine systems (Douro, Ria de Aveiro, Mondego, Tejo, Sado, Mira, Ria Formosa and Guadiana) was made applying an aggregating multi-metric index, which quantitatively evaluates influences from key components: dams, population and industry, port activities and resource exploitation. Estuaries were ranked from most (Tejo) to least pressured (Mira), and the most influential types of pressure identified. In most estuaries overall pressure was generated by a dominant group of pressure components, with several systems being afflicted by similar problematic sources. An evaluation of the influence of anthropogenic pressures on the most important sparidae, soleidae, pleuronectidae, moronidae and clupeidae species that use these estuaries as nurseries was also performed. To consolidate information and promote management an ecological conceptual model was built to identify potential problems for the nursery function played by these estuaries, identifying pressure agents, ecological impacts and endpoints for the anthropogenic sources quantified in the assessment. This will be important baseline information to safeguard these vital areas, articulating information and forecasting the potential efficacy of future management options.

  7. Is there a possibility of ranking benthic quality assessment indices to select the most responsive to different human pressures?

    Science.gov (United States)

    Borja, Ángel; Marín, Sandra L; Muxika, Iñigo; Pino, Loreto; Rodríguez, José G

    2015-08-15

    Although a plethora of benthic indices exist, there is no agreement on what index or indices should be used by environmental managers to establish benthic quality. The objective of this investigation was to rank 35 benthic quality assessment indices used in different countries to evaluate the impact produced by 15 different human pressures (including multipressure, aquaculture, sewage discharges, eutrophication, physical alteration, chemical pollution, climate change, etc.). The ranking was determined by taking into account the coverage area of biogeographical provinces, number of citations testing a pressure and number of citations with significant correlation with pressure. We analysed 363 references, of which 169 showed quantitative data. Over a potential total score of 100, the highest values were obtained by the following indices: (i) AZTI's Marine Biotic Index (AMBI), which scored 77, tested by using 14 pressures in 14 provinces from the Arctic to tropical seas; (ii) multivariate AMBI (M-AMBI), which scored 74, tested with 12 pressures in 13 provinces; (iii) Bentix (BENTIX), which scored 68, tested with nine pressures in six provinces; (iv) Benthic Quality Index (BQI), which scored 66, tested with five pressures in seven provinces; and (v) Benthic Opportunistic Polychaetes Amphipods (BOPA) index, which scored 62, tested with eight pressures in six provinces.

  8. The 2015 Canadian Hypertension Education Program recommendations for blood pressure measurement, diagnosis, assessment of risk, prevention, and treatment of hypertension.

    Science.gov (United States)

    Daskalopoulou, Stella S; Rabi, Doreen M; Zarnke, Kelly B; Dasgupta, Kaberi; Nerenberg, Kara; Cloutier, Lyne; Gelfer, Mark; Lamarre-Cliche, Maxime; Milot, Alain; Bolli, Peter; McKay, Donald W; Tremblay, Guy; McLean, Donna; Tobe, Sheldon W; Ruzicka, Marcel; Burns, Kevin D; Vallée, Michel; Ramesh Prasad, G V; Lebel, Marcel; Feldman, Ross D; Selby, Peter; Pipe, Andrew; Schiffrin, Ernesto L; McFarlane, Philip A; Oh, Paul; Hegele, Robert A; Khara, Milan; Wilson, Thomas W; Brian Penner, S; Burgess, Ellen; Herman, Robert J; Bacon, Simon L; Rabkin, Simon W; Gilbert, Richard E; Campbell, Tavis S; Grover, Steven; Honos, George; Lindsay, Patrice; Hill, Michael D; Coutts, Shelagh B; Gubitz, Gord; Campbell, Norman R C; Moe, Gordon W; Howlett, Jonathan G; Boulanger, Jean-Martin; Prebtani, Ally; Larochelle, Pierre; Leiter, Lawrence A; Jones, Charlotte; Ogilvie, Richard I; Woo, Vincent; Kaczorowski, Janusz; Trudeau, Luc; Petrella, Robert J; Hiremath, Swapnil; Stone, James A; Drouin, Denis; Lavoie, Kim L; Hamet, Pavel; Fodor, George; Grégoire, Jean C; Fournier, Anne; Lewanczuk, Richard; Dresser, George K; Sharma, Mukul; Reid, Debra; Benoit, Geneviève; Feber, Janusz; Harris, Kevin C; Poirier, Luc; Padwal, Raj S

    2015-05-01

    The Canadian Hypertension Education Program reviews the hypertension literature annually and provides detailed recommendations regarding hypertension diagnosis, assessment, prevention, and treatment. This report provides the updated evidence-based recommendations for 2015. This year, 4 new recommendations were added and 2 existing recommendations were modified. A revised algorithm for the diagnosis of hypertension is presented. Two major changes are proposed: (1) measurement using validated electronic (oscillometric) upper arm devices is preferred over auscultation for accurate office blood pressure measurement; (2) if the visit 1 mean blood pressure is increased but blood pressure measurements using ambulatory blood pressure monitoring (preferably) or home blood pressure monitoring should be performed before visit 2 to rule out white coat hypertension, for which pharmacologic treatment is not recommended. A standardized ambulatory blood pressure monitoring protocol and an update on automated office blood pressure are also presented. Several other recommendations on accurate measurement of blood pressure and criteria for diagnosis of hypertension have been reorganized. Two other new recommendations refer to smoking cessation: (1) tobacco use status should be updated regularly and advice to quit smoking should be provided; and (2) advice in combination with pharmacotherapy for smoking cessation should be offered to all smokers. The following recommendations were modified: (1) renal artery stenosis should be primarily managed medically; and (2) renal artery angioplasty and stenting could be considered for patients with renal artery stenosis and complicated, uncontrolled hypertension. The rationale for these recommendation changes is discussed.

  9. [Assessment at distance of a self-measurement of blood pressure education program: The PEA].

    Science.gov (United States)

    Atallah, A; Pham Hoang Minh, A; Billy-Brissac, R; Dinarque, C

    2015-06-01

    Current recommendations advocate self-measurement of blood pressure (SMBP) for the diagnosis and monitoring of high blood pressure (HBP). The "PEA" is an education program of the HTA GWAD network. Its mission is to train hypertensive patients with SMBP. The objective of this study is to evaluate between 6 months to 1 year after the efficiency of this program on the theoretical and practical knowledge of patients, as well as their behavior towards hypertension. Hundred and twenty patients were included in the study. In an interview, their knowledge was assessed using a questionnaire. The acquisition of the technique, reading and figures transcription, purchase of a SMBP device were also evaluated. The average questionnaire score was 5.7/13 (σ=2.7) before the educational session, 9.5/13 (σ=1.9) 1 week after the educational session. This improvement persisted over time with 8.9/13 (σ=2.9) correct answers 6 months to 1 year later. Exactly 73.3% (n=88/120) had a self-measurement device. Among them, 44.3% (n=39/88) practiced SMBP before medical consultations and 10% systematically did it before each medical consultation. A number of 84.2% (n=101/120) mastered the technique and 76.7% (n=92/120) of patients knew how to transcribe figures. Reading and understanding figures were acquired by 61.7% (n=74/120) of patients. A high level of education was correlated with a high level of practice. PEA is a sustainable solid and stable education program. However, the practice of SMBP is not yet systematic and remains to be encouraged in some patients. Given this situation, the network offers improvements in its program: highlighting of objectives, calendar reminder, "coaching" nurse.

  10. Echocardiographic Assessment of Pulmonary Artery Systolic Pressure and Outcomes in Ambulatory Heart Failure Patients

    Science.gov (United States)

    Kalogeropoulos, Andreas P.; Siwamogsatham, Sarawut; Hayek, Salim; Li, Song; Deka, Anjan; Marti, Catherine N.; Georgiopoulou, Vasiliki V.; Butler, Javed

    2014-01-01

    Background Pulmonary hypertension (PH) in patients with heart failure (HF) is associated with worse outcomes and is rapidly being recognized as a therapeutic target. To facilitate pragmatic research efforts, data regarding the prognostic importance of noninvasively assessed pulmonary artery systolic pressure (PASP) in stable ambulatory patients with HF are needed. Methods and Results We examined the association between echocardiographic PASP and outcomes in 417 outpatients with HF (age, 54±13 years; 60.7% men; 50.4% whites; 24.9% with preserved ejection fraction). Median PASP was 36 mm Hg (interquartile range [IQR]: 29, 46). After a median follow‐up of 2.6 years (IQR: 1.7, 3.9) there were 72 major events (57 deaths; 9 urgent heart transplants; and 6 ventricular assist device implantations) and 431 hospitalizations for HF. In models adjusting for clinical risk factors and therapy, a 10‐mm Hg higher PASP was associated with 37% higher risk (95% CI: 18, 59; P<0.001) for major events, and 11% higher risk (95% CI: 1, 23; P=0.039) for major events or HF hospitalization. The threshold that maximized the likelihood ratio for both endpoints was 48 mm Hg; those with PASP ≥48 mm Hg (N=84; 20.1%) had an adjusted hazard ratio of 3.33 (95% CI: 1.96, 5.65; P<0.001) for major events and 1.47 (95% CI: 1.02, 2.11; P=0.037) for major events or HF hospitalization. Reduced right ventricular systolic function had independent prognostic utility over PASP for adverse outcomes. Right atrial pressure and transtricuspid gradient both contributed to risk. Conclusions Elevated PASP, determined by echocardiography, identifies ambulatory patients with HF at increased risk for adverse events. PMID:24492947

  11. Ultrasound as a Noninvasive Method to Assess Changes of Intracranial Volume and Pressure During Simulated Microgravity

    Science.gov (United States)

    Murthy, G.; Yost, W. T.; Ballard, R. E.; Watenpaugh, D. E.; Kawai, Y.; Hargens, A. R.

    1994-01-01

    Headaches are commonly experienced by astronauts in microgravity and by subjects undergoing head-down tilt (simulated microgravity on Earth). Exposure to microgravity probably elevates blood pressure and flow in the head which may increase intracranial volume (ICV) and pressure (ICP) and in turn cause headache. Due to the slightly compliant nature of the cranial vault and the encasement of brain and its vasculature within this vault, any increase of ICV will increase ICP and slightly distend the cranium. Previous studies document perivascular edema and increased ICP in rhesus monkeys during head-down tilt. Elevated ICP has also been reported in humans during head-down tilt. ICP measurements in healthy humans are rare because of the invasiveness of currently-available measurement techniques. Therefore, we proposed a noninvasive ultrasound technique to assess changes of ICV and JCP. The ultrasound principle is based on compliance of the cranial vault. A 450 kHz ultrasound stimulus is transmitted through the cranium by a transducer every 7.5-10 msec. The ultrasound wave enters the brain tissue, reflects off the opposite side of the cranium and is received by the same transducer. The detected wave is compared for phase quadrature (90 deg.to transmitted wave). Because the electronic circuitry of the device maintains a 90 deg. phase (phi), any alterations in the detected wave caused by an increase of ICV and ICP will be reflected as a change in the wave frequency. Phase shift is directly proportional to path length of the wave, DELTA x, which is expressed as DELTA x = phi lambda/2 pi where lambda is wavelength. Elevated ICV and ICP expand the cranial vault and increase path length of the wave (a measure of intracranial distance). Increased path length equals reduced frequency of the detected wave. Reduced frequency is then related to elevated ICP. This technique has potential uses for ICP studies of astronauts in space and head trauma patients on Earth.

  12. The relationship between intracranial pressure and size of cerebral ventricles assessed by computed tomography.

    Science.gov (United States)

    Eide, P K

    2003-03-01

    This study explored whether assessment of the cerebral ventricular size (or changes in size) by cranial computed tomography (CT) is a reliable way to predict the intracranial pressure (ICP). A total of 224 cranial CT scans and continuous 24 hours ICP recordings in 184 patients were examined and compared. In these cases examinations were undertaken on the basis of suspected craniosynostosis, hydrocephalus or extracranial shunt failure. Simultaneous CT scanning and ICP monitoring was performed twice in 31 cases. Various measures of cerebral ventricular size were computed on the basis of CT, including Evan's index, third ventricular index, cella media index and ventricular score. Various measures of ICP were computed by means of the software Sensometrics Pressure Analyser, including computation of mean ICP, numbers of ICP elevations (20-30 mmHg lasting either 0.5, 1, 5 or 10 minutes), and numbers of ICP depressions (-5 or -10 mmHg lasting either 0.5, 1, 5 or 10 minutes) during a standardized recording time of 10 hours. The relationships between the various measures of ventricular size and the various measures of ICP were explored. There was a weak and non-significant relationship between the various measures of ventricular size and the measures of ICP in the 184 cases. There was a weak relationship between changes in size of cerebral ventricles and changes in ICP in the 31 cases examined twice. The present results suggest that actual size or changes in size of the cerebral ventricles were no reliable predictors of ICP or changes in ICP, suggesting that great caution should be exercised when predicting ICP on the basis of the size of the cerebral ventricles on cranial CT scanning.

  13. A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas: The PERSEUS experience

    DEFF Research Database (Denmark)

    Crise, A.; Kaberi, H.; Ruiz, José Luis Martinez;

    2015-01-01

    PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD......). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also...

  14. Prediction of pressure ulcer development in hospitalized patients : a tool for risk assessment.

    NARCIS (Netherlands)

    Schoonhoven, L.; Grobbee, D.E.; Donders, A.R.T.; Algra, A.; Grypdonck, M.H.; Bousema, M.T.; Schrijvers, A.J.P.; Buskens, E.

    2006-01-01

    OBJECTIVES: To identify independent predictors for development of pressure ulcers in hospitalized patients and to develop a simple prediction rule for pressure ulcer development. DESIGN: The Prevention and Pressure Ulcer Risk Score Evaluation (prePURSE) study is a prospective cohort study in which p

  15. Prediction of pressure ulcer development in hospitalized patients : a tool for risk assessment

    NARCIS (Netherlands)

    Schoonhoven, L.; Grobbee, D.E.; Donders, A.R.T.; Algra, A.; Grypdonck, M.H.; Bousema, M.T.; Schrijvers, A.J.P.; Buskens, E.

    2006-01-01

    Objectives: To identify independent predictors for development of pressure ulcers in hospitalized patients and to develop a simple prediction rule for pressure ulcer development. Design: The Prevention and Pressure Ulcer Risk Score Evaluation (prePURSE) study is a prospective cohort study in which p

  16. Evaluation of the mold-filling ability of alloy melt in squeeze casting

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mold-filling ability of alloy melt in squeeze casting process was evaluated by means of the maximum length of Archimedes spiral line. A theoretical evaluating model to predict the maximum filling length was built based on the flowing theory of the incompressible viscous fluid. It was proved by experiments and calculations that the mold-filling pressure and velocity are prominent influencing factors on the mold-filling ability of alloy melt. The mold-filling ability increases with the increase of the mold-filling pressure and the decrease of the proper mold-filling velocity. Moreover, the pouring temperature relatively has less effect on the mold-filling ability under the experimental conditions. The maximum deviation of theoretical calculating values with experimental results is less than 15%. The model can quantitatively estimate the effect of every factor on the mold-filling ability.

  17. Country-wide assessment of estuary health: An approach for integrating pressures and ecosystem response in a data limited environment

    Science.gov (United States)

    Van Niekerk, L.; Adams, J. B.; Bate, G. C.; Forbes, A. T.; Forbes, N. T.; Huizinga, P.; Lamberth, S. J.; MacKay, C. F.; Petersen, C.; Taljaard, S.; Weerts, S. P.; Whitfield, A. K.; Wooldridge, T. H.

    2013-09-01

    Population and development pressures increase the need for proactive strategic management on a regional or country-wide scale - reactively protecting ecosystems on an estuary-by-estuary basis against multiple pressures is 'resource hungry' and not feasible. Proactive management requires a strategic assessment of health so that the most suitable return on investment can be made. A country-wide assessment of the nearly 300 functional South African estuaries examined both key pressures (freshwater inflow modification, water quality, artificial breaching of temporarily open/closed systems, habitat modification and exploitation of living resources) and health state. The method used to assess the type and level of the different pressures, as well as the ecological health status of a large number of estuaries in a data limited environment is described in this paper. Key pressures and the ecological condition of estuaries on a national scale are summarised. The template may also be used to provide guidance to coastal researchers attempting to inform management in other developing countries. The assessment was primarily aimed at decision makers both inside and outside the biodiversity sector. A key starting point was to delineate spatially the estuary functional zone (area) for every system. In addition, available data on pressures impacting estuaries on a national scale were collated. A desktop national health assessment, based on an Estuarine Health Index developed for South African ecological water requirement studies, was then applied systematically. National experts, all familiar with the index evaluated the estuaries in their region. Individual estuarine health assessment scores were then translated into health categories that reflect the overall status of South Africa's estuaries. The results showed that estuaries in the warm-temperate biogeographical zone are healthier than those in the cool-temperate and subtropical zones, largely reflecting the country

  18. Filling in biodiversity threat gaps

    DEFF Research Database (Denmark)

    Joppa, L. N.; O'Connor, Brian; Visconti, Piero

    2016-01-01

    increase to 10,000 times the background rate should species threatened with extinction succumb to pressures they face (4). Reversing these trends is a focus of the Convention on Biological Diversity's 2020 Strategic Plan for Biodiversity and its 20 Aichi Targets and is explicitly incorporated...... into the United Nations' 2030 Agenda for Sustainable Development and its 17 Sustainable Development Goals (SDGs). We identify major gaps in data available for assessing global biodiversity threats and suggest mechanisms for closing them....

  19. Skin perfusion pressure measured with a photo sensor in an air-filled plastic balloon: validity and reproducibility on the lower leg in normal subjects and patients suspected of obliterative arterial disease

    DEFF Research Database (Denmark)

    Nielsen, Steen Levin; Nielsen, Anne Lerberg; Vind, Susanne Haase

    2011-01-01

    An inflatable small plastic bag including a photo sensor was constructed for measurement of skin perfusion pressure avoiding the rim of the photo sensor over bony and tendineous surfaces of the tibia below the knee, at the ankle, and on the dorsal forefoot. Compression was obtained using a conical...... pressure device thus had acceptable validity and reproducibility for estimation of the skin perfusion pressure and can be used on bony and tendineous sites on the lower limb in regions where critical wound healing is frequent, e.g. ankle and forefoot....

  20. Stem Hydraulic Conductivity depends on the Pressure at Which It Is Measured and How This Dependence Can Be Used to Assess the Tempo of Bubble Pressurization in Recently Cavitated Vessels1[OPEN

    Science.gov (United States)

    Liu, Jinyu; Tyree, Melvin T.

    2015-01-01

    Cavitation of water in xylem vessels followed by embolism formation has been authenticated for more than 40 years. Embolism formation involves the gradual buildup of bubble pressure (air) to atmospheric pressure as demanded by Henry’s law of equilibrium between gaseous and liquid phases. However, the tempo of pressure increase has not been quantified. In this report, we show that the rate of pressurization of embolized vessels is controlled by both fast and slow kinetics, where both tempos are controlled by diffusion but over different spatial scales. The fast tempo involves a localized diffusion from endogenous sources: over a distance of about 0.05 mm from water-filled wood to the nearest embolized vessels; this process, in theory, should take 17 h, with complete equilibrium requiring 1 to 2 d. The implications of these timescales for the standard methods of measuring percentage loss of hydraulic conductivity are discussed in theory and deserve more research in future. PMID:26468516

  1. Invasively Measured Aortic Systolic Blood Pressure and Office Systolic Blood Pressure in Cardiovascular Risk Assessment: A Prospective Cohort Study

    DEFF Research Database (Denmark)

    Laugesen, Esben; Knudsen, Søren T; Hansen, Klavs W

    2016-01-01

    myocardial infarction, stroke, and death. Discrimination and reclassification were assessed using Harrell's C and the Continuous Net Reclassification Index. Data were analyzed with and without stratification by diabetes mellitus status. During a median follow-up period of 3.7 years (range: 0.1-10.8 years......), 422 strokes, 511 myocardial infarctions, and 1530 deaths occurred. Both office and aortic systolic BP were associated with stroke in patients with diabetes mellitus (hazard ratio per 10 mm Hg, 1.18 [95% confidence interval, 1.07-1.30] and 1.14 [95% confidence interval, 1.05-1.24], respectively...

  2. Tension-filled Governance?

    DEFF Research Database (Denmark)

    Celik, Tim Holst

    Since the crisis-engrossed 1970s, and especially the 1990s, ‘governance’ has become a dominant concern and concept; notably, within particularly political science, a certain diagnosis explicitly or implicitly focused on a shift ‘from government to governance’ has become increasingly popular....... This study examines the governance phenomenon of the post-1970/1990s period from a state-situated and historically informed perspective. Specifically, taking initial analytical departure in an approach of the early 1970s associated with James O’Connor, Jürgen Habermas and Claus Offe focused...... on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...

  3. Preparing for faster filling

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Following the programmed technical stop last week, operators focussed on preparing the machine for faster filling, which includes multibunch injection and a faster pre-cycle phase.   The LHC1 screen shot during the first multibunch injection operation. The LHC operational schedule incorporates a technical stop for preventive maintenance roughly every six weeks of stable operation, during which several interventions on the various machines are carried out. Last week these included the replacement of a faulty magnet in the SPS pre-accelerator, which required the subsequent re-setting of the system of particle extraction and transfer to the LHC. At the end of last week, all the machines were handed back for operation and work could start on accommodating all the changes made into the complex systems in order for normal operation to be resumed. These ‘recovery’ operations continued through the weekend and into this week. At the beginning of this week, operators succeeded in pro...

  4. Reactor Pressure Vessel Integrity Assessments with the Grizzly Aging Simulation Code

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Benjamin; Backman, Marie; Hoffman, William; Chakraborty, Pritam

    2015-08-01

    Grizzly is a simulation tool being developed at Idaho National Laboratory (INL) as part of the US Department of Energy’s Light Water Reactor Sustainability program to provide improved safety assessments of systems, components, and structures in nuclear power plants subjected to age-related degradation. Its goal is to provide an improved scientific basis for decisions surrounding license renewal, which would permit operation of commercial nuclear power plants beyond 60 years. Grizzly is based on INL’s MOOSE framework, which enables multiphysics simulations in a parallel computing environment. It will address a wide variety of aging issues in nuclear power plant systems, components, and structures, modelling both the aging processes and the ability of age-degraded components to perform safely. The reactor pressure vessel (RPV) was chosen as the initial application for Grizzly. Grizzly solves tightly coupled equations of heat conduction and solid mechanics to simulate the global response of the RPV to accident conditions, and uses submodels to represent regions with pre-existing flaws. Domain integrals are used to calculate stress intensity factors on those flaws. A physically based empirical model is used to evaluate material embrittlement, and is used to evaluate whether crack growth would occur. Grizzly can represent the RPV in 2D or 3D, allowing it to evaluate effects that require higher dimensionality models to capture. Work is underway to use lower length scale models of material evolution to inform engineering models of embrittlement. This paper demonstrates an application of Grizzly to RPV failure assessment, and summarizes on-going work.

  5. Noninvasive Techniques for Intracranial Pressure Assessment: A Review from Aerospace Medicine Perspective

    Science.gov (United States)

    Hamilton, Douglas R.; Sargsyan, Ashot E.; Fogarty, Jennifer; Ebert, Douglas J. W.; Polk, J. D.

    2010-01-01

    Microgravity-induced changes in fluid distribution and other physiological factors due to space flight have been implicated as the cause of increased intracranial pressure (ICP) in a number of space crewmembers. The modest levels of ICP elevation and absence of severe symptoms in this group do not warrant invasive diagnostic interventions. However, the long-term trends and residual or consequential changes secondary to the observed ICP elevation in this group are not yet known. Therefore, close attention is needed to evaluate the potential techniques of noninvasively assessing ICP, including those feasible for in-flight use. Of particular interest is continuity between ground and in-flight testing, whereby data from the same or different techniques allow reasonably dependable estimation of ICP trends and responses. Methods: A thorough review of current literature, analysis of NASA data, and interviews with subject matter experts were conducted to construct a presentation that reflects the state of the art for noninvasive ICP measurement and monitoring. Results: Multiple imaging and non-imaging modalities are available to assess ICP in terrestrial clinical and experimental environments. Imaging alternatives include magnetic resonance imaging (MRI) and high-resolution sonography. Non-imaging techniques include transcranial Doppler, certain audiological methods, and venous ophthalmodynamometry, among others. Special functional techniques have been proposed recently that allow the use of advanced MRI methods to calculate ICP in addition to the acquisition of high-resolution images. Our data include many of these applications, with several cases of correlation with lumbar puncture, the invasive "gold standard" measurement of ICP.

  6. Noninvasive assessment of cardiac output from arterial pressure profiles during exercise.

    Science.gov (United States)

    Antonutto, G; Girardis, M; Tuniz, D; di Prampero, P E

    1995-01-01

    The stroke volume of the left ventricle (SV) was assessed in nine young men (mean age 22.2, ranging from 20 to 25 years) during cycle ergometer upright exercise at exercise intensities from 60 to 150 W (about 20% to 80% of individual maximal aerobic power). The SV was calculated from noninvasive tracings of the arterial blood pressure, determined from photoplethysmograph records and compared to the SV determined simultaneously by pulsed Doppler echocardiography (PDE). Given the relationship SV = As.Z-1 in which A(s) is the area underneath the systolic pressure profile (in millimetres of mercury and second), and Z (in millimetres of mercury and second per millilitre) is the apparent hydraulic impedance of the circulatory system, a prerequisite for the assessment of SV from the photoplethysmograph tracings is a knowledge of Z. The experimental value of Z (hereafter defined Z*) was calculated by dividing A(s) (from the finger photoplethysmograph) by SV as obtained by PDE. When the whole group of subjects was considered, Z* was not greatly affected by the exercise intensity: it amounted to 0.089 (SD 0.028; n = 36). The Z was also estimated independently of any parameter other than heart rate (HR), mean (MAP) and pulse (PP) arterial blood pressure obtained from the photoplethysmograph. A computerized statistical method allowed us to interpolate the experimental values of Z*, HR, PP and MAP by the equation Zm = a.(b + c.HR + d.PP + e.MAP)-1, thus obtaining the coefficients a to e. The mean percentage error between Zm (calculated from the coefficients obtained and Z* was 21.8 (SD 14.3)%. However, it was observed that, in a given subject, Z* was significantly affected by the exercise intensity. Therefore, to improve the estimate of Z a second algorithm was developed to update the experimental value of Z determined initially at rest (Zin). This updated value (Zcor) of Z was calculated as Zcor = Zin. [(f/(i + g.(HR/HRin) + h.(PP/PPin) + 1.(MAP/MAPin)], where HRin, PPin

  7. Quality of root fillings performed with two root filling techniques. An in vitro study using micro-CT

    DEFF Research Database (Denmark)

    Moeller, L.; Wenzel, A.; Wegge-Larsen, A. M.

    2013-01-01

    Abstract Objective. The aim of this study was to compare the presence of voids in root fillings performed in oval and ribbon-shaped canals with two root filling techniques, lateral compaction technique (LCT) or hybrid technique (HT), a combination of a gutta-percha masterpoint and thermoplastic...... gutta-percha. Furthermore, the obturation time for the two techniques was evaluated. Materials and methods. Sixty-seven roots with oval and ribbon-shaped canals were prepared using Profile Ni-Ti rotary files. After preparation, the roots were randomly allocated to two groups according to root filling...... technique. All roots were filled with AH plus and gutta-percha. Group 1 was filled using LCT (n = 34) and group 2 was filled using HT (n = 33). The obturation time was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fillings were assessed using cross...

  8. Risk Assessment Tool for Pressure Ulcer Development in Indian Surgical Wards.

    Science.gov (United States)

    Kumari, Sushma; Sharma, Deborshi; Rana, Anshika; Pathak, Reetesh; Lal, Romesh; Kumar, Ajay; Biswal, U C

    2015-06-01

    The aims of this paper were to compare the predictive validity of three pressure ulcer (PU) risk scales-the Norton scale, the Braden scale, and the Waterlow scale-and to choose the most appropriate calculator for predicting PU risk in surgical wards of India. This is an observational prospective cohort study in a tertiary educational hospital in New Delhi among 100 surgical ward patients from April to July 2011. The main outcomes measured included sensitivity, specificity, positive predictive value (PVP) and negative predictive value (PVN), and the area under the curve of the receiver operating characteristic (ROC) curve of the three PU risk assessment scales. Based on the cutoff points found most appropriate in this study, the sensitivity, specificity, PVP, and PVN were as follows: the Norton scale (cutoff, 16) had the values of 95.6, 93.5, 44.8, and 98.6, respectively; the Braden scale (cutoff, 17) had values of 100, 89.6, 42.5, and 100, respectively; and the Waterlow scale (cutoff, 11) had 91.3, 84.4, 38.8, and 97, respectively. According to the ROC curve, the Norton scale is the most appropriate tool. Factors such as physical condition, activity, mobility, body mass index (BMI), nutrition, friction, and shear are extremely significant in determining risk of PU development (p nutrition, friction, and shear are the most significant factors in Indian surgical ward settings with necessity for future comparison with established scales.

  9. Country-wide assessment of estuary health: An approach for integrating pressures and ecosystem response in a data limited environment

    CSIR Research Space (South Africa)

    Van Niekerk, L

    2013-09-01

    Full Text Available Estuarine, coastal and shelf science 130 (2013) 239e251 COUNTRY-WIDE ASSESSMENT OF ESTUARY HEALTH: AN APPROACH FOR INTEGRATING PRESSURES AND ECOSYSTEM RESPONSE IN A DATA LIMITED ENVIRONMENT L. Van Niekerk a,b,*, J.B. Adams b, G.C. Bate b, A...

  10. Monitoring healing of pressure ulcers : a review of assessment instruments for use in the spinal cord unit

    NARCIS (Netherlands)

    van Lis, M. S.; van Asbeck, F. W. A.; Post, M. W. M.

    2010-01-01

    Study design: Review. Objectives: To identify the pressure ulcer healing assessment instrument that is the best choice for use in spinal cord injury rehabilitation. Methods: Articles were retrieved from PubMed. Inclusion criteria were written in English, published up to December 2008 and describing

  11. Assessing the effectiveness of low-pressure ultraviolet light for inactivating Mycobacterium avium complex (MAC) micro-organisms

    Science.gov (United States)

    Aims: To assess low-pressure ultraviolet light (LP-UV) inactivation kinetics of Mycobacterium avium complex (MAC) strains in a water matrix using collimated beam apparatus. Methods and Results: Strains of M. avium (n = 3) and Mycobacterium intracellulare (n = 2) were exposed t...

  12. Assessing the effectiveness of low-pressure ultraviolet light for inactivating Mycobacterium avium complex (MAC) micro-organisms

    Science.gov (United States)

    Aims: To assess low-pressure ultraviolet light (LP-UV) inactivation kinetics of Mycobacterium avium complex (MAC) strains in a water matrix using collimated beam apparatus. Methods and Results: Strains of M. avium (n = 3) and Mycobacterium intracellulare (n = 2) were exposed t...

  13. Assessment of Intraocular and Systemic Vasculature Pressure Parameters in Simulated Microgravity with Thigh Cuff Countermeasure

    Science.gov (United States)

    Huang, Alex S.; Balasubramanian, Siva; Tepelus, Tudor; Sadda, Jaya; Sadda, Srinivas; Stenger, Michael B.; Lee, Stuart M. C.; Laurie, Steve S.; Liu, John; Macias, Brandon R.

    2017-01-01

    Changes in vision have been well documented among astronauts during and after long-duration space flight. One hypothesis is that the space flight induced headward fluid alters posterior ocular pressure and volume and may contribute to visual acuity decrements. Therefore, we evaluated venoconstrictive thigh cuffs as a potential countermeasure to the headward fluid shift-induced effects on intraocular pressure (IOP) and cephalic vascular pressure and volumes.

  14. Use of ROV for assessing marine litter on the seafloor of Saronikos Gulf (Greece): a way to fill data gaps and deliver environmental education.

    Science.gov (United States)

    Ioakeimidis, C; Papatheodorou, G; Fermeli, G; Streftaris, N; Papathanassiou, E

    2015-01-01

    A visual census of marine litter on the seafloor of the Saronikos Gulf (Greece) is presented in the current work. The abundance and qualitative composition of benthic marine litter were investigated in two selected locations of the Saronikos Gulf with a Remote Operated Vehicle, where other sampling strategies couldn't be implemented. The assessment of marine litter was combined with environmental education within the PERSEUS (FP7) Research Project, in a novel 2-day research cruise where schoolchildren actively participated. Two transects of total length 2.36 km were carried out. A relevant marine litter protocol was developed where marine litter was categorized into six different categories according to their material type and where possible, the source of the items was identified. Plastics (55 %) and metals (36 %) had the biggest share among the recorded marine litter items. Marine litter proved to be an ideal theme in order to enhance the environmental awareness of schoolchildren.

  15. Assessment of coercive and noncoercive pressures to enter drug abuse treatment.

    Science.gov (United States)

    Marlowe, D B; Kirby, K C; Bonieskie, L M; Glass, D J; Dodds, L D; Husband, S D; Platt, J J; Festinger, D S

    1996-10-01

    This paper reports preliminary data derived from a standardized interview scoring procedure for detecting and characterizing coercive and noncoercive pressures to enter substance abuse treatment. Coercive and noncoercive pressures stemming from multiple psychosocial domains are operationalized through recourse to established behavioral principles. Inter-rater reliability for the scoring procedure was exceptional over numerous rater trials. Substantive analyses indicate that, among clients in outpatient cocaine treatment, 'coercion' is operative in multiple psychosocial domains, and that subjects perceive legal pressures as exerting substantially less influence over their decisions to enter treatment than informal psychosocial pressures. Implications for drug treatment planning, legal and ethical issues, and directions for future research are proposed.

  16. 薄壁铝合金压铸充型过程中铸件与铸型界面的换热行为%Heat transfer behaviors between metal and die during filling process of thin-wall aluminum alloy under high pressure die casting conditions

    Institute of Scientific and Technical Information of China (English)

    朱必武; 李落星; 刘筱; 张立强; 徐戎; 卜晓兵

    2013-01-01

    The thin-wall AlSi10MnMg aluminum alloy samples were prepared by high pressure die casting. The motion laws of press-shoot ram were recorded by a high speed camera system and the heat transfer coefficients between the casting and mold were calculated by the energy conservation equation. Therefore, the effects of different heat transfer coefficients on the simulated filling results were discussed. The results show that the filling fluidity length increases with the pouring temperature increasing;when the filling process is above the liquidus, the filling time and the heat transfer coefficient increase with the pouring temperature increasing. However, when the filling process is below the liquidus, the changes of the filling time and the heat transfer coefficient are insignificant. The simulations using the heat transfer coefficient which is calculated by the energy conservation equation are well consistent with the experimental results.%采用压铸制备薄壁AlSi10MnMg铝合金铸件,用高速摄像技术记录分析压铸压射冲头的运动规律,并通过热平衡方程求解充型过程中铸件熔体和铸型之间的换热系数,最后通过数值模拟的方法讨论采用不同换热系数对充型仿真结果的影响。结果表明:充型流动长度随浇注温度的升高而增长;当充型处于液相线温度之上时,充型时间、换热系数随浇注温度的升高而增长;当充型至温度处于液相线温度以下时,充型时间和换热系数变化都很小。模拟仿真结果显示,采用基于热平衡方程求得的换热系数的计算模拟仿真结果与实验结果较一致。

  17. Knowledge gaps in relation to radionuclide levels and transfer to wild plants and animals, in the context of environmental impact assessments, and a strategy to fill them

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.E. (ed.); Gjelsvik, R. (Norwegian Radiation Protection Authority (Norway)); Saxen, R.; Mattila, J. (STUK - Radiation and Nuclear Safety Authority (Finland))

    2009-01-15

    International activities with regards the development of methods for assessing impacts on the environment from ionising radiation have been substantial in recent years. In developing these methods, there are requirements (i) to determine the transfer of radionuclides within ecosystems and (ii) to determine background dose-rates arising from the presence of naturally occurring radionuclides, in a satisfactory manner. It has quickly become evident that fulfilling these 2 requirements is not entirely straightforward reflecting a lack of data in many cases. This report specifies exactly where these data-gaps lie through analyses of data generated from the most recent studies conducted internationally on this topic. It is evident that information is limited for numerous radionuclides from U-238 and Th-232 decay series and notably, in view of its importance as a contributor to dose-rates in plants and animals, Po-210. The simple way to rectify these data deficiencies is to organise target field campaigns focusing on particular species and radionuclides where information is lacking. To this end, field sampling has been conducted in a semi-natural mountain ecosystem in Norway and freshwater aquatic systems in Finland. It is envisaged that the data derived from the studies briefly described in this report will provide fundamental information for our understanding of the behaviour and fate of natural decay series radionuclides in terrestrial and aquatic systems and provide the basis for more robust way. (au)

  18. Noninvasively assessed pulsatility of ascending aortic pressure waveform is associated with the presence of coronary artery narrowing.

    Science.gov (United States)

    Wykretowicz, Andrzej; Metzler, Lidia; Milewska, Agata; Balinski, Marek; Rutkowska, Agnieszka; Adamska, Karolina; Krauze, Tomasz; Guzik, Przemysław; Dziarmaga, Mieczysław; Wysocki, Henryk

    2008-01-01

    Several hemodynamic indices, measured invasively in the ascending aorta during routine angiography, are related to the presence and severity of coronary atherosclerosis. Radial artery tonometry, when combined with a validated transfer function, offers the possibility of noninvasive assessment of central arterial pressure. We aim to evaluate the association between noninvasive indices of aortic or radial pressure waveforms and the presence of a significant coronary stenosis. Patients who underwent elective coronary angiography were studied (110 men, 91 women, mean age 53 +/- 0.9 years). Noninvasive measurement of their central hemodynamics was performed by analysis of the aortic pressure waveform derived from the radial artery. An increase in aortic fractional pulse pressure was associated with coronary artery narrowing or previous myocardial infarction. After multivariate adjustment, the odds ratio and confidence intervals (CI) of having a significant coronary aortic stenosis was 1.72 (95% CI, 1.1-2.7) and of previous myocardial infarction 1.6 (95% CI, 1.1-2.2). An increase in noninvasively assessed aortic fractional pulse pressure, but not of the peripheral index is significantly associated with the presence of coronary artery disease.

  19. Uncertainties in risk assessment of hydrogen discharges from pressurized storage vessels at low temperatures

    DEFF Research Database (Denmark)

    Markert, Frank; Melideo, D.; Baraldi, D.

    2013-01-01

    20K) e.g. the cryogenic compressed gas storage covers pressures up to 35 MPa and temperatures between 33K and 338 K. Accurate calculations of high pressure releases require real gas EOS. This paper compares a number of EOS to predict hydrogen properties typical in different storage types. The vessel...

  20. Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani, Effat; Mokhtari-Dizaji, Manijhe [Dept. of Medical Physics, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Fatouraee, Nasser [Dept. of Medical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Saben, Hazhir [Dept. Radiology, Imaging Center of Imam Khomaini Hospital, Tehran Medical Sciences University, Tehran (Iran, Islamic Republic of)

    2017-04-15

    The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg. The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes.

  1. Environmental assessment of Ultra-High Pressure Homogenisation for milk and fresh cheese production

    DEFF Research Database (Denmark)

    Valsasina, Lucia; Pizzol, Massimo; Smetana, Sergiy

    2015-01-01

    This study analyses the application of Ultra High Pressure Homogenisation (UHPH), an innovative technology for food sterilisation that relies on pressure up to 400MPa, for the treatment of cow milk. The technology is forseen to provide equal or higher quality products compared to Ultra High...

  2. Fifteen years experience with finger arterial pressure monitoring : Assessment of the technology

    NARCIS (Netherlands)

    Imholz, B.P.M.; Wieling, W.; Montfrans, G.A. van; Wesseling, K.H.

    1998-01-01

    We review the Finapres technology, embodied in several TNO-prototypes and in the Ohmeda 2300 and 2300e Finapres NIBP. Finapres is an acronym for FINger Arterial PRESsure, the device delivers a continuous finger arterial pressure waveform. Many papers report on the accuracy of the device in compariso

  3. Pressure/cross-sectional area probe in the assessment of urethral closure function. Reproducibility of measurement

    DEFF Research Database (Denmark)

    Lose, G; Schroeder, T

    1990-01-01

    -pressure zone and distally in the urethra. The in vitro study showed that cross sectional areas of 13-79 mm2 were determined with a SD of 1.4 mm2. In vivo measurements revealed that the urethral parameters: elastance, hysteresis, pressure and power of contraction during coughing and squeezing were fairly...

  4. Fifteen years experience with finger arterial pressure monitoring : Assessment of the technology

    NARCIS (Netherlands)

    Imholz, B.P.M.; Wieling, W.; Montfrans, G.A. van; Wesseling, K.H.

    1998-01-01

    We review the Finapres technology, embodied in several TNO-prototypes and in the Ohmeda 2300 and 2300e Finapres NIBP. Finapres is an acronym for FINger Arterial PRESsure, the device delivers a continuous finger arterial pressure waveform. Many papers report on the accuracy of the device in

  5. Risk assessment study of the pressure ulcers in intensive care unit patients.

    Science.gov (United States)

    Terekeci, Hakan; Kucukardali, Yasar; Top, Cihan; Onem, Yalçin; Celik, Serkan; Oktenli, Cağatay

    2009-07-01

    In this research, we studied the incidence of pressure ulcer and risk factors and screening of the patients for pressure ulcers at intensive care unit on the first day of admission in 142 patients. All patients were evaluated according to National Pressure Ulcer Advisory Panel during the ICU period strictly. Pressure ulcer risk evaluation was performed according to Norton Scale. Nutritional state was evaluated according to nutritional risk screening 2002. Age, hospitalization period, mean arterial pressure, pressure ulcer degree, hemoglobin and albumin levels, body mass index, APACHE-II scores and comorbidities were evaluated. In the following parameters, first value represents PU (+) cases, and second value represents PU (-) cases. On the admittance: 14 (9.8%) patients had PU (prevalence). NRS-2002: 5.4+/-1.9 and 4.3+/-2.1 (p0.05). Mean pressure ulcer degree was 2.15. On the discharge: first values represent new developed PU (+) patients and second values represent PU (-) cases. 25 (17.6%) patients had PU. Incidence was 7.8%. NRS-2002: 6.4 and 3.6 (p0.05). Two or more co morbidity, neurophyschiatric disorders, infections and medications were more prevalent in PU (+) group (pmalnutrition and hypoalbuminemia were significant in patients with PU; however, BMI and hemoglobin were not significant. The studies focusing on the relation between the effect of optimization of these parameters from the first day of admittance and pressure ulcer are required.

  6. Physiological impact of CTO recanalization assessed by coronary pressure measurement: a case report.

    Science.gov (United States)

    Matsuo, Hitoshi; Kawase, Yoshiaki

    2013-10-01

    In this case report, physiological changes of myocardial perfusion in the collateral recipient right coronary artery (RCA) and the collateral donor left anterior descending artery (LAD) with an intermediate lesion were assessed using intracoronary pressure measurement, before and after revascularization of chronic total occlusion (CTO). A 44-year-old male was referred for a catheter examination due to silent myocardial ischemia. An invasive coronary angiogram revealed diffuse narrowing of the RCA with focal occlusive segments in addition to intermediate stenosis in the LAD. A well developed collateral channel from the LAD to the RCA was also confirmed. Fractional flow reserve (FFRmyo) of the LAD before opening the RCA was 0.81. After successful revascularization of the RCA, FFRmyo of the LAD and the RCA were measured with and without an RCA balloon occlusion. Because collateral fractional flow reserve (FFRcoll) of the RCA could be regarded as FFRmyo before revascularization, FFRmyo of the RCA increased from 0.67 to 0.90, meaning a 23% increase of maximum flow by intervention. Interestingly, improvement of FFRmyo of the LAD from 0.81 to 0.93 was also observed, which means a 12% increase of maximum flow. Coronary steal in the LAD was reconfirmed by dramatic worsening of FFRmyo from 0.93 to 0.77 by an RCA balloon occlusion. This phenomenon may be explained by an immediate recruitment of collateral channels. This case clearly demonstrated that CTO opening improves perfusion in not only myocardium supplied by the CTO vessel, but also in that which is supplied by a contralateral collateral donor artery. Copyright © 2013 Wiley Periodicals, Inc.

  7. Intragastric pressure during food intake: a physiological and minimally invasive method to assess gastric accommodation.

    Science.gov (United States)

    Janssen, P; Verschueren, S; Ly, H Giao; Vos, R; Van Oudenhove, L; Tack, J

    2011-04-01

    The stomach relaxes upon food intake and thereby provides a reservoir while keeping the intragastric pressure (IGP) low. We set out to determine whether we could use IGP as a measurement for stomach accommodation during food intake. In fasted healthy volunteers (n = 7-17) a manometer and an infusion catheter were positioned in the proximal stomach. After a stabilization period a nutrient drink was intragastrically infused at 15, 30 and 60 mL min(-1). To investigate the effect of impaired accommodation the effect of N(G)-monomethyl-L-arginine (L-NMMA) was examined. The volunteers scored satiation until maximum, when the experiment ended. The IGP was presented as a change from baseline (mean ± SEM) and compared with repeated measures anova. Independent on the ingestion speed, the IGP decreased initially and gradually increased thereafter. Volunteers scored maximal satiation after 699 ± 62, 809 ± 90 and 997 ± 120 mL nutrient drink infused (15, 30 and 60 mL min(-1) respectively; P IGP decrease was 3.4 ± 0.5 mmHg after 205 ± 28 mL, 5.1 ± 0.7 mmHg after 212 ± 46 mL, and 5.2 ± 0.7 mmHg after 296 ± 28 mL infused volume [15, 30 and 60 mL min(-1) respectively; not significant (ns)]. Post hoc analysis showed significant correlations between IGP and satiation score increase. During L-NMMA infusion IGP was significantly increased while subjects drank significantly less (816 ± 91 vs 1032 ± 71 mL; P IGP increase and satiation score increase did not differ after L-NMMA treatment. The IGP during nutrient drink ingestion provides a minimally invasive alternative to the barostat for the assessment of gastric accommodation. These findings furthermore indicate that IGP is a major determinant of satiation. © 2011 Blackwell Publishing Ltd.

  8. Assessment of radiochemical purity of [{sup 18}F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z., E-mail: radiofarmacoscdtn@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

    2011-07-01

    The quality control of [{sup 18}F]fludeoxyglucose ({sup 18}FDG) has received attention due to its increasing clinical use. Although the quality requirements of {sup 18}FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of {sup 18}FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. {sup 18}FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of {sup 18}FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of {sup 18}FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of {sup 18}FDG, considering operational conditions of our laboratory. (author)

  9. Controlling and assessing pressure conditions during treatment of tar sands formations

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Etuan; Beer, Gary Lee

    2015-11-10

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the tar sands formation from a plurality of heaters located in the formation. Heat is allowed to transfer from the heaters to at least a portion of the formation. A pressure in the portion of the formation is controlled such that the pressure remains below a fracture pressure of the formation overburden while allowing the portion of the formation to heat to a selected average temperature of at least about 280.degree. C. and at most about 300.degree. C. The pressure in the portion of the formation is reduced to a selected pressure after the portion of the formation reaches the selected average temperature.

  10. The Intragastric Pressure Measurement: A Novel Method to Assess Gastric Accommodation in Functional Dyspepsia Children.

    Science.gov (United States)

    Carbone, Florencia; Tack, Jan; Hoffman, Ilse

    2017-06-01

    Impaired gastric accommodation (GA) is proposed as a main pathophysiological mechanism for functional dyspepsia (FD). At present, the gastric barostat is the criterion standard to measure GA. Hence, this procedure is invasive and it may alter gastric physiology. Recently, we proposed the measurement of intragastric pressure (IGP) by means of high-resolution manometry during nutrient intake as a potential alternative for assessing GA in adults. Our aim was first to study the feasibility of the IGP measurement with nutrient tolerance in children with FD and second to compare these results with young healthy adults. A high-resolution manometry probe and a feeding tube were positioned in the proximal stomach. The IGP was measured before and during intragastric infusion of a nutrient drink (ND, 300 kcal, 60 mL/min). Subjects were asked to score their satiation and epigastric symptoms. The test ended when the subjects scored maximal satiation. A total of 15 healthy volunteers (HVs, 21.7 ± 4.7 years, 21.1 ± 0.3 kg/m) and 17 patients with FD (14.4 ± 0.7 years, 19.6 ± 0.7 kg/m) participated. Patients with FD experienced mainly from postprandial fullness (86%), epigastric pain (71%), and bloating (62%). In both groups, intragastric infusion of ND induced a drop in IGP (area above the IGP curve FD: -15.5 ± 3.5 mmHg vs HVs: -18.0 ± 8.7 mmHg; P = 0.57). Patients showed impaired nutrient tolerance compared with HVs (587.6 ± 80.2 vs 936 ± 66.2 kcal; P = 0.003). All patients and HVs tolerated the catheters and could finalize the study. The measurement of IGP during intragastric ND infusion was well tolerated in children. Nutrient tolerance was reduced in children with FD compared with HVs. In the future, this may be a useful tool to assess GA accommodation and nutrient tolerance in children.

  11. Assessment of the usability of a digital learning technology prototype for monitoring intracranial pressure.

    Science.gov (United States)

    Carvalho, Lilian Regina de; Évora, Yolanda Dora Martinez; Zem-Mascarenhas, Silvia Helena

    2016-08-29

    to assess the usability of a digital learning technology prototype as a new method for minimally invasive monitoring of intracranial pressure. descriptive study using a quantitative approach on assessing the usability of a prototype based on Nielsen's ten heuristics. Four experts in the area of Human-Computer interaction participated in the study. the evaluation delivered eight violated heuristics and 31 usability problems in the 32 screens of the prototype. the suggestions of the evaluators were critical for developing an intuitive, user-friendly interface and will be included in the final version of the digital learning technology. avaliar a usabilidade de um protótipo educacional digital sobre um novo método para monitoração da pressão intracraniana de forma minimamente invasivo para enfermeiros e médicos. estudo descritivo com abordagem quantitativa sobre a avaliação de usabilidade de um protótipo com base nas dez Heurísticas de Nielsen. Participaram quatro especialistas da área de Interação Humano Computador. a avaliação resultou em oito heurísticas violadas e 31 problemas de usabilidade nas 32 telas do protótipo. as sugestões dos avaliadores foram cruciais para o desenvolvimento de uma interface amigável e intuitiva e serão consideradas na versão final da tecnologia educacional digital. evaluar la usabilidad de un prototipo educacional digital sobre un nuevo método para monitorización de la presión intracraneal, de manera mínimamente invasiva. estudio descriptivo con abordaje cuantitativo sobre la evaluación de usabilidad de un prototipo con base en las diez reglas Heurísticas de Nielsen. Participaron cuatro especialistas del área de Interacción Humana Computador. la evaluación resultó en ocho reglas heurísticas violadas y 31 problemas de usabilidad en las 32 pantallas del prototipo. las sugestiones de los evaluadores fueron cruciales para el desarrollo de una interfaz amigable e intuitiva y éstas serán consideradas en la

  12. Predictive validity and reliability of the Braden scale for risk assessment of pressure ulcers in an intensive care unit.

    Science.gov (United States)

    Lima-Serrano, M; González-Méndez, M I; Martín-Castaño, C; Alonso-Araujo, I; Lima-Rodríguez, J S

    2017-02-15

    Contribution to validation of the Braden scale in patients admitted to the ICU, based on an analysis of its reliability and predictive validity. An analytical, observational, longitudinal prospective study was carried out. Intensive Care Unit, Hospital Virgen del Rocío, Seville (Spain). Patients aged 18years or older and admitted for over 24hours to the ICU were included. Patients with pressure ulcers upon admission were excluded. A total of 335 patients were enrolled in two study periods of one month each. None. The presence of gradei-iv pressure ulcers was regarded as the main or dependent variable. Three categories were considered (demographic, clinical and prognostic) for the remaining variables. The incidence of patients who developed pressure ulcers was 8.1%. The proportion of gradei andii pressure ulcer was 40.6% and 59.4% respectively, highlighting the sacrum as the most frequently affected location. Cronbach's alpha coefficient in the assessments considered indicated good to moderate reliability. In the three evaluations made, a cutoff point of 12 was presented as optimal in the assessment of the first and second days of admission. In relation to the assessment of the day with minimum score, the optimal cutoff point was 10. The Braden scale shows insufficient predictive validity and poor precision for cutoff points of both 18 and 16, which are those accepted in the different clinical scenarios. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  13. Assessing the reproducibility of high definition urethral pressure profilometry and its correlation with an air-charged system.

    Science.gov (United States)

    Klünder, Mario; Amend, Bastian; Sawodny, Oliver; Stenzl, Arnulf; Ederer, Michael; Kelp, Alexandra; Sievert, Karl-Dietrich; Feuer, Ronny

    2017-06-01

    Recently, a new urodynamic method for the assessment of stress urinary incontinence called high definition urethral pressure profilometry (HD-UPP) has been introduced. This method combines a novel microtip catheter with advanced signal processing to enable spatial data location and the reconstruction of a pressure image inside the urethra. In order to assess the reproducibility of HD-UPP data, we statistically evaluate HD-UPP datasets and compare them to data from a double balloon air-charged system. Both catheters are used on sedated female minipigs. Data from the microtip catheter are processed through a signal reconstruction algorithm, urodynamic features are extracted, and compared to the air-charged system. Reproducibility of HD-UPP data is assessed by statistically evaluating consecutive, intra-individual datasets. HD-UPP delivers results in agreement with previous comparisons of microtip and air-charged systems. The average deviation of two consecutive, intra-individual pressure images is very low at 7 cm H2 O. HD-UPP provides physicians with detailed information on the pressure distribution inside the urethra. Through comparison with an air-charged catheter, it is shown that HD-UPP delivers results in agreement with previous studies on the comparison of microtip and air-charged catheters. It provides excellent reproducibility, as the difference between sequentially measured profiles from the same minipig is significantly lower than the one between profiles from different minipigs. © 2016 Wiley Periodicals, Inc.

  14. The Berkeley gas-filled separator

    CERN Document Server

    Ninov, V; McGrath, C A

    1998-01-01

    The BGS is being constructed at the 88-Inch Cyclotron at LBNL in Berkeley. The magnetic configuration of the BGS will allow a large angular acceptance and good suppression of primary beam particles. BGS operates as a mass spectrometer with a A/ Delta A approximately =200 and as a gas filled separator at pressures between 0.1-50 hPa. The reaction products recoiling off a thin target will be collected with efficiencies from 10-80at the focal plane. A Monte Carlo simulation program of the ion transport through the gas-filled magnets in combination of 3-dimensional TOSCA field maps has been developed and reproduces closely the experimental behavior of BGS. (9 refs).

  15. Assessment of Pressure Fluctuation Effect for Thermal Fatigue in a T-junction Using Thermo-Hydro Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pyo, Jaebum; Kim, Jungwoo; Huh, Namsu [Seoul National Univ. of Science and Technology, Seoul (Korea, Republic of); Kim, Sunhye [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-10-15

    As a result, when evaluating thermal fatigue for the mixing tee, temperature fluctuation is dominant for this phenomenon, it can be reasonably assumed that the pressure is constant on the pipe inner wall. Recently, thermal fatigue due to mixing of the fluids having different temperatures has been considered as an important issue on the fatigue evaluation of nuclear piping. Mainly, this phenomenon occurs in a T-junction operating with the fluids consisted of different temperatures. Because of the turbulent mixing of hot and cold water, the temperature on the inner wall of the pipe fluctuates rapidly, causing the variation of thermal stresses in the pipe and resulting in high cycle thermal fatigue. In practice, cracking by high cycle thermal fatigue is reported at a T-junction in the residual heat removal system at Civaux unit 1 in France. However, because of irregular flow inside the pipe, the pressure also fluctuates rapidly as well as temperature in the inner wall of the pipe. Therefore, in this paper, three-dimensional thermo-hydro analysis was performed for the mixing tee of the shutdown cooling system of the pressurized water reactor plant, examining the pressure variation at the pipe inner wall. Based on the analysis result, this study aims at assessing the pressure fluctuation effect on the thermal fatigue. In this paper, it is verified that there is pressure fluctuation as well as temperature on the inner wall of mixing tee operating with the fluids having different temperatures. However, since the amplitude of pressure is relatively smaller than design pressure of the shutdown cooling system, the effect wouldn't be important for the thermal fatigue.

  16. Two-dimensional photonic crystals from semiconductor material with polymer filled holes

    Science.gov (United States)

    van der Heijden, Rob; Kjellander, Charlotte; Carlström, Carl-Fredrik; Snijders, Juri; van der Heijden, Rob W.; Bastiaansen, Kees; Broer, Dick; Karouta, Fouad; Nötzel, Richard; van der Drift, Emile; Salemink, Huub W. M.

    2006-04-01

    Polymer filling of the air holes of indiumphosphide based two-dimensional photonic crystals is reported. The filling is performed by infiltration with a liquid monomer and solidification of the infill in situ by thermal polymerization. Complete hole filling is obtained with infiltration under ambient pressure. This conclusion is based both on cross-sectional scanning electron microscope inspection of the filled samples as well as on optical transmission measurements.

  17. The usefulness of contrast during exercise echocardiography for the assessment of systolic pulmonary pressure

    Directory of Open Access Journals (Sweden)

    Cordeiro Ana

    2008-10-01

    Full Text Available Abstract Background The systolic pulmonary artery pressure (PAPs can be accurately estimated, non-invasively, using continuous-wave Doppler (CWD ultrasound measurement of the peak velocity of a tricuspid regurgitant (TR jet. However, it is often difficult to obtain adequate tricuspid regurgitation signals for measurement of PAPs, what could lead to its underestimation. Therefore, utilization of air-blood-saline contrast has been implemented for the improvement of Doppler signal in several clinical contexts. It is now recommended in the evaluation of patients with pulmonary hypertension. Physical activity is severely restricted in patients with PAH, being exertional dypnea the most typical symptom. Exercise stress echo-Doppler imaging allows assessment of the response to exercise. It is an excellent screening test for patients with suspected PAH. Our purpose was to evaluate the value and accuracy of agitated saline with blood contrast echocardiography, in the improvement of the Doppler signal, to quantify PAPs during treadmill exercise-echocardiography. Purpose To evaluate the value of contrast echocardiography, using agitated saline with blood, in the improvement of the Doppler signal used to quantify the pulmonary artery systolic pressure during exercise. Methods From a total of 41 patients (pts, we studied 38 pts (93%, 35 women, aged 54 ± 12 years-old. 27 with the diagnosis of systemic sclerosis, 10 with history of pulmonary embolism and one patient with a suspected idiopathic PAH, who were referred to the Unity of Heart Failure and Pulmonary Hypertension for screening of PAH. According to the Unity protocol, a transthoracic echocardiogram was made, in left decubitus (LD, with evaluation of right ventricle-right atria gradient (RV/RAg. A peripheral venous access was obtained, with a 3-way stopcock and the patients were placed in orthostatism (O, with a new evaluation of RV/RAg. Exercise echocardiography (EE was begun, with evaluation of RV

  18. Using Design of Experiments Methods for Assessing Peak Contact Pressure to Material Properties of Soft Tissue in Human Knee

    Directory of Open Access Journals (Sweden)

    Marjan Bahraminasab

    2013-01-01

    Full Text Available Contact pressure in the knee joint is a key element in the mechanisms of knee pain and osteoarthritis. Assessing the contact pressure in tibiofemoral joint is a challenging mechanical problem due to uncertainty in material properties. In this study, a sensitivity analysis of tibiofemoral peak contact pressure to the material properties of the soft tissue was carried out through fractional factorial and Box-Behnken designs. The cartilage was modeled as linear elastic material, and in addition to its elastic modulus, interaction effects of soft tissue material properties were added compared to previous research. The results indicated that elastic modulus of the cartilage is the most effective factor. Interaction effects of axial/radial modulus with elastic modulus of cartilage, circumferential and axial/radial moduli of meniscus were other influential factors. Furthermore this study showed how design of experiment methods can help designers to reduce the number of finite element analyses and to better interpret the results.

  19. Medication safety: Filling your prescription

    Science.gov (United States)

    ... medicines. Also learn what each medicine looks like. Filling Your Prescriptions Your health plan may require you to use certain pharmacies. ... standards. The website should have clear directions for filling or ... seeing you. Make sure your health plan will cover the cost of using the ...

  20. The inclusion of weld residual stress in fracture margin assessments of embrittled nuclear reactor pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, T.L.; Bass, B.R.; McAfee, W.J.

    1998-01-01

    Analyses were performed to determine the impact of weld residual stresses in a reactor pressure vessel (RPV) on (1) the generation of pressure temperature (P-T) curves required for maintaining specified fracture prevention margins during nuclear plant startup and shutdown, and (2) the conditional probability of vessel failure due to pressurized thermal shock (PTS) loading. The through wall residual stress distribution in an axially oriented weld was derived using measurements taken from a shell segment of a canceled RPV and finite element thermal stress analyses. The P-T curve derived from the best estimate load analysis and a t / 8 deep flaw, based on K{sub Ic}, was less limiting than the one derived from the current methodology prescribed in the ASME Boiler and Pressure Vessel Code. The inclusion of the weld residual stresses increased the conditional probability of cleavage fracture due to PTS loading by a factor ranging from 2 to 4.

  1. ANALYSIS OF THE VACUUM PRESSURE IMPROVEMENT EFFECT ON DEEP SOFT CLAY FOUNDATION COVERED BY UNCONSOLIDATED HYDRAULIC FILL OF SILTY SAND%上覆欠固结吹填粉砂深厚软黏土地基加固效果分析

    Institute of Scientific and Technical Information of China (English)

    唐彤芝; 王海鹏; 孙国峰; 柴犇犇; 沈伟斌

    2015-01-01

    通过对某上覆欠固结吹填粉细砂土深厚软土地基真空预压中真空压力传递和衰减、超静孔隙水压增长和消散、地基表面沉降、土体分层沉降变形特性和规律的分析,研究上覆欠固结吹填粉细砂土层对真空预压软基固结变形的影响。欠固结吹填粉细砂土层有利于下卧深厚软基的排水消压,地基沉降前期快、波动大,中后期收敛稳定快。膜下真空压力表面传递的差异性和波动性较大,向地基深处传递的滞后性和衰减幅度较大。欠固结吹填粉细砂土压缩量较大,吸收了大部分的真空能量,不利于下卧深厚软基的压缩变形。处理后欠固结吹填土的加固效果明显好于下卧软基土体。%It was analyzed the law of the transmission and attenuation of vacuum pressure, the growth and dissipation of excess pore pressure, ground surface settlement, and the deformation characteristic and rules of layered settlement in the deep soft soil foundation covered by unconsolidated hydraulic fill of fine silty sand, and also studied the effects on consolidation deformation of the soft soil foundation covered by unconsolidated hydraulic fill of fine silt layer. Unconsolidated hydraulic fill of fine silty sand was conducive to the pore pressure dissipation and the drainage of underlying deep soft foundation.The foundation settlement was fast with fluctuation in the early stage, convergence and stability in the middle and later stage.When vacuum pressure under membrane transferred on the surface, its difference and fluctuation were large, when it passed to the deep foundation, its hysteresis and attenuation range was large.The compression of unconsolidated hydraulic fill of silty sand was large, and most of the vacuum energy was absorbed.The characteristic was not conducive to the compression deformation of underlying deep soft foundation. After treatment, the reinforcing effect of the unconsolidated hydraulic fill of

  2. Non-invasive assessment of pulmonary arterial pressure in healthy neonates.

    OpenAIRE

    Skinner, J. R.; Boys, R J; Hunter, S; Hey, E N

    1991-01-01

    Doppler echocardiograms were carried out on 51 healthy babies three times during the first 72 hours of life to estimate pulmonary arterial systolic pressure by measuring regurgitant tricuspid jet velocity and applying the Bernoulli equation. Tricuspid regurgitation was detected at some stage in all preterm babies and most of those born at full term. Pulmonary arterial pressure could be measured from peak regurgitant velocity in babies with pansystolic regurgitation. The incidence of pansystol...

  3. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.

    2014-04-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  4. [Indices of static and dynamic components of pressure load (assessed by 24-hour blood pressure monitoring) and the state of renal function in patients with essential hypertension].

    Science.gov (United States)

    Zelveian, P A; Buniatian, M S; Oshchepkova, E V; Lazareva, N V; Rogoza, A N

    2011-01-01

    Aim of this study was to evaluate possible relationship between parameters of blood pressure (BP) profile and glomerular filtration rate in patients (pts) with I-II stage essential hypertension (EH). Material and methods. We studied 120 pts (97 men), aged 23-65 (50,2+/-0,6) years with I (n=98) and II (n=22) stage EH. In BP profile (SL-90207) we calculated 24-hour, daytime, nighttime values of systolic, diastolic, pulse pressures (SBP, DBP, PP), time load (TL), variability and nocturnal fall (NF) of BP. The state of renal function was assessed by measurement of glomerular filtration rate (GFR) calculated by the Cockcroft formula. Results. After nonlinear statistical analysis by Gauss-Newton all patients were divided into three groups according to GFR tertiles. Significant differences were found between these groups by 24-hour, nighttime and daytime values of SBP and DBP. Values of SBP were the lowest in group II. In group II lowest values of PP were also observed, but statistically significant differences were found only in nocturnal PP values between groups II and III. There were no significant differences between groups by TL and NF of BP. In group Ill (high GFR) variability of daytime values of SBP and DBF were significantly higher. Univariate correlation analysis showed statistically significant negative relationship between GFR and nocturnal PP in patients with lowest level of GFR. Positive correlations between nocturnal values of PP and GFR in groups II and III were also observed. Conclusion. These results indicated the presence of strong relationship between high values of nocturnal PP and decreasing of glomerular filtration rate in patients with EH and thus confirmed significance of "constant" and "dynamic" components of pressure load as a marker of impairment of renal function.

  5. Cuspal deflection and microleakage in premolar teeth restored with bulk-fill flowable resin-based composite base materials

    DEFF Research Database (Denmark)

    Moorthy, A; Hogg, C H; Dowling, A H;

    2012-01-01

    To assess the cuspal deflection and cervical microleakage of standardised Class II cavities incrementally filled with a dimethacrylate RBC or bulk-fill flowable RBC bases.......To assess the cuspal deflection and cervical microleakage of standardised Class II cavities incrementally filled with a dimethacrylate RBC or bulk-fill flowable RBC bases....

  6. Design and research on reliability-validity for 3S intraoperative risk assessment scale of pressure sore.

    Science.gov (United States)

    Gao, Xing-lian; Hu, Juan-juan; Ma, Qiong; Wu, He-yu; Wang, Zeng-yan; Li, Ting-ting; Shen, Jian-hui; Yang, Ying

    2015-04-01

    The reliability and validity of risk assessment scale (RAS) of pressure sore during 3S surgery were investigated. RAS of pressure sore was designed independently during 3S surgery. Five operating room nursing experts were selected to consult and detect face validity. Convenient and purposive sampling of 707 samples was conducted. Cronbach's alpha was used to measure content reliability and evaluate the internal consistence of RAS. The structural reliability was investigated by exploratory factor analysis method. The results showed that the content validity index was 0.92, and Cronbach's alpha of content reliability was 0.71. Structural validity, detected by Bartlett sphericity test, was 135.3 for 707 samples with the difference being statistically significant (Pvalidity and reliability, and it could be used for evaluating and screening the high risk patients with pressure sores during surgery in order to efficiently reduce the occurrence of pressure sore during surgery. RAS of pressure sore for 3S surgery is worth to be popularized.

  7. The 2014 Canadian Hypertension Education Program recommendations for blood pressure measurement, diagnosis, assessment of risk, prevention, and treatment of hypertension.

    Science.gov (United States)

    Dasgupta, Kaberi; Quinn, Robert R; Zarnke, Kelly B; Rabi, Doreen M; Ravani, Pietro; Daskalopoulou, Stella S; Rabkin, Simon W; Trudeau, Luc; Feldman, Ross D; Cloutier, Lyne; Prebtani, Ally; Herman, Robert J; Bacon, Simon L; Gilbert, Richard E; Ruzicka, Marcel; McKay, Donald W; Campbell, Tavis S; Grover, Steven; Honos, George; Schiffrin, Ernesto L; Bolli, Peter; Wilson, Thomas W; Lindsay, Patrice; Hill, Michael D; Coutts, Shelagh B; Gubitz, Gord; Gelfer, Mark; Vallée, Michel; Prasad, G V Ramesh; Lebel, Marcel; McLean, Donna; Arnold, J Malcolm O; Moe, Gordon W; Howlett, Jonathan G; Boulanger, Jean-Martin; Larochelle, Pierre; Leiter, Lawrence A; Jones, Charlotte; Ogilvie, Richard I; Woo, Vincent; Kaczorowski, Janusz; Burns, Kevin D; Petrella, Robert J; Hiremath, Swapnil; Milot, Alain; Stone, James A; Drouin, Denis; Lavoie, Kim L; Lamarre-Cliche, Maxime; Tremblay, Guy; Hamet, Pavel; Fodor, George; Carruthers, S George; Pylypchuk, George B; Burgess, Ellen; Lewanczuk, Richard; Dresser, George K; Penner, S Brian; Hegele, Robert A; McFarlane, Philip A; Khara, Milan; Pipe, Andrew; Oh, Paul; Selby, Peter; Sharma, Mukul; Reid, Debra J; Tobe, Sheldon W; Padwal, Raj S; Poirier, Luc

    2014-05-01

    Herein, updated evidence-based recommendations for the diagnosis, assessment, prevention, and treatment of hypertension in Canadian adults are detailed. For 2014, 3 existing recommendations were modified and 2 new recommendations were added. The following recommendations were modified: (1) the recommended sodium intake threshold was changed from ≤ 1500 mg (3.75 g of salt) to approximately 2000 mg (5 g of salt) per day; (2) a pharmacotherapy treatment initiation systolic blood pressure threshold of ≥ 160 mm Hg was added in very elderly (age ≥ 80 years) patients who do not have diabetes or target organ damage (systolic blood pressure target in this population remains at hypertension to only those ≥ 50 years of age. The 2 new recommendations are: (1) advice to be cautious when lowering systolic blood pressure to target levels in patients with established coronary artery disease if diastolic blood pressure is ≤ 60 mm Hg because of concerns that myocardial ischemia might be exacerbated; and (2) the addition of glycated hemoglobin (A1c) in the diagnostic work-up of patients with newly diagnosed hypertension. The rationale for these recommendation changes is discussed. In addition, emerging data on blood pressure targets in stroke patients are discussed; these data did not lead to recommendation changes at this time. The Canadian Hypertension Education Program recommendations will continue to be updated annually.

  8. Pressurization Risk Assessment of CO2 Reservoirs Utilizing Design of Experiments and Response Surface Methods

    Science.gov (United States)

    Guyant, E.; Han, W. S.; Kim, K. Y.; Park, E.; Han, K.

    2015-12-01

    Monitoring of pressure buildup can provide explicit information on reservoir integrity and is an appealing tool, however pressure variation is dependent on a variety of factors causing high uncertainty in pressure predictions. This work evaluated pressurization of a reservoir system in the presence of leakage pathways as well as exploring the effects of compartmentalization of the reservoir utilizing design of experiments (Definitive Screening, Box Behnken, Central Composite, and Latin Hypercube designs) and response surface methods. Two models were developed, 1) an idealized injection scenario in order to evaluate the performance of multiple designs, and 2) a complex injection scenario implementing the best performing design to investigate pressurization of the reservoir system. A holistic evaluation of scenario 1, determined that the Central Composite design would be used for the complex injection scenario. The complex scenario evaluated 5 risk factors: reservoir, seal, leakage pathway and fault permeabilities, and horizontal position of the pathway. A total of 60 response surface models (RSM) were developed for the complex scenario with an average R2 of 0.95 and a NRMSE of 0.067. Sensitivity to the input factors was dynamic through space and time; at the earliest time (0.05 years) the reservoir permeability was dominant, and for later times (>0.5 years) the fault permeability became dominant for all locations. The RSM's were then used to conduct a Monte Carlo Analysis to further analyze pressurization risks, identifying the P10, P50, P90 values. This identified the in zone (lower) P90 values as 2.16, 1.77, and 1.53 MPa and above zone values of 1.35, 1.23, 1.09 MPa for monitoring locations 1, 2, and 3, respectively. In summary, the design of experiments and response surface methods allowed for an efficient sensitivity and uncertainty analysis to be conducted permitting a complete evaluation of the pressurization across the entire parameter space.

  9. Modeling simulation and experimental validation for mold filling process

    Institute of Scientific and Technical Information of China (English)

    HOU Hua; JU Dong-ying; MAO Hong-kui; D. SAITO

    2006-01-01

    Based on the continuum equation, momentum conservation and energy conservation equations, the numerical model of turbulent flow filling was introduced; the 3-D free surface vof method was improved. Whether or not the numerical simulation results are reasonable, it needs corresponding experimental validations. General experimental techniques for casting fluid flow process include: thermocouple tracking location method, hydraulic simulating method, heat-resistant glass window method and X-ray observation etc. The hydraulic analogue experiment with DPIV technique is arranged to validate the fluent flow program for low-pressure casting with 0.1×105 Pa and 0.6×105 Pa pressure visually. By comparing the flow head, liquid surface, flow velocity, it is found that the filling pressure value influences the flow state strongly. With the increase of the filling pressure, the fluid flow state becomes unstable, the flow head becomes higher, and the filling time is reduced. The simulated results are accordant with the observed results approximately, which can prove the reasonability of our numerical program for filling process further.

  10. Filling defect artefacts in magnetic resonance urography

    Energy Technology Data Exchange (ETDEWEB)

    Girish, G.; Chooi, W.K.; Morcos, S.K. [Department of Diagnostic Imaging, Northern General Hospital, Sheffield Teaching Hospitals NHS Trust, S5 7AU, Sheffield (United Kingdom)

    2004-01-01

    The aim of this study was to determine the prevalence of filling defect artefacts (FDA) in magnetic resonance urography (MRU). Retrospectively, we assessed MRU examinations of 45 patients with neurogenic bladder dysfunction (21 men, 24 women; mean age 35 years, age range 18-71 years). The MRU was performed 30 min after intramuscular injection of 20 mg frusemide using heavily T2-weighted fast-spin-echo techniques [axial, thick coronal slab, coronal maximum intensity projection (MIP) images] with fat saturation. The images were reviewed by two observers to determine the presence of filling defects and dilatation of pelvicalyceal system and ureters. The filling defects were classified into central, eccentric and complete. Clinical course and plain films were reviewed to determine significance of the detected filling defects. True filling defects were observed in 5 patients (11%) and all due to stones seen on the plain radiograph of the abdomen. Filling defects artefacts (FDAs) were seen in 23 patients (51%; 17 pelvicalyceal system, 17 upper third of ureters, 7 mid ureters and 1 distal ureter). No stones were seen on the plain radiograph of these patients and they had a favourable clinical course for over 24 months. The true filling defects were large in size, eccentric in position and seen in more than one sequence of the MRU examination (axial, n=5; slab, n=5; and MIP, n=4). Four (80%) of the patients with true defects and 21 (91%) of those with FDAs had dilatation of the pelvicalyceal system and ureters. The FDAs were small in size, centrally placed (74%) and always seen in axial images, rarely in slab images (2 cases) and not seen in MIP images. Artefactual filling defects can be seen in MRU examinations. The cause of the FDAs is not fully explained and could be secondary to turbulent and fast flow of the urine. Some of the FDAs seen in the calyces could be due to the tips of the papillae. Awareness of such defects obviates misinterpretation and prevents

  11. Probabilistic Assessment of Above Zone Pressure Predictions at a Geologic Carbon Storage Site

    Science.gov (United States)

    Namhata, Argha; Oladyshkin, Sergey; Dilmore, Robert M.; Zhang, Liwei; Nakles, David V.

    2016-12-01

    Carbon dioxide (CO2) storage into geological formations is regarded as an important mitigation strategy for anthropogenic CO2 emissions to the atmosphere. This study first simulates the leakage of CO2 and brine from a storage reservoir through the caprock. Then, we estimate the resulting pressure changes at the zone overlying the caprock also known as Above Zone Monitoring Interval (AZMI). A data-driven approach of arbitrary Polynomial Chaos (aPC) Expansion is then used to quantify the uncertainty in the above zone pressure prediction based on the uncertainties in different geologic parameters. Finally, a global sensitivity analysis is performed with Sobol indices based on the aPC technique to determine the relative importance of different parameters on pressure prediction. The results indicate that there can be uncertainty in pressure prediction locally around the leakage zones. The degree of such uncertainty in prediction depends on the quality of site specific information available for analysis. The scientific results from this study provide substantial insight that there is a need for site-specific data for efficient predictions of risks associated with storage activities. The presented approach can provide a basis of optimized pressure based monitoring network design at carbon storage sites.

  12. Structural integrity assessments of high pressure pipelines with axial flaws using a micromechanics model

    Energy Technology Data Exchange (ETDEWEB)

    Dotta, Fernando; Ruggieri, Claudio

    2004-09-01

    This study extends a micromechanics approach based upon the computational cell methodology to model ductile crack extension of longitudinal crack-like defects in a high strength pipeline steel. Laboratory testing of an API 5L X60 steel at room temperature using standard, deep crack C(T) specimens provides the data needed to measure the crack growth resistance curve for the material. A simple scheme to calibrate material-specific parameters for the cells employs this measured R-curve. A central focus of the paper is the application of the cell methodology to predict experimentally measured burst pressures for longitudinally pre-cracked pipe specimens. The experimental program includes large-diameter pipe specimens with different crack depth (a) and crack size (2c). Plane-strain computations are conducted on detailed finite element models for the pipe specimens to describe crack extension with increased pressure. The cell model predictions of crack growth response and burst pressure predictions are in good agreement with experimental measurements for the tested pipes. The present methodology holds significant promise as an engineering tool to simulate ductile crack growth and to predict the burst pressure of high pressure pipelines containing crack-like defects.

  13. Quantitative assessment of pressure sore generation and healing through numerical analysis of high-frequency ultrasound images

    Directory of Open Access Journals (Sweden)

    Sahar Moghimi, MS

    2010-04-01

    Full Text Available This article focuses on the development of a method to quantitatively assess the healing process of artificially induced pressure sores using high-frequency (20 MHz ultrasound images. We induced sores in guinea pigs and monitored predefined regions on days 3, 7, 14, and 21 after sore generation. We extracted relevant parameters regarding the tissue echographic structure and attenuation properties. We examined tissue healing by defining a healing function that used the extracted parameters. We verified the significance of the extracted features by using analysis of variance and multiple comparison tests. The features displayed ascending/descending behavior during wound generation and reverse behavior during healing. We optimized the parameters of our healing function by using a pattern search method. We tested the efficiency of the optimized values by calculating the healing function value on assessment days and then comparing these results with the expected pattern of changes in the tissue conditions after removing the applied pressure. The results of this study suggest that the methodology developed may be a viable tool for quantitative assessment of pressure sores during their early generation as well as during healing stages.

  14. Quantitative assessment of pressure sore generation and healing through numerical analysis of high-frequency ultrasound images.

    Science.gov (United States)

    Moghimi, Sahar; Miran Baygi, Mohammad Hossein; Torkaman, Giti; Mahloojifar, Ali

    2010-01-01

    Abstract-This article focuses on the development of a method to quantitatively assess the healing process of artificially induced pressure sores using high-frequency (20 MHz) ultrasound images. We induced sores in guinea pigs and monitored predefined regions on days 3, 7, 14, and 21 after sore generation. We extracted relevant parameters regarding the tissue echographic structure and attenuation properties. We examined tissue healing by defining a healing function that used the extracted parameters. We verified the significance of the extracted features by using analysis of variance and multiple comparison tests. The features displayed ascending/descending behavior during wound generation and reverse behavior during healing. We optimized the parameters of our healing function by using a pattern search method. We tested the efficiency of the optimized values by calculating the healing function value on assessment days and then comparing these results with the expected pattern of changes in the tissue conditions after removing the applied pressure. The results of this study suggest that the methodology developed may be a viable tool for quantitative assessment of pressure sores during their early generation as well as during healing stages.

  15. Cardiac output assessment using oxygen consumption estimated from the left ventricular pressure-volume area.

    Science.gov (United States)

    Negroni, Jorge A; Lascano, Elena C; Bertolotti, Alejandro M; Gómez, Carmen B; Rodríguez Correa, Carlos A; Favaloro, Roberto R

    2010-01-01

    Use of a majority of structural variables (age, sex, height) to estimate oxygen consumption in the calculation of cardiac output (CO) by the Fick principle does not account for changes in physiological conditions. To improve this limitation, oxygen consumption was estimated based on the left ventricular pressure-volume area. A pilot study with 10 patients undergoing right cardiac catheterization showed that this approach was successful to estimate CO (r=0,73, vs. thermodilution measured CO). Further essays changing end-diastolic-volume in the pressure-volume area formula by body weight or body surface area showed that this last yielded the best correlation with the thermodilution measured CO (slope=1, ordinate =0.01 and r=0.93). These preliminary results indicate that use of a formula originated from the pressure-volume-area concept is a good alternative to estimate oxygen consumption for CO calculation.

  16. Early nocturnal blood pressure changes in diabetic autonomic neuropathy assessed by Fourier series.

    Science.gov (United States)

    Germano, G; Caparra, A; Valentino, S; Germano, U; Coia, F; Cassone-Faldetta, M; De Mattia, G; Santucci, A; Balsano, F

    1993-08-01

    The 24 h periodic pattern of blood pressure was studied in 44 patients with diabetes mellitus (14 type 1, 30 type 2; mean duration of disease 6.5 +/- 1.8 years) in good metabolic control but with abnormal cardiovascular reflex responses; of these 21 were normotensive and 23 hypertensive. All had abnormal responses to at least two out of four tests: deep breathing, lying to standing, Valsalva manoeuvre and postural hypotension. Two sex- and age-matched groups, consisting of 20 normotensive and 20 hypertensive diabetic patients without dysautonomia, were studied as controls. Each patient underwent ambulatory blood pressure monitoring for at least 24 h, using an auscultatory automatic device. Data were analysed using the sum of three periodic functions (Fourier partial sum). In the diabetic normotensive groups, the absolute blood pressure fell to its night-time minimum more rapidly, and increased to its morning maximum more slowly, in those with abnormal cardiovascular reflexes than in the controls (nightly blood pressure decrease -5.8/-4.7 vs. -3.8/-4.0 mmHg/h; increase 4.7/3.6 vs. 5.9/6.1 mmHg/h). The same behaviour was found in both hypertensive groups but the amplitude of the differences was more marked (blood pressure nocturnal decrease -7.7/-7.1 vs. -4.3/-3.9 mmHg/h; increase 3.2/2.1 vs. 5.8/4.3 mmHg/h). This analysis of 24 h ambulatory blood pressure data may be of value in diagnosis and evaluation of autonomic deficits.

  17. The diastolic flow velocity-pressure gradient relation and dpv50 to assess the hemodynamic significance of coronary stenoses.

    Science.gov (United States)

    Marques, Koen M J; van Eenige, Machiel J; Spruijt, Hugo J; Westerhof, Nico; Twisk, Jos; Visser, Cees A; Visser, Frans C

    2006-12-01

    To evaluate the hemodynamic impact of coronary stenoses, the fractional (FFR) or coronary flow velocity reserve (CFVR) usually is measured. The combined measurement of instantaneous flow velocity and pressure gradient (v-dp relation) is rarely used in humans. We derived from the v-dp relation a new index, dp(v50) (pressure gradient at flow velocity of 50 cm/s), and compared the diagnostic performance of dp(v50), CFVR, and FFR. Before coronary angiography was performed, patients underwent noninvasive stress testing. In all coronary vessels with an intermediate or severe stenosis, the flow velocity, aortic, and distal coronary pressure were measured simultaneously with a Doppler and pressure guidewire after induction of hyperemia. After regression analysis of all middiastolic flow velocity and pressure gradient data, the dp(v50) was calculated. With the use of the results of noninvasive stress testing, the dp(v50) cutoff value was established at 22.4 mmHg. In 77 patients, 124 coronary vessels with a mean 39% (SD 19) diameter stenosis were analyzed. In 43 stenoses, ischemia was detected. We found a sensitivity, specificity, and accuracy of 56%, 86%, and 76% for CFVR; 77%, 99%, and 91% for FFR; and 95%, 95%, and 95% for dp(v50). To establish that dp(v50) is not dependent on maximal hyperemia, dp(v50) was recalculated after omission of the highest quartile of flow velocity data, showing a difference of 3%. We found that dp(v50) provided the highest sensitivity and accuracy compared with FFR and CFVR in the assessment of coronary stenoses. In contrast to CFVR and FFR, assessment of dp(v50) is not dependent on maximal hyperemia.

  18. Assessment of Well Safety from Pressure and Temperature-Induced Damage during CO2 Injection in Deep Saline Aquifers

    Science.gov (United States)

    Singh, A. K.; Delfs, J.; Goerke, U.; Kolditz, O.

    2013-12-01

    Carbon dioxide Capture and Storage (CCS) technology is known for disposing a specific amount of CO2 from industrial release of flue gases into a suitable storage where it stays for a defined period of time in a safe way. Types of storage sites for CO2 are depleted hydrocarbon reservoirs, unmineable coal seams and saline aquifers. In this poster, we address the problem of CO2 sequestration into deep saline aquifers. The main advantage of this kind of site for the CO2 sequestration is its widespread geographic distribution. However, saline aquifers are very poorly characterized and typically located at one kilometer depth below the earth's surface. To demonstrate that supercritical CO2 injection into deep saline aquifers is technically and environmentally safe, it is required to perform thermo-hydro-mechanical analysis of failure moods with numerical models. In the poster, we present simple process-catching benchmark for testing the scenario of compressed CO2 injection into a multi- layered saline aquifer.The pores of the deformable matrix are initially filled with saline water at hydrostatic pressure and geothermal temperature conditions. This benchmark investigates (i) how the mechanical and thermal stresses enhance the permeability for CO2 migration; and (ii) subsequent failures mode, i.e., tensile, and shear failures. The tensile failure occurs when pore fluid pressure exceeds the principle stress whereas the Mohr-Coulomb failure criterion defines the shear failure mode. The thermo-hydro-mechanical (THM) model is based on a ';multi-componential flow' module . The coupled system of balance equations is solvedin the monolithic way. The Galerkin finite element approach is used for spatial discretization, whereas temporal discretization is performed with a generalized single step scheme. This numerical module has been implemented in the open-source scientific software OpenGeoSys.

  19. [Validation of EMINA and EVARUCI scales for assessing the risk of developing pressure ulcers in critical patients].

    Science.gov (United States)

    Roca-Biosca, A; Garcia-Fernandez, F P; Chacon-Garcés, S; Rubio-Rico, L; Olona-Cabases, M; Anguera-Saperas, L; Garcia-Grau, N; Tuset-Garijo, G; de Molina-Fernández, I; Velasco-Guillen, M C

    2015-01-01

    To contribute to the validation of the EMINA and EVAUCI scales for assessing the risk of pressure ulcers in the critical patient and compare their predictive capacity in this same context. Prospective study from December 2012 until June 2013. Polyvalent intensive care unit of 14 beds in a reference hospital for two sanitary areas. patients of 18 years of age or older and without pressure ulcers were included. They were followed until development of a pressure ulcer of grade I or greater, medical discharge, death or 30 days. presence of ulcers, daily score of the risk of developing pressure ulcers through EMINA and EVARUCI evaluation. The validity of both scales was calculated using sensitivity, specificity, and positive and negative predictive value. The level of significance was P≤0.05. A total of 189 patients were evaluated. 67.2% were male with a mean age of 59.4 (DE: 16,8) years old, 53 (28%) developed pressure ulcers, being the incidence rate of 41 ulcers per 1000 admission days. The mean day of diagnosis was 7.7 days (DE: 4,4) and the most frequent area was the sacrum. The sensitivity and specificity for the mean of observations was 94.34 (IC95% 87.17-100) and 33.33 (IC95% 25.01-41.66) for the EMINA scale for a risk>10 and 92.45 (IC95% 84.40-100) and 42.96 (IC95% 34.24-51.68) for the EVARUCI scale for a risk of>11. No differences were found in predictive capacity of both scales. For sensitivities>90%the scales show to be insufficiently specific in the pressure ulcer risk detection in critical patients. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  20. The Effects of Different Insufflation Pressures on Liver Functions Assessed with LiMON on Patients Undergoing Laparoscopic Cholecystectomy

    Directory of Open Access Journals (Sweden)

    H. Barıs Eryılmaz

    2012-01-01

    Full Text Available Purpose. Laparoscopic cholecystectomy has been accepted as an alternative to laparotomy, but there is still controversy regarding the effects of pneumoperitoneum on splanchnic and hepatic perfusion. We assessed the effects of different insufflation pressures on liver functions by using indocyanine green elimination tests (ICG-PDR. Methods. We analyzed 43 patients who were scheduled for laparoscopic cholecystectomy. The patients were randomly allocated to two groups. In Group I, the operation was performed using 10 mmHg pressure pneumoperitoneum. In Group II, 14 mmHg pressure pneumoperitoneum was used. The ICG-PDR measurements were made after induction (ICG-PDR 1 and after the end of the operation (ICG-PDR 2. Serum aspartate aminotransferase (AST, alanine aminotransferase (ALT, and total bilirubin levels were all recorded preoperatively, 1 hour, and postoperative 24 hours after surgery. Results. The ICG-PDR 1 values for Groups I and II were as follows: 26.78±4.2% per min versus 26.01±2.4% per min (>0.05. ICG-PDR 2 values were found to be 25.63±2.1% per min in Group I versus 19.06±2.2% per min in Group II (0.05. Conclusion. In conclusion, the results show that 14 mmHg pressure pneumoperitoneum decreased the blood flow to the liver and increased postoperative 1st-hour serum AST and ALT levels. We think that 10 mmHg pressure pneumoperitoneum is superior to 14 mmHg pressure pneumoperitoneum in laparoscopic cholecystectomy.

  1. Gastric yield pressure and gastric yield volume to assess anti-reflux barrier in a porcine model.

    Science.gov (United States)

    Duarte, Marcos E S; Freitag, Carmen P F; Fornari, Fernando; Kruel, Cleber R P; Sanches, Paulo R S; Thomé, Paulo R O; Callegari-Jacques, Sidia M; Möllerke, Roseli O; Vicente, Yvone A M V A; Goldani, Helena A S; Barros, Sérgio G S

    2013-04-01

    Anti-reflux barrier (ARB) resistance may be useful to test new treatments for gastroesophageal reflux (GER). The ARB has been estimated by increasing gastric yield pressure (GYP) and gastric yield volume (GYV) in animal models but has not been validated. This study aimed to develop an experimental model suitable for assessing the ARB resistance to increasing intragastric pressure and volume and its reproducibility in a seven-day interval. Ten two-month-old female Large-White swine were studied. Intragastric pressure and volume were recorded using a digital system connected to a Foley catheter inserted through gastrostomy into the stomach. GYP and GYV were defined as the gastric pressure and volume able to yield gastric contents into the esophagus detected by esophageal pH. A sudden pH drop below 3 sustained during 5 min was considered diagnostic for gastric yield. Animals were studied again after seven days. On days 0 and 7, there were no significant differences for GYP (mean ± SD = 7.66 ± 3.02 mmHg vs. 7.07 ± 3.54 mmHg, p = .686) and GYV (636.70 ± 216.74 ml vs. 608.30 ± 276.66 ml; p = .299), respectively. Concordance correlation coefficient (ρc) was significant for GYP (ρc = 0.634, 95% CI = 0.141-0.829, p = .006), but not for GYV (ρc = 0.291, 95% CI = -0.118 to 0.774, p = .196). This study demonstrated an experimental model, assessing the ARB resistance. GYP seems to be a more reliable parameter than GYV for assessment of ARB resistance.

  2. A freshwater biodiversity hotspot under pressure - assessing threats and identifying conservation needs for ancient Lake Ohrid

    Science.gov (United States)

    Kostoski, G.; Albrecht, C.; Trajanovski, S.; Wilke, T.

    2010-12-01

    Immediate conservation measures for world-wide freshwater resources are of eminent importance. This is particularly true for so-called ancient lakes. While these lakes are famous for being evolutionary theatres, often displaying an extraordinarily high degree of biodiversity and endemism, in many cases these biota are also experiencing extreme anthropogenic impact. Lake Ohrid, a major European biodiversity hotspot situated in a trans-frontier setting on the Balkans, is a prime example for a lake with a magnitude of narrow range endemic taxa that are under increasing anthropogenic pressure. Unfortunately, evidence for a "creeping biodiversity crisis" has accumulated over the last decades, and major socio-political changes have gone along with human-mediated environmental changes. Based on field surveys, monitoring data, published records, and expert interviews, we aimed to (1) assess threats to Lake Ohrids' (endemic) biodiversity, (2) summarize existing conservation activities and strategies, and (3) outline future conservation needs for Lake Ohrid. We compiled threats to both specific taxa (and in cases to particular species) as well as to the lake ecosystems itself. Major conservation concerns identified for Lake Ohrid are: (1) watershed impacts, (2) agriculture and forestry, (3) tourism and population growth, (4) non-indigenous species, (5) habitat alteration or loss, (6) unsustainable exploitation of fisheries, and (7) global climate change. Among the major (well-known) threats with high impact are nutrient input (particularly of phosphorus), habitat conversion and silt load. Other threats are potentially of high impact but less well known. Such threats include pollution with hazardous substances (from sources such as mines, former industries, agriculture) or climate change. We review and discuss institutional responsibilities, environmental monitoring and ecosystem management, existing parks and reserves, biodiversity and species measures, international

  3. Assessment of the advantages of a residual heat removal system inside the reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, G.M.

    1995-12-31

    In the framework of research on diversified means for removing the residual heat from pressurized water reactors, the CEA is studying a passive system called RRP (Refroidissement du Reacteur au Primaire, or primary circuit cooling system), which includes integrated heat-exchangers and a layout of the internal structures so as to obtain convection from the primary circuit inside the vessel, whatever the state of the loops. This system is operational for all primary circuit temperatures and pressures, as well as for a wide range of conditions: it is independent of the state of the loops, even if the volume of water in the primary circuit is small, it is compatible with either a passive or an active operation mode, and compatible with any other decay heat removal systems. An evaluation is presented here of the performance of the RRP system in the event of a small primary circuit break in a totally passive operation mode without the intervention of another system. The results of this evaluation show the interest of such a system: a clear increase of the time-delay for the implementation of a low pressure safety injection system, no need for the use of a high pressure safety injection system. (author). 4 refs., 7 figs., 1 tab.

  4. A modelling framework to assess the effect of pressures on river abiotic habitat conditions and biota

    NARCIS (Netherlands)

    Kail, Jochem; Guse, Björn; Radinger, Johannes; Schröder, Maria; Kiesel, Jens; Kleinhans, Maarten; Schuurman, Filip; Fohrer, Nicola; Hering, Daniel; Wolter, Christian

    2015-01-01

    River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a model

  5. ASSESSING THE EFFECTIVENESS OF LOW PRESSURE ULTRAVIOLET LIGHT FOR INACTIVATING HELICOBACTER PYLORI

    Science.gov (United States)

    Three strains of Helicobacter pylori were exposed to ultraviolet (UV) light from a low-pressure source to determine log inactivation versus applied fluence. Results indicate that H. pylori is readily inactivated at UV fluences typically used in water treatment r...

  6. ASSESSING THE EFFECTIVENESS OF LOW PRESSURE ULTRAVIOLET LIGHT FOR INACTIVATING HELICOBACTER PYLORI

    Science.gov (United States)

    Three strains of Helicobacter pylori were exposed to ultraviolet (UV) light from a low-pressure source to determine log inactivation versus applied fluence. Results indicate that H. pylori is readily inactivated at UV fluences typically used in water treatment r...

  7. The urethral closure function in continent and stress urinary incontinent women assessed by urethral pressure reflectometry

    DEFF Research Database (Denmark)

    Saaby, Marie-Louise

    2014-01-01

    . The technique involves insertion of only a small, light and flexible polyurethane bag in the urethra and therefore avoids the common artifacts encountered with conventional methods. The UPR parameters can be obtained at a specific site of the urethra, e.g. the high pressure zone, and during various...

  8. Risk assessment of physiological effects of atmospheric composition and pressure in Constellation vehicles

    Science.gov (United States)

    Scheuring, Richard; Conkin, Johnny; Jones, Jeffrey A.; Gernhardt, Michael L.

    Introduction: To limit the risk of fire and reduce denitrogenation time to prevent decompression sickness to support frequent extravehicular activities on the Moon, a hypobaric (PB=414mmHg) and mildly hypoxic ( ppO2=132mmHg, 32% O2-68%N2) living environment is considered for the Crew Exploration Vehicle (CEV) and Lunar Surface Access Module (LSAM). With acute change in ppO2 from 145-178mmHg at standard vehicular operating pressure to less than 125mmHg at desired lunar surface vehicular operating pressures, there is the possibility that some crewmembers may develop symptoms of Acute Mountain Sickness (AMS). The signs and symptoms of AMS (headache plus nausea, dizziness, fatigue, or sleeplessness) could impact crew health and performance on lunar surface missions. Methods: We performed a literature review on the topic of the physiological effects of reduced ppO2 and absolute pressure. The results of nine studies were evaluated. Results: There is evidence for an absolute pressure effect per se on AMS, so the higher the altitude for a given hypoxic alveolar oxygen (O2) partial pressure (PAO2), the greater the AMS response is. Between 7% and 25% of adults may experience mild AMS near 2000 m altitude following a rapid ascent from sea level while breathing air (6500 ft, acute PAO2=75mmHg). The operational experience with the Shuttle staged denitrogenation protocol at 528mmHg (3048 m) while breathing 26.5% O2 (acute PAO2=85mmHg) in astronauts adapting to microgravity suggests a similar likely experience in the proposed CEV environment. Conclusions: We believe the risk of mild AMS is greater given a PAO2 of 77mmHg at 4876 m altitude while breathing 32% O2 than at 1828 m altitude while breathing 21% O2. Only susceptible astronauts would develop mild and transient AMS with prolonged exposure to 414 mmHg (4876 m) while breathing 32% O2 (acute PAO2=77mmHg). So the following may be employed for operational risk reduction: (1) develop procedures to increase PB as needed in the

  9. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  10. Gas-filled double glazing

    Energy Technology Data Exchange (ETDEWEB)

    Goesele, K.; Schuele, W.; Lakatos, B.

    1982-01-01

    On the basis of the results of experiments the sonar and thermal properties of insulated double glazing filled with gas are tested. The sound insulation properties of double glazing can be improved by introducing a gas of a heavy specific weight, such as CO/sub 2/ or SF/sub 6/ into the hollow space. Even gases with a light specific weight produce an improvement in sound insulation; light gases diffuse outwards much more rapidly, however, and can thus be eliminated for practical purposes. The combination of a gas-filled space between the panes and the use of sufficiently heavy compound panes were tested. The thermal properties of insulated double glazing filled with specifically heavy gas gave favourable results with a lower heat transition coefficient. The use of gas to fill double glazing has a particularly favourable effect if the panes are given a heat-reflecting coating in synthetic frames.

  11. Evacuation from smoke filled corridors

    NARCIS (Netherlands)

    Janse, E.W.; Leur, P.H.E. van de; Oerle, N.J. van

    1998-01-01

    underpinning compartmentation requirements in the Dutch regulations is that people can and will go through 30 m of smoke filled space. The hypothesis leads to the requirement that corridors are divided in compartments with a maximum length of 30 meters.

  12. Assessment of pore pressures and specific storage within sedimentary strata overlying underground mines

    Science.gov (United States)

    Timms, W.; David, K.; Barbour, L. S.

    2016-12-01

    Realistic values of specific storage (Ss) for groundwater systems are important to determine the spatial extent and timing of c pore pressure changes when the groundwater system is stressed. However, numerical groundwater models of underground excavations typically assume constant literature values of Ss. One part of our research program utilised high frequency pore pressure data to evaluate variability and changes in Ss within sedimentary strata overlying a longwall coal mine. Pore pressure data from a vertical series of 6 vibrating wire piezometers (50 to 278 m depth) recording at hourly intervals were compared with barometric pressure data over a period of several years, including data before and during mining. The site was located near the centre of a longwall panel that extracted 3 m of coal at a depth of 330 m. The data was processed to calculate loading efficiency and Ss values by multi-method analyses of barometric and earth tide responses. In situ Ss results varied over one to two orders of magnitude and indicated that Ss changed before and after excavation of underlying coal seams. The vertical leakage of groundwater within the constrained zone ( 10 to 150 m depth) was found to be limited, although some degree of vertical hydraulic connectivity was observed. Depressurization was evident in the fractured zone directly overlying the coal seam, and Ss changes at 250 m depth indicated this confined aquifer may have become unconfined. Our results demonstrate that high frequency pore pressure data can provide realistic Ss values. In situ Ss values were an order of magnitude lower than Ss measured by geomechnical tests of cores, and were significantly different to textbook values set in most local groundwater models. The timing and extent of groundwater level drawdown predicted by models may therefore be underestimated. We have shown, for the first time, that variability of Ss can be significant, and that these changes can provide important insights into how

  13. Assessment of the performance of nasal pillows at high CPAP pressures.

    Science.gov (United States)

    Zhu, Xueling; Wimms, Alison J; Benjafield, Adam V

    2013-09-15

    Compliance with CPAP therapy remains an issue despite its effectiveness. Mask selection is likely to affect a patients experience with CPAP, and multiple mask options are currently available. Nasal pillows have less contact with the face compared to nasal masks and may benefit patients by minimizing side effects; however, they are infrequently used at high CPAP pressures. The aim of this study was to examine the performance of nasal pillows at pressures ≥ 12 cm H2O compared with nasal masks. Twenty-one subjects were recruited. Participants were randomized to Swift FX nasal pillows and their current nasal mask for 7 consecutive nights each in a prospective crossover trial. Objective device data and subjective feedback were collected. There were no differences in objective device data of nasal pillows vs. nasal masks: Daily Usage 7.4 ± 1.4 vs. 7.2 ± 1.4 (h/night); 95(th)%ile Leak 28.6 ± 13.5 vs. 27.9 ± 17.9 (L/min); AHI 1.9 ± 1.3 vs. 1.7 ± 1.1, respectively (all p-values > 0.05). There were no differences between the nasal pillows and nasal masks for subjective ratings of comfort, seal, red marks, side effects such as jetting and dry nose/mouth, and overall performance (all p-values > 0.05). The nasal pillows were rated to be less obtrusive and claustrophobic (both p-values < 0.01), but less stable (p = 0.04). Overall preference was 50% nasal pillows, 45% nasal masks; 5% found no difference. Nasal pillows are as efficacious as nasal masks at CPAP pressures ≥ 12 cm H2O and are a suitable option for patients requiring high CPAP pressures. NIH Clinical Trials Registry. http://clinicaltrials.gov. Nasal Pillows at High CPAP Pressure. Identifier: NCT01690923.

  14. Assessing the Effect of Simultaneous Exposure to Noise and Cigarette Smoke on Workers’ Blood Pressure

    Science.gov (United States)

    Rahimpour, Farzane; Rafiei Manesh, Ehsan; Jarahi, Lida; Eghbali, Saba

    2016-01-01

    Introduction: Noise, as the most common pollutant in the industrial environment, can lead to hearing loss and negatively affect other organs such as the cardiovascular system. Cigarette smoking is a popular habit among some workers, and can also have a negative effect on the cardiovascular system. This study was aimed to investigate the effect of simultaneous exposure to noise and cigarette smoke on the blood pressure of workers at a manufacturing factory. Materials and Methods: This cross-sectional study enrolled 604 workers at a steel factory. Information relating to workers’ demography, employment, and risk factors were recorded. Based on the level of smoking per day, workers exposed to noise fell into one of the four following groups: 1) Non-smokers exposed to noise <85 DB; 2) Smokers exposed to noise <85 DB; 3) Non-smokers exposed to noise ≥85 DB; 4) Smokers exposed to noise ≥85 DB. A t-test, analysis of variance (ANOVA), and logistic regression were applied for analysis using SPSS v11.5. Results: The prevalence of hypertension, cigarette smoking, and exposure to noise ≥85 DB was 11.6%, 15.3%, and 56.4%, respectively, among the workers. The mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 112.3 and 73.9 mmHg, respectively. A significant difference was observed between systolic and diastolic blood pressures in four groups (P=0.001). Posthoc test showed a significant difference between groups 1 and 3 (P=0.001). Regression analysis indicated no significant difference in workers who were simultaneously exposed to noise and cigarette smoke. Conclusion: This study demonstrates that noise is an important factor in terms of hypertension, with no significant differences observed in the prevalence of hypertension between workers who were simultaneously exposed to noise and cigarette smoke. It is suggested that workers’ blood pressure should be regularly monitored in noisy environments. PMID:28008392

  15. Ambulatory assessment of 3D ground reaction force using plantar pressure distribution.

    Science.gov (United States)

    Rouhani, H; Favre, J; Crevoisier, X; Aminian, K

    2010-07-01

    This study aimed to use the plantar pressure insole for estimating the three-dimensional ground reaction force (GRF) as well as the frictional torque (T(F)) during walking. Eleven subjects, six healthy and five patients with ankle disease participated in the study while wearing pressure insoles during several walking trials on a force-plate. The plantar pressure distribution was analyzed and 10 principal components of 24 regional pressure values with the stance time percentage (STP) were considered for GRF and T(F) estimation. Both linear and non-linear approximators were used for estimating the GRF and T(F) based on two learning strategies using intra-subject and inter-subjects data. The RMS error and the correlation coefficient between the approximators and the actual patterns obtained from force-plate were calculated. Our results showed better performance for non-linear approximation especially when the STP was considered as input. The least errors were observed for vertical force (4%) and anterior-posterior force (7.3%), while the medial-lateral force (11.3%) and frictional torque (14.7%) had higher errors. The result obtained for the patients showed higher error; nevertheless, when the data of the same patient were used for learning, the results were improved and in general slight differences with healthy subjects were observed. In conclusion, this study showed that ambulatory pressure insole with data normalization, an optimal choice of inputs and a well-trained nonlinear mapping function can estimate efficiently the three-dimensional ground reaction force and frictional torque in consecutive gait cycle without requiring a force-plate.

  16. The reliability of plantar pressure assessment during barefoot level walking in children aged 7-11 years

    Directory of Open Access Journals (Sweden)

    Cousins Stephen D

    2012-03-01

    Full Text Available Abstract Background Plantar pressure assessment can provide information pertaining to the dynamic loading of the foot, as well as information specific to each region in contact with the ground. There have been few studies which have considered the reliability of plantar pressure data and therefore the purpose of this study was to investigate the reliability of assessing plantar pressure variables in a group of typically developing children, during barefoot level walking. Methods Forty-five participants, aged 7 to 11 years, were recruited from local primary and secondary schools in East London. Data from three walking trials were collected at both an initial and re-test session, taken one week apart, to determine both the within- and between-session reliability of selected plantar pressure variables. The variables of peak pressure, peak force, pressure-time and force-time integrals were extracted for analysis in the following seven regions of the foot; lateral heel, medial heel, midfoot, 1st metatarsophalangeal joint, 2nd-5th metatarsophalangeal joint, hallux and the lesser toes. Reliability of the data were explored using Intra Class Correlation Coefficients (ICC 3,1 and 3,2 and variability with Coefficients of Variation (CoV's. Results The measurements demonstrated moderate to good levels of within-session reliability across all segments of the foot (0.69-0.93, except the lesser toes, which demonstrated poor reliability (0.17-0.50. CoV's across the three repeated trials ranged from 10.12-19.84% for each of the measured variables across all regions of the foot, except the lesser toes which demonstrated the greatest variability within trials (27.15-56.08%. The between-session results demonstrated good levels of reliability across all foot segments (0.79-0.99 except the lesser toes; with moderate levels of reliability reported at this region of the foot (0.58-0.68. The CoV's between-sessions demonstrated that the midfoot (16.41-36.23% and lesser

  17. Translation and testing of the Risk Assessment Pressure Ulcer Sore scale used among residents in Norwegian nursing homes.

    Science.gov (United States)

    Fossum, Mariann; Söderhamn, Olle; Cliffordson, Christina; Söderhamn, Ulrika

    2012-01-01

    The purpose of this study was to translate and test the psychometric properties of the Norwegian-language version of the Risk Assessment Pressure Sore (RAPS) scale. Risk assessment scales for pressure ulcer (PU) prevention have become an aspect of quality improvement in healthcare, but their effectiveness depends on the reliability and validity of the scale.  A convenience sample of 481 residents in 15 nursing homes in rural Norway was included between January and June 2007. The English-language version of the RAPS scale was translated into Norwegian, and this scale was used to collect the data, including a skin examination. The number of PUs and grades were documented. Reliability was assessed in a small group of 26 residents and construct validity in the total study group. Equivalence between two assessments regarding total scores of the RAPS scale was reflected in an intraclass correlation coefficient (ICC) of 0.95. Construct validity was supported, and the RAPS scale could define groups with expected low and high scores. Further evidence of construct validity was shown in a confirmatory factor analysis. The Norwegian version of the RAPS scale has shown sufficient psychometric properties to be considered a reliable and valid scale for identifying risk of PUs among nursing home residents. However, further testing is needed.

  18. Modeling Antarctic Subglacial Lake Filling and Drainage Cycles

    Science.gov (United States)

    Dow, Christine F.; Werder, Mauro A.; Nowicki, Sophie; Walker, Ryan T.

    2016-01-01

    The growth and drainage of active subglacial lakes in Antarctica has previously been inferred from analysis of ice surface altimetry data. We use a subglacial hydrology model applied to a synthetic Antarctic ice stream to examine internal controls on the filling and drainage of subglacial lakes. Our model outputs suggest that the highly constricted subglacial environment of our idealized ice stream, combined with relatively high rates of water flow funneled from a large catchment, can combine to create a system exhibiting slow-moving pressure waves. Over a period of years, the accumulation of water in the ice stream onset region results in a buildup of pressure creating temporary channels, which then evacuate the excess water. This increased flux of water beneath the ice stream drives lake growth. As the water body builds up, it steepens the hydraulic gradient out of the overdeepened lake basin and allows greater flux. Eventually this flux is large enough to melt channels that cause the lake to drain. Lake drainage also depends on the internal hydrological development in the wider system and therefore does not directly correspond to a particular water volume or depth. This creates a highly temporally and spatially variable system, which is of interest for assessing the importance of subglacial lakes in ice stream hydrology and dynamics.

  19. Assessment of the hydrogen external tank pressure decay anomaly on Space Transportation System (STS) 51-L

    Science.gov (United States)

    Buckley, Theresa M.

    1988-01-01

    Following the Challenger tragedy, an evaluation of the integrated main propulsion system flight data revealed a premature decay in the hydrogen external tank ullage pressure. A reconstruction of predicted ullage pressure versus time indicated an inconsistency between predicted and measured ullage pressure starting at approximately 65.5 seconds into the flight and reaching a maximum value between 72 and 72.9 seconds. This discrepancy could have been caused by a hydrogen gas leak or by a liquied hydrogen leak that occurred either in the pressurization system or in the external tank. The corresponding leak rates over the time interval from 65.5 to 72.9 seconds were estimated to range from 0.28 kg/s (0.62 lbm/s) + or - 41 percent to between 0.43 and 0.51kg/s (0.94 and 1.12lbs/s) + or - 1 percent for a gas leak and from 72.9 kg/s (160.5 lbs/s) + or - 41 percent to between 111.6 and 133.2 kg/s (245.8 and 293.3 lbs/s) + or - 1 percent for a liquid leak. No speculation is made to ascertain whether the leak is liquid or gas, as this cannot be determined from the analysis performed. Four structural failures in the hydrogen external tank were considered to explain the leak rates. A break in the 5-cm (2 in) pressurization line, in the 13-cm (5 in) vent line, or in the 43-cm (17 in) feedline is not likely. A break in the 10-cm (4 in) recirculation line with a larger structural failure occurring in the 72 to 73-second time period, the time of the visibly identified premature pressure decay, does seem plausible and the most likely of the four modes considered. These modes are not all-inclusive and do not preclude the possibility of a leak elsewhere in the tank.

  20. Effectiveness and safety of endotracheal tube cuffs filled with air versus filled with alkalinized lidocaine: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Lais Helena Camacho Navarro

    Full Text Available CONTEXT AND OBJECTIVE: High intracuff pressure in endotracheal tubes (ETs may cause tracheal lesions. The aim of this study was to evaluate the effectiveness and safety of endotracheal tube cuffs filled with air or with alkalinized lidocaine. DESIGN AND SETTING: This was a prospective clinical study at the Department of Anesthesiology, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista. METHODS: Among 50 patients, ET cuff pressures were recorded before, 30, 60, 90 and 120 minutes after starting and upon ending nitrous oxide anesthesia. The patients were randomly allocated to two groups: Air, with ET cuff inflated with air to attain a cuff pressure of 20 cmH2O; and Lido, with ET cuff filled with 2% lidocaine plus 8.4% sodium bicarbonate to attain the same pressure. ET discomfort before tracheal extubation, and sore throat, hoarseness and coughing incidence were studied at the time of discharge from the post-anesthesia care unit, and sore throat and hoarseness were studied 24 hours after anesthesia. RESULTS: Pressures in Lido cuffs were significantly lower than in Air cuffs (p < 0.05. Tracheal complaints were similar for the two groups, except for lower ET discomfort and sore throat incidence after 24 hours and lower systolic arterial pressure at the time of extubation in the Lido group (p < 0.05. CONCLUSION: ET cuffs filled with alkalinized lidocaine prevented the occurrence of high cuff pressures during N2O anesthesia and reduced ET discomfort and postoperative sore throat incidence. Thus, alkalinized lidocaine-filled ET cuffs seem to be safer than conventional air-filled ET cuffs.

  1. Response of rocky shore communities to anthropogenic pressures in Albania (Mediterranean Sea): Ecological status assessment through the CARLIT method.

    Science.gov (United States)

    Blanfuné, Aurélie; Boudouresque, Charles François; Verlaque, Marc; Beqiraj, Sajmir; Kashta, Lefter; Nasto, Ina; Ruci, Stela; Thibaut, Thierry

    2016-08-15

    The lower mid-littoral and shallow subtidal communities were studied in the district of Vlora (Albania), three years after the establishment of a Marine Protected Area, with particular attention to the long-lived species. The bioconstructions built in the mid-littoral zone by the calcified rhodobiont Lithophyllum byssoides were in poor condition and sometimes even dead. In contrast, the brown alga Cystoseira amentacea constituted lush stands. For assessing the ecological status of the studied area, the CARLIT method, based upon macroalgal communities, was applied. The observed range of ecological status was wide ('high' through 'bad') and was overall among the lowest assessed to date in the Mediterranean Sea. The occurrence of extensive sea-urchin barren-grounds, though not taken into consideration by the CARLIT index, confirmed the poor condition of large sectors of the study area. Overall, the CARLIT index is well correlated with anthropogenic pressures, as assessed by the LUSI index.

  2. MARKET ASSESSMENT AND TECHNICAL FEASIBILITY STUDY OF PRESSURIZED FLUIDIZED BED COMBUSTION ASH USE

    Energy Technology Data Exchange (ETDEWEB)

    A.E. Bland; T.H. Brown

    1997-04-01

    Western Research Institute, in conjunction with the Electric Power Research Institute, Foster Wheeler International, Inc. and the US Department of Energy, has undertaken a research and demonstration program designed to examine the market potential and the technical feasibility of ash use options for PFBC ashes. Ashes from the Foster Wheeler Energia Oy pilot-scale circulating PFBC tests in Karhula, Finland, combusting (1) low-sulfur subbituminous and (2) high-sulfur bituminous coal, and ash from the AEP's high-sulfur bituminous coal-fired bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing at WR1. The technical feasibility study examined the use of PFBC ash in construction-related applications, including its use as a cementing material in concrete and use in cement manufacturing, fill and embankment materials, soil stabilization agent, and use in synthetic aggregate production. Testing was also conducted to determine the technical feasibility of PFBC ash as a soil amendment for acidic and sodic problem soils and spoils encountered in agricultural and reclamation applications. The results of the technical feasibility testing indicated the following conclusions. PFBC ash does not meet the chemical requirements as a pozzolan for cement replacement. However, it does appear that potential may exist for its use in cement production as a pozzolan and/or as a set retardant. PFBC ash shows relatively high strength development, low expansion, and low permeability properties that make its use in fills and embankments promising. Testing has also indicated that PFBC ash, when mixed with low amounts of lime, develops high strengths, suitable for soil stabilization applications and synthetic aggregate production. Synthetic aggregate produced from PFBC ash is capable of meeting ASTM/AASHTO specifications for many construction applications. The residual calcium carbonate and calcium sulfate in the PFE3C ash has been shown to be of

  3. Randall Selitto pressure algometry for assessment of bone-related pain in rats

    DEFF Research Database (Denmark)

    Falk, S.; Ipsen, D. H.; Appel, C. K.

    2015-01-01

    , and the effect of morphine was investigated. Randall Selitto measures of cancer-induced bone pain were supplemented by von Frey testing, weight-bearing and limb use test. Contribution of cutaneous nociception to Randall Selitto measures were examined by local anaesthesia. Results: Randall Selitto pressure...... and pathological bone pain and compared the outcome with more traditional pain-related behaviour measures. Methods: Randall Selitto pressure algometry was performed over the anteromedial part of the tibia in naïve rats, sham-operated rats, and rats inoculated with MRMT-1 carcinoma cells in the left tibia...... algometry over the tibia resulted in reproducible withdrawal thresholds, which were dose-dependently increased by morphine. Cutaneous nociception did not contribute to Randall Selitto measures. In cancer-bearing animals, compared with sham, significant differences in pain-related behaviours were...

  4. Assessing the influence of mechanical ventilation on blood gases and blood pressure in rattlesnakes

    DEFF Research Database (Denmark)

    Bertelsen, Mads F.; Buchanan, Rasmus; Jensen, Heidi M.

    2015-01-01

    OBJECTIVE: To characterize the impact of mechanical positive pressure ventilation on heart rate (HR), arterial blood pressure, blood gases, lactate, glucose, sodium, potassium and calcium concentrations in rattlesnakes during anesthesia and the subsequent recovery period. STUDY DESIGN: Prospective...... ventilation at a tidal volume of 30 mL kg(-1) at 1 breath every 90 seconds, 5 breaths minute(-1) , or 15 breaths minute(-1) . Arterial blood was collected from indwelling catheters at 30, 40, and 60 minutes and 2, 6, and 24 hours following induction of anesthesia and analyzed for pH, PaO2 , PaCO2...... , and selected variables. Mean arterial blood pressure (MAP) and HR were recorded at 30, 40, 60 minutes and 24 hours. RESULTS: Spontaneous ventilation and 1 breath every 90 seconds resulted in a mild hypercapnia (PaCO2 22.4 ± 4.3 mmHg [3.0 ± 0.6 kPa] and 24.5 ± 1.6 mmHg [3.3 ± 0.2 kPa], respectively), 5 breaths...

  5. Failure assessment of aluminum liner based filament-wound hybrid riser subjected to internal hydrostatic pressure

    Science.gov (United States)

    Dikshit, Vishwesh; Seng, Ong Lin; Maheshwari, Muneesh; Asundi, A.

    2015-03-01

    The present study describes the burst behavior of aluminum liner based prototype filament-wound hybrid riser under internal hydrostatic pressure. The main objective of present study is to developed an internal pressure test rig set-up for filament-wound hybrid riser and investigate the failure modes of filament-wound hybrid riser under internal hydrostatic burst pressure loading. The prototype filament-wound hybrid riser used for burst test consists of an internal aluminum liner and outer composite layer. The carbon-epoxy composites as part of the filament-wound hybrid risers were manufactured with [±55o] lay-up pattern with total composite layer thickness of 1.6 mm using a CNC filament-winding machine. The burst test was monitored by video camera which helps to analyze the failure mechanism of the fractured filament-wound hybrid riser. The Fiber Bragg Grating (FBG) sensor was used to monitor and record the strain changes during burst test of prototype filament-wound hybrid riser. This study shows good improvements in burst strength of filament-wound hybrid riser compared to the monolithic metallic riser. Since, strain measurement using FBG sensors has been testified as a reliable method, we aim to further understand in detail using this technique.

  6. Assessing The Effect Of Pressing Matrix Diameter And Compacting Pressure On Density And Durability Of Pellets

    Directory of Open Access Journals (Sweden)

    Macák Miroslav

    2015-03-01

    Full Text Available Pellets made of biomass for energy purposes can be considered as a significant type of biofuel. The efficiency of biopellets depends upon many factors; therefore, in our paper we have focused our attention on measuring the physical properties of biopellets made from lucerne hay and maize stover. The chemical composition of biomass materials is characterised. Biopellets were made on the hydraulic press and their durability was measured on the own instrument designed according to the ASABE S269.4 standard. As the biomass particle size plays an important role in the process of pellets producing, the particle size distribution was determined. According to our experiments, both pressure and diameter had no effect on the durability of pellets for both materials, especially with the pressure force of 100 MPa and 125 MPa, whereas with increasing the pressure force to 150 MPa for the die diameter 20 mm for both lucerne hay and maize stover, a significant increment occurred in the durability of pellets.

  7. Assessment of Dynamic Flow, Pressure and Geomechanical Behaviour of a CO2 Storage Complex

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Frykman, Peter

    it will be of great environmental concern especially to the ground water and other subsurface resources implying that quantifying pressure changes in CO2 sites is very important for monitoring purposes in order to prevent this phenomenon. Large scale CO2 storage has previously been considered for the Vedsted...... where the brine-fresh water interface resides need to be investigated and quantified through simulation studies as part of site qualification, as overpressure can push brine into the fresh water zone and thereby affecting aquifer performance. In order to estimate the sealing potential and rock...... on resulting permeability of deeply buried shale. The second part of this project is focused on assessing two scenarios including sensitivity of caprock permeability and compressibility on pressure development and transmission to the shallower Chalk Group where the brine-fresh water interface resides due...

  8. Cradle-to-Gate Impact Assessment of a High-Pressure Die-Casting Safety-Relevant Automotive Component

    Science.gov (United States)

    Cecchel, Silvia; Cornacchia, Giovanna; Panvini, Andrea

    2016-09-01

    The mass of automotive components has a direct influence on several aspects of vehicle performance, including both fuel consumption and tailpipe emissions, but the real environmental benefit has to be evaluated considering the entire life of the products with a proper life cycle assessment. In this context, the present paper analyzes the environmental burden connected to the production of a safety-relevant aluminum high-pressure die-casting component for commercial vehicles (a suspension cross-beam) considering all the phases connected to its manufacture. The focus on aluminum high-pressure die casting reflects the current trend of the industry and its high energy consumption. This work shows a new method that deeply analyzes every single step of the component's production through the implementation of a wide database of primary data collected thanks to collaborations of some automotive supplier companies. This energy analysis shows significant environmental benefits of aluminum recycling.

  9. Stability of equilibrium of the body with filling

    Science.gov (United States)

    Dosaev, Marat

    2014-12-01

    The motion of a four-blade axisymmetric vane with fixed point is considered in the constant flow of medium. The vane contains an axisymmetric cavity filled by viscous filling. We assumed that aerodynamic forces have an effect to rotor blades only. The filling interacts with walls of cavity by normal pressure and tangential friction force. We assumed that the tangential friction can be described by resultant couple, moment of which depends linearly on the difference between the angular velocity of body and the fluid vorticity vector. Components of vorticity vector satisfy the modified Helmholtz equations. The mathematical model of motion of mechanical system in question is constructed. Stability of the permanent rotation of vane in medium flow is studied. We consider the stability conditions for of the equilibrium of the symmetry axis. We compared these conditions with stability conditions for autorotation of a body without filling. One can observe the opposition between external aerodynamic load and internal friction.

  10. Thallium-201 myocardial imaging in children with heart disease. Quantitative assessment of right ventricular pressure

    Energy Technology Data Exchange (ETDEWEB)

    Mitomori, Toshihiro; Ono, Yasuo; Kamiya, Tetsuro; Nishimura, Tsunehiko; Kozuka, Takahiro (National Cardiovascular Center, Suita, Osaka (Japan)); Kohata, Tohru; Tanimoto, Takeshi

    1985-02-01

    201-TlCl myocardial imaging studies were performed to evaluate systolic pressure of right ventricle on 107 patients including 89 patients with congenital cardiac disease, patients with primary pulmonary hypertension and 13 patients with history of MCLS with the age range of 2 months to 17 years. The congenital cardiac disease group included 30 patients with tetralogy of Fallot, 8 patients with pulmonary stenosis (included 1 patient with double chambered right ventricle), 20 patients with ventricular septal defect, 10 patients with patent ductus arteriosus, 9 patients with atrial septal defect and 12 patients with complete transposition of great arteries. None of the patients with history of MCLS had coronary involvement. 50 ..mu..Ci/kg of 201-TlCl was infused intravenously and after 15 minutes the images were obtained from 5 directions (anterior, LAO 30, LAO 45, LAO 60 and lateral). The angle was determined to demonstrate the intraventricular septum and ventricular free walls cleary separated. The image of end-diastolic phase was obtained with ECG synchronized gated method from that direction. The ROI (region of interest) was defined as a slice line by drawing two lines perpendicular to the septum and the counts of the left and right ventricular free wall (Cl and Cr) were analyzed to evaluate the pressure of right ventricle. The pressure of ventricles were obtained by cardiac catheterization performed at the same time with myocardial imaging. The ratio of Cl and Cr (Cr/Cl) had good correlation with the ratio of peak systolic pressure of left ventricle and right ventricle (regression equation Y=0.84X + 0.08, r=0.87). In each congenital heart disease group, very good correlation was also demonstrated (Y=1.46X - 0.30, r=0.96 in PS; Y=0.70X0.20, r=0.91 in VSD; Y=0.86X + 0.15, r=0.78 in ASD and Y=0.72X + 0.24, r=0.80 in PDA). Thus 201-TlCl myocardial imaging was useful method to evaluate right ventricular pressure noninvasively in congenital cardiac disease.

  11. Risk Assessment of Physiological Effects of Atmospheric Composition and Pressure in Constellation Vehicles

    Science.gov (United States)

    Scheuring, Richard A.; Conkin, Johnny; Jones, J. A.; Gernhardt, M.

    2007-01-01

    To limit the risk of fire and reduce denitrogenation time to prevent decompression sickness to support frequent extravehicular activities on the Moon, a hypobaric (PB = 414 mmHg) and mildly hypoxic (ppO2 = 132 mmHg, 32% O2 - 68% N2) living environment is considered for the Crew Exploration Vehicle (CEV) and Lunar Surface Access Module (LSAM). With acute change in ppO2 from 145-178 mmHg at standard vehicular operating pressure to less than 125 mmHg at desired lunar surface vehicular operating pressures, there is the possibility that some crewmembers may develop symptoms of Acute Mountain Sickness (AMS). The signs and symptoms of AMS (headache plus nausea, dizziness, fatigue, or sleeplessness), could impact crew health and performance on lunar surface missions. An exhaustive literature review on the topic of the physiological effects of reduced ppO2 and absolute pressure as may contribute to the development of altitude symptoms or AMS was performed. The results of the nine most rigorous studies were collated, analyzed and contents on AMS and hypoxia symptoms summarized. There is evidence for an absolute pressure effect per se on AMS, so the higher the altitude for a given hypoxic alveolar O2 partial pressure (PAO2), the greater the AMS response. About 25% of adults are likely to experience mild AMS near 2,000 m altitude following a rapid ascent from sea level while breathing air (6,500 feet, acute PAO2 = 75 mmHg). The operational experience with the Shuttle staged denitrogenation protocol at 528 mmHg (3,048 m) while breathing 26.5% O2 (acute PAO2 = 85 mmHg) in astronauts adapting to microgravity suggests a similar likely experience in the proposed CEV environment. We believe the risk of mild AMS is greater given a PAO2 of 77 mmHg at 4,876 m altitude while breathing 32% O2 than at 1,828 m altitude while breathing 21% O2. Only susceptible astronauts would develop mild and transient AMS with prolonged exposure to 414 mmHg (4,876 m) while breathing 32% O2 (acute PAO2

  12. Probabilistic fracture mechanics applied for DHC assessment in the cool-down transients for CANDU pressure tubes

    Energy Technology Data Exchange (ETDEWEB)

    Radu, Vasile, E-mail: vasile.radu@nuclear.ro [Institute for Nuclear Research Pitesti, 1st Campului Street, 115400 Mioveni, Arges, P.O. Box 78, Mioveni (Romania); Roth, Maria [Institute for Nuclear Research Pitesti, 1st Campului Street, 115400 Mioveni, Arges, P.O. Box 78, Mioveni (Romania)

    2012-12-15

    For CANDU pressure tubes made from Zr-2.5%Nb alloy, the mechanism called delayed hydride cracking (DHC) is widely recognized as main mechanism responsible for crack initiation and propagation in the pipe wall. Generation of some blunt flaws at the inner pressure tube surface during refueling by fuel bundle bearing pad or by debris fretting, combined with hydrogen/deuterium up-take (20-40 ppm) from normal corrosion process with coolant, may lead to crack initiation and growth. The process is governed by hydrogen hysteresis of terminal solid solubility limits in Zirconium and the diffusion of hydrogen atoms in the stress gradient near to a stress spot (flaw). Creep and irradiation growth under normal operating conditions promote the specific mechanisms for Zirconium alloys, which result in circumferential expansion, accompanied by wall thinning and length increasing. These complicate damage mechanisms in the case of CANDU pressure tubes that are also are affected by irradiation environment in the reactor core. The structural integrity assessment of CANDU fuel channels is based on the technical requirements and methodology stated in the Canadian Standard N285.8. Usually it works with fracture mechanics principles in a deterministic manner. However, there are inherent uncertainties from the in-service inspection, which are associated with those from material properties determination; therefore a necessary conservatism in deterministic evaluation should be used. Probabilistic approach, based on fracture mechanics principle and appropriate limit state functions defined as fracture criteria, appears as a promising complementary way to evaluate structural integrity of CANDU pressure tubes. To perform this, one has to account for the uncertainties that are associated with the main parameters for pressure tube assessment, such as: flaws distribution and sizing, initial hydrogen concentration, fracture toughness, DHC rate and dimensional changes induced by long term

  13. Numerical simulation for thermal flow filling process of casting

    Institute of Scientific and Technical Information of China (English)

    CHEN Ye; ZHAO Yu-hong; HOU Hua

    2006-01-01

    The solution algorithm (SOLA) method was used to solve the velocity and pressure field of the thermal flow filling process, and the volume of fluid (VOF) method for the free surface problem. Since the "donor-acceptor" rule often results in the free interface vague, the explicit difference method was adopted, and a method describing the free surface state at 0<F<1 was proposed to deal with this problem. In order to raise the computation efficiency, such algorithms were investigated and invalidated as: 1) internal and external area separation simplification algorithm; 2) the reducing necessary search area method. With the improved algorithms, the filling processes of the valve cover castings with gravity cast and an up cylinder block casting with low-pressure cast were simulated, the simulation results are believable and the computation efficiency is greatly improved. The SOLA-VOF model and its difference method for thermal fluid flow filling process were introduced.

  14. The Effects of Iron Filling On Some Mechanical and Physical ...

    African Journals Online (AJOL)

    acer

    concentration, hot pressing temperature of 160°C, applied pressure of 10 tons equivalent to 12.5Mpa, ... condition as those of the sawdust- iron filling particleboard. ... maximum effect. This action .... were weighed in the weighing balance and it.

  15. Process and part filling control in micro injection molding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Schoth, Andreas

    2008-01-01

    The influence of process parameters on μ-injection molding (μIM) and on μ-injection molded parts has been investigated using Design of Experiments. A mold with a sensor applied at injection location was used to monitor actual injection pressure and to determine the cavity filling time. Flow markers...

  16. Radial artery applanation tonometry for continuous non-invasive arterial pressure monitoring in intensive care unit patients: comparison with invasively assessed radial arterial pressure.

    Science.gov (United States)

    Meidert, A S; Huber, W; Müller, J N; Schöfthaler, M; Hapfelmeier, A; Langwieser, N; Wagner, J Y; Eyer, F; Schmid, R M; Saugel, B

    2014-03-01

    Radial artery applanation tonometry technology can be used for continuous non-invasive measurement of arterial pressure (AP). The purpose of this study was to evaluate this AP monitoring technology in intensive care unit (ICU) patients in comparison with invasive AP monitoring using a radial arterial catheter. In 24 ICU patients (German university hospital), AP values were simultaneously recorded on a beat-to-beat basis using radial artery applanation tonometry (T-Line system; Tensys Medical, San Diego, CA, USA) and a radial arterial catheter (contralateral arm). The primary endpoint of the study was to investigate the accuracy and precision of the non-invasively assessed AP measurements with the Bland-Altman method based on averaged 10 beat AP epochs (n=2993 10 beat epochs). For mean AP (MAP), systolic AP (SAP), and diastolic AP (DAP), we observed a bias (±standard deviation of the bias; 95% limits of agreement; percentage error) of +2 mm Hg (±6; -11 to +15 mm Hg; 15%), -3 mm Hg (±15; -33 to +27 mm Hg; 23%), and +5 mm Hg (±7; -9 to +19 mm Hg; 22%), respectively. In ICU patients, MAP and DAP measurements obtained using radial artery applanation tonometry show clinically acceptable agreement with invasive AP determination with a radial arterial catheter. While the radial artery applanation tonometry technology also allows SAP measurements with high accuracy, its precision for SAP measurements needs to be further improved.

  17. Improved Assessment Strategies for Vapor Intrusion Passive Samplers and Building Pressure Control

    Science.gov (United States)

    2013-09-01

    Long-Term Monitoring of Soil Vapor Intrusion to Indoor Air Using Quantitative Passive Diffusive- Adsorptive Sampling Techniques,” Mr. Todd McAlary is...on Henry’s Law Constant as >1 × 10-5 atm-m3 mol-1 and a vapor pressure >1 mm Hg Pathway Screening Criteria: For sites with volatile chemicals in...Term Monitoring of Soil Vapor Intrusion to Indoor Air Using Quantitative Passive Diffusive- Adsorptive Sampling Techniques.” The focus of the

  18. Association between pressure pain sensitivity and autonomic function as assessed by a tilt table test

    DEFF Research Database (Denmark)

    Ballegaard, Søren; Bergmann, Natasha; Karpatschof, Benny;

    2015-01-01

    blood pressure (SBP) and heart rate (HR) responses to TTT; and (2) to test the hypothesis that a reduction of resting PPS raises the PPS, SBP and HR responses to TTT response and lowers risk factors for ANS dysfunction (ANSD). METHODS: Cross-sectional study: In 361 patients with stable ischemic heart...... disease we measured PPS, SBP, and HR during TTT. Intervention study: We reassessed subjects with persistent stress who concluded a stress intervention trial by a second TTT. RESULTS: Cross-sectional study: Resting PPS and the PPS response to TTT were correlated (r = - 0.37). The PPS response to TTT...

  19. Determinação de volumes e pressões de balonetes de tubos traqueais insuflados com ar ambiente ou óxido nitroso Determinación de volúmenes y presiones de balones de tubos traqueales insuflados con aire ambiente u óxido nitroso Volume and pressure of tracheal tube cuffs filled with air or nitrous oxide

    Directory of Open Access Journals (Sweden)

    Ernesto Leonardo Cárpio Peña

    2004-06-01

    balanceada con entubación orotraqueal. El balón fue insuflado conforme criterios clínicos. Las medidas de base fueron realizadas después de 15 minutos del inicio de la anestesia con un manómetro aneróide calibrado en cm de H2O y dieron los valores iniciales de presión y volumen. Los pacientes fueron divididos en dos grupos: balón reinsuflado con aire ambiente, grupo A, o con óxido nitroso, grupo B. Las medidas de presión fueron obtenidas en intervalos hasta la primera hora y los resultados comparados. RESULTADOS: Los grupos se mostraron comparables para edad y sexo. En ambos grupos los valores basales medios para presión fueron próximos de 40 cmH2O con 8 ml de volumen. En el grupo con aire ambiente, las presiones aumentaron hasta 36 cmH2O en una hora. En el grupo de balón insuflado con N2O, las presiones cayeron abajo de 20 cmH2O entre 20 y 30 minutos de anestesia. CONCLUSIONES: El uso de N2O a 100% para insuflación del balón de sonda traqueal no constituye método seguro, acarreando progresiva pérdida de la capacidad de vedación. El uso de aire ambiente promueve aumento de volumen y de presión en el balón, aumentando la posibilidad de lesión de la mucosa traqueal.BACKGROUND AND OBJECTIVES: Tracheal tube cuff pressure against tracheal wall should to prevent air leaked or pulmonary aspiration, allowing adequate capillary blood flow. This study aimed at determining pressure variations of tracheal tube cuffs filled with air or 100% nitrous oxide. METHODS: Participated in this study 30 patients submitted to balanced general anesthesia with tracheal intubation. Cuff was inflated according to clinical criteria. The intracuff pressure measurements were undertaken after 15 minutes of anesthesia by means of an aneroid manometer gaged in cm of H2O and have provided initial pressure and volume values. The patients was allocated in two groups: cuff inflated with air, group A, and with nitrous oxide, group B. Measurements were recorded during one hour and results were

  20. Mechanism and application of a newly developed pressure casting process: horizontal squeeze casting

    Directory of Open Access Journals (Sweden)

    Li Peijie

    2014-07-01

    Full Text Available Compared to traditional high-pressure die casting (HPDC, horizontal squeeze casting (HSC is a more promising way to fabricate high-integrity castings, owing to a reduced number of gas and shrinkage porosities produced in the casting. In this paper, the differences between HSC and HPDC are assessed, through which it is shown that the cavity filling velocity and the size of the gating system to be the most notable differences. Equipment development and related applications are also reviewed. Furthermore, numerical simulation is used to analyze the three fundamental characteristics of HSC: slow cavity filling, squeeze feeding and slow sleeve filling. From this, a selection principle is given based on the three related critical casting parameters: cavity filling velocity, gate size and sleeve filling velocity. Finally, two specific applications of HSC are introduced, and the future direction of HSC development is discussed.

  1. At what age group blood pressure discontinue to increase? An assessment using change-point analysis

    Directory of Open Access Journals (Sweden)

    Khalib A. Latiff

    2010-05-01

    Full Text Available Aim To study at what age group blood pressure ceases to increase for women and men.Methods Applying change-point technique, we used our existing database - mega base-line cross-sectional Hulu Langat Health Study that was initiated in 2000 - to locate the most appropriate age limit in planning promotive, preventive and controlling strategies against systolic hypertension.Results Systolic hypertension was found to be constantly increasing for both gender right from the early age until the middle age group. However, women achieved the systolic peak 15 years earlier (at 41-45 years old than men (at 56-60 years old. Systolic blood pressure was steadily declined after the peak.Conclusions Hypertension intervention, we recommend age before 40 (women and 55 (men be the most appropriate period to apply various public health intervention, after that, the action must be exclusively curative. (Med J Indones 2010; 19:136-41Keywords: change-point analysis, public health intervention, systolic hypertension

  2. The Camino intracranial pressure device in clinical practice. Assessment in a 1000 cases.

    Science.gov (United States)

    Gelabert-González, M; Ginesta-Galan, V; Sernamito-García, R; Allut, A G; Bandin-Diéguez, J; Rumbo, R M

    2006-04-01

    Intracranial pressure (ICP) monitoring has become standard in the management of neurocritical patients. A variety of monitoring techniques and devices are available, each offering advantages and disadvantages. Analysis of large populations has never been performed. A prospective study was designed to evaluate the Camino fiberoptic intraparenchymal cerebral pressure monitor for complications and accuracy. Between 1992-2004 one thousand consecutive patients had a fiberoptic ICP monitor placed. The most frequent indication for monitoring was severe head injury (697 cases). The average duration of ICP monitoring was 184.6 +/- 94.3 hours; the range was 16-581 hours. Zero drift (range, -17 to 21 mm Hg; mean 7.3 +/- 5.1) was recorded after the devices were removed from 624 patients. Mechanical complications such as: breakage of the optical fiber (n = 17); dislocations of the fixation screw (n = 15) or the probe (n = 13); and failure of ICP recording for unknown reasons (n = 4) were found in 49 Camino devices. The Camino ICP sensor remains one of the most popular ICP monitoring devices for use in critical neurosurgical patients. The system offers reliable ICP measurements in an acceptable percentage of device complications and the advantage of in vivo recalibration. The incidence of technical complications was low and similar to others devices.

  3. Pressure Flow Analysis in the Assessment of Preswallow Pharyngeal Bolus Presence in Dysphagia

    Directory of Open Access Journals (Sweden)

    Lara Ferris

    2015-01-01

    Full Text Available Objectives. Preswallow pharyngeal bolus presence is evident in patients with oropharyngeal dysphagia. Pressure flow analysis (PFA using high resolution manometry with impedance (HRMI with AIMplot software is a method for objective interpretation of pharyngeal and upper esophageal sphincter (UES pressures and bolus flow patterns during swallowing. This study aimed to observe alterations in PFA metrics in the event of preswallow pharyngeal bolus presence as seen on videofluoroscopy (VFSS. Methods. Swallows from 40 broad dysphagia patients and 8 controls were recorded with a HRMI catheter during simultaneous VFSS. Evidence of bolus presence and level reached prior to pharyngeal swallow onset was recorded. AIMPlot software derived automated PFA functional metrics. Results. Patients with bolus movement to the pyriform sinuses had a higher SRI, indicating greater swallow dysfunction. Amongst individual metrics, TNadImp to PeakP was shorter and flow interval longer in patient groups compared to controls. A higher pharyngeal mean impedance and UES mean impedance differentiated the two patient groups. Conclusions. This pilot study identifies specific altered PFA metrics in patients demonstrating preswallow pharyngeal bolus presence to the pyriform sinuses. PFA metrics may be used to guide diagnosis and treatment of patients with oropharyngeal dysphagia and track changes in swallow function over time.

  4. The pipeline fracture behavior and pressure assessment under HIC (Hydrogen induced cracking) environment

    Energy Technology Data Exchange (ETDEWEB)

    Shaohua, Dong [China National Petroleum Corporation (CNPC), Beijing (China); Lianwei, Wang [University of Science and Technology Beijing (USTB), Beijing (China)

    2009-07-01

    As Hydrogen's transmit and diffuse, after gestating for a while, the density of hydrogen around crack tip of pipeline will get to the critical density, and the pipeline material will descend, make critical stress factor, the reason of pipeline Hydrogen Induced Cracking is Hydrogen's transmit and diffuse. The stress factor of Hydrogen Induced Cracking under surroundings-condition of stress is the key that estimate material's rupture behavior. The paper study the relationship among hydrogen concentrate, crack tip stress, stain field, hydrogen diffusion and inner pressure for crack tip process zone, then determined the length of HIC (hydrogen induced cracking) process zone. Based on the theory of propagation which reason micro-crack making core, dislocation model is produced for fracture criteria of HIC, the influence between material and environments under the HIC is analyzed, step by step pipeline maximum load pressure and threshold of J-integrity ( J{sub ISCC} ) is calculated, which is very significant for pipeline safety operation. (author)

  5. Paleovalley fills: Trunk vs. tributary

    Science.gov (United States)

    Kvale, E.P.; Archer, A.W.

    2007-01-01

    A late Mississippian-early Pennsylvanian eustatic sea level drop resulted in a complex lowstand drainage network being eroded across the Illinois Basin in the eastern United States. This drainage system was filled during the early part of the Pennsylvanian. Distinct differences can be recognized between the trunk and tributary paleovalley fills. Fills preserved within the trunk systems tend to be fluvially dominated and consist of bed-load deposits of coarse- to medium-grained sandstone and conglomerate. Conversely, the incised valleys of tributary systems tend to be filled with dark mudstone, thinly interbedded sandstones, and mudstones and siltstones. These finer grained facies exhibit marine influences manifested by tidal rhythmites, certain traces fossils, and macro- and microfauna. Examples of tributary and trunk systems, separated by no more than 7 km (4.3 mi) along strike, exhibit these styles of highly contrasting fills. Useful analogs for understanding this Pennsylvanian system include the Quaternary glacial sluiceways present in the lower Ohio, White, and Wabash river valleys of Indiana (United States) and the modern Amazon River (Brazil). Both the Amazon River and the Quaternary rivers of Indiana have (or had) trunk rivers that are (were) dominated by large quantities of bed load relative to their tributaries. The trunk valley systems of these analogs aggraded much more rapidly than their tributary valleys, which evolved into lakes because depositional rates along the trunk are (were) so high that the mouths of the tributaries have been dammed by bed-load deposits. These Holocene systems illustrate that sediment yields can significantly influence the nature of fill successions within incised valleys independent of rates of sea level changes or proximity to highstand coastlines. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  6. Indication for shunt operation of normal pressure hydrocephalus. Combined assessment of infusion test and dynamic CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Jinnai, Takahiro; Nagao, Seigo [Kagawa Medical Univ., Miki (Japan); Kuyama, Hideyuki

    2000-03-01

    Normal pressure hydrocephalus (NPH) is one of the diseases that causes a neuro-surgically treatable form of dementia. Although patients with NPH can be treated with shunt operation, reliable indications for the surgery are not yet established. In this study, 20 NPH patients diagnosed by clinical symptoms were subjected to combined assessment by infusion test and dynamic CT scan, a useful diagnostic tool to select a shunt responsive cases. Patients were evaluated by measuring sequential changes in the density of the periventricular lucency (PVL) using dynamic CT scan and continuous lumbar subdural pressure monitoring during an infusion manometric test at a rate of 0.8 ml/min for 30 min. The average lumbar subdural pressure during infusion manometric test in the shunt responsive group was 18.4{+-}5.8 mmHg, which was significantly higher than that in the shunt non-responsive group which was 10.0{+-}4.0 mmHg (p<0.01). The relative changes in PVL density in the dynamic CT was also significantly higher in the shunt responsive group (0.99{+-}0.61 HU) compared to the shunt non-responsive group (0.15{+-}0.32) (p<0.01). Dynamic CT scan with infusion manometric test is useful in the selection of patients with NPH who are likely to respond to shunt surgery. (author)

  7. Changing the "Normal Range" for Blood Pressure from 140/90 to 130/Any Improves Risk Assessment.

    Science.gov (United States)

    Fulks, Michael; Stout, Robert L; Dolan, Vera F

    2015-01-01

    Objective .- Redefine the "normal" reference range for blood pressure from <140/90 to one that more effectively identifies individuals with increased mortality risk. Method .- Data from the recently published 2014 CRL blood pressure study was used. It includes 2,472,706 life insurance applicants tested by Clinical Reference Laboratory from 1993 to 2007 with follow-up for vital status using the September 2011 Social Security Death Master File. Various upper limits of blood pressure (BP in mm Hg) were evaluated to determine if any was superior to the current, commonly used limit of 140/90 in identifying individuals with increased mortality risk. Results .- An alternative reference range using a systolic BP (SBP) <130 with any diastolic BP (DBP) included 84% of life insurance applicants. It had a lower mortality rate and narrower range of relative risk than <140/90, including 89% as many applicants but only 68% as many deaths. This pattern of lives and deaths was consistent across age and sex. Conclusion .- Switching to a "normal" reference range of SBP <130 offers superior risk assessment relative to using BP <140/90 while still including a sufficient percentage of the population.

  8. Assessment of Plasmodium falciparum resistance to ferroquine (SSR97193 in field isolates and in W2 strain under pressure

    Directory of Open Access Journals (Sweden)

    Pradines Bruno

    2006-02-01

    Full Text Available Abstract Background Ferroquine (FQ, or SSR97193, is a novel antimalarial drug currently in phase I clinical trials. FQ is a unique organometallic compound designed to overcome the chloroquine (CQ resistance problem. FQ revealed to be equally active on CQ-sensitive and CQ-resistant Plasmodium falciparum laboratory strains and field isolates. FQ is also curative on rodent malaria parasites. As FQ will be tested in patients, the potential for resistance to this drug was evaluated. Methods The relationship between CQ-resistant transporter gene genotype and susceptibility to FQ were studied in 33 Cambodian P. falciparum field isolates previously studied for their in vitro response to CQ. In parallel, the ability of the CQ-resistant strain W2, to become resistant to FQ under drug pressure was assessed. Results The IC50 values for FQ in field isolates were found to be unrelated to mutations occurring in the P. falciparum chloroquine resistance transporter (PfCRT or to the level of expression of the corresponding mRNA. In vitro, under a drug pressure of 100 nM of FQ, transient survival was observed in only one of two experiments. Conclusion Field isolates studies and experimental drug pressure experiments showed that FQ overcomes CQ resistance, which reinforces the potential of this compound as a new antimalarial drug.

  9. Modeling Antarctic subglacial lake filling and drainage cycles

    Directory of Open Access Journals (Sweden)

    C. F. Dow

    2015-11-01

    Full Text Available The growth and drainage of active subglacial lakes in Antarctica has previously been inferred from analysis of ice surface altimetry data. We use a subglacial hydrology model applied to a synthetic Antarctic ice stream to determine internal controls on the filling and drainage of subglacial lakes and their impact on ice stream dynamics. Our model outputs suggest that the highly constricted subglacial environment of the ice stream, combined with relatively high rates of water flow funneled from large catchments, can combine to create a system exhibiting slow-moving pressure waves. Over a period of years, the accumulation of water in the ice stream onset region results in a buildup of pressure creating temporary channels, which then evacuate the excess water. This increased flux of water through the ice stream drives lake growth. As the water body builds up, it too steepens the hydraulic gradient and allows greater flux out of the overdeepened lake basin. Eventually this flux is large enough to create channels that cause the lake to drain. Due to the presence of the channels, the drainage of the lake causes high water pressures around 50 km downstream of the lake rather than immediately in the vicinity of the overdeepening. Following lake drainage, channels again shut down. Lake drainage depends on the internal hydrological development in the wider system and therefore does not directly correspond to a particular water volume or depth. This creates a highly temporally and spatially variable system, which is of interest for assessing the importance of subglacial lakes in ice stream hydrology and dynamics.

  10. QENS investigation of filled rubbers

    Energy Technology Data Exchange (ETDEWEB)

    Triolo, A.; Lechner, R.E.; Desmedt, A.; Pieper, J. [CNR - Istituto per i Processi Chimico-Fisici, sez. Messina, Via La Farina 237, 98123 Messina (Italy); Lo Celso, F.; Triolo, R. [Dip. Chimica Fisica, V. le delle Scienze, Parco d' Orleans, Padiglione 17, Universita di Palermo, 90128 Palermo (Italy); Negroni, F. [Pirelli Pneumatici S.p.A, V. le Sarca 222, 20126 Milano (Italy); Arrighi, V.; Qian, H. [Chemistry School of Engineering and Physical Sciences, Heriot-Watt University, EH14 4AS Edinburgh (United Kingdom); Frick, B. [Institut Laue-Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble, Cedex 9 (France)

    2002-07-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  11. QENS investigation of filled rubbers

    CERN Document Server

    Triolo, A; Desmedt, A; Pieper, J K; Lo Celso, F; Triolo, R; Negroni, F; Arrighi, V; Qian, H; Frick, B

    2002-01-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  12. QENS investigation of filled rubbers

    Science.gov (United States)

    Triolo, A.; Lo Celso, F.; Negroni, F.; Arrighi, V.; Qian, H.; Lechner, R. E.; Desmedt, A.; Pieper, J.; Frick, B.; Triolo, R.

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface.

  13. Gas-Filled Capillary Model

    Science.gov (United States)

    Steinhauer, L. C.; Kimura, W. D.

    2006-11-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.

  14. Use of digital images in the assessment and treatment of pressure ulcers in patients with spinal injuries in community settings.

    Science.gov (United States)

    Sarhan, Firas; Weatherburn, Gwyn; Graham, Allison; Thiyagarajan, Chinnaya

    2010-01-01

    We conducted a retrospective review of the digital images in the clinical records of 50 patients with pressure ulcers. Ten nurses independently assessed one image from each patient. There was a total of 414 responses from the nurses about the stage and location of the ulcers (83% response rate). The average agreement about the stage and location of the ulcers was 85%. The overall agreement declined as the stage of the ulcer increased. The average agreement regarding the wound descriptors was: necrosis 85%, granulation tissue 81%, ischaemia 83%, cellulitis /infection 69%, erythema 68%. Almost all nurses felt the need to change the current management of the wound (460 responses, or 92%). The nurses judged that most digital images were of good quality (17%) or very good quality (79%). The present study suggests that a high percentage of assessments for patients currently travelling to specialist clinics could be performed in the community using digital images and telemedicine.

  15. Introducing Contactless Blood Pressure Assessment Using a High Speed Video Camera.

    Science.gov (United States)

    Jeong, In Cheol; Finkelstein, Joseph

    2016-04-01

    Recent studies demonstrated that blood pressure (BP) can be estimated using pulse transit time (PTT). For PTT calculation, photoplethysmogram (PPG) is usually used to detect a time lag in pulse wave propagation which is correlated with BP. Until now, PTT and PPG were registered using a set of body-worn sensors. In this study a new methodology is introduced allowing contactless registration of PTT and PPG using high speed camera resulting in corresponding image-based PTT (iPTT) and image-based PPG (iPPG) generation. The iPTT value can be potentially utilized for blood pressure estimation however extent of correlation between iPTT and BP is unknown. The goal of this preliminary feasibility study was to introduce the methodology for contactless generation of iPPG and iPTT and to make initial estimation of the extent of correlation between iPTT and BP "in vivo." A short cycling exercise was used to generate BP changes in healthy adult volunteers in three consecutive visits. BP was measured by a verified BP monitor simultaneously with iPTT registration at three exercise points: rest, exercise peak, and recovery. iPPG was simultaneously registered at two body locations during the exercise using high speed camera at 420 frames per second. iPTT was calculated as a time lag between pulse waves obtained as two iPPG's registered from simultaneous recoding of head and palm areas. The average inter-person correlation between PTT and iPTT was 0.85 ± 0.08. The range of inter-person correlations between PTT and iPTT was from 0.70 to 0.95 (p high speed camera can be potentially utilized for unobtrusive contactless monitoring of abrupt blood pressure changes in a variety of settings. The initial prototype system was able to successfully generate approximation of pulse transit time and showed high intra-individual correlation between iPTT and BP. Further investigation of the proposed approach is warranted.

  16. Global buckling assessment of high pressure and high temperature (HP/HT) offshore pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung-Ho; Jung, Jong-Jin; Lee, Woo-Seob [Maritime Research Institute, Hyundai Heavy Industries, Ulsan, (Korea, Republic of); Kim, Yun-Hak; Kim, Jong-Bae [Offshore Installation Engineering Department, Hyundai Heavy Industries, Ulsan, (Korea, Republic of)

    2010-07-01

    High pressure and high temperature (HP/HT) offshore pipelines are frequently subjected to lateral buckling due to excessive compressive axial force. Several control processes have been designed such as sleepers to reduce lateral buckling. This paper investigated the effect of the introduction of sleepers as buckle triggers on the behavior of HP/HT pipelines. A 3D finite element analysis using ABAQUS software was performed to simulate concrete sleepers and a profile of the seabed. The analysis criteria were the buckling amplitude, Von Mises stress, equivalent plastic strain and the effective axial force on the pipeline. A case study for HP/HT pipeline was been carried out based on installation surveys. Comparisons between the results from a model without buckle trigger and those from a model with buckle trigger were carried out. It was found that the change to the support structure, adding a buckle trigger, affected the behaviour of the pipeline considerably.

  17. Advanced Examination Techniques Applied to the Assessment of Vacuum Pressure Impregnation (VPI) of ITER Correction Coils

    CERN Document Server

    Sgobba, Stefano; Samain, Valerie; Libeyre, Paul; Cecillon, Alexandre; Dawid, J

    2014-01-01

    The ITER Magnet System includes a set of 18 superconducting correction coils (CC) which are used to compensate the error field modes arising from geometrical deviations caused by manufacturing and assembly tolerances. The turn and ground insulation are electrically insulated with a multi-layer fiberglass polyimide interleaved composite, impregnated with epoxy resin using vacuum pressure impregnation (VPI). Adequate high voltage insulation (5 kV), mechanical strength and rigidity of the winding pack should be achieved after impregnation and curing of the insulation system. VPI is an effective process to avoid defects such dry spots and incomplete wet out. This insulation technology has also been developed since several years for application to large superconducting coils and more recently to ITER CC. It allows the coils to be impregnated without impacting on their functional characteristics. One of the critical challenges associated with the construction of the CC is the qualification of the VPI insulation. Se...

  18. Probabilistic integrity assessment of CANDU pressure tube for the consideration of flaw generation time

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Sang Log; Kim, Young Jin [Sungkyunkwan Univ., Seoul (Korea, Republic of); Lee, Joon Seong [Kyonggi Univ., Seoul (Korea, Republic of); Park, Youn Won [KINS, Taejon (Korea, Republic of)

    2001-07-01

    This paper describes a Probabilistic Fracture Mechanics (PFM) analysis based on Monte Carlo (MC) simulation. In the analysis of CANDU pressure tube, it is necessary to perform the PFM analyses based on statistical consideration of flaw generation time. A depth and an aspect ratio of initial semi-elliptical surface crack, a fracture toughness value, Delayed Hydride Cracking (DHC) velocity, and flaw generation time are assumed to be probabilistic variables. In all the analyses, degradation of fracture toughness due to neutron irradiation is considered. Also, the failure criteria considered are plastic collapse, unstable fracture and crack penetration. For the crack growth by DHC, the failure probability was evaluated in due consideration of flaw generation time.

  19. Abdominal Twin Pressure Sensors for the assessment of abdominal injuries in Q dummies: in-dummy evaluation and performance in accident reconstructions.

    Science.gov (United States)

    Beillas, Philippe; Alonzo, François; Chevalier, Marie-Christine; Lesire, Philippe; Leopold, Franck; Trosseille, Xavier; Johannsen, Heiko

    2012-10-01

    The Abdominal Pressure Twin Sensors (APTS) for Q3 and Q6 dummies are composed of soft polyurethane bladders filled with fluid and equipped with pressure sensors. Implanted within the abdominal insert of child dummies, they can be used to detect abdominal loading due to the belt during frontal collisions. In the present study - which is part of the EC funded CASPER project - two versions of APTS (V1 and V2) were evaluated in abdominal belt compression tests, torso flexion test (V1 only) and two series of sled tests with degraded restraint conditions. The results suggest that the two versions have similar responses, and that the pressure sensitivity to torso flexion is limited. The APTS ability to detect abdominal loading in sled tests was also confirmed, with peak pressures typically below 1 bar when the belt loaded only the pelvis and the thorax (appropriate restraint) and values above that level when the abdomen was loaded directly (inappropriate restraint). Then, accident reconstructions performed as part of CASPER and previous EC funded projects were reanalyzed. Selected data from 19 dummies (12 Q6 and 7 Q3) were used to plot injury risk curves. Maximum pressure, maximum pressure rate and their product were all found to be injury predictors. Maximum pressure levels for a 50% risk of AIS3+ were consistent with the levels separating appropriate and inappropriate restraint in the sled tests (e.g. 50% risk of AIS3+ at 1.09 bar for pressure filtered CFC180). Further work is needed to refine the scaling techniques between ages and confirm the risk curves.

  20. Application of Master Curve fracture toughness for reactor pressure vessel integrity assessment in the USA

    Energy Technology Data Exchange (ETDEWEB)

    Server, William; Rosinski, Stan; Lott, Randy; Kim, Charles; Weakland, Dennis

    2002-08-01

    The Master Curve fracture toughness approach has been used in the USA for better defining the transition temperature fracture toughness of irradiated reactor pressure vessel (RPV) steels for end-of-life (EOL) and EOL extension (EOLE) time periods. The first application was for the Kewaunee plant in which the life-limiting material was a circumferential weld metal. Fracture toughness testing of this weld metal corresponding to EOL and beyond EOLE was used to reassess the PTS screening value, RT{sub PTS}, and to develop new operating pressure-temperature curves. The NRC has approved this application using a shift-based methodology and higher safety margins than those proposed by the utility and its contractors. Beaver Valley Unit 1, a First Energy nuclear plant, has performed similar fracture toughness testing, but none of the testing has been conducted at EOL or EOLE at this time. Therefore, extrapolation of the life-limiting plate data to higher fluences is necessary, and the projections will be checked in the next decade by Master Curve fracture toughness testing of all of the Beaver Valley Unit 1 beltline materials (three plates and three welds) at fluences near or greater than EOLE. A supplemental surveillance capsule has been installed in the sister plant, Beaver Valley Unit 2, which has the capability of achieving a higher lead factor while operating under essentially the same environment. The Beaver Valley Unit 1 evaluation has been submitted to the NRC. This paper reviews the shift-based approach taken for the Beaver Valley Unit 1 RPV and presents the use of the RT{sub T{sub 0}} methodology (which evolved out of the Master Curve testing and endorsed through two ASME Code Cases). The applied margin accounts for uncertainties in the various material parameters. Discussion of a direct measurement of RT{sub T{sub 0}} approach, as originally submitted for the Kewaunee case, is also presented.

  1. CNES super pressure balloons assessment and new developments to prepare Strateole-2 campaign

    Science.gov (United States)

    Venel, Stephanie; Spel, Martin; Cocquerez, Philippe; Meyer, Jean-Renaud; Nicot, Jean-Marc.; Parot, Gael; Perraud, Sophie

    The French Space Agency, CNES, has developed, since about twelve years ago, super pressure balloons (SPB) that float on constant density (isopycnic) surfaces in the lowermost stratosphere, carrying 40 to 50 kg payloads, during typically three months. These SPB have been successfully deployed in flotilla of about 20 balloons for different scientific campaigns all over the world in different configuration sizes from 8,5 to 12 m diameter, mainly to document the chemistry and dynamics of the atmosphere, to study gravity waves, and to provide in-situ atmospheric profiles thanks to the NCAR driftsonde payloada. This paper will describe the main results and lessons achieved during the last CONCORDIASI campaign in 2010 over the Antarctic region. Thus, anomalies on the on-board system were investigated and explained by the effect of atmospheric particles fluxes. Also related to these flights, an accurate thermal model was built to evaluate the temperature distribution in the balloon, and several ageing tests have been made to better understand the effect of solar exposure on the different balloon materials. This paper will also present the new developments in progress for the future STRATEOLE-2 campaign dedicated to advance the knowledge of coupling processes between the troposphere and the stratosphere in the deep tropics, and foreseen in 2018-2019. In particular, a new command-control system will be developed to be in conformity with the CNES safety rules, and in continuation with the new zero pressure balloons system named NOSYCA. New solar panels are under investigation. Finally, two new balloon sizes will grow the SPB family to respond to the scientist demand of two special altitude densities.

  2. [A double blind randomised clinical trial to assess the efficacy of the treatments of the superficial pressure sores].

    Science.gov (United States)

    Di Giulio, Paola; Saiani, Luisa; Laquintana, Dario; Palese, Alvisa; Perli, Serena; Andreatta, Mariarosa; Rosa, Federica; Chini, Patrizia; Soraperra, Francesca; Ventura, Ida; Suriani, Cinzia; Romani, Silvia; Zancarli, Miriam; Martini, Marta; Partel, Francesca; Bassetti, Serena; Kaisermann, Rita; Bortolotti, Chiara; Gianordoli, Mirta; Rizzoli, Ilaria; Nardelli, Roberta; Pellizzari, Enrico; Valduga, Edda; Castaman, Marta; Pordenon, Marta; Beltrame, Moira; Bertolo, Cecilia; Casasola, Eleonora; Del Pin, Patrizia; Giolo, Simonetta; Marcatti, Emanuele; Pecini, Dina; Rodaro, Marisa; Zanon, Cristina; Stefanon, Laura; Covre, Lidia; Babbo, Consuela; Martin, Irma; Roilo, Antonia; Zanutel, Marta; Sabbadin, Silvano; Boin, Laura; Caron, Alessia; Martignago, Egidio; Venturin, Valter; Greggio, Annalisa; Frigo, Paola; Lazzaron, Daniela; Tonietto, Annalisa; Zanin, Barbara; Zorzi, Silvano; Zuanon, Antonio; Salmaso, Daniele; Frison, Tiziana; Marin, Irene; Buosi, Antonella; Fiorese, Elena; Gasparin, Dino; Goat, Barbara; Saccardo, Graziella; Simonetto, Ornella; Gomiero, Silvio; Baccara, Nicoletta; Ghirardello, Lucia; Niolu, Marilena; Silvestri, Sabrina; Buffon, Maria Luisa; Casson, Paola; Santantonio, Rosy; Albore, Piersandro; Mazzorana, Elvira; Terziariol, Laura; Bulgarelli, Giuliana; Barani, Elisa; Gasparini, Patrizia; Migliori, Salvina; Sasso, Elisa; Marfisi, Rosa Maria; Tognoni, Gianni; Sgaroni, Guya; Noro, Gabriele; Mattiuzzo, Mara

    2004-01-01

    In spite of the progresses of knowledge and care, pressure sores continue to be a clinically relevant problem. A double blind randomised controlled trial was organised to assess the efficacy of triticum vulgaris (Fitostimoline) vs placebo in the re-epithelisation of superficial pressure sores. Patients with stage NPUAP II or superficial pressure sores, with an expected survival of more than 3 months and eligible for a follow-up up to 8 weeks were included, over a period of 2 years in 46 clinical sites. The protocol was approved by local ethical committees and informed consent was obtained before randomisation. Medications were performed by nurses if the patient was hospitalised and by nurses or properly instructed caregivers at home. Weekly follow-up controls were assumed by nurses. Out of the 294 randomised patients 270 were included in the analyses. The two groups are comparable for the main characteristics except for Norton Scale mean values, less severe in the group assigned to active treatment (10.1+/-3.7 vs 8.9+/-3.2). The mean follow-up was of 3.8 and 4.2 weeks with a mean duration of 26+/-18 and 29+/-18 days for the experimental group and controls respectively. Seventy-six patients in the treatment group and controls (58.0 and 54.7) had their lesions re-epithelized. Adjusting results for age, initial Norton and Push scores there are no differences between treated and controls (OR 0.99 95% IC 0.60-1.67). This multicentre study, sponsored by a research group of nurses, failed to support the hypothesis that triticum vulgaris, the active component of the product Fitostimoline, given on top of recommended treatment, provides a specific therapeutic advantage in terms of frequency and timing of re-epithelization in superficial pressure sores.

  3. Using Pressure and Alteration Indicators to Assess River Morphological Quality: Case Study of the Prahova River (Romania

    Directory of Open Access Journals (Sweden)

    Gabriela Ioana-Toroimac

    2015-06-01

    Full Text Available River morphological quality assessment, derived from quantification of human pressures as well as river channel alteration, is a demand of the Water Framework Directive (WFD in terms of integrating hydromorphological elements in defining ecological status. Our study’s aim is to contribute to the hydromorphological evaluation by proposing indicators and separating classes, based on a revisited Morphological Quality Index (rMQI protocol. The rMQI is based on 12 indicators of human pressures, 10 indicators of channel form adjustments, and 11 indicators of functionality. The rMQI scoring system allows for the quantification of changes when compared to reference conditions, be they undisturbed or nearly undisturbed by human interventions, with absent channel adjustments and a functioning natural river style. We used the lower, meandering sector of the Prahova River to demonstrate our assessment methodology. The Lower Prahova River suffers from a minor local intervention and a diminishing intensity of fluvial processes specific to a meandering style. Meanders geometry was affected by significant changes that included a decrease in the radius of curvature, width and width–to–mean–depth ratio. We concluded that the Lower Prahova River has a good morphological quality, which is rated as second class on a scale of five levels, from natural to severely modified. We recommend an improvement in the hydromorphological evaluation protocol in Romania by additional indicators for morphological alterations specific to each channel pattern.

  4. Effects of intra-abdominal pressure on liver function assessed with the LiMON in critically ill patients.

    Science.gov (United States)

    Inal, Mehmet Turan; Memis, Dilek; Sezer, Y Atakan; Atalay, Meltem; Karakoc, Abdullah; Sut, Necdet

    2011-06-01

    Intra-abdominal pressure (IAP) and intra-abdominal hypertension (IAH) are associated with significant morbidity and mortality in critically ill patients. Our aim was to assess the effects of IAH on liver function using the noninvasive liver function monitoring system LiMON and to assess the prognostic value of IAP in critically ill patients. We conducted a retrospective analysis of critically ill patients who were treated in the intensive care unit (ICU). The IAP and indocyanine green plasma disappearance rate (ICG-PDR) measurements were made within 24 hours after admission to the ICU and repeated 12 hours later. Intra-abdominal pressure was measured via a Foley bladder catheter, and ICG elimination tests were conducted concurrently using the LiMON. We included 30 critically ill patients (17 women and 13 men aged 28-89 yr) in our analysis. Statistical analysis showed that the baseline IAP values were significantly higher among nonsurvivors than survivors (19.38 [standard deviation; SD 2.08] v. 13.07 [SD 0.99]). The twelfth-hour IAP values were higher than baseline measurements among nonsurvivors (21.50 [SD 1.96]) and lower than baseline measurements among survivors (11.71 [SD 1.54]); the difference between groups was significant (p LiMON is a good predictor of the effects of IAP on liver function and, thus, can be recommended for the evaluation of critically ill patients.

  5. CFD simulations of filling and emptying of hydrogen tanks

    OpenAIRE

    MELIDEO DANIELE; BARALDI DANIELE; ACOSTA IBORRA BEATRIZ; ORTIZ CEBOLLA RAFAEL; MORETTO PIETRO

    2016-01-01

    During the filling of hydrogen tanks high temperatures can be generated inside the vessel because of the gas compression while during the emptying low temperatures can be reached because of the gas expansion. The design temperature range goes from 40 C to 85 C. Temperatures outside that range could affect the mechanical properties of the tank materials. CFD analyses of the filling and emptying processes have been performed in the HyTransfer project. To assess the accuracy of the CFD model the...

  6. Assessment of renal artery stenosis using both resting pressures ratio and fractional flow reserve: relationship to angiography and ultrasonography.

    Science.gov (United States)

    Kadziela, Jacek; Witkowski, Adam; Januszewicz, Andrzej; Cedro, Krzysztof; Michałowska, Ilona; Januszewicz, Magdalena; Kabat, Marek; Prejbisz, Aleksander; Kalińczuk, Lukasz; Zieleń, Piotr; Michel-Rowicka, Katarzyna; Warchoł, Ewa; Rużyłło, Witold

    2011-08-01

    BACKGROUND. Clinical benefit from renal artery revascularization remains controversial, probably because of inaccurate stenosis severity assessment. Objective. The aim of the study was to evaluate resting translesional pressures ratio and renal fractional flow reserve (rFFR) in relation to angiography and Doppler duplex ultrasonography in patients with at least moderate renal artery stenosis (RAS). METHODS. 44 hypertensive patients (48% of males, mean age 65 years) with at least moderate RAS were investigated. Translesional systolic pressure gradient (TSPG), resting Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR - after intrarenal administration of papaverine - were evaluated. Quantitative angiographic analysis of stenosis severity was performed including minimal lumen diameter (MLD) and percent diameter stenosis (DS) assessment. Renal/aortic ratio (RAR), resistive index (RI) and deltaRI (side-to side difference) were obtained in Doppler-duplex ultrasonography. The predictive value of selected variables was calculated using receiver-operating characteristics curves. RESULTS. Mean Pd/Pa ratio was 0.86 ± 0.12 and decreased to 0.79 ± 0.13 after papaverine administration. Both Pd/Pa ratio and rFFR strongly correlated with TSPG (r = -0.92, p ratio and 0.80 for rFFR. CONCLUSIONS. Mean Pd/Pa ratio and rFFR strongly correlated with angiographic data and in less pronounced manner with ultrasound parameters reflecting intrarenal blood flow. The best accuracy cut-off points for severe RAS predicting were 0.93 and 0.80, respectively.

  7. Quantitative metrics for assessing predicted climate change pressure on North American tree species

    Science.gov (United States)

    Kevin M. Potter; William W. Hargrove

    2013-01-01

    Changing climate may pose a threat to forest tree species, forcing three potential population-level responses: toleration/adaptation, movement to suitable environmental conditions, or local extirpation. Assessments that prioritize and classify tree species for management and conservation activities in the face of climate change will need to incorporate estimates of the...

  8. Impact of epoetin alfa on left ventricular structure, function, and pressure volume relations as assessed by cardiac magnetic resonance: the heart failure preserved ejection fraction (HFPEF) anemia trial.

    Science.gov (United States)

    Green, Philip; Babu, Benson A; Teruya, Sergio; Helmke, Stephen; Prince, Martin; Maurer, Mathew S

    2013-01-01

    Anemia, a common comorbidity in older adults with heart failure and a preserved ejection fraction (HFPEF), is associated with worse outcomes. The authors quantified the effect of anemia treatment on left ventricular (LV) structure and function as measured by cardiac magnetic resonance (CMR) imaging. A prospective, randomized single-blind clinical trial (NCT NCT00286182) comparing the safety and efficacy of epoetin alfa vs placebo for 24 weeks in which a subgroup (n=22) had cardiac magnetic resonance imaging (MRI) at baseline and after 3 and 6 months to evaluate changes in cardiac structure and function. Pressure volume (PV) indices were derived from MRI measures of ventricular volume coupled with sphygmomanometer-measured pressure and Doppler estimates of filling pressure. The end-systolic and end-diastolic PV relations and the area between them as a function of end-diastolic pressure, the isovolumic PV area (PVAiso), were calculated. Patients (75±10 years, 64% women) with HFPEF (EF=63%±15%) with an average hemoglobin of 10.3±1.1 gm/dL were treated with epoetin alfa using a dose-adjusted algorithm that increased hemoglobin compared with placebo (PHFPEF resulted in a significant increase in hemoglobin, without evident change in LV structure, function, or pressure volume relationships as measured quantitatively using CMR imaging.

  9. Unsteady Capillary Filling By Electrocapillarity

    Science.gov (United States)

    Kang, In Seok; Lee, Jung A.

    2016-11-01

    Unsteady filling of electrolyte solution inside a nanochannel by the electrocapillarity effect is studied. The filling rate is predicted as a function of the bulk concentration of the electrolyte, the surface potential (or surface charge density), and the cross sectional shape of the channel. Since the driving force of the flow is the electrocapillarity, it is first analyzed by using the solution of the Poisson-Boltzmann equation. From the analysis, it is found that the results for many different cross sectional shapes can be unified with good accuracy if the hydraulic radius is adopted as the characteristic length scale of the problem. Especially in the case of constant surface potential, for both limits of κh -> 0 and κh -> ∞ , it can be shown theoretically that the electrocapillarity is independent of the cross sectional shape if the hydraulic radius is the same. In order to analyze the geometric effects more systematically, we consider the regular N-polygons with the same hydraulic radius and the rectangles of different aspect ratios. Washburn's approach is then adopted to predict the filling rate of electrolyte solution inside a nanaochannel. It is found that the average filling velocity decreases as N increases in the case of regular N-polygons with the same hydraulic radius. This is because of that the regular N-polygons of the same hydraulic radius share the same inscribing circle. This work has been supported by BK21+ program.

  10. Filling in the retinal image

    Science.gov (United States)

    Larimer, James; Piantanida, Thomas

    1990-01-01

    The optics of the eye form an image on a surface at the back of the eyeball called the retina. The retina contains the photoreceptors that sample the image and convert it into a neural signal. The spacing of the photoreceptors in the retina is not uniform and varies with retinal locus. The central retinal field, called the macula, is densely packed with photoreceptors. The packing density falls off rapidly as a function of retinal eccentricity with respect to the macular region and there are regions in which there are no photoreceptors at all. The retinal regions without photoreceptors are called blind spots or scotomas. The neural transformations which convert retinal image signals into percepts fills in the gaps and regularizes the inhomogeneities of the retinal photoreceptor sampling mosaic. The filling-in mechamism plays an important role in understanding visual performance. The filling-in mechanism is not well understood. A systematic collaborative research program at the Ames Research Center and SRI in Menlo Park, California, was designed to explore this mechanism. It was shown that the perceived fields which are in fact different from the image on the retina due to filling-in, control some aspects of performance and not others. Researchers have linked these mechanisms to putative mechanisms of color coding and color constancy.

  11. Space-filling polyhedral sorbents

    Science.gov (United States)

    Haaland, Peter

    2016-06-21

    Solid sorbents, systems, and methods for pumping, storage, and purification of gases are disclosed. They derive from the dynamics of porous and free convection for specific gas/sorbent combinations and use space filling polyhedral microliths with facial aplanarities to produce sorbent arrays with interpenetrating interstitial manifolds of voids.

  12. Filling of charged cylindrical capillaries

    NARCIS (Netherlands)

    Das, Siddhartha; Chanda, Sourayon; Eijkel, J.C.T.; Tas, N.R.; Chakraborty, Suman; Mitra, Sushanta K.

    2014-01-01

    We provide an analytical model to describe the filling dynamics of horizontal cylindrical capillaries having charged walls. The presence of surface charge leads to two distinct effects: It leads to a retarding electrical force on the liquid column and also causes a reduced viscous drag force because

  13. Relationship among diastolic intraventricular pressure gradients, relaxation, and preload : impact of age and fitness

    NARCIS (Netherlands)

    Popovic, Z.B.; Prasad, A.; Garcia, M.J.; Arbab-Zadeh, A.; Borowski, A.; Dijk, E.; Greenberg, N.L.; Levine, B.D.; Thomas, J.D.

    2006-01-01

    Diastolic intraventricular pressure gradients (IVPGs) are a measure of the ability of the ventricle to facilitate its filling using diastolic suction. We assessed 15 healthy young but sedentary subjects, aged <50 yr (young subjects; age, 35 +/- 9 yr); 13 healthy but sedentary seniors, aged >65 yr wi

  14. Methodology for Calculating a Complex Index for Assessing the Pressure of Regional Indicators on Public Administration

    Directory of Open Access Journals (Sweden)

    Gheorghe SĂVOIU

    2013-10-01

    Full Text Available This paper aims to investigate the correlations between regional employment in public administration and several major phenomena, starting from the case of Romania’s regions trying to find a territorial statistical solution for measuring the process itself. In this article, especially in its own methodology and methods, the territorial index is estimated as a result of the pressure of other major regional factors, synthesized by specific indicators and indices. The first section describes some conceptual and legal aspects of the regional employment level in public administration and contemporary statistical delimitation of regions in Romania. The second section underlines the originality of the methods and methodology, and the third section defines the three characteristics of the new solutions: the relative temporal, spatial and structural proportionality, the relative trends of an adequate econometric model, and the limits of regional concentration and diversification using the Gini-Struck coefficient in an ABC curve. The analysis of the complexity and impact of the new statistical instruments on regional employment in public administration, its characteristic Romanian limits and the final conclusion show that only an original methodology, some innovative methods and new statistical instruments lead to a better and adequate solution for an optimum level of employment.

  15. Experimental Assessment of Photon Fluence Rate Distributions in a Medium-Pressure UV Photoreactor.

    Science.gov (United States)

    Li, Mengkai; Qiang, Zhimin; Wang, Chen; Bolton, James R; Blatchley Iii, Ernest R

    2017-02-28

    The performance of a medium-pressure (MP) mercury lamp photoreactor is strongly influenced by the spatial photon fluence rate (PFR) distributions which are wavelength-dependent. To address this issue, PFR distributions in an MP lamp photoreactor were measured using a 360-degree response microfluorescent silica detector (MFSD). To accurately express the optical behavior in an MP photoreactor, PFR, MFSD response PFR (PFRMFSD), and effective germicidal PFR (PFRGER) were defined and compared. The measured axial and radial PFRMFSD values agreed well with the corresponding results from a simulation model (UVCalc). The PFR and PFRGER were obtained from the measured PFRMFSD by using correction factors calculated by the UVCalc. Under identical UV transmittance (254 nm) conditions (75% and 85%), the weighted average PFRGER values were 13.3-18.7% lower than the corresponding PFR values, indicating that PFRGER, rather than PFR should be used in MP photoreactor design to meet disinfection standards. Based on measured lamp output, medium absorption spectrum, MFSD response, and microbial DNA response spectrum, the detailed relationships between the PFR, PFRMFSD, and PFRGER were elucidated. This work proposes a new method for the accurate description of wavelength-dependent PFR distributions in MP photoreactors, thus providing an important tool for the optimal design of these systems.

  16. Kurtosis corrected sound pressure level as a noise metric for risk assessment of occupational noises.

    Science.gov (United States)

    Goley, G Steven; Song, Won Joon; Kim, Jay H

    2011-03-01

    Current noise guidelines use an energy-based noise metric to predict the risk of hearing loss, and thus ignore the effect of temporal characteristics of the noise. The practice is widely considered to underestimate the risk of a complex noise environment, where impulsive noises are embedded in a steady-state noise. A basic form for noise metrics is designed by combining the equivalent sound pressure level (SPL) and a temporal correction term defined as a function of kurtosis of the noise. Several noise metrics are developed by varying this basic form and evaluated utilizing existing chinchilla noise exposure data. It is shown that the kurtosis correction term significantly improves the correlation of the noise metric with the measured hearing losses in chinchillas. The average SPL of the frequency components of the noise that define the hearing loss with a kurtosis correction term is identified as the best noise metric among tested. One of the investigated metrics, the kurtosis-corrected A-weighted SPL, is applied to a human exposure study data as a preview of applying the metrics to human guidelines. The possibility of applying the noise metrics to human guidelines is discussed.

  17. Probabilistic reasoning under time pressure: an assessment in Italian, Spanish and English psychology undergraduates

    Science.gov (United States)

    Agus, M.; Hitchcott, P. K.; Penna, M. P.; Peró-Cebollero, M.; Guàrdia-Olmos, J.

    2016-11-01

    Many studies have investigated the features of probabilistic reasoning developed in relation to different formats of problem presentation, showing that it is affected by various individual and contextual factors. Incomplete understanding of the identity and role of these factors may explain the inconsistent evidence concerning the effect of problem presentation format. Thus, superior performance has sometimes been observed for graphically, rather than verbally, presented problems. The present study was undertaken to address this issue. Psychology undergraduates without any statistical expertise (N = 173 in Italy; N = 118 in Spain; N = 55 in England) were administered statistical problems in two formats (verbal-numerical and graphical-pictorial) under a condition of time pressure. Students also completed additional measures indexing several potentially relevant individual dimensions (statistical ability, statistical anxiety, attitudes towards statistics and confidence). Interestingly, a facilitatory effect of graphical presentation was observed in the Italian and Spanish samples but not in the English one. Significantly, the individual dimensions predicting statistical performance also differed between the samples, highlighting a different role of confidence. Hence, these findings confirm previous observations concerning problem presentation format while simultaneously highlighting the importance of individual dimensions.

  18. Use of a risk assessment method to improve the safety of negative pressure wound therapy.

    Science.gov (United States)

    Lelong, Anne-Sophie; Martelli, Nicolas; Bonan, Brigitte; Prognon, Patrice; Pineau, Judith

    2014-06-01

    To conduct a risk analysis of the negative pressure wound therapy (NPWT) care process and to improve the safety of NPWT, a working group of nurses, hospital pharmacists, physicians and hospital managers performed a risk analysis for the process of NPWT care. The failure modes, effects and criticality analysis (FMECA) method was used for this analysis. Failure modes and their consequences were defined and classified as a function of their criticality to identify priority actions for improvement. By contrast to classical FMECA, the criticality index (CI) of each consequence was calculated by multiplying occurrence, severity and detection scores. We identified 13 failure modes, leading to 20 different consequences. The CI of consequences was initially 712, falling to 357 after corrective measures were implemented. The major improvements proposed included the establishment of 6-monthly training cycles for nurses, physicians and surgeons and the introduction of computerised prescription for NPWT. The FMECA method also made it possible to prioritise actions as a function of the criticality ranking of consequences and was easily understood and used by the working group. This study is, to our knowledge, the first to use the FMECA method to improve the safety of NPWT.

  19. Nondestructive Methods and Special Test Instrumentation Supporting NASA Composite Overwrapped Pressure Vessel Assessments

    Science.gov (United States)

    Saulsberry, Regor; Greene, Nathanael; Cameron, Ken; Madaras, Eric; Grimes-Ledesma, Lorie; Thesken, John; Phoenix, Leigh; Murthy, Pappu; Revilock, Duane

    2007-01-01

    Many aging composite overwrapped pressure vessels (COPVs), being used by the National Aeronautics and Space Administration (NASA) are currently under evaluation to better quantify their reliability and clarify their likelihood of failure due to stress rupture and age-dependent issues. As a result, some test and analysis programs have been successfully accomplished and other related programs are still in progress at the NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) and other NASA centers, with assistance from the commercial sector. To support this effort, a group of Nondestructive Evaluation (NDE) experts was assembled to provide NDE competence for pretest evaluation of test articles and for application of NDE technology to real-time testing. Techniques were required to provide assurance that the test article had adequate structural integrity and manufacturing consistency to be considered acceptable for testing and these techniques were successfully applied. Destructive testing is also being accomplished to better understand the physical and chemical property changes associated with progression toward "stress rupture" (SR) failure, and it is being associated with NDE response, so it can potentially be used to help with life prediction. Destructive work also includes the evaluation of residual stresses during dissection of the overwrap, laboratory evaluation of specimens extracted from the overwrap to evaluate physical property changes, and quantitative microscopy to inform the theoretical micromechanics.

  20. Assessing the Causality between Blood Pressure and Retinal Vascular Caliber through Mendelian Randomisation

    Science.gov (United States)

    Li, Ling-Jun; Liao, Jiemin; Cheung, Carol Yim-Lui; Ikram, M. Kamran; Shyong, Tai E.; Wong, Tien-Yin; Cheng, Ching-Yu

    2016-02-01

    We aimed to determine the association between blood pressure (BP) and retinal vascular caliber changes that were free from confounders and reverse causation by using Mendelian randomisation. A total of 6528 participants from a multi-ethnic cohort (Chinese, Malays, and Indians) in Singapore were included in this study. Retinal arteriolar and venular caliber was measured by a semi-automated computer program. Genotyping was done using Illumina 610-quad chips. Meta-analysis of association between BP, and retinal arteriolar and venular caliber across three ethnic groups was performed both in conventional linear regression and Mendelian randomisation framework with a genetic risk score of BP as an instrumental variable. In multiple linear regression models, each 10 mm Hg increase in systolic BP, diastolic BP, and mean arterial BP (MAP) was associated with significant decreases in retinal arteriolar caliber of a 1.4, 3.0, and 2.6 μm, and significant decreases in retinal venular caliber of a 0.6, 0.7, and 0.9 μm, respectively. In a Mendelian randomisation model, only associations between DBP and MAP and retinal arteriolar narrowing remained yet its significance was greatly reduced. Our data showed weak evidence of a causal relationship between elevated BP and retinal arteriolar narrowing.

  1. Tribology of Graphite-Filled Polystyrene

    Directory of Open Access Journals (Sweden)

    Raffaele Gilardi

    2016-06-01

    Full Text Available Self-lubricating polymer compounds are currently used for a wide range of applications such as bearings, gears, and water meters. Under severe conditions such as high pressure, high velocity, and/or high temperatures, the material fails (PV limit. In this study, we investigated the effect of graphite on the tribological properties of polystyrene (PS with “ball-on-three-plates” tests. Graphite-filled PS plates were produced via an internal mixer and compression molding. Unhardened steel (1.4401 and nylon (PA66 balls were used for the tribological tests. Our results indicate that graphite loading, graphite type, and particle size have a big influence on the friction coefficient, the wear resistance, and the PV limit of PS both against steel and PA66. In particular, primary synthetic graphite performs better than secondary synthetic graphite due to the higher degree of crystallinity.

  2. Neutron transmission measurements on hydrogen filled microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Dyrnjaja, Eva, E-mail: dyrnjaja@ati.ac.at [Vienna University of Technology, Institute of Atomic and Subatomic Physics, Stadionallee 2, Vienna (Austria); Hummel, Stefan, E-mail: hummel@fotec.at [FOTEC GmbH, Viktor Kaplan-Straße 2, 2700 Wiener Neustadt (Austria); Keding, Marcus, E-mail: keding@fotec.at [FOTEC GmbH, Viktor Kaplan-Straße 2, 2700 Wiener Neustadt (Austria); Smolle, Marie-Theres, E-mail: marie-theres.smolle@tuwien.ac.at [Vienna University of Technology, Institute of Atomic and Subatomic Physics, Stadionallee 2, Vienna (Austria); Gerger, Joachim, E-mail: gerger@fotec.at [FOTEC GmbH, Viktor Kaplan-Straße 2, 2700 Wiener Neustadt (Austria); Zawisky, Michael, E-mail: zawisky@ati.ac.at [Vienna University of Technology, Institute of Atomic and Subatomic Physics, Stadionallee 2, Vienna (Austria)

    2014-01-01

    Hollow microspheres are promising candidates for future hydrogen storage technologies. Although the physical process for hydrogen diffusion through glass is well understood, measurements of static quantities (e.q. hydrogen pressure inside the spheres) as well as dynamic properties (e.g. diffusion rate of hydrogen through glass) are still difficult to handle due to the small size of the spheres (d≈15μm). For diffusion rate measurements, the long-term stability of the experiment is also mandatory due to the relatively slow diffusion rate. In this work, we present an accurate and long-term stable measurement technique for static and dynamic properties, using neutron radiography. Furthermore, possible applications for hydrogen filled microspheres within the scope of radiation issues are discussed.

  3. Global assessments of submarine groundwater discharge and groundwater resources under the pressures of humanity and climate change

    Science.gov (United States)

    Taniguchi, M.; Burnett, W. C.; Aureli, A.

    2006-12-01

    We report here the global-scale assessment of both fresh and saline groundwater discharges based solely on observational data. Prior estimates have been limited to various water balance and hydrodynamic modeling calculations and range over orders of magnitude. Our observations suggest the global volumes of fresh groundwater discharge and recirculated seawater per unit shoreline length depending on the distance from the shoreline, precipitation, and seawater depth. On a world-wide scale, these flows are compared with the global river discharge. We show via automated measurements that precipitation and wave pumping are important controls of terrestrial (fresh) and marine-induced (recirculated seawater) subterranean flows, respectively. The Groundwater Resources Assessment under the Pressures of Humanity and Climate Changes (GRAPHIC) Project, an initiative of UNESCO International Hydrological Programme (IHP), seeks to improve the understanding and management of groundwater as a vital contributor to the global water cycle, ecosystems and communities, under changing climatic and anthropomorphic regimes. GRAPHIC focuses on variations of the flows, stocks, and quality of groundwater recharge, discharge and storage and on groundwater-related management and policy (http://www.chikyu.ac.jp/USE/GRAPHIC/GRAPHIC.htm). This GRAPHIC project will deal with groundwater resources assessment and future forecasting under the various pressures of humanity and climate changes. The structure of the GRAPHIC project has been divided into; (A) Subjects; thematic, cross-region issues, (B) Methods; methodological approaches (1:Database and Monitoring, 2:Satelite GRACE (Gravity Recovery and Climate Experiment), 3:Modeling and Simulation, 4:Paleohydrology), and (C) Regions; representative geographical areas, where pilot studies will be made.

  4. Assessment of Corneal Biomechanical Properties and Intraocular Pressure in Myopic Spanish Healthy Population

    Directory of Open Access Journals (Sweden)

    María A. del Buey

    2014-01-01

    Full Text Available Purpose. To examine biomechanical parameters of the cornea in myopic eyes and their relationship with the degree of myopia in a western healthy population. Methods. Corneal hysteresis (CH, corneal resistance factor (CRF, Goldmann correlated intraocular pressure (IOP, and corneal compensated IOP (IOPcc were measured using the ocular response analyzer (ORA in 312 eyes of 177 Spanish subjects aged between 20 and 56 years. Refraction was expressed as spherical equivalent (SE, which ranged from 0 to −16.50 diopters (D (mean: −3.88±2.90 D. Subjects were divided into four groups according to their refractive status: group 1 or control group: emmetropia (-0.50≤SE0.05; nevertheless, IOPcc was significantly higher in the moderately myopic (15.47±2.47 mmHg and highly myopic (16.14±2.59 mmHg groups than in the emmetropia (15.15±2.06 mmHg and low myopia groups (14.53±2.37 mmHg. No correlation between age and the measured parameters was found. CH and IOPcc were weakly but significantly correlated with SE (r=0.171, P=0.002 and r=-0.131, P=0.021, resp.. Conclusions. Present study showed only a very weak, but significant, correlation between CH and refractive error, with CH being lower in both moderately and highly myopic eyes than that in the emmetropic and low myopic eyes. These changes in biomechanical properties of the cornea may have an impact on IOP measurement, increasing the risk of glaucoma.

  5. NPH Log: Validation of a New Assessment Tool Leading to Earlier Diagnosis of Normal Pressure Hydrocephalus.

    Science.gov (United States)

    Jusué-Torres, Ignacio; Lu, Jennifer; Robison, Jamie; Hoffberger, Jamie B; Hulbert, Alicia; Sanyal, Abanti; Wemmer, Jan; Elder, Benjamin D; Rigamonti, Daniele

    2016-06-27

    Early treatment of normal pressure hydrocephalus (NPH) yields better postoperative outcomes. Our current tests often fail to detect significant changes at early stages. We developed a new scoring system (LP log score) to determine if this tool is more sensitive in detecting clinical differences than current tests. Sixty-two consecutive new patients with suspected idiopathic NPH were studied. Secondary, previously treated and obstructive cases were not included. We collected age, pre- and post-lumbar puncture (LP) Tinetti, Timed Up and Go (TUG) Test, European NPH scale, and LP log scores. The LP log score is recorded at baseline and for seven consecutive days after removing 40 cc of cerebrospinal fluid (CSF) via LP. We studied the diagnostic accuracy of the tests for surgical indication. The post-LP log showed improvement in 90% of people with good baseline gait tests and in 93% of people who did not show any pre-LP and post-LP change in gait tests. Sensitivity, specificity, and accuracy to detect intention to treat when positive post-LP improvements were 4%, 100%, and 24%, respectively, for TUG, 21%, 86%, and 34%, respectively, for the Tinetti Mobility Test, 66%, 29%, and 58%, respectively, for Medical College of Virginia (MCV) grade, and 98%, 33%, and 85%, respectively, for LP log score. Pre-LP and post-LP TUG improvement and pre-LP and post-LP Tinetti improvement were not associated with a surgical indication (p > 0.05). LP log improvement was associated with surgical indication odds ratio (OR): 24.5 95% CI (2.4-248.12) (p = 0.007). LP log showed better sensitivity, diagnostic accuracy, and association with surgical indication than the current diagnostic approach. An LP log may be useful detecting NPH patients at earlier stages and, therefore, yield better surgical outcomes.

  6. NPH Log: Validation of a New Assessment Tool Leading to Earlier Diagnosis of Normal Pressure Hydrocephalus

    Science.gov (United States)

    Lu, Jennifer; Robison, Jamie; Hoffberger, Jamie B; Hulbert, Alicia; Sanyal, Abanti; Wemmer, Jan; Elder, Benjamin D; Rigamonti, Daniele

    2016-01-01

    Introduction: Early treatment of normal pressure hydrocephalus (NPH) yields better postoperative outcomes. Our current tests often fail to detect significant changes at early stages. We developed a new scoring system (LP log score) to determine if this tool is more sensitive in detecting clinical differences than current tests. Material and Methods: Sixty-two consecutive new patients with suspected idiopathic NPH were studied. Secondary, previously treated and obstructive cases were not included. We collected age, pre- and post-lumbar puncture (LP) Tinetti, Timed Up and Go (TUG) Test, European NPH scale, and LP log scores. The LP log score is recorded at baseline and for seven consecutive days after removing 40 cc of cerebrospinal fluid (CSF) via LP. We studied the diagnostic accuracy of the tests for surgical indication. Results: The post-LP log showed improvement in 90% of people with good baseline gait tests and in 93% of people who did not show any pre-LP and post-LP change in gait tests. Sensitivity, specificity, and accuracy to detect intention to treat when positive post-LP improvements were 4%, 100%, and 24%, respectively, for TUG, 21%, 86%, and 34%, respectively, for the Tinetti Mobility Test, 66%, 29%, and 58%, respectively, for Medical College of Virginia (MCV) grade, and 98%, 33%, and 85%, respectively, for LP log score. Pre-LP and post-LP TUG improvement and pre-LP and post-LP Tinetti improvement were not associated with a surgical indication (p > 0.05). LP log improvement was associated with surgical indication odds ratio (OR): 24.5 95% CI (2.4-248.12) (p = 0.007). Conclusions: LP log showed better sensitivity, diagnostic accuracy, and association with surgical indication than the current diagnostic approach. An LP log may be useful detecting NPH patients at earlier stages and, therefore, yield better surgical outcomes. PMID:27489752

  7. 49 CFR 178.59 - Specification 8 steel cylinders with porous fillings for acetylene.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 8 steel cylinders with porous fillings for acetylene. 178.59 Section 178.59 Transportation Other Regulations Relating to Transportation... cylinders with porous fillings for acetylene. (a) Type and service pressure. A DOT 8 cylinder is a...

  8. 49 CFR 178.60 - Specification 8AL steel cylinders with porous fillings for acetylene.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 8AL steel cylinders with porous fillings for acetylene. 178.60 Section 178.60 Transportation Other Regulations Relating to Transportation... cylinders with porous fillings for acetylene. (a) Type and service pressure. A DOT 8AL cylinder is...

  9. Impact of antihypertensive combination and monotreatments on blood pressure variability: assessment by old and new indices. Data from a large ambulatory blood pressure monitoring database.

    LENUS (Irish Health Repository)

    Parati, Gianfranco

    2014-06-01

    High 24-h ambulatory blood pressure (ABP) variability is associated with poor cardiovascular outcomes. We analysed a large ABP monitoring database containing data from hypertensive patients treated with telmisartan\\/amlodipine combination or various monotherapies with the aim of quantifying the 24-h distribution of blood pressure (BP) reduction by treatment through the smoothness index and of developing and testing a new treatment-on-variability index (TOVI) to quantify the effects of treatment on both mean BP and BP variability.

  10. Purposes, paradigms and pressure groups: Accountability and sustainability in EU environmental assessment, 1985-2010

    Energy Technology Data Exchange (ETDEWEB)

    Sheate, William R., E-mail: w.sheate@imperial.ac.uk

    2012-02-15

    Twenty five years since the introduction of the European Union (EU) environmental impact assessment (EIA) Directive in 1985 this paper reflects on the extent to which environmental assessment (EA) processes, over the course of their evolution over the last 25 years in the EU, have provided a platform for enhancing accountability and sustainability. Surprisingly-in the context of legal mandates for EA-there is little reference in the EA literature explicitly to the literature on accountability and the role EA may play in this increasingly important aspect of governance. The paper explores EA implementation principally from an environmentalist perspective and particularly the way in which NGOs and other advocates for the environment in the UK and EU have used the EA legislation as a lever for increasing democratic, corporate and professional accountability of proponents and decision-makers alike. From an a historical analysis, including two historical EIA case studies and two contemporary SEA case studies, it becomes clear that EA has had an important role to play-at the legislative level in providing the requirements for accountability, and at the implementation level as the lever that can be used to hold individuals, organisations and authorities to account for their actions. The relationship with the shift to sustainability is a close one, since sustainable development demands greater public involvement in decision-making and greater accountability of executive decisions to the public. The lessons from this analysis allow the development of a nascent policy-oriented theory regarding EA's role in accountability, which provides a framework for a distinctive new area of EA research and policy analysis. Moreover, an accountability perspective on EA could help re-frame EA for policy makers from being purely an informational and procedural instrument to one which promotes better accountability and sustainability simultaneously. - Highlights: Black

  11. Precision and accuracy of a new device (CNAPTM) for continuous non-invasive arterial pressure monitoring: assessment during general anaesthesia.

    Science.gov (United States)

    Jeleazcov, C; Krajinovic, L; Münster, T; Birkholz, T; Fried, R; Schüttler, J; Fechner, J

    2010-09-01

    Continuous non-invasive arterial pressure measured with CNAP (CNAP) has been shown to be superior to intermittent oscillometric measurements during procedural sedation and spinal anaesthesia. We assessed the performance of CNAP during general anaesthesia by analysis of agreement with invasive measurements of arterial pressure (AP). Eighty-eight patients undergoing elective abdominal surgery, cardio-, or neurosurgery were included in the study. Systolic, diastolic, and mean AP measured by an intra-arterial catheter in the radial artery (IAP) were compared with those obtained by CNAP from the same arm. Data were analysed to determine the precision (i.e. measurement error) and accuracy (i.e. systematic error) of beat-to-beat CNAP values with respect to IAP. Also, we compared the frequency of fast changes in AP (FCAP) and hypotension (IOH) by both methods. CNAP precision of 4.5, 3.1, and 3.2 mm Hg (systolic, diastolic, and mean AP, respectively) was not significantly different from IAP precision, and CNAP accuracy was +6.7, -5.6, and -1.6 mm Hg. The frequency of AP pairs having a difference within the calculated limits of agreement was 81%, 64%, and 76% for systolic, diastolic, and mean AP, respectively. The calculated limits of agreement were +/-17.6, +/-11.4, and +/-12.0 mm, Hg, respectively. CNAP and IAP detected simultaneously to 82.1% FCAP and to 84.6% IOH. CNAP provides real-time estimates of arterial pressure comparable with those generated by an invasive intra-arterial catheter system during general anaesthesia.

  12. Translation, modification and validation of the Chinese version of a knowledge assessment instrument regarding pressure ulcer prevention

    Institute of Scientific and Technical Information of China (English)

    Ming Liu; Hao-Bin Yuan; Wei-Ju Chen; Chiuyin Poon; Meihua Hsu; Bo Zhang

    2016-01-01

    Objective: This study sought to translate, modify and validate an instrument developed by Beckman and colleagues to assess the knowledge of clinical nurses regarding pressure ulcers. Methods: A methodological study design was used. The instrument was translated into Chinese and back-translated into English. A six-expert panel was invited to evaluate the content validity, and a pilot test was subsequently performed on the test-retest stability of the translated instrument. A convenience sampling method was used to recruit 240 nurses from a university teaching hospital in the Mainland of China. In total, 186 valid questionnaires were collected with a 77.5%valid return rate. The validity of the multiple-choice test items (item difficulties and discriminating indices) and internal consistency reli-ability were evaluated. Results: The translated and modified instrument demonstrated acceptable psychometric properties, as follows: (1) the overall content validity index (CVI) was 0.91, (2) the overall test-retest reliability was 0.826, (3) the item difficulty indices were between 0.46 and 0.93, (4) the overall values for discrimination were 0.28e0.55, and (5) the Cronbach's a for the internal consistency were 0.792 for the overall in-strument and 0.426e0.804 for the sub-themes. Conclusions: This study represents the first trial to translate and modify an existing instrument that measures the knowledge of pressure ulcers in a Chinese Mainland sample. The instrument demonstrated acceptable psychometric properties and could be applied in cross-cultural nursing practices, including nursing education, research and practice, to evaluate knowledge about pressure ulcer prevention.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-01-01

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

  14. Ecosystem Health Assessment at County-Scale Using the Pressure-State-Response Framework on the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Delin Liu

    2016-12-01

    Full Text Available Assessing ecosystem health is helpful to determine reasonable eco-environmental restoration and resource management strategies. Based on a pressure-state-response (PSR framework, a set of comprehensive indicators including natural, social and economic aspects was proposed and applied for assessing the ecosystem health of Yuanzhou County, Loess Plateau, Ningxia Province, China. The basic data used to calculate the values of the assessment indicators include Landsat TM image and socio-economic data, and remote sensing (RS and the geographic information system (GIS were used to process image data. The results showed that the ecosystem health conditions of most townships in Yuanzhou County were at the moderately healthy level, three townships were at the healthy level, and only two townships were at the unhelathy level; the areas (percentage at the unhealthy, moderately healthy and healthy levels were 443.91 km2 (12.66%, 2438.75 km2 (69.54% and 624.50 km2 (17.81%, respectively. The results could provide useful information for local residents and the government to take measures to improve the health conditions of their township ecosystem.

  15. User-independent assessment of conditioning pain modulation by cuff pressure algometry

    DEFF Research Database (Denmark)

    Graven-Nielsen, Thomas; Izumi, Masashi; Petersen, Kristian Kjær;

    2017-01-01

    BACKGROUND: The use of conditioning pain modulation (CPM) is hampered by poor reproducibility and lack of user-independent paradigms. This study refined the CPM paradigm by applying user-independent cuff algometry. METHODS: In 20 subjects, the CPM effect of conditioning with cuff stimulation...... (pain intensity standardized) and contralateral test stimuli were additionally evaluated (leg-arm, leg-leg, arm-thigh). The test-retest reliability in two sessions 1 month apart was assessed in five CPM protocols. RESULTS: In all protocols, the PDT, PVAS6 and PTT increased during conditioning compared...... with baseline (p CPM effect (i.e. conditioning minus baseline) for PVAS6, PTT and PPT increased for increasing conditioning intensities (p CPM effects were not significantly different for changes in conditioning durations or conditioning/test stimulus locations. In two sessions...

  16. Assessing anthropogenic pressures on groundwater using stable OH isotopes: perspectives and issues

    Science.gov (United States)

    Negrel, Philippe; Ollivier, Patrick; Flehoc, Christine; Hube, Daniel

    2015-04-01

    Large developments of isotope hydrogeology were done and well-established techniques mainly applying stable isotopes of the water molecule (hydrogen and oxygen) are now used largely to trace water provenance but also recharge processes. New methods allow the use of non-traditional isotopes (metals, compound specific stable isotope analysis CSIA...) to trace anthropogenic pressures in surface- and groundwater. Groundwater contamination in large industrial sites may come from several origins such as leakage from tanks during the production process of chemical products, liquid storage tanks, solid end product or past accumulated product in soil which is released over the time. The understanding of the origin and the further evolution of the chemical contamination in groundwater in an industrial site issued from past or current industrial activities is essential for the industrial companies regarding their environmental policies. The objective of this study was to use with an innovative way the stable isotopes of the water molecule as a low cost tool to trace pollutant plumes in groundwater and help to a better management of contaminated industrial sites. We present data on stable isotopes O and H in an European region where electrochemistry plants occur. For confidentiality purposes, the sites remain anonymous. Present day industrial activities have a direct impact on the groundwater over the site and migration of the contaminant(s) plume out of the site is supposed. We first characterize the natural groundwater background through the O-H characterization of surface water, lakes, thermal waters and regional shallow aquifers. High and low altitude recharge can be demonstrated in the area. Secondly, we used the stable isotope of the water molecule to trace over the site the impact of the Cl-rich liquor manufacturing process. Large deuterium enrichment was evidenced in the groundwater and the high values can be related to a direct contamination of the groundwater through

  17. Use of large-scale acoustic monitoring to assess anthropogenic pressures on Orthoptera communities.

    Science.gov (United States)

    Penone, Caterina; Le Viol, Isabelle; Pellissier, Vincent; Julien, Jean-François; Bas, Yves; Kerbiriou, Christian

    2013-10-01

    Biodiversity monitoring at large spatial and temporal scales is greatly needed in the context of global changes. Although insects are a species-rich group and are important for ecosystem functioning, they have been largely neglected in conservation studies and policies, mainly due to technical and methodological constraints. Sound detection, a nondestructive method, is easily applied within a citizen-science framework and could be an interesting solution for insect monitoring. However, it has not yet been tested at a large scale. We assessed the value of a citizen-science program in which Orthoptera species (Tettigoniidae) were monitored acoustically along roads. We used Bayesian model-averaging analyses to test whether we could detect widely known patterns of anthropogenic effects on insects, such as the negative effects of urbanization or intensive agriculture on Orthoptera populations and communities. We also examined site-abundance correlations between years and estimated the biases in species detection to evaluate and improve the protocol. Urbanization and intensive agricultural landscapes negatively affected Orthoptera species richness, diversity, and abundance. This finding is consistent with results of previous studies of Orthoptera, vertebrates, carabids, and butterflies. The average mass of communities decreased as urbanization increased. The dispersal ability of communities increased as the percentage of agricultural land and, to a lesser extent, urban area increased. Despite changes in abundances over time, we found significant correlations between yearly abundances. We identified biases linked to the protocol (e.g., car speed or temperature) that can be accounted for ease in analyses. We argue that acoustic monitoring of Orthoptera along roads offers several advantages for assessing Orthoptera biodiversity at large spatial and temporal extents, particularly in a citizen science framework. © 2013 Society for Conservation Biology.

  18. A pilot study of quantitative assessment of mandible advancement using pressure-flow relationship during midazolam sedation.

    Science.gov (United States)

    Ayuse, T; Hoshino, Y; Inazawa, T; Oi, K; Schneider, H; Schwartz, A R

    2006-11-01

    It has been proposed that a titration of the mandibular positioner would be a promising method for predicting the outcome of nasal continuous positive airway pressure (CPAP) therapy. This study was carried out to test the hypothesis that mandible advancement could be evaluated by analysis of inspiratory flow limitation using a titration procedure. To explore its effect, we examined upper airway pressure-flow relationships using a titrated mandible positioner during midazolam sedation. Non-flow limited inspiration occurred when the mandible was advanced 7.1 +/- 1.2 mm from centric occlusion position. In the centric occlusion position (0 mm advancement), Pcrit was -1.9 +/- 2.9 cmH2O and Rua was 23.3 +/- 4.5 cmH2O L(-1) s(-1). In the eMAP position, Pcrit was -7.3 +/- 1.9 cmH2O and Rua was 27.8 +/- 3.3 cmH2O L(-1) s(-1). Essentially no CPAP was required to overcome flow limitation in eMAP position, whereas 3.7 +/- 2.2 cmH2O CPAP was required in centric occlusion position. We conclude that assessing inspiratory flow limitation using a titrated mandible positioner was effective for estimating individual-matched mandible positions.

  19. Economic assessment of pressure sore prevention using a computerized mattress system in patients with spinal cord injury.

    Science.gov (United States)

    Catz, Amiram; Zifroni, Avi; Philo, Ora

    2005-11-15

    To assess the economic profitability of a new computerized mattress system in patients with spinal cord injuries (SCI) by comparison with two other alternatives, as an example of the use of a quantitative approach for decision-making in choosing between alternatives for sore prevention. The cost of achieving one day without signs of impending pressure sore was compared between the alternative options using cost minimization analysis. Savings in nursing costs for the three options were calculated for cost-benefit analysis. A foam mattress system is significantly cheaper than the other examined alternatives, and if the nursing manpower cost is constant and the nursing staff is capable of performing sufficient repositioning, this system would achieve the desired medical outcome at a minimal cost. However, if the nursing staff cannot perform sufficient repositioning, or if the use of nursing manpower can be adjusted to the actual need, then it is the computerized mattress system that achieves the desired outcome at the minimal cost. In this case, less than 20 New Israeli Shekels (NIS) per day spent on the equipment save NIS 45 per day in labor costs. The economic evaluation indicates that the computerized mattress system is advisable for patients with SCI who require assistance for repositioning, but its profitability depends on the employment terms of the nursing manpower. In addition, other possible alternative pressure management systems should be examined, and additional research may be needed to determine the optimal combination of such systems for a spinal cord rehabilitation department.

  20. Assessing Optimal Blood Pressure in Patients With Asymptomatic Aortic Valve Stenosis The Simvastatin Ezetimibe in Aortic Stenosis Study (SEAS)

    DEFF Research Database (Denmark)

    Nielsen, O. W.; Sajadieh, A.; Sabbah, M.

    2016-01-01

    BACKGROUND: Evidence for treating hypertension in patients with asymptomatic aortic valve stenosis is scarce. We used data from the SEAS trial (Simvastatin Ezetimibe in Aortic Stenosis) to assess what blood pressure (BP) would be optimal. METHODS: A total of 1767 patients with asymptomatic aortic...... stenosis and no manifest atherosclerotic disease were analyzed. Outcomes were all-cause mortality, cardiovascular death, heart failure, stroke, myocardial infarction, and aortic valve replacement. BP was analyzed in Cox models as the cumulative average of serially measured BP and a time-varying covariate...... to 69 mm Hg taken as reference. Low systolic and diastolic BPs increased risk in patients with moderate aortic stenosis. With a time-varying systolic BP from 130 to 139 mm Hg used as reference, mortality was increased for systolic BP ≥160 mm Hg (HR, 1.7; P=0.033) and BP of 120 to 129 mm Hg (HR, 1.6; P=0...