Extract-filter-shoot liquid chromatography with mass spectrometry for the analysis of vitamin D2 in a powdered supplement capsule and standard reference material 3280.

PubMed

Byrdwell, William Craig

2014-08-01

An "extract-filter-shoot" method for the analysis of vitamin D2, ergocalciferol, in a dry powdered dietary supplement capsule containing rice flour excipient and in a National Institute of Standards and Technology standard reference material 3280 is reported. Quantification of vitamin D2 was done by atmospheric pressure chemical ionization mass spectrometry using selected ion monitoring, two transitions of selected reaction monitoring, and extracted ion chromatograms from full scans. UV detection was used for the quantification of Vitamin D2 in the dry powder capsule, whereas interfering species rendered UV detection unreliable for standard reference material 3280. Average values for standard reference material 3280 ranged from 8.27 ± 0.58 to 8.33 ± 0.57 μg/g using internal standard calibration and response factor approaches, compared to the previous National Institute of Standards and Technology internal value for vitamin D2 of 8.78 ± 0.11 μg/g, and the recently updated reference value of 8.6 ± 2.6 μg/g. The powdered supplement capsule was found to contain 28.19 ± 0.35 to 28.67 ± 0.90 μg/capsule for a capsule labeled to contain 25.00 μg. The triacylglycerol composition of the rice flour excipient in the powdered supplement capsule determined by atmospheric pressure chemical ionization mass spectrometry is also reported. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

46 CFR 56.01-2 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Steel Pipe for High-Temperature Service (“ASTM A 106”), 56.60-1; (5) ASTM A 126-95, Standard... (1996), Standard Specification for Seamless Carbon Steel Boiler Tubes for High-Pressure Service (“ASTM A...-Resistance-Welded Carbon Steel Boiler and Superheater Tubes for High-Pressure Service (“ASTM A 226”), 56.60-1...

Calibration of Heat Stress Monitor and its Measurement Uncertainty

NASA Astrophysics Data System (ADS)

Ekici, Can

2017-07-01

Wet-bulb globe temperature (WBGT) equation is a heat stress index that gives information for the workers in the industrial areas. WBGT equation is described in ISO Standard 7243 (ISO 7243 in Hot environments—estimation of the heat stress on working man, based on the WBGT index, ISO, Geneva, 1982). WBGT is the result of the combined quantitative effects of the natural wet-bulb temperature, dry-bulb temperature, and air temperature. WBGT is a calculated parameter. WBGT uses input estimates, and heat stress monitor measures these quantities. In this study, the calibration method of a heat stress monitor is described, and the model function for measurement uncertainty is given. Sensitivity coefficients were derived according to GUM. Two-pressure humidity generators were used to generate a controlled environment. Heat stress monitor was calibrated inside of the generator. Two-pressure humidity generator, which is located in Turkish Standard Institution, was used as the reference device. This device is traceable to national standards. Two-pressure humidity generator includes reference temperature Pt-100 sensors. The reference sensor was sheltered with a wet wick for the calibration of natural wet-bulb thermometer. The reference sensor was centred into a black globe that has got 150 mm diameter for the calibration of the black globe thermometer.

46 CFR 56.01-2 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

...”), 56.10-5; 56.60-1; (4) ASTM A 106-95, Standard Specification for Seamless Carbon Steel Pipe for High...), Standard Specification for Seamless Carbon Steel Boiler Tubes for High-Pressure Service (“ASTM A 192”), 56... Steel Boiler and Superheater Tubes for High-Pressure Service (“ASTM A 226”), 56.60-1; (19) ASTM A 234/A...

46 CFR 56.01-2 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

...”), 56.10-5; 56.60-1; (4) ASTM A 106-95, Standard Specification for Seamless Carbon Steel Pipe for High...), Standard Specification for Seamless Carbon Steel Boiler Tubes for High-Pressure Service (“ASTM A 192”), 56... Steel Boiler and Superheater Tubes for High-Pressure Service (“ASTM A 226”), 56.60-1; (19) ASTM A 234/A...

Pulse Wave Velocity as Marker of Preclinical Arterial Disease: Reference Levels in a Uruguayan Population Considering Wave Detection Algorithms, Path Lengths, Aging, and Blood Pressure

PubMed Central

Farro, Ignacio; Bia, Daniel; Zócalo, Yanina; Torrado, Juan; Farro, Federico; Florio, Lucía; Olascoaga, Alicia; Alallón, Walter; Lluberas, Ricardo; Armentano, Ricardo L.

2012-01-01

Carotid-femoral pulse wave velocity (PWV) has emerged as the gold standard for non-invasive evaluation of aortic stiffness; absence of standardized methodologies of study and lack of normal and reference values have limited a wider clinical implementation. This work was carried out in a Uruguayan (South American) population in order to characterize normal, reference, and threshold levels of PWV considering normal age-related changes in PWV and the prevailing blood pressure level during the study. A conservative approach was used, and we excluded symptomatic subjects; subjects with history of cardiovascular (CV) disease, diabetes mellitus or renal failure; subjects with traditional CV risk factors (other than age and gender); asymptomatic subjects with atherosclerotic plaques in carotid arteries; patients taking anti-hypertensives or lipid-lowering medications. The included subjects (n = 429) were categorized according to the age decade and the blood pressure levels (at study time). All subjects represented the “reference population”; the group of subjects with optimal/normal blood pressures levels at study time represented the “normal population.” Results. Normal and reference PWV levels were obtained. Differences in PWV levels and aging-associated changes were obtained. The obtained data could be used to define vascular aging and abnormal or disease-related arterial changes. PMID:22666551

Comparison of three commercially available fit-test methods.

PubMed

Janssen, Larry L; Luinenburg, D Michael; Mullins, Haskell E; Nelson, Thomas J

2002-01-01

American National Standards Institute (ANSI) standard Z88.10, Respirator Fit Testing Methods, includes criteria to evaluate new fit-tests. The standard allows generated aerosol, particle counting, or controlled negative pressure quantitative fit-tests to be used as the reference method to determine acceptability of a new test. This study examined (1) comparability of three Occupational Safety and Health Administration-accepted fit-test methods, all of which were validated using generated aerosol as the reference method; and (2) the effect of the reference method on the apparent performance of a fit-test method under evaluation. Sequential fit-tests were performed using the controlled negative pressure and particle counting quantitative fit-tests and the bitter aerosol qualitative fit-test. Of 75 fit-tests conducted with each method, the controlled negative pressure method identified 24 failures; bitter aerosol identified 22 failures; and the particle counting method identified 15 failures. The sensitivity of each method, that is, agreement with the reference method in identifying unacceptable fits, was calculated using each of the other two methods as the reference. None of the test methods met the ANSI sensitivity criterion of 0.95 or greater when compared with either of the other two methods. These results demonstrate that (1) the apparent performance of any fit-test depends on the reference method used, and (2) the fit-tests evaluated use different criteria to identify inadequately fitting respirators. Although "acceptable fit" cannot be defined in absolute terms at this time, the ability of existing fit-test methods to reject poor fits can be inferred from workplace protection factor studies.

49 CFR 195.432 - Inspection of in-service breakout tanks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... low-pressure steel aboveground breakout tanks according to API Standard 653 (incorporated by reference... breakout tanks built to API Standard 2510 according to section 6 of API 510. (d) The intervals of...

49 CFR 195.432 - Inspection of in-service breakout tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... low-pressure steel aboveground breakout tanks according to API Standard 653 (incorporated by reference... breakout tanks built to API Standard 2510 according to section 6 of API 510. (d) The intervals of...

49 CFR 195.432 - Inspection of in-service breakout tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... low-pressure steel aboveground breakout tanks according to API Standard 653 (incorporated by reference... breakout tanks built to API Standard 2510 according to section 6 of API 510. (d) The intervals of...

49 CFR 195.432 - Inspection of in-service breakout tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... low-pressure steel aboveground breakout tanks according to API Standard 653 (incorporated by reference... breakout tanks built to API Standard 2510 according to section 6 of API 510. (d) The intervals of...

49 CFR 195.432 - Inspection of in-service breakout tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... low-pressure steel aboveground breakout tanks according to API Standard 653 (incorporated by reference... breakout tanks built to API Standard 2510 according to section 6 of API 510. (d) The intervals of...

Development of a primary standard for dynamic pressure based on drop weight method covering a range of 10 MPa-400 MPa

NASA Astrophysics Data System (ADS)

Salminen, J.; Högström, R.; Saxholm, S.; Lakka, A.; Riski, K.; Heinonen, M.

2018-04-01

In this paper we present the development of a primary standard for dynamic pressures that is based on the drop weight method. At the moment dynamic pressure transducers are typically calibrated using reference transducers, which are calibrated against static pressure standards. Because dynamic and static characteristics of pressure transducers may significantly differ from each other, it is important that these transducers are calibrated against dynamic pressure standards. In a method developed in VTT Technical Research Centre of Finland Ltd, Centre for Metrology MIKES, a pressure pulse is generated by impact between a dropping weight and a piston of a liquid-filled piston-cylinder assembly. The traceability to SI-units is realized through interferometric measurement of the acceleration of the dropping weight during impact, the effective area of the piston-cylinder assembly and the mass of the weight. Based on experimental validation and an uncertainty evaluation, the developed primary standard provides traceability for peak pressures in the range from 10 MPa to 400 MPa with a few millisecond pulse width and a typical relative expanded uncertainty (k  =  2) of 1.5%. The performance of the primary standard is demonstrated by test calibrations of two dynamic pressure transducers.

Characterization and Uncertainty Analysis of a Reference Pressure Measurement System for Wind Tunnels

NASA Technical Reports Server (NTRS)

Amer, Tahani; Tripp, John; Tcheng, Ping; Burkett, Cecil; Sealey, Bradley

2004-01-01

This paper presents the calibration results and uncertainty analysis of a high-precision reference pressure measurement system currently used in wind tunnels at the NASA Langley Research Center (LaRC). Sensors, calibration standards, and measurement instruments are subject to errors due to aging, drift with time, environment effects, transportation, the mathematical model, the calibration experimental design, and other factors. Errors occur at every link in the chain of measurements and data reduction from the sensor to the final computed results. At each link of the chain, bias and precision uncertainties must be separately estimated for facility use, and are combined to produce overall calibration and prediction confidence intervals for the instrument, typically at a 95% confidence level. The uncertainty analysis and calibration experimental designs used herein, based on techniques developed at LaRC, employ replicated experimental designs for efficiency, separate estimation of bias and precision uncertainties, and detection of significant parameter drift with time. Final results, including calibration confidence intervals and prediction intervals given as functions of the applied inputs, not as a fixed percentage of the full-scale value are presented. System uncertainties are propagated beginning with the initial reference pressure standard, to the calibrated instrument as a working standard in the facility. Among the several parameters that can affect the overall results are operating temperature, atmospheric pressure, humidity, and facility vibration. Effects of factors such as initial zeroing and temperature are investigated. The effects of the identified parameters on system performance and accuracy are discussed.

Cape Canaveral, Florida range reference atmosphere 0-70 km altitude

NASA Technical Reports Server (NTRS)

Tingle, A. (Editor)

1983-01-01

The RRA contains tabulations for monthly and annual means, standard deviations, skewness coefficients for wind speed, pressure temperature, density, water vapor pressure, virtual temperature, dew-point temperature, and the means and standard deviations for the zonal and meridional wind components and the linear (product moment) correlation coefficient between the wind components. These statistical parameters are tabulated at the station elevation and at 1 km intervals from sea level to 30 km and at 2 km intervals from 30 to 90 km altitude. The wind statistics are given at approximately 10 m above the station elevations and at altitudes with respect to mean sea level thereafter. For those range sites without rocketsonde measurements, the RRAs terminate at 30 km altitude or they are extended, if required, when rocketsonde data from a nearby launch site are available. There are four sets of tables for each of the 12 monthly reference periods and the annual reference period.

10 CFR 431.76 - Uniform test method for the measurement of energy efficiency of commercial warm air furnaces.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Gases), 2.5 (Test Pressures and Burner Adjustments), 2.6 (Static Pressure and Air Flow Adjustments), 2... pressure, as specified in Section 2.5.1 of ANSI Standard Z21.47-1998, (Incorporated by reference, see § 431... thermal efficiency test), 41 (Initial Test Conditions), 42 (Combustion Test—Burner and Furnace), 43.2...

10 CFR 431.76 - Uniform test method for the measurement of energy efficiency of commercial warm air furnaces.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Gases), 2.5 (Test Pressures and Burner Adjustments), 2.6 (Static Pressure and Air Flow Adjustments), 2... pressure, as specified in Section 2.5.1 of ANSI Standard Z21.47-1998, (Incorporated by reference, see § 431... thermal efficiency test), 41 (Initial Test Conditions), 42 (Combustion Test—Burner and Furnace), 43.2...

Final report on EURAMET.M.P-K4.2010: Key and supplementary comparison of national pressure standards in the range 1 Pa to 15 kPa of absolute and gauge pressure

NASA Astrophysics Data System (ADS)

Krajíček, Zdeněk; Bergoglio, Mercede; Jousten, Karl; Otal, Pierre; Sabuga, Wladimir; Saxholm, Sari; Pražák, Dominik; Vičar, Martin

2014-01-01

This report describes a EURAMET comparison of five European National Metrology Institutes in low gauge and absolute pressure in gas (nitrogen), denoted as EURAMET.M.P-K4.2010. Its main intention is to state equivalence of the pressure standards, in particular those based on the technology of force-balanced piston gauges such as e.g. FRS by Furness Controls, UK and FPG8601 by DHI-Fluke, USA. It covers the range from 1 Pa to 15 kPa, both gauge and absolute. The comparison in absolute mode serves as a EURAMET Key Comparison which can be linked to CCM.P-K4 and CCM.P-K2 via PTB. The comparison in gauge mode is a supplementary comparison. The comparison was carried out from September 2008 till October 2012. The participating laboratories were the following: CMI, INRIM, LNE, MIKES, PTB-Berlin (absolute pressure 1 kPa and below) and PTB-Braunschweig (absolute pressure 1 kPa and above and gauge pressure). CMI was the pilot laboratory and provided a transfer standard for the comparison. This transfer standard was also the laboratory standard of CMI at the same time, which resulted in a unique and logistically difficult star comparison. Both in gauge and absolute pressures all the participating institutes successfully proved their equivalence with respect to the reference value and all also proved mutual bilateral equivalences in all the points. All the participating laboratories are also equivalent with the reference values of CCM.P-K4 and CCM.P-K2 in the relevant points. The comparison also proved the ability of FPG8601 to serve as a transfer standard. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

High precision UTDR measurements by sonic velocity compensation with reference transducer.

PubMed

Stade, Sam; Kallioinen, Mari; Mänttäri, Mika; Tuuva, Tuure

2014-07-02

An ultrasonic sensor design with sonic velocity compensation is developed to improve the accuracy of distance measurement in membrane modules. High accuracy real-time distance measurements are needed in membrane fouling and compaction studies. The benefits of the sonic velocity compensation with a reference transducer are compared to the sonic velocity calculated with the measured temperature and pressure using the model by Belogol'skii, Sekoyan et al. In the experiments the temperature was changed from 25 to 60 °C at pressures of 0.1, 0.3 and 0.5 MPa. The set measurement distance was 17.8 mm. Distance measurements with sonic velocity compensation were over ten times more accurate than the ones calculated based on the model. Using the reference transducer measured sonic velocity, the standard deviations for the distance measurements varied from 0.6 to 2.0 µm, while using the calculated sonic velocity the standard deviations were 21-39 µm. In industrial liquors, not only the temperature and the pressure, which were studied in this paper, but also the properties of the filtered solution, such as solute concentration, density, viscosity, etc., may vary greatly, leading to inaccuracy in the use of the Belogol'skii, Sekoyan et al. model. Therefore, calibration of the sonic velocity with reference transducers is needed for accurate distance measurements.

[Implementation of the National Expert Standard Prophylaxis of Pressure Ulcers in nurse practise - a cost-benefit analysis].

PubMed

Wolke, R; Hennings, D; Scheu, P

2007-06-01

By developing evidence-based, national Expert Standards, agreed-upon by an association of nursing professionals, the German Care Science participates in the international discussion. Up to now, five National Expert Standards on relevant care-related topics have been developed and have been widely implemented in Care Practice. However, sufficient evaluations of these Expert Standards are still required, especially from an economic perspective. The following paper addresses this topic by performing a cost-benefit analysis for the National Expert Standard Prophylaxis of Pressure Ulcers. The authors demonstrate which costs are caused by the implementation of this National Expert Standard for a residential care agency providing services. The benefit of the implementation of the Expert Standard is then being compared to its cost for a period of three years. The evaluation concludes that, in consideration of opportunity costs, the introduction of the National Expert Standard Prophylaxis of Pressure Ulcers appears economically viable for the residential care agency only if the rate of pressure ulcers in the reference agency can be lowered at least by 26.48%. In this case, when exclusively considering direct benefits and direct costs, a positive impact of the implementation will be achieved.

New Standards for Diagnosing Hypertension Are Met with Skepticism | Poster

Cancer.gov

Members of the Eighth Joint National Committee recently released new standards for treating hypertension, also referred to as high blood pressure (BP). The new standards do not recommend treatment changes for individuals under 60 years of age. However, treatment changes were recommended for people over the age of 60 who do not have conditions such as diabetes or chronic kidney

KEY COMPARISON: Results of the APMP Pressure key comparison APMP.M.P-K1c in gas media and gauge mode from 0.4 MPa to 4.0 MPa

NASA Astrophysics Data System (ADS)

Bandyopadhyay, A. K.; Woo, Sam Yong; Fitzgerald, Mark; Man, John; Ooiwa, Akira; Jescheck, M.; Jian, Wu; Fatt, Chen Soo; Chan, T. K.; Moore, Ken; El-Tawil, Alaaeldin A. E.

2003-01-01

This report summarizes the results of a regional key comparison (APMP-IC-2-97) under the aegis of the Asia Pacific Metrology Program (APMP) for pressure measurements in gas media and in gauge mode from 0.4 MPa to 4.0 MPa. The transfer standard was a pressure-balance with a piston-cylinder assembly with nominal effective area 8.4 mm2 (V-407) and was supplied by the National Metrology Institute of Japan [NMIJ]. Ten standard laboratories from the APMP region with one specially invited laboratory from the EUROMET region, namely Physikalisch-Technische Bundesanstalt (PTB), Germany, participated in this comparison. The comparison started in October 1998 and was completed in May 2001. The pilot laboratory prepared the calibration procedure [1] as per the guidelines of APMP and the International Bureau of Weights and Measures (BIPM) [2-4]. Detailed instructions for performing this key comparison were provided in the calibration protocol [1] and the required data were described in: (1) Annex 3 - characteristics of the laboratory standards, (2) Annex 4 - the effective area (A'p'/mm2) (the prime indicates values based on measured quantities) at 23°C of the travelling standard as a function of nominal pressure (p'/MPa) (five cycles both increasing and decreasing pressures at ten pre-determined pressure points) and (3) Annex 5 - the average effective area at 23°C (A'p'/mm2) obtained for each pressure p'/MPa with all uncertainty statements. The pilot laboratory processed the information and the data provided by the participants for these three annexes, starting with the information about the standards as provided in Annex 3. Based on this information, the participating laboratories are classified into two categories: (I) laboratories that are maintaining primary standards, and (II) laboratories that are maintaining standards loosely classified as secondary standards with a clear traceability as per norm of the BIPM. It is observed that out of these eleven laboratories, six laboratories have primary standards [Category (I)], the remaining five laboratories are placed in Category (II). The obtained data were compiled and processed under the same program as per the Consultative Committee for Mass and Related Quantities (CCM)/BIPM guidelines. From the data of Category (I), we evaluated the APMP reference value as a function of p'/MPa. Then, we estimated the relative difference of the A'p' values with reference to the APMP reference value for all participating laboratories and we observed that they agree well within their expanded uncertainties. We further estimated the effective area at null pressure and at 23°C (A'0/mm2) and the pressure distortion coefficient (lambda'/MPa-1) of the transfer standard for all the participating laboratories. We then estimated the relative deviation of the A'0/mm2 from the reference value for all eleven laboratories and compared this with their estimated expanded uncertainties. The result is once again extremely encouraging and all these eleven laboratories are agreeing within their estimated maximum expanded uncertainties. We also estimated the degree of equivalence between any two participating laboratories following a matrix mechanism. This once again agrees extremely well within the estimated relative standard uncertainty, which is derived for the two participating laboratories. Finally, a new method has been introduced to evaluate these results and establish a link to CCM.P-K1c and EUROMET.M.P-K2 at two nominal pressures, near 1 MPa and 4 MPa. Again the results show an agreement of all participating laboratories in the present comparison to within the estimated expanded uncertainties using a coverage factor k = 2. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the APMP, according to the provisions of the Mutual Recognition Arrangement (MRA).

Noninvasive monitoring of blood pressure using optical Ballistocardiography and Photoplethysmograph approaches.

PubMed

Chen, Zhihao; Yang, Xiufeng; Teo, Ju Teng; Ng, Soon Huat

2013-01-01

A new all optical method for long term and continuous blood pressure measurement and monitoring without using cuffs is proposed by using Ballistocardiography (BCG) and Photoplethysmograph (PPG). Based on BCG signal and PPG signal, a time delay between these two signals is obtained to calculate both systolic blood pressure and diastolic blood pressure via linear regression analysis. The fabricated noninvasive blood pressure monitoring device consists of a fiber sensor mat to measure BCG signal and a SpO2 sensor to measure PPG signal. A commercial digital oscillometric blood pressure meter is used to obtain reference values and for calibration. It has been found that by comparing with the reference device, our prototype has typical means and standard deviations of 9+/-5.6 mmHg for systolic blood pressure, 1.8+/-1.3 mmHg for diastolic blood pressure and 0.6+/-0.9 bpm for pulse rate, respectively. If the fiber optic SpO2 probe is used, this new all fiber cuffless noninvasive blood pressure monitoring device will truly be a MRI safe blood pressure measurement and monitoring device.

49 CFR 195.3 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Fittings Industry, Inc. (MSS), 127 Park Street, NE., Vienna, VA 22180. 5. American Society for Testing and...)) §§ 195.205(b)(1); 195.432(b). (12) API Standard 1104, “Welding of Pipelines and Related Facilities” (20th....307(e). (7) 2007 ASME Boiler & Pressure Vessel Code, Section IX: “Qualification Standard for Welding...

Frequency analysis of a step dynamic pressure calibrator.

PubMed

Choi, In-Mook; Yang, Inseok; Yang, Tae-Heon

2012-09-01

A dynamic high pressure standard is becoming more essential in the fields of mobile engines, space science, and especially the area of defense such as long-range missile development. However, a complication arises when a dynamic high pressure sensor is compared with a reference dynamic pressure gauge calibrated in static mode. Also, it is difficult to determine a reference dynamic pressure signal from the calibrator because a dynamic high pressure calibrator generates unnecessary oscillations in a positive-going pressure step method. A dynamic high pressure calibrator, using a quick-opening ball valve, generates a fast step pressure change within 1 ms; however, the calibrator also generates a big impulse force that can lead to a short life-time of the system and to oscillating characteristics in response to the dynamic sensor to be calibrated. In this paper, unnecessary additional resonant frequencies besides those of the step function are characterized using frequency analysis. Accordingly, the main sources of resonance are described. In order to remove unnecessary frequencies, the post processing results, obtained by a filter, are given; also, a method for the modification of the dynamic calibration system is proposed.

Frequency analysis of a step dynamic pressure calibrator

NASA Astrophysics Data System (ADS)

Choi, In-Mook; Yang, Inseok; Yang, Tae-Heon

2012-09-01

A dynamic high pressure standard is becoming more essential in the fields of mobile engines, space science, and especially the area of defense such as long-range missile development. However, a complication arises when a dynamic high pressure sensor is compared with a reference dynamic pressure gauge calibrated in static mode. Also, it is difficult to determine a reference dynamic pressure signal from the calibrator because a dynamic high pressure calibrator generates unnecessary oscillations in a positive-going pressure step method. A dynamic high pressure calibrator, using a quick-opening ball valve, generates a fast step pressure change within 1 ms; however, the calibrator also generates a big impulse force that can lead to a short life-time of the system and to oscillating characteristics in response to the dynamic sensor to be calibrated. In this paper, unnecessary additional resonant frequencies besides those of the step function are characterized using frequency analysis. Accordingly, the main sources of resonance are described. In order to remove unnecessary frequencies, the post processing results, obtained by a filter, are given; also, a method for the modification of the dynamic calibration system is proposed.

EURAMET.M.P-S9 / EURAMET 1170, LOOP2. Comparison in the negative gauge pressure range -950 to 0 hPa

NASA Astrophysics Data System (ADS)

Otal, P.; Boineau, F.; Medina, N.; Pražák, D.; Wüthrich, C.; Saxholm, S.; Sabuga, W.; Kocas, I.; Durgut, Y.

2017-01-01

This report gives the results of a comparison of pressure standards of seven European National Metrology institutes in the range of negative gauge pressure from -950 hPa to 0 hPa. This comparison was piloted by LNE and was carried out from January 2011 to March 2012. This work is a part of the EURAMET project 1170 and is registered as a supplementary comparison EURAMET.M.P-S9. The transfer standard used was a pressure monitor RPM4 A160Ks manufactured by DH Instruments Inc., with a resolution of 0.1 Pa. The reference values have been determined from the weighted mean of the deviations reported by the participants for each specified pressure. Seventy-three of the seventy-seven values (96%) reported by the laboratories agree with the reference values within the expanded uncertainties with a coverage factor k = 2. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

49 CFR 192.7 - What documents are incorporated by reference partly or wholly in this part?

Code of Federal Regulations, 2013 CFR

2013-10-01

... for Seamless Carbon Steel Pipe for High-Temperature Service” (July 15, 2008) §§ 192.113; Item I... Metal-Arc Welded Steel Pipe for Use With High-Pressure Transmission Systems” (October 1, 2005) §§ 192...) ASTM A672-08, “Standard Specification for Electric-Fusion-Welded Steel Pipe for High-Pressure Service...

49 CFR 192.7 - What documents are incorporated by reference partly or wholly in this part?

Code of Federal Regulations, 2014 CFR

2014-10-01

... for Seamless Carbon Steel Pipe for High-Temperature Service” (July 15, 2008) §§ 192.113; Item I... Metal-Arc Welded Steel Pipe for Use With High-Pressure Transmission Systems” (October 1, 2005) §§ 192...) ASTM A672-08, “Standard Specification for Electric-Fusion-Welded Steel Pipe for High-Pressure Service...

49 CFR 192.7 - What documents are incorporated by reference partly or wholly in this part?

Code of Federal Regulations, 2012 CFR

2012-10-01

... for Seamless Carbon Steel Pipe for High-Temperature Service” (July 15, 2008) §§ 192.113; Item I... Metal-Arc Welded Steel Pipe for Use With High-Pressure Transmission Systems” (October 1, 2005) §§ 192...) ASTM A672-08, “Standard Specification for Electric-Fusion-Welded Steel Pipe for High-Pressure Service...

Development of liquid chromatographic methods for the determination of phytosterols in Standard Reference Materials containing saw palmetto.

PubMed

Bedner, Mary; Schantz, Michele M; Sander, Lane C; Sharpless, Katherine E

2008-05-23

Liquid chromatographic (LC) methods using atmospheric pressure chemical ionization/mass spectrometric (APCI-MS) detection were developed for the separation and analysis of the phytosterols campesterol, cycloartenol, lupenone, lupeol, beta-sitosterol, and stigmasterol. Brassicasterol and cholesterol were also included for investigation as internal standards. The methods were used to identify and quantify the phytosterols in each of two Serenoa repens (saw palmetto) Standard Reference Materials (SRMs) developed by the National Institute of Standards and Technology (NIST). Values obtained by LC-MS were compared to those obtained using the more traditional approach of gas chromatography with flame ionization detection. This is the first reported use of LC-MS to determine phytosterols in saw palmetto dietary supplement materials.

46 CFR 30.01-3 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, telephone 610-832-9585, http://www.astm.org. (1) ASTM D 323-94, Standard Test Method for Vapor Pressure of Petroleum Products...

46 CFR 162.017-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Standardization (ISO), Case postal 56, CH-1211 Geneva 20, Switzerland: (1) ISO 15364, Ships and Marine Technology—Pressure/Vacuum Valves for Cargo Tanks, First Edition (Sep. 1, 2000) (“ISO 15364”), 162.017-3; and (2...

46 CFR 162.017-1 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Standardization (ISO), Case postal 56, CH-1211 Geneva 20, Switzerland: (1) ISO 15364, Ships and Marine Technology—Pressure/Vacuum Valves for Cargo Tanks, First Edition (Sep. 1, 2000) (“ISO 15364”), 162.017-3; and (2...

46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... described in the American Society for Testing Materials Standard D 323 (incorporated by reference, see § 30... Headquarters for reading purposes or it may be purchased from the Society at 100 Barr Harbor Drive, West...

Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

PubMed

Nelson, Bryant C; Sharpless, Katherine E

2003-01-29

Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.

Validation of the Artsana CSI 610 automated blood pressure monitor in adults according to the International Protocol of the European Society of Hypertension.

PubMed

Pini, Claudio; Pastori, Marco; Baccheschi, Jordan; Omboni, Stefano; Parati, Gianfranco

2007-06-01

There is evidence that blood pressure measurement outside the doctor's office can provide valuable information for the diagnostic evaluation of hypertensive patients and for monitoring their response to treatment. Home blood pressure monitoring devices have a major role in this setting, provided that their accuracy in measuring blood pressure is demonstrated by validation studies. This study aimed at verifying whether the automatic electronic oscillometric blood pressure measuring device Artsana CSI 610 complied with the standard of accuracy indicated by the ESH International Protocol. Sequential measurements of systolic and diastolic blood pressure were obtained in 33 participants using the mercury sphygmomanometer (two observers) and the test device (one supervisor). A standard adult cuff was always employed during the study. According to the ESH validation protocol, 99 couples of test device and reference blood pressure measurements were obtained during the two phases of the study (three pairs for each of the 33 participants). The Artsana CSI 610 device successfully passed phase 1 of study validation with the number of absolute differences between test and reference device never <35 within 5 mmHg and never <40 within 10 and 15 mmHg. The test device also passed phase 2 of the validation study with a mean (+/-SD) device-observer difference of -1.4+/-4.8 mmHg for systolic and -0.9+/-3.5 mmHg for diastolic blood pressure. According to the results of the validation study on the basis of the ESH International Protocol, the Artsana CSI 610 can be recommended for clinical use in adults.

Unsteady Cascade Aerodynamic Response Using a Multiphysics Simulation Code

NASA Technical Reports Server (NTRS)

Lawrence, C.; Reddy, T. S. R.; Spyropoulos, E.

2000-01-01

The multiphysics code Spectrum(TM) is applied to calculate the unsteady aerodynamic pressures of oscillating cascade of airfoils representing a blade row of a turbomachinery component. Multiphysics simulation is based on a single computational framework for the modeling of multiple interacting physical phenomena, in the present case being between fluids and structures. Interaction constraints are enforced in a fully coupled manner using the augmented-Lagrangian method. The arbitrary Lagrangian-Eulerian method is utilized to account for deformable fluid domains resulting from blade motions. Unsteady pressures are calculated for a cascade designated as the tenth standard, and undergoing plunging and pitching oscillations. The predicted unsteady pressures are compared with those obtained from an unsteady Euler co-de refer-red in the literature. The Spectrum(TM) code predictions showed good correlation for the cases considered.

Comparison of the oscillometric blood pressure monitor (BPM-100(Beta) ) with the auscultatory mercury sphygmomanometer.

PubMed

Mattu, G S; Perry, T L; Wright, J M

2001-06-01

To compare directly the accuracy of the BPM-100(Beta) monitor (an automated oscillometric blood pressure device) with standard auscultatory mercury sphygmomanometry. The BPM-100(Beta) was connected in parallel via a T-tube to a mercury sphygmomanometer. The BPM-100(Beta) and two trained observers (blinded from each other and from the BPM-100(Beta)) measured the sitting blood pressure simultaneously. Means, standard deviations and ranges were calculated for all the demographic data: age, arm size, heart rate and blood pressure. The agreement between the BPM-100(Beta) and the mean of two observers (the reference) was determined and expressed as the mean +/- SD, as well as the percentage of differences falling within 5, 10 and 15 mmHg. Of the 92 subjects recruited, 85 (92.4%) met the inclusion criteria, and 391 sets of sitting blood pressure and heart rate measurements were available for analysis. The mean difference between the BPM-100(Beta) monitor and the reference was -0.62 +/- 6.96 mmHg for systolic blood pressure, -1.48 +/- 4.80 mmHg for diastolic blood pressure and 0.14 +/- 1.86 beats/min for heart rate. The only limitation of the device was its tendency to underestimate higher systolic blood pressures. This problem has been addressed by a minor change in the algorithm (see the companion publication, Blood Press Monit, 6, 161-165, 2001). The BPM-100(Beta) is an accurate blood pressure monitor for the office setting, meeting all requirements of the Association for the Advancement of Medical Instrumentation and achieving an 'A' grade according to the British Hypertension Society protocol.

Comparison in gas media (absolute and gauge mode)in the range from 25 kPa TO 200 kPa (EURAMET.M.P-K8)

NASA Astrophysics Data System (ADS)

Wuethrich, C.; Alisic, S.; Altintas, A.; van Andel, I.; C, In­Mook; Eltawil, A. A.; Farár, P.; Hetherington, P.; Koçaş, I.; Lefkopoulos, A.; Otal, P.; Prazak, D.; Sabuga, W.; Salustiano, R.; Sandu, I.; Sardi, M.; Saxholm, S.; Setina, J.; Spohr, I.; Steindl, D.; Testa, N.; Vámossy, C.; Grgec Bermanec, L.

2016-01-01

It was decided at the EURAMET TC-M meeting in Torino in 2006 to realize a comparison in gauge and absolute pressure up to 200 kPa as it would allow a link to the CCM.P-K6 and CCM.P-K2 comparisons to be established. This project interested a lot of laboratories from the beginning with 23 participants, 22 of which have submitted results. The circulation of the transfer standard began in July 2009 and lasted until January 2012. No major problems occurred during the transport. The measurand of the comparison is the effective area of a piston-cylinder determined in gauge and absolute pressure from 25 kPa to 200 kPa with pressure steps of 25 kPa. The transfer standard is a gas lubricated tungsten carbide piston-cylinder with an effective area of ~9.8 cm2, fabricated by DH Instruments and compatible with a PG-7601 pressure balance. Some participants used their own pressure balance while a pressure balance with a reference vacuum sensor has been circulated for the participants not equipped with this system. One participant (SMU, Slovakia) has never provided the measurement results and another participant (FORCE Technology, Denmark) submitted a revised set of measurement results after the pilot laboratory mentioned that the equivalence was not met. After the determination of the reference value, all the 22 participants who delivered the results in gauge pressure demonstrated equivalence respective to the reference value on most of the range. In absolute pressure the equivalence is demonstrated, for all nominal pressures, by all 17 participants who submitted results. The comparison is linked to the CCM.P-K6 for gauge pressure and to CCM.P-K2 for absolute pressure. The link does not strongly affect the equivalence of the results and an excellent degree of equivalence is achieved in gauge and absolute pressure. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

49 CFR 195.264 - Impoundment, protection against entry, normal/emergency venting or pressure/vacuum relief for...

Code of Federal Regulations, 2014 CFR

2014-10-01

... specified: (1) For tanks built to API Specification 12F, API Standard 620, and others (such as API Standard... accordance with section 4.3.2.3.1. (2) For tanks built to API 2510, the installation of impoundment must be in accordance with section 5 or 11 of API 2510 (incorporated by reference, see § 195.3). (c...

49 CFR 195.264 - Impoundment, protection against entry, normal/emergency venting or pressure/vacuum relief for...

Code of Federal Regulations, 2012 CFR

2012-10-01

... specified: (1) For tanks built to API Specification 12F, API Standard 620, and others (such as API Standard... accordance with section 4.3.2.3.1. (2) For tanks built to API 2510, the installation of impoundment must be in accordance with section 5 or 11 of API 2510 (incorporated by reference, see § 195.3). (c...

49 CFR 195.264 - Impoundment, protection against entry, normal/emergency venting or pressure/vacuum relief for...

Code of Federal Regulations, 2013 CFR

2013-10-01

... specified: (1) For tanks built to API Specification 12F, API Standard 620, and others (such as API Standard... accordance with section 4.3.2.3.1. (2) For tanks built to API 2510, the installation of impoundment must be in accordance with section 5 or 11 of API 2510 (incorporated by reference, see § 195.3). (c...

49 CFR 195.264 - Impoundment, protection against entry, normal/emergency venting or pressure/vacuum relief for...

Code of Federal Regulations, 2011 CFR

2011-10-01

... specified: (1) For tanks built to API Specification 12F, API Standard 620, and others (such as API Standard... accordance with section 4.3.2.3.1. (2) For tanks built to API 2510, the installation of impoundment must be in accordance with section 5 or 11 of API 2510 (incorporated by reference, see § 195.3). (c...

Pressurized liquid extraction of diesel and air particulate standard reference materials: effect of extraction temperature and pressure.

PubMed

Schantz, Michele M; McGaw, Elizabeth; Wise, Stephen A

2012-10-02

Four particulate matter Standard Reference Materials (SRMs) available from the National Institute of Standards and Technology (NIST) were used to evaluate the effect of solvent, number of static cycles and static times, pressure, and temperature when using pressurized liquid extraction (PLE) for the extraction of polycyclic aromatic hydrocarbons (PAHs) and nitrated-PAHs. The four materials used in the study were SRM 1648a Urban Particulate Matter, SRM 1649b Urban Dust, SRM 1650b Diesel Particulate Matter, and SRM 2975 Diesel Particulate Matter (Industrial Forklift). The results from the study indicate that the choice of solvent, dichloromethane compared to toluene and toluene/methanol mixtures, had little effect on the extraction efficiency. With three to five extraction cycles, increasing the extraction time for each cycle from 5 to 30 min had no significant effect on the extraction efficiency. The differences in extraction efficiency were not significant (with over 95% of the differences being <10%) when the pressure was increased from 13.8 to 20.7 MPa. The largest increase in extraction efficiency occurred for selected PAHs when the temperature of extraction was increased from 100 to 200 °C. At 200 °C naphthalene, biphenyl, fluorene, dibenzothiophene, and anthracene show substantially higher mass fractions (>30%) than when extracted at 100 °C in all the SRMs studied. For SRM 2975, large increases (>100%) are also observed for some other PAHs including benz[a]anthracene, benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, benzo[ghi]perylene, and benzo[b]chrysene when extracted at the higher temperatures; however, similar trends were not observed for the other diesel particulate sample, SRM 1650b. The results are discussed in relation to the use of the SRMs for evaluating analytical methods.

Determination of vapor pressures for nonpolar and semipolar organic compounds from gas chromatographic retention data

USGS Publications Warehouse

Hinckley, D.A.; Bidleman, T.F.; Foreman, W.T.; Tuschall, J.R.

1990-01-01

Vapor pressures for nonpolar and moderately polar organochlorine, pyrethroid, and organophosphate insecticides, phthalate esters, and organophosphate flame retardants were determined by capillary gas chromatography (GC). Organochlorines and polycyclic aromatic hydrocarbons with known liquid-phase vapor pressures (P??L) (standard compounds) were chromatographed along with two reference compounds n-C20 (elcosane) and p,p???-DDT on a 1.0-m-long poly(dimethylsiloxane) bonded-phase (BP-1) column to determine their vapor pressures by GC (P??GC). A plot of log P??L vs log P??GC for standard compounds was made to establish a correlation between measured and literature values, and this correlation was then used to compute P??L of test compounds from their measured P??GC. P??L of seven major components of technical chlordane, endosulfan and its metabolites, ??-hexachlorocyclohexane, mirex, and two components of technical toxaphene were determined by GC. This method provides vapor pressures within a factor of 2 of average literature values for nonpolar compounds, similar to reported interlaboratory precisions of vapor pressure determinations. GC tends to overestimate vapor pressures of moderately polar compounds. ?? 1990 American Chemical Society.

A National Trial on Differences in Cerebral Perfusion Pressure Values by Measurement Location.

PubMed

McNett, Molly M; Bader, Mary Kay; Livesay, Sarah; Yeager, Susan; Moran, Cristina; Barnes, Arianna; Harrison, Kimberly R; Olson, DaiWai M

2018-04-01

Cerebral perfusion pressure (CPP) is a key parameter in management of brain injury with suspected impaired cerebral autoregulation. CPP is calculated by subtracting intracranial pressure (ICP) from mean arterial pressure (MAP). Despite consensus on importance of CPP monitoring, substantial variations exist on anatomical reference points used to measure arterial MAP when calculating CPP. This study aimed to identify differences in CPP values based on measurement location when using phlebostatic axis (PA) or tragus (Tg) as anatomical reference points. The secondary study aim was to determine impact of differences on patient outcomes at discharge. This was a prospective, repeated measures, multi-site national trial. Adult ICU patients with neurological injury necessitating ICP and CPP monitoring were consecutively enrolled from seven sites. Daily MAP/ICP/CPP values were gathered with the arterial transducer at the PA, followed by the Tg as anatomical reference points. A total of 136 subjects were enrolled, resulting in 324 paired observations. There were significant differences for CPP when comparing values obtained at PA and Tg reference points (p < 0.000). Differences remained significant in repeated measures model when controlling for clinical factors (mean CPP-PA = 80.77, mean CPP-Tg = 70.61, p < 0.000). When categorizing CPP as binary endpoint, 18.8% of values were identified as adequate with PA values, yet inadequate with CPP values measured at the Tg. Findings identify numerical differences for CPP based on anatomical reference location and highlight importance of a standard reference point for both clinical practice and future trials to limit practice variations and heterogeneity of findings.

Improved pressure measurement system for calibration of the NASA LeRC 10x10 supersonic wind tunnel

NASA Technical Reports Server (NTRS)

Blumenthal, Philip Z.; Helland, Stephen M.

1994-01-01

This paper discusses a method used to provide a significant improvement in the accuracy of the Electronically Scanned Pressure (ESP) Measurement System by means of a fully automatic floating pressure generating system for the ESP calibration and reference pressures. This system was used to obtain test section Mach number and flow angularity measurements over the full envelope of test conditions for the 10 x 10 Supersonic Wind Tunnel. The uncertainty analysis and actual test data demonstrated that, for most test conditions, this method could reduce errors to about one-third to one-half that obtained with the standard system.

Long-life leak standard assembly

DOEpatents

Basford, James A.; Mathis, John E.; Wright, Harlan C.

1982-01-01

The present invention is directed to a portable leak standard assembly which is capable of providing a stream of high-purity reference gas at a virtually constant flow rate over an extensive period of time. The leak assembly comprises a high pressure reservoir coupled to a metal leak valve through a valve-controlled conduit. A reproducible leak valve useful in this assembly is provided by a metal tube crimped with a selected pressure loading for forming an orifice in the tube with this orifice being of a sufficient size to provide the selected flow rate. The leak valve assembly is formed of metal so that it can be "baked-out" in a vacuum furnace to rid the reservoir and attendent components of volatile impurities which reduce the efficiency of the leak standard.

Long-life leak standard assembly. [Patent application

DOEpatents

Basford, J.A.; Mathis, J.E.; Wright, H.C.

1980-11-12

The present invention is directed to a portable leak standard assembly which is capable of providing a stream of high-purity reference gas at a virtually constant flow rate over an extensive period of time. The leak assembly comprises a high pressure reservoir coupled to a metal leak valve through a valve-controlled conduit. A reproducible leak valve useful in this assembly is provided by a metal tube crimped with a selected pressure loading for forming an orifice in the tube with this orifice being of a sufficient size to provide the selected flow rate. The leak valve assembly is formed of metal so that it can be baked-out in a vacuum furnace to rid the reservoir and attendent components of volatile impurities which reduce the efficiency of the leak standard.

Prediction equations for maximal respiratory pressures of Brazilian adolescents.

PubMed

Mendes, Raquel E F; Campos, Tania F; Macêdo, Thalita M F; Borja, Raíssa O; Parreira, Verônica F; Mendonça, Karla M P P

2013-01-01

The literature emphasizes the need for studies to provide reference values and equations able to predict respiratory muscle strength of Brazilian subjects at different ages and from different regions of Brazil. To develop prediction equations for maximal respiratory pressures (MRP) of Brazilian adolescents. In total, 182 healthy adolescents (98 boys and 84 girls) aged between 12 and 18 years, enrolled in public and private schools in the city of Natal-RN, were evaluated using an MVD300 digital manometer (Globalmed®) according to a standardized protocol. Statistical analysis was performed using SPSS Statistics 17.0 software, with a significance level of 5%. Data normality was verified using the Kolmogorov-Smirnov test, and descriptive analysis results were expressed as the mean and standard deviation. To verify the correlation between the MRP and the independent variables (age, weight, height and sex), the Pearson correlation test was used. To obtain the prediction equations, stepwise multiple linear regression was used. The variables height, weight and sex were correlated to MRP. However, weight and sex explained part of the variability of MRP, and the regression analysis in this study indicated that these variables contributed significantly in predicting maximal inspiratory pressure, and only sex contributed significantly to maximal expiratory pressure. This study provides reference values and two models of prediction equations for maximal inspiratory and expiratory pressures and sets the necessary normal lower limits for the assessment of the respiratory muscle strength of Brazilian adolescents.

Can we trust intraocular pressure measurements in eyes with intracameral air?

PubMed

Jóhannesson, Gauti; Lindén, Christina; Eklund, Anders; Behndig, Anders; Hallberg, Per

2014-10-01

To evaluate the effect of intracameral air on intraocular pressure (IOP) measurements using Goldmann applanation tonometry (GAT) and applanation resonance tonometry (ART) in an in-vitro porcine eye model. IOP was measured on thirteen freshly enucleated eyes at three reference pressures: 20, 30, and 40 mmHg. Six measurements/method were performed in a standardized order with GAT and ART respectively. Air was injected intracamerally in the same manner as during Descemet's stripping endothelial keratoplasty (DSEK) and Descemet's membrane endothelial keratoplasty (DMEK), and the measurements were repeated. Measured IOP increased significantly for both tonometry methods after air injection: 0.7 ± 2.1 mmHg for GAT and 10.6 ± 4.9 mmHg for ART. This difference was significant at each reference pressure for ART but not for GAT. Although slightly affected, this study suggests that we can trust GAT IOP-measurements in eyes with intracameral air, such as after DSEK/DMEK operations. Ultrasound-based methods such as ART should not be used.

Final Report on the Key Comparison CCM.P-K4.2012 in Absolute Pressure from 1 Pa to 10 kPa

PubMed Central

Ricker, Jacob; Hendricks, Jay; Bock, Thomas; Dominik, Pražák; Kobata, Tokihiko; Torres, Jorge; Sadkovskaya, Irina

2017-01-01

The report summarizes the Consultative Committee for Mass (CCM) key comparison CCM.P-K4.2012 for absolute pressure spanning the range of 1 Pa to 10 000 Pa. The comparison was carried out at six National Metrology Institutes (NMIs), including National Institute of Standards and Technology (NIST), Physikalisch-Technische Bundesanstalt (PTB), Czech Metrology Institute (CMI), National Metrology Institute of Japan (NMIJ), Centro Nacional de Metrología (CENAM), and DI Mendeleyev Institute for Metrology (VNIIM). The comparison was made via a calibrated transfer standard measured at each of the NMIs facilities using their laboratory standard during the period May 2012 to September 2013. The transfer package constructed for this comparison preformed as designed and provided a stable artifact to compare laboratory standards. Overall the participants were found to be statistically equivalent to the key comparison reference value. PMID:28216793

UV emissions from artificial tanning devices and their compliance with the European technical standard.

PubMed

Facta, Stefania; Fusette, Stefania Saudino; Bonino, Alessandro; Anglesio, Laura; d'Amore, Giovanni

2013-04-01

Use of ultraviolet radiation-emitting tanning devices has been classified as "carcinogenic to humans" (group 1) by the International Agency for Research on Cancer. Following this classification, the knowledge of typical ultraviolet emission levels from tanning devices can be of interest for evaluating their impact on health. In this work, the results of an extensive measurement campaign on artificial tanning appliances are presented. Ultraviolet emissions from 94 tanning appliances produced by 15 different manufacturers were characterized by onsite spectroradiometric measurements. The measured radiometric quantities were compared with reference values fixed in the European technical standard EN 60335-2-27 "Household and similar electrical appliances-Safety. Part 2: Particular requirements for appliances for skin exposure to ultraviolet and infrared radiation." Measurement results indicate that 88% of the examined appliances had ultraviolet emissions not compliant with the technical standard. Among the considered appliances, tanning devices equipped with low pressure lamps showed higher ultraviolet levels of effective irradiance and less compliance with standard requirements. In particular, UV emissions from 100% of low pressure appliances and from 78% of high pressure appliances exceeded the irradiance limit of 0.3 Wm set by the European technical standard.

Bilateral comparison of 1 V and 10 V standards between the DMDM (Serbia) and the BIPM, January to March 2014 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Stock, M.; Pantelic-Babic, J.; Sofranac, Z.; Zivkovic, V.

2015-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Directorate of Measures and Precious Metals (DMDM), Beograd, Serbia, was carried out from January to March 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM6 (Z6) and BIPMA (ZA), were transported by freight to DMDM. At DMDM, the reference standard for DC voltage is a Josephson Voltage Standard. The output electromotive force of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at DMDM, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by DMDM, at the level of 1.018 V and 10 V, at DMDM, UDMDM, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 13 February 2014. UDMDM - UBIPM = 0.094 µV uc = 0.072 µV, at 1 V UDMDM - UBIPM = 0.39 µV uc = 0.12 µV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at DMDM, based on KJ-90, and the uncertainty related to the comparison. The results at the 10 V level are not covered by the uncertainties with a coverage factor of 2. After the distribution of the Draft A, the DMDM discovered that the pressure gauge was defective. Some considerations on the correction to apply on the comparison result and the corresponding uncertainties are presented in the report. Nevertheless, the above results fully cover the CMCs of DMDM which are significantly larger. No corrections for temperature and pressure are applied in calibrations for customers' secondary standards. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Validation of a new algorithm for the BPM-100 electronic oscillometric office blood pressure monitor.

PubMed

Wright, J M; Mattu, G S; Perry, T L; Gelferc, M E; Strange, K D; Zorn, A; Chen, Y

2001-06-01

To test the accuracy of a new algorithm for the BPM-100, an automated oscillometric blood pressure (BP) monitor, using stored data from an independently conducted validation trial comparing the BPM-100(Beta) with a mercury sphygmomanometer. Raw pulse wave and cuff pressure data were stored electronically using embedded software in the BPM-100(Beta), during the validation trial. The 391 sets of measurements were separated objectively into two subsets. A subset of 136 measurements was used to develop a new algorithm to enhance the accuracy of the device when reading higher systolic pressures. The larger subset of 255 measurements (three readings for 85 subjects) was used as test data to validate the accuracy of the new algorithm. Differences between the new algorithm BPM-100 and the reference (mean of two observers) were determined and expressed as the mean difference +/- SD, plus the percentage of measurements within 5, 10, and 15 mmHg. The mean difference between the BPM-100 and reference systolic BP was -0.16 +/- 5.13 mmHg, with 73.7% < or = 5 mmHg, 94.9% < or = 10 mmHg and 98.8% < or = 15 mmHg. The mean difference between the BPM-100 and reference diastolic BP was -1.41 +/- 4.67 mmHg, with 78.4% < or = 5 mmHg, 92.5% < or = 10 mmHg, and 99.2% < or = 15 mmHg. These data improve upon that of the BPM-100(Beta) and pass the AAMI standard, and 'A' grade BHS protocol. This study illustrates a new method for developing and testing a change in an algorithm for an oscillometric BP monitor utilizing collected and stored electronic data and demonstrates that the new algorithm meets the AAMI standard and BHS protocol.

Shock-wave equation-of-state measurements in fused silica up to 1600 GPa

DOE PAGES

McCoy, C. A.; Gregor, M. C.; Polsin, D. N.; ...

2016-06-02

The properties of silica are important to geophysical and high-pressure equation of state research. The most prevalent crystalline form, α-quartz, has been extensively studied to TPa pressures. Recent experiments with amorphous silica, commonly referred to as fused silica, provided Hugoniot and reflectivity data up to 630 GPa using magnetically-driven aluminum impactors. This article presents measurements of the fused silica Hugoniot over the range from 200 to 1600 GPa using laser-driven shocks with a quartz standard. These results extend the measured Hugoniot of fused silica to higher pressures, but more importantly, in the 200-600 GPa range, the data are very goodmore » agreement with those obtained with a different driver and standard material. As a result, a new shock velocity-particle velocity relation is derived to fit the experimental data.« less

Pressure-Drop Considerations in the Characterization of Dew-Point Transfer Standards at High Temperatures

NASA Astrophysics Data System (ADS)

Mitter, H.; Böse, N.; Benyon, R.; Vicente, T.

2012-09-01

During calibration of precision optical dew-point hygrometers (DPHs), it is usually necessary to take into account the pressure drop induced by the gas flow between the "point of reference" and the "point of use" (mirror or measuring head of the DPH) either as a correction of the reference dew-point temperature or as part of the uncertainty estimation. At dew-point temperatures in the range of ambient temperature and below, it is sufficient to determine the pressure drop for the required gas flow, and to keep the volumetric flow constant during the measurements. In this case, it is feasible to keep the dry-gas flow into the dew-point generator constant or to measure the flow downstream the DPH at ambient temperature. In normal operation, at least one DPH in addition to the monitoring DPH are used, and this operation has to be applied to each instrument. The situation is different at high dew-point temperatures up to 95 °C, the currently achievable upper limit reported in this paper. With increasing dew-point temperatures, the reference gas contains increasing amounts of water vapour and a constant dry-gas flow will lead to a significant enhanced volume flow at the conditions at the point of use, and therefore, to a significantly varying pressure drop depending on the applied dew-point temperature. At dew-point temperatures above ambient temperature, it is also necessary to heat the reference gas and the mirror head of the DPH sufficiently to avoid condensation which will additionally increase the volume flow and the pressure drop. In this paper, a method is provided to calculate the dry-gas flow rate needed to maintain a known wet-gas flow rate through a chilled mirror for a range of temperature and pressures.

Bilateral key comparison CCM.P-K3.1 for absolute pressure measurements from 3 × 10-6 Pa to 9 × 10-4 Pa

NASA Astrophysics Data System (ADS)

Fedchak, J. A.; Bock, Th; Jousten, K.

2014-01-01

This report describes the bilateral key comparison CCM.P-K3.1 between the National Institute of Standards and Technology (NIST) and Physikalisch-Technische Bundesanstalt (PTB) for absolute pressure in the range from 3 × 10-6 Pa to 9 × 10-4 Pa. This comparison was a follow-up to the comparison CCM.P-K3. Two ionization gauges and two spinning rotor gauges (SRGs) were used as the transfer standards for the comparison. The SRGs were used to compare the standards at a pressure of 9 × 10-4 Pa and to normalize the ionization gauge readings. The two ionization gauges were used to compare the standards in the pressure range of from 3 × 10-6 Pa to 3 × 10-4 Pa. Both laboratories used dynamic expansion chambers as standards in the comparison. The two labs showed excellent agreement with each other and with the CCM.P-K3 key comparison reference value (KCRV) over the entire range. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

40 CFR 63.750 - Test methods and procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Test methods and procedures. 63.750...) National Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.750 Test methods and... engineering reference texts, or other equivalent methods. (2) The composite vapor pressure of a blended hand...

10 CFR 851.27 - Reference sources.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) American Society of Mechanical Engineers (ASME), P.O. Box 2300 Fairfield, NJ 07007. Telephone: 800-843-2763... Electrical Code,” (2005). (5) NFPA 70E, “Standard for Electrical Safety in the Workplace,” (2004). (6... Engineers (ASME) Boilers and Pressure Vessel Code, sections I through XII including applicable Code Cases...

10 CFR 851.27 - Reference sources.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) American Society of Mechanical Engineers (ASME), P.O. Box 2300 Fairfield, NJ 07007. Telephone: 800-843-2763... Electrical Code,” (2005). (5) NFPA 70E, “Standard for Electrical Safety in the Workplace,” (2004). (6... Engineers (ASME) Boilers and Pressure Vessel Code, sections I through XII including applicable Code Cases...

Nursing Education in China: Opportunities for International Collaboration.

ERIC Educational Resources Information Center

Anders, Robert L.; Harrigan, Rosanne

2002-01-01

In China, nursing has been a secondary-level trade, although modernization and pressures on the health care system are increasing the prevalence of degree programs. The ministry of health beginning to regulate practice and establish standards. Education of key administrators and stakeholders is crucial. (Contains 11 references.) (SK)

Active anterior rhinomanometry in paediatrics. Normality criteria.

PubMed

Juliá, J C; Burchés, M Enriqueta; Martorell, A

2011-01-01

Active anterior rhinomanometry with a face mask was used to establish the lower age limit for application of the technique, define normality reference standards, and determine the most appropriate pressure for referencing the nasal resistance values. A total of 409 children of both sexes and aged 5-14 years were studied. The subjects were selected from among healthy children in two primary care centres and one school. The Rhinospir 164 rhinomanometer was used for the tests. Rhinomanometry was performed according to the guidelines of the International Committee on Standardization of Rhinomanometry. The SPSS (Statistical Package for the Social Sciences) was used for the analysis of the results. The study sample was divided into five age groups involving intervals of two years from 5 to 14 years of age, and four body surface groups. The dependent variables studied (resistances and flows at pressure differences of 75 and 100) showed significantly different mean values according to age and body surface. All the mean ratios were over 1.4 units, i.e., the measures of each variable on one side and the other differed between 40% and 44%. 1.- The lower age limit for rhinomanometry is five years. 2.- The most appropriate pressures for referencing the resistance and flow values are 75 and 100. 3.- The reference standards are established with respect to total resistance and according to subject age and body surface. Copyright © 2010 SEICAP. Published by Elsevier Espana. All rights reserved.

Final report on CIPM key comparison CCM.FF-K6.2011: Comparison of the primary (national) standards of low-pressure gas flow

NASA Astrophysics Data System (ADS)

Benková, Miroslava; Makovnik, Stefan; Mickan, Bodo; Arias, Roberto; Chahine, Khaled; Funaki, Tatsuya; Li, Chunhui; Choi, Hae Man; Seredyuk, Denys; Su, Chun-Min; Windenberg, Christophe; Wright, John

2014-01-01

The comparison CCM.FF-K6.2011 was organized for the purpose of determination of the degree of equivalence of the national standards for low-pressure gas flow measurement over the range (2 to 100) m3/h. A rotary gas meter was used as a transfer standard. The measurements were provided at prescribed reference conditions. Eleven laboratories from four RMOs participated in this key comparison—EURAMET: PTB, Germany; SMU, Slovakia; LNE-LADG, France; SIM: NIST, USA; CENAM, Mexico; APMP: NMIJ AIST Japan; KRISS, Korea; NMI, Australia; NIM, China; CMS, Chinese Taipei; COOMET: GP GP Ivano-Frankivs'kstandart-metrologia, Ukraine and all participants reported independent traceability chains to the SI. All results were used in the determination of the key comparison reference value (KCRV) and the uncertainty of the KCRV. The reference value was determined at each flow separately following procedure A presented by M G Cox. The degree of equivalence with the KCRV was also calculated for each flow and laboratory. All reported results were consistent with the KCRV. This KCRV can now be used in the further regional comparisons. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Reference Manual on Interference Seals and Connectors for Undersea Electrical Applications

DTIC Science & Technology

1976-07-01

processes. It has a standard line of metal shell connectors, the ER and EB series, which are available with braided and laced harnass work and breakouts, and...Assemblies (RM) 4-10 4.3.2 Molded Plastic Assemblies (PM) 4-11 4.3.3 Metal Shell Assemblies (MS) 4-12 4.3.4 Pressure-balanced Oil-filled Assemblies...connectors according to material composition. The classes of connectors include: Rubber Molded (RM), Plastic Molded (PM), Metal Shell (MS), Pressure-Balanced

A Liquid Density Standard Over Wide Ranges of Temperature and Pressure Based on Toluene

PubMed Central

McLinden, Mark O.; Splett, Jolene D.

2008-01-01

The density of liquid toluene has been measured over the temperature range −60 °C to 200 °C with pressures up to 35 MPa. A two-sinker hydrostatic-balance densimeter utilizing a magnetic suspension coupling provided an absolute determination of the density with low uncertainties. These data are the basis of NIST Standard Reference Material® 211d for liquid density over the temperature range −50 °C to 150 °C and pressure range 0.1 MPa to 30 MPa. A thorough uncertainty analysis is presented; this includes effects resulting from the experimental density determination, possible degradation of the sample due to time and exposure to high temperatures, dissolved air, uncertainties in the empirical density model, and the sample-to-sample variations in the SRM vials. Also considered is the effect of uncertainty in the temperature and pressure measurements. This SRM is intended for the calibration of industrial densimeters. PMID:27096111

Planetary atmosphere models: A research and instructional web-based resource

NASA Astrophysics Data System (ADS)

Gray, Samuel Augustine

The effects of altitude change on the temperature, pressure, density, and speed of sound were investigated. These effects have been documented in Global Reference Atmospheric Models (GRAMs) to be used in calculating the conditions in various parts of the atmosphere for several planets. Besides GRAMs, there are several websites that provide online calculators for the 1976 US Standard Atmosphere. This thesis presents the creation of an online calculator of the atmospheres of Earth, Mars, Venus, Titan, and Neptune. The websites consist of input forms for altitude and temperature adjustment followed by a results table for the calculated data. The first phase involved creating a spreadsheet reference based on the 1976 US Standard Atmosphere and other planetary GRAMs available. Microsoft Excel was used to input the equations and make a graphical representation of the temperature, pressure, density, and speed of sound change as altitude changed using equations obtained from the GRAMs. These spreadsheets were used later as a reference for the JavaScript code in both the design and comparison of the data output of the calculators. The websites were created using HTML, CSS, and JavaScript coding languages. The calculators could accurately display the temperature, pressure, density, and speed of sound of these planets from surface values to various stages within the atmosphere. These websites provide a resource for students involved in projects and classes that require knowledge of these changes in these atmospheres. This project also created a chance for new project topics to arise for future students involved in aeronautics and astronautics.

49 CFR 195.307 - Pressure testing aboveground breakout tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... placed in service after October 2, 2000, pneumatic testing must be in accordance with section 5.3 of API Specification 12 F (incorporated by reference, see § 195.3). (b) For aboveground breakout tanks built to API Standard 620 and first placed in service after October 2, 2000, hydrostatic and pneumatic testing must be...

46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10... described in the American Society for Testing Materials Standard D 323 (incorporated by reference, see § 30... Headquarters for reading purposes or it may be purchased from the Society at 100 Barr Harbor Drive, West...

GTA Welding Research and Development for Plutonium Containment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sessions, C.E.

2002-02-21

This paper discusses the development of two welding systems that are used to contain actinide metals and oxides for long term storage. The systems are termed the bagless transfer system (BTS) and the outer container welder (OCW) system. The BTS is so named because it permits the containment of actinides without a polymeric package (i.e., bag). The development of these two systems was directed by Department of Energy Standard 3013, hereafter referred to as DOE 3013. This document defines the product and container requirements. In addition, it references national codes and standards for leak rates, ANSI N14.5, and design, Americanmore » Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section VIII (BandPVC).« less

Metrological approaches to organic chemical purity: primary reference materials for vitamin D metabolites.

PubMed

Nelson, Michael A; Bedner, Mary; Lang, Brian E; Toman, Blaza; Lippa, Katrice A

2015-11-01

Given the critical role of pure, organic compound primary reference standards used to characterize and certify chemical Certified Reference Materials (CRMs), it is essential that associated mass purity assessments be fit-for-purpose, represented by an appropriate uncertainty interval, and metrologically sound. The mass fraction purities (% g/g) of 25-hydroxyvitamin D (25(OH)D) reference standards used to produce and certify values for clinical vitamin D metabolite CRMs were investigated by multiple orthogonal quantitative measurement techniques. Quantitative (1)H-nuclear magnetic resonance spectroscopy (qNMR) was performed to establish traceability of these materials to the International System of Units (SI) and to directly assess the principal analyte species. The 25(OH)D standards contained volatile and water impurities, as well as structurally-related impurities that are difficult to observe by chromatographic methods or to distinguish from the principal 25(OH)D species by one-dimensional NMR. These impurities have the potential to introduce significant biases to purity investigations in which a limited number of measurands are quantified. Combining complementary information from multiple analytical methods, using both direct and indirect measurement techniques, enabled mitigation of these biases. Purities of 25(OH)D reference standards and associated uncertainties were determined using frequentist and Bayesian statistical models to combine data acquired via qNMR, liquid chromatography with UV absorbance and atmospheric pressure-chemical ionization mass spectrometric detection (LC-UV, LC-ACPI-MS), thermogravimetric analysis (TGA), and Karl Fischer (KF) titration.

Final report on key comparison CCAUV.A-K5: pressure calibration of laboratory standard microphones in the frequency range 2 Hz to 10 kHz

NASA Astrophysics Data System (ADS)

Avison, Janine; Barham, Richard

2014-01-01

This document and the accompanying spreadsheets constitute the final report for key comparison CCAUV.A-K5 on the pressure calibration of laboratory standard microphones in the frequency range from 2 Hz to 10 kHz. Twelve national measurement institutes took part in the key comparison and the National Physical Laboratory piloted the project. Two laboratory standard microphones IEC type LS1P were circulated to the participants and results in the form of regular calibration certificates were collected throughout the project. One of the microphones was subsequently deemed to have compromised stability for the purpose of deriving a reference value. Consequently the key comparison reference value (KCRV) has been made based on the weighted mean results for sensitivity level and for sensitivity phase from just one of the microphones. Corresponding degrees of equivalence (DoEs) have also been calculated and are presented. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Gas adsorption and desorption effects on high pressure small volume cylinders and their relevance to atmospheric trace gas analysis

NASA Astrophysics Data System (ADS)

Satar, Ece; Nyfeler, Peter; Pascale, Céline; Niederhauser, Bernhard; Leuenberger, Markus

2017-04-01

Long term atmospheric monitoring of trace gases requires great attention to precision and accuracy of the measurement setups. For globally integrated and well established greenhouse gas observation networks, the World Meteorological Organization (WMO) has set recommended compatibility goals within the framework of its Global Atmosphere Watch (GAW) Programme [1]. To achieve these challenging limits, the measurement systems are regularly calibrated with standard gases of known composition. Therefore, the stability of the primary and secondary gas standards over time is an essential issue. Past studies have explained the small instabilities in high pressure standard gas cylinders through leakage, diffusion, regulator effects, gravimetric fractionation and surface processes [2, 3]. The latter include adsorption/desorption, which are functions of temperature, pressure and surface properties. For high pressure standard gas mixtures used in atmospheric trace gas analysis, there exists only a limited amount of data and few attempts to quantify the surface processes [4, 5]. Specifically, we have designed a high pressure measurement chamber to investigate trace gases and their affinity for adsorption on different surfaces over various temperature and pressure ranges. Here, we focus on measurements of CO2, CH4 and CO using a cavity ring down spectroscopy analyzer and quantify the concentration changes due to adsorption/desorption. In this study, the first results from these prototype cylinders of steel and aluminum will be presented. References [1] World Meteorological Organization (WMO), Global Atmosphere Watch.(GAW): Report No. 229, 18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Tracers Measurement Techniques (GGMT-2015), 2016. [2] Keeling, R. F., Manning, A. C., Paplawsky, W. J., and Cox, A. C.: On the long-term stability of reference gases for atmospheric O2 /N2 and CO2 measurements, Tellus B, 59, 10.3402/tellusb.v59i1.16964, 2007. [3] Langenfelds, R. L., van der Schoot, M. V., Francey, R. J., Steele, L. P., Schmidt, M., and Mukai, H.: Modification of air standard composition by diffusive and surface processes, Journal of Geophysical Research: Atmospheres, 110, n/a-n/a, 10.1029/2004JD005482, 2005. [4] Leuenberger, M. C., Schibig, M. F., and Nyfeler, P.: Gas adsorption and desorption effects on cylinders and their importance for long-term gas records, Atmos. Meas. Tech., 8, 5289-5299, 10.5194/amt-8-5289-2015, 2015 [5] Miller, W. R., Rhoderick, G. C., and Guenther, F. R.: Investigating Adsorption/Desorption of Carbon Dioxide in Aluminum Compressed Gas Cylinders, Analytical Chemistry, 87, 1957-1962, 10.1021/ac504351b, 2015.

A System And Method To Determine Thermophysical Properties Of A Multi-Component Gas At Arbitrary Temperature And Pressure

DOEpatents

Morrow, Thomas E.; Behring, II, Kendricks A.

2004-03-09

A method to determine thermodynamic properties of a natural gas hydrocarbon, when the speed of sound in the gas is known at an arbitrary temperature and pressure. Thus, the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for mass flow calculations, to determine the speed of sound at standard pressure and temperature, and to determine various thermophysical characteristics of the gas.

Device For Determining Therophysical Properties Of A Multi-Component Gas At Arbitrary Temperature And Pressure

DOEpatents

Morrow, Thomas B.; Behring, II, Kendricks A.

2005-02-01

A computer product for determining thermodynamic properties of a natural gas hydrocarbon, when the speed of sound in the gas is known at an arbitrary temperature and pressure. Thus, the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for mass flow calculations, to determine the speed of sound at standard pressure and temperature, and to determine various thermophysical characteristics of the gas.

Reference values of brachial-ankle pulse wave velocity according to age and blood pressure in a central Asia population.

PubMed

Yiming, Gulinuer; Zhou, Xianhui; Lv, Wenkui; Peng, Yi; Zhang, Wenhui; Cheng, Xinchun; Li, Yaodong; Xing, Qiang; Zhang, Jianghua; Zhou, Qina; Zhang, Ling; Lu, Yanmei; Wang, Hongli; Tang, Baopeng

2017-01-01

Brachial-ankle pulse wave velocity (baPWV), a direct measure of aortic stiffness, has increasingly become an important assessment for cardiovascular risk. The present study established the reference and normal values of baPWV in a Central Asia population in Xinjiang, China. We recruited participants from a central Asia population in Xinjiang, China. We performed multiple regression analysis to investigate the determinants of baPWV. The median and 10th-90th percentiles were calculated to establish the reference and normal values based on these categories. In total, 5,757 Han participants aged 15-88 years were included in the present study. Spearman correlation analysis showed that age (r = 0.587, p < 0.001) and mean blood pressure (MBP, r = 0.599, p <0.001) were the major factors influencing the values of baPWV in the reference population. Furthermore, in the multiple linear regression analysis, the standardized regression coefficients of age (0.445) and MBP (0.460) were much higher than those of body mass index, triglyceride, and glycemia (-0.054, 0.035, and 0.033, respectively). In the covariance analysis, after adjustment for age and MBP, only diabetes was the significant independent determinant of baPWV (p = 0.009). Thus, participants with diabetes were excluded from the reference value population. The reference values ranged from 14.3 to 25.2 m/s, and the normal values ranged from 13.9 to 21.2 m/s. This is the first study that has established the reference and normal values for baPWV according to age and blood pressure in a Central Asia population.

A survey of blood pressure in Lebanese children and adolescence

PubMed Central

Merhi, Bassem Abou; Al-Hajj, Fatima; Al-Tannir, Mohamad; Ziade, Fouad; El-Rajab, Mariam

2011-01-01

Background: Blood pressure varies between populations due to ethnic and environmental factors. Therefore, normal blood pressure values should be determined for different populations. Aims: The aim of this survey was to produce blood pressure nomograms for Lebanese children in order to establish distribution curves of blood pressure by age and sex. Subjects and Methods: We conducted a survey of blood pressure in 5710 Lebanese schoolchildren aged 5 to 15 years (2918 boys and 2792 girls), and studied the distribution of systolic and diastolic blood pressure in these children and adolescents. Blood pressure was measured with a mercury sphygmomanometer using a standardized technique. Results: Both systolic and diastolic blood pressure had a positive correlation with weight, height, age, and body mass index (r= 0.648, 0.643, 0.582, and 0.44, respectively) (P < .001). There was no significant difference in the systolic and diastolic blood pressure in boys compared to girls of corresponding ages. However, the average annual increase in systolic blood pressure was 2.86 mm Hg in boys and 2.63 mm Hg in girls, whereas the annual increase in diastolic blood pressure was 1.72 mm Hg in boys and 1.48 mm Hg in girls. The prevalence of high and high-normal blood pressure at the upper limit of normal (between the 90th and 95th percentile, at risk of future hypertension if not managed adequately), was 10.5% in boys and 6.9% in girls, with similar distributions among the two sexes. Conclusions: We present the first age-specific reference values for blood pressure of Lebanese children aged 5 to 15 years based on a good representative sample. The use of these reference values should help pediatricians identify children with normal, high-normal and high blood pressure. PMID:22540059

A survey of blood pressure in Lebanese children and adolescence.

PubMed

Merhi, Bassem Abou; Al-Hajj, Fatima; Al-Tannir, Mohamad; Ziade, Fouad; El-Rajab, Mariam

2011-01-01

Blood pressure varies between populations due to ethnic and environmental factors. Therefore, normal blood pressure values should be determined for different populations. The aim of this survey was to produce blood pressure nomograms for Lebanese children in order to establish distribution curves of blood pressure by age and sex. We conducted a survey of blood pressure in 5710 Lebanese schoolchildren aged 5 to 15 years (2918 boys and 2792 girls), and studied the distribution of systolic and diastolic blood pressure in these children and adolescents. Blood pressure was measured with a mercury sphygmomanometer using a standardized technique. Both systolic and diastolic blood pressure had a positive correlation with weight, height, age, and body mass index (r= 0.648, 0.643, 0.582, and 0.44, respectively) (P < .001). There was no significant difference in the systolic and diastolic blood pressure in boys compared to girls of corresponding ages. However, the average annual increase in systolic blood pressure was 2.86 mm Hg in boys and 2.63 mm Hg in girls, whereas the annual increase in diastolic blood pressure was 1.72 mm Hg in boys and 1.48 mm Hg in girls. The prevalence of high and high-normal blood pressure at the upper limit of normal (between the 90(th) and 95(th) percentile, at risk of future hypertension if not managed adequately), was 10.5% in boys and 6.9% in girls, with similar distributions among the two sexes. We present the first age-specific reference values for blood pressure of Lebanese children aged 5 to 15 years based on a good representative sample. The use of these reference values should help pediatricians identify children with normal, high-normal and high blood pressure.

Earth Global Reference Atmospheric Model (GRAM) Overview and Updates: DOLWG Meeting

NASA Technical Reports Server (NTRS)

White, Patrick

2017-01-01

What is Earth-GRAM (Global Reference Atmospheric Model): Provides monthly mean and standard deviation for any point in atmosphere - Monthly, Geographic, and Altitude Variation; Earth-GRAM is a C++ software package - Currently distributed as Earth-GRAM 2016; Atmospheric variables included: pressure, density, temperature, horizontal and vertical winds, speed of sound, and atmospheric constituents; Used by engineering community because of ability to create dispersions in atmosphere at a rapid runtime - Often embedded in trajectory simulation software; Not a forecast model; Does not readily capture localized atmospheric effects.

Should care homes adopt a static-led approach to pressure ulcer prevention?

PubMed

Keen, Delia Catherine

A static-led approach refers to the provision of high-specification foam mattresses for the whole of a population at risk of pressure damage. Such mattresses have been found to reduce the risk of pressure ulceration and cost less overall than standard mattresses, even in populations where only 1 in 100 patients develops a pressure ulcer. Reduced pressure ulcer prevalence and reduced costs resulting from decreased expenditure on dynamic mattresses following the implementation of a static-led approach have been reported. Pressure ulcers cause pain, a reduced quality of life, loss of independence, depression and social isolation for those in whom they develop. Organizations are increasingly having to pay out large sums of money following litigation surrounding pressure ulcers. This article explains why NHS healthcare providers and private care organizations need to work together to consider implementing a static-led approach to pressure ulcer prevention within care homes in order to reduce pressure ulcer incidence cost-effectively within their local populations.

46 CFR 54.01-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) ASTM International (formerly American Society for Testing and Materials) (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959: (1) ASTM A 20/A 20M-97a, Standard Specification for General Requirements for Steel Plates for Pressure Vessels (“ASTM A 20”), 54.05-10; 54.25-10; (2) ASTM A 203/A 203M-97...

Pressure ulcer risk assessment and prevention: a systematic comparative effectiveness review.

PubMed

Chou, Roger; Dana, Tracy; Bougatsos, Christina; Blazina, Ian; Starmer, Amy J; Reitel, Katie; Buckley, David I

2013-07-02

Pressure ulcers are associated with substantial health burdens but may be preventable. To review the clinical utility of pressure ulcer risk assessment instruments and the comparative effectiveness of preventive interventions in persons at higher risk. MEDLINE (1946 through November 2012), CINAHL, the Cochrane Library, grant databases, clinical trial registries, and reference lists. Randomized trials and observational studies on effects of using risk assessment on clinical outcomes and randomized trials of preventive interventions on clinical outcomes. Multiple investigators abstracted and checked study details and quality using predefined criteria. One good-quality trial found no evidence that use of a pressure ulcer risk assessment instrument, with or without a protocolized intervention strategy based on assessed risk, reduces risk for incident pressure ulcers compared with less standardized risk assessment based on nurses' clinical judgment. In higher-risk populations, 1 good-quality and 4 fair-quality randomized trials found that more advanced static support surfaces were associated with lower risk for pressure ulcers compared with standard mattresses (relative risk range, 0.20 to 0.60). Evidence on the effectiveness of low-air-loss and alternating-air mattresses was limited, with some trials showing no clear differences from advanced static support surfaces. Evidence on the effectiveness of nutritional supplementation, repositioning, and skin care interventions versus usual care was limited and had methodological shortcomings, precluding strong conclusions. Only English-language articles were included, publication bias could not be formally assessed, and most studies had methodological shortcomings. More advanced static support surfaces are more effective than standard mattresses for preventing ulcers in higher-risk populations. The effectiveness of formal risk assessment instruments and associated intervention protocols compared with less standardized assessment methods and the effectiveness of other preventive interventions compared with usual care have not been clearly established.

A Non-Invasive Assessment of Cardiopulmonary Hemodynamics with MRI in Pulmonary Hypertension

PubMed Central

Bane, Octavia; Shah, Sanjiv J.; Cuttica, Michael J.; Collins, Jeremy D.; Selvaraj, Senthil; Chatterjee, Neil R.; Guetter, Christoph; Carr, James C.; Carroll, Timothy J.

2015-01-01

Purpose We propose a method for non-invasive quantification of hemodynamic changes in the pulmonary arteries resulting from pulmonary hypertension (PH). Methods Using a two-element windkessel model, and input parameters derived from standard MRI evaluation of flow, cardiac function and valvular motion, we derive: pulmonary artery compliance (C), mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), pulmonary capillary wedge pressure (PCWP), time-averaged intra-pulmonary pressure waveforms and pulmonary artery pressures (systolic (sPAP) and diastolic (dPAP)). MRI results were compared directly to reference standard values from right heart catheterization (RHC) obtained in a series of patients with suspected pulmonary hypertension (PH). Results In 7 patients with suspected PH undergoing RHC, MRI and echocardiography, there was no statistically significant difference (p<0.05) between parameters measured by MRI and RHC. Using standard clinical cutoffs to define PH (mPAP ≥ 25 mmHg), MRI was able to correctly identify all patients as having pulmonary hypertension, and to correctly distinguish between pulmonary arterial (mPAP≥ 25 mmHg, PCWP<15 mmHg) and venous hypertension (mPAP ≥ 25 mmHg, PCWP ≥ 15 mmHg) in 5 of 7 cases. Conclusions We have developed a mathematical model capable of quantifying physiological parameters that reflect the severity of PH. PMID:26283577

Dynamic pressure sensitivity determination with Mach number method

NASA Astrophysics Data System (ADS)

Sarraf, Christophe; Damion, Jean-Pierre

2018-05-01

Measurements of pressure in fast transient conditions are often performed even if the dynamic characteristic of the transducer are not traceable to international standards. Moreover, the question of a primary standard in dynamic pressure is still open, especially for gaseous applications. The question is to improve dynamic standards in order to respond to expressed industrial needs. In this paper, the method proposed in the EMRP IND09 ‘Dynamic’ project, which can be called the ‘ideal shock tube method’, is compared with the ‘collective standard method’ currently used in the Laboratoire de Métrologie Dynamique (LNE/ENSAM). The input is a step of pressure generated by a shock tube. The transducer is a piezoelectric pressure sensor. With the ‘ideal shock tube method’ the sensitivity of a pressure sensor is first determined dynamically. This method requires a shock tube implemented with piezoelectric shock wave detectors. The measurement of the Mach number in the tube allows an evaluation of the incident pressure amplitude of a step using a theoretical 1D model of the shock tube. Heat transfer, other actual effects and effects of the shock tube imperfections are not taken into account. The amplitude of the pressure step is then used to determine the sensitivity in dynamic conditions. The second method uses a frequency bandwidth comparison to determine pressure at frequencies from quasi-static conditions, traceable to static pressure standards, to higher frequencies (up to 10 kHz). The measurand is also a step of pressure generated by a supposed ideal shock tube or a fast-opening device. The results are provided as a transfer function with an uncertainty budget assigned to a frequency range, also deliverable frequency by frequency. The largest uncertainty in the bandwidth of comparison is used to trace the final pressure step level measured in dynamic conditions, owing that this pressure is not measurable in a steady state on a shock tube. A reference sensor thereby calibrated can be used in a comparison measurement process. At high frequencies the most important component of the uncertainty in this method is due to actual shock tube complex effects not already functionalized nowadays or thought not to be functionalized in this kind of direct method. After a brief review of both methods and a brief review of the determination of the transfer function of pressure transducers, and the budget of associated uncertainty for the dynamic calibration of a pressure transducer in gas, this paper presents a comparison of the results obtained with the ‘ideal shock tube’ and the ‘collective standard’ methods.

EURAMET.M.P-S9: comparison in the negative gauge pressure range -950 to 0 hPa

NASA Astrophysics Data System (ADS)

Saxholm, S.; Otal, P.; AltintaS, A.; Bermanec, L. G.; Durgut, Y.; Hanrahan, R.; Kocas, I.; Lefkopoulos, A.; Pražák, D.; Sandu, I.; Åetina, J.; Spohr, I.; Steindl, D.; Tammik, K.; Testa, N.

2016-01-01

A comparison in the negative gauge pressure range was arranged in the period 2011 - 2012. A total of 14 laboratories participated in this comparison: BEV (Austria), CMI (Czech Republic), DANIAmet-FORCE (Denmark), EIM (Greece), HMI/FSB-LPM (Croatia), INM (Romania), IPQ (Portugal), LNE (France), MCCAA (Malta), METROSERT (Estonia), MIKES (Finland), MIRS/IMT/LMT (Slovenia), NSAI (Ireland) and UME (Turkey). The project was divided into two loops: Loop1, piloted by MIKES, and Loop2, piloted by LNE. The results of the two loops are reported separately: Loop1 results are presented in this paper. The transfer standard was Beamex MC5 no. 25516865 with internal pressure module INT1C, resolution 0.01 hPa. The nominal pressure range of the INT1C is -1000 hPa to +1000 hPa. The nominal pressure points for the comparison were 0 hPa, -200 hPa, -400 hPa, -600 hPa, -800 hPa and -950 hPa. The reference values and their uncertainties as well as the difference uncertainty between the laboratory results and the reference values were determined from the measurement data by Monte Carlo simulations. Stability uncertainty of the transfer standard was included in the final difference uncertainty. Degrees of equivalences and mutual equivalences between the laboratories were calculated. Each laboratory reported results for all twelve measurement points, which means that there were 168 reported values in total. Some 163 of the 168 values (97 %) agree with the reference values within the expanded uncertainties, with a coverage factor k = 2. Among the laboratories, four different methods were used to determine negative gauge pressure. It is concluded that special attention must be paid to the measurements and methods when measuring negative gauge pressures. There might be a need for a technical guide or a workshop that provides information about details and practices related to the measurements of negative gauge pressure, as well as differences between the different methods. The comparison is registered as EURAMET project no. 1170 and as a supplementary comparison EURAMET.M.P-S9 in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Measurement of blood pressure for the diagnosis and management of hypertension in different ethnic groups: one size fits all.

PubMed

Gill, Paramjit; Haque, M Sayeed; Martin, Una; Mant, Jonathan; Mohammed, Mohammed A; Heer, Gurdip; Johal, Amanpreet; Kaur, Ramandeep; Schwartz, Claire; Wood, Sally; Greenfield, Sheila M; McManus, Richard J

2017-02-08

Hypertension is a major risk factor for cardiovascular disease and prevalence varies by ethnic group. The diagnosis and management of blood pressure are informed by guidelines largely based on data from white populations. This study addressed whether accuracy of blood pressure measurement in terms of diagnosis of hypertension varies by ethnicity by comparing two measurement modalities (clinic blood pressure and home monitoring) with a reference standard of ambulatory BP monitoring in three ethnic groups. Cross-sectional population study (June 2010 - December 2012) with patients (40-75 years) of white British, South Asian and African Caribbean background with and without a previous diagnosis of hypertension recruited from 28 primary care practices. The study compared the test performance of clinic BP (using various protocols) and home-monitoring (1 week) with a reference standard of mean daytime ambulatory measurements using a threshold of 140/90 mmHg for clinic and 135/85 mmHg for out of office measurement. A total of 551 participants had complete data of whom 246 were white British, 147 South Asian and 158 African Caribbean. No consistent difference in accuracy of methods of blood pressure measurement was observed between ethnic groups with or without a prior diagnosis of hypertension: for people without hypertension, clinic measurement using three different methodologies had high specificity (75-97%) but variable sensitivity (33-65%) whereas home monitoring had sensitivity of 68-88% and specificity of 64-80%. For people with hypertension, detection of a raised blood pressure using clinic measurements had sensitivities of 34-69% with specificity of 73-92% and home monitoring had sensitivity (81-88%) and specificity (55-65%). For people without hypertension, ABPM remains the choice for diagnosing hypertension compared to the other modes of BP measurement regardless of ethnicity. Differences in accuracy of home monitoring and clinic monitoring (higher sensitivity of the former; higher specificity of the latter) were also not affected by ethnicity.

Individual and Joint Expert Judgments as Reference Standards in Artifact Detection

PubMed Central

Verduijn, Marion; Peek, Niels; de Keizer, Nicolette F.; van Lieshout, Erik-Jan; de Pont, Anne-Cornelie J.M.; Schultz, Marcus J.; de Jonge, Evert; de Mol, Bas A.J.M.

2008-01-01

Objective To investigate the agreement among clinical experts in their judgments of monitoring data with respect to artifacts, and to examine the effect of reference standards that consist of individual and joint expert judgments on the performance of artifact filters. Design Individual judgments of four physicians, a majority vote judgment, and a consensus judgment were obtained for 30 time series of three monitoring variables: mean arterial blood pressure (ABPm), central venous pressure (CVP), and heart rate (HR). The individual and joint judgments were used to tune three existing automated filtering methods and to evaluate the performance of the resulting filters. Measurements The interrater agreement was calculated in terms of positive specific agreement (PSA). The performance of the artifact filters was quantified in terms of sensitivity and positive predictive value (PPV). Results PSA values between 0.33 and 0.85 were observed among clinical experts in their selection of artifacts, with relatively high values for CVP data. Artifact filters developed using judgments of individual experts were found to moderately generalize to new time series and other experts; sensitivity values ranged from 0.40 to 0.60 for ABPm and HR filters (PPV: 0.57–0.84), and from 0.63 to 0.80 for CVP filters (PPV: 0.71–0.86). A higher performance value for the filters was found for the three variable types when joint judgments were used for tuning the filtering methods. Conclusion Given the disagreement among experts in their individual judgment of monitoring data with respect to artifacts, the use of joint reference standards obtained from multiple experts is recommended for development of automatic artifact filters. PMID:18096912

The Chemical Shift Baseline for High-Pressure NMR Spectra of Proteins.

PubMed

Frach, Roland; Kibies, Patrick; Böttcher, Saraphina; Pongratz, Tim; Strohfeldt, Steven; Kurrmann, Simon; Koehler, Joerg; Hofmann, Martin; Kremer, Werner; Kalbitzer, Hans Robert; Reiser, Oliver; Horinek, Dominik; Kast, Stefan M

2016-07-18

High-pressure (HP) NMR spectroscopy is an important method for detecting rare functional states of proteins by analyzing the pressure response of chemical shifts. However, for the analysis of the shifts it is mandatory to understand the origin of the observed pressure dependence. Here we present experimental HP NMR data on the (15) N-enriched peptide bond model, N-methylacetamide (NMA), in water, combined with quantum-chemical computations of the magnetic parameters using a pressure-sensitive solvation model. Theoretical analysis of NMA and the experimentally used internal reference standard 4,4-dimethyl-4-silapentane-1-sulfonic (DSS) reveal that a substantial part of observed shifts can be attributed to purely solvent-induced electronic polarization of the backbone. DSS is only marginally responsive to pressure changes and is therefore a reliable sensor for variations in the local magnetic field caused by pressure-induced changes of the magnetic susceptibility of the solvent. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Validation of the blood pressure measurement device Erkameter 125 PRO according to the European Society of Hypertension International Protocol revision 2010.

PubMed

Beime, Beate; Deutsch, Cornelia; Krüger, Ralf; Zimmermann, Erik; Bramlage, Peter

2016-12-01

The aim of the present study was to validate the blood pressure (BP) measurement device Erkameter 125 PRO according to the International Protocol revision 2010 of the European Society of Hypertension (ESH-IP2). In 33 patients aged 32-79 years, BP measurements were performed alternately using the Erkameter 125 PRO and the reference mercury sphygmomanometer according to ESH-IP revision 2010. For the analysis, a total of 99 comparisons were included. All absolute differences between the test device and the reference were within 10 mmHg for systolic blood pressure (SBP), and all except one for diastolic blood pressure (DBP). A total of 93 out of 99 comparisons for SBP showed an absolute difference within 5 mmHg and 92 out of 99 for DBP. The mean±SD difference between the Erkameter 125 PRO and the standard reference was -0.5±3.5 mmHg for SBP and 0.5±3.5 mmHg for DBP. As to part 2 of ESH-IP 2010, all patients had a minimum of two out of three measurements within 5 mmHg difference for SBP and 31 out of 33 patients for DBP. The Erkameter 125 PRO fulfilled the requirements of parts 1 and 2 of the ESH-IP revision 2010 and can be recommended for office BP measurements in adults.

Cryogenic flow rate measurement with a laser Doppler velocimetry standard

NASA Astrophysics Data System (ADS)

Maury, R.; Strzelecki, A.; Auclercq, C.; Lehot, Y.; Loubat, S.; Chevalier, J.; Ben Rayana, F.

2018-03-01

A very promising alternative to the state-of-the-art static volume measurements for liquefied natural gas (LNG) custody transfer processes is the dynamic principle of flow metering. As the Designated Institute (DI) of the LNE (‘Laboratoire National de métrologie et d’Essais’, being the French National Metrology Institute) for high-pressure gas flow metering, Cesame-Exadebit is involved in various research and development programs. Within the framework of the first (2010-2013) and second (2014-2017) EURAMET Joint Research Project (JRP), named ‘Metrological support for LNG custody transfer and transport fuel applications’, Cesame-Exadebit explored a novel cryogenic flow metering technology using laser Doppler velocimetry (LDV) as an alternative to ultrasonic and Coriolis flow metering. Cesame-Exadebit is trying to develop this technique as a primary standard for cryogenic flow meters. Currently, cryogenic flow meters are calibrated at ambient temperatures with water. Results are then extrapolated to be in the Reynolds number range of real applications. The LDV standard offers a unique capability to perform online calibration of cryogenic flow meters in real conditions (temperature, pressure, piping and real flow disturbances). The primary reference has been tested on an industrial process in a LNG terminal during truck refuelling. The reference can calibrate Coriolis flow meters being used daily with all the real environmental constraints, and its utilisation is transparent for LNG terminal operators. The standard is traceable to Standard International units and the combined extended uncertainties have been determined and estimated to be lower than 0.6% (an ongoing improvement to reducing the correlation function uncertainty, which has a major impact in the uncertainty estimation).

Burst strength of tubing and casing based on twin shear unified strength theory.

PubMed

Lin, Yuanhua; Deng, Kuanhai; Sun, Yongxing; Zeng, Dezhi; Liu, Wanying; Kong, Xiangwei; Singh, Ambrish

2014-01-01

The internal pressure strength of tubing and casing often cannot satisfy the design requirements in high pressure, high temperature and high H2S gas wells. Also, the practical safety coefficient of some wells is lower than the design standard according to the current API 5C3 standard, which brings some perplexity to the design. The ISO 10400: 2007 provides the model which can calculate the burst strength of tubing and casing better than API 5C3 standard, but the calculation accuracy is not desirable because about 50 percent predictive values are remarkably higher than real burst values. So, for the sake of improving strength design of tubing and casing, this paper deduces the plastic limit pressure of tubing and casing under internal pressure by applying the twin shear unified strength theory. According to the research of the influence rule of yield-to-tensile strength ratio and mechanical properties on the burst strength of tubing and casing, the more precise calculation model of tubing-casing's burst strength has been established with material hardening and intermediate principal stress. Numerical and experimental comparisons show that the new burst strength model is much closer to the real burst values than that of other models. The research results provide an important reference to optimize the tubing and casing design of deep and ultra-deep wells.

Burst Strength of Tubing and Casing Based on Twin Shear Unified Strength Theory

PubMed Central

Lin, Yuanhua; Deng, Kuanhai; Sun, Yongxing; Zeng, Dezhi; Liu, Wanying; Kong, Xiangwei; Singh, Ambrish

2014-01-01

The internal pressure strength of tubing and casing often cannot satisfy the design requirements in high pressure, high temperature and high H2S gas wells. Also, the practical safety coefficient of some wells is lower than the design standard according to the current API 5C3 standard, which brings some perplexity to the design. The ISO 10400: 2007 provides the model which can calculate the burst strength of tubing and casing better than API 5C3 standard, but the calculation accuracy is not desirable because about 50 percent predictive values are remarkably higher than real burst values. So, for the sake of improving strength design of tubing and casing, this paper deduces the plastic limit pressure of tubing and casing under internal pressure by applying the twin shear unified strength theory. According to the research of the influence rule of yield-to-tensile strength ratio and mechanical properties on the burst strength of tubing and casing, the more precise calculation model of tubing-casing's burst strength has been established with material hardening and intermediate principal stress. Numerical and experimental comparisons show that the new burst strength model is much closer to the real burst values than that of other models. The research results provide an important reference to optimize the tubing and casing design of deep and ultra-deep wells. PMID:25397886

KEY COMPARISON Bilateral comparison of 1.018 V and 10 V standards between the NSAI-NML (Ireland) and the BIPM, March to April 2010 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Power, O.; Solve, S.; Chayramy, R.; Stock, M.

2010-01-01

As a part of the ongoing BIPM key comparisons BIPM.EM-K11.a and b, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and of the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out from March to April 2010. Two BIPM Zener diode-based travelling standards were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage is maintained at the 10 V level by means of a group of characterized Zener diode-based electronic voltage standards. The output EMF of each travelling standard, at the 10 V output terminals, was measured by direct comparison with the group standard. Measurements of the output EMF of the travelling standards at the 1.018 V output terminals were made using a potentiometer, standardized against the local 10 V reference standard. At the BIPM, the travelling standards were calibrated at both voltages before and after the measurements at NSAI-NML, using the BIPM Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages on internal temperature and ambient pressure. The comparison results show that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated expanded uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Tables of thermodynamic properties of helium magnet coolant, revision A

NASA Astrophysics Data System (ADS)

McAshan, M.

1992-07-01

The most complete treatment of the thermodynamic properties of helium at the present time is the monograph by McCarty: 'Thermodynamic Properties of Helium 4 from 2 to 1500 K at Pressures to 10(exp 8) Pa', Robert D. McCarty, Journal of Physical and Chemical Reference Data, Vol. 2, page 923-1040 (1973). In this work the complete range of data on helium is examined and the P-V-T surface is described by an equation of state consisting of three functions P(r,T) covering different regions together with rules for making the transition from one region to another. From this thermodynamic compilation together with correlations of the transport properties of helium was published the well-known NBS Technical Note: 'Thermophysical Properties of Helium 4 from 2 to 1500 K with pressures to 1000 Atmospheres', Robert D. McCarty, US Department of Commerce, National Bureau of Standards Technical Note 631 (1972). This is the standard reference for helium cryogenics. The NBS 631 tables cover a wide range of temperature and pressure, and as a consequence, the number of points tabulated in the region of the single phase coolant for the SSC magnets are relatively few. The present work sets out to cover the range of interest in more detail in a way that is consistent with NBS 631. This new table is essentially identical to the older one and can be used as an auxiliary to it.

An echocardiographic study of healthy Border Collies with normal reference ranges for the breed.

PubMed

Jacobson, Jake H; Boon, June A; Bright, Janice M

2013-06-01

The objectives of this study were to obtain standard echocardiographic measurements from healthy Border Collies and to compare these measurements to those previously reported for a general population of dogs. Standard echocardiographic data were obtained from twenty apparently healthy Border Collie dogs. These data (n = 20) were compared to data obtained from a general population of healthy dogs (n = 69). Border Collies were deemed healthy based on normal history, physical examination, complete blood count, serum biochemical profile, electrocardiogram, and blood pressure, with no evidence of congenital or acquired heart disease on echocardiographic examination. Standard two dimensional, M-mode, and Doppler echocardiographic measurements were obtained and normal ranges determined. The data were compared to data previously obtained at our hospital from a general population of normal dogs. Two dimensional, M-mode, and Doppler reference ranges for healthy Border Collies are presented in tabular form. Comparison of the weight adjusted M-mode echocardiographic means from Border Collies to those from the general population of dogs showed Border Collies to have larger left ventricular systolic and diastolic dimensions, smaller interventricular septal thickness, and lower fractional shortening. There are differences in some echocardiographic parameters between healthy Border Collies and the general dog population, and the echocardiographic reference ranges provided in this study should be used as breed specific reference values for Border Collies. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of abdominal negative-pressure wound therapy on the measurement of intra-abdominal pressure.

PubMed

García, Alberto Federico; Sánchez, Álvaro Ignacio; Gutiérrez, Álvaro José; Bayona, Juan Gabriel; Naranjo, María Paula; Lago, Sebastián; Puyana, Juan Carlos

2018-07-01

In critically ill surgical patients undergoing abdominal negative-pressure wound therapy (NPWT), it remains uncertain whether or not intra-abdominal pressure (IAP) measurements should be obtained when NPWT is activated. We aimed to determine agreement between IAP measured with and without NPWT. In this analytic cross-sectional study, critically ill surgical adults (≥18 y) requiring abdominal NPWT for temporary abdominal closure after a damage control laparotomy were selected. Patients with urinary tract injuries or with pelvic packing were excluded. Paired IAP measures were performed in the same patient, with and without NPWT; two different operators performed the measures unaware of the other's result. Bland-Altman methods assessed the agreement between the two measures. Subgroup analyses (trauma and nontrauma) were performed. There were 198 IAP measures (99 pairs) in 38 patients. Mean IAP with and without NPWT were 8.33 (standard deviation 4.01) and 8.65 (standard deviation 4.04), respectively. Mean IAP difference was -0.323 (95% confidence interval -0.748 to 0.101), and reference range for difference was -4.579 to 3.932 (P = 0.864). From 112 IAP measures (56 pairs) in 21 trauma patients, mean IAP difference was -0.268 (95% confidence interval -0.867 to 0.331), and reference range for the difference was -4.740 to 4.204 (P = 0.427). There was no statistically significant disagreement in IAP measures. IAP could be measured with or without NPWT. In critically ill surgical patients with abdominal NPWT for temporary abdominal closure, monitoring and management of IAP either with or without NPWT is recommended. Copyright © 2018 Elsevier Inc. All rights reserved.

Thermogravimetric study of vapor pressure of TATP synthesized without recrystallization.

PubMed

Mbah, Jonathan; Knott, Debra; Steward, Scott

2014-11-01

This study aims at characterizing the vapor pressure signatures generated by triacetone triperoxide (TATP) that was synthesized without recrystallization by thermogravimmetric analysis (TGA) for exploitation by standoff detection technologies of explosive devices. The thermal behavior of the nonrecrystallized sample was compared with reported values. Any phase change, melting point and decomposition identification were studied by differential scanning calorimeter. Vapor pressures were estimated by the Langmuir method of evaporation from an open surface in a vacuum. Vapor pressures of TATP at different temperatures were calculated using the linear logarithmic relationship obtained from benzoic acid reference standard. Sublimation of TATP was found to follow apparent zero-order kinetics and sublimes at steady rates at 298 K and above. While the enthalpy of sublimation found, 71.7 kJ mol(-1), is in agreement with reported values the vapor pressures deviated significantly. The differences in the vapor pressures behavior are attributable to the synthesis pathway chosen in this study. Copyright © 2014 Elsevier B.V. All rights reserved.

Performance of a Blood Pressure Smartphone App in Pregnant Women: The iPARR Trial (iPhone App Compared With Standard RR Measurement).

PubMed

Raichle, Christina J; Eckstein, Jens; Lapaire, Olav; Leonardi, Licia; Brasier, Noé; Vischer, Annina S; Burkard, Thilo

2018-06-01

Hypertensive disorders are one of the leading causes of maternal death worldwide. Several smartphone apps claim to measure blood pressure (BP) using photoplethysmographic signals recorded by smartphone cameras. However, no single app has been validated for this use to date. We aimed to validate a new, promising smartphone algorithm. In this subgroup analysis of the iPARR trial (iPhone App Compared With Standard RR Measurement), we tested the Preventicus BP smartphone algorithm on 32 pregnant women. The trial was conducted based on the European Society of Hypertension International Protocol revision 2010 for validation of BP measuring devices in adults. Each individual received 7 sequential BP measurements starting with the reference device (Omron-HBP-1300) and followed by the smartphone measurement, resulting in 96 BP comparisons. Validation requirements of the European Society of Hypertension International Protocol revision 2010 were not fulfilled. Mean (±SD) systolic BP disagreement between the test and reference devices was 5.0 (±14.5) mm Hg. The number of absolute differences between test and reference device within 5, 10, and 15 mm Hg was 31, 53, and 64 of 96, respectively. A Bland-Altman plot showed an overestimation of smartphone-determined systolic BP in comparison with reference systolic BP in low range but an underestimation in medium-range BP. The Preventicus BP smartphone algorithm failed the accuracy criteria for estimating BP in pregnant women and was thus not commercialized. Pregnant women should be discouraged from using BP smartphone apps, unless there are algorithms specifically validated according to common protocols. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02552030. © 2018 American Heart Association, Inc.

Pressure Relief Devices

NASA Astrophysics Data System (ADS)

Manha, William D.

2010-09-01

Pressure relief devices are used in pressure systems and on pressure vessels to prevent catastrophic rupture or explosion from excessive pressure. Pressure systems and pressure vessels have manufacturers maximum rated operating pressures or maximum design pressures(MDP) for which there are relatively high safety factors and minimum risk of rupture or explosion. Pressure systems and pressure vessels that have a potential to exceed the MDP by being connected to another higher pressure source, a compressor, or heat to water(boiler) are required to have over-pressure protecting devices. Such devices can be relief valves and/or burst discs to safely relieve potentially excessive pressure and prevent unacceptable ruptures and explosions which result in fail-safe pressure systems and pressure vessels. Common aerospace relief valve and burst disc requirements and standards will be presented. This will include the NASA PSRP Interpretation Letter TA-88-074 Fault Tolerance of Systems Using Specially Certified Burst Disks that dictates burst disc requirements for payloads on Shuttle. Two recent undesirable manned space payloads pressure relief devices and practices will be discussed, as well as why these practices should not be continued. One example for discussion is the use of three burst discs that have been placed in series to comply with safety requirements of three controls to prevent a catastrophic hazard of the over-pressurization and rupture of pressure system and/or vessels. The cavities between the burst discs are evacuated and are the reference pressures for activating the two upstream burst discs. If the upstream burst disc leaks into the reference cavity, the reference pressure increases and it can increase the burst disc activating pressure and potentially result in the burst disc assembly being ineffective for over pressure protection. The three burst discs-in-series assembly was found acceptable because the burst discs are designed for minimum risk(DFMR) of leakage into the reference cavity. Since the burst discs are DFMR, a single burst disc would suffice, without adding the two leak-into-reference cavity failure modes. A single DFMR burst disc is preferable. An Alpha Magnetic Spectrometer - 02 burst disc assembly, with three-in-series burst discs test failure, necessitated the deletion of one of the burst discs, will be presented. Payload relief valves require periodic retests were extended significantly beyond the normal one year retest period because of the reduced ISS down mass capability which followed the Columbia accident. The acceptability of the extended retest period was determined by analysis, materials stability, benign environment, relatively inert fluid exposure, etc.(The policy letter, NC4-02-205 Guidelines for Certification and Verification of Pressure System Control Hardware, that permitted this action will be provided even though this application is not recommended for extending relief valve annual retest requirements.) The first crack pressure of a relief valve after an extended inactive period can be higher than the set crack pressure. Extrapolation of the extended inactive period and increased crack pressure could result in ineffective over pressure protection. Thus, relief valves with a ring or lever for activation are recommended so the relief valve can periodically be verified to open, functionality verified and the extended relief valve retest period should be discouraged. Stainless Steel cylindrical poppet-in-cylindrical housing check valves should never be used in a fluid with ions for an extended period of time, because the poppet is vulnerable to seizing or not functioning as a relief valve, even though the specifications, crack pressure, reseat pressure, maximum flow, and reseat leak look very much like the specifications for a relief valve. The technical reasons for this avoidance of using check valves as a relief valve will be discussed. The presentation will be summarized and recommendations made.

Measuring Thermal Conductivity at LH2 Temperatures

NASA Technical Reports Server (NTRS)

Selvidge, Shawn; Watwood, Michael C.

2004-01-01

For many years, the National Institute of Standards and Technology (NIST) produced reference materials for materials testing. One such reference material was intended for use with a guarded hot plate apparatus designed to meet the requirements of ASTM C177-97, "Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus." This apparatus can be used to test materials in various gaseous environments from atmospheric pressure to a vacuum. It allows the thermal transmission properties of insulating materials to be measured from just above ambient temperature down to temperatures below liquid hydrogen. However, NIST did not generate data below 77 K temperature for the reference material in question. This paper describes a test method used at NASA's Marshall Space Flight Center (MSFC) to optimize thermal conductivity measurements during the development of thermal protection systems. The test method extends the usability range of this reference material by generating data at temperatures lower than 77 K. Information provided by this test is discussed, as are the capabilities of the MSFC Hydrogen Test Facility, where advanced methods for materials testing are routinely developed and optimized in support of aerospace applications.

A prospective randomized trial of postoperative pain following different insufflation pressures during gynecologic laparoscopy.

PubMed

Topçu, H O; Cavkaytar, S; Kokanalı, K; Guzel, A I; Islimye, M; Doganay, M

2014-11-01

To determine the effects of different intra-abdominal pressure values on visceral pain following gynecologic laparoscopic surgery in the Trendelenburg position. This randomized, controlled prospective trial was conducted at a tertiary education hospital and included 150 patients who underwent gynecologic laparoscopy with different abdominal insufflation pressures. There were 54 patients in the 8 mmHg low pressure group (LPG), 45 in the 12 mmHg standard pressure group (SPG), and 51 in the 15 mmHg high pressure group (HPG). We assessed mean age, body mass index (BMI), duration of surgery, analgesic consumption, length of hospital stay, amount of CO2 expended and volume of hemorrhage. Visceral pain and referred visceral pain were assessed 6, 12, and 24 h postoperatively using a visual analog scale (VAS). There was no significant difference in age, BMI, analgesic consumption or length of hospital stay among groups. The mean operative time and total CO2 expended during surgery were higher in the LPG compared with the SPG and HPG. The mean intensity of postoperative pain assessed by the VAS score at 6 and 12 h was less in the LPG than in the SPG and HPG and was reduced significantly at 12 h. VAS scores at 24 h in the LPG and SPG were lower than in the HPG. Pain is reduced by low insufflation pressure compared with standard and high insufflation pressure following gynecologic laparoscopic surgery in the Trendelenburg position. However, low insufflation pressure may result in longer operation times and increased hemorrhage. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effects of zero reference position on bladder pressure measurements: an observational study.

PubMed

Soler Morejón, Caridad De Dios; Lombardo, Tomás Ariel; Tamargo Barbeito, Teddy Osmin; Sandra, Barquín García

2012-07-05

Although the World Society for Abdominal Compartment Syndrome in its guidelines recommends midaxillary line (MAL) as zero reference level in intra-abdominal pressure (IAP) measurements in aiming at standardizing the technique, evidence supporting this suggestion is scarce. The aim of this study is to study if the zero reference position influences bladder pressure measurements as estimate for IAP. The IAP of 100 surgical patients was measured during the first 24 h of admission to the surgical intensive care unit of General Calixto Garcia Hospital in Havana (Cuba) following laparotomy. The period was January 2009 to January 2010. The IAP was measured twice with a six-hour interval using the transurethral technique with a priming volume of 25 ml. IAP was first measured with the zero reference level placed at MAL (IAPMAL), followed by a second measurement at the level of the symphysis pubis (SP) after 3 minutes (IAPSP). Correlations were made between IAP and body mass index (BMI), type of surgery, gender, and age. Mean IAPMAL was 8.5 ± 2.8 mmHg vs. IAPSP 6.5 ± 2.8 mmHg (p < 0.0001). The bias between measurements was 2.0 ± 1.5, 95% confidence interval of 1.4 to 3.0, upper limit of 4.9, lower limit of -0.9, and a percentage error of 35.1%. IAPMAL was consistently higher than IAPSP regardless of the type of surgery. The BMI correlated with IAP values regardless of the zero reference level (R2 = 0.4 and 0.3 with IAPMAL and IAPSP respectively, p < 0.0001). The zero reference level has an important impact on IAP measurement in surgical patients after laparotomy and can potentially lead to over or underestimation. Further anthropometric studies are needed with regard to the relative MAL and SP zero reference position in relation to the theoretical ideal reference level at midpoint of the abdomen. Until better evidence is available, MAL remains the recommended zero reference position due to its best anatomical localization at iliac crest.

Effects of zero reference position on bladder pressure measurements: an observational study

PubMed Central

2012-01-01

Background Although the World Society for Abdominal Compartment Syndrome in its guidelines recommends midaxillary line (MAL) as zero reference level in intra-abdominal pressure (IAP) measurements in aiming at standardizing the technique, evidence supporting this suggestion is scarce. The aim of this study is to study if the zero reference position influences bladder pressure measurements as estimate for IAP. Methods The IAP of 100 surgical patients was measured during the first 24 h of admission to the surgical intensive care unit of General Calixto Garcia Hospital in Havana (Cuba) following laparotomy. The period was January 2009 to January 2010. The IAP was measured twice with a six-hour interval using the transurethral technique with a priming volume of 25 ml. IAP was first measured with the zero reference level placed at MAL (IAPMAL), followed by a second measurement at the level of the symphysis pubis (SP) after 3 minutes (IAPSP). Correlations were made between IAP and body mass index (BMI), type of surgery, gender, and age. Results Mean IAPMAL was 8.5 ± 2.8 mmHg vs. IAPSP 6.5 ± 2.8 mmHg (p < 0.0001). The bias between measurements was 2.0 ± 1.5, 95% confidence interval of 1.4 to 3.0, upper limit of 4.9, lower limit of -0.9, and a percentage error of 35.1%. IAPMAL was consistently higher than IAPSP regardless of the type of surgery. The BMI correlated with IAP values regardless of the zero reference level (R2 = 0.4 and 0.3 with IAPMAL and IAPSP respectively, p < 0.0001). Conclusions The zero reference level has an important impact on IAP measurement in surgical patients after laparotomy and can potentially lead to over or underestimation. Further anthropometric studies are needed with regard to the relative MAL and SP zero reference position in relation to the theoretical ideal reference level at midpoint of the abdomen. Until better evidence is available, MAL remains the recommended zero reference position due to its best anatomical localization at iliac crest. PMID:22873414

Suggested techniques, equipment, and standards for the testing of hand insecticide-spraying equipment

PubMed Central

Hall, Lawrence B.

1955-01-01

The new demands placed upon application equipment by the introduction of modern insecticides have revealed the deficiencies of this equipment when required for continuous use on a large scale. If adequate equipment is to be produced, specifications must be based not only on basic materials tests but also on “use” tests, in which the conditions of field use are simulated. The author outlines suggested techniques to be followed and standards to be adopted in testing the performance of compression sprayers and allied equipment, with reference to the following features: compression-sprayer tank fatigue; tank impact; pump resistance to bursting; pump resistance to collapse; pump friction; cut-off valve durability; constant-pressure valves; cut-off valve actuation; hose flexure; hose tension and bursting-pressure; hose friction; gaskets, valve faces, and similar non-metallic parts; nozzle-orifice erosion; and nozzle pattern. ImagesFIG. 1FIG. 14FIG. 20 PMID:14364189

Calculating osmotic pressure of glucose solutions according to ASOG model and measuring it with air humidity osmometry.

PubMed

Wei, Guocui; Zhan, Tingting; Zhan, Xiancheng; Yu, Lan; Wang, Xiaolan; Tan, Xiaoying; Li, Chengrong

2016-09-01

The osmotic pressure of glucose solution at a wide concentration range was calculated using ASOG model and experimentally determined by our newly reported air humidity osmometry. The measurements from air humidity osmometry were compared with the well-established freezing point osmometry and ASOG model calculations at low concentrations and with only ASOG model calculations at high concentrations where no standard experimental method could serve as a reference for comparison. Results indicate that air humidity osmometry measurements are comparable to ASOG model calculations at a wide concentration range, while at low concentrations freezing point osmometry measurements provide better comparability with ASOG model calculations.

Sound pressure level in a municipal preschool

PubMed Central

Kemp, Adriana Aparecida Tahara; Delecrode, Camila Ribas; Guida, Heraldo Lorena; Ribeiro, André Knap; Cardoso, Ana Claúdia Vieira

2013-01-01

Summary Aim: To evaluate the sound pressure level to which preschool students are exposed. Method: This was a prospective, quantitative, nonexperimental, and descriptive study. To achieve the aim of the study we used an audio dosimeter. The sound pressure level (SPL) measurements were obtained for 2 age based classrooms. Preschool I and II. The measurements were obtained over 4 days in 8-hour sessions, totaling 1920 minutes. Results: Compared with established standards, the SPL measured ranged from 40.6 dB (A) to 105.8 dB (A). The frequency spectrum of the SPL was concentrated in the frequency range between 500 Hz and 4000 Hz. The older children produced higher SPLs than the younger ones, and the levels varied according to the activity performed. Painting and writing were the quietest activities, while free activities period and games were the noisiest. Conclusion: The SPLs measured at the preschool were higher and exceeded the maximum permitted level according to the reference standards. Therefore, the implementation of actions that aim to minimize the negative impact of noise in this environment is essential. PMID:25992013

Experimental feasibility study of estimation of the normalized central blood pressure waveform from radial photoplethysmogram.

PubMed

Zahedi, Edmond; Sohani, Vahid; Ali, M A Mohd; Chellappan, Kalaivani; Beng, Gan Kok

2015-01-01

The feasibility of a novel system to reliably estimate the normalized central blood pressure (CBPN) from the radial photoplethysmogram (PPG) is investigated. Right-wrist radial blood pressure and left-wrist PPG were simultaneously recorded in five different days. An industry-standard applanation tonometer was employed for recording radial blood pressure. The CBP waveform was amplitude-normalized to determine CBPN. A total of fifteen second-order autoregressive models with exogenous input were investigated using system identification techniques. Among these 15 models, the model producing the lowest coefficient of variation (CV) of the fitness during the five days was selected as the reference model. Results show that the proposed model is able to faithfully reproduce CBPN (mean fitness = 85.2% ± 2.5%) from the radial PPG for all 15 segments during the five recording days. The low CV value of 3.35% suggests a stable model valid for different recording days.

Development of a standard reference material containing 22 chlorinated hydrocarbon gases at 1 μmol/mol in nitrogen.

PubMed

Li, Ning; Du, Jian; Yang, Jing; Fan, Qiang; Tian, Wen

2017-11-01

A gas standard mixture containing 22 chlorinated hydrocarbons in high purity nitrogen was prepared using a two-step weighing method and a gasifying apparatus developed in-house. The concentration of each component was determined using a gas chromatograph with flame ionization detection (GC/FID). Linear regression analysis of every component was performed using the gas standard mixture with concentrations ranging from 1 to 10 μmol/mol, showing the complete gasification of volatile organic compound (VOCs) species in a selected cylinder. Repeatability was also examined to ensure the reliability of the preparation method. In addition, no significant difference was observed between domestic treated and imported treated cylinders, which were conducive to reduction of the cost of raw materials. Moreover, the results of stability testing at different pressures and long-term stability tests indicated that the gas standard at 1 μmol/mol level with relative expanded uncertainties of 5% was stable above 2 MPa for a minimum of 12 months. Finally, a quantity comparison was conducted between the gas standard and a commercial gas standard from Scott Specialty Gases (now Air Liquide America Specialty Gases). The excellent agreement of every species suggested the favorable accuracy of our gas standard. Therefore, this reference material can be applied to routine observation of VOCs and for other purposes.

Indicator system provides complete data of engine cylinder pressure variation

NASA Technical Reports Server (NTRS)

Mc Jones, R. W.; Morgan, N. E.

1966-01-01

Varying reference pressure used together with a balanced pressure pickup /a diaphragm switch/ to switch the electric output of the pressure transducer in a reference pressure line obtains precise engine cylinder pressure data from a high speed internal combustion engine.

Measurements of Flow Turbulence in the NASA Langley Transonic Dynamics Tunnel

NASA Technical Reports Server (NTRS)

Wiesman, Carol D.; Sleeper, Robert K.

2005-01-01

An assessment of the flow turbulence in the NASA Langley Transonic Dynamics Tunnel (TDT) was conducted during calibration activities following the facility conversion from a Freon-12 heavy-gas test medium to an R134a heavy-gas test medium. Total pressure, static pressure, and acoustic pressure levels were measured at several locations on a stingmounted rake. The test measured wall static pressures at several locations although this paper presents only those from one location. The test used two data acquisition systems, one sampling at 1000 Hz and the second sampling at 125 000 Hz, for acquiring time-domain data. This paper presents standard deviations and power spectral densities of the turbulence points throughout the wind tunnel envelope in air and R134a. The objective of this paper is to present the turbulence characteristics for the test section. No attempt is made to assess the causes of the turbulence. The present paper looks at turbulence in terms of pressure fluctuations. Reference 1 looked at tunnel turbulence in terms of velocity fluctuations.

Comparison of measurement standards of the acoustic pressure in air in the low frequency range: COOMET.AUV.A-K2

NASA Astrophysics Data System (ADS)

Chalyy, V.

2011-01-01

A bilateral regional comparison of national microphone standards from 2 Hz to 250 Hz was carried out between the DP NDI 'Systema' (Ukraine) and the VNIIFTRI (Russia) from July to September 2009. The comparison, COOMET.AUV.A-K2, was based on the pressure calibration of laboratory standard microphones type LSIP. The comparison results have been linked to the established key comparison reference value (KCRV) of CCAUV.A-K2. The degrees of equivalence, expressed as the deviation from the established KCRV and its expanded uncertainty (k = 2), have been determined, and the comparison result is in agreement with the KCRV within the estimated uncertainties at all employed frequencies. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Effect of inlet temperature on the performance of a catalytic reactor. [air pollution control

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1978-01-01

A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m/s, and adiabatic combustion temperatures in the range 1100 to 1400 K. The combustion efficiency was calculated from measurements of carbon monoxide and unburned hydrocarbon emissions. Nitrogen oxide emissions and reactor pressure drop were also measured. At a reference velocity of 10 m/s, the CO and unburned hydrocarbons emissions, and, therefore, the combustion efficiency, were independent of inlet temperature. At an inlet temperature of 1000 K, they were independent of reference velocity. Nitrogen oxides emissions resulted from conversion of the small amount (135 ppm) of fuel-bound nitrogen in the fuel. Up to 90 percent conversion was observed with no apparent effect of any of the test variables. For typical gas turbine operating conditions, all three pollutants were below levels which would permit the most stringent proposed automotive emissions standards to be met.

Manual therapy in the management of a patient with a symptomatic Morton's Neuroma: A case report.

PubMed

Sault, Josiah D; Morris, Matthew V; Jayaseelan, Dhinu J; Emerson-Kavchak, Alicia J

2016-02-01

Patients with Morton's neuroma are rarely referred to physical therapy. This case reports the resolution of pain, increase in local pressure pain thresholds, and improvement of scores on the Lower Extremity Functional Scale and Foot and Ankle Ability Measure following a course of joint based manual therapy for a patient who had failed standard conservative medical treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

In vitro comparison of intra-abdominal hypertension development after different temporary abdominal closure techniques.

PubMed

Benninger, Emanuel; Labler, Ludwig; Seifert, Burkhardt; Trentz, Otmar; Menger, Michael D; Meier, Christoph

2008-01-01

To compare volume reserve capacity (VRC) and development of intra-abdominal hypertension after different in vitro temporary abdominal closure (TAC) techniques. A model of the abdomen was designed. The abdominal wall was simulated with polychloroprene, a synthetic rubber compound. A lentil-shaped defect of 150 cm(2) was cut into the anterior aspect of the abdominal wall. TAC of this defect was performed by a zipper system (ZS), a bag silo closure (BSC), or a vacuum assisted closure (VAC) with subatmospheric pressures ranging from 0- to 200 mmHg. The model with intact abdominal wall served as reference. The model was filled with water to baseline level. The intra-abdominal pressure was increased in 2 mmHg steps from baseline level (6 mmHg) to 40 mmHg by adding volume to the system according to a standardized protocol. VRC with corresponding intra-abdominal pressure were analyzed and compared for the different TAC techniques. VRC was the highest after BSC at all pressure levels studied (P < 0.05). VAC and ZS resulted in significantly lower VRC compared with BSC and reference (P < 0.05). The magnitude of negative pressure on the VAC did not significantly influence the VRC. In the present in vitro model, BSC demonstrated the highest VRC of all evaluated TAC techniques. Different levels of subatmospheric pressures applied to the VAC did not affect VRC. The results for ZS and VAC indicate that these TAC techniques may increase the risk for recurrent intra-abdominal hypertension and should therefore not be used in high-risk patients during the initial phase after abdominal decompression.

Simultaneous identification and quantification of new psychoactive substances in blood by GC-APCI-QTOFMS coupled to nitrogen chemiluminescence detection without authentic reference standards.

PubMed

Ojanperä, Ilkka; Mesihää, Samuel; Rasanen, Ilpo; Pelander, Anna; Ketola, Raimo A

2016-05-01

A novel platform is introduced for simultaneous identification and quantification of new psychoactive substances (NPS) in blood matrix, without the necessity of using authentic reference standards. The instrumentation consisted of gas chromatography (GC) coupled to nitrogen chemiluminescence detection (NCD) and atmospheric pressure chemical ionization quadrupole time-of-flight mass spectrometry (APCI-QTOFMS). In this concept, the GC flow is divided in appropriate proportions between NCD for single-calibrant quantification, utilizing the detector's equimolar response to nitrogen, and QTOFMS for accurate mass-based identification. The principle was proven by analyzing five NPS, bupropion, desoxypipradrol (2-DPMP), mephedrone, methylone, and naphyrone, in sheep blood. The samples were spiked with the analytes post-extraction to avoid recovery considerations at this point. All the NPS studies produced a protonated molecule in APCI resulting in predictable fragmentation with high mass accuracy. The N-equimolarity of quantification by NCD was investigated by using external calibration with the secondary standard caffeine at five concentration levels between 0.17 and 1.7 mg/L in blood matrix as five replicates. The equimolarity was on average 98.7%, and the range of individual equimolarity determinations was 76.7-130.1%. The current analysis platform affords a promising approach to instant simultaneous qualitative and quantitative analysis of drugs in the absence of authentic reference standards, not only in forensic and clinical toxicology but also in other bioanalytical applications.

Comparison of the Omron RS6 wrist blood pressure monitor with the positioning sensor on or off with a standard mercury sphygmomanometer.

PubMed

Deutsch, Cornelia; Krüger, Ralf; Saito, Kanako; Yamashita, Shingo; Sawanoi, Yukiya; Beime, Beate; Bramlage, Peter

2014-10-01

The aim of the present study was to evaluate the measurement accuracy of Omron RS6 with positioning sensor on (PSON) in comparison with Omron RS6 with positioning sensor off (PSOFF). The Omron RS6 has passed the 2010 version of the European Society of Hypertension International Protocol previously. A total of 85 adult participants (39 male and 46 female) were recruited. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were sequentially measured using a standard mercury reference sphygmomanometer (ERKA 3000; two observers) and Omron RS6 with PSON or PSOFF. A total of 85 participants (39 men, 46 women) were included in this study, with a mean age of 53.5±16.4 years. SBP at entry was 133.0±19.9 mmHg and DBP was 81.3±11.8 mmHg. The two observers for SBP and DBP measurements were in good agreement, with agreements of -0.2±1.5 mmHg for SBP and -0.2±1.5 mmHg for DBP, respectively. The mean difference between PSON readings and readings from the standard device was -2.6±6.1 mmHg for SBP and -1.4±4.8 mmHg for DBP. The differences in PSOFF readings were -4.5±6.9 and -3.2±5.4 mm Hg, respectively (P<0.01; PSON vs. PSOFF). A higher proportion of patients had a small deviation (≤5 mmHg) from the reference device when the positioning sensor was on (65 vs. 54% for SBP and 76 vs. 65% for DBP readings). Using the positioning sensor, the variation in wrist height compared with PSOFF decreased. The Omron RS6 position sensor is an important function for a wrist device that improves measurement accuracy by decreasing variations in wrist height.

Cross-validation of the osmotic pressure based on Pitzer model with air humidity osmometry at high concentration of ammonium sulfate solutions.

PubMed

Wang, Xiao-Lan; Zhan, Ting-Ting; Zhan, Xian-Cheng; Tan, Xiao-Ying; Qu, Xiao-You; Wang, Xin-Yue; Li, Cheng-Rong

2014-01-01

The osmotic pressure of ammonium sulfate solutions has been measured by the well-established freezing point osmometry in dilute solutions and we recently reported air humidity osmometry in a much wider range of concentration. Air humidity osmometry cross-validated the theoretical calculations of osmotic pressure based on the Pitzer model at high concentrations by two one-sided test (TOST) of equivalence with multiple testing corrections, where no other experimental method could serve as a reference for comparison. Although more strict equivalence criteria were established between the measurements of freezing point osmometry and the calculations based on the Pitzer model at low concentration, air humidity osmometry is the only currently available osmometry applicable to high concentration, serves as an economic addition to standard osmometry.

Bilateral comparison of 10 V standards between the NSAI - NML (Ireland) and the BIPM, February 2016 (part of the ongoing BIPM key comparison BIPM.EM-K11.b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Power, O.; Stock, M.

2016-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland - National Metrology Laboratory (NSAI - NML), Dublin, Ireland, was carried out in January and February 2016. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM7 (Z7) and BIPM9 (Z9), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by NSAI - NML, at the level of 10 V, at NSAI - NML, UNML, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 31 of January 2016. UNML - UBIPM = + 0.22 μV uc = 1.35 μV , at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral Comparison of 10 V Standards between the NSAI - NML (Ireland) and the BIPM, March 2015 (part of the ongoing BIPM key comparison BIPM.EM-K11.b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Stock, M.; Power, O.

2015-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland - National Metrology Laboratory (NSAI - NML), Dublin, Ireland, was carried out in February and March 2015. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM6 (Z6) and BIPMC (ZC), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final resultof the comparison is presented as the difference between the values assigned to DC voltage standards by NSAI - NML, at the level of 10 V,at NSAI - NML, UNML, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 24 February 2015. UNML - UBIPM = - 0.82 mV; uc = 1.35 mV , at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Diagnostic effectiveness of quantitative [18F]flutemetamol PET imaging for detection of fibrillar amyloid β using cortical biopsy histopathology as the standard of truth in subjects with idiopathic normal pressure hydrocephalus

PubMed Central

2014-01-01

Introduction PET imaging of amyloid-β (Aβ) in vivo holds promise for aiding in earlier diagnosis and intervention in Alzheimer’s disease (AD) and mild cognitive impairment. AD-like Aβ pathology is a common comorbidity in patients with idiopathic normal pressure hydrocephalus (iNPH). Fifty patients with iNPH needing ventriculo-peritoneal shunting or intracranial pressure monitoring underwent [18F]flutemetamol PET before (N = 28) or after (N = 22) surgery. Cortical uptake of [18F]flutemetamol was assessed visually by blinded reviewers, and also quantitatively via standard uptake value ratio (SUVR) in specific neocortical regions in relation to either cerebellum or pons reference region: the cerebral cortex of (prospective studies) or surrounding (retrospective studies) the biopsy site, the contralateral homolog, and a calculated composite brain measure. Aβ pathology in the biopsy specimen (standard of truth [SoT]) was measured using Bielschowsky silver and thioflavin S plaque scores, percentage area of grey matter positive for monoclonal antibody to Aβ (4G8), and overall pathology impression. We set out to find (1) which pair(s) of PET SUVR and pathology SoT endpoints matched best, (2) whether quantitative measures of [18F]flutemetamol PET were better for predicting the pathology outcome than blinded image examination (BIE), and (3) whether there was a better match between PET image findings in retrospective vs. prospective studies. Results Of the 24 possible endpoint/SoT combinations, the one with composite-cerebellum SUVR and SoT based on overall pathology had the highest Youden index (1.000), receiver operating characteristic area under the curve (1.000), sensitivity (1.000), specificity (1.000), and sum of sensitivity and specificity for the pooled data as well as for the retrospective and prospective studies separately (2.00, for all 3). The BIE sum of sensitivity and specificity, comparable to that for quantitation, was highest using Bielschowsky silver as SoT for all SUVRs (ipsilateral, contralateral, and composite, for both reference regions). The composite SUVR had a 100% positive predictive value (both reference regions) for the overall pathology diagnosis. All SUVRs had a 100% negative predictive value for the Bielschowsky silver result. Conclusion Bielschowsky silver stain and overall pathology judgment showed the strongest associations with imaging results. PMID:24755237

Simultaneous validation of the SunTech CT40 automated blood pressure measurement device by the 1993 British Hypertension Society protocol and the Association for the Advancement of Medical Instrumentation/International Organization for Standardization 81060-2: 2013 standard.

PubMed

Polo Friz, Hernan; Punzi, Veronica; Petri, Francesco; Orlandi, Riccardo; Maggiolini, Daniele; Polo Friz, Melisa; Primitz, Laura; Vighi, Giuseppe

2017-10-01

This study aimed to perform a simultaneous, third-party, independent validation of the oscillometric SunTech CT40 device for blood pressure (BP) measurement, according to the 1993 protocol of the British Hypertension Society and the standard of the Association for the Advancement of Medical Instrumentation (AAMI)/the International Organization for Standardization (ISO) 81060-2:2013. Patient recruitment, study procedures, and data analysis followed the recommendations stated by the protocols. The study was approved by the institutional review board. A total of 94 participants were included, 52 (55.3%) women, mean±SD age: 63.1±18.0 years, mean±SD arm circumference: 35.0±9.0 cm. The average of observers' entry BPs was 146.9±37.2 mmHg for systolic blood pressure (SBP) and 82.2±22.1 mmHg for diastolic blood pressure (DBP). Differences between the standard measurement and the test device within 5, 10, and 15 mmHg, for the better observer, were 79.4, 96.5, and 100.0% for SBP and 82.6, 97.5, and 100.0% for DBP, respectively. The mean±SD differences between the readings obtained using the test device and those obtained by the observers (AAMI/ISO 81060-2:2013 standard criterion 1) were 0.3±5.0 mmHg (SBP) and -0.8±4.3 mmHg (DBP), and the mean±SD differences between average of reference readings and average of test device readings in each patient (criterion 2) were 0.3±3.9 and -0.8±3.5 mmHg for SBP and DBP, respectively. The CT40 BP device achieved A/A grade of the British Hypertension Society protocol and fulfilled the requirements (criteria 1 and 2) of the AAMI/ISO standard. CT40 can be recommended for BP measurement in adults.

Infant CPAP for low-income countries: An experimental comparison of standard bubble CPAP and the Pumani system.

PubMed

Falk, Markus; Donaldsson, Snorri; Drevhammar, Thomas

2018-01-01

Access to inexpensive respiratory support to newborn infants improves survival in low-income countries. Standard bubble continuous positive airway pressure (CPAP) has been extensively used worldwide for more than 30 years. One project aimed at providing affordable CPAP is the Pumani system developed by Rice 360°. Compared to standard bubble CPAP the system has an unconventional design. The aim was to compare the Pumani system with two traditional bubble CPAP systems, focusing on in-vitro performance and safety. The Pumani system was compared to traditional bubble CPAP from Fisher & Paykel (Auckland, New Zealand) and Diamedica (Devon, United Kingdom). The systems were tested using static flow resistance and simulated breathing for a range of fresh gas flows and submersion levels. There were large differences between the Pumani CPAP and the conventional bubble CPAP systems. The Pumani system was not pressure stable, had high resistance and high imposed work of breathing. It was not possible to use submersion depth to adjust CPAP without accounting for fresh gas flow. The Pumani design is novel and not similar to any previously described CPAP system. The main mechanism for CPAP generation was resistance, not submersion depth. The system should therefore not be referred to as bubble CPAP. The clinical consequences of its pressure instability and high imposed work of breathing are not known and trials on outcome and safety are needed.

Calibration of Relative Humidity Devices in Low-pressure, Low-temperature CO2 Environment

NASA Astrophysics Data System (ADS)

Genzer, Maria; Polkko, Jouni; Nikkanen, Timo; Hieta, Maria; Harri, Ari-Matti

2017-04-01

Calibration of relative humidity devices requires in minimum two humidity points - dry (0%RH) and (near)saturation (95-100%RH) - over the expected operational temperature and pressure range of the device. In terrestrial applications these are relatively easy to achieve using for example N2 gas as dry medium, and water vapor saturation chambers for producing saturation and intermediate humidity points. But for example in applications intended for meteorological measurements on Mars there is a need to achieve at least dry and saturation points in low-temperature, low-pressure CO2 environment. We have developed a custom-made, small, relatively low-cost calibration chamber able to produce both dry points and saturation points in Martian range pressure CO2, in temperatures down to -70°C. The system utilizes a commercially available temperature chamber for temperature control, vacuum vessels and pumps. The main pressure vessel with the devices under test inside is placed inside the temperature chamber, and the pressure inside is controlled by pumps and manual valves and monitored with a commercial pressure reference with calibration traceable to national standards. Air, CO2, or if needed another gas like N2, is used for filling the vessel until the desired pressure is achieved. Another pressure vessel with a dedicated pressure pump is used as the saturation chamber. This vessel is placed in the room outside the temperature chamber, partly filled with water and used for achieving saturated water vapor in room-temperature low-pressure environment. The saturation chamber is connected to the main pressure vessel via valves. In this system dry point, low-pressure CO2 environment is achieved by filling the main pressure vessel with dry CO2 gas until the desired pressure is achieved. A constant flow of gas is maintained with the pump and valves and monitored with the pressure reference. The saturation point is then achieved by adding some water vapor from the saturation chamber to the main pressure vessel. The amount of water vapor added is also monitored with the pressure reference. For example in -70°C, very small absolute amount of water vapor corresponding to 1 Pa [1][2] pressure rise in the main chamber results in humidity saturation. As the flow of both CO2 and water vapor is kept constant, the main chamber is served with water vapor all the time, keeping the uniform saturation conditions inside the vessel even if some of the water freezes on the vessel and pipe walls. [1] Goff, J. A., and S. Gratch (1946) Low-pressure properties of water from -160 to 212 °F, Transactions of the American Society of Heating and Ventilating Engineers [2] Goff, J. A. (1957) Saturation pressure of water on the new Kelvin temperature scale, Transactions of the American Society of Heating and Ventilating Engineers

Bilateral Comparison of 1 V and 10 V Standards between the SMD (Belgium) and the BIPM October to December 2014 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Stock, M.; Vlad, D.

2015-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Service Métrologie—Metrologische Dienst (SMD), Brussel, Belgium, was carried out from October to November 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM4 (Z4) and BIPM5 (Z5), were transported by freight to SMD and also back to BIPM. At SMD, the reference standard for DC voltage is a Josephson Voltage Standard (JVS). The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at SMD, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned toDC voltage standards by SMD, at the level of 1.018 V and 10 V, at SMD, USMD, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 5 November 2014. USMD - UBIPM = 0.14 mV; uc = 0.07 mV, at 1 V USMD - UBIPM = 0.09 mV; uc = 0.49 mV , at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at SMD, based on KJ-90, and the uncertainty related to the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral Comparison of 1 V and 10 V Standards between the JV (Norway) and the BIPM, January to February 2015 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Stock, M.; Sengebush, F.

2015-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Justervesenet (JV), Kjeller, Norway, was carried out from January to February 2015. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM4 (Z4) and BIPM5 (Z5), were transported by freight to JV and also back to BIPM. At JV, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at JV, withthe Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned toDC voltage standards by JV, at the level of 1.018 V and 10 V, at JV, UJV, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 28 January 2015. UJV - UBIPM = 0.23 μV uc = 0.03 μV , at 1 V UJV - UBIPM = 0.63 μV uc = 0.28 μV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at JV, based on KJ-90, and the uncertainty related to the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral Comparison of 1 V and 10 V Standards between the NIMT (Thailand) and the BIPM October to December 2014 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Stock, M.; Pimsut, S.

2015-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the National Institute of Metrology (Thailand), NIMT, was carried out from October to December 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPMA (ZA) and BIPM6 (Z6), were transported by freight to NIMT and back to BIPM. At NIMT, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at NIMT, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned toDC voltage standards by NIMT, at the level of 1.018 V and 10 V, at NIMT, UNIMT, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 23 November 2014. UNIMT - UBIPM = 0.16 mV; uc = 0.14 mV, at 1 V UNIMT - UBIPM = - 0.03 mV; uc = 0.11 mV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NIMT, based on KJ-90, and the uncertainty related to the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Body size and growth: the significance of chronic malnutrition among the Casiguran Agta.

PubMed

De Souza, Roberta G

2006-01-01

The Agta are a short statured, hunter-gatherer population who have been living under demographic and environmental stress. This article shows the influence of these factors and the resulting nutritional deficiency on the anthropometric measurements and mortality of Agta individuals. The joint analysis of cross-sectional measurements of Agta children and adults and of the mortality schedules in this population aims to stress the influence of environmental pressures on the ongoing evolution of short stature. Recumbent length, height, weight, mid-upper arm circumference, and triceps skinfolds were taken using standard methods from a total of 253 Agta individuals. Exact or nearly exact ages were taken from a long-term demographic database. z-Scores and growth curves were calculated using the NutStat program and 2000 CDC reference. Mortality schedules are from published material, improved through interviews in the field. Agta individuals are both short and thin when compared to other populations. Thirty-four per cent of the adults are under-nourished, while 17% of the children are wasted, according to international standards. A major and delayed peak of mortality in early infancy overlaps with a period of average decrease in body length in relation to the reference. Demographic indicators of poor health-related quality of life are consistent with slowed patterns of growth observed, stressing the importance of environmental pressure in maintaining the short stature of the Agta population.

Living cell manipulation, manageable sampling, and shotgun picoliter electrospray mass spectrometry for profiling metabolites.

PubMed

Gholipour, Yousef; Erra-Balsells, Rosa; Hiraoka, Kenzo; Nonami, Hiroshi

2013-02-01

A modified cell pressure probe and an online Orbitrap mass spectrometer were used to sample in situ plant single cells without any additional manipulation. The cell pressure probe, a quartz capillary tip filled with an oil mixture, was penetrated to various depths into parenchyma cells of tulip bulb scale, followed by a hydraulic continuity test to determine the exact location of the tip inside target cells. The operation was conducted under a digital microscope, and the capillary tip was photographed to calculate the volume of the cell sap sucked. The cell sap sample was then directly nebulized/ionized under high-voltage conditions at the entrance of the mass spectrometer. Several sugars, amino acids, organic acids, vitamins, fatty acids, and secondary metabolites were detected. Because picoliter solutions can be accurately handled and measured, known volumes of standard solutions can be added to cell sap samples inside the capillary tip to be used as references for metabolite characterization and relative quantitation. The high precision and sensitivity of the cell pressure probe and Orbitrap mass spectrometer allow for the manipulation and analysis of both femtoliter cell sap samples and standard solutions. Copyright © 2012 Elsevier Inc. All rights reserved.

Method and Apparatus for Non-Invasive Measurement of Changes in Intracranial Pressure

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor)

2004-01-01

A method and apparatus for measuring intracranial pressure. In one embodiment, the method comprises the steps of generating an information signal that comprises components (e.g., pulsatile changes and slow changes) that are related to intracranial pressure and blood pressure, generating a reference signal comprising pulsatile components that are solely related to blood pressure, processing the information and reference signals to determine the pulsatile components of the information signal that have generally the same phase as the pulsatile components of the reference signal, and removing from the information signal the pulsatile components determined to have generally the same phase as the pulsatile components of the reference signal so as to provide a data signal having components wherein substantially all of the components are related to intracranial pressure.

Accuracy and precision of polar lower stratospheric temperatures from reanalyses evaluated from A-Train CALIOP and MLS, COSMIC GPS RO, and the equilibrium thermodynamics of supercooled ternary solutions and ice clouds

NASA Astrophysics Data System (ADS)

Lambert, Alyn; Santee, Michelle L.

2018-02-01

We investigate the accuracy and precision of polar lower stratospheric temperatures (100-10 hPa during 2008-2013) reported in several contemporary reanalysis datasets comprising two versions of the Modern-Era Retrospective analysis for Research and Applications (MERRA and MERRA-2), the Japanese 55-year Reanalysis (JRA-55), the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-I), and the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (NCEP-CFSR). We also include the Goddard Earth Observing System model version 5.9.1 near-real-time analysis (GEOS-5.9.1). Comparisons of these datasets are made with respect to retrieved temperatures from the Aura Microwave Limb Sounder (MLS), Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) Global Positioning System (GPS) radio occultation (RO) temperatures, and independent absolute temperature references defined by the equilibrium thermodynamics of supercooled ternary solutions (STSs) and ice clouds. Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations of polar stratospheric clouds are used to determine the cloud particle types within the Aura MLS geometric field of view. The thermodynamic calculations for STS and the ice frost point use the colocated MLS gas-phase measurements of HNO3 and H2O. The estimated bias and precision for the STS temperature reference, over the 68 to 21 hPa pressure range, are 0.6-1.5 and 0.3-0.6 K, respectively; for the ice temperature reference, they are 0.4 and 0.3 K, respectively. These uncertainties are smaller than those estimated for the retrieved MLS temperatures and also comparable to GPS RO uncertainties (bias < 0.2 K, precision > 0.7 K) in the same pressure range. We examine a case study of the time-varying temperature structure associated with layered ice clouds formed by orographic gravity waves forced by flow over the Palmer Peninsula and compare how the wave amplitudes are reproduced by each reanalysis dataset. We find that the spatial and temporal distribution of temperatures below the ice frost point, and hence the potential to form ice polar stratospheric clouds (PSCs) in model studies driven by the reanalyses, varies significantly because of the underlying differences in the representation of mountain wave activity. High-accuracy COSMIC temperatures are used as a common reference to intercompare the reanalysis temperatures. Over the 68-21 hPa pressure range, the biases of the reanalyses with respect to COSMIC temperatures for both polar regions fall within the narrow range of -0.6 K to +0.5 K. GEOS-5.9.1, MERRA, MERRA-2, and JRA-55 have predominantly cold biases, whereas ERA-I has a predominantly warm bias. NCEP-CFSR has a warm bias in the Arctic but becomes substantially colder in the Antarctic. Reanalysis temperatures are also compared with the PSC reference temperatures. Over the 68-21 hPa pressure range, the reanalysis temperature biases are in the range -1.6 to -0.3 K with standard deviations ˜ 0.6 K for the CALIOP STS reference, and in the range -0.9 to +0.1 K with standard deviations ˜ 0.7 K for the CALIOP ice reference. Comparisons of MLS temperatures with the PSC reference temperatures reveal vertical oscillations in the MLS temperatures and a significant low bias in MLS temperatures of up to 3 K.

New Standards for Diagnosing Hypertension Are Met with Skepticism | Poster

Cancer.gov

Members of the Eighth Joint National Committee recently released new standards for treating hypertension, also referred to as high blood pressure (BP). The new standards do not recommend treatment changes for individuals under 60 years of age. However, treatment changes were recommended for people over the age of 60 who do not have conditions such as diabetes or chronic kidney disease (CKD), but whose BP numbers are 150/90 or higher. This BP threshold is up from the previously recommended threshold of 140/90. The panel also recommended that for people over 60 years of age who have diabetes or CKD, treatment should begin when BP is 140/90, which is an increase from 130/80. Treatment may involve lifestyle changes and/or medication to bring the BP numbers into a healthy range.

Establishing reference values for central blood pressure and its amplification in a general healthy population and according to cardiovascular risk factors.

PubMed

Herbert, Annie; Cruickshank, John Kennedy; Laurent, Stéphane; Boutouyrie, Pierre

2014-11-21

Estimated central systolic blood pressure (cSBP) and amplification (Brachial SBP-cSBP) are non-invasive measures potentially prognostic of cardiovascular (CV) disease. No worldwide, multiple-device reference values are available. We aimed to establish reference values for a worldwide general population standardizing between the different available methods of measurement. How these values were significantly altered by cardiovascular risk factors (CVRFs) was then investigated. Existing data from population surveys and clinical trials were combined, whether published or not. Reference values of cSBP and amplification were calculated as percentiles for 'Normal' (no CVRFs) and 'Reference' (any CVRFs) populations. We included 45,436 subjects out of 82,930 that were gathered from 77 studies of 53 centres. Included subjects were apparently healthy, not treated for hypertension or dyslipidaemia, and free from overt CV disease and diabetes. Values of cSBP and amplification were stratified by brachial blood pressure categories and age decade in turn, both being stratified by sex. Amplification decreased with age and more so in males than in females. Sex was the most powerful factor associated with amplification with 6.6 mmHg (5.8-7.4) higher amplification in males than in females. Amplification was marginally but significantly influenced by CVRFs, with smoking and dyslipidaemia decreasing amplification, but increased with increasing levels of blood glucose. Typical values of cSBP and amplification in a healthy population and a population free of traditional CVRFs are now available according to age, sex, and brachial BP, providing values included from different devices with a wide geographical representation. Amplification is significantly influenced by CVRFs, but differently in men and women. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Determination of osmium concentrations and (187)Os/(188)Os of crude oils and source rocks by coupling high-pressure, high-temperature digestion with sparging OsO(4) into a multicollector inductively coupled plasma mass spectrometer.

PubMed

Sen, Indra S; Peucker-Ehrenbrink, Bernhard

2014-03-18

The (187)Os/(188)Os ratio that is based on the β(-)-decay of (187)Re to (187)Os (t1/2 = 41.6 billion years) is widely used to investigate petroleum system processes. Despite its broad applicability to studies of hydrocarbon deposits worldwide, a suitable matrix-matched reference material for Os analysis does not exist. In this study, a method that enables Os isotope measurement of crude oil with in-line Os separation and purification from the sample matrix is proposed. The method to analyze Os concentration and (187)Os/(187)Os involves sample digestion under high pressure and high temperature using a high pressure asher (HPA-S, Anton Paar), sparging of volatile osmium tetroxide from the sample solution, and measurements using multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). This methods significantly reduced the total procedural time compared to conventional Carius tube digestion followed by Os separation and purification using solvent extraction, microdistillation and N-TIMS analysis. The method yields Os concentration (28 ± 4 pg g(-1)) and (187)Os/(188)Os (1.62 ± 0.15) of commercially available crude oil reference material NIST 8505 (1 S.D., n = 6). The reference material NIST 8505 is homogeneous with respect to Os concentration at a test portion size of 0.2 g. Therefore, (187)Os/(188)Os composition and Os concentration of NIST 8505 can serve as a matrix-matched reference material for Os analysis. Data quality was assessed by repeated measurements of the USGS shale reference material SCo-1 (sample matrix similar to petroleum source rock) and the widely used Liquid Os Standard solution (LOsSt). The within-laboratory reproducibility of (187)Os/(188)Os for a 5 pg of LOsSt solution, analyzed with this method over a period of 12 months was ∼1.4% (1 S.D., n = 26), respectively.

New Equations for the Sublimation Pressure and Melting Pressure of H2O Ice Ih

NASA Astrophysics Data System (ADS)

Wagner, Wolfgang; Riethmann, Thomas; Feistel, Rainer; Harvey, Allan H.

2011-12-01

New reference equations, adopted by the International Association for the Properties of Water and Steam (IAPWS), are presented for the sublimation pressure and melting pressure of ice Ih as a function of temperature. These equations are based on input values derived from the phase-equilibrium condition between the IAPWS-95 scientific standard for thermodynamic properties of fluid H2O and the equation of state of H2O ice Ih adopted by IAPWS in 2006, making them thermodynamically consistent with the bulk-phase properties. Compared to the previous IAPWS formulations, which were empirical fits to experimental data, the new equations have significantly less uncertainty. The sublimation-pressure equation covers the temperature range from 50 K to the vapor-liquid-solid triple point at 273.16 K. The ice Ih melting-pressure equation describes the entire melting curve from 273.16 K to the ice Ih-ice III-liquid triple point at 251.165 K. For completeness, we also give the IAPWS melting-pressure equation for ice III, which is slightly adjusted to agree with the ice Ih melting-pressure equation at the corresponding triple point, and the unchanged IAPWS melting-pressure equations for ice V, ice VI, and ice VII.

Final report on the key comparison CCM.P-K4.2012 in absolute pressure from 1 Pa to 10 kPa

NASA Astrophysics Data System (ADS)

Ricker, Jacob; Hendricks, Jay; Bock, Thomas; Dominik, Pražák; Kobata, Tokihiko; Torres, Jorge; Sadkovskaya, Irina

2017-01-01

The report summarizes the Consultative Committee for Mass (CCM) key comparison CCM.P-K4.2012 for absolute pressure spanning the range of 1 Pa to 10 000 Pa. The comparison was carried out at six National Metrology Institutes (NMIs), including National Institute of Standards and Technology (NIST), Physikalisch-Technische Bundesanstalt (PTB), Czech Metrology Institute (CMI), National Metrology Institute of Japan (NMIJ), Centro Nacional de Metrología (CENAM), and DI Mendeleyev Institute for Metrology (VNIIM). The comparison was made via a calibrated transfer standard measured at each of the NMIs facilities using their laboratory standard during the period May 2012 to September 2013. The transfer package constructed for this comparison preformed as designed and provided a stable artifact to compare laboratory standards. Overall the participants were found to be statistically equivalent to the key comparison reference value. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Turbulent Kinetic Energy Measurement Using Phase Contrast MRI for Estimating the Post-Stenotic Pressure Drop: In Vitro Validation and Clinical Application

PubMed Central

Ha, Hojin; Kim, Guk Bae; Kweon, Jihoon; Huh, Hyung Kyu; Lee, Sang Joon; Koo, Hyun Jung; Kang, Joon-Won; Lim, Tae-Hwan; Kim, Dae-Hee; Kim, Young-Hak

2016-01-01

Background Although the measurement of turbulence kinetic energy (TKE) by using magnetic resonance imaging (MRI) has been introduced as an alternative index for quantifying energy loss through the cardiac valve, experimental verification and clinical application of this parameter are still required. Objectives The goal of this study is to verify MRI measurements of TKE by using a phantom stenosis with particle image velocimetry (PIV) as the reference standard. In addition, the feasibility of measuring TKE with MRI is explored. Methods MRI measurements of TKE through a phantom stenosis was performed by using clinical 3T MRI scanner. The MRI measurements were verified experimentally by using PIV as the reference standard. In vivo application of MRI-driven TKE was explored in seven patients with aortic valve disease and one healthy volunteer. Transvalvular gradients measured by MRI and echocardiography were compared. Results MRI and PIV measurements of TKE are consistent for turbulent flow (0.666 < R2 < 0.738) with a mean difference of −11.13 J/m3 (SD = 4.34 J/m3). Results of MRI and PIV measurements differ by 2.76 ± 0.82 cm/s (velocity) and −11.13 ± 4.34 J/m3 (TKE) for turbulent flow (Re > 400). The turbulence pressure drop correlates strongly with total TKE (R2 = 0.986). However, in vivo measurements of TKE are not consistent with the transvalvular pressure gradient estimated by echocardiography. Conclusions These results suggest that TKE measurement via MRI may provide a potential benefit as an energy-loss index to characterize blood flow through the aortic valve. However, further clinical studies are necessary to reach definitive conclusions regarding this technique. PMID:26978529

Turbulent Kinetic Energy Measurement Using Phase Contrast MRI for Estimating the Post-Stenotic Pressure Drop: In Vitro Validation and Clinical Application.

PubMed

Ha, Hojin; Kim, Guk Bae; Kweon, Jihoon; Huh, Hyung Kyu; Lee, Sang Joon; Koo, Hyun Jung; Kang, Joon-Won; Lim, Tae-Hwan; Kim, Dae-Hee; Kim, Young-Hak; Kim, Namkug; Yang, Dong Hyun

2016-01-01

Although the measurement of turbulence kinetic energy (TKE) by using magnetic resonance imaging (MRI) has been introduced as an alternative index for quantifying energy loss through the cardiac valve, experimental verification and clinical application of this parameter are still required. The goal of this study is to verify MRI measurements of TKE by using a phantom stenosis with particle image velocimetry (PIV) as the reference standard. In addition, the feasibility of measuring TKE with MRI is explored. MRI measurements of TKE through a phantom stenosis was performed by using clinical 3T MRI scanner. The MRI measurements were verified experimentally by using PIV as the reference standard. In vivo application of MRI-driven TKE was explored in seven patients with aortic valve disease and one healthy volunteer. Transvalvular gradients measured by MRI and echocardiography were compared. MRI and PIV measurements of TKE are consistent for turbulent flow (0.666 < R2 < 0.738) with a mean difference of -11.13 J/m3 (SD = 4.34 J/m3). Results of MRI and PIV measurements differ by 2.76 ± 0.82 cm/s (velocity) and -11.13 ± 4.34 J/m3 (TKE) for turbulent flow (Re > 400). The turbulence pressure drop correlates strongly with total TKE (R2 = 0.986). However, in vivo measurements of TKE are not consistent with the transvalvular pressure gradient estimated by echocardiography. These results suggest that TKE measurement via MRI may provide a potential benefit as an energy-loss index to characterize blood flow through the aortic valve. However, further clinical studies are necessary to reach definitive conclusions regarding this technique.

On the seamless, harmonized use of ISO/IEEE11073 and openEHR.

PubMed

Trigo, Jesús D; Kohl, Christian D; Eguzkiza, Aitor; Martínez-Espronceda, Miguel; Alesanco, Álvaro; Serrano, Luis; García, José; Knaup, Petra

2014-05-01

Standardized exchange of clinical information is a key factor in the provision of high quality health care systems. In this context, the openEHR specification facilitates the management of health data in electronic health records (EHRs), while the ISO/IEEE11073 (also referred to as X73PHD) family of standards provides a reference framework for medical device interoperability. Hospitals and health care providers using openEHR require flawless integration of data coming from external sources, such as X73PHD. Hence, a harmonization process is crucial for achieving a seamless, coherent use of those specifications in real scenarios. Such harmonization is the aim of this paper. Thus, the classes and attributes of a representative number of X73PHD specializations for medical devices--weight, temperature, blood pressure, pulse and heart rate, oximetry, and electrocardiograph--along with the X73PHD core document--ISO/IEEE11073-20601--have been analyzed and mapped to openEHR archetypes. The proposed methodology reuses the existing archetypes when possible and suggests new ones--or appropriate modifications--otherwise. As a result, this paper analyzes the inconsistencies found and the implications thereof in the coordinated use of these two standards. The procedure has also shown how existing standards are able to influence the archetype development process, enhancing the existing archetype corpus.

Improved Measurement of Blood Pressure by Extraction of Characteristic Features from the Cuff Oscillometric Waveform

PubMed Central

Lim, Pooi Khoon; Ng, Siew-Cheok; Jassim, Wissam A.; Redmond, Stephen J.; Zilany, Mohammad; Avolio, Alberto; Lim, Einly; Tan, Maw Pin; Lovell, Nigel H.

2015-01-01

We present a novel approach to improve the estimation of systolic (SBP) and diastolic blood pressure (DBP) from oscillometric waveform data using variable characteristic ratios between SBP and DBP with mean arterial pressure (MAP). This was verified in 25 healthy subjects, aged 28 ± 5 years. The multiple linear regression (MLR) and support vector regression (SVR) models were used to examine the relationship between the SBP and the DBP ratio with ten features extracted from the oscillometric waveform envelope (OWE). An automatic algorithm based on relative changes in the cuff pressure and neighbouring oscillometric pulses was proposed to remove outlier points caused by movement artifacts. Substantial reduction in the mean and standard deviation of the blood pressure estimation errors were obtained upon artifact removal. Using the sequential forward floating selection (SFFS) approach, we were able to achieve a significant reduction in the mean and standard deviation of differences between the estimated SBP values and the reference scoring (MLR: mean ± SD = −0.3 ± 5.8 mmHg; SVR and −0.6 ± 5.4 mmHg) with only two features, i.e., Ratio2 and Area3, as compared to the conventional maximum amplitude algorithm (MAA) method (mean ± SD = −1.6 ± 8.6 mmHg). Comparing the performance of both MLR and SVR models, our results showed that the MLR model was able to achieve comparable performance to that of the SVR model despite its simplicity. PMID:26087370

Computational assessment of model-based wave separation using a database of virtual subjects.

PubMed

Hametner, Bernhard; Schneider, Magdalena; Parragh, Stephanie; Wassertheurer, Siegfried

2017-11-07

The quantification of arterial wave reflection is an important area of interest in arterial pulse wave analysis. It can be achieved by wave separation analysis (WSA) if both the aortic pressure waveform and the aortic flow waveform are known. For better applicability, several mathematical models have been established to estimate aortic flow solely based on pressure waveforms. The aim of this study is to investigate and verify the model-based wave separation of the ARCSolver method on virtual pulse wave measurements. The study is based on an open access virtual database generated via simulations. Seven cardiac and arterial parameters were varied within physiological healthy ranges, leading to a total of 3325 virtual healthy subjects. For assessing the model-based ARCSolver method computationally, this method was used to perform WSA based on the aortic root pressure waveforms of the virtual patients. Asa reference, the values of WSA using both the pressure and flow waveforms provided by the virtual database were taken. The investigated parameters showed a good overall agreement between the model-based method and the reference. Mean differences and standard deviations were -0.05±0.02AU for characteristic impedance, -3.93±1.79mmHg for forward pressure amplitude, 1.37±1.56mmHg for backward pressure amplitude and 12.42±4.88% for reflection magnitude. The results indicate that the mathematical blood flow model of the ARCSolver method is a feasible surrogate for a measured flow waveform and provides a reasonable way to assess arterial wave reflection non-invasively in healthy subjects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Advanced Technical Data Study

DTIC Science & Technology

1975-01-29

will shut down automatically when condenser high pressure causes Pressure Limit Control high pressure switch to release. Press START switch (3...power cable (1) from facility pow- er. Troubleshoot cooling unit, for HI-LOW pressure switch repeated cutout. Refer to AGE ECU Cooling Unit...acti- vate when loss of air flow oc- curred, the pressure switch (3) failed to open circuit. Adjust or replace pressure switch . Refer to

Comparative study of methodologies for pulse wave velocity estimation.

PubMed

Salvi, P; Magnani, E; Valbusa, F; Agnoletti, D; Alecu, C; Joly, L; Benetos, A

2008-10-01

Arterial stiffness, estimated by pulse wave velocity (PWV), is an independent predictor of cardiovascular mortality and morbidity. However, the clinical applicability of these measurements and the elaboration of reference PWV values are difficult due to differences between the various devices used. In a population of 50 subjects aged 20-84 years, we compared PWV measurements with three frequently used devices: the Complior and the PulsePen, both of which determine aortic PWV as the delay between carotid and femoral pressure wave and the PulseTrace, which estimates the Stiffness Index (SI) by analyzing photoplethysmographic waves acquired on the fingertip. PWV was measured twice by each device. Coefficient of variation of PWV was 12.3, 12.4 and 14.5% for PulsePen, Complior and PulseTrace, respectively. These measurements were compared with the reference method, that is, a simultaneous acquisition of pressure waves using two tonometers. High correlation coefficients with the reference method were observed for PulsePen (r = 0.99) and Complior (r = 0.83), whereas for PulseTrace correlation with the reference method was much lower (r = 0.55). Upon Bland-Altman analysis, mean differences of values +/- 2s.d. versus the reference method were -0.15 +/- 0.62 m/s, 2.09 +/- 2.68 m/s and -1.12 +/- 4.92 m/s, for PulsePen, Complior and Pulse-Trace, respectively. This study confirms the reliability of Complior and PulsePen devices in estimating PWV, while the SI determined by the PulseTrace device was found to be inappropriate as a surrogate of PWV. The present results indicate the urgent need for evaluation and comparison of the different devices to standardize PWV measurements and establish reference values.

Evaluation of occupational exposure to infrasonic noise in Poland.

PubMed

Pawlaczyk-Luszczyńska, M

1999-01-01

A short review of infrasound sources and effects on humans is presented. Polish standard PN-86/N-01338 and international standards ISO 7196:1995 and ISO 9612:1997 concerning the measuring techniques of infrasonic noise are described. The results of infrasonic noise measurements performed in the work environment in Poland are discussed. The study concerned the noise emitted by 124 different types of industrial machinery, appliances and means of transport. The measurements were made in typical working conditions with reference to Polish and international standards. The sound pressure levels exceeding Polish admissible values for: (a) workers' health protection were found in 5 (4.0%) cases, (b) ensuring proper conditions for performing basic functions in observational dispatcher cabins etc. in 77 (62.1%) cases; and (c) administration premises, design offices etc. in 92 (74.2%) cases. The admissible sound pressure levels for workers' health protection are in fact the permissible levels for hearing protection, however they do not correspond with the hearing threshold of infrasound the G-weighting characteristic is associated with. The hearing threshold of infrasound (G86 curve) was exceeded in 66.9% of all the industrial machinery and means of transport under study.

Establishing International Blood Pressure References Among Nonoverweight Children and Adolescents Aged 6 to 17 Years.

PubMed

Xi, Bo; Zong, Xin'nan; Kelishadi, Roya; Hong, Young Mi; Khadilkar, Anuradha; Steffen, Lyn M; Nawarycz, Tadeusz; Krzywińska-Wiewiorowska, Małgorzata; Aounallah-Skhiri, Hajer; Bovet, Pascal; Chiolero, Arnaud; Pan, Haiyan; Litwin, Mieczysław; Poh, Bee Koon; Sung, Rita Y T; So, Hung-Kwan; Schwandt, Peter; Haas, Gerda-Maria; Neuhauser, Hannelore K; Marinov, Lachezar; Galcheva, Sonya V; Motlagh, Mohammad Esmaeil; Kim, Hae Soon; Khadilkar, Vaman; Krzyżaniak, Alicja; Romdhane, Habiba Ben; Heshmat, Ramin; Chiplonkar, Shashi; Stawińska-Witoszyńska, Barbara; El Ati, Jalila; Qorbani, Mostafa; Kajale, Neha; Traissac, Pierre; Ostrowska-Nawarycz, Lidia; Ardalan, Gelayol; Parthasarathy, Lavanya; Zhao, Min; Zhang, Tao

2016-01-26

Several distributions of country-specific blood pressure (BP) percentiles by sex, age, and height for children and adolescents have been established worldwide. However, there are no globally unified BP references for defining elevated BP in children and adolescents, which limits international comparisons of the prevalence of pediatric elevated BP. We aimed to establish international BP references for children and adolescents by using 7 nationally representative data sets (China, India, Iran, Korea, Poland, Tunisia, and the United States). Data on BP for 52 636 nonoverweight children and adolescents aged 6 to 19 years were obtained from 7 large nationally representative cross-sectional surveys in China, India, Iran, Korea, Poland, Tunisia, and the United States. BP values were obtained with certified mercury sphygmomanometers in all 7 countries by using standard procedures for BP measurement. Smoothed BP percentiles (50th, 90th, 95th, and 99th) by age and height were estimated by using the Generalized Additive Model for Location Scale and Shape model. BP values were similar between males and females until the age of 13 years and were higher in males than females thereafter. In comparison with the BP levels of the 90th and 95th percentiles of the US Fourth Report at median height, systolic BP of the corresponding percentiles of these international references was lower, whereas diastolic BP was similar. These international BP references will be a useful tool for international comparison of the prevalence of elevated BP in children and adolescents and may help to identify hypertensive youths in diverse populations. © 2015 American Heart Association, Inc.

Establishing International Blood Pressure References Among Non-Overweight Children and Adolescents Aged 6–17 Years

PubMed Central

Xi, Bo; Zong, Xin’nan; Kelishadi, Roya; Hong, Young Mi; Khadilkar, Anuradha; Steffen, Lyn M.; Nawarycz, Tadeusz; Krzywińska-Wiewiorowska, Małgorzata; Aounallah-Skhiri, Hajer; Bovet, Pascal; Chiolero, Arnaud; Pan, Haiyan; Litwin, Mieczysław; Poh, Bee Koon; Sung, Rita Y.T.; So, Hung-Kwan; Schwandt, Peter; Haas, Gerda-Maria; Neuhauser, Hannelore K.; Marinov, Lachezar; Galcheva, Sonya V; Motlagh, Mohammad Esmaeil; Kim, Hae Soon; Khadilkar, Vaman; Krzyżaniak, Alicja; Ben Romdhane, Habiba; Heshmat, Ramin; Chiplonkar, Shashi; Stawińska-Witoszyńska, Barbara; Ati, Jalila El; Qorbani, Mostafa; Kajale, Neha; Traissac, Pierre; Ostrowska-Nawarycz, Lidia; Ardalan, Gelayol; Parthasarathy, Lavanya; Zhao, Min; Zhang, Tao

2015-01-01

Background Several distributions of country-specific blood pressure (BP) percentiles by sex, age and height for children and adolescents have been established worldwide. However, there are no globally unified BP references for defining elevated BP in children and adolescents, which limit international comparisons of prevalence of pediatric elevated BP. We aimed to establish international BP references for children and adolescents using seven nationally representative data (China, India, Iran, Korea, Poland, Tunisia and USA). Methods and Results Data on BP for 52,636 non-overweight children and adolescents aged 6–19 years were obtained from seven large nationally representative cross-sectional surveys in China, India, Iran, Korea, Poland, Tunisia, and USA. BP values were obtained with certified mercury sphygmomanometers in all seven countries, using standard procedures for BP measurement. Smoothed BP percentiles (50th, 90th, 95th and 99th) by age and height were estimated using the Generalized Additive Model for Location Scale and Shape (GAMLSS) model. BP values were similar between males and females until the age of 13 years and were higher in males than females thereafter. Compared to BP level of the 90th and 95th percentiles of the U.S. Fourth Report at median height, systolic BP of the corresponding percentiles of these international references was lower while diastolic BP was similar. Conclusions These international BP references will be a useful tool for international comparison of the prevalence of elevated BP in children and adolescents and may help identify hypertensive youths in diverse populations. PMID:26671979

Explosive materials equivalency, test methods and evaluation

NASA Technical Reports Server (NTRS)

Koger, D. M.; Mcintyre, F. L.

1980-01-01

Attention is given to concepts of explosive equivalency of energetic materials based on specific airblast parameters. A description is provided of a wide bandwidth high accuracy instrumentation system which has been used extensively in obtaining pressure time profiles of energetic materials. The object of the considered test method is to determine the maximum output from the detonation of explosive materials in terms of airblast overpressure and positive impulse. The measured pressure and impulse values are compared with known characteristics of hemispherical TNT data to determine the equivalency of the test material in relation to TNT. An investigation shows that meaningful comparisons between various explosives and a standard reference material such as TNT should be based upon the same parameters. The tests should be conducted under the same conditions.

Application of the control volume mixed finite element method to a triangular discretization

USGS Publications Warehouse

Naff, R.L.

2012-01-01

A two-dimensional control volume mixed finite element method is applied to the elliptic equation. Discretization of the computational domain is based in triangular elements. Shape functions and test functions are formulated on the basis of an equilateral reference triangle with unit edges. A pressure support based on the linear interpolation of elemental edge pressures is used in this formulation. Comparisons are made between results from the standard mixed finite element method and this control volume mixed finite element method. Published 2011. This article is a US Government work and is in the public domain in the USA. ?? 2012 John Wiley & Sons, Ltd. This article is a US Government work and is in the public domain in the USA.

40 CFR 60.485a - Test methods and procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 0.3 kPa at 20 °C (1.2 in. H2O at 68 °F). Standard reference texts or ASTM D2879-83, 96, or 97... concentration of the pure organic components having a vapor pressure greater than 0.3 kPa at 20 °C (1.2 in. H2O... Hi = net heat of combustion of sample component “i” at 25 °C and 760 mm Hg (77 °F and 14.7 psi), kcal...

40 CFR 60.485a - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 0.3 kPa at 20 °C (1.2 in. H2O at 68 °F). Standard reference texts or ASTM D2879-83, 96, or 97... concentration of the pure organic components having a vapor pressure greater than 0.3 kPa at 20 °C (1.2 in. H2O...,” ppm Hi = net heat of combustion of sample component “i” at 25 °C and 760 mm Hg (77 °F and 14.7 psi...

40 CFR 60.485a - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 0.3 kPa at 20 °C (1.2 in. H2O at 68 °F). Standard reference texts or ASTM D2879-83, 96, or 97... concentration of the pure organic components having a vapor pressure greater than 0.3 kPa at 20 °C (1.2 in. H2O... Hi = net heat of combustion of sample component “i” at 25 °C and 760 mm Hg (77 °F and 14.7 psi), kcal...

40 CFR 60.485a - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 0.3 kPa at 20 °C (1.2 in. H2O at 68 °F). Standard reference texts or ASTM D2879-83, 96, or 97... concentration of the pure organic components having a vapor pressure greater than 0.3 kPa at 20 °C (1.2 in. H2O...,” ppm Hi = net heat of combustion of sample component “i” at 25 °C and 760 mm Hg (77 °F and 14.7 psi...

40 CFR 60.485a - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 0.3 kPa at 20 °C (1.2 in. H2O at 68 °F). Standard reference texts or ASTM D2879-83, 96, or 97... concentration of the pure organic components having a vapor pressure greater than 0.3 kPa at 20 °C (1.2 in. H2O...,” ppm Hi = net heat of combustion of sample component “i” at 25 °C and 760 mm Hg (77 °F and 14.7 psi...

Earth Global Reference Atmospheric Model (Earth-GRAM) GRAM Virtual Meeting

NASA Technical Reports Server (NTRS)

White, Patrick

2017-01-01

What is Earth-GRAM? Provide monthly mean and standard deviation for any point in atmosphere; Monthly, Geographic, and Altitude Variation. Earth-GRAM is a C++ software package; Currently distributed as Earth-GRAM 2016. Atmospheric variables included: pressure, density, temperature, horizontal and vertical winds, speed of sound, and atmospheric constituents. Used by engineering community because of ability to create dispersions inatmosphere at a rapid runtime; Often embedded in trajectory simulation software. Not a forecast model. Does not readily capture localized atmospheric effects.

Carbureting conditions characteristics of aircraft engines

NASA Technical Reports Server (NTRS)

Tice, Percival S

1920-01-01

Tests were conducted at the altitude laboratory erected at the Bureau of Standards for the National Advisory Committee for Aeronautics to determine the changes in engine performance with changes in atmospheric temperature and pressure at various levels above the earth's surface, with special reference to (a) the variables affecting the functioning of the carburetor and (b) the changes in performance resulting from variables in the carburetor itself. This report constitutes a concise statement of the difficulties to be encountered in this branch of carburetion.

Which cuff should I use? Indirect blood pressure measurement for the diagnosis of hypertension in patients with obesity: a diagnostic accuracy review.

PubMed

Irving, Greg; Holden, John; Stevens, Richard; McManus, Richard J

2016-11-03

To determine the diagnostic accuracy of different methods of blood pressure (BP) measurement compared with reference standards for the diagnosis of hypertension in patients with obesity with a large arm circumference. Systematic review with meta-analysis with hierarchical summary receiver operating characteristic models. Bland-Altman analyses where individual patient data were available. Methodological quality appraised using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS2) criteria. MEDLINE, EMBASE, Cochrane, DARE, Medion and Trip databases were searched. Cross-sectional, randomised and cohort studies of diagnostic test accuracy that compared any non-invasive BP tests (upper arm, forearm, wrist, finger) with an appropriate reference standard (invasive BP, correctly fitting upper arm cuff, ambulatory BP monitoring) in primary care were included. 4037 potentially relevant papers were identified. 20 studies involving 26 different comparisons met the inclusion criteria. Individual patient data were available from 4 studies. No studies satisfied all QUADAS2 criteria. Compared with the reference test of invasive BP, a correctly fitting upper arm BP cuff had a sensitivity of 0.87 (0.79 to 0.93) and a specificity of 0.85 (0.64 to 0.95); insufficient evidence was available for other comparisons to invasive BP. Compared with the reference test of a correctly fitting upper arm cuff, BP measurement at the wrist had a sensitivity of 0.92 (0.64 to 0.99) and a specificity of 0.92 (0.85 to 0.87). Measurement with an incorrectly fitting standard cuff had a sensitivity of 0.73 (0.67 to 0.78) and a specificity of 0.76 (0.69 to 0.82). Measurement at the forearm had a sensitivity of 0.84 (0.71 to 0.92) and a specificity 0.75 of (0.66 to 0.83). Bland-Altman analysis of individual patient data from 3 studies comparing wrist and upper arm BP showed a mean difference of 0.46 mm Hg for systolic BP measurement and 2.2 mm Hg for diastolic BP measurement. BP measurement with a correctly fitting upper arm cuff is sufficiently sensitive and specific to diagnose hypertension in patients with obesity with a large upper arm circumference. If a correctly fitting upper arm cuff cannot be applied, an incorrectly fitting standard size cuff should not be used and BP measurement at the wrist should be considered. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Which cuff should I use? Indirect blood pressure measurement for the diagnosis of hypertension in patients with obesity: a diagnostic accuracy review

PubMed Central

Holden, John

2016-01-01

Objective To determine the diagnostic accuracy of different methods of blood pressure (BP) measurement compared with reference standards for the diagnosis of hypertension in patients with obesity with a large arm circumference. Design Systematic review with meta-analysis with hierarchical summary receiver operating characteristic models. Bland-Altman analyses where individual patient data were available. Methodological quality appraised using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS2) criteria. Data sources MEDLINE, EMBASE, Cochrane, DARE, Medion and Trip databases were searched. Eligibility criteria Cross-sectional, randomised and cohort studies of diagnostic test accuracy that compared any non-invasive BP tests (upper arm, forearm, wrist, finger) with an appropriate reference standard (invasive BP, correctly fitting upper arm cuff, ambulatory BP monitoring) in primary care were included. Results 4037 potentially relevant papers were identified. 20 studies involving 26 different comparisons met the inclusion criteria. Individual patient data were available from 4 studies. No studies satisfied all QUADAS2 criteria. Compared with the reference test of invasive BP, a correctly fitting upper arm BP cuff had a sensitivity of 0.87 (0.79 to 0.93) and a specificity of 0.85 (0.64 to 0.95); insufficient evidence was available for other comparisons to invasive BP. Compared with the reference test of a correctly fitting upper arm cuff, BP measurement at the wrist had a sensitivity of 0.92 (0.64 to 0.99) and a specificity of 0.92 (0.85 to 0.87). Measurement with an incorrectly fitting standard cuff had a sensitivity of 0.73 (0.67 to 0.78) and a specificity of 0.76 (0.69 to 0.82). Measurement at the forearm had a sensitivity of 0.84 (0.71 to 0.92) and a specificity 0.75 of (0.66 to 0.83). Bland-Altman analysis of individual patient data from 3 studies comparing wrist and upper arm BP showed a mean difference of 0.46 mm Hg for systolic BP measurement and 2.2 mm Hg for diastolic BP measurement. Conclusions BP measurement with a correctly fitting upper arm cuff is sufficiently sensitive and specific to diagnose hypertension in patients with obesity with a large upper arm circumference. If a correctly fitting upper arm cuff cannot be applied, an incorrectly fitting standard size cuff should not be used and BP measurement at the wrist should be considered. PMID:27810973

Bilateral comparison of 10 V standards between the NSAI-NML (Ireland) and the BIPM, January to February 2013 (part of the ongoing BIPM key comparison BIPM.EM-K11.b)

NASA Astrophysics Data System (ADS)

Power, O.; Chayramy, R.; Solve, S.; Stock, M.

2014-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out from January to February 2013. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_8 (Z8) and BIPM_9 (Z9), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (electromotive force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the value assigned to DC voltage standard by NSAI-NML, at the level of 10 V, at NSAI-NML, UNML, and that assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 5 February 2013. UNML - UBIPM = -0.63 µV uc = 1.31 µV, at 10 V where uc is thecombined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML,based on KJ-90, and the uncertainty related to the comparison. The comparison results show that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated standard uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral Comparison of 1 V and 10 V Standards between the NIS (Egypt) and the BIPM, August to September 2014 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Stock, M.; Abdel Mageed, Hala M.; Aladdin, Omar M.; Raouf, M. Helmy A.

2015-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the National Institute for Standards (NIS), Giza, Egypt, was carried out from August to September 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPMB (ZB) and BIPMC (ZC), were transported as hand luggage on board an airplane to NIS and back to BIPM. At NIS, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at NIS, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by NIS, at the level of 1.018 V and 10 V, at NIS, UNIS, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 7 September 2014. UNIS - UBIPM = 0.09 µV uc = 0.08 µV, at 1 V UNIS - UBIPM = 0.22 µV uc = 0.14 µV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NIS, based on KJ-90, and the uncertainty related to the comparison. This is a satisfactory result. The comparison result shows that the voltage standards maintained by NIS and the BIPM were equivalent, within their stated standard uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 10 V standards between the NSAI-NML (Ireland) and the BIPM, March 2014 (part of the ongoing BIPM key comparison BIPM.EM-K11.b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Power, O.; Stock, M.

2014-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out in February and March 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_4 (Z4) and BIPM_5 (Z5), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the value assigned to DC voltage standard by NSAI-NML, at the level of 10 V, at NSAI-NML, UNML, and that assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 10 March 2014. UNML - UBIPM = -0.64 µV uc = 1.35 µV, at 10 V where uc is thecombined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML,based on KJ-90, and the uncertainty related to the comparison. The comparison results show that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated standard uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Multi-class, multi-residue analysis of pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers and novel flame retardants in fish using fast, low-pressure gas chromatography-tandem mass spectrometry.

PubMed

Sapozhnikova, Yelena; Lehotay, Steven J

2013-01-03

A multi-class, multi-residue method for the analysis of 13 novel flame retardants, 18 representative pesticides, 14 polychlorinated biphenyl (PCB) congeners, 16 polycyclic aromatic hydrocarbons (PAHs), and 7 polybrominated diphenyl ether (PBDE) congeners in catfish muscle was developed and evaluated using fast low pressure gas chromatography triple quadrupole tandem mass spectrometry (LP-GC/MS-MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with acetonitrile and dispersive solid-phase extraction (d-SPE) clean-up with zirconium-based sorbent prior to LP-GC/MS-MS analysis. The developed method was evaluated at 4 spiking levels and further validated by analysis of NIST Standard Reference Materials (SRMs) 1974B and 1947. Sample preparation for a batch of 10 homogenized samples took about 1h/analyst, and LP-GC/MS-MS analysis provided fast separation of multiple analytes within 9min achieving high throughput. With the use of isotopically labeled internal standards, recoveries of all but one analyte were between 70 and 120% with relative standard deviations less than 20% (n=5). The measured values for both SRMs agreed with certified/reference values (72-119% accuracy) for the majority of analytes. The detection limits were 0.1-0.5ng g(-1) for PCBs, 0.5-10ng g(-1) for PBDEs, 0.5-5ng g(-1) for select pesticides and PAHs and 1-10ng g(-1) for flame retardants. The developed method was successfully applied for analysis of catfish samples from the market. Published by Elsevier B.V.

Effect of spray application technique on spray deposition in greenhouse strawberries and tomatoes.

PubMed

Braekman, Pascal; Foque, Dieter; Messens, Winy; Van Labeke, Marie-Christine; Pieters, Jan G; Nuyttens, David

2010-02-01

Increasingly, Flemish greenhouse growers are using spray booms instead of spray guns to apply plant protection products. Although the advantages of spray booms are well known, growers still have many questions concerning nozzle choice and settings. Spray deposition using a vertical spray boom in tomatoes and strawberries was compared with reference spray equipment. Five different settings of nozzle type, size and pressure were tested with the spray boom. In general, the standard vertical spray boom performed better than the reference spray equipment in strawberries (spray gun) and in tomatoes (air-assisted sprayer). Nozzle type and settings significantly affected spray deposition and crop penetration. Highest overall deposits in strawberries were achieved using air-inclusion or extended-range nozzles. In tomatoes, the extended-range nozzles and the twin air-inclusion nozzles performed best. Using smaller-size extended-range nozzles above the recommended pressure range resulted in lower deposits, especially inside the crop canopy. The use of a vertical spray boom is a promising technique for applying plant protection products in a safe and efficient way in tomatoes and strawberries, and nozzle choice and setting should be carefully considered.

Fluid relief and check valve

DOEpatents

Blaedel, K.L.; Lord, S.C.; Murray, I.

1986-07-17

A passive fluid pressure relief and check valve allows the relief pressure to be slaved to a reference pressure independently of the exhaust pressure. The pressure relief valve is embodied by a submerged vent line in a sealing fluid, the relief pressure being a function of the submerged depth. A check valve is embodied by a vertical column of fluid (the maximum back pressure being a function of the height of the column of fluid). The pressure is vented into an exhaust system which keeps the exhaust out of the area providing the reference pressure.

Vadose zone isobaric well

DOEpatents

Hubbell, Joel M.; Sisson, James B.

2001-01-01

A deep tensiometer is configured with an outer guide tube having a vented interval along a perforate section at its lower end, which is isolated from atmospheric pressure at or above grade. A transducer having a monitoring port and a reference port is located within a coaxial inner guide tube. The reference port of the transducer is open to the vented interval of the outer guide tube, which has the same gas pressure as in the sediment surrounding the tensiometer. The reference side of the pressure transducer is thus isolated from the effects of atmospheric pressure changes and relative to pressure changes in the material surrounding the tensiometer measurement location and so it is automatically compensated for such pressure changes.

Final report on EURAMET.QM-S6/1195: Bilateral comparison of liquefied hydrocarbon mixtures in constant pressure (piston) cylinders

NASA Astrophysics Data System (ADS)

Brown, Andrew S.; Downey, Michael L.; Milton, Martin J. T.; van der Veen, Adriaan M. H.; Zalewska, Ewelina T.; Li, Jianrong

2013-01-01

Traceable liquid hydrocarbon mixtures are required in order to underpin measurements of the composition and other physical properties of LPG (liquefied petroleum gas) and LNG (liquefied natural gas), thus meeting the needs of an increasingly large European industrial market. The development of traceable liquid hydrocarbon standards by National Measurement Institutes (NMIs) was still at a relatively early stage at the time this comparison was proposed in 2011. NPL and VSL, who were the only NMIs active in this area, had developed methods for the preparation and analysis of such standards in constant pressure (piston) cylinders, but neither laboratory had Calibration and Measurement Capabilities (CMCs) for these mixtures. This report presents the results of EURAMET 1195, the first comparison of liquid hydrocarbon mixtures between NMIs, which assessed the preparation and analytical capabilities of NPL and VSL for these mixtures. The comparison operated between August 2011 and January 2012. Each laboratory prepared a liquid hydrocarbon standard with nominally the same composition and these standards were exchanged for analysis. The results of the comparison show a good agreement between the laboratories' results and the comparison reference values for the six components with amount fractions greater than 1.0 cmol/mol (propane, propene, iso-butene, n-butane, iso-butane and 1-butene). Measurement of the three components with lower amount fractions (1,3-butadiene, iso-pentane and n-pentane) proved more challenging. In all but one case, the differences from the comparison reference values for these three components were greater than the expanded measurement uncertainty. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Static ankle joint equinus: toward a standard definition and diagnosis.

PubMed

Charles, James; Scutter, Sheila D; Buckley, Jonathan

2010-01-01

Equinus is characterized by reduced dorsiflexion of the ankle joint, but there is a lack of consensus regarding criteria for definition and diagnosis. This review examines the literature relating to the definition, assessment, diagnosis, prevalence, and complications of equinus. Articles on equinus and assessment of ankle joint range of motion were identified by searching the EMBASE, Medline, PubMed, EBSCOhost, Cinahl, and Cochrane databases and by examining the reference lists of the articles found. There is inconsistency regarding the magnitude of reduction in dorsiflexion required to constitute a diagnosis of equinus and no standard method for assessment; hence, the prevalence of equinus is unknown. Goniometric assessment of ankle joint range of motion was shown to be unreliable, whereas purpose-built tools demonstrated good reliability. Reduced dorsiflexion is associated with alterations in gait, increased forefoot pressure, and ankle injury, the magnitude of reduction in range of motion required to predispose to foot or lower-limb abnormalities is not known. In the absence of definitive data, we propose a two-stage definition of equinus: the first stage would reflect dorsiflexion of less than 10 degrees with minor compensation and a minor increase in forefoot pressure, and the second stage would reflect dorsiflexion of less than 5 degrees with major compensation and a major increase in forefoot pressure. This proposed definition of equinus will assist with standardizing the diagnosis and will provide a basis for future studies of the prevalence, causes, and complications of this condition.

Chemical thermodynamic data. 1. The concept of links to the chemical elements and the historical development of key thermodynamic data

NASA Astrophysics Data System (ADS)

Wolery, Thomas J.; Jové Colón, Carlos F.

2017-09-01

Chemical thermodynamic data remain a keystone for geochemical modeling and reactive transport simulation as applied to an increasing number of applications in the earth sciences, as well as applications in other areas including metallurgy, material science, and industrial process design. The last century has seen the development of a large body of thermodynamic data and a number of major compilations. The past several decades have seen the development of thermodynamic databases in digital form designed to support computer calculations. However, problems with thermodynamic data appear to be persistent. One problem pertains to the use of inconsistent primary key reference data. Such data pertain to elemental reference forms and key, stoichiometrically simple chemical species including metal oxides, CO2, water, and aqueous species such as Na+ and Cl-. A consistent set of primary key data (standard Gibbs energies, standard enthalpies, and standard entropies for key chemical species) for 298.15 K and 1 bar pressure is essential. Thermochemical convention is to define the standard Gibbs energy and the standard enthalpy of an individual chemical species in terms of formation from reference forms of the constituent chemical elements. We propose a formal concept of "links" to the elemental reference forms. This concept involves a documented understanding of all reactions and calculations leading to values for a formation property (standard Gibbs energy or enthalpy). A valid link consists of two parts: (a) the path of reactions and corrections and (b) the associated data, which are key data. Such a link differs from a bare "key" or "reference" datum in that it requires additional information. Some or all of its associated data may also be key data. In evaluating a reported thermodynamic datum, one should identify the links to the chemical elements, a process which can be time-consuming and which may lead to a dead end (an incomplete link). The use of two or more inconsistent links to the same elemental reference form in a thermodynamic database will result in an inconsistency in the database. Thus, in constructing a database, it is important to establish a set of reliable links (generally resulting in a set of primary reference data) and then correct all data adopted subsequently for consistency with that set. Recommended values of key data have not been constant through history. We review some of this history through the lens of major compilations and other influential reports, and note a number of problem areas. Finally, we illustrate the concepts developed in this paper by applying them to some key species of geochemical interest, including liquid water; quartz and aqueous silica; and gibbsite, corundum, and the aqueous aluminum ion.

Repositioning for pressure ulcer prevention in adults.

PubMed

Gillespie, Brigid M; Chaboyer, Wendy P; McInnes, Elizabeth; Kent, Bridie; Whitty, Jennifer A; Thalib, Lukman

2014-04-03

A pressure ulcer (PU), also referred to as a 'pressure injury', 'pressure sore', or 'bedsore' is defined as an area of localised tissue damage that is caused by unrelieved pressure, friction or shearing forces on any part of the body. PUs commonly occur in patients who are elderly and less mobile, and carry significant human and economic impacts. Immobility and physical inactivity are considered to be major risk factors for PU development and the manual repositioning of patients in hospital or long-term care is a common pressure ulcer prevention strategy. The objectives of this review were to:1) assess the effects of repositioning on the prevention of PUs in adults, regardless of risk or in-patient setting;2) ascertain the most effective repositioning schedules for preventing PUs in adults; and3) ascertain the incremental resource consequences and costs associated with implementing different repositioning regimens compared with alternate schedules or standard practice. We searched the following electronic databases to identify reports of the relevant randomised controlled trials: the Cochrane Wounds Group Specialised Register (searched 06 September 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 8); Ovid MEDLINE (1948 to August, Week 4, 2013); Ovid EMBASE (1974 to 2013, Week 35); EBESCO CINAHL (1982 to 30 August 2013); and the reference sections of studies that were included in the review. Randomised controlled trials (RCTs), published or unpublished, that assessed the effects of any repositioning schedule or different patient positions and measured PU incidence in adults in any setting. Two review authors independently performed study selection, risk of bias assessment and data extraction. We included three RCTs and one economic study representing a total of 502 randomised participants from acute and long-term care settings. Two trials compared the 30º and 90º tilt positions using similar repositioning frequencies (there was a small difference in frequency of overnight repositioning in the 90º tilt groups between the trials). The third RCT compared alternative repositioning frequencies.All three studies reported the proportion of patients developing PU of any grade, stage or category. None of the trials reported on pain, or quality of life, and only one reported on cost. All three trials were at high risk of bias.The two trials of 30º tilt vs. 90º were pooled using a random effects model (I² = 69%) (252 participants). The risk ratio for developing a PU in the 30º tilt and the standard 90º position was very imprecise (pooled RR 0.62, 95% CI 0.10 to 3.97, P=0.62, very low quality evidence). This comparison is underpowered and at risk of a Type 2 error (only 21 events).In the third study, a cluster randomised trial, participants were randomised between 2-hourly and 3-hourly repositioning on standard hospital mattresses and 4 hourly and 6 hourly repositioning on viscoelastic foam mattresses. This study was also underpowered and at high risk of bias. The risk ratio for pressure ulcers (any category) with 2-hourly repositioning compared with 3-hourly repositioning on a standard mattress was imprecise (RR 0.90, 95% CI 0.69 to 1.16, very low quality evidence). The risk ratio for pressure ulcers (any category) was compatible with a large reduction and no difference between 4-hourly repositioning and 6-hourly repositioning on viscoelastic foam (RR 0.73, 95% CI 0.53 to 1.02, very low quality evidence).A cost-effectiveness analysis based on data derived from one of the included parallel RCTs compared 3-hourly repositioning using the 30º tilt overnight with standard care consisting of 6-hourly repositioning using the 90º lateral rotation overnight. In this evaluation the only included cost was nursing time. The intervention was reported to be cost saving compared with standard care (nurse time cost per patient €206.6 vs €253.1, incremental difference €-46.5; 95%CI: €-1.25 to €-74.60). Repositioning is an integral component of pressure ulcer prevention and treatment; it has a sound theoretical rationale, and is widely recommended and used in practice. The lack of robust evaluations of repositioning frequency and position for pressure ulcer prevention mean that great uncertainty remains but it does not mean these interventions are ineffective since all comparisons are grossly underpowered. Current evidence is small in volume and at risk of bias and there is currently no strong evidence of a reduction in pressure ulcers with the 30° tilt compared with the standard 90º position or good evidence of an effect of repositioning frequency. There is a clear need for high-quality, adequately-powered trials to assess the effects of position and optimal frequency of repositioning on pressure ulcer incidence.The limited data derived from one economic evaluation means it remains unclear whether repositioning every 3 hours using the 30º tilt is less costly in terms of nursing time and more effective than standard care involving repositioning every 6 hours using a 90º tilt.

Bilateral comparison of 1 V and 10 V standards between the INM (Romania) and the BIPM, August to October 2013 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Stock, M.; Simionescu, M.; Cîrneanu, L.

2014-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Institut National de Metrologie (INM), Bucharest, Romania, was carried out from August to October 2013. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_7 (Z7) and BIPM_8 (Z8), were transported by freight to INM. At INM, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (electromotive force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at INM, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by INM, at the level of 1.018 V and 10 V, at INM, UINM, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 6 September 2013. UINM - UBIPM = -0.014 µV uc = 0.051 µV, at 1 V UINM - UBIPM = -0.43 µV uc = 0.34 µV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at INM, based on KJ-90, and the uncertainty related to the comparison. These are satisfactory results. The comparison results show that the voltage standards maintained by INM and the BIPM were equivalent, within the comparison uncertainty, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Development, characterization, and validation of an optical transfer standard for ammonia in air

NASA Astrophysics Data System (ADS)

Lüttschwager, Nils; Balslev-Harder, David; Leuenberger, Daiana; Pogány, Andrea; Werhahn, Olav; Ebert, Volker

2017-04-01

Ammonia is an atmospheric trace gas that is predominantly emitted from anthropogenic agricultural activities. Since elevated levels of ammonia can have negative effects to human health as well as ecosystems, it is imperative to monitor and control ammonia emissions. This requires SI-traceable standards to calibrate ammonia monitoring instrumentation and to make measurements comparable. The lack of such standards became a pressing issue in recent years and the MetNH3 project (www.metnh3.eu) was initiated to fill the gap, pursuing different strategies. The work that we present was part of these endeavours and focusses on the development and application of an optical transfer standard for amount fraction measurements of ammonia in ambient air. An optical transfer standard (OTS) offers an alternative to calibrations of air monitoring instrumentation by means of reference gas mixtures. With an OTS, absolute amount fraction results are derived by evaluating absorption spectra using a spectral model and pre-measured spectral properties of the analyte. In that way, the instrument can measure calibration gas-independent ("calibration-free") and, moreover, can itself serve as standard to calibrate air monitoring analyzers. Molecular spectral properties are the excellent, non-drifting point of reference of the OTS and form, together with traceable measurements of temperature and pressure, the basis for SI-traceable amount fraction measurements. We developed an OTS based on a commercial cavity-ring-down spectrometer with a detection limit below 1 ppb (1 nmol/mol). A custom spectral data evaluation routine for absolute, calibration-free measurements, as well as measurements of spectral properties of ammonia with the focus on measurement uncertainty and traceability [1] are the fundaments of our OTS. Validation measurements were conducted using a SI-traceable ammonia reference gas generator over a period of several months. Here, we present an evaluation of the performance of our OTS from 1 ppb to 200 ppb. We found the results obtained with the OTS to be concordant to reference gas mixtures yielding amount fraction results with standard uncertainties of less than 3 %, for which an uncertainty budget is provided. Acknowledgement: This work was supported by the European Metrology Research Programme (EMRP). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. References 1. A. Pogány, O. Werhahn, and V. Ebert, High-Accuracy Ammonia Line Intensity Measurements at 1.5 µm, in Imaging and Applied Optics 2016, OSA Technical Digest (online) (Optical Society of America, 2016), paper JT3A.15, DOI: 10.1364/3D.2016.JT3A.15

Cardiometabolic risk assessments by body mass index z-score or waist-to-height ratio in a multiethnic sample of sixth-graders.

PubMed

Kahn, Henry S; El ghormli, Laure; Jago, Russell; Foster, Gary D; McMurray, Robert G; Buse, John B; Stadler, Diane D; Treviño, Roberto P; Baranowski, Tom

2014-01-01

Convention defines pediatric adiposity by the body mass index z-score (BMIz) referenced to normative growth charts. Waist-to-height ratio (WHtR) does not depend on sex-and-age references. In the HEALTHY Study enrollment sample, we compared BMIz with WHtR for ability to identify adverse cardiometabolic risk. Among 5,482 sixth-grade students from 42 middle schools, we estimated explanatory variations (R (2)) and standardized beta coefficients of BMIz or WHtR for cardiometabolic risk factors: insulin resistance (HOMA-IR), lipids, blood pressures, and glucose. For each risk outcome variable, we prepared adjusted regression models for four subpopulations stratified by sex and high versus lower fatness. For HOMA-IR, R (2) attributed to BMIz or WHtR was 19%-28% among high-fatness and 8%-13% among lower-fatness students. R (2) for lipid variables was 4%-9% among high-fatness and 2%-7% among lower-fatness students. In the lower-fatness subpopulations, the standardized coefficients for total cholesterol/HDL cholesterol and triglycerides tended to be weaker for BMIz (0.13-0.20) than for WHtR (0.17-0.28). Among high-fatness students, BMIz and WHtR correlated with blood pressures for Hispanics and whites, but not black boys (systolic) or girls (systolic and diastolic). In 11-12 year olds, assessments by WHtR can provide cardiometabolic risk estimates similar to conventional BMIz without requiring reference to a normative growth chart.

Postanesthesia patients with large upper arm circumference: is use of an "extra-long" adult cuff or forearm cuff placement accurate?

PubMed

Watson, Sheri; Aguas, Marita; Bienapfl, Tracy; Colegrove, Pat; Foisy, Nancy; Jondahl, Bonnie; Yosses, Mary Beth; Yu, Larissa; Anastas, Zoe

2011-06-01

The purpose of this study was to determine if blood pressure (BP) measured in the forearm or with an extra-long BP cuff in the upper arm accurately reflects BP measured in the upper arm with an appropriately sized BP cuff in patients with large upper arm circumference. A method-comparison design was used with a convenience sample of 49 PACU patients. Noninvasive blood pressures were obtained in two different locations (forearm; upper arm) and in the upper arm with an extra-long adult and recommended large adult cuff sizes. Data were analyzed by calculating bias and precision for the BP cuff size and location and Student's t-tests, with P < .0125 considered significant. Significantly higher forearm systolic (P < .0001) and diastolic (P < .0002) BP measurements were found compared to BP obtained in the upper arm with the reference standard BP cuff. Significantly higher systolic (t(48df) = 5.38, P < .0001), but not diastolic (t(48df) = 4.11, P < .019), BP differences were found for BP measured with the extra-long cuff at the upper arm site compared to the upper arm, reference standard BP. Findings suggest that the clinical practice of using the forearm or an extra-long cuff in the upper arm for BP measurement in post anesthesia patients with large upper arm circumferences may result in inaccurate BP values. Copyright © 2011 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Active fluids at circular boundaries: swim pressure and anomalous droplet ripening.

PubMed

Jamali, Tayeb; Naji, Ali

2018-06-13

We investigate the swim pressure exerted by non-chiral and chiral active particles on convex or concave circular boundaries. Active particles are modeled as non-interacting and non-aligning self-propelled Brownian particles. The convex and concave circular boundaries are used to model a fixed inclusion immersed in an active bath and a cavity (or container) enclosing the active particles, respectively. We first present a detailed analysis of the role of convex versus concave boundary curvature and of the chirality of active particles in their spatial distribution, chirality-induced currents, and the swim pressure they exert on the bounding surfaces. The results will then be used to predict the mechanical equilibria of suspended fluid enclosures (generically referred to as 'droplets') in a bulk with active particles being present either inside the bulk fluid or within the suspended droplets. We show that, while droplets containing active particles behave in accordance with standard capillary paradigms when suspended in a normal bulk, those containing a normal fluid exhibit anomalous behaviors when suspended in an active bulk. In the latter case, the excess swim pressure results in non-monotonic dependence of the inside droplet pressure on the droplet radius; hence, revealing an anomalous regime of behavior beyond a threshold radius, in which the inside droplet pressure increases upon increasing the droplet size. Furthermore, for two interconnected droplets, mechanical equilibrium can occur also when the droplets have different sizes. We thus identify a regime of anomalous droplet ripening, where two unequal-sized droplets can reach a final state of equal size upon interconnection, in stark contrast with the standard Ostwald ripening phenomenon, implying shrinkage of the smaller droplet in favor of the larger one.

rpSPH: a novel smoothed particle hydrodynamics algorithm

NASA Astrophysics Data System (ADS)

Abel, Tom

2011-05-01

We suggest a novel discretization of the momentum equation for smoothed particle hydrodynamics (SPH) and show that it significantly improves the accuracy of the obtained solutions. Our new formulation which we refer to as relative pressure SPH, rpSPH, evaluates the pressure force with respect to the local pressure. It respects Newton's first law of motion and applies forces to particles only when there is a net force acting upon them. This is in contrast to standard SPH which explicitly uses Newton's third law of motion continuously applying equal but opposite forces between particles. rpSPH does not show the unphysical particle noise, the clumping or banding instability, unphysical surface tension and unphysical scattering of different mass particles found for standard SPH. At the same time, it uses fewer computational operations and only changes a single line in existing SPH codes. We demonstrate its performance on isobaric uniform density distributions, uniform density shearing flows, the Kelvin-Helmholtz and Rayleigh-Taylor instabilities, the Sod shock tube, the Sedov-Taylor blast wave and a cosmological integration of the Santa Barbara galaxy cluster formation test. rpSPH is an improvement in these cases. The improvements come at the cost of giving up exact momentum conservation of the scheme. Consequently, one can also obtain unphysical solutions particularly at low resolutions.

A pilot randomised controlled trial of negative pressure wound therapy to treat grade III/IV pressure ulcers [ISRCTN69032034

PubMed Central

2012-01-01

Background Negative pressure wound therapy (NPWT) is widely promoted as a treatment for full thickness wounds; however, there is a lack of high-quality research evidence regarding its clinical and cost effectiveness. A trial of NPWT for the treatment of grade III/IV pressure ulcers would be worthwhile but premature without assessing whether such a trial is feasible. The aim of this pilot randomised controlled trial was to assess the feasibility of conducting a future full trial of NPWT for the treatment of grade III and IV pressure ulcers and to pilot all aspects of the trial. Methods This was a two-centre (acute and community), pilot randomised controlled trial. Eligible participants were randomised to receive either NPWT or standard care (SC) (spun hydrocolloid, alginate or foam dressings). Outcome measures were time to healing of the reference pressure ulcer, recruitment rates, frequency of treatment visits, resources used and duration of follow-up. Results Three hundred and twelve patients were screened for eligibility into this trial over a 12-month recruitment period and 12/312 participants (3.8%) were randomised: 6 to NPWT and 6 to SC. Only one reference pressure ulcer healed (NPWT group) during follow-up (time to healing 79 days). The mean number of treatment visits per week was 3.1 (NPWT) and 5.7 (SC); 6/6 NPWT and 1/6 SC participants withdrew from their allocated trial treatment. The mean duration of follow-up was 3.8 (NPWT) and 5.0 (SC) months. Conclusions This pilot trial yielded vital information for the planning of a future full study including projected recruitment rate, required duration of follow-up and extent of research nurse support required. Data were also used to inform the cost-effectiveness and value of information analyses, which were conducted alongside the pilot trial. Trial registration Current Controlled Trials ISRCTN69032034. PMID:22839453

Effect of Transitioning from Standard Reference Material 2806a to Standard Reference Material 2806b for Light Obscuration Particle Countering

DTIC Science & Technology

2016-04-01

Reference Material 2806b for Light Obscuration Particle Countering April 2016 UNCLASSIFIED UNCLASSIFIED Joel Schmitigal 27809 Standard Form 298 (Rev...Standard Reference Material 2806b for Light Obscuration Particle Countering 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Reference Material 2806a to Standard Reference Material 2806b for Light Obscuration Particle Countering Joel Schmitigal Force Projection

Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): reference data for the trunk and application in patients with chronic postherpetic neuralgia.

PubMed

Pfau, Doreen B; Krumova, Elena K; Treede, Rolf-Detlef; Baron, Ralf; Toelle, Thomas; Birklein, Frank; Eich, Wolfgang; Geber, Christian; Gerhardt, Andreas; Weiss, Thomas; Magerl, Walter; Maier, Christoph

2014-05-01

Age- and gender-matched reference values are essential for the clinical use of quantitative sensory testing (QST). To extend the standard test sites for QST-according to the German Research Network on Neuropathic Pain-to the trunk, we collected QST profiles on the back in 162 healthy subjects. Sensory profiles for standard test sites were within normal interlaboratory differences. QST revealed lower sensitivity on the upper back than the hand, and higher sensitivity on the lower back than the foot, but no systematic differences between these trunk sites. Age effects were significant for most parameters. Females exhibited lower pressure pain thresholds (PPT) than males, which was the only significant gender difference. Values outside the 95% confidence interval of healthy subjects (considered abnormal) required temperature changes of >3.3-8.2 °C for thermal detection. For cold pain thresholds, confidence intervals extended mostly beyond safety cutoffs, hence only relative reference data (left-right differences, hand-trunk differences) were sufficiently sensitive. For mechanical detection and pain thresholds, left-right differences were 1.5-2.3 times more sensitive than absolute reference data. The most sensitive parameter was PPT, where already side-to-side differences >35% were abnormal. Compared to trunk reference data, patients with postherpetic neuralgia exhibited thermal and tactile deficits and dynamic mechanical allodynia, mostly without reduced mechanical pain thresholds. This pattern deviates from other types of neuropathic pain. QST reference data for the trunk will also be useful for patients with postthoracotomy pain or chronic back pain. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Novel blood pressure and pulse pressure estimation based on pulse transit time and stroke volume approximation.

PubMed

Lee, Joonnyong; Sohn, JangJay; Park, Jonghyun; Yang, SeungMan; Lee, Saram; Kim, Hee Chan

2018-06-18

Non-invasive continuous blood pressure monitors are of great interest to the medical community due to their value in hypertension management. Recently, studies have shown the potential of pulse pressure as a therapeutic target for hypertension, but not enough attention has been given to non-invasive continuous monitoring of pulse pressure. Although accurate pulse pressure estimation can be of direct value to hypertension management and indirectly to the estimation of systolic blood pressure, as it is the sum of pulse pressure and diastolic blood pressure, only a few inadequate methods of pulse pressure estimation have been proposed. We present a novel, non-invasive blood pressure and pulse pressure estimation method based on pulse transit time and pre-ejection period. Pre-ejection period and pulse transit time were measured non-invasively using electrocardiogram, seismocardiogram, and photoplethysmogram measured from the torso. The proposed method used the 2-element Windkessel model to model pulse pressure with the ratio of stroke volume, approximated by pre-ejection period, and arterial compliance, estimated by pulse transit time. Diastolic blood pressure was estimated using pulse transit time, and systolic blood pressure was estimated as the sum of the two estimates. The estimation method was verified in 11 subjects in two separate conditions with induced cardiovascular response and the results were compared against a reference measurement and values obtained from a previously proposed method. The proposed method yielded high agreement with the reference (pulse pressure correlation with reference R ≥ 0.927, diastolic blood pressure correlation with reference R ≥ 0.854, systolic blood pressure correlation with reference R ≥ 0.914) and high estimation accuracy in pulse pressure (mean root-mean-squared error ≤ 3.46 mmHg) and blood pressure (mean root-mean-squared error ≤ 6.31 mmHg for diastolic blood pressure and ≤ 8.41 mmHg for systolic blood pressure) over a wide range of hemodynamic changes. The proposed pulse pressure estimation method provides accurate estimates in situations with and without significant changes in stroke volume. The proposed method improves upon the currently available systolic blood pressure estimation methods by providing accurate pulse pressure estimates.

[Study on blood pressure standard in children using the automatic sphygmomanometer].

PubMed

Niida, Mami; Hataya, Hiroshi; Honda, Masataka

2015-01-01

In Japan, two treatment guidelines exist for pediatric patients with hypertension. The Guidelines for Drug Therapy in Pediatric Patients with Cardiovascular Diseases (JCS2012), by the Japanese Circulation Society, cite the stethoscopy-based American guidelines. The Guidelines for the Management of Hypertension (JSH2009), by the Japanese Society of Hypertension, focus on Japanese data obtained from automated sphygmomanometry. The frequent use of automated sphygmomanometers in clinical practice implies that the JSH2009 guidelines might be better; however with strict low reference values for the diastolic phase, overtreatment may result. Only the Japanese Circulation Society's guidelines include a therapeutic strategy, and the Chronic Kidney Disease (CKD) Guide, CKD Guidelines, and school urinary screening tests all cite these guidelines on stethoscopy-based blood pressure determination. Stethoscopy should be conducted during a medical examination; however, due to limited time in clinical practice, most physicians use automated sphygmomanometers while nevertheless relying on the Japanese Circulation Society reference values--which are stethoscopy-based. To find a compromise, we compared reference values in Japan with those from South Korea (automated sphygmomanometer-based) and those from the United States (stethoscopy-based). Moreover, we examined the results of recent accuracy tests for automated sphygmomanometers. Although the JSH2009 reference values for the systolic phase were consistent with those in the United States (stethoscopy-based), the reference values for the diastolic phase were lower. We observed the same tendency when comparing JSH2009 reference values with those in South Korea (automated sphygmomanometer-based). Conversely, there were only small differences between automated sphygmomanometry and mercury measurement, and we found it was possible to substitute the values from automated sphygmomanometry for stethoscopy. A large-scale study that takes into account patient height, measurement method, and treatment criteria is required to establish appropriate reference values. Even if automated sphygmomanometry is used until appropriate values are established, we consider the criteria provided in the American guidelines as appropriate.

Application of reference-modified density functional theory: Temperature and pressure dependences of solvation free energy.

PubMed

Sumi, Tomonari; Maruyama, Yutaka; Mitsutake, Ayori; Mochizuki, Kenji; Koga, Kenichiro

2018-02-05

Recently, we proposed a reference-modified density functional theory (RMDFT) to calculate solvation free energy (SFE), in which a hard-sphere fluid was introduced as the reference system instead of an ideal molecular gas. Through the RMDFT, using an optimal diameter for the hard-sphere reference system, the values of the SFE calculated at room temperature and normal pressure were in good agreement with those for more than 500 small organic molecules in water as determined by experiments. In this study, we present an application of the RMDFT for calculating the temperature and pressure dependences of the SFE for solute molecules in water. We demonstrate that the RMDFT has high predictive ability for the temperature and pressure dependences of the SFE for small solute molecules in water when the optimal reference hard-sphere diameter determined for each thermodynamic condition is used. We also apply the RMDFT to investigate the temperature and pressure dependences of the thermodynamic stability of an artificial small protein, chignolin, and discuss the mechanism of high-temperature and high-pressure unfolding of the protein. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Urea cycle is enhanced by petit-high pressure carbon dioxide stress in yeast Saccharomyces cerevisiae

NASA Astrophysics Data System (ADS)

Niu, Liyuan; Nomura, Kazuki; Iwahashi, Hitoshi; Matsuoka, Hiroyuki; Kawachi, Satoshi; Suzuki, Yoshihisa; Tamura, Katsuhiro

2017-01-01

It has been demonstrated that pasteurized effect on microorganisms of petit-high pressure carbon dioxide (p-HPCD) with long time treatment is similar to the effect of HPCD with short time treatment. The 'petit-high pressure' refers to a pressure of 1.5-13 atm (standard atmosphere). After 0.5 MPa of CO2 at 25°C for 2 h treatment, specific growth rate of yeast cells in the logarithm phase was decreased by 50% approximately. Under this condition, our study analyzed transcriptional responses of Saccharomyces cerevisiae through the functional genomic approach. Transcription of 837 open reading frames (ORFs) was altered relative to cells without treatment and 476 ORFs were induced after p-HPCD treatment. These selected genes were then categorized by function of gene product using the Munich Information Centre for Protein Sequences database. Genes involved in 'metabolism of the urea cycle' were found to be significantly induced. This enhanced metabolic process could help to remove redundant ? in cellular interior, thereby decrease the production of ?. Liberation of H+ ion could be decreased along with the inhibition of ? dissociation.

Impact of a product-specific reference standard for the measurement of a PEGylated rFVIII activity: the Swiss Multicentre Field Study.

PubMed

Bulla, O; Poncet, A; Alberio, L; Asmis, L M; Gähler, A; Graf, L; Nagler, M; Studt, J-D; Tsakiris, D A; Fontana, P

2017-07-01

Measuring factor VIII (FVIII) activity can be challenging when it has been modified, such as when FVIII is pegylated to increase its circulating half-life. Use of a product-specific reference standard may help avoid this issue. Evaluate the impact of using a product-specific reference standard for measuring the FVIII activity of BAX 855 - a pegylated FVIII - in eight of Switzerland's main laboratories. Factor VIII-deficient plasma, spiked with five different concentrations of BAX 855, plus a control FVIII sample, was sent to the participating laboratories. They measured FVIII activity by using either with a one-stage (OSA) or the chromogenic assay (CA) against their local or a product-specific reference standard. When using a local reference standard, there was an overestimation of BAX 855 activity compared to the target concentrations, both with the OSA and CA. The use of a product-specific reference standard reduced this effect: mean recovery ranged from 127.7% to 213.5% using the OSA with local reference standards, compared to 110% to 183.8% with a product-specific reference standard, and from 146.3% to 182.4% using the CA with local reference standards compared to 72.7% to 103.7% with a product-specific reference standard. In this in vitro study, the type of reference standard had a major impact on the measurement of BAX 855 activity. Evaluation was more accurate and precise when using a product-specific reference standard. © 2017 John Wiley & Sons Ltd.

Improved spectrophotometric cell for hydrothermal solutions

USGS Publications Warehouse

Susak, N.J.; Crerar, D.A.; Forseman, T.C.; Haas, J.L.

1981-01-01

A simple, inexpensive spectrophotometric cell was designed for use with aqueous solutions for which temperature is a maximum of 325??C and pressure, 28 MPa. The cell has an internal volume of 5 ml and a path length of 1.31 cm. Each furnace assembly is 120 mm in diameter ?? 150 mm high and will fit into most commercial spectrophotometers. Temperature is controlled by a standard set-point controller and a balancing circuit that is used to maintain the temperature of the sample and reference cell within 1??C of each other at any temperature.

Preliminary flight prototype silver ion monitoring system

NASA Technical Reports Server (NTRS)

Brady, J.

1974-01-01

The design, fabrication, and testing of a preliminary flight prototype silver ion monitoring system based on potentiometric principles and utilizing a solid-state silver sulfide electrode paired with a pressurized double-junction reference electrode housing a replaceable electrolyte reservoir is described. The design provides automatic electronic calibration utilizing saturated silver bromide solution as a silver ion standard. The problem of loss of silver ion from recirculating fluid, its cause, and corrective procedures are reported. The instability of the silver sulfide electrode is discussed as well as difficulties met in implementing the autocalibration procedure.

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

PubMed

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.

Operating and environmental characteristics of Sigma Tau hydrogen masers used in the Very Long Baseline Array (VLBA)

NASA Technical Reports Server (NTRS)

Tucker, T. K.

1989-01-01

Presented here are the results obtained from performance evaluation of a pair of Sigma Tau Standards Corporation Model VLBA-112 active hydrogen maser frequency standards. These masers were manufactured for the National Radio Astronomy Observatory (NRAO) for use on the Very Long Baseline Array (VLBA) project and were furnished to the Jet Propulsion Laboratory (JPL) for the purpose of these tests. Tests on the two masers were performed in the JPL Frequency Standards Laboratory (FSL) and included the characterization of output frequency stability versus environmental factors such as temperature, humidity, magnetic field, and barometric pressure. The performance tests also included the determination of phase noise and Allan variance using both FSL and Sigma Tau masers as references. All tests were conducted under controlled laboratory conditions, with only the desired environmental and operational parameters varied to determine sensitivity to external environment.

Intraocular pressure in the smallest primate aging model: the gray mouse lemur.

PubMed

Dubicanac, Marko; Joly, Marine; Strüve, Julia; Nolte, Ingo; Mestre-Francés, Nadine; Verdier, Jean-Michel; Zimmermann, Elke

2018-05-01

The aim of this study was to assess the practicability of common tonometers used in veterinary medicine for rapid intraocular pressure (IOP) screening, to calibrate IOP values gained by the tonometers, and to define a reference IOP value for the healthy eye in a new primate model for aging research, the gray mouse lemur. TonoVet ® and the TonoPen ™ measurements were calibrated manometrically in healthy enucleated eyes of mouse lemurs euthanized for veterinary reasons. For comparison of the practicability of both tonometers as a rapid IOP assessment tool for living mouse lemurs, the IOP of 24 eyes of 12 animals held in the hand was measured. To define a standard reference value for IOP in mouse lemurs, 258 healthy animals were measured using the TonoVet ® . Intraocular pressure measurements for the TonoVet ® can be corrected using the formula: y = 0.981 + (1.962*TonoVet ® value), and those for the TonoPen ™ using that of y = 5.38 + (1.426*TonoPen ™ value). The calibrated IOP for a healthy mouse lemur eye was 20.3 ± 2.8 mmHg. The TonoVet ® showed advantages in practicability, for example, small corneal contact area, short and painless corneal contact, shortened total time spent on investigation, as well as the more accurate measured values. IOP measurements of healthy mouse lemur eyes were not affected by age, sex, eye side, or colony. Tonometry using TonoVet ® is the more practicable assessment tool for IOP measurement of the tiny eyes of living mouse lemurs. Pathological deviations can be identified based on the described reference value. © 2016 American College of Veterinary Ophthalmologists.

Automated measurement of pressure injury through image processing.

PubMed

Li, Dan; Mathews, Carol

2017-11-01

To develop an image processing algorithm to automatically measure pressure injuries using electronic pressure injury images stored in nursing documentation. Photographing pressure injuries and storing the images in the electronic health record is standard practice in many hospitals. However, the manual measurement of pressure injury is time-consuming, challenging and subject to intra/inter-reader variability with complexities of the pressure injury and the clinical environment. A cross-sectional algorithm development study. A set of 32 pressure injury images were obtained from a western Pennsylvania hospital. First, we transformed the images from an RGB (i.e. red, green and blue) colour space to a YC b C r colour space to eliminate inferences from varying light conditions and skin colours. Second, a probability map, generated by a skin colour Gaussian model, guided the pressure injury segmentation process using the Support Vector Machine classifier. Third, after segmentation, the reference ruler - included in each of the images - enabled perspective transformation and determination of pressure injury size. Finally, two nurses independently measured those 32 pressure injury images, and intraclass correlation coefficient was calculated. An image processing algorithm was developed to automatically measure the size of pressure injuries. Both inter- and intra-rater analysis achieved good level reliability. Validation of the size measurement of the pressure injury (1) demonstrates that our image processing algorithm is a reliable approach to monitoring pressure injury progress through clinical pressure injury images and (2) offers new insight to pressure injury evaluation and documentation. Once our algorithm is further developed, clinicians can be provided with an objective, reliable and efficient computational tool for segmentation and measurement of pressure injuries. With this, clinicians will be able to more effectively monitor the healing process of pressure injuries. © 2017 John Wiley & Sons Ltd.

Performance Characteristics of a New Generation Pressure Microsensor for Physiologic Applications

PubMed Central

Cottler, Patrick S.; Karpen, Whitney R.; Morrow, Duane A.; Kaufman, Kenton R.

2009-01-01

A next generation fiber-optic microsensor based on the extrinsic Fabry–Perot interferometric (EFPI) technique has been developed for pressure measurements. The basic physics governing the operation of these sensors makes them relatively tolerant or immune to the effects of high-temperature, high-EMI, and highly-corrosive environments. This pressure microsensor represents a significant improvement in size and performance over previous generation sensors. To achieve the desired overall size and sensitivity, numerical modeling of diaphragm deflection was incorporated in the design, with the desired dimensions and calculated material properties. With an outer diameter of approximately 250 µm, a dynamic operating range of over 250 mmHg, and a sampling frequency of 960 Hz, this sensor is ideal for the minimally invasive measurement of physiologic pressures and incorporation in catheter-based instrumentation. Nine individual sensors were calibrated and characterized by comparing the output to a U.S. National Institute of Standards and Technology (NIST) Traceable reference pressure over the range of 0–250 mmHg. The microsensor performance demonstrated accuracy of better than 2% full-scale output, and repeatability, and hysteresis of better than 1% full-scale output. Additionally, fatigue effects on five additional sensors were 0.25% full-scale output after over 10,000 pressure cycles. PMID:19495983

Bilateral comparison of 10 V standards between the NSAI-NML (Ireland) and the BIPM, February to March 2012 (part of the ongoing BIPM key comparison BIPM.EM-K11.b)

NASA Astrophysics Data System (ADS)

Power, O.; Solve, S.; Chayramy, R.; Stock, M.

2012-01-01

As part of the on-going BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out from February to March 2012. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_C (ZC) and BIPM_D (ZD), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (electromotive force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson voltage standard. Results of all measurements were corrected for the dependence of the output voltages on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the value assigned to DC voltage standard by NSAI-NML, at the level of 10 V, at NSAI-NML, UNML, and that assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 23 February 2012. UNML - UBIPM = +0.83 µV, uc = 1.35 µV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. The final result is impacted by the anomalous offset between the NSAI-NML results for the two transfer standards. The reason for this offset hasn't been determined. However, the difference remains within the total combined standard uncertainty. Therefore, the comparison result shows that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated expanded uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Investigation of the tone-burst tube for duct lining attenuation measurement

NASA Technical Reports Server (NTRS)

Soffel, A. R.; Morrow, P. F.

1972-01-01

The tone burst technique makes practical the laboratory evaluation of potential inlet and discharge duct treatments. Tone burst apparatus requires only simple machined parts and standard components. Small, simply made, lining samples are quickly and easily installed in the system. Two small electromagnetric loudspeaker drivers produce peak sound pressure level of over 166 db in the 3-square-inch sample duct. Air pump available in most laboratories can produce air flows of over plus and minus Mach 0.3 in the sample duct. The technique uses short shaped pulses of sound propagated down a progressive wave tube containing the sample duct. The peak pressure level output of the treated duct is compared with the peak pressure level output of a substituted reference duct. The difference between the levels is the attenuation or insertion loss of the treated duct. Evaluations of resonant absorber linings by the tone burst technique check attenuation values predicted by empirical formulas based on full scale ducts.

Application of the Benthic Ecosystem Quality Index 2 to benthos in Dutch transitional and coastal waters

NASA Astrophysics Data System (ADS)

van Loon, W. M. G. M.; Boon, A. R.; Gittenberger, A.; Walvoort, D. J. J.; Lavaleye, M.; Duineveld, G. C. A.; Verschoor, A. J.

2015-09-01

The Benthic Ecosystem Quality Index 2 (BEQI2) is the Dutch multi-metric index (MMI) for assessing the status and trend of benthic invertebrates in transitional and coastal waters for the Water Framework Directive (WFD). It contains the same indicators, i.e. species richness, Shannon index and AMBI, as in the multivariate m-AMBI. The latter MMI has been adopted by several European countries in the context of WFD implementation. In contrast to m-AMBI, the BEQI2 calculation procedure has been strongly simplified and consists of two steps, i.e. the separate indicator values are normalized using their long-term reference values resulting in three Ecological Quality Ratios (EQRs), which are subsequently averaged to give one BEQI2 value. Using this method only small numbers of samples need to be analysed by Dutch benthos laboratories annually, without the necessity to co-analyse a larger historical dataset. BEQI2 EQR values appeared to correlate quantitatively very well with m-AMBI EQR values. In addition, a data pooling procedure has been added to the BEQI2 tool which enables the pooling of small core samples (0.01-0.025 m2) into larger standardized data pools of 0.1 m2 in order to meet the data requirements of the AMBI indicator and to obtain comparable reference values. Furthermore, the BEQI2 tool automatically and efficiently converts species synonym names into standardized species names. The BEQI2 tool has been applied to all Dutch benthos data monitored by Rijkswaterstaat in the period of 1991-2010 in the transitional and coastal waters and salt lakes and these results are reported here for the first time. Reference values for species richness and Shannon index (99 percentile values) and AMBI reference values (1 percentile values) were estimated for all water body-ecotopes and are discussed. BEQI2 results for all these water bodies are discussed in view of natural and human pressures. The pressure sensitivity of the BEQI2 for sewage and dredging/dumping, via the state variables oxygen and suspended matter respectively, was demonstrated.

Effect of reference conditions on flow rate, modifier fraction and retention in supercritical fluid chromatography.

PubMed

De Pauw, Ruben; Shoykhet Choikhet, Konstantin; Desmet, Gert; Broeckhoven, Ken

2016-08-12

When using compressible mobile phases such as fluidic CO2, the density, the volumetric flow rates and volumetric fractions are pressure dependent. The pressure and temperature definition of these volumetric parameters (referred to as the reference conditions) may alter between systems, manufacturers and operating conditions. A supercritical fluid chromatography system was modified to operate in two modes with different definition of the eluent delivery parameters, referred to as fixed and variable mode. For the variable mode, the volumetric parameters are defined with reference to the pump operating pressure and actual pump head temperature. These conditions may vary when, e.g. changing the column length, permeability, flow rate, etc. and are thus variable reference conditions. For the fixed mode, the reference conditions were set at 150bar and 30°C, resulting in a mass flow rate and mass fraction of modifier definition which is independent of the operation conditions. For the variable mode, the mass flow rate of carbon dioxide increases with system pump operating pressure, decreasing the fraction of modifier. Comparing the void times and retention factor shows that the deviation between the two modes is almost independent of modifier percentage, but depends on the operating pressure. Recalculating the set volumetric fraction of modifier to the mass fraction results in the same retention behaviour for both modes. This shows that retention in SFC can be best modelled using the mass fraction of modifier. The fixed mode also simplifies method scaling as it only requires matching average column pressure. Copyright © 2016 Elsevier B.V. All rights reserved.

Chemical thermodynamic data. 1. The concept of links to the chemical elements and the historical development of key thermodynamic data [plus Supplementary Electronic Annex 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolery, Thomas J.; Jove Colon, Carlos F.

Chemical thermodynamic data remain a keystone for geochemical modeling and reactive transport simulation as applied to an increasing number of applications in the earth sciences, as well as applications in other areas including metallurgy, material science, and industrial process design. The last century has seen the development of a large body of thermodynamic data and a number of major compilations. The past several decades have seen the development of thermodynamic databases in digital form designed to support computer calculations. However, problems with thermodynamic data appear to be persistent. One problem pertains to the use of inconsistent primary key reference data.more » Such data pertain to elemental reference forms and key, stoichiometrically simple chemical species including metal oxides, CO 2, water, and aqueous species such as Na + and Cl -. A consistent set of primary key data (standard Gibbs energies, standard enthalpies, and standard entropies for key chemical species) for 298.15K and 1 bar pressure is essential. Thermochemical convention is to define the standard Gibbs energy and the standard enthalpy of an individual chemical species in terms of formation from reference forms of the constituent chemical elements. We propose a formal concept of “links” to the elemental reference forms. This concept involves a documented understanding of all reactions and calculations leading to values for a formation property (standard Gibbs energy or enthalpy). A valid link consists of two parts: (a) the path of reactions and corrections and (b) the associated data, which are key data. Such a link differs from a bare “key” or “reference” datum in that it requires additional information. Some or all of its associated data may also be key data. In evaluating a reported thermodynamic datum, one should identify the links to the chemical elements, a process which can be time-consuming and which may lead to a dead end (an incomplete link). The use of two or more inconsistent links to the same elemental reference form in a thermodynamic database will result in an inconsistency in the database. Thus, in constructing a database, it is important to establish a set of reliable links (generally resulting in a set of primary reference data) and then correct all data adopted subsequently for consistency with that set. Recommended values of key data have not been constant through history. We review some of this history through the lens of major compilations and other influential reports, and note a number of problem areas. Finally, we illustrate the concepts developed in this paper by applying them to some key species of geochemical interest, including liquid water; quartz and aqueous silica; and gibbsite, corundum, and the aqueous aluminum ion.« less

Chemical thermodynamic data. 1. The concept of links to the chemical elements and the historical development of key thermodynamic data [plus Supplementary Electronic Annex 2

DOE PAGES

Wolery, Thomas J.; Jove Colon, Carlos F.

2016-09-26

Chemical thermodynamic data remain a keystone for geochemical modeling and reactive transport simulation as applied to an increasing number of applications in the earth sciences, as well as applications in other areas including metallurgy, material science, and industrial process design. The last century has seen the development of a large body of thermodynamic data and a number of major compilations. The past several decades have seen the development of thermodynamic databases in digital form designed to support computer calculations. However, problems with thermodynamic data appear to be persistent. One problem pertains to the use of inconsistent primary key reference data.more » Such data pertain to elemental reference forms and key, stoichiometrically simple chemical species including metal oxides, CO 2, water, and aqueous species such as Na + and Cl -. A consistent set of primary key data (standard Gibbs energies, standard enthalpies, and standard entropies for key chemical species) for 298.15K and 1 bar pressure is essential. Thermochemical convention is to define the standard Gibbs energy and the standard enthalpy of an individual chemical species in terms of formation from reference forms of the constituent chemical elements. We propose a formal concept of “links” to the elemental reference forms. This concept involves a documented understanding of all reactions and calculations leading to values for a formation property (standard Gibbs energy or enthalpy). A valid link consists of two parts: (a) the path of reactions and corrections and (b) the associated data, which are key data. Such a link differs from a bare “key” or “reference” datum in that it requires additional information. Some or all of its associated data may also be key data. In evaluating a reported thermodynamic datum, one should identify the links to the chemical elements, a process which can be time-consuming and which may lead to a dead end (an incomplete link). The use of two or more inconsistent links to the same elemental reference form in a thermodynamic database will result in an inconsistency in the database. Thus, in constructing a database, it is important to establish a set of reliable links (generally resulting in a set of primary reference data) and then correct all data adopted subsequently for consistency with that set. Recommended values of key data have not been constant through history. We review some of this history through the lens of major compilations and other influential reports, and note a number of problem areas. Finally, we illustrate the concepts developed in this paper by applying them to some key species of geochemical interest, including liquid water; quartz and aqueous silica; and gibbsite, corundum, and the aqueous aluminum ion.« less

Reference Pricing Changes The 'Choice Architecture' Of Health Care For Consumers.

PubMed

Robinson, James C; Brown, Timothy T; Whaley, Christopher

2017-03-01

Reference pricing in health insurance creates incentives for patients to select for nonemergency services providers that charge relatively low prices and still offer high quality of care. It changes the "choice architecture" by offering standard coverage if the patient chooses cost-effective providers but requires considerable consumer cost sharing if more expensive alternatives are selected. The short-term impact of reference pricing has been to shift patient volumes from hospital-based to freestanding surgical, diagnostic, imaging, and laboratory facilities. This article summarizes reference pricing's impacts to date on patient choice, provider prices, surgical complications, and employer spending and estimates its potential impacts if expanded to more services and a broader population. Reference pricing induces consumers to select lower-price alternatives for all of the forms of care studied, leading to significant reductions in prices paid and spending incurred by insurers and employers. The impact on consumer cost sharing is mixed, with some studies finding higher copayments and some lower. We conclude with a discussion of the incentives created for providers to redesign their clinical processes and for efficient providers to expand into price-sensitive markets. Over time, reference pricing may increase pressures for price competition and lead to further cost-reducing innovations in health care products and processes. Project HOPE—The People-to-People Health Foundation, Inc.

FirefOx Design Reference fO2 Sensor for Hot, Deep Atmospheres

NASA Astrophysics Data System (ADS)

Izenberg, N.; Papadakis, S.; Deglau, D.; Francomacaro, A. S.

2016-12-01

Understanding the composition of the lowest portion of Venus' atmosphere is critical to knowing the stable mineralogy of the rocks there. Oxygen gas is a critical trace component, with fugacity, or partial pressure, estimated in the range of 10-19 to 10-22 from early probe measurements down to 22km altitude (Pioneer Venus, Venera), chemical equilibrium measurements, and other modeling. "FirefOx" is a simple oxygen fugacity sensor with the express purpose of determining the partial pressure of oxygen in the lowest scale heights of the Venus atmosphere, and especially the lowest hundreds of meters; the surface atmosphere interface, where the atmosphere and surface move to thermodynamic equilibrium. Knowledge of the fO2 at the surface atmosphere interface is crucial to determining the stable mineralogy of surface materials (e.g. magnetite vs. hematite) and gas chemistry in the near-surface atmosphere FirefOx is a Metal/Metal Oxide oxygen fugacity sensor intended to be mounted on the outside of a Venus descent probe, with electronics housed inside a thermally controlled environment. The sole sensor capability is the precise, accurate detection of the partial pressure of oxygen gas (fO2) in the near-surface environment of Venus, at up to 95-bar pressure (predominantly CO2. Surface temperatures at mean planetary elevation are near 735 K, thus a required operational temperature range of 710-740 K covers a range of near-surface elevations. FirefOx system requirements are low ( 100-200 grams, mass, milliwatt power, several kilobytes total science data). A design reference sensor, composed of custom, Yittria-ZrO ceramic electrolyte, with an encapsulated Pd/PdO standard and patterned Pt electrodes has demonstrated scientifically useful signal-to-noise millivolt level potential at temperatures as low as 620 K, relatable to fO2 by a Nernst equation E = RT/4F ln(PO2/PrefO2) where E = open circuit potential across the sensor electrolyte, R = universal gas constant, T = temperature, F = Faraday constant, PrefO2 = reference oxygen pressure, and PO2 = unknown oxygen pressure of the outside environment. The FirefOx sensor shows promise for direct fO2 measurement on potential upcoming Venus in situ and other deep atmosphere probes.

A novel fiber-optic measurement system for the evaluation of performances of neonatal pulmonary ventilators

NASA Astrophysics Data System (ADS)

Battista, L.; Scorza, A.; Botta, F.; Sciuto, S. A.

2016-02-01

Published standards for the performance evaluation of pulmonary ventilators are mainly directed to manufacturers rather than to end-users and often considered inadequate or not comprehensive. In order to contribute to overcome the problems above, a novel measurement system was proposed and tested with waveforms of mechanical ventilation by means of experimental trials carried out with infant ventilators typically used in neonatal intensive care units: the main quantities of mechanical ventilation in newborns are monitored, i.e. air flow rate, differential pressure and volume from infant ventilator are measured by means of two novel fiber-optic sensors (OFSs) developed and characterized by the authors, while temperature and relative humidity of air mass are obtained by two commercial transducers. The proposed fiber-optic sensors (flow sensor Q-OFS, pressure sensor P-OFS) showed measurement ranges of air flow and pressure typically encountered in neonatal mechanical ventilation, i.e. the air flow rate Q ranged from 3 l min-1 to 18 l min-1 (inspiratory) and from  -3 l min-1 to  -18 l min-1 (expiratory), the differential pressure ΔP ranged from  -15 cmH2O to 15 cmH2O. In each experimental trial carried out with different settings of the ventilator, outputs of the OFSs are compared with data from two reference sensors (reference flow sensor RF, reference pressure sensor RP) and results are found consistent: flow rate Q showed a maximum error between Q-OFS and RF up to 13 percent, with an output ratio Q RF/Q OFS of not more than 1.06  ±  0.09 (least square estimation, 95 percent confidence level, R 2 between 0.9822 and 0.9931). On the other hand the maximum error between P-OFS and RP on differential pressure ΔP was lower than 10 percent, with an output ratio ΔP RP/ΔP OFS between 0.977  ±  0.022 and 1.0  ±  0.8 (least square estimation, 95 percent confidence level, R 2 between 0.9864 and 0.9876). Despite the possible improvements, results were encouraging and suggested the proposed measurement system can be considered suitable for performances evaluation of neonatal ventilators and useful for both end-users and manufacturers.

Evaluation of a tunable bandpass reaction cell inductively coupled plasma mass spectrometer for the determination of selenium in serum and urine

NASA Astrophysics Data System (ADS)

Nixon, David E.; Neubauer, Kenneth R.; Eckdahl, Steven J.; Butz, John A.; Burritt, Mary F.

2003-01-01

A Dynamic Reaction Cell™ inductively coupled plasma mass spectrometer (DRC-ICP-MS) was evaluated for the determination of selenium in serum and urine. Reaction cell conditions were evaluated for the suppression of Ar 2+ dimer at m/ z 78 and 80 using methane as the reaction gas. A diluent containing 10% ethanol, 1% nitric acid, 0.5% Triton X-100 with gallium and yttrium internal standards was used to dilute urine and serum samples. Instrument response calibration was achieved by using aqueous acidic standards spiked into a urine matrix. Slopes for aqueous inorganic selenium, seleno- DL-cystine, seleno- DL-methionine and trimethylselenonium iodide spiked into urine and serum matrices were nearly identical. In general, reagent blank readings and detection limits were significantly lower in the DRC mode (reaction cell pressurized) than the standard mode (cell vented). Average results for the analysis of National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1598 bovine serum (attained over 13 days) are: 43.8±3.6 μg Se/l. Reference concentration is 43.6±3.6 μg Se/l. For NIST SRM 2670 Normal Urine the DRC-ICP-MS results are 30.7±4.6 μg Se/l with a certified concentration of 30±8 μg Se/l. For NIST SRM 2670 Elevated Urine the DRC-ICP-MS results are 463±35 μg Se/l with a certified concentration of 460±30 μg Se/l. The DRC-ICP-MS results for selenium determinations in urine and serum survey samples from the Institut National de Sante Publique du Quebec were compared with the reference concentrations and results produced by conventional ICP-MS. While conventional ICP-MS gave acceptable results for survey samples, DRC-ICP-MS gave excellent results for both urine and sera. Closer correlation was observed for DRC-ICP-MS results with target concentrations than with conventional ICP-MS.

Systematic review of decreased intracranial pressure with optimal head elevation in postcraniotomy patients: a meta-analysis.

PubMed

Jiang, Yan; Ye, Zeng pan-pan; You, Chao; Hu, Xin; Liu, Yi; Li, Hao; Lin, Sen; Li, Ji-Pin

2015-10-01

To determine an optimal head elevation degree to decrease intracranial pressure in postcraniotomy patients by meta-analysis. A change in head position can lead to a change in intracranial pressure; however, there are conflicting data regarding the optimal degree of elevation that decreases intracranial pressure in postcraniotomy patients. Quantitative systematic review with meta-analysis following Cochrane methods. The data were collected during 2014; three databases (PubMed, Embase and China National Knowledge Internet) were searched for published and unpublished studies in English. The bibliographies of the articles were also reviewed. The inclusion criteria referred to different elevation degrees and effects on intracranial pressure in postcraniotomy patients. According to pre-determined inclusion criteria and exclusion criteria, two reviewers extracted the eligible studies using a standard data form. These included a total of 237 participants who were included in the meta-analysis. (1) Compared with 0 degree: 10, 15, 30 and 45 degrees of head elevation resulted in lower intracranial pressure. (2) Intracranial pressure at 30 degrees was not significantly different in comparison to 45 degrees and was lower than that at 10 and 15 degrees. Patients with increased intracranial pressure significantly benefitted from a head elevation of 10, 15, 30 and 45 degrees compared with 0 degrees. A head elevation of 30 or 45 degrees is optimal for decreasing intracranial pressure. Research about the relationship of position changes and the outcomes of patient primary diseases is absent. © 2015 John Wiley & Sons Ltd.

[Application of traditional Chinese medicine reference standards in quality control of Chinese herbal pieces].

PubMed

Lu, Tu-Lin; Li, Jin-Ci; Yu, Jiang-Yong; Cai, Bao-Chang; Mao, Chun-Qin; Yin, Fang-Zhou

2014-01-01

Traditional Chinese medicine (TCM) reference standards plays an important role in the quality control of Chinese herbal pieces. This paper overviewed the development of TCM reference standards. By analyzing the 2010 edition of Chinese pharmacopoeia, the application of TCM reference standards in the quality control of Chinese herbal pieces was summarized, and the problems exiting in the system were put forward. In the process of improving the quality control level of Chinese herbal pieces, various kinds of advanced methods and technology should be used to research the characteristic reference standards of Chinese herbal pieces, more and more reasonable reference standards should be introduced in the quality control system of Chinese herbal pieces. This article discussed the solutions in the aspect of TCM reference standards, and future development of quality control on Chinese herbal pieces is prospected.

Chromium:forsterite laser frequency comb stabilization and development of portable frequency references inside a hollow optical fiber

NASA Astrophysics Data System (ADS)

Thapa, Rajesh

We have made significant accomplishments in the development of portable frequency standard inside hollow optical fibers. Such standards will improve portable optical frequency references available to the telecommunications industry. Our approach relies on the development of a stabilized Cr:forsterite laser to generate the frequency comb in the near-IR region. This laser is self referenced and locked to a CW laser which in turn is stabilized to a sub-Doppler feature of a molecular transition. The molecular transition is realized using a hollow core fiber filled with acetylene gas. We finally measured the absolute frequency of these molecular transitions to characterize the references. In this thesis, the major ideas, techniques and experimental results for the development and absolute frequency measurement of the portable frequency references are presented. A prism-based Cr:forsterite frequency comb is stabilized. We have effectively used the prism modulation along with power modulation inside the cavity in order to actively stabilize the frequency comb. We have also studied the carrier-envelope-offset frequency (f0) dynamics of the laser and its effect on laser stabilization. A reduction of f0 linewidth from ˜2 MHz to ˜20 kHz has also been observed. Both our in-loop and out-of-loop measurements of the comb stability showed that the comb is stable within a part in 1011 at 1-s gate time and is currently limited by our reference signal. In order to develop this portable frequency standard, saturated absorption spectroscopy is performed on the acetylene v1 + v3 band near 1532 nm inside different kinds of hollow optical fibers. The observed linewidths are a factor 2 narrower in the 20 mum fiber as compared to 10 mum fiber, and vary from 20-40 MHz depending on pressure and power. The 70 mum kagome fiber shows a further reduction in linewidth to less than 10 MHz. In order to seal the gas inside the hollow optical fiber, we have also developed a technique of splicing the hollow fiber to solid fiber in a standard commercial arc splicer, rather than the more expensive filament splicer, and achieved comparable splice loss. We locked a CW laser to the saturated absorption feature using a Frequency Modulation technique and then compared to an optical frequency comb. The stabilized frequency comb, providing a dense grid of reference frequencies in near-infrared region is used to characterize and measure the absolute frequency reference based on these hollow optical fibers.

Improving the Traceability of Meteorological Measurements at Automatic Weather Stations in Thailand

NASA Astrophysics Data System (ADS)

Keawprasert, T.; Sinhaneti, T.; Phuuntharo, P.; Phanakulwijit, S.; Nimsamer, A.

2017-08-01

A joint project between the National Institute of Metrology Thailand (NIMT) and the Thai Meteorology Department (TMD) was established for improving the traceability of meteorology measurements at automatic weather stations (AWSs) in Thailand. The project aimed to improve traceability of air temperature, relative humidity and atmospheric pressure by implementing on-site calibration facilities and developing of new calibration procedures. First, new portable calibration facilities for air temperature, humidity and pressure were set up as working standard of the TMD. A portable humidity calibrator was applied as a uniform and stable source for calibration of thermo-hygrometers. A dew-point hygrometer was employed as reference hygrometer and a platinum resistance thermometer (PRT) traceable to NIMT was used as reference thermometer. The uniformity and stability in both temperature and relative humidity were characterized at NIMT. A transportable pressure calibrator was used for calibration of air pressure sensor. The estimate overall uncertainty of the calibration setup is 0.2 K for air temperature, 1.0 % for relative humidity and 0.2 hPa for atmospheric pressure, respectively. Second, on-site calibration procedures were developed and four AWSs in the central part and the northern of Thailand were chosen as pilot stations for on-site calibration using the new calibration setups and developed calibration procedures. At each station, the calibration was done at the minimum temperature, average temperature and maximum temperature of the year, for air temperature, 20 %, 55 % and 90 % for relative humidity at the average air temperature of that station and at a one-year statistics pressure range for atmospheric pressure at ambient temperature. Additional in-field uncertainty contributions such as the temperature dependence on relative humidity measurement were evaluated and included in the overall uncertainty budget. Preliminary calibration results showed that using a separate PRT probe at these AWSs would be recommended for improving the accuracy of air temperature measurement. In case of relative humidity measurement, the data logger software is needed to be upgraded for achieving higher accuracy of less than 3 %. For atmospheric pressure measurement, a higher accuracy barometer traceable to NIMT could be used to reduce the calibration uncertainty to below 0.2 hPa.

Validation of the Medipro MediCare 100f upper arm blood pressure monitor, for self-measurement, according to the European Society of Hypertension International Protocol revision 2010.

PubMed

Yi, Jun; Wan, Yi; Pan, Feng; Yu, Xiaorong; Zhao, Huadong; Shang, Fujun; Xu, Yongyong

2011-08-01

The validation of sphygmomanometer is important in accurate blood pressure measurement. This study presents the validation results by the Medipro MediCare 100f upper arm blood pressure monitor according to the European Society of Hypertension International Protocol (ESH-IP) revision 2010. The ESH-IP revision 2010 for the validation of blood pressure measuring devices in adults was followed precisely. A total of 99 couples of test device and reference blood pressure measurements were obtained during the study (three pairs for each of the 33 participants). The device produced 73, 93, and 98 measurements within 5, 10, and 15 mmHg for systolic blood pressure (SBP) and 79, 93, and 96 for diastolic blood pressure (DBP), respectively. The mean standard deviation device-observer difference was 1.4 ± 5.2 mmHg for SBP and 0.02±5.8 mmHg for DBP. The number of participants with two or three of the device-observer differences within 5 mmHg was 24 for SBP and 30 for DBP, whereas there was no participant with none of the device-observer differences within 5 mmHg. According to the results of the validation study based on the ESH-IP revision 2010, the Medipro MediCare 100f can be recommended for self-measurement in an adult population.

Defining a reference range for vital signs in healthy term pregnant women undergoing caesarean section.

PubMed

Dennis, A; Hardy, L

2016-11-01

Early warning systems (EWS), used to identify deteriorating hospitalised patients, are based on measurement of vital signs. When the patients are pregnant, most EWS still use non-pregnant reference ranges of vital signs to determine trigger thresholds. There are no published reference ranges for all vital signs in pregnancy. We aimed to define vital signs reference ranges for term pregnancy in the preoperative period, and to determine the appropriateness of EWS trigger criteria in pregnancy. We conducted a one-year retrospective study in a tertiary referral obstetric hospital. The study sample was healthy term women undergoing planned caesarean section (CS). Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), oxygen saturation (SpO 2 ) and temperature were all measured automatically and data was extracted from the medical record. Two hundred and fifty-eight women met inclusion criteria. Results were (mean ± SD [standard deviation]) SBP 118 ± 11.2 mmHg, DBP 75 ± 10.3 mmHg, HR 84 ± 10.2 /minute, respiratory rate 18 ± 1.5 /minute, SpO 2 99%  ± 1.0% and temperature 36.4°C ± 0.43°C. The reference ranges (mean ± 2SD) determined were SBP 96-140 mmHg, DBP 54-96 mmHg, HR 64-104/minute, RR 15-21 /minute, SpO 2 97%-100% and temperature 35.5°C-37.3°C. This study defined a reference range for vital signs in healthy term pregnant women undergoing CS. Study findings suggest that currently used criteria for EWS triggers, based on non-pregnant values, may be too extreme for timely detection of deteriorating pregnant patients. Further research examining the modified HR triggers of ≤50 and ≥110 /minute in pregnant women and their relationship to clinical outcomes is required.

Generation and validation of oxygenated volatile organic carbon standards for the 1995 Southern Oxidants Study Nashville Intensive

NASA Astrophysics Data System (ADS)

Apel, E. C.; Calvert, J. G.; Greenberg, J. P.; Riemer, D.; Zika, R.; Kleindienst, T. E.; Lonneman, W. A.; Fung, K.; Fujita, E.

1998-09-01

Two volatile organic compound (VOC) mixtures were made available and utilized for the calibration of instruments and intercomparison exercises at the Youth, Inc. (YI) site during the Southern Oxidants Study Nashville Intensive. Cylinder 1, made by Scott-Marrin, Inc., contained 14 components (3 nonmethane hydrocarbons (NMHCs) and 11 oxygen-containing VOCs (OVOCs)) and is referred to as OVOCl. Cylinder 2, made at the National Center for Atmospheric Research (NCAR), contained 4 components (one NMHC and three OVOCs) and is referred to as OVOC2. The mixtures were not prepared by either laboratory as primary standards but significant effort was applied to validate their concentrations by several different laboratories using several different techniques. The mixtures were prepared in high-pressure cylinders in the parts per million by volume (ppmv) range using calibrated syringe methods. Gas Chromatographic (GC) and 2,4-dinitrophenylhydrazine (DNPH) cartridge/high-pressure liquid Chromatographic (HPLC) systems were utilized in the calibration of the cylinders. GC detectors included the flame ionization detector (FID) and atomic emission detector (AED). Results obtained with the GC/FID systems for OVOCs were adjusted in terms of the effective carbon number (ECN), obtained from literature values, to correct for the reduced response of the FID for compounds containing oxygen, relative to compounds containing only carbon and hydrogen. Cylinder concentrations were derived and compared based on the ECN-adjusted FID results, the AED results, and the DNPH cartridge results. The various methods employed agreed to within approximately 15%. Both cylinders were stable (±4%) over a period of 2 years.

A critical comparison of several low Reynolds number k-epsilon turbulence models for flow over a backward facing step

NASA Technical Reports Server (NTRS)

Steffen, C. J., Jr.

1993-01-01

Turbulent backward-facing step flow was examined using four low turbulent Reynolds number k-epsilon models and one standard high Reynolds number technique. A tunnel configuration of 1:9 (step height: exit tunnel height) was used. The models tested include: the original Jones and Launder; Chien; Launder and Sharma; and the recent Shih and Lumley formulation. The experimental reference of Driver and Seegmiller was used to make detailed comparisons between reattachment length, velocity, pressure, turbulent kinetic energy, Reynolds shear stress, and skin friction predictions. The results indicated that the use of a wall function for the standard k-epsilon technique did not reduce the calculation accuracy for this separated flow when compared to the low turbulent Reynolds number techniques.

Bilateral comparison of 1 V and 10 V standards between the NMISA (South Africa) and the BIPM April to June 2017 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Matlejoane, A. M.; Magagula, L.; Stock, M.

2018-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and the National Metrology Institute of South Africa, NMISA (South Africa), was carried out from April to June 2017. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPMA (ZA) and BIPMB (ZB), were transported by freight to NMISA and back to BIPM. In order to keep the Zeners powered during their transportation phase, a voltage stabilizer developed by BIPM was connected in parallel to the internal battery. It consists of a set of two batteries, electrically protected from surcharge-discharge, easy to recharge and is designed to power two transfer standards for ten consecutive days. At NMISA, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at NMISA, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by NMISA, at the level of 1.018 V and 10 V, at NMISA, UNMISA, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference dates of the 19th and 18th of May 2017, respectively. UNMISA - UBIPM = + 0.07 μV uc = 0.02 μV, at 1.018 V UNMISA - UBIPM = + 0.001 μV uc = 0.34 μV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NMISA, based on KJ-90, and the uncertainty related to the comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 V and 10 V standards between the DEFNAT (Tunisia) and the BIPM February to March 2016 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

NASA Astrophysics Data System (ADS)

Solve, S.; Chayramy, R.; Ben Salah, B.; Mallat, A.; Abene, L.; Stock, M.

2016-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Laboratoire de Métrologie Electrique, DEFNAT (Tunisia), was carried out from February to March 2016. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPMC (ZC) and BIPM6 (Z6), were transported by freight to DEFNAT and back to BIPM. In order to keep the Zeners powered during their transportation phase, a BIPM in-house voltage stabiliser was connected in parallel to the internal battery. The voltage stabiliser consists of a set of two batteries, electrically protected from surcharge-discharge, easy to recharge and is designed to power two transfer standards for 10 consecutive days. At DEFNAT, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at DEFNAT, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by DEFNAT, at the level of 1.018 V and 10 V, at DEFNAT, UDEFNAT, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 26th of February 2016. UDEFNAT - UBIPM = + 0.07 μV uc = 0.04 μV, at 1.018 V UDEFNAT - UBIPM = + 0.38 μV uc = 0.10 μV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Research study on neutral thermodynamic atmospheric model. [for space shuttle mission and abort trajectory

NASA Technical Reports Server (NTRS)

Hargraves, W. R.; Delulio, E. B.; Justus, C. G.

1977-01-01

The Global Reference Atmospheric Model is used along with the revised perturbation statistics to evaluate and computer graph various atmospheric statistics along a space shuttle reference mission and abort trajectory. The trajectory plots are height vs. ground range, with height from ground level to 155 km and ground range along the reentry trajectory. Cross sectional plots, height vs. latitude or longitude, are also generated for 80 deg longitude, with heights from 30 km to 90 km and latitude from -90 deg to +90 deg, and for 45 deg latitude, with heights from 30 km to 90 km and longitudes from 180 deg E to 180 deg W. The variables plotted are monthly average pressure, density, temperature, wind components, and wind speed and standard deviations and 99th inter-percentile range for each of these variables.

Right ventricular diastolic performance in children with pulmonary arterial hypertension associated with congenital heart disease: correlation of echocardiographic parameters with invasive reference standards by high-fidelity micromanometer catheter.

PubMed

Okumura, Kenichi; Slorach, Cameron; Mroczek, Dariusz; Dragulescu, Andreea; Mertens, Luc; Redington, Andrew N; Friedberg, Mark K

2014-05-01

Right ventricular diastolic dysfunction influences outcomes in pulmonary arterial hypertension (PAH), but echocardiographic parameters have not been investigated in relation to invasive reference standards in pediatric PAH. We investigated echocardiographic parameters of right ventricular diastolic function in children with PAH in relation to simultaneously measured invasive reference measures. We prospectively recruited children undergoing a clinically indicated cardiac catheterization for evaluation of PAH and pulmonary vasoreactivity testing. Echocardiography was performed simultaneously with invasive reference measurements by high-fidelity micromanometer catheter. For analysis, patients were divided into shunt and nonshunt groups. Sixteen children were studied. In the group as a whole, significant correlations were found among τ and tricuspid deceleration time, E', E/E', TimeE-E', A wave velocity, and global early and late diastolic strain rate. dp/dt minimum correlated significantly with late diastolic tricuspid annular velocity (A'), tissue Doppler imaging-derived systolic:diastolic duration ratio, and global late diastolic strain rate. End-diastolic pressure correlated significantly with tissue Doppler imaging-derived systolic:diastolic duration ratio. On multivariate analysis, tricuspid deceleration time, TimeE-E', and global early diastolic strain rate were independent predictors of τ, whereas tissue Doppler imaging-derived systolic:diastolic duration ratio was an independent predictor of dp/dt minimum. In general, correlations between echocardiographic and invasive parameters were better in the shunt group than in the nonshunt group. Echocardiography correlates with invasive reference measures of right ventricular diastolic function in children with PAH, although it does not differentiate between early versus late diastolic abnormalities. Newer echocardiographic techniques may have added value to assess right ventricular diastolic dysfunction in this population. © 2014 American Heart Association, Inc.

Blood pressure variability in man: its relation to high blood pressure, age and baroreflex sensitivity.

PubMed

Mancia, G; Ferrari, A; Gregorini, L; Parati, G; Pomidossi, G; Bertinieri, G; Grassi, G; Zanchetti, A

1980-12-01

1. Intra-arterial blood pressure and heart rate were recorded for 24 h in ambulant hospitalized patients of variable age who had normal blood pressure or essential hypertension. Mean 24 h values, standard deviations and variation coefficient were obtained as the averages of values separately analysed for 48 consecutive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation aations and variation coefficient were obtained as the averages of values separately analysed for 48 consecurive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for heart rate were smaller. 3. In hypertensive subjects standard deviation for mean arterial pressure was greater than in normotensive subjects of similar ages, but this was not the case for variation coefficient, which was slightly smaller in the former than in the latter group. Normotensive and hypertensive subjects showed no difference in standard deviation and variation coefficient for heart rate. 4. In both normotensive and hypertensive subjects standard deviation and even more so variation coefficient were slightly or not related to arterial baroreflex sensitivity as measured by various methods (phenylephrine, neck suction etc.). 5. It is concluded that blood pressure variability increases and heart rate variability decreases with age, but that changes in variability are not so obvious in hypertension. Also, differences in variability among subjects are only marginally explained by differences in baroreflex function.

Pressurized Pepsin Digestion in Proteomics

PubMed Central

López-Ferrer, Daniel; Petritis, Konstantinos; Robinson, Errol W.; Hixson, Kim K.; Tian, Zhixin; Lee, Jung Hwa; Lee, Sang-Won; Tolić, Nikola; Weitz, Karl K.; Belov, Mikhail E.; Smith, Richard D.; Paša-Tolić, Ljiljana

2011-01-01

Integrated top-down bottom-up proteomics combined with on-line digestion has great potential to improve the characterization of protein isoforms in biological systems and is amendable to high throughput proteomics experiments. Bottom-up proteomics ultimately provides the peptide sequences derived from the tandem MS analyses of peptides after the proteome has been digested. Top-down proteomics conversely entails the MS analyses of intact proteins for more effective characterization of genetic variations and/or post-translational modifications. Herein, we describe recent efforts toward efficient integration of bottom-up and top-down LC-MS-based proteomics strategies. Since most proteomics separations utilize acidic conditions, we exploited the compatibility of pepsin (where the optimal digestion conditions are at low pH) for integration into bottom-up and top-down proteomics work flows. Pressure-enhanced pepsin digestions were successfully performed and characterized with several standard proteins in either an off-line mode using a Barocycler or an on-line mode using a modified high pressure LC system referred to as a fast on-line digestion system (FOLDS). FOLDS was tested using pepsin and a whole microbial proteome, and the results were compared against traditional trypsin digestions on the same platform. Additionally, FOLDS was integrated with a RePlay configuration to demonstrate an ultrarapid integrated bottom-up top-down proteomics strategy using a standard mixture of proteins and a monkey pox virus proteome. PMID:20627868

Hugoniot and release measurements in diamond shocked up to 26 Mbar [Hugoniot and release measurements in diamond shocked up to 25 Mbar

DOE PAGES

Gregor, M. C.; Fratanduono, D. E.; McCoy, C. A.; ...

2017-04-26

The equation of state of carbon at extreme pressures is of interest to studies of planetary ice giants and white dwarfs and to inertial con nement fusion (ICF) because diamond is used as an ablator material at the National Ignition Facility (NIF). Knowledge of both the high-pressure shock and release responses of diamond are needed to accurately model an ICF implosion and design ignition targets. This article presents Hugoniot and release data for both single-crystal diamond and the high-density carbon (HDC), comprised of nanometer-scale grains, used as a NIF ablator. Experiments were performed at the Omega Laser Facility where diamondmore » was shock-compressed to multimegabar pressures and then released into reference materials with known Hugoniots (quartz, polystyrene, silica aerogel, and liquid deuterium). Impedance matching between diamond and the standards provided the data to constrain diamond release models. Hugoniot data were obtained by impedance matching with a quartz standard and results indicate that the HDC, which is ultrananocrystalline and ~4% less dense, has a sti er Hugoniot as compared to single-crystal diamond. Accuracy of the HDC data were improved using a non-steady waves correction [D. E. Fratanduono et al., J. Appl. Phys. 116, 033517 (2014)] to determine shock velocity pro les in the opaque HDC samples.« less

Effectiveness of negative pressure wound therapy/closed incision management in the prevention of post-surgical wound complications: a systematic review and meta-analysis.

PubMed

Sandy-Hodgetts, Kylie; Watts, Robin

2015-01-01

The treatment of post-surgical wound complications, such as surgical site infections and surgical wound dehiscence, generates a significant burden for patients and healthcare systems. The effectiveness of negative pressure wound therapy has been under investigation but to date no systematic review has been published in relation to its effectiveness in the prevention of surgical wound complications. To identify the effectiveness of negative pressure wound therapy in the prevention of post-surgical wound complications in adults with a closed surgical incision compared to standard surgical dressings. Male and female adults who have had negative pressure wound therapy applied to their surgical incision following a procedure in one of the following areas: trauma, cardiothoracic, orthopedic, abdominal, or vascular surgery.The intervention of interest was the use of negative pressure wound therapy directly over an incision following a surgical procedure; the comparator was standard surgical dressings.Both experimental and epidemiological study designs, including randomized controlled trials, pseudo-randomized trials, quasi-experimental studies, before and after studies, prospective and retrospective cohort studies, case control studies, and analytical cross sectional studies were sought.The primary outcome was the occurrence of post-surgical wound infection or dehiscence as measured by the following: surgical site infections - superficial and deep; surgical wound dehiscence; wound pain; wound seroma; wound hematoma. Published and unpublished studies in English from 1990 to 2013 were identified by searching a variety of electronic databases. Reference lists of all papers selected for retrieval were then searched for additional studies. Papers selected for retrieval were assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument. Data were extracted from the included papers using a standardized data extraction tool from the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument. In addition to study results, the data extracted included details of the study population, setting, intervention and author's conclusion. Where appropriate, data were pooled using Comprehensive Meta-Analysis software. Meta-analyses were performed for three outcomes. In cases of heterogeneity between studies a narrative summary of results was undertaken. Eight studies were included in the review. Meta-analyses revealed a statistically significant difference in favor of the use of negative pressure wound therapy as compared to standard surgical dressings was found for surgical site infections. Conflicting results were found for wound dehiscence and seroma. Given the small number of studies, mostly retrospective comparative cohort in design, no definitive conclusions can be reached as to the effectiveness of the use of negative pressure wound therapy in the prevention of surgical wound complications. However, there was a demonstrated association between the use of negative pressure wound therapy and reduction in surgical site infection. Negative pressure wound therapy in preference to standard postoperative dressings, for example dry gauze, may be considered for closed surgical incisions in adults assessed as high-risk for surgical site infections. The focus of further research on this topic should be level one studies (randomized controlled trials) on patients identified as 'at risk' in the preoperative period.

Pain management after laparoscopic cholecystectomy-a randomized prospective trial of low pressure and standard pressure pneumoperitoneum.

PubMed

Singla, Sanjeev; Mittal, Geeta; Raghav; Mittal, Rajinder K

2014-02-01

Abdominal pain and shoulder tip pain after laparoscopic cholecystectomy are distressing for the patient. Various causes of this pain are peritoneal stretching and diaphragmatic irritation by high intra-abdominal pressure caused by pneumoperitoneum . We designed a study to compare the post operative pain after laparoscopic cholecystectomy at low pressure (7-8 mm of Hg) and standard pressure technique (12-14 mm of Hg). Aim : To compare the effect of low pressure and standard pressure pneumoperitoneum in post laparoscopic cholecystectomy pain . Further to study the safety of low pressure pneumoperitoneum in laparoscopic cholecystectomy. A prospective randomised double blind study. A prospective randomised double blind study was done in 100 ASA grade I & II patients. They were divided into two groups -50 each. Group A patients underwent laparoscopic cholecystectomy with low pressure pneumoperitoneum (7-8 mm Hg) while group B underwent laparoscopic cholecystectomy with standard pressure pneumoperitoneum (12-13 mm Hg). Both the groups were compared for pain intensity, analgesic requirement and complications. Demographic data and intraoperative complications were analysed using chi-square test. Frequency of pain, intensity of pain and analgesics consumption was compared by applying ANOVA test. Post-operative pain score was significantly less in low pressure group as compared to standard pressure group. Number of patients requiring rescue analgesic doses was more in standard pressure group . This was statistically significant. Also total analgesic consumption was more in standard pressure group. There was no difference in intraoperative complications. This study demonstrates the use of simple expedient of reducing the pressure of pneumoperitoneum to 8 mm results in reduction in both intensity and frequency of post-operative pain and hence early recovery and better outcome.This study also shows that low pressure technique is safe with comparable rate of intraoperative complications.

[Mobile Health: IEEE Standard for Wearable Cuffless Blood Pressure Measuring Devices].

PubMed

Zhou, Xia; Wu, Wenli; Bao, Shudi

2015-07-01

IEEE Std 1708-2014 breaks through the traditional standards of cuff based blood pressure measuring devices and establishes a normative definition of wearable cuffless blood pressure measuring devices and the objective performance evaluation of this kind of devices. This study firstly introduces the background of the new standard. Then, the standard details will be described, and the impact of cuffless blood pressure measuring devices with the new standard on manufacturers and end users will be addressed.

Determination of Water Vapor Pressure Over Corrosive Chemicals Versus Temperature Using Raman Spectroscopy as Exemplified with 85.5% Phosphoric Acid.

PubMed

Rodier, Marion; Li, Qingfeng; Berg, Rolf Willestofte; Bjerrum, Niels Janniksen

2016-07-01

A method to determine the water vapor pressure over a corrosive substance was developed and tested with 85.5 ± 0.4% phosphoric acid. The water vapor pressure was obtained at a range of temperatures from ∼25 ℃ to ∼200 ℃ using Raman spectrometry. The acid was placed in an ampoule and sealed with a reference gas (either hydrogen or methane) at a known pressure (typically ∼0.5 bar). By comparing the Raman signals from the water vapor and the references, the water pressure was determined as a function of temperature. A considerable amount of data on the vapor pressure of phosphoric acid are available in the literature, to which our results could successfully be compared. A record value of the vapor pressure, 3.40 bar, was determined at 210 ℃. The method required a determination of the precise Raman scattering ratios between the substance, water, and the used reference gas, hydrogen or methane. In our case the scattering ratios between water and reference ν1 Q-branches were found to be 1.20 ± 0.03 and 0.40 ± 0.02 for H2 and CH4, respectively. © The Author(s) 2016.

Pressure standards and sensors up to 3 GPa, actual state and development trends

NASA Astrophysics Data System (ADS)

Wisniewski, Roland; Molinar, Gianfranco

1999-04-01

Metrological problems connected with pressure standards and sensors up to 3 GPa as an introduction to the pressure measurements in the so-called “GIGAPASCAL REGION”, 1-100 GPa, are discussed. Re-examination of Bi I-Bi II phase transition pressure as a fixed point of the International Practical Pressure Scale and correction of the NaCl Pressure Scale is proposed. Well-established sensors as candidates for secondary pressure standards up to 3 GPa are briefly presented.

40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

Code of Federal Regulations, 2010 CFR

2010-07-01

... gas/vapor service. 265.1054 Section 265.1054 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... TREATMENT, STORAGE, AND DISPOSAL FACILITIES Air Emission Standards for Equipment Leaks § 265.1054 Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief...

Eddy-Current Reference Standard

NASA Technical Reports Server (NTRS)

Ambrose, H. H., Jr.

1985-01-01

Magnetic properties of metallic reference standards duplicated and stabilized for eddy-current coil measurements over long times. Concept uses precisely machined notched samples of known annealed materials as reference standards.

Pressure-Volume-Temperature (PVT) Gauging of an Isothermal Cryogenic Propellant Tank Pressurized with Gaseous Helium

NASA Technical Reports Server (NTRS)

VanDresar, Neil T.; Zimmerli, Gregory A.

2014-01-01

Results are presented for pressure-volume-temperature (PVT) gauging of a liquid oxygen/liquid nitrogen tank pressurized with gaseous helium that was supplied by a high-pressure cryogenic tank simulating a cold helium supply bottle on a spacecraft. The fluid inside the test tank was kept isothermal by frequent operation of a liquid circulation pump and spray system, and the propellant tank was suspended from load cells to obtain a high-accuracy reference standard for the gauging measurements. Liquid quantity gauging errors of less than 2 percent of the tank volume were obtained when quasi-steady-state conditions existed in the propellant and helium supply tanks. Accurate gauging required careful attention to, and corrections for, second-order effects of helium solubility in the liquid propellant plus differences in the propellant/helium composition and temperature in the various plumbing lines attached to the tanks. On the basis of results from a helium solubility test, a model was developed to predict the amount of helium dissolved in the liquid as a function of cumulative pump operation time. Use of this model allowed correction of the basic PVT gauging calculations and attainment of the reported gauging accuracy. This helium solubility model is system specific, but it may be adaptable to other hardware systems.

Yeast and mammalian metabolism continuous monitoring by using pressure recording as an assessment technique for xenobiotic agent effects

NASA Astrophysics Data System (ADS)

Milani, Marziale; Ballerini, Monica; Ferraro, Lorenzo; Marelli, E.; Mazza, Francesca; Zabeo, Matteo

2002-06-01

Our work is devoted to the study of Saccharomyces cerevisiae and human lymphocytes cellular metabolism in order to develop a reference model to assess biological systems responses to chemical or physical agents exposure. CO2 variations inside test-tubes are measured by differential pressure sensors; pressure values are subsequently converted in voltage. The system allows to test up to 16 samples at the same time. Sampling manages up to 100 acquisitions per second. Values are recorded by a data acquisition card connected to a computer. This procedure leads to a standard curve (pressure variation versus time), typical of the cellular line, that describe cellular metabolism. The longest time lapse used is of 170 h. Different phases appear in this curve: an initial growth up to a maximum, followed by a decrement that leads to a typical depression (pressure value inside the test-tubes is lower than the initial one) after about 35 h from the beginning of yeast cells. The curve is reproducible within an experimental error of 4%. The analysis of many samples and the low cost of the devices allow a good statistical significance of the data. In particular as a test we will compare two sterilizing agents effects: UV radiation and amuchina.

Rabies vaccine standards: comparison of the 5th and 6th WHO international reference standards to the USDA veterinary reference standard.

PubMed

Hermann, J; Fry, A; Reising, M; Patterson, P; Siev, D; Gatewood, D

2012-11-06

Ensuring rabies vaccines are potent and effective is paramount in preventing transmission of this deadly disease and safeguarding public health. Efficacy of human and veterinary vaccines is ensured by evaluating relative potency estimates of the vaccine compared to a rabies reference standard using the National Institutes of Health (NIH) test. Reference vaccines are based on the International Standard for Rabies Vaccine provided by the World Health Organization (WHO). A comparison study was conducted to determine the relative potency of the 5th WHO, 6th WHO, and United States Department of Agriculture's (USDA) 08-14 reference standards using the NIH test. Results from the study demonstrate that the 6th WHO reference standard is approximately twice as potent as the 5th WHO reference when reconstituted to contain 1 IU per ml. Based on these results, the Center for Veterinary Biologics (CVB) doubled the reconstitution volume of USDA veterinary reference 08-14 from 13 ml to 26 ml, for an initial use dilution of 0.7 IU per ml for use by veterinary biologics manufacturers in the NIH test. This study emphasizes the importance of reference standard calibration for use in the National Institutes of Health test. Published by Elsevier Ltd.

Signal processing for ION mobility spectrometers

NASA Technical Reports Server (NTRS)

Taylor, S.; Hinton, M.; Turner, R.

1995-01-01

Signal processing techniques for systems based upon Ion Mobility Spectrometry will be discussed in the light of 10 years of experience in the design of real-time IMS. Among the topics to be covered are compensation techniques for variations in the number density of the gas - the use of an internal standard (a reference peak) or pressure and temperature sensors. Sources of noise and methods for noise reduction will be discussed together with resolution limitations and the ability of deconvolution techniques to improve resolving power. The use of neural networks (either by themselves or as a component part of a processing system) will be reviewed.

Study of Noise-Certification Standards for Aircraft Engines. Volume 2. Procedures for Measuring Far Field Sound Pressure Levels around an Outdoor Jet-Engine Test Stand.

DTIC Science & Technology

1983-06-01

60 References ........................................................... 79 AccesSqlon For NTIS rFA&I r"!’ TAU U: .,P Dist r A. -. S iv...separate exhaust nozzles for discharge of fan and turbine exhaust flows (e.g., JT15D, TFE731 , ALF-502, CF34, JT3D, CFM56, RB.211, CF6, JT9D, and PW2037...minimum radial distance from the effective source of sound at 40 Hz should then be approxi- mately 69 m. At 60 Hz, the minimum radial distance should be

A Integrated Circuit for a Biomedical Capacitive Pressure Transducer

NASA Astrophysics Data System (ADS)

Smith, Michael John Sebastian

Medical research has an urgent need for a small, accurate, stable, low-power, biocompatible and inexpensive pressure sensor with a zero to full-scale range of 0-300 mmHg. An integrated circuit (IC) for use with a capacitive pressure transducer was designed, built and tested. The random pressure measurement error due to resolution and non-linearity is (+OR-)0.4 mmHg (at mid-range with a full -scale of 300 mmHg). The long-term systematic error due to falling battery voltage is (+OR-)0.6 mmHg. These figures were calculated from measurements of temperature, supply dependence and non-linearity on completed integrated circuits. The sensor IC allows measurement of temperature to (+OR-)0.1(DEGREES)C to allow for temperature compensation of the transducer. Novel micropower circuit design of the system components enabled these levels of accuracy to be reached. Capacitance is measured by a new ratiometric scheme employing an on -chip reference capacitor. This method greatly reduces the effects of voltage supply, temperature and manufacturing variations on the sensor circuit performance. The limits on performance of the bandgap reference circuit fabricated with a standard bipolar process using ion-implanted resistors were determined. Measurements confirm the limits of temperature stability as approximately (+OR-)300 ppm/(DEGREES)C. An exact analytical expression for the period of the Schmitt trigger oscillator, accounting for non-constant capacitor charging current, was formulated. Experiments to test agreement with theory showed that prediction of the oscillator period was very accurate. The interaction of fundamental and practical limits on the scaling of the transducer size was investigated including a correction to previous theoretical analysis of jitter in an RC oscillator. An areal reduction of 4 times should be achievable.

Composite Overwrapped Pressure Vessels, A Primer

NASA Technical Reports Server (NTRS)

McLaughlan, Pat B.; Forth, Scott C.; Grimes-Ledesma, Lorie R.

2011-01-01

Due to the extensive amount of detailed information that has been published on composite overwrapped pressure vessels (COPVs), this document has been written to serve as a primer for those who desire an elementary knowledge of COPVs and the factors affecting composite safety. In this application, the word "composite" simply refers to a matrix of continuous fibers contained within a resin and wrapped over a pressure barrier to form a vessel for gas or liquid containment. COPVs are currently used at NASA to contain high pressure fluids in propulsion, science experiments, and life support applications. They have a significant weight advantage over all metal vessels but require unique design, manufacturing, and test requirements. COPVs also involve a much more complex mechanical understanding due to the interplay between the composite overwrap and the inner liner. A metallic liner is typically used in a COPV as a fluid permeation barrier. The liner design concepts and requirements have been borrowed from all-metal vessels. However, application of metallic vessel design standards to a very thin liner is not straightforward. Different failure modes exist for COPVs than for all-metal vessels, and understanding of these failure modes is at a much more rudimentary level than for metal vessels.

Calibrating/testing meters in hot water test bench VM7

NASA Astrophysics Data System (ADS)

Kling, E.; Stolt, K.; Lau, P.; Mattiasson, K.

A Hot Water Test Bench, VM7, has been developed and constructed for the calibration and testing of volume and flowmeters, in a project at the National Volume Measurement Laboratory at the Swedish National Testing and Research Institute. The intended area of use includes use as a reference at audit measurements, e.g. for accredited laboratories, calibration of meters for the industry and for the testing of hot water meters. The objective of the project, which was initiated in 1989, was to design equipment with stable flow and with a minimal temperature drop even at very low flow rates. The principle of the design is a closed system with two pressure tanks at different pressures. The water is led from the high pressure tank through the test object and the volume standard, in the form of master meters or a piston prover alternatively, to the low pressure tank. Calibrations/tests are made comparing the indication of the test object to that of master meters covering the current flow rate. These are, in the same test cycle, calibrated to the piston prover. Alternatively, the test object can be calibrated directly to the piston prover.

Calibration of the pressure sensitivity of microphones by a free-field method at frequencies up to 80 khz.

PubMed

Zuckerwar, Allan J; Herring, G C; Elbing, Brian R

2006-01-01

A free-field (FF) substitution method for calibrating the pressure sensitivity of microphones at frequencies up to 80 kHz is demonstrated with both grazing and normal-incidence geometries. The substitution-based method, as opposed to a simultaneous method, avoids problems associated with the nonuniformity of the sound field and, as applied here, uses a 1/4-in. air-condenser pressure microphone as a known reference. Best results were obtained with a centrifugal fan, which is used as a random, broadband sound source. A broadband source minimizes reflection-related interferences that can plague FF measurements. Calibrations were performed on 1/4-in. FF air-condenser, electret, and microelectromechanical systems (MEMS) microphones in an anechoic chamber. The uncertainty of this FF method is estimated by comparing the pressure sensitivity of an air-condenser FF microphone, as derived from the FF measurement, with that of an electrostatic actuator calibration. The root-mean-square difference is found to be +/- 0.3 dB over the range 1-80 kHz, and the combined standard uncertainty of the FF method, including other significant contributions, is +/- 0.41 dB.

A pressure-affected headspace-gas chromatography method for determining calcium carbonate content in paper sample.

PubMed

Dai, Yi; Yu, Zhen-Hua; Zhan, Jian-Bo; Chai, Xin-Sheng; Zhang, Shu-Xin; Xie, Wei-Qi; He, Liang

2017-07-21

The present work reports on the development of a pressure-affected based headspace (HS) analytical technique for the determination of calcium carbonate content in paper samples. By the acidification, the carbonate in the sample was converted to CO 2 and released into the headspace of a closed vial and then measured by gas chromatography (GC). When the amount of carbonate in the sample is significant, the pressure created by the CO 2 affects the accuracy of the method. However, the pressure also causes a change in the O 2 signal in the HS-GC measurement, which is a change that can be used as an indirect measure of the carbonate in the sample. The results show that the present method has a good precision (the relative standard deviation<2.32%), and good accuracy (the relative differences compared to a reference method was<5.76%). Coupled with the fact that the method is simple, rapid, and accurate, it is suitable for a variety of applications that call for the analysis of high carbonate content in paper samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Direct calibration of a reference standard against the air kerma strength primary standard, at 192Ir HDR energy.

PubMed

Rajan, K N Govinda; Selvam, T Palani; Bhatt, B C; Vijayam, M; Patki, V S; Vinatha; Pendse, A M; Kannan, V

2002-04-07

The primary standard of low air kerma rate sources or beams, maintained at the Radiological Standards Laboratory (RSL) of the Bhabha Atomic Research Centre (BARC), is a 60 cm3 spherical graphite ionization chamber. A 192Ir HDR source was standardized at the hospital site in units of air kerma strength (AKS) using this primary standard. A 400 cm3 bakelite chamber, functioning as a reference standard at the RSL for a long period, at low air kerma rates (compared to external beam dose rates), was calibrated against the primary standard. It was seen that the primary standard and the reference standard, both being of low Z, showed roughly the same scatter response and yielded the same calibration factor for the 400 cm3 reference chamber, with or without room scatter. However, any likelihood of change in the reference chamber calibration factor would necessitate the re-transport of the primary standard to the hospital site for re-calibration. Frequent transport of the primary standard can affect the long-term stability of the primary standard, due to its movement or other extraneous causes. The calibration of the reference standard against the primary standard at the RSL, for an industrial type 192Ir source maintained at the laboratory, showed excellent agreement with the hospital calibration, making it possible to check the reference chamber calibration at RSL itself. Further calibration procedures have been developed to offer traceable calibration of the hospital well ionization chambers.

Development and Evaluation of Reference Standards for Image-based Telemedicine Diagnosis and Clinical Research Studies in Ophthalmology

PubMed Central

Ryan, Michael C.; Ostmo, Susan; Jonas, Karyn; Berrocal, Audina; Drenser, Kimberly; Horowitz, Jason; Lee, Thomas C.; Simmons, Charles; Martinez-Castellanos, Maria-Ana; Chan, R.V. Paul; Chiang, Michael F.

2014-01-01

Information systems managing image-based data for telemedicine or clinical research applications require a reference standard representing the correct diagnosis. Accurate reference standards are difficult to establish because of imperfect agreement among physicians, and discrepancies between clinical vs. image-based diagnosis. This study is designed to describe the development and evaluation of reference standards for image-based diagnosis, which combine diagnostic impressions of multiple image readers with the actual clinical diagnoses. We show that agreement between image reading and clinical examinations was imperfect (689 [32%] discrepancies in 2148 image readings), as was inter-reader agreement (kappa 0.490-0.652). This was improved by establishing an image-based reference standard defined as the majority diagnosis given by three readers (13% discrepancies with image readers). It was further improved by establishing an overall reference standard that incorporated the clinical diagnosis (10% discrepancies with image readers). These principles of establishing reference standards may be applied to improve robustness of real-world systems supporting image-based diagnosis. PMID:25954463

Selection of reference standard during method development using the analytical hierarchy process.

PubMed

Sun, Wan-yang; Tong, Ling; Li, Dong-xiang; Huang, Jing-yi; Zhou, Shui-ping; Sun, Henry; Bi, Kai-shun

2015-03-25

Reference standard is critical for ensuring reliable and accurate method performance. One important issue is how to select the ideal one from the alternatives. Unlike the optimization of parameters, the criteria of the reference standard are always immeasurable. The aim of this paper is to recommend a quantitative approach for the selection of reference standard during method development based on the analytical hierarchy process (AHP) as a decision-making tool. Six alternative single reference standards were assessed in quantitative analysis of six phenolic acids from Salvia Miltiorrhiza and its preparations by using ultra-performance liquid chromatography. The AHP model simultaneously considered six criteria related to reference standard characteristics and method performance, containing feasibility to obtain, abundance in samples, chemical stability, accuracy, precision and robustness. The priority of each alternative was calculated using standard AHP analysis method. The results showed that protocatechuic aldehyde is the ideal reference standard, and rosmarinic acid is about 79.8% ability as the second choice. The determination results successfully verified the evaluation ability of this model. The AHP allowed us comprehensive considering the benefits and risks of the alternatives. It was an effective and practical tool for optimization of reference standards during method development. Copyright © 2015 Elsevier B.V. All rights reserved.

Validation of the custo screen pediatric blood pressure monitor according to the European Society of Hypertension International Protocol revision 2010.

PubMed

Beime, Beate; Deutsch, Cornelia; Krüger, Ralf; Wolf, Andreas; Müller, Peter; Hammel, Gertrud; Bramlage, Peter

2017-05-01

The purpose of the study was to validate the ambulatory blood pressure monitoring (ABPM) device custo screen pediatric in children aged 3 to 12 years according to the International Protocol of the European Society of Hypertension (ESH-IP revision 2010). Thirty-three children were included and systolic and diastolic blood pressure measurements were performed according to the ESH-IP. The protocol was modified for children considering data from the German Health Interview and Examination Survey for Children and Adolescents (KIGGS). The custo screen pediatric met all the requirements of the ESH-IP. The mean difference between the test device and the reference was -1.4 ± 3.0 mmHg for systolic blood pressure (SBP) and -0.7 ± 3.2 mmHg for diastolic blood pressure (DBP). For SBP and DBP, all 99 measurements were within the absolute difference of 10 mmHg between the test device and the reference. As to part 2 of the protocol, for DBP in all subjects, two out of three measurements were within 5 mmHg between the device and the standard, whereas for SBP in 32 of 33 subjects, two out of three measurements were within this range. The custo screen pediatric met all criteria of the ESH-IP review 2010, modified for children from 3 to about 12 years, and can be recommended for ABPM in children. What is Known: • Validation of blood pressure measuring devices is essential to provide patients with an accurate blood pressure measuring device. • The majority of devices has not been validated in children. What is New: • Prior to the present validation, study protocol adjustments of ESH-IP review 2010 for children were defined according to German Health Interview and Examination Survey for Children and Adolescents 2013 (KIGGS). • The custo screen pediatric test device met all criteria of ESH-IP revision 2010, modified for children, and can be recommended for ABPM in children aged 3 to about 12 years.

The relationship between orthostatic hypotension and falling in older adults.

PubMed

Shaw, Brett H; Claydon, Victoria E

2014-02-01

Falls are devastating events and are the largest contributor towards injury-related hospitalization of older adults. Orthostatic hypotension (OH) represents an intrinsic risk factor for falls in older adults. OH refers to a significant decrease in blood pressure upon assuming an upright posture. Declines in blood pressure can reduce cerebral perfusion; this can impair consciousness, lead to dizziness, and increase the likelihood of a fall. Although theoretical mechanisms linking OH and falls exist, the magnitude of the association remains poorly characterized, possibly because of methodological differences between previous studies. The use of non-invasive beat-to-beat blood pressure monitoring has altered the way in which OH is now defined, and represents a substantial improvement for detecting OH that was previously unavailable in many studies. Additionally, there is a lack of consistency and standardization of orthostatic assessments and analysis techniques for interpreting blood pressure data. This review explores the previous literature examining the relationship between OH and falls. We highlight the impact of broadening the timing, degree, and overall duration of blood pressure measurements on the detection of OH. We discuss the types of orthostatic stress assessments currently used to evaluate OH and the various techniques capable of measuring these often transient blood pressure changes. Overall, we identify future solutions that may better clarify the relationship between OH and falling risk in order to gain a more precise understanding of potential mechanisms for falls in older adults.

78 FR 41369 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-10

... Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania: Preliminary Results of..., line and pressure pipe (small diameter seamless pipe) from Romania. The period of review (POR) is... and Alloy Seamless Standard, Line and Pressure Pipe from Romania,'' dated concurrently with this...

[How does central cornea thickness influence intraocular pressure during applanation and contour tonometry?].

PubMed

Schwenteck, T; Knappe, M; Moros, I

2012-09-01

Golmann applanation tonometry represents a well-established procedure for measuring intraocular pressure (IOP). This implies the necessity of an accurate measurement of IOP with the reference tonometer. One example is the contour tonometer Pascal with a measuring probe, adapted to the cornea geometry, for measuring the IOP and the ocular pulse amplitude. There is controversy of how strongly corneal thickness affects the measurement of IOP. We thus analysed, for a number of eyes, the correlation of IOP, as measured by two types of applanation tonometers and one contour tonometer and the central corneal thickness. In all 158 patient eyes were investigated in a clinical comparison of applanation tonometers AT 870 and Ocuton-A. The study was performed by a trained ophthalmologist and the comparison was in accordance with international standard ISO 8612. In addition, the corneal thickness in the vertex was repeatedly determined using an Oculus Pentacam. The potential effect of central corneal thickness on the IOP as measured by the mentioned tonometers was statistically evaluated by rank correlation analysis. We found that the measured IOP values for the three investigated tonometers were not normally distributed. The central corneal thickness values, in contrast, measured on 158 eyes by means of an ultrasound pachymeter and additionally on 235 eyes by the Pentacam, obeyed a Gaussian distribution. For the correlation analysis of both parameters the Spearman linear rank correlation coefficient (r) was considered. We found a very weak (|r| < 0.2) correlation between central corneal thickness and IOP for all 3 tonometers. The softness of the correlation is also illustrated by a large standard deviation of the regression line. A comparison of the different devices for corneal-thickness measurements shows less variance and a smaller variation coefficient when the ultrasoundpachymeter AL-1000 is used. The measured values for IOP are only very weakly correlated to the central corneal thickness. For the 3 tonometer types studied there is no need to correct the indicated pressure values according to the central corneal thickness of the investigated eye. Clinical comparisons according to the ISO 8612 standard between a tonometer under test and a reference Goldmann applanation tonometer are always a time-consuming procedure. Additional measures to determine the central corneal thickness of every investigated eyes are dispensable. © Georg Thieme Verlag KG Stuttgart · New York.

Implanted Blood-Pressure-Measuring Device

NASA Technical Reports Server (NTRS)

Fischell, Robert E.

1988-01-01

Arterial pressure compared with ambient bodily-fluid pressure. Implanted apparatus, capable of measuring blood pressure of patient, includes differential-pressure transducer connected to pressure sensor positioned in major artery. Electrical signal is function of differential pressure between blood-pressure sensor and reference-pressure sensor transmitted through skin of patient to recorder or indicator.

Assessing the impact of non-tidal atmospheric loading on a Kalman filter-based terrestrial reference frame

NASA Astrophysics Data System (ADS)

Abbondanza, Claudio; Altamimi, Zuheir; Chin, Toshio; Collilieux, Xavier; Dach, Rolf; Gross, Richard; Heflin, Michael; König, Rolf; Lemoine, Frank; Macmillan, Dan; Parker, Jay; van Dam, Tonie; Wu, Xiaoping

2014-05-01

The International Terrestrial Reference Frame (ITRF) adopts a piece-wise linear model to parameterize regularized station positions and velocities. The space-geodetic (SG) solutions from VLBI, SLR, GPS and DORIS used as input in the ITRF combination process account for tidal loading deformations, but ignore the non-tidal part. As a result, the non-linear signal observed in the time series of SG-derived station positions in part reflects non-tidal loading displacements not introduced in the SG data reduction. In this analysis, we assess the impact of non-tidal atmospheric loading (NTAL) corrections on the TRF computation. Focusing on the a-posteriori approach, (i) the NTAL model derived from the National Centre for Environmental Prediction (NCEP) surface pressure is removed from the SINEX files of the SG solutions used as inputs to the TRF determinations; (ii) adopting a Kalman-filter based approach, two distinct linear TRFs are estimated combining the 4 SG solutions with (corrected TRF solution) and without the NTAL displacements (standard TRF solution). Linear fits (offset and atmospheric velocity) of the NTAL displacements removed during step (i) are estimated accounting for the station position discontinuities introduced in the SG solutions and adopting different weighting strategies. The NTAL-derived (atmospheric) velocity fields are compared to those obtained from the TRF reductions during step (ii). The consistency between the atmospheric and the TRF-derived velocity fields is examined. We show how the presence of station position discontinuities in SG solutions degrades the agreement between the velocity fields and compare the effect of different weighting structure adopted while estimating the linear fits to the NTAL displacements. Finally, we evaluate the effect of restoring the atmospheric velocities determined through the linear fits of the NTAL displacements to the single-technique linear reference frames obtained by stacking the standard SG SINEX files. Differences between the velocity fields obtained restoring the NTAL displacements and the standard stacked linear reference frames are discussed.

15 CFR 200.105 - Standard reference data.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., PROCEDURES, AND FEES § 200.105 Standard reference data. Data on the physical and chemical properties of the... application in research, development, engineering design, and commerce. The Office of Standard Reference Data... Physical and Chemical Reference Data, published jointly with the American Chemical Society and the American...

15 CFR 200.105 - Standard reference data.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., PROCEDURES, AND FEES § 200.105 Standard reference data. Data on the physical and chemical properties of the... application in research, development, engineering design, and commerce. The Office of Standard Reference Data... Physical and Chemical Reference Data, published jointly with the American Chemical Society and the American...

15 CFR 200.105 - Standard reference data.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., PROCEDURES, AND FEES § 200.105 Standard reference data. Data on the physical and chemical properties of the... application in research, development, engineering design, and commerce. The Office of Standard Reference Data... Physical and Chemical Reference Data, published jointly with the American Chemical Society and the American...

15 CFR 200.105 - Standard reference data.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., PROCEDURES, AND FEES § 200.105 Standard reference data. Data on the physical and chemical properties of the... application in research, development, engineering design, and commerce. The Office of Standard Reference Data... Physical and Chemical Reference Data, published jointly with the American Chemical Society and the American...

Accuracy and Precision in the Southern Hemisphere Additional Ozonesondes (SHADOZ) Dataset 1998-2000 in Light of the JOSIE-2000 Results

NASA Technical Reports Server (NTRS)

Witte, J. C.; Thompson, A. M.; Schmidlin, F. J.; Oltmans, S. J.; McPeters, R. D.; Smit, H. G. J.

2003-01-01

A network of 12 southern hemisphere tropical and subtropical stations in the Southern Hemisphere ADditional OZonesondes (SHADOZ) project has provided over 2000 profiles of stratospheric and tropospheric ozone since 1998. Balloon-borne electrochemical concentration cell (ECC) ozonesondes are used with standard radiosondes for pressure, temperature and relative humidity measurements. The archived data are available at:http: //croc.gsfc.nasa.gov/shadoz. In Thompson et al., accuracies and imprecisions in the SHADOZ 1998- 2000 dataset were examined using ground-based instruments and the TOMS total ozone measurement (version 7) as references. Small variations in ozonesonde technique introduced possible biases from station-to-station. SHADOZ total ozone column amounts are now compared to version 8 TOMS; discrepancies between the two datasets are reduced 2\\% on average. An evaluation of ozone variations among the stations is made using the results of a series of chamber simulations of ozone launches (JOSIE-2000, Juelich Ozonesonde Intercomparison Experiment) in which a standard reference ozone instrument was employed with the various sonde techniques used in SHADOZ. A number of variations in SHADOZ ozone data are explained when differences in solution strength, data processing and instrument type (manufacturer) are taken into account.

A method to enhance the measurement accuracy of Raman shift based on high precision calibration technique

NASA Astrophysics Data System (ADS)

Ding, Xiang; Li, Fei; Zhang, Jiyan; Liu, Wenli

2016-10-01

Raman spectrometers are usually calibrated periodically to ensure their measurement accuracy of Raman shift. A combination of a piece of monocrystalline silicon chip and a low pressure discharge lamp is proposed as a candidate for the reference standard of Raman shift. A high precision calibration technique is developed to accurately determine the standard value of the silicon's Raman shift around 520cm-1. The technique is described and illustrated by measuring a piece of silicon chip against three atomic spectral lines of a neon lamp. A commercial Raman spectrometer is employed and its error characteristics of Raman shift are investigated. Error sources are evaluated based on theoretical analysis and experiments, including the sample factor, the instrumental factor, the laser factor and random factors. Experimental results show that the expanded uncertainty of the silicon's Raman shift around 520cm-1 can acheive 0.3 cm-1 (k=2), which is more accurate than most of currently used reference materials. The results are validated by comparison measurement between three Raman spectrometers. It is proved that the technique can remarkably enhance the accuracy of Raman shift, making it possible to use the silicon and the lamp to calibrate Raman spectrometers.

Final report on the supplementary comparison, EURAMET.M.P-S7 (EURAMET project 1040) in the pressure range from 1.10-4 Pa to 0.9 Pa

NASA Astrophysics Data System (ADS)

Wüthrich, C.; Alisic, S.; Bergoglio, M.; Saxholm, S.; Lefkopoulos, A.; Pražák, D.; Setina, J.

2016-01-01

Many laboratories within EURAMET started a calibration service in medium and high vacuum recently and did not have the opportunity to take part to a comparison before. In order to assess the uncertainty budget and the quality of the measurement of these laboratories, an intercomparison, EURAMET 1040 registered as EURAMET.M.P-S7, from 0.1 mPa to 0.9 Pa has been organised. The participants are the CMI (Czech republic), EIM (Greece), IMT (Slovenia), INRIM (Italy), IMBIH (Bosnia Herzegovinia) and MIKES (Finland) while METAS (Switzerland) is pilot laboratory. Three laboratories (INRIM, CMI and METAS) involved in this work have a primary definition of the pressure. Two spinning rotor gauges and a control electronic are used as transfer standard. The circulation of the transfer standard is organised as a succession of loops with a measurement by the pilot between each participant. A reference value has been determined based on a weighted mean of the results of the primary laboratories. All the participants have demonstrated their equivalence in the definition of the pressure. This comparison has been used as pilot comparison for the CCM.P-K14 project which covers the same scope with similar transfer standards. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

3013/9975 Surveillance Program Interim Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunn, K.; Hackney, B.; McClard, J.

2011-06-22

The K-Area Materials Storage (KAMS) Documented Safety Analysis (DSA) requires a surveillance program to monitor the safety performance of 3013 containers and 9975 shipping packages stored in KAMS. The SRS surveillance program [Reference 1] outlines activities for field surveillance and laboratory tests that demonstrate the packages meet the functional performance requirements described in the DSA. The SRS program also supports the complexwide Integrated Surveillance Program (ISP) [Reference 2] for 3013 containers. The purpose of this report is to provide a summary of the SRS portion of the surveillance program activities through fiscal year 2010 (FY10) and formally communicate the interpretationmore » of these results by the Surveillance Program Authority (SPA). Surveillance for the initial 3013 container random sampling of the Innocuous bin and the Pressure bin has been completed and there has been no indication of corrosion or significant pressurization. The maximum pressure observed was less than 50 psig, which is well below the design pressure of 699 psig for the 3013 container [Reference 3]. The data collected during surveillance of these bins has been evaluated by the Materials Identification and Surveillance (MIS) Working Group and no additional surveillance is necessary for these bins at least through FY13. A decision will be made whether additional surveillance of these bins is needed during future years of storage and as additional containers are generated. Based on the data collected to date, the SPA concludes that 3013 containers in these bins can continue to be safely stored in KAMS. This year, 13 destructive examinations (DE) were performed on random samples from the Pressure & Corrosion bin. To date, DE has been completed for approximately 30% of the random samples from the Pressure & Corrosion bin. In addition, DE has been performed on 6 engineering judgment (EJ) containers, for a total of 17 to date. This includes one container that exceeded the 3013 Standard moisture limit which was opened at LANL. The container pieces and an oxide sample were sent to SRNL for examination in FY11. No significant pressurization has been observed for the Pressure & Corrosion bin containers. Relatively minor corrosion has been observed on some convenience containers and the inside of two inner containers. While the limited extent of corrosion does not jeopardize the integrity of the outer 3013 containers, it does highlight the importance of continuing to perform DE and the Shelf Life program to assure that the corrosion rate is not accelerating or changing to a different corrosion mechanism (e.g., stress corrosion cracking). Statistical sampling is currently scheduled to be completed in FY17, but there is a proposed reduction of the number of DE's per year for FY11 and beyond which may delay the completion date. Since 3013 containers are stored inside 9975 containers, surveillances of 9975 containers are performed in conjunction with 3013 container surveillances. Results of 9975 container nondestructive examinations (NDEs) and DEs indicate that the containers will provide adequate protection of the 3013 containers in K-Area storage for at least 15 years [Reference 4].« less

Designing image segmentation studies: Statistical power, sample size and reference standard quality.

PubMed

Gibson, Eli; Hu, Yipeng; Huisman, Henkjan J; Barratt, Dean C

2017-12-01

Segmentation algorithms are typically evaluated by comparison to an accepted reference standard. The cost of generating accurate reference standards for medical image segmentation can be substantial. Since the study cost and the likelihood of detecting a clinically meaningful difference in accuracy both depend on the size and on the quality of the study reference standard, balancing these trade-offs supports the efficient use of research resources. In this work, we derive a statistical power calculation that enables researchers to estimate the appropriate sample size to detect clinically meaningful differences in segmentation accuracy (i.e. the proportion of voxels matching the reference standard) between two algorithms. Furthermore, we derive a formula to relate reference standard errors to their effect on the sample sizes of studies using lower-quality (but potentially more affordable and practically available) reference standards. The accuracy of the derived sample size formula was estimated through Monte Carlo simulation, demonstrating, with 95% confidence, a predicted statistical power within 4% of simulated values across a range of model parameters. This corresponds to sample size errors of less than 4 subjects and errors in the detectable accuracy difference less than 0.6%. The applicability of the formula to real-world data was assessed using bootstrap resampling simulations for pairs of algorithms from the PROMISE12 prostate MR segmentation challenge data set. The model predicted the simulated power for the majority of algorithm pairs within 4% for simulated experiments using a high-quality reference standard and within 6% for simulated experiments using a low-quality reference standard. A case study, also based on the PROMISE12 data, illustrates using the formulae to evaluate whether to use a lower-quality reference standard in a prostate segmentation study. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Simultaneous determination of nine saponins from Panax notoginseng using HPLC and pressurized liquid extraction.

PubMed

Wan, J B; Lai, C M; Li, S P; Lee, M Y; Kong, L Y; Wang, Y T

2006-04-11

A HPLC and pressurized liquid extraction (PLE) method was developed for simultaneous determination of nine saponins, including notoginsenoside R1, ginsenoside Rg1, Re, Rf, Rb1, Rc, Rb2, Rb3 and Rd in Panax notoginseng. The analysis was performed on C18 column with water-acetonitrile gradient elution and the investigated saponins were authenticated by comparing retention time and mass spectra with their reference compounds. Several methods including PLE, ultrasonication, soxhlet extraction and immersion were used for sample preparation and their extraction efficiency was compared. The results showed that PLE has the highest extraction efficiency and repeatability, which would be valuable on standardization of sample preparation for quality control of Chinese medicines. The developed HPLC and PLE is an effective approach for simultaneously quantitative determination of sapoinins in P. notoginseng, which could be used for quality control of P. notoginseng and its preparations.

Implicit Large-Eddy Simulations of Zero-Pressure Gradient, Turbulent Boundary Layer

NASA Technical Reports Server (NTRS)

Sekhar, Susheel; Mansour, Nagi N.

2015-01-01

A set of direct simulations of zero-pressure gradient, turbulent boundary layer flows are conducted using various span widths (62-630 wall units), to document their influence on the generated turbulence. The FDL3DI code that solves compressible Navier-Stokes equations using high-order compact-difference scheme and filter, with the standard recycling/rescaling method of turbulence generation, is used. Results are analyzed at two different Re values (500 and 1,400), and compared with spectral DNS data. They show that a minimum span width is required for the mere initiation of numerical turbulence. Narrower domains ((is) less than 100 w.u.) result in relaminarization. Wider spans ((is) greater than 600 w.u.) are required for the turbulent statistics to match reference DNS. The upper-wall boundary condition for this setup spawns marginal deviations in the mean velocity and Reynolds stress profiles, particularly in the buffer region.

High-Temperature Adiabatic Calorimeter for Constant-Volume Heat Capacity Measurements of Compressed Gases and Liquids

PubMed Central

Magee, Joseph W.; Deal, Renee J.; Blanco, John C.

1998-01-01

A high-temperature adiabatic calorimeter has been developed to measure the constant-volume specific heat capacities (cV) of both gases and liquids, especially fluids of interest to emerging energy technologies. The chief design feature is its nearly identical twin bomb arrangement, which allows accurate measurement of energy differences without large corrections for energy losses due to thermal radiation fluxes. Operating conditions for the calorimeter cover a range of temperatures from 250 K to 700 K and at pressures up to 20 MPa. Performance tests were made with a sample of twice-distilled water. Heat capacities for water were measured from 300 K to 420 K at pressures to 20 MPa. The measured heat capacities differed from those calculated with an independently developed standard reference formulation with a root-mean-square fractional deviation of 0.48 %. PMID:28009375

Reference Standard Test and the Diagnostic Ability of Spectral Domain Optical Coherence Tomography in Glaucoma.

PubMed

Rao, Harsha L; Yadav, Ravi K; Addepalli, Uday K; Begum, Viquar U; Senthil, Sirisha; Choudhari, Nikhil S; Garudadri, Chandra S

2015-08-01

To evaluate the relationship between the reference standard used to diagnose glaucoma and the diagnostic ability of spectral domain optical coherence tomograph (SDOCT). In a cross-sectional study, 280 eyes of 175 consecutive subjects, referred to a tertiary eye care center for glaucoma evaluation, underwent optic disc photography, visual field (VF) examination, and SDOCT examination. The cohort was divided into glaucoma and control groups based on 3 reference standards for glaucoma diagnosis: first based on the optic disc classification (179 glaucoma and 101 control eyes), second on VF classification (glaucoma hemifield test outside normal limits and pattern SD with P-value of <5%, 130 glaucoma and 150 control eyes), and third on the presence of both glaucomatous optic disc and glaucomatous VF (125 glaucoma and 155 control eyes). Relationship between the reference standards and the diagnostic parameters of SDOCT were evaluated using areas under the receiver operating characteristic curve, sensitivity, and specificity. Areas under the receiver operating characteristic curve and sensitivities of most of the SDOCT parameters obtained with the 3 reference standards (ranging from 0.74 to 0.88 and 72% to 88%, respectively) were comparable (P>0.05). However, specificities of SDOCT parameters were significantly greater (P<0.05) with optic disc classification as reference standard (74% to 88%) compared with VF classification as reference standard (57% to 74%). Diagnostic parameters of SDOCT that was significantly affected by reference standard was the specificity, which was greater with optic disc classification as the reference standard. This has to be considered when comparing the diagnostic ability of SDOCT across studies.

Pain Management after Laparoscopic Cholecystectomy-A Randomized Prospective Trial of Low Pressure and Standard Pressure Pneumoperitoneum

PubMed Central

Singla, Sanjeev; Mittal, Geeta; Raghav; Mittal, Rajinder K

2014-01-01

Background: Abdominal pain and shoulder tip pain after laparoscopic cholecystectomy are distressing for the patient. Various causes of this pain are peritoneal stretching and diaphragmatic irritation by high intra-abdominal pressure caused by pneumoperitoneum . We designed a study to compare the post operative pain after laparoscopic cholecystectomy at low pressure (7-8 mm of Hg) and standard pressure technique (12-14 mm of Hg). Aim : To compare the effect of low pressure and standard pressure pneumoperitoneum in post laparoscopic cholecystectomy pain . Further to study the safety of low pressure pneumoperitoneum in laparoscopic cholecystectomy. Settings and Design: A prospective randomised double blind study. Materials and Methods: A prospective randomised double blind study was done in 100 ASA grade I & II patients. They were divided into two groups -50 each. Group A patients underwent laparoscopic cholecystectomy with low pressure pneumoperitoneum (7-8 mm Hg) while group B underwent laparoscopic cholecystectomy with standard pressure pneumoperitoneum (12-13 mm Hg). Both the groups were compared for pain intensity, analgesic requirement and complications. Statistical Analysis: Demographic data and intraoperative complications were analysed using chi-square test. Frequency of pain, intensity of pain and analgesics consumption was compared by applying ANOVA test. Results: Post-operative pain score was significantly less in low pressure group as compared to standard pressure group. Number of patients requiring rescue analgesic doses was more in standard pressure group . This was statistically significant. Also total analgesic consumption was more in standard pressure group. There was no difference in intraoperative complications. Conclusion: This study demonstrates the use of simple expedient of reducing the pressure of pneumoperitoneum to 8 mm results in reduction in both intensity and frequency of post-operative pain and hence early recovery and better outcome.This study also shows that low pressure technique is safe with comparable rate of intraoperative complications. PMID:24701492

34 CFR 73.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 1 2011-07-01 2011-07-01 false Cross-reference to employee ethical conduct standards... of Education STANDARDS OF CONDUCT § 73.1 Cross-reference to employee ethical conduct standards and... branch-wide Standards of Ethical Conduct at 5 CFR part 2635 and to the Department of Education regulation...

34 CFR 73.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false Cross-reference to employee ethical conduct standards... of Education STANDARDS OF CONDUCT § 73.1 Cross-reference to employee ethical conduct standards and... branch-wide Standards of Ethical Conduct at 5 CFR part 2635 and to the Department of Education regulation...

34 CFR 73.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 1 2014-07-01 2014-07-01 false Cross-reference to employee ethical conduct standards... of Education STANDARDS OF CONDUCT § 73.1 Cross-reference to employee ethical conduct standards and... branch-wide Standards of Ethical Conduct at 5 CFR part 2635 and to the Department of Education regulation...

34 CFR 73.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 34 Education 1 2013-07-01 2013-07-01 false Cross-reference to employee ethical conduct standards... of Education STANDARDS OF CONDUCT § 73.1 Cross-reference to employee ethical conduct standards and... branch-wide Standards of Ethical Conduct at 5 CFR part 2635 and to the Department of Education regulation...

34 CFR 73.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 34 Education 1 2012-07-01 2012-07-01 false Cross-reference to employee ethical conduct standards... of Education STANDARDS OF CONDUCT § 73.1 Cross-reference to employee ethical conduct standards and... branch-wide Standards of Ethical Conduct at 5 CFR part 2635 and to the Department of Education regulation...

Focus control system for stretched-membrane mirror module

DOEpatents

Butler, B.L.; Beninga, K.J.

1991-05-21

A focus control system dynamically sets and controls the focal length of a reflective membrane supported between a perimeter frame. A rear membrane is also supported between the perimeter frame rearward and spaced apart from a back side of the reflective membrane. The space between the membranes defines a plenum space into which a mass of gas at a first pressure is inserted. The pressure differential between the first pressure and an external pressure, such as the atmospheric pressure, causes the reflective membrane to assume a first curvature relative to a reference plane associated with the perimeter frame. This curvature defines the focal length of the reflective membrane. The focal length is dynamically controlled by changing the volume of the plenum space, thereby changing the first pressure. The system can be used to change or maintain the pressure differential and hence the front membrane curvature. The plenum volume is changed by pushing or pulling on a central section of the rear membrane using a suitable actuator. Sensing means continuously sense the location of the reflective membrane relative to the reference plane. This sensed position is compared to a reference position, and a resulting error signal, comprising the difference between the sensed position and reference position, drives the actuator in a direction to minimize the difference. A vent value compensates for temperature changes or leaks in the closed volume by allowing the pressure differential to be adjusted as required to center the working range of the actuator about the desired focal length. 13 figures.

Focus control system for stretched-membrane mirror module

DOEpatents

Butler, Barry L.; Beninga, Kelly J.

1991-01-01

A focus control system dynamically sets and controls the focal length of a reflective membrane supported between a perimeter frame. A rear membrane is also supported between the perimeter frame rearward and spaced apart from a back side of the reflective membrane. The space between the membranes defines a plenum space into which a mass of gas at a first pressure is inserted. The pressure differential between the first pressure and an external pressure, such as the atmospheric pressure, causes the reflective membrane to assume a first curvature relative to a reference plane associated with the perimeter frame. This curvature defines the focal length of the reflective membrane. The focal length is dynamically controlled by changing the volume of the plenum space, thereby changing the first pressure. The system can be used to change or maintain the pressure differential and hence the front membrane curvature. The plenum volume is changed by pushing or pulling on a central section of the rear membrane using a suitable actuator. Sensing means continuously sense the location of the reflective membrane relative to the reference plane. This sensed position is compared to a reference position, and a resulting error signal, comprising the difference between the sensed position and reference position, drives the actuator in a direction to minimize the difference. A vent value compensates for temperature changes or leaks in the closed volume by allowing the pressure differential to be adjusted as required to center the working range of the actuator about the desired focal length.

Doxycycline concentration over time after storage in a compounded veterinary preparation.

PubMed

Papich, Mark G; Davidson, Gigi S; Fortier, Lisa A

2013-06-15

To determine the concentration of doxycycline compounded from doxycycline hyclate tablets into liquid formulations for oral administration in veterinary species and stored for 28 days. Evaluation study. Doxycycline hyclate tablets (100 mg) crushed and mixed with a 50:50 mixture of syrup and suspension vehicles for oral administration to produce 3 batches each of 2 doxycycline formulations: 33.3 and 166.7 mg/mL. Formulations were stored, protected from light, at room temperature (22° to 26°C [71.6° to 78.8°F]) and at a controlled cold temperature (refrigerated 2° to 8°C [35.6° to 46.4°F]). Doxycycline was extracted from the formulations, and concentration was measured by high-pressure liquid chromatography on days 0 (date of preparation), 1, 4, 7, 14, 21, and 28. Concentrations were compared with those of a US Pharmacopeial Convention reference standard. Formulation quality at each point was also assessed through color change, formulation consistency, and suspension uniformity. On days 0, 1, 4, and 7, the concentration of each formulation was within 90% to 110% of the reference standard (range, 93% to 109%), which was deemed acceptable. However, doxycycline concentrations had decreased dramatically by day 14 and remained low for the duration of the study period. Doxycycline concentrations on days 14, 21, and 28 were all < 20% (range, 14% to 18%) of the reference standard, and the quality of the formulations decreased as well. No effect of storage temperatures on doxycycline concentration was identified. The concentration of doxycycline, compounded from commercial tablets in the vehicles evaluated to yield doses of 33.3 and 166.7 mg/mL, cannot be assured beyond 7 days.

7 CFR 1728.97 - Incorporation by reference of electric standards and specifications.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 11 2014-01-01 2014-01-01 false Incorporation by reference of electric standards and...) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE ELECTRIC STANDARDS AND SPECIFICATIONS FOR MATERIALS AND CONSTRUCTION § 1728.97 Incorporation by reference of electric standards and specifications. The...

7 CFR 1728.97 - Incorporation by reference of electric standards and specifications.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 11 2012-01-01 2012-01-01 false Incorporation by reference of electric standards and...) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE ELECTRIC STANDARDS AND SPECIFICATIONS FOR MATERIALS AND CONSTRUCTION § 1728.97 Incorporation by reference of electric standards and specifications. The...

Method performance and multi-laboratory assessment of a normal phase high pressure liquid chromatography-fluorescence detection method for the quantitation of flavanols and procyanidins in cocoa and chocolate containing samples.

PubMed

Robbins, Rebecca J; Leonczak, Jadwiga; Johnson, J Christopher; Li, Julia; Kwik-Uribe, Catherine; Prior, Ronald L; Gu, Liwei

2009-06-12

The quantitative parameters and method performance for a normal-phase HPLC separation of flavanols and procyanidins in chocolate and cocoa-containing food products were optimized and assessed. Single laboratory method performance was examined over three months using three separate secondary standards. RSD(r) ranged from 1.9%, 4.5% to 9.0% for cocoa powder, liquor and chocolate samples containing 74.39, 15.47 and 1.87 mg/g flavanols and procyanidins, respectively. Accuracy was determined by comparison to the NIST Standard Reference Material 2384. Inter-lab assessment indicated that variability was quite low for seven different cocoa-containing samples, with a RSD(R) of less than 10% for the range of samples analyzed.

Validation of the iHealth BP3 upper-arm blood pressure monitor, for clinic use and self-measurement, according to the European Society of Hypertension International Protocol revision 2010.

PubMed

Chen, Can; Shang, Fujun; Wang, Jiepin; Chen, Jianghong; Ji, Na; Wan, Yi

2012-12-01

This study aimed to evaluate the performance of the iHealth BP3 upper-arm blood pressure monitor, which is designed for clinic use and self-measurement of blood pressure using Apple touch devices as an interface. The European Society of Hypertension International Protocol (ESH-IP) revision 2010 for the validation of blood pressure measuring devices in adults was followed precisely. Ninty-nine couples of test device and reference blood pressure measurements were obtained during the study (three pairs for each of the 33 participants). The 33 participants, age 47.1±12.3 years (age range 27-69 years) and arm circumference 30.0±4.4 cm, had a mean systolic blood pressure (SBP) of 143.9±27.4 mmHg and a mean diastolic blood pressure (DBP) of 90.1±18.3 mmHg. The device passed all of the requirements fulfilling the standards of the protocol, and the mean±SD device-observer difference was 2.8±4.2 mmHg for SBP and -0.4±3.5 mmHg for DBP. According to the results of the validation study on the basis of the ESH-IP revision 2010, the iHealth BP3 can be recommended for clinic use and self-measurement in an adult population. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

76 FR 60083 - Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Japan and Romania

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-28

... Alloy Seamless Standard, Line, and Pressure Pipe From Japan and Romania Determinations On the basis of... pressure pipe from Japan and Romania would be likely to lead to continuation or recurrence of material... Seamless Standard, Line, and Pressure Pipe from Japan and Romania: Investigation Nos. 731-TA-847 and 849...

Realization of the medium and high vacuum primary standard in CENAM, Mexico

NASA Astrophysics Data System (ADS)

Torres-Guzman, J. C.; Santander, L. A.; Jousten, K.

2005-12-01

A medium and high vacuum primary standard, based on the static expansion method, has been set up at Centro Nacional de Metrología (CENAM), Mexico. This system has four volumes and covers a measuring range of 1 × 10-5 Pa to 1 × 103 Pa of absolute pressure. As part of its realization, a characterization was performed, which included volume calibrations, several tests and a bilateral key comparison. To determine the expansion ratios, two methods were applied: the gravimetric method and the method with a linearized spinning rotor gauge. The outgassing ratios for the whole system were also determined. A comparison was performed with Physikalisch-Technische Bundesanstalt (comparison SIM-Euromet.M.P-BK3). By means of this comparison, a link has been achieved with the Euromet comparison (Euromet.M.P-K1.b). As a result, it is concluded that the value obtained at CENAM is equivalent to the Euromet reference value, and therefore the design, construction and operation of CENAM's SEE-1 vacuum primary standard were successful.

Telemetry Standards, RCC Standard 106-17. Chapter 3. Frequency Division Multiplexing Telemetry Standards

DTIC Science & Technology

2017-07-01

any of the listed reference frequencies may be used provided the requirements for compensation rate of change are satisfied. If the reference...for in present discriminator systems when the nominal response rating of the channels is employed and a reference frequency is recorded with the...Telemetry Standards, RCC Standard 106-17 Chapter 3, July 2017 3-i CHAPTER 3 Frequency Division Multiplexing Telemetry Standards Acronyms

Effect of inlet-air humidity, temperature, pressure, and reference Mach number on the formation of oxides of nitrogen in a gas turbine combustor

NASA Technical Reports Server (NTRS)

Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

1973-01-01

Tests were conducted to determine the effect of inlet air humidity on the formation of oxides of nitrogen (NOx) from a gas turbine combustor. Combustor inlet air temperature ranged from 506 K (450 F) to 838 K (1050 F). The tests were primarily run at a constant pressure of 6 atmospheres and reference Mach number of 0.065. The NOx emission index was found to decrease with increasing inlet air humidity at a constant exponential rate: NOx = NOx0e-19H (where H is the humidity and the subscript 0 denotes the value at zero humidity). the emission index increased exponentially with increasing normalized inlet air temperature to the 1.14 power. Additional tests made to determine the effect of pressure and reference Mach number on NOx showed that the NOx emission index varies directly with pressure to the 0.5 power and inversely with reference Mach number.

Rapid wide-scope screening of drugs of abuse, prescription drugs with potential for abuse and their metabolites in influent and effluent urban wastewater by ultrahigh pressure liquid chromatography-quadrupole-time-of-flight-mass spectrometry.

PubMed

Hernández, Félix; Bijlsma, Lubertus; Sancho, Juan V; Díaz, Ramon; Ibáñez, María

2011-01-17

This work illustrates the potential of hybrid quadrupole-time-of-flight mass spectrometry (QTOF MS) coupled to ultrahigh pressure liquid chromatography (UHPLC) to investigate the presence of drugs of abuse in wastewater. After solid-phase extraction with Oasis MCX cartridges, seventy-six illicit drugs, prescription drugs with potential for abuse, and metabolites were investigated in the samples by TOF MS using electrospray interface under positive ionization mode, with MS data acquired over an m/z range of 50-1000Da. For 11 compounds, reference standards were available, and experimental data (e.g., retention time and fragmentation data) could be obtained, facilitating a more confident identification. The use of a QTOF instrument enabled the simultaneous application of two acquisition functions with different collision energies: a low energy (LE) function, where none or poor fragmentation took place, and a high energy (HE) function, where fragmentation in the collision cell was promoted. This approach, known as MS(E), enabled the simultaneous acquisition of full-spectrum accurate mass data of both protonated molecules and fragment ions in a single injection, providing relevant information that facilitates the rapid detection and reliable identification of these emerging contaminants in the sample matrices analyzed. In addition, isomeric compounds, like the opiates, morphine and norcodeine, could be discriminated by their specific fragments observed in HE TOF MS spectra, without the need of reference standards. UHPLC-QTOF MS was proven to be a powerful and efficient technique for rapid wide-scope screening and identification of many relevant drugs in complex matrices, such as influent and effluent urban wastewater. Copyright © 2010 Elsevier B.V. All rights reserved.

Concurrent validity and reliability of using ground reaction force and center of pressure parameters in the determination of leg movement initiation during single leg lift.

PubMed

Aldabe, Daniela; de Castro, Marcelo Peduzzi; Milosavljevic, Stephan; Bussey, Melanie Dawn

2016-09-01

Postural adjustment evaluations during single leg lift requires the initiation of heel lift (T1) identification. T1 measured by means of motion analyses system is the most reliable approach. However, this method involves considerable workspace, expensive cameras, and time processing data and setting up laboratory. The use of ground reaction forces (GRF) and centre of pressure (COP) data is an alternative method as its data processing and setting up is less time consuming. Further, kinetic data is normally collected using frequency samples higher than 1000Hz whereas kinematic data are commonly captured using 50-200Hz. This study describes the concurrent-validity and reliability of GRF and COP measurements in determining T1, using a motion analysis system as reference standard. Kinematic and kinetic data during single leg lift were collected from ten participants. GRF and COP data were collected using one and two force plates. Displacement of a single heel marker was captured by means of ten Vicon(©) cameras. Kinetic and kinematic data were collected using a sample frequency of 1000Hz. Data were analysed in two stages: identification of key events in the kinetic data, and assessing concurrent validity of T1 based on the chosen key events with T1 provided by the kinematic data. The key event presenting the least systematic bias, along with a narrow 95% CI and limits of agreement against the reference standard T1, was the Baseline COPy event. Baseline COPy event was obtained using one force plate and presented excellent between-tester reliability. Copyright © 2016 Elsevier B.V. All rights reserved.

Developing an Android-Based Patient Decision Aid Based on Ottawa Standards for Patients After Kidney Transplant and Its Usability Evaluation.

PubMed

Zare Moayedi, Mahboobeh; Aslani, Azam; Fakhrahmad, Mostafa; Ezzatzadegan J, Shahrokh

2018-01-01

This study was conducted to develop an android based patient decision aid (PDA) as a self-care instrument for patients after kidney transplant and its usability evaluation. In this study, the systematic development process of Android-based self-care application for patients after kidney transplant based on Ottawa standard was included: scoping, assemble steering group, analysis of requirements, designing, develop of a prototype and system evaluation. The PDA is a self-triage system that will help early identification of risk symptoms in patients, and help manage them. System recommendations for risk signs are: Refer to the nearest hospital or healthcare center without delay, refer to the doctor and tell your doctor in the next visit. To identify patient care needs, a semi-structured interview with members of steering group, including patients and clinical experts, was conducted by the researchers. A prototype of the decision aid was made according to identified needs in the previous step. Finally, in order to evaluate its usability rate by using the System Usability Scale (SUS) questionnaire, it was used by exerts and patients. This study identified information needs, risk signs and steps that patients need to make appropriate decisions about them. The main capabilities of the decision aid are features such as reminders for appointment/test, time of taking medication, registration of symptoms, weight, blood pressure, body temperature, advising to patient in case of signs of risk, weight, blood pressure, body temperature and test results which were reported in the diagram. The mean score of system's usability evaluated by medical informatics specialists, clinicians, and patients were 88.33, 95, and 91. PDAs was usable and desirable from the point of view of medical informatics specialists, clinicians and patients.

TU-G-204-01: BEST IN PHYSICS (IMAGING): Dynamic CT Myocardial Perfusion Measurement and Its Comparison to Fractional Flow Reserve

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziemer, B; Hubbard, L; Groves, E

2015-06-15

Purpose: To evaluate a first pass analysis (FPA) technique for CT perfusion measurement in a swine animal and its validation using fractional flow reserve (FFR) as a reference standard. Methods: Swine were placed under anesthesia and relevant physiologic parameters were continuously recorded. Intra-coronary adenosine was administered to induce maximum hyperemia. A pressure wire was advanced distal to the first diagonal branch of the left anterior descending (LAD) artery for FFR measurements and a balloon dilation catheter was inserted over the pressure wire into the proximal LAD to create varying levels of stenosis. Images were acquired with a 320-row wide volumemore » CT scanner. Three main coronary perfusion beds were delineated in the myocardium using arteries extracted from CT angiography images using a minimum energy hypothesis. The integrated density in the perfusion bed was used to calculate perfusion using the FPA technique. The perfusion in the LAD bed over a range of stenosis severity was measured. The measured fractional perfusion was compared to FFR and linear regression was performed. Results: The measured fractional perfusion using the FPA technique (P-FPA) and FFR were related as P-FPA = 1.06FFR – 0.06 (r{sup 2} = 0.86). The perfusion measurements were calculated with only three to five total CT volume scans, which drastically reduces the radiation dose as compared with the existing techniques requiring 15–20 volume scans. Conclusion: The measured perfusion using the first pass analysis technique showed good correlation with FFR measurements as a reference standard. The technique for perfusion measurement can potentially make a substantial reduction in radiation dose as compared with the existing techniques.« less

European multicentre validation study of the accuracy of E/e' ratio in estimating invasive left ventricular filling pressure: EURO-FILLING study.

PubMed

Galderisi, Maurizio; Lancellotti, Patrizio; Donal, Erwan; Cardim, Nuno; Edvardsen, Thor; Habib, Gilbert; Magne, Julien; Maurer, Gerald; Popescu, Bogdan A

2014-07-01

The non-invasive estimation of left ventricular filling pressures (LVFPs) represents a main goal in the clinical setting. Current recommendations encourage the use of pulsed-wave Tissue Doppler for calculating the ratio between the preload-dependent transmitral E velocity and the average of septal and lateral early diastolic velocities (e') of the mitral annulus. Despite its wide use, real utility of the E/e' ratio has been recently challenged in patients with either very advanced heart failure or preserved left ventricular (LV) ejection fraction. However, only few studies performed the invasive and non-invasive estimation of LVFP simultaneously. The EURO-FILLING Study will validate the E/e' ratio (and additional non-invasive estimates) against simultaneously measured LVFP obtained by left heart catheterization in a multicentre study involving reference European echo laboratories collecting a wide population sample size of cardiac patients with and without heart failure. The EURO-FILLING study is a large, prospective observational study in which simultaneous assessment of invasive and non-invasive measurements of LVFP will be acquired in eight reference European centres. Centralized reading of the collected parameters will be performed in a core laboratory. Not only standardized echo Doppler measurements but also novel echo parameters such as LV global longitudinal strain and global atrial strain (obtainable by two-dimensional speckle tracking echocardiography) will be tested for predicting invasive measurements of LVFP. The EURO-FILLING study is expected to provide important information on non-invasive assessment of LVFP and to contribute to the standardization of this assessment in clinical practice. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

49 CFR 1019.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 8 2011-10-01 2011-10-01 false Cross-reference to employee ethical conduct... Cross-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees of the Surface Transportation Board also should refer to the executive branch Standards of Ethical...

49 CFR 1019.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 8 2010-10-01 2010-10-01 false Cross-reference to employee ethical conduct... Cross-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees of the Surface Transportation Board also should refer to the executive branch Standards of Ethical...

49 CFR 1019.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 8 2014-10-01 2014-10-01 false Cross-reference to employee ethical conduct... Cross-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees of the Surface Transportation Board also should refer to the executive branch Standards of Ethical...

49 CFR 1019.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 8 2013-10-01 2013-10-01 false Cross-reference to employee ethical conduct... Cross-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees of the Surface Transportation Board also should refer to the executive branch Standards of Ethical...

49 CFR 1019.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 8 2012-10-01 2012-10-01 false Cross-reference to employee ethical conduct... Cross-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees of the Surface Transportation Board also should refer to the executive branch Standards of Ethical...

76 FR 44608 - Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Japan and Romania; Scheduling of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-26

... Alloy Seamless Standard, Line, and Pressure Pipe From Japan and Romania; Scheduling of Expedited Five-Year Reviews Concerning the Antidumping Duty Orders on Carbon and Alloy Seamless Standard, Line, and... the antidumping duty orders on carbon and alloy seamless standard, line, and pressure pipe from Japan...

75 FR 18153 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Japan...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-09

... Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Japan: Extension of Time Limit for... review of the antidumping duty order on certain large diameter carbon and alloy seamless standard, line... Carbon and Alloy Seamless Standard, Line and Pressure Pipe from Japan: Extension of Time Limit for...

Development and field testing of a rapid and ultra-stable atmospheric carbon dioxide spectrometer

DOE PAGES

Xiang, B.; Nelson, D. D.; McManus, J. B.; ...

2014-12-15

We present field test results for a new spectroscopic instrument to measure atmospheric carbon dioxide (CO 2) with high precision (0.02 μmol mol -1, or ppm at 1 Hz) and demonstrate high stability (within 0.1 ppm over more than 8 months), without the need for hourly, daily, or even monthly calibration against high-pressure gas cylinders. The technical novelty of this instrument (ABsolute Carbon dioxide, ABC) is the spectral null method using an internal quartz reference cell with known CO 2 column density. Compared to a previously described prototype, the field instrument has better stability and benefits from more precise thermalmore » control of the optics and more accurate pressure measurements in the sample cell (at the mTorr level). The instrument has been deployed at a long-term ecological research site (the Harvard Forest, USA), where it has measured for 8 months without on-site calibration and with minimal maintenance, showing drift bounds of less than 0.1 ppm. Field measurements agree well with those of a commercially available cavity ring-down CO 2 instrument (Picarro G2301) run with a standard calibration protocol. This field test demonstrates that ABC is capable of performing high-accuracy, unattended, continuous field measurements with minimal use of reference gas cylinders.« less

Development and field testing of a rapid and ultra-stable atmospheric carbon dioxide spectrometer

NASA Astrophysics Data System (ADS)

Xiang, B.; Nelson, D. D.; McManus, J. B.; Zahniser, M. S.; Wehr, R. A.; Wofsy, S. C.

2014-12-01

We present field test results for a new spectroscopic instrument to measure atmospheric carbon dioxide (CO2) with high precision (0.02 μmol mol-1, or ppm at 1 Hz) and demonstrate high stability (within 0.1 ppm over more than 8 months), without the need for hourly, daily, or even monthly calibration against high-pressure gas cylinders. The technical novelty of this instrument (ABsolute Carbon dioxide, ABC) is the spectral null method using an internal quartz reference cell with known CO2 column density. Compared to a previously described prototype, the field instrument has better stability and benefits from more precise thermal control of the optics and more accurate pressure measurements in the sample cell (at the mTorr level). The instrument has been deployed at a long-term ecological research site (the Harvard Forest, USA), where it has measured for 8 months without on-site calibration and with minimal maintenance, showing drift bounds of less than 0.1 ppm. Field measurements agree well with those of a commercially available cavity ring-down CO2 instrument (Picarro G2301) run with a standard calibration protocol. This field test demonstrates that ABC is capable of performing high-accuracy, unattended, continuous field measurements with minimal use of reference gas cylinders.

Non-Invasive Method of Determining Absolute Intracranial Pressure

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

2004-01-01

A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

Vapor pressures of a homologous series of polyethylene glycols as a reference data set for validating vapor pressure measurement techniques.

NASA Astrophysics Data System (ADS)

Krieger, Ulrich; Marcolli, Claudia; Siegrist, Franziska

2015-04-01

The production of secondary organic aerosol (SOA) by gas-to-particle partitioning is generally represented by an equilibrium partitioning model. A key physical parameter which governs gas-particle partitioning is the pure component vapor pressure, which is difficult to measure for low- and semivolatile compounds. For typical atmospheric compounds like e.g. citric acid or tartaric acid, vapor pressures have been reported in the literature which differ by up to six orders of magnitude [Huisman et al., 2013]. Here, we report vapor pressures of a homologous series of polyethylene glycols (triethylene glycol to octaethylene glycol) determined by measuring the evaporation rate of single, levitated aerosol particles in an electrodynamic balance. We propose to use those as a reference data set for validating different vapor pressure measurement techniques. With each addition of a (O-CH2-CH2)-group the vapor pressure is lowered by about one order of magnitude which makes it easy to detect the lower limit of vapor pressures accessible with a particular technique down to a pressure of 10-8 Pa at room temperature. Reference: Huisman, A. J., Krieger, U. K., Zuend, A., Marcolli, C., and Peter, T., Atmos. Chem. Phys., 13, 6647-6662, 2013.

On the interfacial thermodynamics of nanoscale droplets and bubbles

NASA Astrophysics Data System (ADS)

Corti, David S.; Kerr, Karl J.; Torabi, Korosh

2011-07-01

We present a new self-consistent thermodynamic formalism for the interfacial properties of nanoscale embryos whose interiors do not exhibit bulklike behavior and are in complete equilibrium with the surrounding mother phase. In contrast to the standard Gibbsian analysis, whereby a bulk reference pressure based on the same temperature and chemical potentials of the mother phase is introduced, our approach naturally incorporates the normal pressure at the center of the embryo as an appropriate reference pressure. While the interfacial properties of small embryos that follow from the use of these two reference pressures are different, both methods yield by construction the same reversible work of embryo formation as well as consistency between their respective thermodynamic and mechanical routes to the surface tension. Hence, there is no a priori reason to select one method over another. Nevertheless, we argue, and demonstrate via a density-functional theory (with the local density approximation) analysis of embryo formation in the pure component Lennard-Jones fluid, that our new method generates more physically appealing trends. For example, within the new approach the surface tension at all locations of the dividing surface vanishes at the spinodal where the density profile spanning the embryo and mother phase becomes completely uniform (only the surface tension at the Gibbs surface of tension vanishes in the Gibbsian method at this same limit). Also, for bubbles, the location of the surface of tension now diverges at the spinodal, similar to the divergent behavior exhibited by the equimolar dividing surface (in the Gibbsian method, the location of the surface of tension vanishes instead). For droplets, the new method allows for the appearance of negative surface tensions (the Gibbsian method always yields positive tensions) when the normal pressures within the interior of the embryo become less than the bulk pressure of the surrounding vapor phase. Such a prediction, which is allowed by thermodynamics, is consistent with the interpretation that the mother phase's attempted compression of the droplet is counterbalanced by the negative surface tension, or free energy cost to decrease the interfacial area. Furthermore, for these same droplets, the surface of tension can no longer be meaningfully defined (the surface of tension always remains well defined in the Gibbsian method). Within the new method, the dividing surface at which the surface tension equals zero emerges as a new lengthscale, which has various thermodynamic analogs to and similar behavior as the surface of tension.

Pneumatic pressure wave generator provides economical, simple testing of pressure transducers

NASA Technical Reports Server (NTRS)

Gaal, A. E.; Weldon, T. P.

1967-01-01

Testing device utilizes the change in pressure about a bias or reference pressure level produced by displacement of a center-driven piston in a closed cylinder. Closely controlled pneumatic pressure waves allow testing under dynamic conditions.

From plastic to gold: a unified classification scheme for reference standards in medical image processing

NASA Astrophysics Data System (ADS)

Lehmann, Thomas M.

2002-05-01

Reliable evaluation of medical image processing is of major importance for routine applications. Nonetheless, evaluation is often omitted or methodically defective when novel approaches or algorithms are introduced. Adopted from medical diagnosis, we define the following criteria to classify reference standards: 1. Reliance, if the generation or capturing of test images for evaluation follows an exactly determined and reproducible protocol. 2. Equivalence, if the image material or relationships considered within an algorithmic reference standard equal real-life data with respect to structure, noise, or other parameters of importance. 3. Independence, if any reference standard relies on a different procedure than that to be evaluated, or on other images or image modalities than that used routinely. This criterion bans the simultaneous use of one image for both, training and test phase. 4. Relevance, if the algorithm to be evaluated is self-reproducible. If random parameters or optimization strategies are applied, reliability of the algorithm must be shown before the reference standard is applied for evaluation. 5. Significance, if the number of reference standard images that are used for evaluation is sufficient large to enable statistically founded analysis. We demand that a true gold standard must satisfy the Criteria 1 to 3. Any standard only satisfying two criteria, i.e., Criterion 1 and Criterion 2 or Criterion 1 and Criterion 3, is referred to as silver standard. Other standards are termed to be from plastic. Before exhaustive evaluation based on gold or silver standards is performed, its relevance must be shown (Criterion 4) and sufficient tests must be carried out to found statistical analysis (Criterion 5). In this paper, examples are given for each class of reference standards.

28 CFR 45.1 - Cross-reference to ethical standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Cross-reference to ethical standards and...) EMPLOYEE RESPONSIBILITIES § 45.1 Cross-reference to ethical standards and financial disclosure regulations. Employees of the Department of Justice are subject to the executive branch-wide Standards of Ethical Conduct...

10 CFR 1010.102 - Cross-references to employee ethical conduct standards, financial disclosure regulations, and...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Cross-references to employee ethical conduct standards... Cross-references to employee ethical conduct standards, financial disclosure regulations, and other conduct rules. Employees of DOE are subject to the Standards of Ethical Conduct for Employees of the...

28 CFR 45.1 - Cross-reference to ethical standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Cross-reference to ethical standards and...) EMPLOYEE RESPONSIBILITIES § 45.1 Cross-reference to ethical standards and financial disclosure regulations. Employees of the Department of Justice are subject to the executive branch-wide Standards of Ethical Conduct...

10 CFR 1010.102 - Cross-references to employee ethical conduct standards, financial disclosure regulations, and...

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Cross-references to employee ethical conduct standards... Cross-references to employee ethical conduct standards, financial disclosure regulations, and other conduct rules. Employees of DOE are subject to the Standards of Ethical Conduct for Employees of the...

10 CFR 1010.102 - Cross-references to employee ethical conduct standards, financial disclosure regulations, and...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Cross-references to employee ethical conduct standards... Cross-references to employee ethical conduct standards, financial disclosure regulations, and other conduct rules. Employees of DOE are subject to the Standards of Ethical Conduct for Employees of the...

28 CFR 45.1 - Cross-reference to ethical standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Cross-reference to ethical standards and...) EMPLOYEE RESPONSIBILITIES § 45.1 Cross-reference to ethical standards and financial disclosure regulations. Employees of the Department of Justice are subject to the executive branch-wide Standards of Ethical Conduct...

10 CFR 1010.102 - Cross-references to employee ethical conduct standards, financial disclosure regulations, and...

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Cross-references to employee ethical conduct standards... Cross-references to employee ethical conduct standards, financial disclosure regulations, and other conduct rules. Employees of DOE are subject to the Standards of Ethical Conduct for Employees of the...

28 CFR 45.1 - Cross-reference to ethical standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Cross-reference to ethical standards and...) EMPLOYEE RESPONSIBILITIES § 45.1 Cross-reference to ethical standards and financial disclosure regulations. Employees of the Department of Justice are subject to the executive branch-wide Standards of Ethical Conduct...

28 CFR 45.1 - Cross-reference to ethical standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Cross-reference to ethical standards and...) EMPLOYEE RESPONSIBILITIES § 45.1 Cross-reference to ethical standards and financial disclosure regulations. Employees of the Department of Justice are subject to the executive branch-wide Standards of Ethical Conduct...

A comparison of three infant skinfold reference standards: Tanner-Whitehouse, Cambridge Infant Growth Study, and WHO Child Growth Standards.

PubMed

Miller, Elizabeth M

2015-10-01

As researchers increasingly focus on early infancy as a critical period of development, there is a greater need for methodological tools that can address all aspects of infant growth. Infant skinfold measures, in particular, are measurements in need of reliable reference standards that encompass all ages of infants and provide an accurate assessment of the relative fatness of a population. This report evaluates three published reference standards for infant skinfold measurements: Tanner-Whitehouse, Cambridge Infant Growth Study, and the World Health Organization (WHO) Child Growth Standards. To assess these standards, triceps skinfolds from a population of rural Kenyan infants (n = 250) and triceps skinfolds and subscapular skinfolds from infants in the National Health and Nutrition Examination Survey 1999-2002 (NHANES; n = 1197) were calculated as z-scores from the lambda-mu-sigma curves provided by each reference population. The Tanner-Whitehouse standards represented both the Kenyan and US populations as lean, while the Cambridge standards represented both populations as overfat. The distribution of z-scores based on the WHO standards fell in the middle, but excluded infants from both populations who were below the age of 3 months. Based on these results, the WHO reference standard is the best skinfold reference standard for infants over the age of 3 months. For populations with infants of all ages, the Tanner-Whitehouse standards are recommended, despite representing both study populations as underfat. Ideally, the WHO will extend their reference standard to include infants between the ages of 0 and 3 months. © 2014 John Wiley & Sons Ltd.

Pressurized Pepsin Digestion in Proteomics: An Automatable Alternative to Trypsin for Integrated Top-down Bottom-up Proteomics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez-Ferrer, Daniel; Petritis, Konstantinos; Robinson, Errol W.

2011-02-01

Integrated top-down bottom-up proteomics combined with online digestion has great potential to improve the characterization of protein isoforms in biological systems and is amendable to highthroughput proteomics experiments. Bottom-up proteomics ultimately provides the peptide sequences derived from the tandem MS analyses of peptides after the proteome has been digested. Top-down proteomics conversely entails the MS analyses of intact proteins for more effective characterization of genetic variations and/or post-translational modifications (PTMs). Herein, we describe recent efforts towards efficient integration of bottom-up and top-down LCMS based proteomic strategies. Since most proteomic platforms (i.e. LC systems) operate in acidic environments, we exploited themore » compatibility of the pepsin (i.e. the enzyme’s natural acidic activity) for the integration of bottom-up and top-down proteomics. Pressure enhanced pepsin digestions were successfully performed and characterized with several standard proteins in either an offline mode using a Barocycler or an online mode using a modified high pressure LC system referred to as a fast online digestion system (FOLDS). FOLDS was tested using pepsin and a whole microbial proteome, and the results compared against traditional trypsin digestions on the same platform. Additionally, FOLDS was integrated with a RePlay configuration to demonstrate an ultra-rapid integrated bottom-up top-down proteomic strategy employing a standard mixture of proteins and a monkey pox virus proteome.« less

Numerical Study of Pressure Field in Laterally Closed Industrial Buildings with Curved Metallic Roofs due to the Wind Effect by FEM and European Rule Comparison

NASA Astrophysics Data System (ADS)

Nieto, P. J. García; del Coz Díaz, J. J.; Vilán, J. A. Vilán; Placer, C. Casqueiro

2009-08-01

In this paper, an evaluation of distribution of the air pressure is determined throughout the laterally closed industrial buildings with curved metallic roofs due to the wind effect by the finite element method (FEM). The non-linearity is due to Reynolds-averaged Navier-Stokes (RANS) equations that govern the turbulent flow. The Navier-Stokes equations are non-linear partial differential equations and this non-linearity makes most problems difficult to solve and is part of the cause of turbulence. The RANS equations are time-averaged equations of motion for fluid flow. They are primarily used while dealing with turbulent flows. Turbulence is a highly complex physical phenomenon that is pervasive in flow problems of scientific and engineering concern like this one. In order to solve the RANS equations a two-equation model is used: the standard k-ɛ model. The calculation has been carried out keeping in mind the following assumptions: turbulent flow, an exponential-like wind speed profile with a maximum velocity of 40 m/s at 10 m reference height, and different heights of the building ranging from 6 to 10 meters. Finally, the forces and moments are determined on the cover, as well as the distribution of pressures on the same one, comparing the numerical results obtained with the Spanish CTE DB SE-AE, Spanish NBE AE-88 and European standard rules, giving place to the conclusions that are exposed in the study.

Optimising the Number of Replicate- Versus Standard Measurements for Carbonate Clumped Isotope Thermometry

NASA Astrophysics Data System (ADS)

Kocken, I.; Ziegler, M.

2017-12-01

Clumped isotope measurements on carbonates are a quickly developing and promising palaeothermometry proxy1-3. Developments in the field have brought down the necessary sample amount and improved the precision and accuracy of the measurements. The developments have included inter-laboratory comparison and the introduction of an absolute reference frame4, determination of acid fractionation effects5, correction for the pressure baseline6, as well as improved temperature calibrations2, and most recently new approaches to improve efficiency in terms of sample gas usage7. However, a large-scale application of clumped isotope thermometry is still hampered by required large sample amounts, but also the time-consuming analysis. In general, a lot of time is goes into the measurement of standards. Here we present a study on the optimal ratio between standard- and sample measurements using the Kiel Carbonate Device method. We also consider the optimal initial signal intensity. We analyse ETH-standard measurements from several months to determine the measurement regime with the highest precision and optimised measurement time management.References 1. Eiler, J. M. Earth Planet. Sci. Lett. 262, 309-327 (2007).2. Kelson, J. R., et al. Geochim. Cosmochim. Acta 197, 104-131 (2017).3. Kele, S. et al. Geochim. Cosmochim. Acta 168, 172-192 (2015).4. Dennis, K. J. et al. Geochim. Cosmochim. Acta 75, 7117-7131 (2011).5. Müller, I. A. et al. Chem. Geol. 449, 1-14 (2017).6. Meckler, A. N. et al. Rapid Commun. Mass Spectrom. 28, 1705-1715 (2014).7. Hu, B. et al. Rapid Commun. Mass Spectrom. 28, 1413-1425 (2014).

Recent progress in high pressure metrology in Europe

NASA Astrophysics Data System (ADS)

Sabuga, Wladimir; Pražák, Dominik; Rabault, Thierry

2014-08-01

Five European national metrology institutes in collaboration with a university, a research institute and five industrial companies are working on a joint research project within a framework of the European Metrology Research Programme aimed at development of 1.6 GPa primary and 1.5 GPa transfer pressure standards. Two primary pressure standards were realised as pressure-measuring multipliers, each consisting of a low pressure and a high pressure (HP) piston-cylinder assembly (PCA). A special design of the HP PCAs was developed in which a tungsten carbide cylinder is supported by two thermally shrunk steel sleeves and, additionally, by jacket pressure applied to the outside of the outer sleeve. Stress-strain finite element analysis (FEA) was performed to predict behaviour of the multipliers and a pressure generation system. With FEA, the pressure distortion coefficient was determined, taking into account irregularities of the piston-cylinder gap. Transfer pressure standards up to 1.5 GPa are developed on the basis of modern 1.5 GPa pressure transducers. This project shall solve a discrepancy between the growing needs of the industry demanding precise traceable calibrations of the high pressure transducers and the absence of adequate primary standards for pressures higher than 1 GPa in the European Union today.

A pilot study of reference vibrotactile perception thresholds on the fingertip obtained with Malaysian healthy people using ISO 13091-1 equipment.

PubMed

Daud, Roshada; Maeda, Setsuo; Kameel, Nur Nazmin Mustafa; Ripin, Muhamad Yunus; Bakrun, Norazman; Md Zein, Raemy; Kido, Masaharu; Higuchi, Kiyotaka

2004-04-01

The purpose of this paper is to clarify the reference vibrotactile perception thresholds (VPT) for healthy people in Malaysia. The measurement equipment standard, ISO 13091-1, of the vibrotactile perception thresholds for the assessment of nerve dysfunction and the analysis and interpretation of measurements at the fingertips standard, ISO 13091-2, were published in ISO/TC108/SC4/WG8 on 2001 and 2003 individually. In the ISO 13091-2 standard, the reference VPT data were obtained from few research papers. Malaysian people's VPT data don't include to this standard. In Malaysia, when the VPT is using to diagnose of the hand-arm vibration syndrome, the reference VPT data need to compare with the worker's ones. But, Malaysia does not have the reference VPT data yet. So, in this paper, the VPT was measured by using ISO 13091-1 standard equipment to obtain the reference data for Malaysian people. And these data were compared with the ISO reference data on the ISO 13091-2 standard. From the comparison of these data, it was clear that the Malaysian healthy people's VPT data were consistent with the reference data of the ISO 13091-2 standard.

The impact of US versus Indian BMD reference standards on the diagnosis of osteoporosis among South Asian Indians living in the United States

PubMed Central

Melamed, Alexander; Vittinghoff, Eric; Sriram, Usha; Schwartz, Ann V.; Kanaya, Alka M.

2010-01-01

The relationship between bone mineral density (BMD) and fracture risk is not well-established for non-white populations. There is no established BMD reference standard for South Asians. Dual energy x-ray absorptiometry (DXA) was used to measure BMD at total hip and lumbar spine in 150 US-based South Asian Indians. For each subject T-scores were calculated using BMD reference values based on US white, North Indian and South Indian populations, and the resulting WHO BMD category assignments were compared. Reference standards derived from Indian populations classified a larger proportion of US-based Indians as normal than did US white-based standards. The percentage of individuals reclassified when changing between reference standards varied by skeletal site and reference population origin, ranging from 13% (95% CI, 7–18%), when switching from US-white- to North Indian-based standard for total hip, to 40% (95% CI, 32–48%), when switching from US white to South Indian reference values for lumbar spine. These finding illustrate that choice of reference standard has a significant effect on the diagnosis of osteoporosis in South Asians, and underscore the importance of future research to quantify the relationship between BMD and fracture risk in this population. PMID:20663699

76 FR 8989 - Federal Acquisition Regulation; Updated Financial Accounting Standards Board Accounting References

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-16

... Acquisition Regulation; Updated Financial Accounting Standards Board Accounting References AGENCIES... Acquisition Regulation (FAR) to update references to authoritative accounting standards owing to the Financial... Accounting Principles (GAAP) (``Codification of GAAP''). DATES: Interested parties should submit written...

In vitro vaccine potency testing: a proposal for reducing animal use for requalification testing.

PubMed

Brown, K; Stokes, W

2012-01-01

This paper proposes a program under which the use of animals for requalification of in vitro potency tests could be eliminated. Standard References (USDA/CVB nomenclature) would be developed, characterized, stored and monitored by selected reference laboratories worldwide. These laboratories would employ scientists skilled in protein and glycoprotein chemistry and equipped with state-of-the-art instruments for required analyses. After Standard References are established, the reference laboratories would provide them to the animal health industry as "gold standards". Companies would then establish and validate a correlation between the Standard Reference and the company Master Reference (USDA/CVB nomenclature) using an internal in vitro assay. After this correlation is established, the company could use the Standard References for qualifying, monitoring and requalifying company Master References without the use of animals. Such a program would eliminate the need for animals for requalification of Master References and the need for each company to develop and validate a battery of Master Reference Monitoring assays. It would also provide advantages in terms of reduced costs and reduced time for requalification testing. As such it would provide a strong incentive for companies to develop and use in vitro assays for potency testing.

Ventilation-Induced Modulation of Pulse Oximeter Waveforms: A Method for the Assessment of Early Changes in Intravascular Volume During Spinal Fusion Surgery in Pediatric Patients.

PubMed

Alian, Aymen A; Atteya, Gourg; Gaal, Dorothy; Golembeski, Thomas; Smith, Brian G; Dai, Feng; Silverman, David G; Shelley, Kirk

2016-08-01

Scoliosis surgery is often associated with substantial blood loss, requiring fluid resuscitation and blood transfusions. In adults, dynamic preload indices have been shown to be more reliable for guiding fluid resuscitation, but these indices have not been useful in children undergoing surgery. The aim of this study was to introduce frequency-analyzed photoplethysmogram (PPG) and arterial pressure waveform variables and to study the ability of these parameters to detect early bleeding in children during surgery. We studied 20 children undergoing spinal fusion. Electrocardiogram, arterial pressure, finger pulse oximetry (finger PPG), and airway pressure waveforms were analyzed using time domain and frequency domain methods of analysis. Frequency domain analysis consisted of calculating the amplitude density of PPG and arterial pressure waveforms at the respiratory and cardiac frequencies using Fourier analysis. This generated 2 measurements: The first is related to slow mean arterial pressure modulation induced by ventilation (also known as DC modulation when referring to the PPG), and the second corresponds to pulse pressure modulation (AC modulation or changes in the amplitude of pulse oximeter plethysmograph when referring to the PPG). Both PPG and arterial pressure measurements were divided by their respective cardiac pulse amplitude to generate DC% and AC% (normalized values). Standard hemodynamic data were also recorded. Data at baseline and after bleeding (estimated blood loss about 9% of blood volume) were presented as median and interquartile range and compared using Wilcoxon signed-rank tests; a Bonferroni-corrected P value <0.05 was considered statistically significant. There were significant increases in PPG DC% (median [interquartile range] = 359% [210 to 541], P = 0.002), PPG AC% (160% [87 to 251], P = 0.003), and arterial DC% (44% [19 to 84], P = 0.012) modulations, respectively, whereas arterial AC% modulations showed nonsignificant increase (41% [1 to 85], P = 0.12). The change in PPG DC% was significantly higher than that in PPG AC%, arterial DC%, arterial AC%, and systolic blood pressure with P values of 0.008, 0.002, 0.003, and 0.002, respectively. Only systolic blood pressure showed significant changes (11% [4 to 21], P = 0.003) between bleeding phase and baseline. Finger PPG and arterial waveform parameters (using frequency analysis) can track changes in blood volume during the bleeding phase, suggesting the potential for a noninvasive monitor for tracking changes in blood volume in pediatric patients. PPG waveform baseline modulation (PPG DC%) was more sensitive to changes in venous blood volume when compared with respiration-induced modulation seen in the arterial pressure waveform.

Ozone reference models for the middle atmosphere (new CIRA)

NASA Technical Reports Server (NTRS)

Keating, G. M.; Pitts, M. C.; Young, D. F.

1989-01-01

Models of ozone vertical structure were generated that were based on multiple data sets from satellites. The very good absolute accuracy of the individual data sets allowed the data to be directly combined to generate these models. The data used for generation of these models are from some of the most recent satellite measurements over the period 1978 to 1983. A discussion is provided of validation and error analyses of these data sets. Also, inconsistencies in data sets brought about by temporal variations or other factors are indicated. The models cover the pressure range from from 20 to 0.003 mb (25 to 90 km). The models for pressures less than 0.5 mb represent only the day side and are only provisional since there was limited longitudinal coverage at these levels. The models start near 25 km in accord with previous COSPAR international reference atmosphere (CIRA) models. Models are also provided of ozone mixing ratio as a function of height. The monthly standard deviation and interannual variations relative to zonal means are also provided. In addition to the models of monthly latitudinal variations in vertical structure based on satellite measurements, monthly models of total column ozone and its characteristic variability as a function of latitude based on four years of Nimbus 7 measurements, models of the relationship between vertical structure and total column ozone, and a midlatitude annual mean model are incorporated in this set of ozone reference atmospheres. Various systematic variations are discussed including the annual, semiannual, and quasibiennial oscillations, and diurnal, longitudinal, and response to solar activity variations.

Validation of the Microlife BP A3 PC upper arm blood pressure monitor in patients with diabetes mellitus according to the ANSI/AAMI/ISO 81060-2: 2013 protocol.

PubMed

Beime, Beate; Krüger, Ralf; Hammel, Gertrud; Bramlage, Peter; Deutsch, Cornelia

2018-02-01

The aim of the present study was to validate the blood pressure (BP) measurement device, Microlife BP A3 PC, in patients with diabetes mellitus, according to the ANSI/AAMI/ISO 81060-2:2013 protocol. In 85 individuals aged 56-88 years, with predefined criteria for diabetes mellitus, BP measurements on the upper arm were performed alternately using the Microlife BP A3 PC and a standard mercury reference sphygmomanometer. A total of 333 comparisons were included for analysis. The mean difference between the Microlife BP A3 PC and the reference was -1.5±6.3 mmHg for systolic BP (SBP) and -1.3±5.2 mmHg for diastolic BP (DBP) according to criterion 1 of the protocol. For SBP, a total of 209 of the 333 measurements were within the range of 5 mmHg (62.8%), whereas the corresponding numbers for DBP were 232 of 333 (69.7%). For criterion 2, the intraindividual differences for the test device and the reference were -1.50±4.73 mmHg for SBP and -1.30±4.55 mmHg for DBP, thus being within the defined ranges provided by the protocol. The Microlife BP A3 PC fulfilled the requirements of criteria 1 and 2 of the ANSI/AAMI/ISO 81060-2:2013 protocol and can also be recommended for BP measurement in diabetic patients.

Results from the Balloon Ozone Intercomparison Campaign (BOIC)

NASA Technical Reports Server (NTRS)

Hilsenrath, E.; Hagemeyer, R.; Mentall, J.; Torres, A.; Attmannspacher, W.; Bass, A.; Evans, W.; Barnes, R. A.; Komhyr, W.; Robbins, D.

1986-01-01

Data from the BOIC which consisted of three balloon missions conducted in Palestine, Texas from June 1983 to March 1984 are presented. The BOIC was to assess the ability to perform ozone measurements from balloon platforms. The accuracy and precision of the various ozone measurement systems, which were composed of a photometer, a mass spectrometer, and solar UV absorption sensors, are evaluated. The ozone observations obtained with the instruments on the three flight missions are analyzed and intercompared. The flight in situ data are also compared to the National Bureau of Standards reference photometer, satellite measurements, and under simulated stratospheric pressure and ozone concentrations.

Novel experimental design for high pressure-high temperature electrical resistance measurements in a "Paris-Edinburgh" large volume press.

PubMed

Matityahu, Shlomi; Emuna, Moran; Yahel, Eyal; Makov, Guy; Greenberg, Yaron

2015-04-01

We present a novel experimental design for high sensitivity measurements of the electrical resistance of samples at high pressures (0-6 GPa) and high temperatures (300-1000 K) in a "Paris-Edinburgh" type large volume press. Uniquely, the electrical measurements are carried out directly on a small sample, thus greatly increasing the sensitivity of the measurement. The sensitivity to even minor changes in electrical resistance can be used to clearly identify phase transitions in material samples. Electrical resistance measurements are relatively simple and rapid to execute and the efficacy of the present experimental design is demonstrated by measuring the electrical resistance of Pb, Sn, and Bi across a wide domain of temperature-pressure phase space and employing it to identify the loci of phase transitions. Based on these results, the phase diagrams of these elements are reconstructed to high accuracy and found to be in excellent agreement with previous studies. In particular, by mapping the locations of several well-studied reference points in the phase diagram of Sn and Bi, it is demonstrated that a standard calibration exists for the temperature and pressure, thus eliminating the need for direct or indirect temperature and pressure measurements. The present technique will allow simple and accurate mapping of phase diagrams under extreme conditions and may be of particular importance in advancing studies of liquid state anomalies.

Research of performance prediction to energy on hydraulic turbine

NASA Astrophysics Data System (ADS)

Quan, H.; Li, R. N.; Li, Q. F.; Han, W.; Su, Q. M.

2012-11-01

Refer to the low specific speed Francis turbine blade design principle and double-suction pump structure. Then, design a horizontal double-channel hydraulic turbine Francis. Through adding different guide vane airfoil and and no guide vane airfoil on the hydraulic conductivity components to predict hydraulic turbine energy and using Fluent software to numerical simulation that the operating conditions and point. The results show that the blade pressure surface and suction surface pressure is low when the hydraulic turbine installation is added standard positive curvature of the guide vane and modified positive curvature of guide vane. Therefore, the efficiency of energy recovery is low. However, the pressure of negative curvature guide vane and symmetric guide vane added on hydraulic turbine installations is larger than that of the former ones, and it is conducive to working of runner. With the decreasing of guide vane opening, increasing of inlet angle, flow state gets significantly worse. Then, others obvious phenomena are that the reflux and horizontal flow appeared in blade pressure surface. At the same time, the vortex was formed in Leaf Road, leading to the loss of energy. Through analyzing the distribution of pressure, velocity, flow lines of over-current flow in the the back hydraulic conductivity components in above programs we can known that the hydraulic turbine installation added guide vane is more reasonable than without guide vanes, it is conducive to improve efficiency of energy conversion.

[Nursing methodology applicated in patients with pressure ulcers. Clinical report].

PubMed

Galvez Romero, Carmen

2014-05-01

The application of functional patterns lets us to make a systematic and premeditated nursing assessment, with which we obtain a lot of relevant patient data in an organized way, making easier to analize them. In our case, we use Marjory Gordon's functional health patterns and NANDA (North American Nursing Diagnosis Association), NOC (Nursing Outcomes Classification), NIC (Nursing Intervention Classification) taxonomy. The overall objective of this paper is to present the experience of implementation and development of nursing methodology in the care of patients with pressure ulcers. In this article it's reported a case of a 52-year-old female who presented necrosis of phalanxes in upper and lower limbs and suffered amputations of them after being hospitalized in an Intensive Care Unit. She was discharged with pressure ulcers on both heels. GENERAL ASSESSMENT: It was implemented the nursing theory known as "Gordon's functional health patterns" and the affected patterns were identified. The Second Pattern (Nutritional-Metabolic) was considered as reference, since this was the pattern which altered the rest. EVOLUTION OF THE PATIENT: The patient had a favourable evolution, improving all the altered patterns. The infections symptoms disappeared and the pressure ulcers of both heels healed completely. The application of nursing methodology to care patients with pressure ulcers using clinical practice guidelines, standardized procedures and rating scales of assessment improves the evaluation of results and the performance of nurses.

Continuous ambulatory right heart pressure measurements with an implantable hemodynamic monitor: a multicenter, 12-month follow-up study of patients with chronic heart failure.

PubMed

Magalski, Anthony; Adamson, Philip; Gadler, Frederick; Böehm, Michael; Steinhaus, David; Reynolds, Dwight; Vlach, Kathryn; Linde, Cecilia; Cremers, Bodo; Sparks, Brandon; Bennett, Tom

2002-04-01

We describe the performance of an implantable hemodynamic monitor (IHM) that allows continuous recording of heart rate, patient activity levels, and right ventricular systolic, right ventricular diastolic, and estimated pulmonary artery diastolic pressures. Pressure parameters derived from the implantable monitor were correlated to measurements made with a balloon-tipped catheter to establish accuracy and reproducibility over time in patients with chronic heart failure (CHF). IHM devices were implanted in 32 patients with CHF (left ventricular ejection fraction, 29% +/- 11%; range, 14%-62%) and were tested with right heart catheterization at implantation and 3, 6, and 12 months later. Hemodynamic variables were digitally recorded simultaneously from the IHM and catheter. Values were recorded during supine rest, peak response of Valsalva maneuver, sitting, peak of a 2-stage (25-50 W) bicycle exercise test, and final rest period. The median of 21 paired beat-to-beat cardiac cycles was analyzed for each intervention. A total of 217 paired data values from all maneuvers were analyzed for 32 patients at implantation and 129 paired data values for 20 patients at 1 year. The IHM and catheter values were not different at baseline or at 1 year (P >.05). Combining all interventions, correlation coefficients were 0.96 and 0.94 for right ventricular systolic pressure, 0.96 and 0.83 for right ventricular diastolic pressure, and 0.87 and 0.87 for estimated pulmonary artery diastolic pressure at implantation and 1 year, respectively. The IHM and a standard reference pressure system recorded comparable right heart pressure values in patients with CHF. This implantable pressure transducer is accurate over time and provides a means to precisely monitor the hemodynamic condition of patients with CHF in a continuous fashion.

A study of pressure losses in residential air distribution systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abushakra, Bass; Walker, Iain S.; Sherman, Max H.

2002-07-01

An experimental study was conducted to evaluate the pressure drop characteristics of residential duct system components that are either not available or not thoroughly (sometimes incorrectly) described in existing duct design literature. The tests were designed to imitate cases normally found in typical residential and light commercial installations. The study included three different sizes of flexible ducts, under different compression configurations, splitter boxes, supply boots, and a fresh air intake hood. The experimental tests conformed to ASHRAE Standard 120P--''Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings''. The flexible duct study covered compressibility and bending effectsmore » on the total pressure drop, and the results showed that the available published references tend to underestimate the effects of compression in flexible ducts that can increase pressure drops by up to a factor of nine. The supply boots were tested under different configurations including a setup where a flexible duct elbow connection was considered as an integral part of the supply boot. The supply boots results showed that diffusers can increase the pressure drop by up to a factor of two in exit fittings, and the installation configuration can increase the pressure drop by up to a factor of five. The results showed that it is crucial for designers and contractors to be aware of the compressibility effects of the flexible duct, and the installation of supply boots and diffusers.« less

[Age- and sex-specific reference intervals for 10 health examination items: mega-data from a Japanese Health Service Association].

PubMed

Suka, Machi; Yoshida, Katsumi; Kawai, Tadashi; Aoki, Yoshikazu; Yamane, Noriyuki; Yamauchi, Kuniaki

2005-07-01

To determine age- and sex-specific reference intervals for 10 health examination items in Japanese adults. Health examination data were accumulated from 24 different prefectural health service associations affiliated with the Japan Association of Health Service. Those who were non-smokers, drank less than 7 days/week, and had a body mass index of 18.5-24.9kg/m2 were sampled as a reference population (n = 737,538; 224,947 men and 512,591 women). After classified by age and sex, reference intervals for 10 health examination items (systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, glucose, uric acid, AST, ALT, gamma-GT, and hemoglobin) were estimated using the parametric and nonparametric methods. In every item except for hemoglobin, men had higher reference intervals than women. Systolic blood pressure, total cholesterol, and glucose showed an upward trend in values with increasing age. Hemoglobin showed a downward trend in values with increasing age. Triglyceride, ALT, and gamma-GT reached a peak in middle age. Overall, parametric estimates showed narrower reference intervals than non-parametric estimates. Reference intervals vary with age and sex. Age- and sex-specific reference intervals may contribute to better assessment of health examination data.

Formulation of blade-flutter spectral analyses in stationary reference frame

NASA Technical Reports Server (NTRS)

Kurkov, A. P.

1984-01-01

Analytic representations are developed for the discrete blade deflection and the continuous tip static pressure fields in a stationary reference frame. Considered are the sampling rates equal to the rotational frequency, equal to blade passing frequency, and for the pressure, equal to a multiple of the blade passing frequency. For the last two rates the expressions for determining the nodal diameters from the spectra are included. A procedure is presented for transforming the complete unsteady pressure field into a rotating frame of reference. The determination of the true flutter frequency by using two sensors is described. To illustrate their use, the developed procedures are used to interpret selected experimental results.

A Framework for Establishing Standard Reference Scale of Texture by Multivariate Statistical Analysis Based on Instrumental Measurement and Sensory Evaluation.

PubMed

Zhi, Ruicong; Zhao, Lei; Xie, Nan; Wang, Houyin; Shi, Bolin; Shi, Jingye

2016-01-13

A framework of establishing standard reference scale (texture) is proposed by multivariate statistical analysis according to instrumental measurement and sensory evaluation. Multivariate statistical analysis is conducted to rapidly select typical reference samples with characteristics of universality, representativeness, stability, substitutability, and traceability. The reasonableness of the framework method is verified by establishing standard reference scale of texture attribute (hardness) with Chinese well-known food. More than 100 food products in 16 categories were tested using instrumental measurement (TPA test), and the result was analyzed with clustering analysis, principal component analysis, relative standard deviation, and analysis of variance. As a result, nine kinds of foods were determined to construct the hardness standard reference scale. The results indicate that the regression coefficient between the estimated sensory value and the instrumentally measured value is significant (R(2) = 0.9765), which fits well with Stevens's theory. The research provides reliable a theoretical basis and practical guide for quantitative standard reference scale establishment on food texture characteristics.

Concept of a self-pressurized feed system for liquid rocket engines and its fundamental experiment results

NASA Astrophysics Data System (ADS)

Matsumoto, Jun; Okaya, Shunichi; Igoh, Hiroshi; Kawaguchi, Junichiro

2017-04-01

A new propellant feed system referred to as a self-pressurized feed system is proposed for liquid rocket engines. The self-pressurized feed system is a type of gas-pressure feed system; however, the pressurization source is retained in the liquid state to reduce tank volume. The liquid pressurization source is heated and gasified using heat exchange from the hot propellant using a regenerative cooling strategy. The liquid pressurization source is raised to critical pressure by a pressure booster referred to as a charger in order to avoid boiling and improve the heat exchange efficiency. The charger is driven by a part of the generated pressurization gas using a closed-loop self-pressurized feed system. The purpose of this study is to propose a propellant feed system that is lighter and simpler than traditional gas pressure feed systems. The proposed system can be applied to all liquid rocket engines that use the regenerative cooling strategy. The concept and mathematical models of the self-pressurized feed system are presented first. Experiment results for verification are then shown and compared with the mathematical models.

18 CFR 38.2 - Incorporation by reference of North American Energy Standards Board Wholesale Electric Quadrant...

Code of Federal Regulations, 2011 CFR

2011-04-01

....13, 001-1.0, 001-9.7, 001-14.1.3, and 001-15.1.2); (2) Open Access Same-Time Information Systems... reference of North American Energy Standards Board Wholesale Electric Quadrant standards. 38.2 Section 38.2... UTILITIES § 38.2 Incorporation by reference of North American Energy Standards Board Wholesale Electric...

USAF bioenvironmental noise data handbook. Volume 157: KC-10A in-flight crew noise

NASA Astrophysics Data System (ADS)

Hille, H. K.

1982-09-01

The KC-10A is a standard USAF tanker-transport aircraft with high-speed, high altitude refueling and long range transport capability. This report provides measured data defining the bioacoustic environments at flight crew/passenger locations inside this helicopter during normal flight operations. Data are reported for 24 locations in a wide variety of physical and psychoacoustic measures: overall and band sound pressure levels, C-weighted and A-weighted sound levels, preferred speech interference level, perceived noise level, and limiting times for total daily exposure of personnel with and without standard Air Force ear protectors. Refer to Volume 1 of this handbook, USAF Bioenvironmental Noise Data Handbook, Vol. 1: Organization, Content and Application, AMRL-TR-75-50(1) 1975, for discussion of the objective and design of the handbook, the types of data presented, measurement procedures, instrumentation, data processing, definitions of quantities, symbols, equations, applications, limitations, etc.

Detonation Products EOS by Specifying Gamma (V) for the Principal Isentrope

NASA Astrophysics Data System (ADS)

Partom, Yehuda

2011-07-01

The standard way of defining an equation of state (EOS) for detonation products is (1) choose a function Ps(V) for the pressure along the principal isentrope, with enough adjustable parameters; (2) integrate it to obtain the internal energy Es(V); (3) determine the parameters from available data (Chapman Jouget (CJ) state and cylinder expansion test); (4) refer a Gruneisen EOS to this principal isentrope. Using this approach, (1) most of the adjustable parameters have no physical meaning; (2) they are determined simultaneously; and (3) changing one of them requires changing the others. Instead, we define the principal isentrope by choosing a function for the adiabatic gamma γs(V). We show that this has the following advantages over the standard approach: (1) the parameters have physical meaning; (2) they can be determined by a recursive process; (3) the influence of changes in the parameters to cylinder expansion results is obvious.

Towards a Framework for Developing Semantic Relatedness Reference Standards

PubMed Central

Pakhomov, Serguei V.S.; Pedersen, Ted; McInnes, Bridget; Melton, Genevieve B.; Ruggieri, Alexander; Chute, Christopher G.

2010-01-01

Our objective is to develop a framework for creating reference standards for functional testing of computerized measures of semantic relatedness. Currently, research on computerized approaches to semantic relatedness between biomedical concepts relies on reference standards created for specific purposes using a variety of methods for their analysis. In most cases, these reference standards are not publicly available and the published information provided in manuscripts that evaluate computerized semantic relatedness measurement approaches is not sufficient to reproduce the results. Our proposed framework is based on the experiences of medical informatics and computational linguistics communities and addresses practical and theoretical issues with creating reference standards for semantic relatedness. We demonstrate the use of the framework on a pilot set of 101 medical term pairs rated for semantic relatedness by 13 medical coding experts. While the reliability of this particular reference standard is in the “moderate” range; we show that using clustering and factor analyses offers a data-driven approach to finding systematic differences among raters and identifying groups of potential outliers. We test two ontology-based measures of relatedness and provide both the reference standard containing individual ratings and the R program used to analyze the ratings as open-source. Currently, these resources are intended to be used to reproduce and compare results of studies involving computerized measures of semantic relatedness. Our framework may be extended to the development of reference standards in other research areas in medical informatics including automatic classification, information retrieval from medical records and vocabulary/ontology development. PMID:21044697

Inconsistency between simultaneous blood pressure measurements in the arm, forearm, and leg in anesthetized children.

PubMed

Keidan, Ilan; Sidi, Avner; Ben-Menachem, Erez; Tene, Yael; Berkenstadt, Haim

2014-02-01

To determine the accuracy and precision of simultaneous noninvasive blood pressure (NIBP) measurement in the arm, forearm, and ankle in anesthetized children. Prospective, randomized study. University medical center. 101 ASA physical status 1 and 2 children (aged 1-8 yrs) scheduled for elective surgery with general anesthesia. Simultaneous NIBP measurements were recorded at the arm, forearm, and ankle at 5-minute intervals. The systolic blood pressure difference between the arm-forearm or the arm-ankle was within the ± 10% range in 63% and 29% of measurements, and within the ± 20% range in 85% and 67% of measurements, respectively. The diastolic blood pressure difference between the arm-forearm or the arm-ankle was within the ± 10% range in 42% and 44% and within the ± 20% range in 67% and 74% of measurements, respectively. In patients in whom the initial three NIBP measurements were within the ± 20% range between the forearm and arm, 86% of the subsequent measurements were also within that limit. Forearm and ankle NIBP measurements are unreliable and inconsistent with NIBP measured in the arm of anesthetized children. These alternative BP measurement sites are not reliable in accuracy (comparison with reference "gold" standard) and precision (reproducibility). Copyright © 2014 Elsevier Inc. All rights reserved.

Halogenated methyl-phenyl ethers (anisoles) in the environment: determination of vapor pressures, aqueous solubilities, Henry's law constants, and gas/water- (Kgw), n-octanol/water- (Kow) and gas/n-octanol (Kgo) partition coefficients.

PubMed

Pfeifer, O; Lohmann, U; Ballschmiter, K

2001-11-01

Halogenated methyl-phenyl ethers (methoxybenzenes, anisoles) are ubiquitous organics in the environment although they are not produced in industrial quantities. Modelling the fate of organic pollutants such as halogenated anisoles requires a knowledge of the fundamental physico-chemical properties of these compounds. The isomer-specific separation and detection of 60 of the 134 possible congeners allowing an environmental fingerprinting are reported in this study. The vapor pressure p0(L) of more than 60 and further physico-chemical properties of 26 available congeners are given. Vapor pressures p0(L), water solubilities S(L)W, and n-octanol/water partition coefficients Kow were determined by capillary HR-GC (High Resolution Gas Chromatography) on a non-polar phase and by RP-HPLC (Reversed Phase High Performance Liquid Chromatography) on a C18 phase with chlorobenzenes as reference standards. From these experimental data the Henry's law constants H, and the gas/water Kgw and gas/n-octanol Kgo partition coefficients were calculated. We found that vapor pressures, water solubilities, and n-octanol/water partition coefficients of the halogenated anisoles are close to those of the chlorobenzenes. A similar environmental fate of both groups can, therefore, be predicted.

A prospective double-blinded randomized controlled trial comparing systemic stress response in Laparoascopic cholecystectomy between low-pressure and standard-pressure pneumoperitoneum.

PubMed

Shoar, Saeed; Naderan, Mohammad; Ebrahimpour, Hossein; Soroush, Ahmadreza; Nasiri, Shirzad; Movafegh, Ali; Khorgami, Zhamak

2016-04-01

Laparoscopic cholecystectomy (LC) has become the gold-standard treatment for gallstone diseases. However, despite huge reduction in operative injury, systemic stress response remains high. This randomized controlled trial (RCT) aimed to compare systemic stress response between 2 different techniques of CO2 pneumoperitoneum. Trough a prospective, double-blinded RCT, serum levels of cortisol, adrenaline, glucose, and C-reactive protein (CRP) were compared between the two groups consisted of 50 patients undergoing LC under low-pressure and standard-pressure CO2 pneimoperitoneum. A total of fifty patients undergoing LC were equally assigned to 2 groups of twenty five patients. Average age was 48 ± 13.8 years (range, 19-74 years). Operative time was similar between standard-pressure group (47.8 ± 16.8 min) and low-pressure group (53.6 ± 25.1). Moreover, intra-operative IV volume administration and urine output did not differ significantly between the 2 groups (p > 0.05). Although the average heart rate and mean arterial pressure were slightly higher in a standard-pressure group compared with a low-pressure group, serial measurements of these parameters were statistically similar between the 2 groups. Serial changes of serum levels of cortisol, glucose, adrenaline, and CRP were compared between surgery day, postoperative 6-h and 1st postoperative day, which did not differ significantly between the standard-pressure and the low-pressure groups (p > 0.05). Our study did not reveal any alteration in systemic stress response with reduction in intra-abdominal pressure of pneumoperitoneum in LC. RCT REGISTRATION: irct.ir ID: IRCT201110072982N5. Copyright © 2016 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

ACIST-FFR Study (Assessment of Catheter-Based Interrogation and Standard Techniques for Fractional Flow Reserve Measurement)

PubMed Central

Chambers, Jeffrey W.; Seto, Arnold H.; Sarembock, Ian J.; Raveendran, Ganesh; Sakarovitch, Charlotte; Yang, Lingyao; Desai, Manisha; Jeremias, Allen; Price, Matthew J.

2017-01-01

Background— Measurement of fractional flow reserve (FFR) to guide coronary revascularization lags despite robust supportive data, partly because of the handling characteristics of traditional coronary pressure wires. An optical pressure-monitoring microcatheter, which can be advanced over a traditional coronary guidewire, facilitates FFR assessment but may underestimate pressure wire–derived FFR. Methods and Results— In this prospective, multicenter trial, 169 patients underwent FFR assessment with a pressure wire alone and with a pressure microcatheter over the pressure wire. An independent core laboratory performed quantitative coronary angiography and evaluated all pressure tracings. The primary end point was the bias or difference between the microcatheter FFR and the pressure wire FFR, as assessed by Bland–Altman analysis. The mean difference between the microcatheter and the pressure wire–derived FFR values was −0.022 (95% confidence interval, −0.029 to −0.015). On multivariable analysis, reference vessel diameter (P=0.027) and lesion length (P=0.044) were independent predictors of bias between the 2 FFR measurements. When the microcatheter FFR was added to this model, it was the only independent predictor of bias (P<0.001). The mean FFR value from the microcatheter was significantly lower than from the pressure wire (0.81 versus 0.83; P<0.001). In 3% of cases (95% confidence interval, 1.3%–6.7%), there was clinically meaningful diagnostic discordance, with the FFR from the pressure wire >0.80 and that from the microcatheter <0.75. These findings were similar when including all 210 patients with site-reported paired FFR data. Conclusions— An optical, pressure-monitoring microcatheter measures lower FFR compared with a pressure wire, but the diagnostic impact appears to be minimal in most cases. Clinical Trial Registration— URL: https://www.clinicaltrials.gov. Unique identifier: NCT02577484. PMID:29246917

Hg0 and HgCl2 Reference Gas Standards: ?NIST Traceability ...

EPA Pesticide Factsheets

EPA and NIST have collaborated to establish the necessary procedures for establishing the required NIST traceability of commercially-provided Hg0 and HgCl2 reference generators. This presentation will discuss the approach of a joint EPA/NIST study to accurately quantify the true concentrations of Hg0 and HgCl2 reference gases produced from high quality, NIST-traceable, commercial Hg0 and HgCl2 generators. This presentation will also discuss the availability of HCl and Hg0 compressed reference gas standards as a result of EPA's recently approved Alternative Methods 114 and 118. Gaseous elemental mercury (Hg0) and oxidized mercury (HgCl2) reference standards are integral to the use of mercury continuous emissions monitoring systems (Hg CEMS) for regulatory compliance emissions monitoring. However, a quantitative disparity of approximately 7-10% has been observed between commercial Hg0 and HgCl2 reference gases which currently limits the use of (HgCl2) reference gas standards. Resolving this disparity would enable the expanded use of (HgCl2) reference gas standards for regulatory compliance purposes.

75 FR 69052 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-10

... seamless carbon and alloy steel standard, line, and pressure pipe (``seamless pipe'') from the People's... seamless pipe from the PRC. See Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe..., and its negative determination of critical circumstances. See Certain Seamless Carbon and Alloy Steel...

77 FR 59374 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe (Under 41/2

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-27

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-851] Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe (Under 4\\1/2\\ Inches) From Japan: Rescission... antidumping order on certain small diameter carbon and alloy seamless standard, line and pressure pipe (under...

75 FR 9163 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-01

... Alloy Steel Standard, Line, and Pressure Pipe From the People's Republic of China: Preliminary... the People's Republic of China. For information on the estimated subsidy rates, see the ``Suspension... Carbon and Alloy Steel Standard, Line, and Pressure Pipe from the People's Republic of China: Initiation...

Two Primary Standards for Low Flows of Gases

PubMed Central

Berg, Robert F.; Tison, Stuart A.

2004-01-01

We describe two primary standards for gas flow in the range from 0.1 to 1000 μmol/s. (1 μmol/s ≅ 1.3 cm3/min at 0 °C and 1 atmosphere.) The first standard is a volumetric technique in which measurements of pressure, volume, temperature, and time are recorded while gas flows in or out of a stainless steel bellows at constant pressure. The second standard is a gravimetric technique. A small aluminum pressure cylinder supplies gas to a laminar flow meter, and the integrated throughput of the laminar flow meter is compared to the weight decrease of the cylinder. The two standards, which have standard uncertainties of 0.019 %, agree to within combined uncertainties with each other and with a third primary standard at NIST based on pressure measurements at constant volume. PMID:27366623

Relationship between Food Security with Sugar Level and Blood Pressure in Diabetes Type 2 in Tehran.

PubMed

Moghadam, Seyed Amir Hossein Zehni; Javadi, Maryam; Mohammadpooral, Asghar

2016-12-01

Food security has been defined as the "availability, stability, access and utilization of safe foods". Diabetes has been known as one of the biggest health and medical problems throughout the world and is clearly related to lifestyle, and particularly, improper food consumption. The aim of this study was to determine the relationship between food security with sugar and blood pressure in patients suffering from type 2 diabetes who refer to diabetes centers in Tehran. This cross-sectional study was conducted in 2015 on type 2 diabetes patients in Tehran, Iran. From two diabetes centers in the eastern and southern parts of Tehran, 243 type 2 diabetes patients were selected. Necessary information (demographic and food security information) about all the studied persons was collected using the standard questionnaire verified by US Department of Agriculture (USDA). The data was analyzed by SPSS version 16, statistical comparisons were made using analysis of variance (ANOVA) and Chi-square and Tukey tests and a significant level of <0.05. Most subjects were female (68.7%). There was no significant relationship between gender and food security (p=0.372). No significant relation was observed between food security and fasting blood pressure, HbA1C, and systolic blood pressure (p>0.05), but there was a significant relationship between food security and diastolic blood pressure (p= 0.030). According to the relationship between diastolic blood pressure and food security and the role of blood pressure in the irreparable diabetic complications, it is recommended to perform appropriate food advice.

On-line calibration of high-response pressure transducers during jet-engine testing

NASA Technical Reports Server (NTRS)

Armentrout, E. C.

1974-01-01

Jet engine testing is reported concerned with the effect of inlet pressure and temperature distortions on engine performance and involves the use of numerous miniature pressure transducers. Despite recent improvements in the manufacture of miniature pressure transducers, they still exhibit sensitivity change and zero-shift with temperature and time. To obtain meaningful data, a calibration system is needed to determine these changes. A system has been developed which provides for computer selection of appropriate reference pressures selected from nine different sources to provide a two- or three-point calibration. Calibrations are made on command, before and sometimes after each data point. A unique no leak matrix valve design is used in the reference pressure system. Zero-shift corrections are measured and the values are automatically inserted into the data reduction program.

Effects of non-tidal atmospheric loading on a Kalman filter-based terrestrial reference frame

NASA Astrophysics Data System (ADS)

Abbondanza, C.; Altamimi, Z.; Chin, T. M.; Collilieux, X.; Dach, R.; Heflin, M. B.; Gross, R. S.; König, R.; Lemoine, F. G.; MacMillan, D. S.; Parker, J. W.; van Dam, T. M.; Wu, X.

2013-12-01

The International Terrestrial Reference Frame (ITRF) adopts a piece-wise linear model to parameterize regularized station positions and velocities. The space-geodetic (SG) solutions from VLBI, SLR, GPS and DORIS global networks used as input in the ITRF combination process account for tidal loading deformations, but ignore the non-tidal part. As a result, the non-linear signal observed in the time series of SG-derived station positions in part reflects non-tidal loading displacements not introduced in the SG data reduction. In this analysis, the effect of non-tidal atmospheric loading (NTAL) corrections on the TRF is assessed adopting a Remove/Restore approach: (i) Focusing on the a-posteriori approach, the NTAL model derived from the National Center for Environmental Prediction (NCEP) surface pressure is removed from the SINEX files of the SG solutions used as inputs to the TRF determinations. (ii) Adopting a Kalman-filter based approach, a linear TRF is estimated combining the 4 SG solutions free from NTAL displacements. (iii) Linear fits to the NTAL displacements removed at step (i) are restored to the linear reference frame estimated at (ii). The velocity fields of the (standard) linear reference frame in which the NTAL model has not been removed and the one in which the model has been removed/restored are compared and discussed.

Reevaluation of the NOAA/CMDL carbon monoxide reference scale and comparisons with CO reference gases at NASA-Langley and the Fraunhofer Institut

NASA Technical Reports Server (NTRS)

Novelli, P. C.; Collins, J. E., Jr.; Myers, R. C.; Sachse, G. W.; Scheel, H. E.

1994-01-01

The carbon monoxide (CO) reference scale created by the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) is used to quantify measurements of CO in the atmosphere, calibrate standards of other laboratories and to otherwise provide reference gases to the community measuring atmospheric CO. This reference scale was created based upon a set of primary standards prepared by gravimetric methods at CMDL and has been propagated to a set of working standards. In this paper we compare CO mixing ratios assigned to the working standards by three approaches: (1) calibration against the original gravimetric standards, (2) calibration using only working standards as the reference gas, and (3) calibration against three new gravimetric standards prepared to CMDL. The agreement between these values was typically better than 1%. The calibration histories of CMDL working standards are reviewed with respect to expected rates of CO change in the atmosphere. Using a Monte Carlo approach to simulate the effect of drifting standards on calculated mixing ratios, we conclude that the error solely associated with the maintenance of standards will limit the ability to detect small CO changes in the atmosphere. We also report results of intercalibration experiments conducted between CMDL and the Diode Laser Sensor Group (DACOM) at the NASA Langley Research Center (Hampton, Virginia), and CMDL and the Fraunhofer-Institut (Garmisch-Partenkirchen, Germany). Each laboratory calibrated several working standards for CO using their reference gases, and these results were compared to calibrations conducted by CMDL. The intercomparison of eight standards (CO concentrations between approximately 100 and approximately 165 ppb) by CMDL and NASA agreed to better than +/- 2%. The calibration of six standards (CO concentrations between approximately 50 and approximately 210 ppb) by CMDL and the Fraunhofer-Institut agreed to within +/- 2% for four standards, and to within +/- 5% for all six standards.

A prospective randomized study of systemic inflammation and immune response after laparoscopic nissen fundoplication performed with standard and low-pressure pneumoperitoneum.

PubMed

Schietroma, Mario; Carlei, Francesco; Cecilia, Emanuela M; Piccione, Federica; Sista, Federico; De Vita, Fabiola; Amicucci, Gianfranco

2013-04-01

The aim of this study was to compare changes in the systemic inflammation and immune response in the early postoperative (p.o.) period after laparoscopic Nissen fundoplication (LNF) was performed with standard-pressure and low-pressure carbon dioxide pneumoperitoneum. We studied 68 patients with documented gastroesophageal reflux disease and who underwent a LNF: 35 using standard-pressure (12 to 14 mmHg) and 33 low-pressure (6 to 8 mmHg) pneumoperitoneum. White blood cells, peripheral lymphocytes subpopulation, human leukocyte antigen-DR, neutrophil elastase, interleukin (IL)-6 and IL-1, and C-reactive protein were investigated. A significantly higher concentration of neutrophil elastase, IL-6 and IL-1, and C-reactive protein was detected postoperatively in the standard-pressure group of patients in comparison with the low-pressure group (P<0.05). A statistically significant change in human leukocyte antigen-DR expression was recorded p.o. at 24 hours, as a reduction of this antigen expressed on monocyte surface in patients from standard group; no changes were noted in low-pressure group patients (P<0.05). This study demonstrated that reducing the pressure of the pneumoperitoneum to 6 to 8 mm Hg during LNF is reduced p.o. inflammatory response and avoided p.o. immunosuppression.

22 CFR 705.101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Cross-reference to employee ethical conduct... INVESTMENT CORPORATION ADMINISTRATIVE PROVISIONS EMPLOYEE ETHICAL CONDUCT STANDARDS AND FINANCIAL DISCLOSURE REGULATIONS § 705.101 Cross-reference to employee ethical conduct standards and financial disclosure...

Certification of elements in and use of standard reference material 3280 multivitamin/multielement tablets

USDA-ARS?s Scientific Manuscript database

Standard Reference Material (SRM) 3280 Multivitamin/Multielement Tablets was issued by the National Institute of Standards and Technology (NIST) in 2009 and has certified and reference mass fraction values for 13 vitamins, 26 elements, and 2 carotenoids. Elements were measured using two or more ana...

22 CFR 705.101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Cross-reference to employee ethical conduct... INVESTMENT CORPORATION ADMINISTRATIVE PROVISIONS EMPLOYEE ETHICAL CONDUCT STANDARDS AND FINANCIAL DISCLOSURE REGULATIONS § 705.101 Cross-reference to employee ethical conduct standards and financial disclosure...

22 CFR 705.101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Cross-reference to employee ethical conduct... INVESTMENT CORPORATION ADMINISTRATIVE PROVISIONS EMPLOYEE ETHICAL CONDUCT STANDARDS AND FINANCIAL DISCLOSURE REGULATIONS § 705.101 Cross-reference to employee ethical conduct standards and financial disclosure...

22 CFR 705.101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Cross-reference to employee ethical conduct... INVESTMENT CORPORATION ADMINISTRATIVE PROVISIONS EMPLOYEE ETHICAL CONDUCT STANDARDS AND FINANCIAL DISCLOSURE REGULATIONS § 705.101 Cross-reference to employee ethical conduct standards and financial disclosure...

22 CFR 705.101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Cross-reference to employee ethical conduct... INVESTMENT CORPORATION ADMINISTRATIVE PROVISIONS EMPLOYEE ETHICAL CONDUCT STANDARDS AND FINANCIAL DISCLOSURE REGULATIONS § 705.101 Cross-reference to employee ethical conduct standards and financial disclosure...

Agreement between diagnoses reached by clinical examination and available reference standards: a prospective study of 216 patients with lumbopelvic pain

PubMed Central

Laslett, Mark; McDonald, Barry; Tropp, Hans; Aprill, Charles N; Öberg, Birgitta

2005-01-01

Background The tissue origin of low back pain (LBP) or referred lower extremity symptoms (LES) may be identified in about 70% of cases using advanced imaging, discography and facet or sacroiliac joint blocks. These techniques are invasive and availability varies. A clinical examination is non-invasive and widely available but its validity is questioned. Diagnostic studies usually examine single tests in relation to single reference standards, yet in clinical practice, clinicians use multiple tests and select from a range of possible diagnoses. There is a need for studies that evaluate the diagnostic performance of clinical diagnoses against available reference standards. Methods We compared blinded clinical diagnoses with diagnoses based on available reference standards for known causes of LBP or LES such as discography, facet, sacroiliac or hip joint blocks, epidurals injections, advanced imaging studies or any combination of these tests. A prospective, blinded validity design was employed. Physiotherapists examined consecutive patients with chronic lumbopelvic pain and/or referred LES scheduled to receive the reference standard examinations. When diagnoses were in complete agreement regardless of complexity, "exact" agreement was recorded. When the clinical diagnosis was included within the reference standard diagnoses, "clinical agreement" was recorded. The proportional chance criterion (PCC) statistic was used to estimate agreement on multiple diagnostic possibilities because it accounts for the prevalence of individual categories in the sample. The kappa statistic was used to estimate agreement on six pathoanatomic diagnoses. Results In a sample of chronic LBP patients (n = 216) with high levels of disability and distress, 67% received a patho-anatomic diagnosis based on available reference standards, and 10% had more than one tissue origin of pain identified. For 27 diagnostic categories and combinations, chance clinical agreement (PCC) was estimated at 13%. "Exact" agreement between clinical and reference standard diagnoses was 32% and "clinical agreement" 51%. For six pathoanatomic categories (disc, facet joint, sacroiliac joint, hip joint, nerve root and spinal stenosis), PCC was 33% with actual agreement 56%. There was no overlap of 95% confidence intervals on any comparison. Diagnostic agreement on the six most common patho-anatomic categories produced a kappa of 0.31. Conclusion Clinical diagnoses agree with reference standards diagnoses more often than chance. Using available reference standards, most patients can have a tissue source of pain identified. PMID:15943873

Alternative mass reference standards for direct analysis in real time mass spectrometry.

PubMed

Cody, Robert B; Dane, A John

2016-05-30

Mass spectra were acquired with the Direct Analysis in Real Time (DART®) ion source for an amine-terminated polyether used as positive-ion mass reference standards and for several fluorinated materials commonly used as negative-ion reference standards for mass spectrometry. A commercial time-of-flight mass spectrometer equipped with a DART ion source was used for all measurements. Mass reference standards deposited onto the sealed end of a glass melting point tube were suspended in the DART gas stream for analysis. A polyetheramine (Jeffamine® M-600) produced intense peaks corresponding to protonated molecules. Perfluorotributylamine (PFTBA), and perfluorotripentylamine, gave useful reference spectra for different m/z ranges. DART mass spectra of Ultramark 1621® resembled those previously reported for Fast Atom Bombardment (FAB) and Electrospray Ionization (ESI). Fomblin®Y, a fluorinated ether, was the most useful negative-ion reference standard of the materials tested. The material is commercially available, inexpensive, and provides reference peaks covering the m/z range 85 to >3000. Jeffamine-M600 was found to be a convenient alternative to polyethers such as polyethylene glycol (PEG) for DART positive-ion mass calibration. Fomblin Y was suitable for use as a negative-ion reference standard. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Options for Dealing with Pressure Dependence of Pulse Wave Velocity as a Measure of Arterial Stiffness: An Update of Cardio-Ankle Vascular Index (CAVI) and CAVI0.

PubMed

Spronck, Bart; Delhaas, Tammo; Butlin, Mark; Reesink, Koen D; Avolio, Alberto P

2018-03-01

Pulse wave velocity (PWV), a marker of arterial stiffness, is known to change instantaneously with changes in blood pressure. In this mini-review, we discuss two main approaches for handling the blood pressure dependence of PWV: (1) converting PWV into a pressure-independent index, and (2) correcting PWV per se for the pressure dependence. Under option 1, we focus on cardio-ankle vascular index (CAVI). CAVI is essentially a form of stiffness index β - CAVI is estimated for a (heart-to-ankle) trajectory, whereas β is estimated for a single artery from pressure and diameter measurements. Stiffness index β, and therefore also CAVI, have been shown to theoretically exhibit a slight residual blood pressure dependence due to the use of diastolic blood pressure instead of a fixed reference blood pressure. Additionally, CAVI exhibits pressure dependence due to the use of an estimated derivative of the pressure-diameter relationship. In this mini-review, we will address CAVI's blood pressure dependence theoretically, but also statistically. Furthermore, we review corrected indices (CAVI 0 and β 0 ) that theoretically do not show a residual blood pressure dependence. Under option 2, three ways of correcting PWV are reviewed: (1) using an exponential relationship between pressure and cross-sectional area, (2) by statistical model adjustment, and (3) through reference values or rule of thumb. Method 2 requires a population to be studied to characterise the statistical model, and method 3 requires a representative reference study. Given these limitations, method 1 seems preferable for correcting PWV per se for its blood pressure dependence. In summary, several options are available to handle the blood pressure dependence of PWV. If a blood pressure-independent index is sought, CAVI 0 is theoretically preferable over CAVI. If correcting PWV per se is required, using an exponential pressure-area relationship provides the user with a method to correct PWV on an individual basis.

Updating OSHA standards based on national consensus standards. Direct final rule.

PubMed

2007-12-14

In this direct final rule, the Agency is removing several references to consensus standards that have requirements that duplicate, or are comparable to, other OSHA rules; this action includes correcting a paragraph citation in one of these OSHA rules. The Agency also is removing a reference to American Welding Society standard A3.0-1969 ("Terms and Definitions") in its general-industry welding standards. This rulemaking is a continuation of OSHA's ongoing effort to update references to consensus and industry standards used throughout its rules.

Optical-Fiber Power Meter Comparison between NIST and KRISS.

PubMed

Vayshenker, I; Kim, S K; Hong, K; Lee, D-H; Livigni, D J; Li, X; Lehman, J H

2012-01-01

We describe the results of a comparison of reference standards between the National Institute of Standards and Technology (NIST-USA) and Korea Research Institute of Standards and Science (KRISS-R.O. Korea) for optical fiber-based power measurements at wavelengths of 1302 nm and 1546 nm. We compare the laboratories' reference standards by means of a temperature-controlled optical trap detector. Measurement results showed the largest difference of less than 2.5 parts in 10(3), which is within the combined standard (k=1) uncertainty for the two laboratories' reference standards.

77 FR 43806 - Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's Republic of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-26

... duty order on seamless carbon and alloy steel standard, line, and pressure pipe from the People's... the antidumping duty order on seamless carbon and alloy steel standard, line, and pressure pipe from... Making Co., Ltd.; Wuxi Seamless Special Pipe Co., Ltd.; Wuxi Sifang Steel Tube Co., Ltd.; Wuxi Zhenda...

78 FR 41366 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 4 1/2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-10

... Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 4 \\1/2\\ Inches) From Japan: Preliminary... seamless standard, line, and pressure pipe (over 4 \\1/2\\ inches) (large diameter seamless pipe) from Japan.../exporters of subject merchandise, Canadian Natural Resources Limited (CNRL), JFE Steel Corporation (JFE...

77 FR 67336 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-09

... products subject to the order are small diameter seamless carbon and alloy (other than stainless) steel... Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania: Final Results of Antidumping... alloy seamless standard, line and pressure pipe from Romania. The period of review is August 1, 2010...

78 FR 33809 - Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's Republic of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... review of the antidumping duty order on seamless carbon and alloy steel standard, line, and pressure pipe... seamless carbon and alloy steel standard, line, and pressure pipe from the People's Republic of China... DEPARTMENT OF COMMERCE International Trade Administration [A-570-956] Seamless Carbon and Alloy...

77 FR 181 - Federal Acquisition Regulation; Federal Acquisition Circular 2005-55; Introduction

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-03

... System. VI Updated Financial 2010-005 Chambers. Accounting Standards Board Accounting References. VII... Financial Accounting Standards Board Accounting References (FAR Case 2010-005) This final rule amends the... authoritative accounting standards owing to the Financial Accounting Standards Board's Accounting Standards...

10 CFR 50.150 - Aircraft impact assessment.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 13, 2009; (B) Renewal of standard design certifications in effect on July 13, 2009 which have not..., standard design approval, or manufactured reactor; or (B) Reference a standard design certification issued... certification or standard design approval; or (B) Reference a standard design certification issued before July...

10 CFR 50.150 - Aircraft impact assessment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 13, 2009; (B) Renewal of standard design certifications in effect on July 13, 2009 which have not..., standard design approval, or manufactured reactor; or (B) Reference a standard design certification issued... certification or standard design approval; or (B) Reference a standard design certification issued before July...

10 CFR 50.150 - Aircraft impact assessment.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 13, 2009; (B) Renewal of standard design certifications in effect on July 13, 2009 which have not..., standard design approval, or manufactured reactor; or (B) Reference a standard design certification issued... certification or standard design approval; or (B) Reference a standard design certification issued before July...

10 CFR 50.150 - Aircraft impact assessment.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 13, 2009; (B) Renewal of standard design certifications in effect on July 13, 2009 which have not..., standard design approval, or manufactured reactor; or (B) Reference a standard design certification issued... certification or standard design approval; or (B) Reference a standard design certification issued before July...

Pressure ulcer treatment strategies: a systematic comparative effectiveness review.

PubMed

Smith, M E Beth; Totten, Annette; Hickam, David H; Fu, Rongwei; Wasson, Ngoc; Rahman, Basmah; Motu'apuaka, Makalapua; Saha, Somnath

2013-07-02

Pressure ulcers affect as many as 3 million Americans and are major sources of morbidity, mortality, and health care costs. To summarize evidence comparing the effectiveness and safety of treatment strategies for adults with pressure ulcers. MEDLINE, EMBASE, CINAHL, Evidence-Based Medicine Reviews, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, and Health Technology Assessment Database for English- or foreign-language studies; reference lists; gray literature; and individual product packets from manufacturers (January 1985 to October 2012). Randomized trials and comparative observational studies of treatments for pressure ulcers in adults and noncomparative intervention series (n > 50) for surgical interventions and evaluation of harms. Data were extracted and evaluated for accuracy of the extraction, quality of included studies, and strength of evidence. 174 studies met inclusion criteria and 92 evaluated complete wound healing. In comparison with standard care, placebo, or sham interventions, moderate-strength evidence showed that air-fluidized beds (5 studies [n = 908]; high consistency), protein-containing nutritional supplements (12 studies [n = 562]; high consistency), radiant heat dressings (4 studies [n = 160]; moderate consistency), and electrical stimulation (9 studies [n = 397]; moderate consistency) improved healing of pressure ulcers. Low-strength evidence showed that alternating-pressure surfaces, hydrocolloid dressings, platelet-derived growth factor, and light therapy improved healing of pressure ulcers. The evidence about harms was limited. Applicability of results is limited by study quality, heterogeneity in methods and outcomes, and inadequate duration to assess complete wound healing. Moderate-strength evidence shows that healing of pressure ulcers in adults is improved with the use of air-fluidized beds, protein supplementation, radiant heat dressings, and electrical stimulation.

46 CFR 197.204 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Institute “Code for Pressure Piping, Power Piping.” ASME Code means the American Society of Mechanical Engineers “Boiler and Pressure Vessel Code.” ASME PVHO-1 means the ANSI/ASME standard “Safety Standard for Pressure Vessels for Human Occupancy.” ATA means a measure of pressure expressed in terms of atmosphere...

46 CFR 197.204 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Institute “Code for Pressure Piping, Power Piping.” ASME Code means the American Society of Mechanical Engineers “Boiler and Pressure Vessel Code.” ASME PVHO-1 means the ANSI/ASME standard “Safety Standard for Pressure Vessels for Human Occupancy.” ATA means a measure of pressure expressed in terms of atmosphere...

46 CFR 197.204 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Institute “Code for Pressure Piping, Power Piping.” ASME Code means the American Society of Mechanical Engineers “Boiler and Pressure Vessel Code.” ASME PVHO-1 means the ANSI/ASME standard “Safety Standard for Pressure Vessels for Human Occupancy.” ATA means a measure of pressure expressed in terms of atmosphere...

46 CFR 197.204 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Institute “Code for Pressure Piping, Power Piping.” ASME Code means the American Society of Mechanical Engineers “Boiler and Pressure Vessel Code.” ASME PVHO-1 means the ANSI/ASME standard “Safety Standard for Pressure Vessels for Human Occupancy.” ATA means a measure of pressure expressed in terms of atmosphere...

Characteristics of precision 1 Ω standard resistors influencing transport behaviour and the uncertainty of key comparisons

NASA Astrophysics Data System (ADS)

Jones, G. R.; Pritchard, B. J.; Elmquist, R. E.

2009-10-01

National measurement institutes (NMIs) participate in international key comparisons organized by the Bureau International des Poids et Mesures (BIPM), the Regional Metrology Organizations (RMOs) or the Consultative Committees of the Comité International des Poids et Mesures (CIPM) in order to provide evidence of equivalent reference standards and measurement capabilities. The US National Institute of Standards and Technology (NIST) and the National Measurement Institute of Australia (NMIA) have recently examined power loading and several other influences on the value of precision transportable 1 Ω resistors that can increase the uncertainty of key comparisons. We have studied the effects of temperature, barometric pressure, humidity, power loading and heat dissipation in oil on transportable wire-wound 1 Ω resistance standards that are based on different alloys and construction principles. This work focuses on standards manufactured from 1970 through 2000 by the NMIA made of Evanohm alloy and on Thomas-type resistors designed in the 1930s and made of Manganin alloy. We show that the relative standard uncertainty related to transport can be less than 0.01 μΩ Ω-1 when using certain resistors of these two types that are characterized and selected for stability. We describe the characterization process, and relate the environmental influences to the physical design, as well as to the mechanical properties and condition of the standards.

Optical Fiber Power Meter Comparison Between NIST and NIM.

PubMed

Vayshenker, I; Livigni, D J; Li, X; Lehman, J H; Li, J; Xiong, L M; Zhang, Z X

2010-01-01

We describe the results of a comparison of reference standards between the National Institute of Standards and Technology (NIST-USA) and National Institute of Metrology (NIM-China). We report optical fiber-based power measurements at nominal wavelengths of 1310 nm and 1550 nm. We compare the laboratories' reference standards by means of a commercial optical power meter. Measurement results showed the largest difference of less than 2.6 parts in 10(3), which is within the combined standard (k = 1) uncertainty for the laboratories' reference standards.

Pressure Ratio to Thermal Environments

NASA Technical Reports Server (NTRS)

Lopez, Pedro; Wang, Winston

2012-01-01

A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

Towards a framework for developing semantic relatedness reference standards.

PubMed

Pakhomov, Serguei V S; Pedersen, Ted; McInnes, Bridget; Melton, Genevieve B; Ruggieri, Alexander; Chute, Christopher G

2011-04-01

Our objective is to develop a framework for creating reference standards for functional testing of computerized measures of semantic relatedness. Currently, research on computerized approaches to semantic relatedness between biomedical concepts relies on reference standards created for specific purposes using a variety of methods for their analysis. In most cases, these reference standards are not publicly available and the published information provided in manuscripts that evaluate computerized semantic relatedness measurement approaches is not sufficient to reproduce the results. Our proposed framework is based on the experiences of medical informatics and computational linguistics communities and addresses practical and theoretical issues with creating reference standards for semantic relatedness. We demonstrate the use of the framework on a pilot set of 101 medical term pairs rated for semantic relatedness by 13 medical coding experts. While the reliability of this particular reference standard is in the "moderate" range; we show that using clustering and factor analyses offers a data-driven approach to finding systematic differences among raters and identifying groups of potential outliers. We test two ontology-based measures of relatedness and provide both the reference standard containing individual ratings and the R program used to analyze the ratings as open-source. Currently, these resources are intended to be used to reproduce and compare results of studies involving computerized measures of semantic relatedness. Our framework may be extended to the development of reference standards in other research areas in medical informatics including automatic classification, information retrieval from medical records and vocabulary/ontology development. Copyright © 2010 Elsevier Inc. All rights reserved.

Spontaneous ignition temperature limits of jet A fuel in research-combustor segment

NASA Technical Reports Server (NTRS)

Ingebo, R. D.

1974-01-01

The effects of inlet-air pressure and reference velocity on the spontaneous-ignition temperature limits of Jet A fuel were determined in a combustor segment with a primary-zone length of 0.076 m (3 in.). At a constant reference velocity of 21.4 m/sec (170 ft/sec), increasing the inlet-air pressure from 21 to 207 N/sq cm decreased the spontaneous-ignition temperature limit from approximately 700 to 555 K. At a constant inlet-air pressure of 41 N/sq cm, increasing the reference velocity from 12.2 to 30.5 m/sec increased the spontaneous-ignition temperature limit from approximately 575 to 800 K. Results are compared with other data in the literature.

Method and apparatus for monitoring oxygen partial pressure in air masks

NASA Technical Reports Server (NTRS)

Kelly, Mark E. (Inventor); Pettit, Donald R. (Inventor)

2006-01-01

Method and apparatus are disclosed for monitoring an oxygen partial pressure in an air mask and providing a tactile warning to the user. The oxygen partial pressure in the air mask is detected using an electrochemical sensor, the output signal from which is provided to a comparator. The comparator compares the output signal with a preset reference value or range of values representing acceptable oxygen partial pressures. If the output signal is different than the reference value or outside the range of values, the air mask is vibrated by a vibrating motor to alert the user to a potentially hypoxic condition.

29 CFR 2703.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 9 2011-07-01 2011-07-01 false Cross-reference to employee ethical conduct standards and...-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees... of Ethical Conduct at 5 CFR part 2635; the Commission's regulations at 5 CFR part 8401, which...

45 CFR 706.1 - Cross-references to employee ethical conduct standards, financial disclosure and financial...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Cross-references to employee ethical conduct... EMPLOYEE RESPONSIBILITIES AND CONDUCT § 706.1 Cross-references to employee ethical conduct standards... States Commission on Civil Rights are subject to the executive branch standards of ethical conduct...

45 CFR 1105.1 - Cross-reference to employee ethical conduct standards and financial disclosure and financial...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Cross-reference to employee ethical conduct... STANDARDS OF CONDUCT FOR EMPLOYEES § 1105.1 Cross-reference to employee ethical conduct standards and... ethical conduct at 5 CFR part 2635; the executive branch employees responsibilities and conduct...

49 CFR 99.735-1 - Cross-reference to ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false Cross-reference to ethical conduct standards and... Transportation EMPLOYEE RESPONSIBILITIES AND CONDUCT General § 99.735-1 Cross-reference to ethical conduct... the executive branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Department of...

39 CFR 3000.735-101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 39 Postal Service 1 2011-07-01 2011-07-01 false Cross-reference to employee ethical conduct... employee ethical conduct standards and financial disclosure regulations. Employees of the Postal Regulatory Commission (Commission) are subject and should refer to the executive branch-wide Standards of Ethical...

45 CFR 706.1 - Cross-references to employee ethical conduct standards, financial disclosure and financial...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Cross-references to employee ethical conduct... EMPLOYEE RESPONSIBILITIES AND CONDUCT § 706.1 Cross-references to employee ethical conduct standards... States Commission on Civil Rights are subject to the executive branch standards of ethical conduct...

45 CFR 1105.1 - Cross-reference to employee ethical conduct standards and financial disclosure and financial...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Cross-reference to employee ethical conduct... STANDARDS OF CONDUCT FOR EMPLOYEES § 1105.1 Cross-reference to employee ethical conduct standards and... ethical conduct at 5 CFR part 2635; the executive branch employees responsibilities and conduct...

49 CFR 99.735-1 - Cross-reference to ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Cross-reference to ethical conduct standards and... Transportation EMPLOYEE RESPONSIBILITIES AND CONDUCT General § 99.735-1 Cross-reference to ethical conduct... the executive branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Department of...

39 CFR 3000.735-101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Cross-reference to employee ethical conduct... employee ethical conduct standards and financial disclosure regulations. Employees of the Postal Regulatory Commission (Commission) are subject and should refer to the executive branch-wide Standards of Ethical...

29 CFR 2703.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Cross-reference to employee ethical conduct standards and...-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees... of Ethical Conduct at 5 CFR part 2635; the Commission's regulations at 5 CFR part 8401, which...

29 CFR 2703.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 9 2013-07-01 2013-07-01 false Cross-reference to employee ethical conduct standards and...-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees... of Ethical Conduct at 5 CFR part 2635; the Commission's regulations at 5 CFR part 8401, which...

49 CFR 99.735-1 - Cross-reference to ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 1 2013-10-01 2013-10-01 false Cross-reference to ethical conduct standards and... Transportation EMPLOYEE RESPONSIBILITIES AND CONDUCT General § 99.735-1 Cross-reference to ethical conduct... the executive branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Department of...

16 CFR § 1030.101 - Cross-references to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Cross-references to employee ethical conduct...-references to employee ethical conduct standards and financial disclosure regulations. Employees of the Consumer Product Safety Commission are subject to the Standards of Ethical Conduct, 5 CFR part 2635, which...

45 CFR 706.1 - Cross-references to employee ethical conduct standards, financial disclosure and financial...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 3 2012-10-01 2012-10-01 false Cross-references to employee ethical conduct... EMPLOYEE RESPONSIBILITIES AND CONDUCT § 706.1 Cross-references to employee ethical conduct standards... States Commission on Civil Rights are subject to the executive branch standards of ethical conduct...

49 CFR 99.735-1 - Cross-reference to ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 1 2014-10-01 2014-10-01 false Cross-reference to ethical conduct standards and... Transportation EMPLOYEE RESPONSIBILITIES AND CONDUCT General § 99.735-1 Cross-reference to ethical conduct... the executive branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Department of...

45 CFR 1105.1 - Cross-reference to employee ethical conduct standards and financial disclosure and financial...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 3 2012-10-01 2012-10-01 false Cross-reference to employee ethical conduct... STANDARDS OF CONDUCT FOR EMPLOYEES § 1105.1 Cross-reference to employee ethical conduct standards and... ethical conduct at 5 CFR part 2635; the executive branch employees responsibilities and conduct...

29 CFR 2703.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 9 2014-07-01 2014-07-01 false Cross-reference to employee ethical conduct standards and...-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees... of Ethical Conduct at 5 CFR part 2635; the Commission's regulations at 5 CFR part 8401, which...

39 CFR 3000.735-101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 39 Postal Service 1 2013-07-01 2013-07-01 false Cross-reference to employee ethical conduct... employee ethical conduct standards and financial disclosure regulations. Employees of the Postal Regulatory Commission (Commission) are subject and should refer to the executive branch-wide Standards of Ethical...

39 CFR 3000.735-101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 39 Postal Service 1 2012-07-01 2012-07-01 false Cross-reference to employee ethical conduct... employee ethical conduct standards and financial disclosure regulations. Employees of the Postal Regulatory Commission (Commission) are subject and should refer to the executive branch-wide Standards of Ethical...

45 CFR 1105.1 - Cross-reference to employee ethical conduct standards and financial disclosure and financial...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Cross-reference to employee ethical conduct... STANDARDS OF CONDUCT FOR EMPLOYEES § 1105.1 Cross-reference to employee ethical conduct standards and... ethical conduct at 5 CFR part 2635; the executive branch employees responsibilities and conduct...

29 CFR 2703.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 9 2012-07-01 2012-07-01 false Cross-reference to employee ethical conduct standards and...-reference to employee ethical conduct standards and financial disclosure regulations. Members and employees... of Ethical Conduct at 5 CFR part 2635; the Commission's regulations at 5 CFR part 8401, which...

45 CFR 1105.1 - Cross-reference to employee ethical conduct standards and financial disclosure and financial...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Cross-reference to employee ethical conduct... STANDARDS OF CONDUCT FOR EMPLOYEES § 1105.1 Cross-reference to employee ethical conduct standards and... ethical conduct at 5 CFR part 2635; the executive branch employees responsibilities and conduct...

39 CFR 3000.735-101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 39 Postal Service 1 2014-07-01 2014-07-01 false Cross-reference to employee ethical conduct... employee ethical conduct standards and financial disclosure regulations. Employees of the Postal Regulatory Commission (Commission) are subject and should refer to the executive branch-wide Standards of Ethical...

45 CFR 706.1 - Cross-references to employee ethical conduct standards, financial disclosure and financial...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Cross-references to employee ethical conduct... EMPLOYEE RESPONSIBILITIES AND CONDUCT § 706.1 Cross-references to employee ethical conduct standards... States Commission on Civil Rights are subject to the executive branch standards of ethical conduct...

45 CFR 706.1 - Cross-references to employee ethical conduct standards, financial disclosure and financial...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Cross-references to employee ethical conduct... EMPLOYEE RESPONSIBILITIES AND CONDUCT § 706.1 Cross-references to employee ethical conduct standards... States Commission on Civil Rights are subject to the executive branch standards of ethical conduct...

49 CFR 99.735-1 - Cross-reference to ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 1 2012-10-01 2012-10-01 false Cross-reference to ethical conduct standards and... Transportation EMPLOYEE RESPONSIBILITIES AND CONDUCT General § 99.735-1 Cross-reference to ethical conduct... the executive branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Department of...

SHORT COMMUNICATION: Transportable Zener-diode Voltage Standard

NASA Astrophysics Data System (ADS)

Karpov, O. V.; Shulga, V. M.; Shakirzyanova, F. R.; Sarandi, A. E.

1994-01-01

Five transportable Zener-diode dc voltage standards have been developed, fabricated and investigated at the NPO VNIIFTRI. The standards were designed to transfer the unit of electromotive force (emf) from Josephson reference standards to measuring instruments. Following the results of these investigations, standard N 02 has been used for intercomparison of the Russian Josephson reference standards.

Final Report: Comparison of the primary (national) standards of low-pressure gas flow

NASA Astrophysics Data System (ADS)

Benková, Miroslava; Makovnik, Stefan; Mickan, Bodo

2015-01-01

The EURAMET.M.FF-K6 comparison was organized for the purpose of determination of the degree of equivalence of the primary (national) standards for low-pressure gas flow measurement over the range (2 to 100) m3/h and was performed simultaneously with CCM.FF-K6.2011 with the same transfer standard. A rotary gas meter G65 was used as a transfer standard. The measurements were provided by prescribed reference conditions. Fifteen laboratories from EURAMET participated in this key comparison - SMU, Slovakia; PTB, Germany; CEM, Spain; LNE-LADG, France; VSL, Netherlands; CMI, Czech Republic; BEV, Austria; MKEH, Hungary; GUM Poland; SP, Sweden; METAS, Switzerland; DMDM, Serbia; TUBITAK-UME, Turkey; EIM, Greece; IMBiH, Bosnia-Herzegovina. The EURAMET.M.FF-K6 is linked to the CCM.FF-K6.2011 by correcting the results of three linking laboratories (Slovakia SMU, Germany PTB and France LNE LADG). This correction provides an estimate of what would have been the result from the EURAMET.M-FF-K6 participants, if they had actually participated in CCM.FF-K6.2011. According to the evaluation 93.7 % of the results were consistent with KCRV, 3.4 % of the results were in the warning level and 2.9 % of the results were inconsistent. The results of this comparison can be used for review of the CMC tables. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Oxygen Candle Background for Subs and Space

NASA Technical Reports Server (NTRS)

Graf, John

2017-01-01

"At any time and without warning, a submarine may have to remain submerged for several days on account of the presence of the enemy, or rough weather, or serious accident to the machinery. Fortunately such occurrences are rare; but every commanding officer must be prepared to meet such an emergency that will afford his men the greatest possible chance of survival." Reference (1) This quotation is taken from a review of submarine air purification technology published by the Bureau of Medicine and Surgery in 1919. At that time, the U.S. Navy had just begun to experiment with possible air purification devices and supplies of oxygen that might permit submarines to remain submerged longer that the untreated closed atmosphere would allow. Submariners were exposed to elevated levels of carbon dioxide and reduced levels of oxygen that would be considered completely unacceptable by current standards. It was a different world, but humans are still humans, and the requirements for safe and effective functioning in a self-contained environment are really unchanged. The maximum submergence time for submarines as published in that work was approximately 48 hours, reference (1) In early submarines, the preferred supply of oxygen was 1800 psig compressed gas bled into the boat as needed, references (1,2). The need for added oxygen was occasionally "measured" by the physiological impact on the crew rather than a reliable instrument, reference (1). The design of submarine oxygen supply was limited to approximately 25 day submerged operation, reference (2). It was not until 1958 that U.S. submarines were able to carry out dives beyond that period and necessitated new sources of oxygen, reference (2). A curious second source of oxygen at the time was compressed air vessels that were bled into the boat while "vitiated" air (air with reduced oxygen and elevated carbon dioxide) from the opposite end of the boat was compressed into waiting empty vessels, reference (1). The periodic use of pressurized air to control oxygen caused swings in ambient pressure that was uncomfortable to the crew, reference (1). As early as 1919, liquid oxygen was a commercially available product and its use on submarines was contemplated, reference (1). It is interesting that even at this date, 1919, the danger of oils or greases when exposed to compressed or liquid oxygen was recognized: "One precaution must be always taken. No oil or grease should be used in the gauge or fittings or a dangerous explosion may result."

77 FR 205 - Federal Acquisition Regulation; Federal Acquisition Circular 2005-55; Small Entity Compliance Guide

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-03

... System. VI Updated Financial 2010-005 Chambers. Accounting Standards Board Accounting References. VII... Financial Accounting Standards Board Accounting References (FAR Case 2010-005) This final rule amends the... authoritative accounting standards owing to the Financial Accounting Standards Board's Accounting Standards...

Bilateral comparison of 10 V standards between the NSAI-NML (Ireland) and the BIPM, March to April 2011 (part of the ongoing BIPM key comparison BIPM.EM-K11.b)

NASA Astrophysics Data System (ADS)

Power, O.; Solve, S.; Chayramy, R.; Stock, M.

2011-01-01

As a part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out from March to April 2011. Two BIPM Zener diode-based travelling standards (Fluke 732B) were transported by freight to NSAI-NML. At NSAI-NML, the 10 V output EMF of each travelling standard was measured by direct comparison with a group of characterized Zener diode-based electronic voltage standards. At the BIPM, the travelling standards were calibrated before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages on internal temperature and ambient pressure. The comparison results show that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated expanded uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Challenges in standardization of blood pressure measurement at the population level.

PubMed

Tolonen, Hanna; Koponen, Päivikki; Naska, Androniki; Männistö, Satu; Broda, Grazyna; Palosaari, Tarja; Kuulasmaa, Kari

2015-04-10

Accurate blood pressure measurements are needed in clinical practice, intervention studies and health examination surveys. Blood pressure measurements are sensitive: their accuracy can be affected by measurement environment, behaviour of the subject, measurement procedures, devices used for the measurement and the observer. To minimize errors in blood pressure measurement, a standardized measurement protocol is needed. The European Health Examination Survey (EHES) Pilot project was conducted in 2009-2012. A pilot health examination survey was conducted in 12 countries using a standardized protocol. The measurement protocols used in each survey, training provided for the measurers, measurement data, and observations during site visits were collected and evaluated to assess the level of standardization. The EHES measurement protocol for blood pressure was followed accurately in all 12 pilot surveys. Most of the surveys succeeded in organizing a quiet and comfortable measurement environment, and staff instructed survey participants appropriately before examination visits. In all surveys, blood pressure was measured three times, from the right arm in a sitting posture. The biggest variation was in the device used for the blood pressure measurement. It is possible to reach a high level of standardization for blood pressure measurements across countries and over time. A detailed, standardized measurement protocol, and adequate training and monitoring during the fieldwork and centrally organized quality assessment of the data are needed. The recent EU regulation banning the sale of mercury sphygmomanometer in European Union Member States has set new challenges for the standardization of measurement devices since the validity of oscillometric measurements is device-specific and performance of aneroid devices depends very much on calibration.

Ambulatory Blood Pressure Monitoring (ABPM) as the reference standard for diagnosis of hypertension and assessment of vascular risk in adults.

PubMed

Hermida, Ramón C; Smolensky, Michael H; Ayala, Diana E; Portaluppi, Francesco

2015-01-01

New information has become available since the ISC, AAMCC, and SECAC released their first extensive guidedelines to improve the diagnosis and treatment of adult arterial hypertension. A critical assessment of evidence and a comparison of what international guidelines now propose are the basis for the following statements, which update the recommendations first issued in 2013. Office blood pressure (BP) measurements should no longer be considered to be the "gold standard" for the diagnosis of hypertension and assessment of cardiovascular risk. Relying on office BP, even when supplemented with at-home wake-time self-measurements, to identify high-risk individuals, disregarding circadian BP patterning and asleep BP level, leads to potential misclassification of 50% of all evaluated persons. Accordingly, ambulatory BP monitoring is the recommended reference standard for the diagnosis of true hypertension and accurate assessment of cardiovascular risk in all adults ≥18 yrs of age, regardless of whether office BP is normal or elevated. Asleep systolic BP mean is the most significant independent predictor of cardiovascular events. The sleep-time relative SBP decline adds prognostic value to the statistical model that already includes the asleep systolic BP mean and corrected for relevant confounding variables. Accordingly, the asleep systolic BP mean is the recommended protocol to diagnose hypertension, assess cardiovascular risk, and predict cardiovascular event-free interval. In men, and in the absence of compelling clinical conditions, reference thresholds for diagnosing hypertension are 120/70 mmHg for the asleep systolic/diastolic BP means derived from ambulatory BP monitoring. However, in women, in the absence of complicating co-morbidities, the same thresholds are lower by 10/5 mmHg, i.e., 110/65 mmHg for the asleep means. In high-risk patients, including those diagnosed with diabetes or chronic kidney disease, and/or those having experienced past cardiovascular events, the thresholds are even lower by 15/10 mmHg, i.e., 105/60 mmHg. Bedtime treatment with the full daily dose of ≥1 hypertension medications is recommended as a cost-effective means to improve the management of hypertension and reduce hypertension-associated risk. Bedtime treatment entailing the full daily dose of ≥1 conventional hypertension medications must be the therapeutic regimen of choice for the elderly and those with diabetes, resistant and secondary hypertension, chronic kidney disease, obstructive sleep apnea, and medical history of past cardiovascular events, among others, given their documented high prevalence of sleep-time hypertension.

Reference and Standard Atmosphere Models

NASA Technical Reports Server (NTRS)

Johnson, Dale L.; Roberts, Barry C.; Vaughan, William W.; Parker, Nelson C. (Technical Monitor)

2002-01-01

This paper describes the development of standard and reference atmosphere models along with the history of their origin and use since the mid 19th century. The first "Standard Atmospheres" were established by international agreement in the 1920's. Later some countries, notably the United States, also developed and published "Standard Atmospheres". The term "Reference Atmospheres" is used to identify atmosphere models for specific geographical locations. Range Reference Atmosphere Models developed first during the 1960's are examples of these descriptions of the atmosphere. This paper discusses the various models, scopes, applications and limitations relative to use in aerospace industry activities.

Renal artery stenosis in children: therapeutic percutaneous balloon and stent angioplasty.

PubMed

Colyer, Jessica H; Ratnayaka, Kanishka; Slack, Michael C; Kanter, Joshua P

2014-06-01

Renal artery stenosis (RAS) accounts for 10 % of cases of systemic hypertension in children. Initial management involves anti-hypertensive therapy. Percutaneous interventions are documented for the treatment of RAS in the adult population. In children, case reports suggest benefit. This is a retrospective analysis of consecutive patients referred for catheterization for RAS between 2002 and 2010 at a single institution. Recorded variables included: age, weight, systemic blood pressure, minimal luminal diameter, interventional devices, antihypertensive medications, contrast volume, and complications. Twelve patients (median age 8.2, IQR 6-12.4 years); median weight 42.8 kg, IQR: 25-47.4 kg) were referred for renal artery catheterization and underwent percutaneous intervention. Overall, minimal luminal diameter (MLD) increased by 1.2 ± 0.9 mm for all patients (p < 0.05) and by 1.3 ± 0.9 mm for post-renal transplant patients (p < 0.05). Only stent angioplasty patients demonstrated significant improved blood pressure (p < 0.05). One patient had stent thrombosis requiring re-intervention with repeat balloon angioplasty. This retrospective analysis suggests that percutaneous intervention might play a role in the management of RAS, with an improvement in MLD in children with RAS. Transcatheter intervention is technically feasible with low morbidity. A prospective, longitudinal study is warranted to compare standard medical therapy with percutaneous interventions.

Normative behavioral thresholds for short tone-bursts.

PubMed

Beattie, R C; Rochverger, I

2001-10-01

Although tone-bursts have been commonly used in auditory brainstem response (ABR) evaluations for many years, national standards describing normal calibration values have not been established. This study was designed to gather normative threshold data to establish a physical reference for tone-burst stimuli that can be reproduced across clinics and laboratories. More specifically, we obtained norms for 3-msec tone-bursts presented at two repetition rates (9.3/sec and 39/sec), two gating functions (Trapezoid and Blackman), and four frequencies (500, 1000, 2000, and 4000 Hz). Our results are specified using three physical references: dB peak sound pressure level, dB peak-to-peak equivalent sound pressure level, and dB SPL (fast meter response, rate = 50 stimuli/sec). These data are offered for consideration when calibrating ABR equipment. The 39/sec stimulus rate yielded tone-burst thresholds that were approximately 3 dB lower than the 9.3/sec rate. The improvement in threshold with increasing stimulus rate may reflect the ability of the auditory system to integrate energy that occurs within a time interval of 200 to 500 msec (temporal integration). The Trapezoid gating function yielded thresholds that averaged 1.4 dB lower than the Blackman function. Although these differences are small and of little clinical importance, the cumulative effects of several instrument and/or procedural variables may yield clinically important differences.

77 FR 21734 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Romania...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-11

... Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Romania: Extension of Time Limit for... diameter carbon and alloy seamless standard, line and pressure pipe from Romania for the period August 1... investigation based upon the allegation of the petitioner, U.S. Steel. See the memorandum to Susan Kuhbach dated...

Determination of polycyclic aromatic hydrocarbons in fractions in asphalt mixtures using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization.

PubMed

Nascimento, Paulo Cicero; Gobo, Luciana Assis; Bohrer, Denise; Carvalho, Leandro Machado; Cravo, Margareth Coutinho; Leite, Leni Figueiredo Mathias

2015-07-01

An analytical method using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization for the determination of polycyclic aromatic hydrocarbons in asphalt fractions has been developed. The 14 compounds determined, characterized by having two or more condensed aromatic rings, are expected to be present in asphalt and are considered carcinogenic and mutagenic. The parameters of the atmospheric pressure chemical ionization interface were optimized to obtain the highest possible sensitivity for all of the compounds. The limits of detection ranged from 0.5 to 346.5 μg/L and the limits of quantification ranged from 1.7 to 1550 μg/L. The method was validated against a diesel particulate extract standard reference material (NIST SRM 1975), and the obtained concentrations agreed with the certified values. The method was applied to asphalt samples after its fractionation according to ASTM D4124 and the method of Green. The concentrations of the seven polycyclic aromatic hydrocarbons quantified in the sample ranged from 0.86 mg/kg for benzo[ghi]perylene to 98.32 mg/kg for fluorene. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Qualitative and quantitative assessment of unresolved complex mixture in PM2.5 of Bakersfield, CA

NASA Astrophysics Data System (ADS)

Nallathamby, Punith Dev; Lewandowski, Michael; Jaoui, Mohammed; Offenberg, John H.; Kleindienst, Tadeusz E.; Rubitschun, Caitlin; Surratt, Jason D.; Usenko, Sascha; Sheesley, Rebecca J.

2014-12-01

The 2010 CalNex (California Nexus) field experiment offered an opportunity for detailed characterization of atmospheric particulate carbon composition and sources in Bakersfield, CA. In the current study, the authors describe and employ a new protocol for reporting unresolved complex mixture (UCM) in over 30 daily samples. The Bakersfield, CA site has significant contribution from UCM, 2.9 ± 2.2% of the daily OC, which makes it an ideal first application. The new protocol reports two UCM peaks for Bakersfield with unique mean vapor pressure, retention time, mass spectra and daily ambient concentration trends. The first UCM peak, UCM-A, was comprised of semi-volatile compounds including alkanes, alkenes, and alkynes, with a mean vapor pressure of 2E-04 Torr and medium to heavy-duty diesel exhaust as a likely source. The second UCM peak, UCM-B, was comprised of linear, branched, and cyclic alkanes, with a mean vapor pressure of 1E-08 Torr. UCM-B had strong similarities to UCM in the NIST Standard Reference Material 1649b (urban dust) and to previously reported, detailed UCM for a representative Bakersfield sample, with possible sources including: motor vehicle exhaust, agricultural activities, and construction activities.

Measurement Uncertainty of Dew-Point Temperature in a Two-Pressure Humidity Generator

NASA Astrophysics Data System (ADS)

Martins, L. Lages; Ribeiro, A. Silva; Alves e Sousa, J.; Forbes, Alistair B.

2012-09-01

This article describes the measurement uncertainty evaluation of the dew-point temperature when using a two-pressure humidity generator as a reference standard. The estimation of the dew-point temperature involves the solution of a non-linear equation for which iterative solution techniques, such as the Newton-Raphson method, are required. Previous studies have already been carried out using the GUM method and the Monte Carlo method but have not discussed the impact of the approximate numerical method used to provide the temperature estimation. One of the aims of this article is to take this approximation into account. Following the guidelines presented in the GUM Supplement 1, two alternative approaches can be developed: the forward measurement uncertainty propagation by the Monte Carlo method when using the Newton-Raphson numerical procedure; and the inverse measurement uncertainty propagation by Bayesian inference, based on prior available information regarding the usual dispersion of values obtained by the calibration process. The measurement uncertainties obtained using these two methods can be compared with previous results. Other relevant issues concerning this research are the broad application to measurements that require hygrometric conditions obtained from two-pressure humidity generators and, also, the ability to provide a solution that can be applied to similar iterative models. The research also studied the factors influencing both the use of the Monte Carlo method (such as the seed value and the convergence parameter) and the inverse uncertainty propagation using Bayesian inference (such as the pre-assigned tolerance, prior estimate, and standard deviation) in terms of their accuracy and adequacy.

46 CFR 54.10-10 - Standard hydrostatic test (modifies UG-99).

Code of Federal Regulations, 2014 CFR

2014-10-01

... PRESSURE VESSELS Inspection, Reports, and Stamping § 54.10-10 Standard hydrostatic test (modifies UG-99). (a) All pressure vessels shall satisfactorily pass the hydrostatic test prescribed by this section, except those pressure vessels noted under § 54.10-15(a). (b) The hydrostatic-test pressure must be at...

15 CFR 200.104 - Standard reference materials.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the NIST National Measurement Laboratory administers a program to provide many types of well... be readily referred to a common base. NIST SP 260 is a catalog of Standard Reference Materials available from NIST. ...

15 CFR 200.104 - Standard reference materials.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the NIST National Measurement Laboratory administers a program to provide many types of well... be readily referred to a common base. NIST SP 260 is a catalog of Standard Reference Materials available from NIST. ...

15 CFR 200.104 - Standard reference materials.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the NIST National Measurement Laboratory administers a program to provide many types of well... be readily referred to a common base. NIST SP 260 is a catalog of Standard Reference Materials available from NIST. ...

15 CFR 200.104 - Standard reference materials.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the NIST National Measurement Laboratory administers a program to provide many types of well... be readily referred to a common base. NIST SP 260 is a catalog of Standard Reference Materials available from NIST. ...

15 CFR 200.104 - Standard reference materials.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the NIST National Measurement Laboratory administers a program to provide many types of well... be readily referred to a common base. NIST SP 260 is a catalog of Standard Reference Materials available from NIST. ...

Location of the internal carotid artery and ophthalmic artery segments for non-invasive intracranial pressure measurement by multi-depth TCD.

PubMed

Hamarat, Yasin; Deimantavicius, Mantas; Kalvaitis, Evaldas; Siaudvytyte, Lina; Januleviciene, Ingrida; Zakelis, Rolandas; Bartusis, Laimonas

2017-12-01

The aim of the present study was to locate the ophthalmic artery by using the edge of the internal carotid artery (ICA) as the reference depth to perform a reliable non-invasive intracranial pressure measurement via a multi-depth transcranial Doppler device and to then determine the positions and angles of an ultrasonic transducer (UT) on the closed eyelid in the case of located segments. High tension glaucoma (HTG) patients and healthy volunteers (HVs) undergoing non-invasive intracranial pressure measurement were selected for this prospective study. The depth of the edge of the ICA was identified, followed by a selection of the depths of the IOA and EOA segments. The positions and angles of the UT on the closed eyelid were measured. The mean depth of the identified ICA edge for HTG patients was 64.3 mm and was 63.0 mm for HVs (p = 0.21). The mean depth of the selected IOA segment for HTG patients was 59.2 mm and 59.3 mm for HVs (p = 0.91). The mean depth of the selected EOA segment for HTG patients was 48.5 mm and 49.8 mm for HVs (p = 0.14). The difference in the located depths of the segments between groups was not statistically significant. The results showed a significant difference in the measured UT angles in the case of the identified edge of the ICA and selected ophthalmic artery segments (p = 0.0002). We demonstrated that locating the IOA and EOA segments can be achieved using the edge of the ICA as a reference point. OA: ophthalmic artery; IOA: intracranial segments of the ophthalmic artery; EOA: extracranial segments of the ophthalmic artery; ICA: internal carotid artery; UT: ultrasonic transducer; HTG: high tension glaucoma; SD: standard deviation; ICP: intracranial pressure; TCD: transcranial Doppler.

Coherent Frequency Reference System for the NASA Deep Space Network

NASA Technical Reports Server (NTRS)

Tucker, Blake C.; Lauf, John E.; Hamell, Robert L.; Gonzaler, Jorge, Jr.; Diener, William A.; Tjoelker, Robert L.

2010-01-01

The NASA Deep Space Network (DSN) requires state-of-the-art frequency references that are derived and distributed from very stable atomic frequency standards. A new Frequency Reference System (FRS) and Frequency Reference Distribution System (FRD) have been developed, which together replace the previous Coherent Reference Generator System (CRG). The FRS and FRD each provide new capabilities that significantly improve operability and reliability. The FRS allows for selection and switching between frequency standards, a flywheel capability (to avoid interruptions when switching frequency standards), and a frequency synthesis system (to generate standardized 5-, 10-, and 100-MHz reference signals). The FRS is powered by redundant, specially filtered, and sustainable power systems and includes a monitor and control capability for station operations to interact and control the frequency-standard selection process. The FRD receives the standardized 5-, 10-, and 100-MHz reference signals and distributes signals to distribution amplifiers in a fan out fashion to dozens of DSN users that require the highly stable reference signals. The FRD is also powered by redundant, specially filtered, and sustainable power systems. The new DSN Frequency Distribution System, which consists of the FRS and FRD systems described here, is central to all operational activities of the NASA DSN. The frequency generation and distribution system provides ultra-stable, coherent, and very low phase-noise references at 5, l0, and 100 MHz to between 60 and 100 separate users at each Deep Space Communications Complex.

PPM mixtures of formaldehyde in gas cylinders: Stability and analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wong, K.C.; Miller, S.B.; Patterson, L.M.

1999-07-01

Scott Specialty Gases has been successful in producing stable calibration gases of formaldehyde at low concentration. Critical to this success has been the development of a treatment process for high pressure aluminum cylinders. Formaldehyde cylinders having concentrations of 20ppm and 4ppm were found to show only small decline in concentrations over a period of approximately 12 months. Since no NIST traceable formaldehyde standards (or Standard Reference Material) are available, all Scott's formaldehyde cylinders were originally certified by traditional impinger method. This method involves an extremely tedious purification procedure for 2,4-dinitrophenylhydrazine (2,4-DNPH). A modified version of the impinger method has beenmore » developed and does not require extensive reagent purification for formaldehyde analysis. Extremely low formaldehyde blanks have been obtained with the modified method. The HPLC conditions in the original method were used for chromatographic separations. The modified method results in a lower analytical uncertainty for the formaldehyde standard mixtures. Consequently, it is possible to discern small differences between analytical results that are important for stability study.« less

Tree ring wood analysis after hydrogen peroxide pressure decomposition with inductively coupled plasma atomic emission spectrometry and electrothermal vaporization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matusiewicz, H.; Barnes, R.M.

1985-02-01

A method utilizing pressure decomposition to minimize sample pretreatment is described for the inductively coupled plasma atomic emission spectrometric analysis of red spruce and sugar maple. Cores collected from trees growing on Camels Hump Mountain, Vermont, were divided into decade increments in order to monitor the temporal changes in concentrations of 21 elements. Dried wood samples were decomposed in a bomb made of Teflon with 50% hydrogen peroxide heated in an oven at 125/sup 0/C for 4 h. The digestion permitted use of aqueous standards and minimized any potential matrix effects. The element concentrations were obtained sequentially by electrothermal vaporizationmore » ICP-AES using 5 ..mu..L sample aliquots. The method precision varied between 3 and 12%. Elements forming oxyanions (Al, As, Fe, Ge, Mn, Si, V) were found at elevated concentrations during the most recent three decades, while other metal (e.g., Mg, Zn) concentrations were unchanged or decreased. 45 references, 6 tables, 1 figure.« less

Pressure balance cross-calibration method using a pressure transducer as transfer standard

PubMed Central

Olson, D; Driver, R. G.; Yang, Y

2016-01-01

Piston gauges or pressure balances are widely used to realize the SI unit of pressure, the pascal, and to calibrate pressure sensing devices. However, their calibration is time consuming and requires a lot of technical expertise. In this paper, we propose an alternate method of performing a piston gauge cross calibration that incorporates a pressure transducer as an immediate in-situ transfer standard. For a sufficiently linear transducer, the requirement to exactly balance the weights on the two pressure gauges under consideration is greatly relaxed. Our results indicate that this method can be employed without a significant increase in measurement uncertainty. Indeed, in the test case explored here, our results agreed with the traditional method within standard uncertainty, which was less than 6 parts per million. PMID:28303167

12 CFR 336.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Cross-reference to employee ethical conduct... and Conduct § 336.1 Cross-reference to employee ethical conduct standards and financial disclosure... Branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Corporation regulation at 5 CFR part...

12 CFR 264.101 - Cross-reference to employees' ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 3 2011-01-01 2011-01-01 false Cross-reference to employees' ethical conduct... § 264.101 Cross-reference to employees' ethical conduct standards and financial disclosure regulations... branch-wide standards of ethical conduct at 5 CFR part 2635 and the Board's regulation at 5 CFR part 6801...

10 CFR 1010.102 - Cross-references to employee ethical conduct standards, financial disclosure regulations, and...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Cross-references to employee ethical conduct standards... ENERGY (GENERAL PROVISIONS) CONDUCT OF EMPLOYEES § 1010.102 Cross-references to employee ethical conduct... Standards of Ethical Conduct for Employees of the Executive Branch at 5 CFR part 2635, the DOE regulation at...

12 CFR 336.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Cross-reference to employee ethical conduct... and Conduct § 336.1 Cross-reference to employee ethical conduct standards and financial disclosure... Branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Corporation regulation at 5 CFR part...

12 CFR 264.101 - Cross-reference to employees' ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Cross-reference to employees' ethical conduct... § 264.101 Cross-reference to employees' ethical conduct standards and financial disclosure regulations... branch-wide standards of ethical conduct at 5 CFR part 2635 and the Board's regulation at 5 CFR part 6801...

12 CFR 264.101 - Cross-reference to employees' ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 4 2012-01-01 2012-01-01 false Cross-reference to employees' ethical conduct... AND CONDUCT § 264.101 Cross-reference to employees' ethical conduct standards and financial disclosure... executive branch-wide standards of ethical conduct at 5 CFR part 2635 and the Board's regulation at 5 CFR...

12 CFR 264.101 - Cross-reference to employees' ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Cross-reference to employees' ethical conduct... AND CONDUCT § 264.101 Cross-reference to employees' ethical conduct standards and financial disclosure... executive branch-wide standards of ethical conduct at 5 CFR part 2635 and the Board's regulation at 5 CFR...

12 CFR 336.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Cross-reference to employee ethical conduct... and Conduct § 336.1 Cross-reference to employee ethical conduct standards and financial disclosure... Branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Corporation regulation at 5 CFR part...

12 CFR 336.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Cross-reference to employee ethical conduct... and Conduct § 336.1 Cross-reference to employee ethical conduct standards and financial disclosure... Branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Corporation regulation at 5 CFR part...

12 CFR 336.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Cross-reference to employee ethical conduct... and Conduct § 336.1 Cross-reference to employee ethical conduct standards and financial disclosure... Branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Corporation regulation at 5 CFR part...

12 CFR 264.101 - Cross-reference to employees' ethical conduct standards and financial disclosure regulations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 4 2013-01-01 2013-01-01 false Cross-reference to employees' ethical conduct... AND CONDUCT § 264.101 Cross-reference to employees' ethical conduct standards and financial disclosure... executive branch-wide standards of ethical conduct at 5 CFR part 2635 and the Board's regulation at 5 CFR...

Intercomparison of Lab-Based Soil Water Extraction Methods for Stable Water Isotope Analysis

NASA Astrophysics Data System (ADS)

Pratt, D.; Orlowski, N.; McDonnell, J.

2016-12-01

The effect of pore water extraction technique on resultant isotopic signature is poorly understood. Here we present results of an intercomparison of five common lab-based soil water extraction techniques: high pressure mechanical squeezing, centrifugation, direct vapor equilibration, microwave extraction, and cryogenic extraction. We applied five extraction methods to two physicochemically different standard soil types (silty sand and clayey loam) that were oven-dried and rewetted with water of known isotopic composition at three different gravimetric water contents (8, 20, and 30%). We tested the null hypothisis that all extraction techniques would provide the same isotopic result independent from soil type and water content. Our results showed that the extraction technique had a significant effect on the soil water isotopic composition. Each method exhibited deviations from spiked reference water, with soil type and water content showing a secondary effect. Cryogenic extraction showed the largest deviations from the reference water, whereas mechanical squeezing and centrifugation provided the closest match to the reference water for both soil types. We also compared results for each extraction technique that produced liquid water on both an OA-ICOS and IRMS; differences between them were negligible.

An integrated low phase noise radiation-pressure-driven optomechanical oscillator chipset

PubMed Central

Luan, Xingsheng; Huang, Yongjun; Li, Ying; McMillan, James F.; Zheng, Jiangjun; Huang, Shu-Wei; Hsieh, Pin-Chun; Gu, Tingyi; Wang, Di; Hati, Archita; Howe, David A.; Wen, Guangjun; Yu, Mingbin; Lo, Guoqiang; Kwong, Dim-Lee; Wong, Chee Wei

2014-01-01

High-quality frequency references are the cornerstones in position, navigation and timing applications of both scientific and commercial domains. Optomechanical oscillators, with direct coupling to continuous-wave light and non-material-limited f × Q product, are long regarded as a potential platform for frequency reference in radio-frequency-photonic architectures. However, one major challenge is the compatibility with standard CMOS fabrication processes while maintaining optomechanical high quality performance. Here we demonstrate the monolithic integration of photonic crystal optomechanical oscillators and on-chip high speed Ge detectors based on the silicon CMOS platform. With the generation of both high harmonics (up to 59th order) and subharmonics (down to 1/4), our chipset provides multiple frequency tones for applications in both frequency multipliers and dividers. The phase noise is measured down to −125 dBc/Hz at 10 kHz offset at ~400 μW dropped-in powers, one of the lowest noise optomechanical oscillators to date and in room-temperature and atmospheric non-vacuum operating conditions. These characteristics enable optomechanical oscillators as a frequency reference platform for radio-frequency-photonic information processing. PMID:25354711

Setting nutrient thresholds to support an ecological assessment based on nutrient enrichment, potential primary production and undesirable disturbance.

PubMed

Devlin, Michelle; Painting, Suzanne; Best, Mike

2007-01-01

The EU Water Framework Directive recognises that ecological status is supported by the prevailing physico-chemical conditions in each water body. This paper describes an approach to providing guidance on setting thresholds for nutrients taking account of the biological response to nutrient enrichment evident in different types of water. Indices of pressure, state and impact are used to achieve a robust nutrient (nitrogen) threshold by considering each individual index relative to a defined standard, scale or threshold. These indices include winter nitrogen concentrations relative to a predetermined reference value; the potential of the waterbody to support phytoplankton growth (estimated as primary production); and detection of an undesirable disturbance (measured as dissolved oxygen). Proposed reference values are based on a combination of historical records, offshore (limited human influence) nutrient concentrations, literature values and modelled data. Statistical confidence is based on a number of attributes, including distance of confidence limits away from a reference threshold and how well the model is populated with real data. This evidence based approach ensures that nutrient thresholds are based on knowledge of real and measurable biological responses in transitional and coastal waters.

Comparison of a portable micro-X-ray fluorescence spectrometry with inductively coupled plasma atomic emission spectrometry for the ancient ceramics analysis

NASA Astrophysics Data System (ADS)

Papadopoulou, D. N.; Zachariadis, G. A.; Anthemidis, A. N.; Tsirliganis, N. C.; Stratis, J. A.

2004-12-01

Two multielement instrumental methods of analysis, micro X-ray fluorescence spectrometry (micro-XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were applied for the analysis of 7th and 5th century B.C. ancient ceramic sherds in order to evaluate the above two methods and to assess the potential to use the current compact and portable micro-XRF instrument for the in situ analysis of ancient ceramics. The distinguishing factor of interest is that micro-XRF spectrometry offers the possibility of a nondestructive analysis, an aspect of primary importance in the compositional analysis of cultural objects. Micro-XRF measurements were performed firstly directly on the ceramic sherds with no special pretreatment apart from surface cleaning (micro-XRF on sherds) and secondly on pressed pellet disks which were prepared for each ceramic sherd (micro-XRF on pellet). For the ICP-AES determination of elements, test solutions were prepared by the application of a microwave-assisted decomposition procedure in closed high-pressure PFA vessels. Also, the standard reference material SARM 69 was used for the efficiency calibration of the micro-XRF instrument and was analysed by both methods. In order to verify the calibration, the standard reference materials NCS DC 73332 and SRM620 as well as the reference materials AWI-1 and PRI-1 were analysed by micro-XRF. Elemental concentrations determined by the three analytical procedures (ICP-AES, micro-XRF on sherds and micro-XRF on pellets) were statistically treated by correlation analysis and Student's t-test (at the 95% confidence level).

Surface properties of thermally treated composite wood panels

NASA Astrophysics Data System (ADS)

Croitoru, Catalin; Spirchez, Cosmin; Lunguleasa, Aurel; Cristea, Daniel; Roata, Ionut Claudiu; Pop, Mihai Alin; Bedo, Tibor; Stanciu, Elena Manuela; Pascu, Alexandru

2018-04-01

Composite finger-jointed spruce and oak wood panels have been thermally treated under standard pressure and oxygen content conditions at two different temperatures, 180 °C and respectively 200 °C for short time periods (3 and 5 h). Due to the thermally-aided chemical restructuration of the wood components, a decrease in water uptake and volumetric swelling values with up to 45% for spruce and 35% for oak have been registered, comparing to the reference samples. In relation to water resistance, a 15% increase of the dispersive component of the surface energy has been registered for the thermal-treated spruce panels, which impedes water spreading on the surface. The thermal-treated wood presents superior resistance to accelerated UV exposure and subsequently, with up to 10% higher Brinell hardness values than reference wood. The proposed thermal treatment improves the durability of the finger-jointed wood through a more economically and environmental friendly method than traditional impregnation, with minimal degradative impact on the structural components of wood.

Unmanned Evaluation of Select Commercially Available Open Circuit Scuba Regulators for Cold Water Diving

DTIC Science & Technology

2010-04-01

Water Kit (dry system) installed as standard Abyss second stage with integrated 30-inch braided intermediate pressure hose as standard No user...diaphragm system) installed as standard Abyss second stage with integrated 30-inch braided intermediate pressure hose as standard No user adjustments...1st Stage Regulator with Abyss 2nd Stage and Integrated Intermediate Pressure Hose ..………………………….. A-2 A3 Modified Mares Proton Ice Extreme V32

75 FR 61432 - Takes of Marine Mammals Incidental to Specified Activities; Construction of the Parsons Slough...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-05

... a medium, such as air or water. Sound levels are compared to a reference sound pressure to identify the medium. For air and water, these reference pressures are ``re 20 microPa'' and ``re 1 microPa... produce a wide range of social signals, most occurring at relatively low frequencies (Southall et al...

46 CFR 160.050-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Incorporation by reference. 160.050-1 Section 160.050-1....050-1 Incorporation by reference. (a) Standard. This subpart makes reference to Federal Standard No... Service Center, General Services Administration, Washington, DC 20407. [USCG-1999-6216, 64 FR 53228, Oct...

Changing the "Normal Range" for Blood Pressure from 140/90 to 130/Any Improves Risk Assessment.

PubMed

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.

Quantifying patterns of change in marine ecosystem response to multiple pressures.

PubMed

Large, Scott I; Fay, Gavin; Friedland, Kevin D; Link, Jason S

2015-01-01

The ability to understand and ultimately predict ecosystem response to multiple pressures is paramount to successfully implement ecosystem-based management. Thresholds shifts and nonlinear patterns in ecosystem responses can be used to determine reference points that identify levels of a pressure that may drastically alter ecosystem status, which can inform management action. However, quantifying ecosystem reference points has proven elusive due in large part to the multi-dimensional nature of both ecosystem pressures and ecosystem responses. We used ecological indicators, synthetic measures of ecosystem status and functioning, to enumerate important ecosystem attributes and to reduce the complexity of the Northeast Shelf Large Marine Ecosystem (NES LME). Random forests were used to quantify the importance of four environmental and four anthropogenic pressure variables to the value of ecological indicators, and to quantify shifts in aggregate ecological indicator response along pressure gradients. Anthropogenic pressure variables were critical defining features and were able to predict an average of 8-13% (up to 25-66% for individual ecological indicators) of the variation in ecological indicator values, whereas environmental pressures were able to predict an average of 1-5 % (up to 9-26% for individual ecological indicators) of ecological indicator variation. Each pressure variable predicted a different suite of ecological indicator's variation and the shapes of ecological indicator responses along pressure gradients were generally nonlinear. Threshold shifts in ecosystem response to exploitation, the most important pressure variable, occurred when commercial landings were 20 and 60% of total surveyed biomass. Although present, threshold shifts in ecosystem response to environmental pressures were much less important, which suggests that anthropogenic pressures have significantly altered the ecosystem structure and functioning of the NES LME. Gradient response curves provide ecologically informed transformations of pressure variables to explain patterns of ecosystem structure and functioning. By concurrently identifying thresholds for a suite of ecological indicator responses to multiple pressures, we demonstrate that ecosystem reference points can be evaluated and used to support ecosystem-based management.

Optical-Fiber Power Meter Comparison Between NIST and PTB.

PubMed

Vayshenker, I; Haars, H; Li, X; Lehman, J H; Livigni, D J

2003-01-01

We describe the results of a comparison of reference standards between the National Institute of Standards and Technology (NIST-USA) and Physikalisch-Technische Bundesanstalt (PTB-Germany) at nominal wavelengths of 1300 nm and 1550 nm using an optical-fiber cable. Both laboratories used thermal detectors as reference standards. A novel temperature-controlled, optical-trap detector was used as a transfer standard to compare two reference standards. Measurement results showed differences of less than 1.5 × 10(-3), which is within the combined uncertainty for both laboratories.

A pulsed injection parahydrogen generator and techniques for quantifying enrichment.

PubMed

Feng, Bibo; Coffey, Aaron M; Colon, Raul D; Chekmenev, Eduard Y; Waddell, Kevin W

2012-01-01

A device is presented for efficiently enriching parahydrogen by pulsed injection of ambient hydrogen gas. Hydrogen input to the generator is pulsed at high pressure to a catalyst chamber making thermal contact with the cold head of a closed-cycle cryocooler maintained between 15 and 20K. The system enables fast production (0.9 standard liters per minute) and allows for a wide range of production targets. Production rates can be systematically adjusted by varying the actuation sequence of high-pressure solenoid valves, which are controlled via an open source microcontroller to sample all combinations between fast and thorough enrichment by varying duration of hydrogen contact in the catalyst chamber. The entire enrichment cycle from optimization to quantification and storage kinetics are also described. Conversion of the para spin-isomer to orthohydrogen in borosilicate tubes was measured at 8 min intervals over a period of 64 h with a 12 T NMR spectrometer. These relaxation curves were then used to extract initial enrichment by exploiting the known equilibrium (relaxed) distribution of spin isomers with linear least squares fitting to a single exponential decay curve with an estimated error less than or equal to 1%. This procedure is time-consuming, but requires only one sample pressurized to atmosphere. Given that tedious matching to external references are unnecessary with this procedure, we find it to be useful for periodic inspection of generator performance. The equipment and procedures offer a variation in generator design that eliminate the need to meter flow while enabling access to increased rates of production. These tools for enriching and quantifying parahydrogen have been in steady use for 3 years and should be helpful as a template or as reference material for building and operating a parahydrogen production facility. Copyright © 2011 Elsevier Inc. All rights reserved.

A Pulsed Injection Parahydrogen Generator and Techniques for Quantifying Enrichment

PubMed Central

Feng, Bibo; Coffey, Aaron M.; Colon, Raul D.; Chekmenev, Eduard Y.; Waddell, Kevin W.

2012-01-01

A device is presented for efficiently enriching parahydrogen by pulsed injection of ambient hydrogen gas. Hydrogen input to the generator is pulsed at high pressure to a catalyst chamber making thermal contact with the cold head of a closed cycle cryostat maintained between 15 and 20 K. The system enables fast production (0.9 standard liters per minute) and allows for a wide range of production targets. Production rates can be systematically adjusted by varying the actuation sequence of high-pressure solenoid valves, which are controlled via an open source microcontroller to sample all combinations between fast and thorough enrichment by varying duration of hydrogen contact in the catalyst chamber. The entire enrichment cycle from optimization to quantification and storage kinetics are also described. Conversion of the para spin-isomer to orthohydrogen in borosilicate tubes was measured at 8 minute intervals over a period of 64 hours with a 12 Tesla NMR spectrometer. These relaxation curves were then used to extract initial enrichment by exploiting the known equilibrium (relaxed) distribution of spin isomers with linear least squares fitting to a single exponential decay curve with an estimated error less than or equal to 1 %. This procedure is time-consuming, but requires only one sample pressurized to atmosphere. Given that tedious matching to external references are unnecessary with this procedure, we find it to be useful for periodic inspection of generator performance. The equipment and procedures offer a variation in generator design that eliminate the need to meter flow while enabling access to increased rates of production. These tools for enriching and quantifying parahydrogen have been in steady use for 3 years and should be helpful as a template or as reference material for building and operating a parahydrogen production facility. PMID:22188975

Reference values of one-point carotid stiffness parameters determined by carotid echo-tracking and brachial pulse pressure in a large population of healthy subjects.

PubMed

Vriz, Olga; Aboyans, Victor; Minisini, Rosalba; Magne, Julien; Bertin, Nicole; Pirisi, Mario; Bossone, Eduardo

2017-07-01

Arterial stiffness can predict cardiovascular events, and the aim of this study was to produce age- and sex-specific reference values for echo-tracking carotid stiffness in healthy subjects. A total of 900 subjects (500 males, mean age 45.8±19 years) were enrolled. Common carotid artery stiffness and compliance, using a high-definition echo-tracking ultrasound system, were evaluated. To compare stiffness parameters across the different age groups, individual scores were transformed into T-scores, indicating how many standard deviation (s.d.) units an individual's score was above or below the mean that was observed in the group including same-sex individuals aged 36 to 44 years. Carotid stiffness was similar among genders, except compliance, which was lower in women (P<0.0001). These characteristics were also maintained when the studied population was divided into seven age groups. Stiffness parameters increased significantly with age, but the opposite occurred for compliance. The T-score was found to increase significantly across all age groups, with a steeper increase in stiffness around the age of 60 years in women. For each T-score s.d., the corresponding carotid absolute values for arterial stiffness and compliance were obtained. In a multivariate model, carotid stiffness parameters were constantly and independently associated with age, mean arterial pressure, pulse pressure, heart rate and body mass index. Our study provides a normogram of carotid arterial stiffness and compliance indices obtained with the echo-tracking method in a large population of healthy subjects stratified by gender and age that can be used in clinical practice.

Echocardiographic evaluation of right ventricular stroke work index in advanced heart failure: a new index?

PubMed

Frea, Simone; Bovolo, Virginia; Bergerone, Serena; D'Ascenzo, Fabrizio; Antolini, Marina; Capriolo, Michele; Canavosio, Federico Giovanni; Morello, Mara; Gaita, Fiorenzo

2012-12-01

Right ventricular (RV) function plays a pivotal role in advanced heart failure patients, especially for screening those who may benefit from left ventricular assist device (LVAD) implantation. We introduce RV contraction pressure index (RVCPI) as a new echo-Doppler parameter of RV function. The accuracy of RVCPI in detecting RV failure was compared with the criterion standard, the RV stroke work index (RVSWI) obtained through right heart catheterization in advanced heart failure patients referred for heart transplantation or LVAD implantation. Right heart catheterization and echo-Doppler were simultaneously performed in 94 consecutive patients referred to our center for advanced heart failure (ejection fraction (EF) 24 ± 8.8%, 40% NYHA functional class IV). RV stroke volume and invasive pulmonary pressures were used to obtain RVSWI. Simplified RVCPI (sRVCPI) was derived as TAPSE × (RV - right atrial pressure gradient). Close positive correlation between sRVCPI and RVSWI was found (r = 0.68; P < .001). With logistic regression, we found that increased sRVCPI showed an independent reduced risk (odds ratio 0.98, 95% confidence interval [CI] 0.97-0.99; P = .016) for patients to present a depressed RVSWI (<0.25 mm Hg/L·m(2)). Simplified RVCPI showed high diagnostic accuracy (area under the receiver operating characteristic curve 0.94, 95% CI 0.89-0.99) and good sensitivity and specificity (92% and 85%, respectively) to predict depressed RVSWI with the use of a cutoff value of <400 mm·mm Hg. In patients with advanced heart failure, the new simple bedside sRVCPI closely correlated with RVSWI, providing an independent, noninvasive, and easy tool for the evaluation of RV function. Copyright © 2012 Elsevier Inc. All rights reserved.

The Efficacy of a Viscoelastic Foam Overlay on Prevention of Pressure Injury in Acutely Ill Patients: A Prospective Randomized Controlled Trial.

PubMed

Park, Kyung Hee; Park, Joohee

The purpose of this study was to compare a viscoelastic foam overlay (VEFO) to a standard hospital mattress for pressure injury (PI) prevention. We also compared interface pressures (IPs) of the VEFO to our facility's standard hospital mattress. Prospective, randomized controlled trial. Data analysis was based on 110 participants (55 in each group) who were 19 years or older, had a Braden Scale for Pressure Sore Risk score of 16 or less, and were cared for on a neurology, oncology, or pulmonology inpatient care unit. The research setting was the Samsung Medical Center in Seoul, South Korea. Participants were divided into 2 groups: the experimental group were based on a VEFO on top of the standard hospital mattress used in our facility. Participants in the control group were placed on a standard hospital mattress with/without air overlay. All patients were given standard nursing care for prevention of PI. Skin assessments were completed daily over a period of 2 weeks. In addition, we compared IPs of the standard hospital mattress and the VEFO in participants randomly allocated to the intervention group. Interface pressure was measured over the sacral/coccygeal area with subjects in the supine position. Pressures were measured immediately before and immediately following placement of the VEFO and just before data collection began. Data were collected between October 2013 and November 2014. Pressure injury incidence was compared between groups using the χ test, and IPs were compared using the paired t test. Pressure injury development was determined using the staging system described in guidelines from the National Pressure Ulcer Advisory Panel, European Pressure Ulcer Advisory Panel, and Pan Pacific Pressure Injury Alliance in 2014. Interface pressure was measured using a device manufactured for this purpose. The incidence of PI development was significantly lower in subjects assigned to the experimental group as compared to those in the control group (3.6%-27.3% over the 2-week data collection period; P = .001). The maximum IP was significantly lower on the VEFO with standard hospital mattress than on the standard hospital mattress (paired t = 8.87, P < .001). Patients managed with a VEFO had a significantly lower incidence of PI than those managed with a standard hospital mattress. Additional research is needed to further characterize the efficacy of the VEFO, its effect on PI healing, and its effect of PI prevention in high-risk populations such as critically ill patients.

Selective serotonin reuptake inhibitors and intraoperative blood pressure.

PubMed

van Haelst, Ingrid M M; van Klei, Wilton A; Doodeman, Hieronymus J; Kalkman, Cor J; Egberts, Toine C G

2012-02-01

The influence of selective serotonin reuptake inhibitors (SSRIs) on blood pressure is poorly understood. We hypothesized that if SSRIs have an influence on blood pressure, this might become manifest in changes in intraoperative blood pressure. We aimed to study the association between perioperative use of SSRIs and changes in intraoperative blood pressure by measuring the occurrence of intraoperative hyper- and hypotension. We conducted a retrospective observational follow-up study among patients who underwent elective primary total hip arthroplasty. The index group included users of SSRIs. The reference group included a random sample (ratio 1:3) of nonusers of an antidepressant agent. The outcome was the occurrence of intraoperative hypo- and hypertensive episodes (number, mean and total duration, and area under the curve (AUC)). The outcome was adjusted for confounding factors using regression techniques. The index group included 20 users of an SSRI. The reference group included 60 nonusers. Users of SSRIs showed fewer intraoperative hypotensive episodes, a shorter mean and total duration, and a smaller AUC when compared to the reference group. After adjustment for confounders, SSRI use was associated with a significantly shorter total duration of hypotension: mean difference of -29.4 min (95% confidence interval (CI) -50.4 to -8.3). Two users of an SSRI and two patients in the reference group had a hypertensive episode. Continuation of treatment with SSRIs before surgery was associated with a briefer duration of intraoperative hypotension.

Aeronautic Instruments. Section II : Altitude Instruments

NASA Technical Reports Server (NTRS)

Mears, A H; Henrickson, H B; Brombacher, W G

1923-01-01

This report is Section two of a series of reports on aeronautic instruments (Technical Report nos. 125 to 132, inclusive). This section discusses briefly barometric altitude determinations, and describes in detail the principal types of altimeters and barographs used in aeronautics during the recent war. This is followed by a discussion of performance requirements for such instruments and an account of the methods of testing developed by the Bureau of Standards. The report concludes with a brief account of the results of recent investigations. For accurate measurements of altitude, reference must also be made to thermometer readings of atmospheric temperature, since the altitude is not fixed by atmospheric pressure alone. This matter is discussed in connection with barometric altitude determination.

Natriuretic factor, a lasting enigma.

PubMed

Licht, A; Fine, L G; Bourgoignie, J J

1978-01-01

A gel filtration fraction of urine from patients with chronic uremia (natriuretic factor) decreases potential difference, net sodium flux and lumen to peritubular flux of sodium across the isolated rabbit cortical collecting tubule. These effects are consistent with the possibility that natriuretic factor represents a modulator of sodium excretion in the mammalian nephron. Natriuretic factor induces a dose-dependent inhibition of short-circuit current in the isolated toad bladder. By comparing the effects of natriuretic factor to those of a standard unit of reference, it may be possible to develop a quantitative assay for natriuretic factor. The acidic nature of natriuretic factor was confirmed by cation exchange column in a high pressure liquid chromatography system.

Combustion characteristics of various fuels during research octane number testing on an instrumented CFR F1/F2 engine

DOE PAGES

Kolodziej, Christopher P.; Wallner, Thomas

2017-04-01

The Cooperative Fuels Research (CFR) engine is the long-established standard for characterization of fuel knock resistance in spark-ignition internal combustion engines. Despite its measurements of RON and MON being widely used, there is little understanding of what governs the CFR octane rating for fuels of various chemical compositions compared to primary reference fuels (iso-octane and n-heptane). Some detailed combustion characteristics were measured on a highly instrumented CFR F1/F2 engine during RON testing of fuels with significantly different chemical composition. Our results revealed differences in the cylinder pressure and temperature conditions, as well as knocking characteristics.

RAWINPROC: Computer program for decommutating, interpreting, and interpolating Rawinsonde meteorological balloon sounding data

NASA Technical Reports Server (NTRS)

Staffanson, F. L.

1981-01-01

The FORTRAN computer program RAWINPROC accepts output from NASA Wallops computer program METPASS1; and produces input for NASA computer program 3.0.0700 (ECC-PRD). The three parts together form a software system for the completely automatic reduction of standard RAWINSONDE sounding data. RAWINPROC pre-edits the 0.1-second data, including time-of-day, azimuth, elevation, and sonde-modulated tone frequency, condenses the data according to successive dwells of the tone frequency, decommutates the condensed data into the proper channels (temperature, relative humidity, high and low references), determines the running baroswitch contact number and computes the associated pressure altitudes, and interpolates the data appropriate for input to ACC-PRD.

Combustion characteristics of various fuels during research octane number testing on an instrumented CFR F1/F2 engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolodziej, Christopher P.; Wallner, Thomas

The Cooperative Fuels Research (CFR) engine is the long-established standard for characterization of fuel knock resistance in spark-ignition internal combustion engines. Despite its measurements of RON and MON being widely used, there is little understanding of what governs the CFR octane rating for fuels of various chemical compositions compared to primary reference fuels (iso-octane and n-heptane). Some detailed combustion characteristics were measured on a highly instrumented CFR F1/F2 engine during RON testing of fuels with significantly different chemical composition. Our results revealed differences in the cylinder pressure and temperature conditions, as well as knocking characteristics.

40 CFR 60.482-8 - Standards: Pumps and valves in heavy liquid service, pressure relief devices in light liquid or...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards: Pumps and valves in heavy liquid service, pressure relief devices in light liquid or heavy liquid service, and connectors. 60.482-8... Standards: Pumps and valves in heavy liquid service, pressure relief devices in light liquid or heavy liquid...

Bidirectional association between parental child-feeding practices and body mass index at 4 and 7 y of age.

PubMed

Afonso, Lisa; Lopes, Carla; Severo, Milton; Santos, Susana; Real, Helena; Durão, Catarina; Moreira, Pedro; Oliveira, Andreia

2016-03-01

Evidence of the association between parental child-feeding practices and the child's body mass index (BMI) is controversial, and bidirectional effects have been poorly studied. We aimed to examine bidirectional associations between parental child-feeding practices and BMI at 4 and 7 y of age. This study included 3708 singleton children from the Generation XXI birth cohort with data on parental child-feeding practices and BMI at 4 and 7 y old. Feeding practices were assessed through a self-administered questionnaire by combining the Child Feeding Questionnaire and the Overt/Covert Control scale and then adapting it to Portuguese preschool children. Weight and height were measured according to standardized procedures, and age- and sex-specific BMI z scores were computed based on the WHO Growth References. Linear regression models were used to estimate the bidirectional associations between each practice and BMI z score. Crosslagged analyses were performed to compare the directions of those associations (the mean score of each practice and BMI z score at both ages were standardized to enable effect size comparisons). After adjustments, pressure to eat and overt control at 4 y of age were associated with a lower BMI z score 3 y later (β: -0.05; 95% CI: -0.08, -0.03 and β: -0.05; 95% CI: -0.09, -0.01, respectively). Regarding the opposite direction of association, a higher BMI z score at 4 y of age was significantly associated with higher levels of restriction and covert control at 7 y of age (β: 0.06; 95% CI: 0.03, 0.08 and β: 0.06; 95% CI: 0.04, 0.08, respectively) and with lower levels of pressure to eat (β: -0.17; 95% CI: -0.20, -0.15). The only bidirectional practice, pressure to eat, was more strongly influenced by the BMI z score than the reverse (βstandardized: -0.17 compared with βstandardized: -0.04; likelihood ratio test: P < 0.001). We found that parents both respond to and influence the child's weight; thus, this child-parent interaction should be considered in future research. © 2016 American Society for Nutrition.

Final report on key comparison EURAMET.M.P-K13 in the range 50 MPa to 500 MPa of hydraulic gauge pressure

NASA Astrophysics Data System (ADS)

Kocas, I.; Sabuga, W.; Bergoglio, M.; Eltaweel, A.; Korasie, C.; Farar, P.; Setina, J.; Waller, B.; Durgut, Y.

2015-01-01

The regional key comparison EURAMET.M.P-K13 for pressure measurements in liquid media from 50 MPa to 500 MPa was piloted by the TÜBİTAK UME Pressure Group Laboratories, Turkey. The transfer standard was a DH-Budenberg pressure balance with a free deformation piston-cylinder unit of 2 mm2 nominal effective area. Six laboratories from the EURAMET region, namely PTB, INRIM, SMU, IMT, NPL and UME, and two laboratories from the AFRIMETS region, NIS and NMISA participated in this comparison. Participant laboratories and countries are given in the bottom of the page. PTB participated in this comparison to provide a link to corresponding 500 MPa CCM key comparison CCM.P-K13. The results of all participants excepting NMISA and NPL were found to be consistent with the reference value of the actual comparison and of CCM.P-K13 within their claimed uncertainties (k = 2), at all pressures. Compared in pairs all laboratories with exception of NPL and NMISA demonstrate their agreement with each other within the expanded uncertainties (k = 2) at all pressures. The results are therefore considered to be satisfactory. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Controlled treatment of primary hypertension with propranolol and spironolactone. A crossover study with special reference to initial plasma renin activity.

PubMed

Karlberg, B E; Kågedal, B; Tegler, L; Tolagen, K; Bergman, B

1976-03-31

Twenty-seven patients with hypertension were randomly allocated to a 10 month crossover study. Treatment consisted of spironolactone (200 mg/day for 2 months), propranolol (320 mg/day for 2 months) and combined administration of both drugs at half the dosage. Between treatment periods placebo was given for 2 months. Fourteen patients were previously untreated. The average pretreatment blood pressure for the entire group was 188/114 +/- 16/7(mean +/- standard deviation) mm Hg supine and 188/118 +/- 20/9 mm Hg standing. Both spironolactone and propranolol reduced blood pressure significantly in both the supine and standing positions. Upright plasma renin activity was determined by radioimmunoassay of angiotensin I. The average initial level was 1.9 +/- 1.2 (range 0.4 to 5.0) ng/ml/hr. There was a close correlation between plasma renin activity and the effects of the drugs: With increasing renin level the response to propranolol was better whereas the opposite was true for spironolactone. The combination of spironolactone and propranolol decreased the blood pressure still further in the supine and standing positions, irrespective of initial plasma renin activity. All patients achieved a normal supine pressure. Blood pressure and plasma renin activity returned toward pretreatment values during placebo administration. It is concluded that pretreatment levels of plasma renin activity can predict the antihypertensive response to propranolol and spironolactone. The combination of the two drugs, which have different modes of action, will effectively reduce blood pressure in hypertension. The results support the concept that the renin-angiotensin-aldo-sterone system may be involved in primary hypertension.

Field Demonstration and Validation of a New Device for Measuring Water and Solute Fluxes at CFB Borden

DTIC Science & Technology

2006-11-01

All Quality Control Reference Materials are acquired only from authorized vendors or sources commonly used by U.S. EPA Regional Laboratories...Institue of Standards and Testing (NITS) Standard Reference Materials (SRM) or to the U.S. EPA Reference Standards. Working Standards The commercial...contaminants from clothing or equipment by blowing, shaking or any other means that may disperse material into the air is prohibited. 7.1.3. All disposable

The lunar semidiurnal air pressure tide in in-situ data and ECMWF reanalyses

NASA Astrophysics Data System (ADS)

Schindelegger, Michael; Dobslaw, Henryk

2016-04-01

A gridded empirical model of the lunar semidiurnal air pressure tide L2 is deduced through multiquadric interpolation of more than 2000 globally distributed tidal estimates from land barometers and moored buoys. The resulting climatology serves as an independent standard to validate the barometric L2 oscillations that are present in ECMWF's (European Centre for Medium-Range Weather Forecasts) global atmospheric reanalyses despite the omission of gravitational forcing mechanisms in the involved forecast routines. Inconsistencies between numerical and empirical L2 solutions are found to be small even though the reanalysis models typically underestimate equatorial peak pressures by 10-20% and produce slightly deficient tidal phases in latitudes south of 30°N. Through using a time-invariant reference surface over both land and water and assimilating marine pressure data without accounting for vertical sensor movements due to the M2 ocean tide, ECMWF-based tidal solutions are also prone to strong local artifacts. Additionally, the dependency of the lunar tidal oscillation in atmospheric analysis systems on the meteorological input data is demonstrated based on a recent ECMWF twentieth-century reanalysis (ERA-20C) which draws its all of its observational constraints from in-situ registrations of pressure and surface winds. The L2 signature prior to 1950 is particularly indicative of distinct observing system changes, such as the paucity of marine data during both World Wars or the opening of the Panama Canal in 1914 and the associated adjustment of commercial shipping routes.

Validation of the mobil-O-Graph: 24 h-blood pressure measurement device.

PubMed

Wei, Wolfgang; Tölle, Markus; Zidek, Walter; van der Giet, Markus

2010-08-01

Twenty-four-hour blood pressure measurement is of importance not only in the detection of hypertension but also in the detection of blood pressure changes in hypertensive and nonhypertensives over the day to identify, for example, nondipper hypertensives. This study describes the validation of the mobil-O-Graph according to the criteria of the British Hypertension Society (BHS). For each patient three readings obtained by the mobil-O-Graph were compared with auscultatory sphygmomanometric readings obtained by two trained clinicians. The sphygmomanometric reference measurements were alternated with the readings obtained by the device. Eighty-five patients (mean age 53.4+/-18.4 years) were recruited for the BHS protocol. Differences between blood pressure values of the test device and the mercury reading were calculated for each measurement. In the BHS validation procedure the mean differences of the observer readings and the test device were -2.2+/-6.7 (systolic) and -0.6+/-5.6 mmHg (diastolic) for observer 1 and -2.2+/-7.3 mmHg (systolic) and-0.4+/-6.1 mmHg (diastolic) for observer 2. The device achieved grade A for systolic and diastolic blood pressure for both the observers 1 and 2 leading to a final grade A/A. According to the BHS protocol the measurements of the device have to be considered 'very accurate and with no error of clinical relevance'. The device met the accuracy requirements of the BHS standard and can be recommended for clinical use.

[Assessment of patients with pressure sores admitted in a tertiary care center].

PubMed

Moro, Adriana; Maurici, Alice; do Valle, Juliana Barros; Zaclikevis, Viviane Renata; Kleinubing, Harry

2007-01-01

To determine the prevalence and analyze the profile of patients with pressure sores, focusing on risk factors, the patients' clinical characteristics at a tertiary care center, as well as stage and location of the lesions on the body. This was a cross sectional not controlled observational study, all patients admitted from April to June of 2005 were observed daily to identify all cases of pressure sores. The affected patients were evaluated by a standard questionnaire and the Scale of Braden was applied to define the risk of developing ulcers. Of the 690 patients admitted during the referred period, a prevalence of 5.9% of patients with lesions was observed, equivalent to 41 patients 63.9% of which were elderly and the average length of stay was 18 days. In the sample studied 41.5% of patients were found in the internal medicine section and the intensive care unit, ICU. The most common location for sores was the sacral area, corresponding to 73.1% of the patients, and stage II was the most frequent, observed in 58.5% of those patients. According to the Braden scale, most patients, 80.4%, had a high risk of developing pressure ulcers, compared to 9.7% of patients with moderate risk and 7.4% with low risk. The affected patients were at high risk of developing pressure sores. Prevalence of these lesions and the clinical and demographic profile of the affected patients are in accordance with the data in literature.

Economic Evaluations of Strategies to Prevent Hospital-Acquired Pressure Injuries.

PubMed

Ocampo, Wrechelle; Cheung, Amanda; Baylis, Barry; Clayden, Nancy; Conly, John M; Ghali, William A; Ho, Chester H; Kaufman, Jaime; Stelfox, Henry T; Hogan, David B

2017-07-01

To provide information from a review of literature about economic evaluations of preventive strategies for pressure injuries (PIs). This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. After participating in this educational activity, the participant should be better able to:1. Identify the purpose and methods used for this study.2. Compare costs and effectiveness related to preventative strategies for PIs. BACKGROUND: Pressure injuries (PIs) are a common and resource-intensive challenge for acute care hospitals worldwide. While a number of preventive strategies have the potential to reduce the cost of hospital-acquired PIs, it is unclear what approach is the most effective. The authors performed a narrative review of the literature on economic evaluations of preventive strategies to survey current findings and identify important factors in economic assessments. Ovid, MEDLINE, NHS Economic Evaluation Databases, and the Cochrane Database of Systematic ReviewsSELECTION CRITERIA: Potentially relevant original research articles and systematic reviews were considered. Selection criteria included articles that were written in English, provided data on cost or economic evaluations of preventive strategies of PIs in acute care, and published between January 2004 and September 2015. Data were abstracted from the articles using a standardized approach to evaluate how the items on the Consolidated Health Economic Evaluation Reporting Standards checklist were addressed. The searches identified 192 references. Thirty-three original articles were chosen for full-text reviews. Nineteen of these articles provided clear descriptions of interventions, study methods, and outcomes considered. Limitations in the available literature prevent firm conclusions from being reached about the relative economic merits of the various approaches to the prevention of PIs. The authors' review revealed a need for additional high-quality studies that adhere to commonly used standards of both currently utilized and emerging ways to prevent hospital-acquired PIs.

Animal behavior and well-being symposium: Farm animal welfare assurance: science and application.

PubMed

Rushen, J; Butterworth, A; Swanson, J C

2011-04-01

Public and consumer pressure for assurances that farm animals are raised humanely has led to a range of private and public animal welfare standards, and for methods to assess compliance with these standards. The standards usually claim to be science based, but even though researchers have developed measures of animal welfare and have tested the effects of housing and management variables on welfare within controlled laboratory settings, there are challenges in extending this research to develop on-site animal welfare standards. The standards need to be validated against a definition of welfare that has broad support and which is amenable to scientific investigation. Ensuring that such standards acknowledge scientific uncertainty is also challenging, and balanced input from all scientific disciplines dealing with animal welfare is needed. Agencies providing animal welfare audit services need to integrate these scientific standards and legal requirements into successful programs that effectively measure and objectively report compliance. On-farm assessment of animal welfare requires a combination of animal-based measures to assess the actual state of welfare and resource-based measures to identify risk factors. We illustrate this by referring to a method of assessing welfare in broiler flocks. Compliance with animal welfare standards requires buy-in from all stakeholders, and this will be best achieved by a process of inclusion in the development of pragmatic assessment methods and the development of audit programs verifying the conditions and continuous improvement of farm animal welfare.

40 CFR 61.242-8 - Standards: Pressure relief services in liquid service and connectors.

Code of Federal Regulations, 2012 CFR

2012-07-01

...: Pressure relief services in liquid service and connectors. (a) If evidence of a potential leak is found by visual, audible, olfactory, or any other detection method at pressure relief devices in liquid service... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Standards: Pressure relief services in...

40 CFR 61.242-8 - Standards: Pressure relief services in liquid service and connectors.

Code of Federal Regulations, 2014 CFR

2014-07-01

...: Pressure relief services in liquid service and connectors. (a) If evidence of a potential leak is found by visual, audible, olfactory, or any other detection method at pressure relief devices in liquid service... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Standards: Pressure relief services in...

40 CFR 61.242-8 - Standards: Pressure relief services in liquid service and connectors.

Code of Federal Regulations, 2010 CFR

2010-07-01

...: Pressure relief services in liquid service and connectors. (a) If evidence of a potential leak is found by visual, audible, olfactory, or any other detection method at pressure relief devices in liquid service... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Standards: Pressure relief services in...

40 CFR 61.242-8 - Standards: Pressure relief services in liquid service and connectors.

Code of Federal Regulations, 2011 CFR

2011-07-01

...: Pressure relief services in liquid service and connectors. (a) If evidence of a potential leak is found by visual, audible, olfactory, or any other detection method at pressure relief devices in liquid service... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Standards: Pressure relief services in...

40 CFR 61.242-8 - Standards: Pressure relief services in liquid service and connectors.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: Pressure relief services in liquid service and connectors. (a) If evidence of a potential leak is found by visual, audible, olfactory, or any other detection method at pressure relief devices in liquid service... 40 Protection of Environment 9 2013-07-01 2013-07-01 false Standards: Pressure relief services in...

A standard satellite control reference model

NASA Technical Reports Server (NTRS)

Golden, Constance

1994-01-01

This paper describes a Satellite Control Reference Model that provides the basis for an approach to identify where standards would be beneficial in supporting space operations functions. The background and context for the development of the model and the approach are described. A process for using this reference model to trace top level interoperability directives to specific sets of engineering interface standards that must be implemented to meet these directives is discussed. Issues in developing a 'universal' reference model are also identified.

Prevention of pressure ulcers with a static air support surface: A systematic review.

PubMed

Serraes, Brecht; van Leen, Martin; Schols, Jos; Van Hecke, Ann; Verhaeghe, Sofie; Beeckman, Dimitri

2018-06-01

The aims of this study were to identify, assess, and summarise available evidence about the effectiveness of static air mattress overlays to prevent pressure ulcers. The primary outcome was the incidence of pressure ulcers. Secondary outcomes included costs and patient comfort. This study was a systematic review. Six electronic databases were consulted: Cochrane Library, EMBASE, PubMed (Medline), CINAHL (EBSCOhost interface), Science direct, and Web of Science. In addition, a hand search through reviews, conference proceedings, and the reference lists of the included studies was performed to identify additional studies. Potential studies were reviewed and assessed by 2 independent authors based on the title and abstract. Decisions regarding inclusion or exclusion of the studies were based on a consensus between the authors. Studies were included if the following criteria were met: reporting an original study; the outcome was the incidence of pressure ulcer categories I to IV when using a static air mattress overlay and/or in comparison with other pressure-redistribution device(s); and studies published in English, French, and Dutch. No limitation was set on study setting, design, and date of publication. The methodological quality assessment was evaluated using the Critical Appraisal Skills Program Tool. Results were reported in a descriptive way to reflect the exploratory nature of the review. The searches included 13 studies: randomised controlled trials (n = 11) and cohort studies (n = 2). The mean pressure ulcer incidence figures found in the different settings were, respectively, 7.8% pressure ulcers of categories II to IV in nursing homes, 9.06% pressure ulcers of categories I to IV in intensive care settings, and 12% pressure ulcers of categories I to IV in orthopaedic wards. Seven comparative studies reported a lower incidence in the groups of patients on a static air mattress overlay. Three studies reported a statistical (P < .1) lower incidence compared with a standard hospital mattress (10 cm thick, density 35 kg/m 3 ), a foam mattress (15 cm thick), and a viscoelastic foam mattress (15 cm thick). No significant difference in incidence, purchase costs, and patient comfort was found compared with dynamic air mattresses. This review focused on the effectiveness of static air mattress overlays to prevent pressure ulcers. There are indications that these mattress overlays are more effective in preventing pressure ulcers compared with the use of a standard mattress or a pressure-reducing foam mattress in nursing homes and intensive care settings. However, interpretation of the evidence should be performed with caution due to the wide variety of methodological and/or reporting quality levels of the included studies. © 2018 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

The role of standards in the development and implementation of clinical laboratory tests: a domestic and global perspective.

PubMed

Michaud, Ginette Y

2005-01-01

In the field of clinical laboratory medicine, standardization is aimed at increasing the trueness and reliability of measured values. Standardization relies on the use of written standards, reference measurement procedures and reference materials. These are important tools for the design and validation of new tests, and for establishing the metrological traceability of diagnostic assays. Their use supports the translation of research technologies into new diagnostic assays and leads to more rapid advances in science and medicine, as well as improvements in the quality of patient care. The various standardization tools are described, as are the procedures by which written standards, reference procedures and reference materials are developed. Recent efforts to develop standards for use in the field of molecular diagnostics are discussed. The recognition of standardization tools by the FDA and other regulatory authorities is noted as evidence of their important role in ensuring the safety and performance of in vitro diagnostic devices.

Si-Traceable Scale for Measurements of Radiocarbon Concentration

NASA Astrophysics Data System (ADS)

Hodges, Joseph T.; Fleisher, Adam J.; Liu, Qingnan; Long, David A.

2017-06-01

Radiocarbon (^{14}C) dating of organic materials is based on measuring the ^{14}C/^{12}C atomic fraction relative to the nascent value that existed when the material was formed by photosynthetic conversion of carbon dioxide present in the atmosphere. This field of measurement has numerous applications including source apportionment of anthropogenic and biogenic fuels and combustion emissions, carbon cycle dynamics, archaeology, and forensics. Accelerator mass spectrometry (AMS) is the most widely used method for radiocarbon detection because it can measure extremely small amounts of radiocarbon (background of nominally 1.2 parts-per-trillion) with high relative precision (0.4 %). AMS measurements of radiocarbon are typically calibrated by reference to standard oxalic-acid (C_2H_2O_4) samples of known radiocativity that are derived from plant matter. Specifically, the internationally accepted absolute dating reference for so-called "modern-equivalent" radiocarbon is 95 % of the specific radioactivity in AD 1950 of the National Bureau of Standards (NBS) oxalic acid standard reference material and normalized to δ^{13}C_{VPDB} = 19 per mil. With this definition, a "modern-equivalent" corresponds to 1.176(70) parts-per-trillion of ^{14}C relative to total carbon content. As an alternative radiocarbon scale, we propose an SI-traceable method to determine ^{14}C absolute concentration which is based on linear Beer-Lambert-law absorption measurements of selected ^{14}C^{16}O_2 ν_3-band line areas. This approach is attractive because line intensities of chosen radiocarbon dioxide transitions can be determined by ab initio calculations with relative uncertainties below 0.5 %. This assumption is justified by the excellent agreement between theoretical values of line intensities and measurements for stable isotopologues of CO_2. In the case of cavity ring-down spectroscopy (CRDS) measurements of ^{14}C^{16}O_2 peak areas, we show that absolute, SI-traceable concentrations of radiocarbon can be determined through measurements of time, frequency, pressure and temperature. Notably, this approach will not require knowledge of the radiocarbon half-life and is expected to provide a stable scale that does not require an artifact standard. M. Stuiver and H. A. Polach, Radiocarbon 19, (1977) 355 O. L. Polyansky et al., Phys. Rev. Lett. 114, (2015) 243001

Measurement and Simulation of Spontaneous Raman Scattering Spectra in High-Pressure, Fuel-Rich H2-Air Flames

NASA Technical Reports Server (NTRS)

Kojima, Jun; Nguyen, Quang-Viet

2003-01-01

Rotational vibrational spontaneous Raman spectra (SRS) of H2, N2, and H2O have been measured in H2-air flames at pressures up to 30 atm as a first stem towards establishing a comprehensive Raman spectral database for temperatures and species in high-pressure combustion. A newly developed high-pressure burner facility provides steady, reproducible flames with a high degree of flow precision. We have obtained an initial set of measurements that indicate the spectra are of sufficient quality in terms of spectral resolution, wavelength coverage, and signal-to-noise ratio for use in future reference standards. The fully resolved Stokes and anti-Stokes shifted SRS spectra were collected in the visible wavelength range (400-700 nm) using pulse-stretched 532 nm excitation and a non-intensified CCD spectrograph with a high-speed shutter. Reasonable temperatures were determined via the intensity distribution of rotational H2 lines at stoichiometry and fuel-rich conditions. Theoretical Raman spectra of H2 were computed using a semi-classical harmonic-oscillator model with recent pressure broadening data and were compared with experimental results. The data and simulation indicated that high-J rotational lines of H2 might interfere with the N2 vibrational Q-branch lines, and this could lead to errors in N2-Raman thermometry based on the line-fitting method. From a comparison of N2 Q-branch spectra in lean H2 low-pressure (1.2 atm) and high-pressure (30 atm) flames, we found no significant line-narrowing or -broadening effects at the current spectrometer resolution of 0.04 nm.

Can an off-the-rack orthotic stiletto alter pressure and comfort scores in the forefoot, arch and heel?

PubMed

Penny, Jeannette Østergaard; Speedtsberg, Merete Brink; Kallemose, Thomas; Bencke, Jesper

2018-03-16

The study sought to investigate whether an orthotic stiletto could modulate the pressure and comfort under the forefoot, arch and heel that stiletto wearers experience. Twenty-two women participated. We measured the peak pressure and pressure-time integral for orthotic stilettos with built-in metatarsal pad, heel cup and arch support; standard stilettos without inlays; and trainers. Comfort was recorded during 3 × 3 working days. The orthotic stiletto exhibited lower metatarsal head1 (MTH) and MTH2+3 and heel pressures than the standard stiletto (p < .01), and a long second metatarsal increased MTH2+3 pressure (p < .01). The comfort in the forefoot and heel was higher in the orthotic stiletto than in the standard one (p < .01), and comfort in the forefoot was correlated to the pressure-time integral of MTH2+3 (p = .03) and not peak pressure. Off-the-rack orthotic stilettos can notably reduce plantar pressures and improve forefoot and heel comfort during everyday use. Practitioner Summary: Off-the-rack orthotic stilettos with built-in metatarsal pad, arch support and heel caps can lower the pressure under the heel and forefoot in comparison with a standard stiletto and can improve comfort during everyday use. Having a long second metatarsal is a risk factor for increased forefoot pressure.

Using Web-Based Questionnaires and Obstetric Records to Assess General Health Characteristics Among Pregnant Women: A Validation Study

PubMed Central

Schouten, Naomi PE; Merkus, Peter JFM; Verhaak, Chris M; Roeleveld, Nel; Roukema, Jolt

2015-01-01

Background Self-reported medical history information is included in many studies. However, data on the validity of Web-based questionnaires assessing medical history are scarce. If proven to be valid, Web-based questionnaires may provide researchers with an efficient means to collect data on this parameter in large populations. Objective The aim of this study was to assess the validity of a Web-based questionnaire on chronic medical conditions, allergies, and blood pressure readings against obstetric records and data from general practitioners. Methods Self-reported questionnaire data were compared with obstetric records for 519 pregnant women participating in the Dutch PRegnancy and Infant DEvelopment (PRIDE) Study from July 2011 through November 2012. These women completed Web-based questionnaires around their first prenatal care visit and in gestational weeks 17 and 34. We calculated kappa statistics (κ) and the observed proportions of positive and negative agreement between the baseline questionnaire and obstetric records for chronic conditions and allergies. In case of inconsistencies between these 2 data sources, medical records from the woman’s general practitioner were consulted as the reference standard. For systolic and diastolic blood pressure, intraclass correlation coefficients (ICCs) were calculated for multiple data points. Results Agreement between the baseline questionnaire and the obstetric record was substantial (κ=.61) for any chronic condition and moderate for any allergy (κ=.51). For specific conditions, we found high observed proportions of negative agreement (range 0.88-1.00) and on average moderate observed proportions of positive agreement with a wide range (range 0.19-0.90). Using the reference standard, the sensitivity of the Web-based questionnaire for chronic conditions and allergies was comparable to or even better than the sensitivity of the obstetric records, in particular for migraine (0.90 vs 0.40, P=.02), asthma (0.86 vs 0.61, P=.04), inhalation allergies (0.92 vs 0.74, P=.003), hay fever (0.90 vs 0.64, P=.001), and allergies to animals (0.89 vs 0.53, P=.01). However, some overreporting of allergies was observed in the questionnaire and for some nonsomatic conditions sensitivity of both measurement instruments was low. The ICCs for blood pressure readings ranged between 0.72 and 0.92 with very small mean differences between the 2 methods of data collection. Conclusions Web-based questionnaires can be used to validly collect data on many chronic disorders, allergies, and blood pressure readings among pregnant women. PMID:26081990

Using Web-Based Questionnaires and Obstetric Records to Assess General Health Characteristics Among Pregnant Women: A Validation Study.

PubMed

van Gelder, Marleen M H J; Schouten, Naomi P E; Merkus, Peter J F M; Verhaak, Chris M; Roeleveld, Nel; Roukema, Jolt

2015-06-16

Self-reported medical history information is included in many studies. However, data on the validity of Web-based questionnaires assessing medical history are scarce. If proven to be valid, Web-based questionnaires may provide researchers with an efficient means to collect data on this parameter in large populations. The aim of this study was to assess the validity of a Web-based questionnaire on chronic medical conditions, allergies, and blood pressure readings against obstetric records and data from general practitioners. Self-reported questionnaire data were compared with obstetric records for 519 pregnant women participating in the Dutch PRegnancy and Infant DEvelopment (PRIDE) Study from July 2011 through November 2012. These women completed Web-based questionnaires around their first prenatal care visit and in gestational weeks 17 and 34. We calculated kappa statistics (κ) and the observed proportions of positive and negative agreement between the baseline questionnaire and obstetric records for chronic conditions and allergies. In case of inconsistencies between these 2 data sources, medical records from the woman's general practitioner were consulted as the reference standard. For systolic and diastolic blood pressure, intraclass correlation coefficients (ICCs) were calculated for multiple data points. Agreement between the baseline questionnaire and the obstetric record was substantial (κ=.61) for any chronic condition and moderate for any allergy (κ=.51). For specific conditions, we found high observed proportions of negative agreement (range 0.88-1.00) and on average moderate observed proportions of positive agreement with a wide range (range 0.19-0.90). Using the reference standard, the sensitivity of the Web-based questionnaire for chronic conditions and allergies was comparable to or even better than the sensitivity of the obstetric records, in particular for migraine (0.90 vs 0.40, P=.02), asthma (0.86 vs 0.61, P=.04), inhalation allergies (0.92 vs 0.74, P=.003), hay fever (0.90 vs 0.64, P=.001), and allergies to animals (0.89 vs 0.53, P=.01). However, some overreporting of allergies was observed in the questionnaire and for some nonsomatic conditions sensitivity of both measurement instruments was low. The ICCs for blood pressure readings ranged between 0.72 and 0.92 with very small mean differences between the 2 methods of data collection. Web-based questionnaires can be used to validly collect data on many chronic disorders, allergies, and blood pressure readings among pregnant women.

POTENTIAL RADIOACTIVE POLLUTANTS RESULTING FROM EXPANDED ENERGY PROGRAMS

EPA Science Inventory

An effective environmental monitoring program must have a quality assurance component to assure the production of valid data. Quality assurance has many components: calibration standards, standard reference materials, standard reference methods, interlaboratory comparison studies...

Distribution of physical properties and timing of relative uplift in upper plate off Costa Rica: IODP Expedition 344

NASA Astrophysics Data System (ADS)

Saiki, A.; Hashimoto, Y.

2015-12-01

Evolution of physical properties in subduction zone is a key to understand lithification processes, location of decollement, and stress distribution. In this study, we examined the physical properties of sediments using on-board data and laboratory experimental data on sediments obtained off Costa Rica margin. Target sites are in the Integrate Ocean Drilling Program (IODP) Expedition 344 off Costa Rica, including reference sites (U1381 and U1414), mid-slope site (U1378, U1380) and upper-slope site (U1413). Seven samples from reference sites were analyzed. Laboratory experiments for velocity and porosity measurements were conducted with variation of effective pressure. Velocity-porosity relationships from on-board data and from laboratory experiments are comparable. The porosity-effective pressure curves under isotropic condition were converted to the curves under uniaxial condition (Teeuw, 1971). Using the normal consolidation curves under uniaxial stress conditions, we converted onboard porosity to effective pressure and fluid pressure. In reference sites, hydrostatic fluid pressure was estimated as expected as a reference sites, suggesting that porosity-effective pressure relationship was obtained correctly by experiments and it can be adapted to estimation of fluid pressure for the wedge sites. The porosity-effective pressure relationship under isotropic conditions were used for the estimation in wedge sites. In wedge sites, estimated pore pressures show lower than hydrostatic pressure, suggesting that onboard porosity was lower than that under normal compaction. The lower porosity can be caused by relative uplift from deeper portion. The amount of relative uplift can be estimated by differences in porosity-depth relationships between onboard data and experimental data. The amount of relative uplift for each site shows more than ~1000m up to ~5000m. The small error in porosity depth curve from experimental data makes relative uplift larger or smaller exponentially in the deeper portion. The increment of relative uplift, however, starts from about 1Ma in each site, suggesting some events were occurred at the timing. Laboratory experiments under differential stress should be conducted in the near future because smaller porosity is expected under differential stress conditions.

Final report on key comparison APMP.M.P-K3: Absolute pressure measurements in gas from 3 × 10-6 Pa to 9 × 10-4 Pa

NASA Astrophysics Data System (ADS)

Yoshida, H.; Arai, K.; Akimichi, H.; Hong, S. S.; Song, H. W.

2011-01-01

The results of a key comparison of ultra-high vacuum standards at two national metrology institutes (NMIJ/AIST and KRISS) are reported. This bilateral comparison was carried out from May 2010 to October 2010 within the framework of the Asia-Pacific Metrology Programme (APMP) to determine their degrees of equivalence at pressures in the range from 3 × 10-6 Pa to 9 × 10-4 Pa. The pilot institute was NMIJ/AIST. Two spinning rotor gauges and two hot cathode ionization gauges were used as the transfer standards. NMIJ/AIST used two calibration systems: the dynamic expansion system (NMIJ-DES) and two-stage flow-dividing system (NMIJ-TFS). KRISS used the dynamic expansion system. The transfer standards were sufficiently stable to meet the requirements of the comparison compared with those of previous international comparisons owing to some improvements of the protocol and the transfer standards. The ultra-high vacuum standards of NMIJ/AIST and KRISS were found to be equivalent within their claimed uncertainties in the range from 3 × 10-6 Pa to 9 × 10-5 Pa. The NMIJ-DES results, which have smaller uncertainty than NMIJ-TFS, were transferred to the corresponding CCM key comparison, CCM.P-K3, in the range from 3 × 10-6 Pa to 9 × 10-5 Pa and it is shown that the NMIJ values were equivalent to the CCM key comparison reference value within the claimed uncertainties. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Measuring Pressure Has a New Standard

NASA Technical Reports Server (NTRS)

2002-01-01

The Force-Balanced Piston Gauge (FPG) tests and calibrates instrumentation operating in the low pressure range. The system provides a traceable, primary calibration standard for measuring pressures in the range of near 0 to 15 kPa (2.2 psi) in both gauge and absolute measurement modes. The hardware combines a large area piston-cylinder with a load cell measuring the force resulting from pressures across the piston. The mass of the piston can be tared out, allowing measurement to start from zero. A pressure higher than the measured pressure, which keeps the piston centered, lubricates an innovative conical gap located between the piston and the cylinder, eliminating the need for piston rotation. A pressure controller based on the control of low gas flow automates the pressure control. DHI markets the FPG as an automated primary standard for very low-gauge and absolute pressures. DHI is selling the FPG to high-end metrology laboratories on a case by case basis, with a full commercial release to follow.