Contrapropagating Ultrasonic Flowmeter Using Clad Buffer Rods for High Temperature Measurements

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
D. R. França ◽  
C.-K. Jen ◽  
Y. Ono
Keyword(s):  
High Temperature ◽  
Temperature Variation ◽  
Signal To Noise Ratio ◽  
Flow Speed ◽  
Ultrasonic Flowmeter ◽  
Ultrasonic Signals ◽  
Transit Times ◽  
Temperature Application ◽  
The Difference ◽  
In Transit

This work proposes clad buffer rods driven by shear transducers as the main building block of contrapropagating ultrasonic flowmeters for high temperature application. It is demonstrated that the superior signal-to-noise ratio exhibited by clad buffer rods (compared with the reported nonclad counterparts) improves precision in transit time measurements, leading to more accurate flow speed determination. In addition, it is shown that clad buffer rods generate specific ultrasonic signals for temperature calibration of flowmeters, allowing temperature variation while still measuring accurately the flow speed. On the basis of these experimental results, a contrapropagating ultrasonic flowmeter was designed and installed in a heater machine for flow speed measurements of hot oil at temperatures near 130°C. For a temperature variation of 3°C, the difference between upstream and downstream ultrasonic transit times, which is proportional to the flow speed at a given temperature, was measured within 1 ns accuracy.

Transit time dispersion in the pulmonary arterial tree

1998 ◽  
Vol 85 (2) ◽  
pp. 565-574 ◽  
Author(s):  
Anne V. Clough ◽  
Steven T. Haworth ◽  
Christopher C. Hanger ◽  
Jerri Wang ◽  
David L. Roerig ◽  
...  
Keyword(s):  
Transit Time ◽  
Mean Transit Time ◽  
Arterial Tree ◽  
Lung Lobe ◽  
Transit Times ◽  
Pulmonary Capillary ◽  
Time Dispersion ◽  
Pulmonary Arterial ◽  
The Difference ◽  
In Transit

Knowledge of the contributions of arterial and venous transit time dispersion to the pulmonary vascular transit time distribution is important for understanding lung function and for interpreting various kinds of data containing information about pulmonary function. Thus, to determine the dispersion of blood transit times occurring within the pulmonary arterial and venous trees, images of a bolus of contrast medium passing through the vasculature of pump-perfused dog lung lobes were acquired by using an X-ray microfocal angiography system. Time-absorbance curves from the lobar artery and vein and from selected locations within the intrapulmonary arterial tree were measured from the images. Overall dispersion within the lung lobe was determined from the difference in the first and second moments (mean transit time and variance, respectively) of the inlet arterial and outlet venous time-absorbance curves. Moments at selected locations within the arterial tree were also calculated and compared with those of the lobar artery curve. Transit times for the arterial pathways upstream from the smallest measured arteries (200-μm diameter) were less than ∼20% of the total lung lobe mean transit time. Transit time variance among these arterial pathways (interpathway dispersion) was less than ∼5% of the total variance imparted on the bolus as it passed through the lung lobe. On average, the dispersion that occurred along a given pathway (intrapathway dispersion) was negligible. Similar results were obtained for the venous tree. Taken together, the results suggest that most of the variation in transit time in the intrapulmonary vasculature occurs within the pulmonary capillary bed rather than in conducting arteries or veins.

scholarly journals Atmospheric Characterization via Broadband Color Filters on the PLAnetary Transits and Oscillations of stars (PLATO) Mission

2020 ◽  
Author(s):  
John Lee Grenfell ◽  
Mareike Godolt ◽  
Juan Cabrera ◽  
Ludmila Carone ◽  
Antonio Garcia Munoz ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Space Mission ◽  
Atmospheric Composition ◽  
Phase Curve ◽  
Wavelength Interval ◽  
Hot Jupiters ◽  
The Difference ◽  
In Transit ◽  
Color Filters ◽  
Planetary Transits

<p>We assess broadband color filters for the two fast cameras on the PLAnetary Transits and Oscillations (PLATO) of stars space mission with respect to exoplanetary atmospheric characterization. We focus on Ultra Hot Jupiters and Hot Jupiters placed 25pc and 100pc away from the Earth and warm Super-Earths placed 10pc and 25pc away. Our analysis takes as input literature values for the difference in transit depth between the broadband lower (500-675nm) wavelength interval (hereafter referred to as ”blue“) and the upper (675-1125nm) broadband wavelength interval (hereafter referred to as ”red“) for transmission, occultation and phase curve analyses. Planets orbiting main sequence central stars with stellar classes F, G, K and M are investigated. We calculate the signal-to-noise ratio with respect to photon and instrument noise for detecting the difference in transit depth between the two spectral intervals. Results suggest that bulk atmospheric composition and planetary geometric albedos could be detected for (Ultra) Hot Jupiters up to ~100pc (~25pc) with strong (moderate) Rayleigh extinction. Phase curve information could be extracted for Ultra Hot Jupiters orbiting K and G dwarf stars up to 25pc away. For warm Super-Earths, basic atmospheric types (primary and water-dominated) and the presence of sub-micron hazes in the upper atmosphere could be distinguished for up to a handful of cases up to ~10pc (manuscript accepted in Experimental Astronomy).</p>

Intercontinental and transcontinental mail transit times from Europe to Berkeley, 1892 to 1941

1986 ◽  
Vol 13 (2) ◽  
pp. 141-154 ◽  
Author(s):  
RUDOLF SCHMID
Keyword(s):  
Transit Times ◽  
In Transit

SUMMARY Mail transit times from Germany to Berkeley, California, are computed for issues of the current awareness journals Botanisches Centralblatt (1880–1945) and the interdisciplinary Naturae Novitates (1879–1944). Issues of the former for 1892 to 1902 averaged 29.3 days (31.2 days if abnormal times are included) in transit from Kassel to Berkeley, with many issues (92) requiring only 20 to 25 days for intercontinental and transcontinental transit. Mail transit of Naturae Novitates from Berlin to Berkeley averaged 40.7 days (42 if abnormal times are included) per issue for 1903 to 1916 and 44 days (51.1 days) per issue for 1922 to 1941 (cumulatively averaging 42 days, or 45.9 days for abnormal times), with some issues in 1906 requiring only 11-12 days for intercontinental and transcontinental transit. A smaller sampling for Nature for 1923 and 1930 gave averages of, respectively, 21.5 and 22.4 days, with a minimum of 14 days in both years. These times are consistent with known transatlantic and transcontinental, ship and rail, mail transit times for these periods, as tabulated from various sources. For perspective, early intercontinental and transcontinental air transit times and pre-1892 intercontinental ship transit times are also tabulated.

Spring and piston system for high temperature application

1997 ◽  
Author(s):  
R. Spivey ◽  
S. Breeding ◽  
J. Andrews ◽  
D. Stefanescu ◽  
S. Sen ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Application ◽  
Piston System ◽  
Temperature Application

scholarly journals Evaluation on the Bond Capacity of the Fire-Protected FRP Bonded to Concrete Under High Temperature

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Soo-yeon Seo ◽  
Jong-wook Lim ◽  
Su-hyun Jeong
Keyword(s):  
High Temperature ◽  
Critical Temperature ◽  
Temperature Variation ◽  
Fire Resistance ◽  
Fire Protection ◽  
Element Analysis ◽  
External Temperature ◽  
Near Surface ◽  
Board Type ◽  
The Face

AbstractTo figure out the change in the reinforcing effect of FRP system used for the retrofit of RC beam when it is exposed to high temperature, it is required to evaluate not only the behavior of the entire beam, but also the bond performance at anchorage zone through a bond test according to the increase of external temperature. Moreover, the study to find various fire-protection methods is necessary to prevent the epoxy from reaching the critical temperature during an exposure to high temperature. In this manner, the fire-resistance performances of externally bonded (EB) FRP and near-surface-mounted (NSM) FRP to concrete block were evaluated by high-temperature exposure tests after performing a fire-protection on the surface in this paper. Board-type insulation with mortar was considered for the fire-protection of FRP system. After the fire-protection of the FRPs bonded to concrete blocks, an increasing exposure temperature was applied to the specimens with keeping a constant shear bond stress between concrete and the FRP. Based on the result, the temperature when the bond strength of the FRP disappears was evaluated. In addition, a finite element analysis was performed to find a proper method for predicting the temperature variation of the epoxy which is fire-protected with board-type insulation during the increase of external temperature. As a result of the test, despite the same fire-protection, NSM specimens were able to resist 1.54–2.08 times higher temperature than EB specimens. In the design of fire-protection of FRP system with the board-type insulation, it is necessary to consider the transfer from sides as well as the face with FRP. If there is no insulation of FP boards on the sides, the epoxy easily reaches its critical temperature by the heat penetrated to the sides, and increasing the thickness of the FP board alone for the face with FRP does not increase the fire-resistance capacity. As a result of the FE analysis, the temperature variation at epoxy can be predicted using the analytical approach with the proper thermal properties of FP mortar and board.

scholarly journals The Balloon-Borne Investigation of Temperature and Speed of Electrons in the Corona (BITSE): Mission Description and Preliminary Results

Solar Physics ◽  
2021 ◽  
Vol 296 (1) ◽  
Author(s):  
N. Gopalswamy ◽  
J. Newmark ◽  
S. Yashiro ◽  
P. Mäkelä ◽  
N. Reginald ◽  
...  
Keyword(s):  
Heliocentric Distance ◽  
Signal To Noise Ratio ◽  
Flow Speed ◽  
Science Data ◽  
Uncertainty Interval ◽  
Heliospheric Observatory ◽  
Flash Storage ◽  
Goddard Space Flight Center ◽  
Good Agreement ◽  
Polarization Camera

AbstractWe report on the Balloon-borne Investigation of Temperature and Speed of Electrons in the corona (BITSE) mission launched recently to observe the solar corona from $\approx 3$ ≈ 3  Rs to 15 Rs at four wavelengths (393.5, 405.0, 398.7, and 423.4 nm). The BITSE instrument is an externally occulted single stage coronagraph developed at NASA’s Goddard Space Flight Center in collaboration with the Korea Astronomy and Space Science Institute (KASI). BITSE used a polarization camera that provided polarization and total brightness images of size $1024 \times 1024$ 1024 × 1024 pixels. The Wallops Arc Second Pointer (WASP) system developed at NASA’s Wallops Flight Facility (WFF) was used for Sun pointing. The coronagraph and WASP were mounted on a gondola provided by WFF and launched from the Fort Sumner, New Mexico station of Columbia Scientific Balloon Facility (CSBF) on September 18, 2019. BITSE obtained 17,060 coronal images at a float altitude of $\approx \mbox{128,000}$ ≈ 128,000 feet ($\approx 39$ ≈ 39  km) over a period of $\approx 4$ ≈ 4  hrs. BITSE flight software was based on NASA’s core Flight System, which was designed to help develop flight quality software. We used EVTM (Ethernet Via Telemetry) to download science data during operations; all images were stored on board using flash storage. At the end of the mission, all data were recovered and analyzed. Preliminary analysis shows that BITSE imaged the solar minimum corona with the equatorial streamers on the east and west limbs. The narrow streamers observed by BITSE are in good agreement with the geometric properties obtained by the Solar and Heliospheric Observatory (SOHO) coronagraphs in the overlapping physical domain. In spite of the small signal-to-noise ratio ($\approx 14$ ≈ 14 ) we were able to obtain the temperature and flow speed of the western steamer. In the heliocentric distance range 4 – 7 Rs on the western streamer, we obtained a temperature of $\approx 1.0\pm 0.3$ ≈ 1.0 ± 0.3  MK and a flow speed of $\approx 260$ ≈ 260  km s−1 with a large uncertainty interval.

scholarly journals The Performance of Filava-Polysiloxane, Silres® H62C Composite in High Temperature Application

2021 ◽  
Vol 5 (6) ◽  
pp. 144
Author(s):  
Klaudio Bari ◽  
Thozhuvur Govindaraman Loganathan
Keyword(s):  
High Temperature ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Fire Retardant ◽  
Bending Test ◽  
Ongoing Research ◽  
Flexural Testing ◽  
Temperature Application ◽  
High Temperature Tensile ◽  
In Fire

The research aim is to investigate the performance of novel enriched mineral fibres (Filava) in polysiloxane SLIRES H62 resin. Specimens were manufactured using a vacuum bagging process and oven cured at 250 °C. Specimens were prepared for flexural testing according to BS EN ISO 14125:1998 to obtain flexural strength, modulus, and elongation. The mechanical strength was compared to similar composites, with the aim of determining composite performance index. The flexural modulus (9.7 GPa), flexural strength (83 MPa), and flexural strain (2.9%) were obtained from a three-point bending test. In addition, the study investigates the thermal properties of the composite using a state-of-art Zwick Roell high temperature tensile rig. The results showed Filava/Polysiloxane Composites had an ultimate tensile strength 400 MPa, Young’s modulus 16 GPa and strain 2.5% at 1000 °C, and no smoke and ash were observed during pyrolysis. Ongoing research is currently taking place to use Filava-H62 in fire-retardant enclosure for lithium-ferro-phosphate Batteries used in electric trucks.

High-Temperature Brazing Molybdenum

2012 ◽  
Vol 586 ◽  
pp. 69-73
Author(s):  
Chia Chen Lin ◽  
Cheng Han Lee ◽  
Ren Kae Shiue ◽  
Hsiou Jeng Shy
Keyword(s):  
High Temperature ◽  
Intermetallic Phase ◽  
High Temperature Application ◽  
Three Point Bending ◽  
Brazed Joints ◽  
Temperature Application ◽  
Titanium Foils

High-temperature brazing molybdenum using palladium and titanium foils have been investigated in the experiment. Successful brazed joints are achieved from using the palladium filler foil. Brazed joints are fully dense and free of any intermetallic phase. Three point bending strengths of 246 and 233 MPa are obtained from joints using 100 m thick palladium filler foil brazed at 1580 and 1610 oC for 600 s, respectively. The application of palladium filler foil shows potential in brazing molybdenum for high-temperature application.

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