Comparison of xylem flow velocities determined by MRI and a non-invasive heat pulse technique in Golden Alder and Silver Birch

Abstract In this work, an efficient non-invasive terahertz pulse technique is proposed and investigated to determine the thickness and refractive index of each layer in an optically thick stratified media. A closed form formulations are derived for simultaneous extraction of the thickness and complex refractive index of each layer with the help of primary reflected signals from the multilayered structure. The proposed technique is numerically tested using a full wave electromagnetic simulator and is experimental verified in the millimeter wave frequency range by utilizing the power peaks corresponding to the primary reflected signals. The numerical and measured results of multilayered samples under test are in good agreement with the reference data. The proposed terahertz pulse technique can be used for non-destructive testing of the multilayered system existing in various industries.

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Ulnar Artery Aneurysm and Repair

Journal for Vascular Ultrasound ◽

10.1177/1544316718763394 ◽

2018 ◽

Vol 42 (1) ◽

pp. 30-32 ◽

Cited By ~ 1

Author(s):

Maria T. Cardinale ◽

Steven P. Posner ◽

Kathyrn F. Abernathy

Keyword(s):

Artery Aneurysm ◽

Ulnar Artery ◽

Non Invasive ◽

Duplex Imaging ◽

Pulsatile Mass ◽

Normal Blood Flow ◽

Hypothenar Eminence ◽

Blood Flow Velocities ◽

Flow Velocities

This is a case study of a patient who was presented to the emergency room with ischemia of the left third, fourth and fifth fingers and a pulsatile mass in the hypothenar eminence. Non-invasive arterial exam of the upper extremities was performed bilaterally which resulted in normal pressures and normal blood flow velocities. The arterial duplex imaging was also normal in the subclavian, axillary, brachial, radial and ulnar arteries and also demonstrated triphasic Doppler flow velocities. The technologist scanned distal to the wrist where a branch of the ulnar artery along with the aspect of the palmer arch surface revealed a true aneuryms with both antegrade and retrograde flow. The patient was infused tissue plasminogen activator (TPA) for a total of 72 hours with eventual recanalization of the thrombosed aneurysm. Due to the high risk of limb threat the patient underwent a successful resection of the left ulnar artery aneurysm with vein patch.

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Determining Soil Water Flux and Pore Water Velocity by a Heat Pulse Technique

Soil Science Society of America Journal ◽

10.2136/sssaj2000.642552x ◽

2000 ◽

Vol 64 (2) ◽

pp. 552-560 ◽

Cited By ~ 91

Author(s):

T. Ren ◽

G. J. Kluitenberg ◽

R. Horton

Keyword(s):

Soil Water ◽

Pore Water ◽

Water Flux ◽

Heat Pulse ◽

Water Velocity ◽

Pulse Technique ◽

Pore Water Velocity ◽

Soil Water Flux

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A negative heat pulse technique (for phonon studies)

Journal of Physics E Scientific Instruments ◽

10.1088/0022-3735/7/9/003 ◽

1974 ◽

Vol 7 (9) ◽

pp. 701-702

Author(s):

A K R Bromley ◽

J K Wigmore

Keyword(s):

Heat Pulse ◽

Pulse Technique

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Measuring peat moisture content using the dual-probe heat pulse technique

Soil Research ◽

10.1071/sr00108 ◽

2002 ◽

Vol 40 (1) ◽

pp. 177 ◽

Cited By ~ 24

Author(s):

David I. Campbell ◽

Claire E. Laybourne ◽

Ian J. Blair

Keyword(s):

Moisture Content ◽

Gravimetric Method ◽

Heat Pulse ◽

Time Domain Reflectometry ◽

Peat Soils ◽

Pulse Technique ◽

Mineral Soils ◽

Reference Measurements ◽

High Level ◽

Dual Probe

The dual-probe heat pulse (DPHP) technique for measuring soil volumetric moisture content (Θv) is evaluated for use in peat soils with very high organic matter contents. The method has a greater sensitivity in peat soils compared with mineral soils and excellent resolution is possible, even at moisture contents as high as 90&percnt; by volume. Advantages of the DPHP technique are that sensors are simple to construct from inexpensive parts and calibration is not required since the method is based on a physical model of radial heat flow in soil. A multiplexer method was developed to allow multiple probes to be deployed in the field. DPHP measurements of Θv for small peat samples compared closely to reference measurements made using the gravimetric method, and in the field were similar to results obtained using a time domain reflectometry (TDR) method. Peat soils display a high level of spatial variation in Θv at the scales of both DPHP and TDR probes, so that multiple probes of each type are required for adequate spatial sampling of Θv. Rapid changes in peat moisture content were recorded following rainfall infiltration events yet moisture storage did not remain elevated following rainfall, even for peat that was very dry. wetlands, hydrology, soil moisture.

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Pattern of Seasonal Water Use of Asian Pears Determined by Lysimeters and the Heat-pulse Technique

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.118.5.562 ◽

1993 ◽

Vol 118 (5) ◽

pp. 562-569 ◽

Cited By ~ 6

Author(s):

Horst W. Caspari ◽

M. Hossein Behhoudian ◽

David J. Chalmers ◽

A. Richard Renquist

Keyword(s):

Water Potential ◽

Surface Area ◽

Water Use ◽

Late Summer ◽

Heat Pulse ◽

Rapid Decline ◽

Pulse Technique ◽

Pyrus Serotina ◽

Crop Coefficients ◽

Seasonal Water Use

Seasonal water use data are presented for 4-year-old Pyrus serotina Rehder cv. Hosui growing in drainage lysimeters and trained onto a Tatura trellis. Weekly water use (WU) was calculated using the mass balance approach. For 8 consecutive weeks during late summer, instantaneous WU was also measured by the compensation heat-pulse technique for measuring sap flow. Although good agreement was found between the two methods for 4 weeks after probe installation, discrepancies increased after this time. Water use was highest in early to mid-January in New Zealand, averaging ≈8 liters/tree per day, or 2 liters·m-2 canopy surface area/day. Total water use over the growing season was 1070 liters/tree, or 245 liters·m-2 canopy surface area. The correlation coefficient between weekly WU and evaporation from a nearby Class A pan was 0.81 for the season. Weekly crop coefficients thus calculated for the well-watered trees ranged from 0.15 to 0.55 and 0.20 to 0.83 when calculated using canopy surface area and projected ground area, respectively. Low values were due to low values of canopy leaf area early in the season. Withholding irrigation during three periods resulted in a gradual decline in water use. Water-stressed trees had a lower predawn water potential than fully irrigated trees. This pattern was followed by a more-rapid decline during the morning, and a slower recovery during late afternoon and early evening. Midday leaf water potential never fell below -2.5 MPa.

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