Use of Permanent Resistivity and Transient Pressure Measurement for Time-Lapse Saturation Mapping

Pumps and valves are primary power and control devices in water supply piping systems. A collaborative operational scheme is very important for a series pump–valve system to decrease the transient pressure during the startup process. In order to analyze the influence of the operational time differences between the pump and the valve on the transient process, a complicated pump system was numerically simulated using the method of characteristics (MOC). The boundary conditions of the pump and the valve were separately established by equating an auxiliary element in the discrete mesh. The transient pressure, pump speed, and flow were studied for various time differences and the valve opening process for the series pump–valve startup process. Furthermore, an optimal collaborative scheme was presented to prevent inverse rotation and overpressure during the startup process. The results show that a reasonable time-lapse and fast opening can prevent the backward flow and reverse rotation, as well as control the transient maximal pressure during the system startup process.

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Wave separation and pipeline condition assessment using in-pipe fibre optic pressure sensors

Journal of Hydroinformatics ◽

10.2166/hydro.2019.051 ◽

2019 ◽

Vol 21 (2) ◽

pp. 371-379 ◽

Cited By ~ 4

Author(s):

He Shi ◽

Jinzhe Gong ◽

Peter R. Cook ◽

John W. Arkwright ◽

Gretel M. Png ◽

...

Keyword(s):

Pressure Measurement ◽

Sensor Array ◽

Pressure Sensors ◽

Condition Assessment ◽

Pressure Waves ◽

Fibre Optic ◽

Transient Pressure ◽

Water Pipes ◽

Wave Separation ◽

Close Proximity

Abstract The use of two pressure transducers in close proximity can enable the separation of the directional travelling pressure waves in pipelines. However, the implementation of this measurement strategy in real water pipes is difficult due to the lack of closely located access points. This paper reports the use of a customised in-pipe fibre optic pressure sensor array for hydraulic transient wave separation and pipeline condition assessment. The fibre optic pressure sensor array can be inserted into a pressurised pipeline through a single access point. The array consists of multiple fibre Bragg grating (FBG)-based pressure sensors in close proximity (∼0.5 m apart). A previously developed wave separation algorithm is adapted to analyse the transient pressure measurement from the FBG sensors. The resultant directional pressure waves are then used to detect pipe sections with a thinner wall thickness. A challenge is the influence of the in-pipe fibre optic sensing cable on the transient pressure measurement. The impact is analysed and adjustments to the pipeline condition assessment algorithm are undertaken to resolve the issue. The successful experimental application verifies the usefulness of the in-pipe fibre optic sensor array, which can facilitate transient-based pipeline condition assessment for buried water pipes with limited access points.

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8 TRANSIENT PRESSURE MEASUREMENT

Education + Training ◽

10.1108/eb015308 ◽

1963 ◽

Vol 5 (7) ◽

pp. 321-321

Author(s):

W.A. Pullman

Keyword(s):

Pressure Measurement ◽

Transient Pressure

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Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084120 ◽

1978 ◽

Vol 36 (2) ◽

pp. 650-651

Author(s):

Raul I. Garcia ◽

Evelyn A. Flynn ◽

George Szabo

Keyword(s):

Direct Injection ◽

Skin Pigmentation ◽

Freeze Fracture ◽

Pigment Granule ◽

Time Lapse ◽

Ultrastructural Level ◽

Lanthanum Tracer ◽

A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

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High-voltage Electron Microscopy of astroglial cell whole mounts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143201 ◽

1986 ◽

Vol 44 ◽

pp. 316-317

Author(s):

J.N. Turner ◽

W.G. Shain ◽

V. Madelian ◽

R.A. Grassucci ◽

D.L. Forman

Keyword(s):

Electron Microscopy ◽

High Voltage ◽

Time Lapse ◽

Astroglial Cells ◽

High Voltage Electron Microscopy ◽

Rat Glioma ◽

Voltage Electron ◽

High Voltage Electron ◽

Nervous System Function ◽

Beta Adrenergic Agonist

Homogeneous cultures of astroglial cells have proved useful for studying biochemical, pharmacological, and toxicological responses of astrocytes to effectors of central nervous system function. LRM 55 astroglial cells, which were derived from a rat glioma and maintained in continuous culture, exhibit a number of astrocyte properties (1-3). Stimulation of LRM 55s and astrocytes in primary cell cultures with the beta-adrenergic agonist isoproterenol results in rapid changes of morphology. Studies with time lapse video light microscopy (VLM) and high-voltage electron microscopy (HVEM) have been correlated to changes in intracellular levels of c-AMP. This report emphasizes the HVEM results.

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Use of Permanent Resistivity and Transient Pressure Measurement for Time-Lapse Saturation Mapping