Faculty Opinions recommendation of Application of a single-solute non-steady-state phloem model to the study of long-distance assimilate transport.

Electrospray thruster life and mission performance are strongly influenced by grid impingement, the extent of which can be correlated with emission modes that occur at steady-state extraction voltages, and thruster command transients. Most notably, we experimentally observed skewed cone-jet emission during steady-state electrospray thruster operation, which leads to the definition of an additional grid impingement mechanism that we termed “tilted emission”. Long distance microscopy was used in conjunction with high speed videography to observe the emission site of an electrospray thruster operating with an ionic liquid propellant (EMI-Im). During steady-state thruster operation, no unsteady electrohydrodynamic emission modes were observed, though the conical meniscus exhibited steady off-axis tilt of up to 15°. Cone tilt angle was independent over a wide range of flow rates but proved strongly dependent on extraction voltage. For the geometry and propellant used, the optimal extraction voltage was near 1.6 kV. A second experiment characterized transient emission behavior by observing startup and shutdown of the thruster via flow or voltage. Three of the four possible startup and shutdown procedures transition to quiescence within ∼475 μs, with no observed unsteady modes. However, during voltage-induced thruster startup, unsteady electrohydrodynamic modes were observed.

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Regulation and function of extracellular invertase from higher plants in relation to assimilate partitioning, stress responses and sugar signalling

Functional Plant Biology ◽

10.1071/pp00001 ◽

2000 ◽

Vol 27 (9) ◽

pp. 815 ◽

Cited By ~ 13

Author(s):

Thomas Roitsch ◽

Rainer Ehneß ◽

Marc Goetz ◽

Bettina Hause ◽

Markus Hofmann ◽

...

Keyword(s):

Stress Responses ◽

Higher Plants ◽

Assimilate Transport ◽

Signal Molecules ◽

Assimilate Partitioning ◽

Long Distance ◽

Phloem Unloading ◽

Intracellular Location ◽

Carbohydrate Partitioning ◽

Extracellular Invertase

This paper originates from a presentation at the International Conference on Assimilate Transport and Partitioning, Newcastle, NSW, August 1999 Carbohydrates are synthesised in photosynthetically active source tissues and exported, in most species in the form of sucrose, to photosynthetically less active or inactive sink tissues. Sucrose hydrolysis at the site of utilisation contributes to phloem unloading. This phenomenon links sink metabolism with phloem transport to, and partitioning between, sinks. Invertases catalyse the irreversible hydrolysis of sucrose and thus are expected to contribute to carbohydrate partitioning. Different invertase isoenzymes may be distinguished based on their intracellular location, their isoelectric points and pH optima. Extracellular, cell-wall-bound invertase is uniquely positioned to supply carbohydrates to sink tissues via an apoplasmic pathway, and links the transport sugar sucrose to hexose transporters. A number of studies demonstrate an essential function of this invertase isoenzyme for phloem unloading, carbohydrate partitioning and growth of sink tissues. Extracellular invertases were shown to be specifically expressed under conditions that require a high carbohydrate supply to sink tissues. Further, their expression is upregulated by a number of stimuli that affect source–sink relations. Substrate and reaction products of invertases are not only nutri-ents, but also signal molecules. Like hormones and in combination with hormones and other stimuli, they can regu-late many aspects of plant development from gene expression to long-distance nutrient allocation. Based on studies in Chenopodium rubrum, tomato (Lycopersicon esculentum) and tobacco (Nicotiana tabacum), the regulation of extracellular invertase and its function in assimilate partitioning, defence reactions and sugar signal transduction pathways are discussed.

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Time to exhaustion at VO2max and lactate steady state velocity in sub elite long-distance runners

Archives Internationales de Physiologie de Biochimie et de Biophysique ◽

10.3109/13813459409007541 ◽

1994 ◽

Vol 102 (3) ◽

pp. 215-219 ◽

Cited By ~ 11

Author(s):

V. Billat ◽

O. Bernard ◽

J. Pinoteau ◽

B. Petit ◽

J. P. Koralsztein

Keyword(s):

Steady State ◽

Time To Exhaustion ◽

Distance Runners ◽

Long Distance

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Static Liquefaction Capacity of Saturated Undisturbed Loess in South Jingyang Platform

Water ◽

10.3390/w12082298 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2298 ◽

Cited By ~ 1

Author(s):

Rui-Xin Yan ◽

Jian-Bing Peng ◽

Jin-Yuan Zhang ◽

Shao-kai Wang

Keyword(s):

Steady State ◽

Strain Softening ◽

Shaanxi Province ◽

Triaxial Tests ◽

Pore Throat ◽

Long Distance ◽

Particle Rearrangement ◽

Static Liquefaction ◽

Small Pore ◽

Loess Landslides

According to a previous geological investigation, high-speed and long-distance loess landslides in the South Jingyang platform in Shaanxi Province are closely related to the static liquefaction of loess. Considering the typical loess landslides in this area, isotropic consolidated undrained (ICU) triaxial tests and scanning electron microscopy analyses were conducted in this study. The main conclusions are as follows: (1) The stress-strain curves indicate strong strain softening under different confining pressures. The pore water pressure increases significantly and then remains at a high level; (2) The liquefaction potential index (LPI) shows an increasing trend followed by stabilization; the larger the LPI is, the smaller the state parameter (Ψ) is. The steady-state points of the loess are in the instability region; however, the steady-state strength is not zero; (3) Based on the ICU test results, the average pore diameter decreases; the shape ratio remains essentially unchanged; and the fractal dimension and roundness show different trends. The proportions of the macropore and mesopore decrease; that of the small pore increases slightly; and that of the micropore increases significantly; (4) The compression deformation of the highly spaced pores causes rapid strain hardening. A rapid strain softening results from the pore throat blockage at the beginning of particle rearrangement and reorganization. A stable strain softening is related to the agglomeration blocking of the reconstructed pore throat in the gradually stable stage of particle rearrangement and reorganization.

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On the fine structure of sieve tubes and the physiology of assimilate transport in Alaria marginata

Canadian Journal of Botany ◽

10.1139/b75-104 ◽

1975 ◽

Vol 53 (9) ◽

pp. 861-876 ◽

Cited By ~ 41

Author(s):

Klaus Schmitz ◽

L. M. Srivastava

Keyword(s):

Fine Structure ◽

Inorganic Ions ◽

Sieve Tube ◽

Assimilate Transport ◽

Cell Organelles ◽

Long Distance ◽

Double Labeling ◽

Sieve Elements ◽

Long Distance Transport ◽

Alaria Marginata

Alaria marginata Postels and Ruprecht has a sieve tube system which extends through the lamina, especially the midrib, and through the stipe. The sieve elements originate from the innermost cortex cells and are nucleate, highly vacuolated cells that contain the usual cell organelles and membrane systems. The plastids and mitochondria show some special features in their morphology and fine structure. P protein is absent. Sieve pores, 0.11–0.3 μm in diameter, occur in cross walls between two sieve elements. They are lined by plasmalemma, and the cytoplasms of the two cells are interconnected through them. Long-distance transport of photo-assimilate follows the source–sink relationship; but its normal basipetal direction can be reversed by creating "artificial" sinks. Translocation velocity is in the range of 25 to 40 cm/h. The translocate consists mainly of mannitol and free amino acids, which were analyzed qualitatively and quantitatively. Double-labeling experiments with 32P and 14C indicate that inorganic ions are not translocated together with the 14C-labeled photoassimilates and probably move only by diffusion.

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Steady-state and transient stability of 500 kV long-distance AC transmission lines with magnetically controlled shunt reactors

2005 IEEE Russia Power Tech ◽

10.1109/ptc.2005.4524464 ◽

2005 ◽

Cited By ~ 17

Author(s):

Andrey N. Belyaev ◽

Serguei V. Smolovik

Keyword(s):

Steady State ◽

Transmission Lines ◽

Transient Stability ◽

Long Distance ◽

Ac Transmission ◽

Shunt Reactors

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Insulation Performance of Sandwich Pipe

Volume 5: Pipelines, Risers, and Subsea Systems ◽

10.1115/omae2018-77180 ◽

2018 ◽

Author(s):

Jiankun Yang ◽

Segen F. Estefen ◽

Marcelo Igor Lourenço Souza ◽

Yuxi Wang ◽

Cheng Hong

Keyword(s):

Steady State ◽

Comprehensive Evaluation ◽

Flow Assurance ◽

Insulation Material ◽

Flexible Pipe ◽

Long Distance ◽

Severe Condition ◽

Promising Alternative ◽

Offshore Oil Industry ◽

Insulation Performance

As the tendency of the offshore oil industry is going deeper and further, the subsea pipeline is exposed under tougher condition combining lower temperature with higher hydrostatic pressure. The severe condition creates a challenge towards flow assurance, which often results in a high cost solution. Reducing the cost while providing a qualified insulation performance is of great significance to deepwater development. For ultra-deepwater beyond 1500m, single-wall pipe usually fails to meet the flow assurance requirements or requires a huge amount of insulation material. Pipe-in-pipe configuration can provide a good insulation performance but comes with a high cost associated. Sandwich pipe is a new concept composed of two concentric steel pipes separated by a cementitious composite annulus that provides a combination of high structural strength with thermal insulation. It is reported to be a promising alternative for both flexible and rigid conventional pipes in applications for long distance pipelines. In order to further investigate its feasibility in deep waters, a subsea production system with depth at 2200m was used as a case study for a comprehensive evaluation of insulation performance of the sandwich pipe, including both steady-state and shut-in working conditions. For a comparative study, scenarios using single-wall pipe (SW), pipe-in-pipe (PIP) and flexible pipe (FP) were also considered separately. The results showed that (i) sandwich-pipe performs better in steady-state but worse in between shut-in and the restart period (ii) sandwich-pipe with larger diameter performs better than it with smaller diameter. The reasons for the sandwich pipe behavior were discussed and suggestions to improve the performance are presented.

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