Auswahl der wissenschaftlichen Literatur zum Thema „Gravitational Pump“

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Zeitschriftenartikel zum Thema "Gravitational Pump"

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Uhl, Jean-François, und Claude Gillot. „Anatomy of the veno-muscular pumps of the lower limb“. Phlebology: The Journal of Venous Disease 30, Nr. 3 (10.01.2014): 180–93. http://dx.doi.org/10.1177/0268355513517686.

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Objective To study the anatomy of the veno-muscular pumps of the lower limb, particularly the calf pump, the most powerful of the lower limb, and to confirm its crucial importance in venous return. Methods In all, 400 cadaveric limbs were injected with green Neoprene latex followed by an anatomical dissection. Results The foot pump is the starter of the venous return. The calf pump can be divided into two anatomical parts: the leg pump located in the veins of the soleus muscle and the popliteal pump ending in the popliteal vein with the unique above-knee collector of the medial gastrocnemial veins. At the leg level, the lateral veins of the soleus are the bigger ones. They drain vertically into the fibular veins. The medial veins of the soleus, smaller, join the posterior tibial veins horizontally. At the popliteal level, medial gastrocnemial veins are the largest veins, which end uniquely as a large collector into the popliteal vein above the knee joint. This explains the power of the gastrocnemial pump: during walking, the high speed of the blood ejection during each muscular systole acts like a nozzle creating a powerful jet into the popliteal vein. This also explains the aspiration (Venturi) effect on the deep veins below. Finally, the thigh pump of the semimembranosus muscles pushes the blood of the deep femoral vein together with the quadriceps veins into the common femoral vein. Conclusion The veno-muscular pumps of the lower limb create a chain of events by their successive activation during walking. They play the role of a peripheral heart, which combined with venous valves serve to avoid gravitational reflux during muscular diastole. A stiffness of the ankle or/and the dispersion of the collectors inside the gastrocnemius could impair this powerful pump and so worsen venous return, causing development of severe chronic venous insufficiency.
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Wang, Zaiyuan, Jiehao Wang, Fan Li, Yuhang Li, Long Tian und Qiang Liu. „Yb-Doped All-Fiber Amplifier with Low-Intensity Noise in mHz Range Oriented to Space-Borne Gravitational Wave Detection“. Applied Sciences 13, Nr. 10 (22.05.2023): 6338. http://dx.doi.org/10.3390/app13106338.

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We present a low-intensity noise single-frequency Yb-doped all-fiber amplifier oriented to space-borne gravitational wave detection. Relative intensity noise (RIN) below −70 dBc/Hz @ 1 mHz~1 Hz was achieved by virtue of feedback-loop-based intensity noise suppression. Based on systematic noise analysis and experimental investigation, we found that the pump noise and temperature-dependent noise of the fiber splitter and the photodetector contributed mainly to the RIN of the fiber amplifier. Therefore, we carefully designed a feedback-loop-based Yb-doped all-fiber amplifier, and finely stabilized the temperature of the pump diode, fiber splitters, and photodetectors. Consequently, the RIN can be suppressed down to −72.5 dBc/Hz around 1 mHz. This low-intensity all-fiber Yb-doped amplifier can be used for space-borne gravitational-wave detection.
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Jun Lu, Yunqing Fan, Jingna Song, Huayu Tang und Chuck Yu. „Application of Hydroturbine Pump in Water Source Heat Pump Drainage Gravitational Potential Energy Recovery System“. Indoor and Built Environment 19, Nr. 5 (20.08.2010): 546–54. http://dx.doi.org/10.1177/1420326x10378808.

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Ren, Haoling, Shiyi Wu, Tianliang Lin, Yonghua Zhang, Cheng Miao und Zhongshen Li. „Energy Saving Characteristics of a Winch System Driven by a Four-Quadrant Hydraulic Pump“. Machines 10, Nr. 12 (28.11.2022): 1126. http://dx.doi.org/10.3390/machines10121126.

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In this study, an integrated system of winch driving and potential energy recovery using a four-quadrant pump was proposed, aimed at the large amount of recoverable gravitational potential energy in a winch system. The proposed system changed the original open system into a closed-structure part, using a four-quadrant pump to drive the winch, and an open-structure part, using an open hydraulic pump to balance torque. The closed-structure and open-structure parts were coaxial, and connected with the engine through the transfer case, which was able to make full use of the four-quadrant pump characteristics. It was able to achieve flow regeneration when the weight was lowered, and to achieve direct use of gravitational potential energy. The AMESim model of the original and proposed systems was further established according to a working characteristics analysis of the energy consumption of the winch-driving system. The simulation results verified that the proposed system kept good controllability while recovering potential energy. An experimental prototype was built; the test results showed that, compared with the original winch system, the proposed system increased lifting speed and reduced fuel consumption significantly. Additionally, diesel consumption was reduced by 87% in the descending process.
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Davis, Michael J., Joshua P. Scallan, John H. Wolpers, Mariappan Muthuchamy, Anatoliy A. Gashev und David C. Zawieja. „Intrinsic increase in lymphangion muscle contractility in response to elevated afterload“. American Journal of Physiology-Heart and Circulatory Physiology 303, Nr. 7 (01.10.2012): H795—H808. http://dx.doi.org/10.1152/ajpheart.01097.2011.

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Collecting lymphatic vessels share functional and biochemical characteristics with cardiac muscle; thus, we hypothesized that the lymphatic vessel pump would exhibit behavior analogous to homeometric regulation of the cardiac pump in its adaptation to elevated afterload, i.e., an increase in contractility. Single lymphangions containing two valves were isolated from the rat mesenteric microcirculation, cannulated, and pressurized for in vitro study. Pressures at either end of the lymphangion [input pressure (Pin), preload; output pressure (Pout), afterload] were set by a servo controller. Intralymphangion pressure (PL) was measured using a servo-null micropipette while internal diameter and valve positions were monitored using video methods. The responses to step- and ramp-wise increases in Pout (at low, constant Pin) were determined. PL and diameter data recorded during single contraction cycles were used to generate pressure-volume (P-V) relationships for the subsequent analysis of lymphangion pump behavior. Ramp-wise Pout elevation led to progressive vessel constriction, a rise in end-systolic diameter, and an increase in contraction frequency. Step-wise Pout elevation produced initial vessel distention followed by time-dependent declines in end-systolic and end-diastolic diameters. Significantly, a 30% leftward shift in the end-systolic P-V relationship accompanied an 84% increase in dP/d t after a step increase in Pout, consistent with an increase in contractility. Calculations of stroke work from the P-V loop area revealed that robust pumps produced net positive work to expel fluid throughout the entire afterload range, whereas weaker pumps exhibited progressively more negative work as gradual afterload elevation led to pump failure. We conclude that lymphatic muscle adapts to output pressure elevation with an intrinsic increase in contractility and that this compensatory mechanism facilitates the maintenance of lymph pump output in the face of edemagenic and/or gravitational loads.
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Mubarokhah, Lailatul, und Wijanarka Wijanarka. „Uji bakteriologis air di PDAM GT Kabupaten Magelang dengan metode MPN Quanty-Tray“. JURNAL BIOLOGI PAPUA 11, Nr. 1 (29.05.2019): 18–23. http://dx.doi.org/10.31957/jbp.747.

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Water is the main need for life. The bacteriological requirements for clean water are the presence or absence of Coliform bacteria and E. coli in water. The purpose of this study was to determine the quality of water from gravity springs and pump springs as a source of water in Magelang Regency PDAM GT and Magelang Regency community. This study was to finding out the bacteriological test of water in Magelang Regency PGT. This study was to know bacteriological water testing techniques using the MPN Quanti-method Tray in Magelang Regency PGT. The method used in this study is the Quanty-Tray Most Probable Number (MPN) method. The sample of this study were two gravitational springs namely Sample A and Sample B and two pumping springs namely Sample C and Sample D. The results of MPN calculations from the four springs did not meet the requirements of clean water ready to be distributed to the community because Coliform in the spring gravity water and pumps and found E. coli in the pump spring water. Key words: coliform, MPN quanty-tray, bacteriological requirement.
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Chechin, L. M. „Dark matter halo as the dispersional gravitational lens“. Modern Physics Letters A 29, Nr. 37 (04.12.2014): 1440002. http://dx.doi.org/10.1142/s0217732314400021.

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Based on the time-variability of the dark matter (DM) parameter of state (PoS) type of [Formula: see text], the conception of dispersional gravitational lens (DGL) was proposed. The dependency of refractive index of DM halo on its own global oscillations was found. It was shown that DM does not oscillate with optical or ultraviolet and X-ray diapasons, but it may oscillate with essentially low frequency — ϖ DM ≥10-15 Hz . Hence, it is possible to talk about the ultra weak DM oscillations, and the very cold dark matter (VCDM) particles whose masses are larger than m VCDM ≥10-42 eV . It was marked briefly that DM global oscillations will gradually pump with elastic energy the galaxy's baryonic matter. Hence, they may be the real reason of its subsequent fragmentation and the inner galaxy structure formation.
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Kontos, Antonios, und Rainer Weiss. „Photon emission spectrum of ion pumps“. Review of Scientific Instruments 94, Nr. 3 (01.03.2023): 034503. http://dx.doi.org/10.1063/5.0138917.

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As the sensitivity of gravitational-wave detectors increases, new sources of noise appear. A potential source of noise may arise from charge accumulating on the mirrors of the experiment, the origin of which can be related to UV photons from the surroundings. In order to test one hypothesis, we measured the photon emission spectrum from a type of ion pump that is used in the experiment, an Agilent VacIon Plus 2500 l/s. We found that there is significant emission of UV photons above 5 eV, capable of knocking electrons off mirrors or surrounding surfaces and charging them. Photon emission measurements were taken as a function of gas pressure, ion-pump voltage setting, and type of pumped gas. The overall emission and shape of the measured photon spectrum are consistent with bremsstrahlung as the mechanism for the production of the photons.
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Makarieva, A. M., und V. G. Gorshkov. „Biotic pump of atmospheric moisture as driver of the hydrological cycle on land“. Hydrology and Earth System Sciences Discussions 3, Nr. 4 (30.08.2006): 2621–73. http://dx.doi.org/10.5194/hessd-3-2621-2006.

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Abstract. In this paper the basic geophysical and ecological principles are jointly analyzed that allow the landmasses of Earth to remain moistened sufficiently for terrestrial life to be possible. 1. Under gravity, land inevitably loses water to the ocean. To keep land moistened, the gravitational water runoff must be continuously compensated by the atmospheric ocean-to-land moisture transport. Using data for five terrestrial transects of the International Geosphere Biosphere Program we show that the mean distance to which the passive geophysical air fluxes can transport moisture over non-forested areas, does not exceed several hundred kilometers; precipitation decreases exponentially with distance from the ocean. 2. In contrast, precipitation over extensive natural forests does not depend on the distance from the ocean along several thousand kilometers, as illustrated for the Amazon and Yenisey river basins and Equatorial Africa. This points to the existence of an active biotic pump transporting atmospheric moisture inland from the ocean. 3. Physical principles of the biotic moisture pump are investigated based on the previously unstudied properties of atmospheric water vapor, which can be either in or out of hydrostatic equilibrium depending on the lapse rate of air temperature. A novel physical principle is formulated according to which the low-level air moves from areas with weak evaporation to areas with more intensive evaporation. Due to the high leaf area index, natural forests maintain high transpiration fluxes, which support the ascending air motion over the forest and "suck in" moist air from the ocean, which is the essence of the biotic pump of atmospheric moisture. In the result, the gravitational runoff water losses from the optimally moistened forest soil can be fully compensated by the biotically enhanced precipitation at any distance from the ocean. 4. It is discussed how a continent-scale biotic water pump mechanism could be produced by natural selection acting on individual trees. 5. Replacement of the natural forest cover by a low leaf index vegetation leads to an up to tenfold reduction in mean continental precipitation and runoff, in contrast to the previously available estimates made without accounting for the biotic moisture pump. The analyzed body of evidence testifies that the long-term stability of an intense terrestrial water cycle is unachievable without the recovery of natural, self-sustaining forests on continent-wide areas.
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Makarieva, A. M., und V. G. Gorshkov. „Biotic pump of atmospheric moisture as driver of the hydrological cycle on land“. Hydrology and Earth System Sciences 11, Nr. 2 (27.03.2007): 1013–33. http://dx.doi.org/10.5194/hess-11-1013-2007.

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Abstract. In this paper the basic geophysical and ecological principles are jointly analyzed that allow the landmasses of Earth to remain moistened sufficiently for terrestrial life to be possible. 1. Under gravity, land inevitably loses water to the ocean. To keep land moistened, the gravitational water runoff must be continuously compensated by the atmospheric ocean-to-land moisture transport. Using data for five terrestrial transects of the International Geosphere Biosphere Program we show that the mean distance to which air fluxes can transport moisture over non-forested areas, does not exceed several hundred kilometers; precipitation decreases exponentially with distance from the ocean. 2. In contrast, precipitation over extensive natural forests does not depend on the distance from the ocean along several thousand kilometers, as illustrated for the Amazon and Yenisey river basins and Equatorial Africa. This points to the existence of an active biotic pump transporting atmospheric moisture inland from the ocean. 3. Physical principles of the biotic moisture pump are investigated based on the previously unstudied properties of atmospheric water vapor, which can be either in or out of aerostatic equilibrium depending on the lapse rate of air temperature. A novel physical principle is formulated according to which the low-level air moves from areas with weak evaporation to areas with more intensive evaporation. Due to the high leaf area index, natural forests maintain high evaporation fluxes, which support the ascending air motion over the forest and "suck in" moist air from the ocean, which is the essence of the biotic pump of atmospheric moisture. In the result, the gravitational runoff water losses from the optimally moistened forest soil can be fully compensated by the biotically enhanced precipitation at any distance from the ocean. 4. It is discussed how a continent-scale biotic water pump mechanism could be produced by natural selection acting on individual trees. 5. Replacement of the natural forest cover by a low leaf index vegetation leads to an up to tenfold reduction in the mean continental precipitation and runoff, in contrast to the previously available estimates made without accounting for the biotic moisture pump. The analyzed body of evidence testifies that the long-term stability of an intense terrestrial water cycle is unachievable without the recovery of natural, self-sustaining forests on continent-wide areas.
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Dissertationen zum Thema "Gravitational Pump"

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Steinke, Michael [Verfasser]. „Fiber amplifiers at 1.5 [my]m for gravitational wave detectors : power scaling, gain dynamics, and pump sources / Michael Steinke“. Hannover : Technische Informationsbibliothek (TIB), 2015. http://d-nb.info/1095506102/34.

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Terrats, Louis. „Le flux de carbone particulaire et le lien avec la communauté phytoplanctonique : une approche par flotteurs-profileurs biogéochimiques“. Electronic Thesis or Diss., Sorbonne université, 2022. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2022SORUS550.pdf.

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L'Océan est un acteur majeur du climat en échangeant avec l'atmosphère de grandes quantités de carbone. Le carbone atmosphérique est fixé à la surface de l’océan par le phytoplancton qui le transforme en carbone biogène, dont une partie est transportée vers l’océan profond par des mécanismes physiques et biologiques; il s’agit de la Pompe Biologique de Carbone (BCP). Une infime partie de ce carbone biogène atteindra des profondeurs suffisantes pour être séquestré durant plusieurs siècles avant qu'il ne retourne dans l'atmosphère, régulant les concentrations atmosphériques de CO2. Aujourd'hui, nous en savons assez sur la BCP pour reconnaitre son importance dans le climat, mais nos connaissances sur son fonctionnement sont limitées en raison d’un échantillonnage insuffisant des flux de carbone biogène. Dans ce travail de thèse, nous avons utilisé les flotteurs BioGéoChimique-Argo, plateformes d’observations conçues pour résoudre le problème du sous-échantillonnage, afin d’explorer un mécanisme majeur de la BCP qui est la pompe gravitationnelle. La pompe gravitationnelle est le transport du carbone biogène sous la forme de particules organiques (POC) qui sédimentent de la surface vers l’océan profond. Notre étude de la pompe gravitationnelle se divise en trois axes. Le premier axe consiste au développement d’une méthode pour détecter les floraisons de coccolithophoridés, groupe phytoplanctonique majeur qui a potentiellement un contrôle important sur le transport du POC en profondeur. Le deuxième axe est centré sur la variabilité saisonnière et régionale des flux de POC dans l’Océan Austral, qui est une zone sous-échantillonnée mais dans laquelle plusieurs flotteurs ont été déployés avec une trappe optique à sédiments (OST). Seuls une dizaine de flotteurs sont équipés d’OST, ce qui est faible en comparaison avec l’ensemble de la flotte BGC-Argo (i.e. plusieurs centaines de flotteurs). C’est pourquoi nous avons développé, dans le troisième axe, une méthode pour estimer le flux de POC avec les capteurs standards du programme BGC-Argo. Cette méthode a ensuite été appliquée à une centaine de flotteurs pour décrire la variabilité saisonnière du flux de POC dans de nombreuses régions océaniques. Dans ce travail de thèse, nous mettons également en évidence le lien entre la variabilité des flux et la nature des particules en surface. Par exemple, nous avons calculé des relations entre la composition de la communauté phytoplanctonique et les flux de POC à 1000m. En utilisant ces relations, nous avons ensuite utilisé les observations satellites pour extrapoler les flux de POC à de larges échelles spatiales, comme à l’ensemble de l’Océan Austral et de l’océan global
The ocean plays a key role in the climate by exchanging large quantities of carbon with the atmosphere. Atmospheric carbon is fixed at the ocean surface by phytoplankton that transforms it into biogenic carbon, part of which is transported to the deep ocean by physical and biological mechanisms; this is the Biological Carbon Pump (BCP). A tiny fraction of this biogenic carbon reaches sufficient depths to be sequestered for several centuries before it returns to the atmosphere, thus regulating concentrations of atmospheric CO2. Today, we know enough about the BCP to recognize its importance in climate, but our knowledge of its functioning is limited due to insufficient sampling of biogenic carbon fluxes. Here, we used BioGeoChimical-Argo floats, observational platforms designed to solve the undersampling problem, to explore a major mechanism of the BCP called the gravitational pump. The gravitational pump is the transport of biogenic carbon in the form of organic particles (POC) that sink from the surface into the deep ocean. Our study of the gravitational pump is divided into three axes. The first axis consisted of developing a method to detect blooms of coccolithophores, a major phytoplankton group that potentially has an important control on the transport of POC at depth. The second axis focused on the seasonal and regional variability of POC fluxes in the Southern Ocean, an undersampled area in which several floats have been deployed with an optical sediment trap (OST). Only ten floats were equipped with an OST, which is low compared to the whole BGC-Argo fleet (i.e. several hundred floats). Therefore, in the third axis, we developed a method to estimate the POC flux with the standard sensors of BGC-Argo floats. This method was then applied to hundreds of floats to describe the seasonal variability of the POC flux in many regions. In this study, we also highlighted the link between the POC flux and the nature of surface particles. For example, we calculated relationships between phytoplankton community composition and POC flux at 1000m. Using these relationships, we then used satellite observations to extrapolate POC flux to large spatial scales, such as the entire Southern Ocean and the global ocean
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Benešová, Irena. „Čistírny odpadních vod pro obce s gravitačním přítokem“. Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240347.

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Diploma thesis is aimed on description of wastewater treatment plant with gravitational inflow. Focus is on WWTP in the Czech Republic, particularly in the South Moravia region - in this aspect the thesis presents relevant statistics like the number of WWTP per region and the total, capacity of WWTP per region and their substance load on inflow /outflow. The recherche is also limited according to the core subject of theoretical part, which is technology of small WWTP in the category up to 2000 equivalent habitants. The experimental part presents comparsion of particular wastewater treatment plant of this category in the South Moravia region: one with gravitational inflow and one with inflow pump station. The examined wastewater treatment plant are compared according to substance load, hydraulic load and technology. Thesis is concluded with a review of the different operation parameters of the both types of WWTP.
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Buchteile zum Thema "Gravitational Pump"

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Rocha Dias, Juvenal, und Eliane Aparecida Faria Amaral Fadigas. „A Reverse Osmosis and Electrodialysis System Simultaneously Powered by Gravitational Potential Energy“. In Electrodialysis. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.91135.

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This chapter proposes an alternative system for conventional reverse osmosis (RO) and electrodialysis (ED) desalination plants by incorporating the use of gravitational potential energy (GPE). The proposed system is devised with two subsystems, the RO module followed by the ED module, both simultaneously powered by GPE. This kind of energy is obtained by storing the brackish water to be desalinated. The system’s primary source of energy is wind. Windmills harness the wind energy to pump water to a reservoir located at a certain height (<20 m). The stored water has the GPE that will make a special plunger pump work. The piston of this special plunger pump is designed so that high pressure (about 15 bar) can be achieved in a different way from conventional RO plants. In the alternative system, here proposed, to pump water to the RO membranes, the special pistons go downward due to their own weight and are lifted, through a system of pulleys, with a counterweight filled with water obtained from the reservoir. The technical viability of the alternatives was theoretically proven by deductions based on physics and mathematics and with a special plunger pump prototype that worked successfully.
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„Simulation researches of pump-gravitational storage reservoir and its application in sewage systems“. In Underground Infrastructure of Urban Areas, 87–94. CRC Press, 2008. http://dx.doi.org/10.1201/b10996-14.

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„6. Appendix II (PUP 4th edition, 1953): Generalization of Gravitation Theory“. In The Formative Years of Relativity, 293–325. Princeton University Press, 2018. http://dx.doi.org/10.1515/9781400888689-021.

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Konferenzberichte zum Thema "Gravitational Pump"

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Salah, Ahmed, Ahmed Sabaa, A. Samir Abd Elhaleem, Ahmed Medhat, Ahmed Diaa und Osama Abu-hozifa. „ESP Design Improvements Associated with Downhole Slotted Gravitational Filter and Downhole Chemical Treatment Prolong ESPs Run Life in Western Desert of Egypt: Case Study“. In ADIPEC. SPE, 2023. http://dx.doi.org/10.2118/216428-ms.

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Abstract Electrical submersible pumps (ESPs) have become the most efficient and reliable artificial-lift method worldwide. One of the most common causes of premature failure in ESP systems is erosion or clogging from sand and solids in the reservoir fluids. These solids generate wear in pump stages, reduce its lifting efficiency and increase frequency of well interventions. Consequently, these ESP failures require reliable solutions to enhance the performance and prolong the run life of the ESP system. In subject field inside the Western Desert of Egypt, several wells were experiencing pre-mature pump failures because of plugging, sand erosion on pump stages, and broken shafts. Five previous ESPs had been run in three offset wells, all of them had failed after average run life of 150 days. A detailed discussion with a technology provider and reference case studies come up with an integrated approach utilizing ESP Design improvements including Reliable Abrasion-Resistant Pumps and upgraded shaft material. The ESP system also incorporates a downhole slotted gravitational sand filter and continuous downhole chemical injection. The slotted gravitational Sand filter is an innovative solution to take control of downhole sand problems utilizing gravitational force and filtration process. It prevents particles 100 microns and larger in size from entering and damaging the ESP system. In SWM field, Hydrocarbon recovery is mainly from one deep reservoir characterized by a high-pressure high-temperature (HPHT) environment at depths around 16000 ft, average pressure of nearly 6400 psi, temperature reaching 310 F, and considerable amounts of CO2 and H2S. The pump was set at 10000 ft to produce 2000 BPD with wellhead pressure not less than 1000 psi. In spite of, these challenging operating conditions and high withdrawal requirements, the newly designed system was capable to maintain stable ESP performance in two offset wells for more than 14 months and still ESPs are running. This solution showed significant improvement in overall system reliability and performance. Specifically, it helped to economically produce from the wells, reduce deferred production and downtime resulting from frequent pump failures, and maximize their recoverable reserves. In addition, it increased the capability of being replicated in other wells with high sand production. This paper will provide a detailed completion design process to create a robust ESP system that fits with challenging wellbore conditions in which sand production and erosion are growing concerns. This study starts from initial installations, subsequent well interventions, equipment Dismantle Inspection and Failure Analysis (DIFA), ESP configuration enhancements, and finally reaches field application performance data in which the new completion design was successfully implemented to extend ESP run life.
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Tanaka, Takaharu. „An Investigation on Energy Transfer Mechanism Caused in Rotating Flow Passage of Turbomachinery and Practical Performance Characteristic Curve“. In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95441.

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Hydraulic energy is constructed from two different kinds hydraulic energies. One is the singled irreversible kinetic hydraulic energy that acts horizontal direction. It produces mass weight flow rate. The other is the un-kinetic reversible potential energy. Potential energy is stored on the fluid particle in the form of coupled (or twined) real and imaginary energies. Typical of real energy is potential energy, which is equivalent to pump and water turbine heads. It is caused by the real gravitational acceleration and directs vertical downward. Real potential head is balanced with the imaginary force, which is caused by the imaginary acceleration whose magnitude is equivalent to real gravitational acceleration but its acting direction is opposed to that, therefore, vertical upward. Therefore, to produce the higher real potential pump head that directs vertical downward, the imaginary centrifugal force, whose acting direction is opposed to real potential head, has to be produced and act on the fluid particle vertical upward as much by the impelling action in the rotating flow passage of centrifugal pump.
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Jo, Jong Chull, Kyung Wan Roh, Hho Jhung Kim und Kyun Tae Kim. „Prediction of Potential for the Ingression of Crude Oil Covering the Sea Water Surface Into the Sea Water Cooling System of Nuclear Power Plant“. In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-77404.

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When an incident of crude oil spill from an oil carrier occurs in the sea near the nuclear power plants, the spilled oil can be transported to the intake pit, where the NSCW (nuclear service cooling water) pumps locate, by sea current and wind drift (induced) current. The NSCW pumps take the essential service water from the sea being used as the ultimate heat sink and supply to the component cooling water heat exchangers to remove the decay heat generated from reactor. The NSCW system shall provide sufficient cooling capacity during the reactor normal operation, transients, and loss-of-coolant accidents (LOCAs). In this regard, it is very important to confirm if the cooling function of the NSCW system can be threaten due to spilled oil which may overspread the surface of sea water in the intake area. Thus, in this work, when an incident of crude oil spill occurs in the sea near a nuclear power plant using sea water as the ultimate heat sink, possibility of crude oil ingression into the component cooling water heat exchangers through the NSCW pumps has been evaluated in a conservative manner. To do this, for a flow field surrounding a NSCW pump equipped in an intake pit where a limited volume of sea water is initially contained and its surface is covered with spilled crude oil, a numerical simulation is performed using a CFD (Computational Fluid Dynamics) code. The objective of the present simulation is to find out the critical sea water level at or below which oil or air floating on the surface of sea water begins to be sucked in the pump inlet nozzle. The numerical simulation results show that in general, the oil covering the free surface of sea water in the intake can hardly flow into the pump inlet until the floating oil changes into tars which are heavier than oil as long as the sea water level does not fall below the limit value specified in the Technical Specification of each nuclear plant. It is also shown that the critical sea water level increases as the pump flowrate increases. This is physically plausible considering the effect of gravitational force.
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Bamberger, Judith Ann, und Carl W. Enderlin. „Experimental Evaluation of Dual-Opposed Jet Mixer Pump Performance for Slurry Mixing“. In ASME 2016 Fluids Engineering Division Summer Meeting collocated with the ASME 2016 Heat Transfer Summer Conference and the ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/fedsm2016-7749.

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Million-gallon double-shell tanks at Hanford are used to store transuranic, high-level, and low-level radioactive wastes. These wastes consist of a large volume of salt-laden solution covering a smaller volume of settled sludge primarily containing metal hydroxides. These wastes will be retrieved and processed into immobile waste forms suitable for permanent disposal. Retrieval is an important step in implementing these disposal scenarios. The retrieval concept evaluated is to use submerged dual-nozzle jet mixer pumps with horizontally oriented nozzles located near the tank floor that produce horizontal jets of fluid to mobilize the settled solids. The mixer pumps are oscillated through 180° about a vertical axis so the high velocity fluid jets sweep across the floor of the tank. After the solids are mobilized, the pumps will continue to operate at a reduced flow rate producing lower velocity jets sufficient to maintain the particles in a uniform suspension (concentration uniformity). Several types of waste and tank configurations exist at Hanford. The jet mixer pump systems and operating conditions required to mobilize sludge and maintain slurry uniformity will be a function of the waste type and tank configuration. The focus of this work was to conduct a 1/12-scale experiment to develop an analytical model to relate slurry uniformity to tank and mixer pump configurations, operating conditions, and sludge properties. This experimental study evaluated concentration uniformity in a 1/12-scale experiment varying the Reynolds number (Re), Froude number (Fr), and gravitational settling parameter (Gs) space. Simulant physical properties were chosen to obtain the required Re and Gs where Re and Gs were varied by adjusting the kinematic viscosity and mean particle diameter, respectively. Test conditions were achieved by scaling the jet nozzle exit velocity in a 75-in. diameter tank using a mock-up of a centrally located dual-opposed jet mixer pump located just above the tank floor. Concentration measurements at sampling locations throughout the tank were used to assess the degree of uniformity achieved during each test. Concentration data was obtained using a real time in-situ ultrasonic attenuation probe and post-test analysis of discrete batch samples. The undissolved solids concentration at these locations was analyzed to determine whether the tank contents were uniform (≤ ±10% variation about mean) or nonuniform (> ±10% variation about mean) in concentration. Concentration inhomogeneity was modeled as a function of dimensionless parameters. The parameters that best describe the maximum solids volume fraction that can be suspended were found to be 1) the Fr based on nozzle average discharge velocity and tank contents level and 2) the dimensionless particle size based on nozzle diameter. The dependence on the jet Re does not appear to be statistically significant.
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Osadchiev, Alexander, Alexander Osadchiev, Peter Zavialov, Peter Zavialov, Vadim Pelevin und Vadim Pelevin. „METHOD FOR QUANTIFYING ADVECTION, TURBULENT MIXING, AND GRAVITATIONAL SETTLING OF RIVER-BORNE SUSPENDED SEDIMENTS IN COASTAL AREAS FROM THERMOHALINE AND OPTICAL MEASUREMENTS“. In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b94a309e5c6.22106638.

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This work presents an original method for quantifying advection and turbulent mixing of river-borne suspended sediments. The main idea of the method consists in joint analysis of surface distributions of salinity and sediment concentration in coastal areas influenced by river discharge. Basing on the Lagrangian approach we represent a river plume as a set of individual water particles, which inflow from a river mouth, mix with ambient sea water during their motion within a river plume and finally dissipate. Surface salinity and sediment concentration of a particle provides information about its turbulent mixing with undelaying ambient sea waters and gravitational settling of its sediments respectively during the period from its origin in the river estuary till the moment of measurement. Using these integrated Lagrangian characteristics calculated for the whole study area we reconstruct advection streamlines within the river plume and ratio between turbulent mixing and gravitational settling of river-borne suspended sediments. This method was applied to coastal areas situated in the north-eastern part of the Black Sea and the western part of the Philippine Sea. High resolution thermohaline and sediment concentration data were collected using a pump-through system equipped by a CTD instrument and a turbidity sensor.
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Osadchiev, Alexander, Alexander Osadchiev, Peter Zavialov, Peter Zavialov, Vadim Pelevin und Vadim Pelevin. „METHOD FOR QUANTIFYING ADVECTION, TURBULENT MIXING, AND GRAVITATIONAL SETTLING OF RIVER-BORNE SUSPENDED SEDIMENTS IN COASTAL AREAS FROM THERMOHALINE AND OPTICAL MEASUREMENTS“. In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b431548658b.

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This work presents an original method for quantifying advection and turbulent mixing of river-borne suspended sediments. The main idea of the method consists in joint analysis of surface distributions of salinity and sediment concentration in coastal areas influenced by river discharge. Basing on the Lagrangian approach we represent a river plume as a set of individual water particles, which inflow from a river mouth, mix with ambient sea water during their motion within a river plume and finally dissipate. Surface salinity and sediment concentration of a particle provides information about its turbulent mixing with undelaying ambient sea waters and gravitational settling of its sediments respectively during the period from its origin in the river estuary till the moment of measurement. Using these integrated Lagrangian characteristics calculated for the whole study area we reconstruct advection streamlines within the river plume and ratio between turbulent mixing and gravitational settling of river-borne suspended sediments. This method was applied to coastal areas situated in the north-eastern part of the Black Sea and the western part of the Philippine Sea. High resolution thermohaline and sediment concentration data were collected using a pump-through system equipped by a CTD instrument and a turbidity sensor.
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Wang, Xiangyu, Hongjuan Zhang, Xiaogang Zhang und Long Quan. „Design and Efficiency Analysis of Closed Loop Pump Controlled Circuit Hydraulic Lifting System of Wheel Loaders Based on Gravity Self-Balancing Hydraulic Cylinder“. In ASME/BATH 2021 Symposium on Fluid Power and Motion Control. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/fpmc2021-68861.

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Abstract In the hydraulic lifting systems of wheel loaders, the valve controlled systems are used to drive the hydraulic cylinder to complete frequent lifting and falling operations. The gravitational potential energy of the lifting system, accumulated in the lifting process, is converted into heat energy through the throttling port of the valve during the falling processes, which results in significant throttling loss and severe system overheating. To solve the problems, a potential energy regeneration and utilization system is proposed, where the closed loop pump controlled circuit based on the gravity self-balancing hydraulic cylinder is adopted to eliminate throttling loss, and the gravity self-balancing chamber of the cylinder is directly connected with accumulator to recycle gravity potential energy. In the research, the structure and working principle of the proposed hydraulic system is analyzed first, then the co-simulation model and the test prototype are established to investigate the working and energy characteristics of the proposed system. Test results indicate that, compared with the traditional valve controlled hydraulic system, 58.9% energy consumption reduction can be expected for the hydraulic pump by adopting the proposed system under the same working condition.
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Gluscevic, Andreja Ante. „Backpressure Reduction on Beam Pumping Wells by Flowline Gas Purging“. In SPE Middle East Artificial Lift Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/206957-ms.

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Abstract Tatweer Petroleum has faced challenges in production caused by high backpressure against beam pump wells that are producing from low pressure and weak inflow reservoirs in the Bahrain Field. To overcome these challenges, different projects have been conducted, depending on the main source of backpressure. Therefore, this paper will describe the significant positive impact on production and pump efficiency by handling backpressure issues on wells and/or group of wells with long oil flow-lines. Beam pumping is a method of oil production that has been used for more than 100 years in a vast variety of oil fields due to its simple operations. Its usage increases in pressure-depleted reservoirs due to the pumps’ ability to maximize drawdown; hence production. Nevertheless, even after 100 years, production engineering challenges persist in dealing with issues such as backpressure. Complexity is also added when operating beam pumps in low reservoir-pressure, or highly-fractured and tight carbonate reservoirs. It was identified that in long flow lines subsequent gas and liquid slugs are formed due to slow flow, low pressure and gravitational segregation. The slug formation is enhanced with variable elevation of different flow-line sections. In order to move slugs through the flow lines, more energy is required, thus line pressure increases. Movement of fluids according to the project is enabled by high pressure gas injected in the line on cyclic basis in very short time. This way wells are not under high pressure during injection and on the other hand flow line is purged and all slugs are removed so most of the time backpressure is low. The main objective of the project was achieved by adding gas injection at the satellite manifold, consisting of multiple wells. This can also be achieved by adding well producing with intermittent gas lift, stop-cock or plunger lift. Introducing high-pressure gas intermittently, downstream the wellhead or remote satellite manifold would purge all the slugs and instantly drop the line pressure to the minimum. Implementing this project oil production was increased twice and made more stable. Regarding wells equipped with Beam Pumps, seldom was challenged problem with backpressure of the facilities or flow assurance, assuming by default that pump would overcome any of possible issues. This paper discusses and proposes solution of overcoming backpressure from facilities as a key factor to produce optimally.
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Mench, M. M., Z. H. Wang, K. Bhatia und C. Y. Wang. „Design of a Micro Direct Methanol Fuel Cell (μDMFC)“. In ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/htd-24272.

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Abstract Recently, there has been increased interest in the development of a small-sized direct methanol fuel cell (DMFC) for low-power applications. In this paper, the design of a self-activated DMFC stack is presented. Gravitational and capillary forces feed the anode side liquid methanol solution. On the cathode side, air is supplied by thermal and solutal buoyancy forces. Based upon experimental results for a larger test cell, and calculated flow velocities for the small-cell design, the fuel and oxidizer supply rates should be adequate for acceptable performance. The entire DMFC is therefore a pump-less operation and self-activated by electrochemical reactions. At 1 cm3 total volume, the DMFC is expected to provide a power density around 1 W/cm3, with a range of output of 10V, 0.1A to 1 V, 1A depending on the arrangement of individual cell connections.
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10

Enderlin, Carl W., Judith Ann Bamberger und Michael J. Minette. „Evaluating Transfer and Pumping of Slurries From Pulsed Jet Mixed Vessels“. In ASME 2020 Fluids Engineering Division Summer Meeting collocated with the ASME 2020 Heat Transfer Summer Conference and the ASME 2020 18th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/fedsm2020-20390.

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Abstract Due to gravity, solids in slurries will settle if density differences between the solids and liquid are positive (i.e., particle has a negative buoyant force) unless rheological properties and flow conditions are adequate to overcome the gravitational effects. The rate of settling depends on the force balance of the particle, which includes the surface forces associated with fluid rheology. Given the same fluid and solid properties, the larger and more dense particles tend to settle faster. When pumping slurry into a vessel at concentrations precluding hindered settling with insufficient mixing, particle and density distributions can result in preferential settling, creating stratification in the solids concentration within the vessel. For vessels with transfer line inlets located in the lower portion of the tank, the stratified solids concentration may be detrimental to the transfer system performance. Elevated concentrations of solids in the slurry entrained at the inlet to the transfer line can result in the effective viscosity or slurry bulk density exceeding the design limits of the pump. These conditions could result in plugging of the transfer line or onset of cavitation of the pumps because of excessive pressure drop. These conditions can be exacerbated with periodic inlet conditions existing at the transfer line inlet. Periodic conditions can result when vessel mixing is intermittent such as with pulsed jet mixers (PJM). The transfer line inlet conditions are impacted by the periodic nature of the PJM operations with respect to suspension of solids and their transport to the inlet of the transfer line. A scaling approach is presented, and corresponding test requirements are developed for assessing the prevention of plugging the pipeline. Line plugging mechanisms are addressed that exclude plugging due to steady-state high-density slurry entering the transfer line and reducing the net positive suction head available (NPSHA) at the pump inlet to below that required for pump operation. Items considered include the transition to reduced relative flow velocities, such that the critical pipe velocity for solids deposition, Ucd, is not maintained, and segregation of heavy solids during the transport. The recommended requirements to prevent plugging include: • Limits for viscosity and density for entrained slurry to prevent the pressure drop in the pipeline from exceeding pump capacity. • Limits for viscosity and density for entrained slurry to prevent the net positive suction head available (NPSHA) from falling below the net positive suction head required (NPSHR) for operating the pump. • Transfer line velocity and flow rate requirements to maintain solids in suspension, while avoiding line plugging that results from deposition of solids within the transfer line. This paper describes the development of the scaling and testing requirements to verify that proposed approaches for transfer and pump out are appropriately developed for operational success within the plant operating windows.
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Berichte der Organisationen zum Thema "Gravitational Pump"

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Morkun, Volodymyr, Natalia Morkun, Andrii Pikilnyak, Serhii Semerikov, Oleksandra Serdiuk und Irina Gaponenko. The Cyber-Physical System for Increasing the Efficiency of the Iron Ore Desliming Process. CEUR Workshop Proceedings, April 2021. http://dx.doi.org/10.31812/123456789/4373.

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It is proposed to carry out the spatial effect of high-energy ultrasound dynamic effects with controlled characteristics on the solid phase particles of the ore pulp in the deslimer input product to increase the efficiency of thickening and desliming processes of iron ore beneficiation products. The above allows predicting the characteristics of particle gravitational sedimentation based on an assessment of the spatial dynamics of pulp solid- phase particles under the controlled action of high-energy ultrasound and fuzzy logical inference. The object of study is the assessment of the characteristics and the process of control the operations of thickening and deslaming of iron ore beneficiation products in the conditions of the technological line of the ore beneficiation plant. The subject of study is a cyber-physical system based on the use of high-energy ultrasound radiation pressure effects on iron-containing beneficiation products in the technological processes of thickening and desliming. The working hypothesis of the project is that there is a relationship between the physical-mechanical and chemical-mineralogical characteristics of the iron ore pulp solid- phase particles and their behavior in technological flows under the influence of controlled ultrasonic radiation, based on which the imitation modeling of the gravitational sedimentation process of the iron ore pulp solid-phase particles can be performed directly in the technological process. Also, the optimal control actions concerning the processes of thickening and desliming can be determined.
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