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Статті в журналах з теми "Sinking speed"
1
TUCKER, VANCE A. "Gliding Birds: Descending Flight of the Whitebacked Vulture, Gyps Africanus." Journal of Experimental Biology 140, no. 1 (November 1, 1988): 325–44. http://dx.doi.org/10.1242/jeb.140.1.325.
Повний текст джерелаАнотація:
The air speeds and sinking speeds of birds gliding at equilibrium fall in a performance area when these quantities are plotted against one another. Three curves bound the performance area: (i) a curve for minimum sinking speed at each air speed, (ii) a curve for maximum sinking speed at each air speed, and (iii) a curve dependent on the maximum lift coefficient of the wings. I have discussed curve i in a previous paper. This paper discusses the theory of curves ii and iii, which describe rapid descent in gliding birds. I used an optical tracking device (an ornithodolite) to measure air speeds and sinking speeds of 16 African white-backed vultures (Gyps africanus Salvadori) descending rapidly from altitudes 200–500 m above the ground. The ornithodolite measured the polar coordinates of a bird's position in space (relative to the ground) and recorded them on magnetic tape. The vultures had air speeds between 5.4 and 39.lms−1, and sinking speeds between 0.2 and 8.3ms−1. Most of the observations fell within the theoretical boundaries of the performance area. These data are consistent with a maximum lift coefficient of 2.2 for the wings of white-backed vultures.
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Rosen, M., and A. Hedenstrom. "Gliding flight in a jackdaw: a wind tunnel study." Journal of Experimental Biology 204, no. 6 (March 15, 2001): 1153–66. http://dx.doi.org/10.1242/jeb.204.6.1153.
Повний текст джерелаАнотація:
We examined the gliding flight performance of a jackdaw Corvus monedula in a wind tunnel. The jackdaw was able to glide steadily at speeds between 6 and 11 m s(−1). The bird changed its wingspan and wing area over this speed range, and we measured the so-called glide super-polar, which is the envelope of fixed-wing glide polars over a range of forward speeds and sinking speeds. The glide super-polar was an inverted U-shape with a minimum sinking speed (V(ms)) at 7.4 m s(−1) and a speed for best glide (V(bg)) at 8.3 m s(−)). At the minimum sinking speed, the associated vertical sinking speed was 0.62 m s(−1). The relationship between the ratio of lift to drag (L:D) and airspeed showed an inverted U-shape with a maximum of 12.6 at 8.5 m s(−1). Wingspan decreased linearly with speed over the whole speed range investigated. The tail was spread extensively at low and moderate speeds; at speeds between 6 and 9 m s(−1), the tail area decreased linearly with speed, and at speeds above 9 m s(−1) the tail was fully furled. Reynolds number calculated with the mean chord as the reference length ranged from 38 000 to 76 000 over the speed range 6–11 m s(−1). Comparisons of the jackdaw flight performance were made with existing theory of gliding flight. We also re-analysed data on span ratios with respect to speed in two other bird species previously studied in wind tunnels. These data indicate that an equation for calculating the span ratio, which minimises the sum of induced and profile drag, does not predict the actual span ratios observed in these birds. We derive an alternative equation on the basis of the observed span ratios for calculating wingspan and wing area with respect to forward speed in gliding birds from information about body mass, maximum wingspan, maximum wing area and maximum coefficient of lift. These alternative equations can be used in combination with any model of gliding flight where wing area and wingspan are considered to calculate sinking rate with respect to forward speed.
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Thahir, Muhammad Agam, Irwandy Syofyan, and Isnaniah Isnaniah. "PENGUJIAN SINKING SPEED SERAT ALAMI." JURNAL PERIKANAN TROPIS 4, no. 1 (April 1, 2017): 93. http://dx.doi.org/10.35308/jpt.v4i1.59.
Повний текст джерелаАнотація:
The aim of this study to determine the elongation of three types of natural fibers. The method used is an experiment, by directly testing samples of the rope in the aquarium. Sinking speed value of banana stem fiber is 4.8 cm / sec, pandan leaves 3.9 cm / sec, bundung grass fibers 2.6 cm / sec. The third of these natural fibers, banana stem fibers that have the potential as for natural fibre rope material fishing gear.
4
Shan, Chenxu, Hao Tang, Nyatchouba Nsangue Bruno Thierry, Wei Liu, Feng Zhang, Meixi Zhu, Can Zhang, Liuxiong Xu, and Fuxiang Hu. "Sinking Behavior of Netting Panels Made with Various Twine Materials, Solidity Ratios, Knot Types, and Leadline Weights in Flume Tank." Journal of Marine Science and Engineering 11, no. 10 (October 12, 2023): 1972. http://dx.doi.org/10.3390/jmse11101972.
Повний текст джерелаАнотація:
Netting is an important component of fishing gear design, and its ability to sink determines the effectiveness of fishing gears such as purse seines, falling nets, and stick-held nets. Therefore, it is crucial to thoroughly investigate the sinking parameters (sinking depth and sinking speed) of the netting panel as a function of the leadline weights using various twine materials, knot types, and solidity ratios. In this study, a generalized additive model (GAM) was utilized to analyze the impact of each factor on the sinking performances of the netting. The results revealed that the sinking depth of the netting was positively correlated with sinking time and leadline weight. However, the netting featured a maximum sinking depth limit, indicating that the sinking depth would not increase beyond a leadline weight of 69.5 g. During the initial phase of the sinking process, the sinking velocity of each netting panel initially increased but gradually decreased over time. The incorporation of a leadline weight reduced sinking time. Thereby, polyester netting exhibited the shortest average sinking time. A comparison of netting types with similar solidity ratios showed that the maximum sinking depth of the nylon netting was 13.20% and 10.11% greater than that of polyethylene and polyester nettings, respectively. In addition, nylon nets’ time average sinking speed was 64.58% and 4.62% greater than that of polyethylene and polyester nettings, respectively. The analysis of the GAM model clearly showed that the leadline weight has a significant effect on the netting sinking speed and depth. To ensure that the netting can reach its maximum sinking speed, it is strongly recommended to use nylon and polyester nettings with a low solidity ratio, i.e., a lower twine diameter and greater mesh size with a higher leadline weight, when constructing fishing gear such as purse seines with higher net leadline weights.
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Spilling, Kristian, Malte Heinemann, Mari Vanharanta, Moritz Baumann, Andrea Noche-Ferreira, Philipp Suessle, and Ulf Riebesell. "Respiration rate scales inversely with sinking speed of settling marine aggregates." PLOS ONE 18, no. 3 (March 1, 2023): e0282294. http://dx.doi.org/10.1371/journal.pone.0282294.
Повний текст джерелаАнотація:
Sinking marine aggregates have been studied for a long time to understand their role in carbon sequestration. Traditionally, sinking speed and respiration rates have been treated as independent variables, but two recent papers suggest that there is a connection albeit in contrasting directions. Here we collected recently formed (<2 days old) aggregates from sediment traps mounted underneath mesocosms during two different experiments. The mesocosms were moored off Gran Canaria, Spain (~ 27.9 N; 15.4 E) in a coastal, sub-tropical and oligotrophic ecosystem. We determined the respiration rates of organisms (mainly heterotrophic prokaryotes) attached to aggregates sinking at different velocities. The average respiration rate of fast sinking aggregates (>100 m d-1) was 0.12 d-1 ± 0.08 d-1 (SD). Slower sinking aggregates (<50 m d-1) had on average higher (p <0.001) and more variable respiration rates (average 0.31 d-1 ± 0.16 d-1, SD). There was evidence that slower sinking aggregates had higher porosity than fast sinking aggregates, and we hypothesize that higher porosity increase the settlement area for bacteria and the respiration rate. These findings provide insights into the efficiency of the biological carbon pump and help resolve the apparent discrepancy in the recent studies of the correlation between respiration and sinking speed.
6
Kloos, Heidi, and Guy C. Van Orden. "Can a Preschooler’s Mistaken Belief Benefit Learning?" Swiss Journal of Psychology 64, no. 3 (September 2005): 195–205. http://dx.doi.org/10.1024/1421-0185.64.3.195.
Повний текст джерелаАнотація:
Young children erroneously believe that differences either in mass alone or in volume alone can predict differences in sinking speed. The current study was an attempt to teach preschool children that neither mass nor volume alone is predictive for sinking speed. Instead, it is the average density of an object that can predict differences in sinking speed. Twenty-four 4-to 6-year-olds participated. In an initial phase, children’s mistaken beliefs about the effects of mass and volume on sinking speed were called to their minds. Then they were presented with demonstrations of sinking objects that disconfirmed these mistaken beliefs. The findings show that preschool children can replace mistaken beliefs and learn that two dimensions, originally thought of as being relevant, are indeed irrelevant. Children who did not perform correctly demonstrated a mass bias. The results also shed light on the origins of this bias.
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Fitri, Amraini, Nofrizal Nofrizal, Romie Jhonnerie, and Fauzan Ramadhan. "Absorption and Sinking Speed of Artocarpus Stems Rope (Artocarpus sp.) and Carex Grass Rope (Carex sp.) in Freshwater and Seawater." Jurnal Perikanan dan Kelautan 27, no. 3 (October 4, 2022): 354. http://dx.doi.org/10.31258/jpk.27.3.354-357.
Повний текст джерелаАнотація:
Artocarpus stems (Artocarpus sp.) and Carex grass (Carex sp.) have not been applied to fishing gear materials. The fibers produced made into a rope, where this rope is used to absorption and sinking speed test in fresh water and sea water.The absorption of Artocarpus stems rope was 320.30% and 282,60% in fresh water and sea water. Meanwhile for sinking speed have a 5,78 cm/s and 5,08 cm/s for fresh water and sea water. For the Carex grass rope, the absorption in fresh water and sea water was 287,67% and 218,02%. Sinking speed value 2,97 cm/s and 2,67 cm/s for fresh water and sea water. The value of absorption and sinking speed in fresh water is higher than in sea water for both types of rope
8
Bergan, Alexander J., Gareth L. Lawson, Amy E. Maas, and Zhaohui Aleck Wang. "The effect of elevated carbon dioxide on the sinking and swimming of the shelled pteropod Limacina retroversa." ICES Journal of Marine Science 74, no. 7 (March 31, 2017): 1893–905. http://dx.doi.org/10.1093/icesjms/fsx008.
Повний текст джерелаАнотація:
Abstract Shelled pteropods are planktonic molluscs that may be affected by ocean acidification. Limacina retroversa from the Gulf of Maine were used to investigate the impact of elevated carbon dioxide (CO2) on shell condition as well as swimming and sinking behaviours. Limacina retroversa were maintained at either ambient (ca. 400 µatm) or two levels of elevated CO2 (800 and 1200 µatm) for up to 4 weeks, and then examined for changes in shell transparency, sinking speed, and swimming behaviour assessed through a variety of metrics (e.g. speed, path tortuosity, and wing beat frequency). After exposures to elevated CO2 for as little as 4 d, the pteropod shells were significantly darker and more opaque in the elevated CO2 treatments. Sinking speeds were significantly slower for pteropods exposed to medium and high CO2 in comparison to the ambient treatment. Swimming behaviour showed less clear patterns of response to treatment and duration of exposure, but overall, swimming did not appear to be hindered under elevated CO2. Sinking is used by L. retroversa for predator evasion, and altered speeds and increased visibility could increase the susceptibility of pteropods to predation.
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Kriest, I., and A. Oschlies. "On the treatment of particulate organic matter sinking in large-scale models of marine biogeochemical cycles." Biogeosciences 5, no. 1 (January 25, 2008): 55–72. http://dx.doi.org/10.5194/bg-5-55-2008.
Повний текст джерелаАнотація:
Abstract. Various functions have been suggested and applied to represent the sedimentation and remineralisation of particulate organic matter (POM) in numerical ocean models. Here we investigate some representations commonly used in large-scale biogeochemical models: a constant sinking speed, a sinking speed increasing with depth, a spectrum of particles with different size and different size-dependent sinking velocities, and a model that assumes a power law particle size distribution everywhere in the water column. The analysis is carried out for an idealised one-dimensional water column, under stationary boundary conditions for surface POM. It focuses on the intrinsic assumptions of the respective sedimentation function and their effect on POM mass, mass flux, and remineralisation profiles. A constant and uniform sinking speed does not appear appropriate for simulations exceeding a few decades, as the sedimentation profile is not consistent with observed profiles. A spectrum of size classes, together with size-dependent sinking and constant remineralisation, causes the sinking speed of total POM to increase with depth. This increase is not strictly linear with depth. Its particular form will further depend on the size distribution of the POM ensemble at the surface. Assuming a power law particle size spectrum at the surface, this model results in unimodal size distributions in the ocean interior. For the size-dependent sinking model, we present an analytic integral over depth and size that can explain regional variations of remineralisation length scales in response to regional patterns in trophodynamic state.
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Kriest, I., and A. Oschlies. "On the treatment of particulate organic matter sinking in large-scale models of marine biogeochemical cycles." Biogeosciences Discussions 4, no. 4 (August 28, 2007): 3005–40. http://dx.doi.org/10.5194/bgd-4-3005-2007.
Повний текст джерелаАнотація:
Abstract. Various functions have been suggested and applied to represent the sedimentation and remineralisation of particulate organic matter (POM) in numerical ocean models. Here we investigate some representations commonly used in large-scale biogeochemical models: a constant sinking speed, a sinking speed increasing with depth, a spectrum of particles with different size and different size-dependent sinking velocities, and a model that assumes a power-law particle size distribution everywhere in the water column. The analysis is carried out for an idealised one-dimensional water column, under stationary boundary conditions for surface POM. It focuses on the intrinsic assumptions of the respective sedimentation function and their effect on POM mass, mass flux, and remineralisation profiles. A constant and uniform sinking speed does not appear appropriate for simulations exceeding a few decades, as the sedimentation profile is not consistent with observed profiles. A spectrum of size classes, together with size-dependent sinking and constant remineralisation, causes the sinking speed of total POM to increase with depth. This increase is not strictly linear with depth. Its particular form will further depend on the size distribution of the POM ensemble at the surface. Assuming a power-law particle size spectrum at the surface, this model results in unimodal size distributions in the ocean interior. For the size-dependent sinking model, we present an analytic integral over depth and size that can explain regional variations of remineralisation length scales in response to regional patterns in trophodynamic state.
Дисертації з теми "Sinking speed"
1
Laget, Manon. "Rôle des Rhizaria dans les cycles biogéochimiques de l’océan épi- et mésopélagique." Electronic Thesis or Diss., Littoral, 2023. http://www.theses.fr/2023DUNK0690.
Повний текст джерелаАнотація:
Les océans épipélagique et mésopélagique jouent un rôle clé dans la production, le recyclage et le transfert de la matière organique et minérale vers l’océan profond. Les Rhizaria (comprenant les Radiolaria et les Phaeodaria) sont des protistes planctoniques qu’on retrouve dans ces couches de l’océan mondial. Ils peuvent être mixotrophes ou hétérotrophes, et certains d’entre eux forment des squelettes de silice. De plus, ces organismes peuvent agréger du matériel détritiques autour d’eux, formant ainsi des particules sédimentant rapidement. L’échantillonnage de ces organismes fragiles est difficile par le biais de méthodes traditionnelles comme les filets à plancton, mais les avancées en imagerie in situ ont amélioré les estimations de leur abondance et de leur rôle dans les flux élémentaires. Cependant, en raison du manque de mesures au niveau cellulaire, notre compréhension de leur biomasse mondiale en carbone et de leur rôle dans les processus biogéochimiques reste limitée. Pour combler ces lacunes, le contenu en carbone de divers taxons de Rhizaria a été mesuré, couvrant un large spectre de tailles, et une relation allométrique a été établie, révélant une densité de carbone globalement faible par rapport aux protistes plus petits. À l’aide de boosted regression trees et d’un ensemble de données global collecté à l’aide de l’Underwater Vision Profiler (UVP) 5, comprenant plus de 167 000 images de Rhizaria enregistrées dans le monde entier, la biomasse mondiale en carbone des Rhizaria >600 μm a été ré-estimée à 1,7 % de la biomasse totale du mésozooplancton dans les 500 premiers m de la colonne d’eau. Cette biomasse s’est révélée être dix fois plus élevée dans la zone mésopélagique que dans la zone épipélagique. Ensuite, il a été estimé que les Phaeodaria mésopélagiques, se nourrissant du flux de particules, peuvent intercepter de 3,8 à 9,2 % du flux de carbone particulaire exporté de la zone euphotique. Dans l’océan Austral, où leur abondance était précédemment considérée faible, ce taux d’interception est de 11,2-23,4 %. De plus, les taux de production de silice biogénique (bSi) des Phaeodaria ont été estimés, constituant la première quantification de la production de bSi dans la zone mésopélagique. En tant que seuls producteurs de bSi dans cette zone, ils jouent un rôle significatif dans son recyclage, co-dominant le cycle du silicium aux côtés des diatomées et des éponges. Enfin, une nouvelle méthodologie pour mesurer la vitesse de sédimentation des particules marines à l’aide de l’UVP6 monté sur un piège à sédiments a été introduite. Après la collecte d’environ 9 000 valeurs de vitesse de sédimentation dans l’Atlantique Nord, aucune relation forte n’a été trouvée entre les mesures morphologiques fournies par l’UVP6 et celles-ci. Au lieu de cela, il a été observé que les vitesses de sédimentation augmentent avec la profondeur et sont influencées par les conditions environnementales. Ces résultats mettent en évidence l’importance de prendre en compte la composition des communautés phytoplanctoniques et zooplanctoniques, pour estimer la vitesse et affiner les estimations de flux qui utilisent l’imagerie in situThe epipelagic and mesopelagic oceans play a key role in the production, recycling, and transfer of both organic and mineral matter to the deep ocean. Rhizaria (including Radiolaria and Phaeodaria) are planktonic protists thriving in these layers throughout the world ocean. They can display either mixotrophic or heterotrophic feeding behavior, and some of them form silica skeletons. Furthermore, these organisms can aggregate detrital material around them, forming fast-sinking particles. Sampling these fragile organisms is challenging, but advances in in situ imaging techniques have improved estimates of their abundance and roles in element fluxes. Still, due to a lack of measurements at the cellular level, our understanding of their global carbon biomass and their roles in biogeochemical processes remains limited. To fill this gap, the carbon content of diverse rhizarian taxa was measured, covering a broad size spectrum, and an allometric relationship was established, revealing an overall low carbon density compared to smaller protists. Using boosted regression trees and a global Underwater Vision Profiler (UVP) 5 dataset, including >167,000 rhizarian images recorded all over the world ocean, global carbon biomass of >600-μm Rhizaria was reestimated to be 1.7% of the total mesozooplankton biomass within the upper 500 m of the water column. This biomass was found to be 10-fold higher in the mesopelagic than in the epipelagic layer. Subsequently, mesopelagic flux-feeder Phaeodaria were estimated to intercept 3.8-9.2% of the gravitational POC flux exported out of the euphotic zone. In the Southern Ocean, where their abundance was previously shown to be low, this interception rate can reach as high as 11.2-23.4%. In addition, biogenic silica (bSi) production rates of Phaeodaria were estimated, being the first quantification of bSi production in the mesopelagic layer. As the sole bSi producers in this layer, they play a significant role in its recycling, co-dominating the silicon cycle along with diatoms and sponges. Lastly, a new methodology to measure the sinking speed of marine particles using the UVP6 mounted on a sediment trap was introduced. After collecting approx. 9,000 measurements of particle sinking speeds in the North Atlantic, no strong relationships were found between morphological measurements provided by the UVP6 and sinking speeds. Instead, it was observed that sinking speeds increased with depth and were influenced by environmental conditions. These results highlight the importance of considering community composition, including both phytoplankton and zooplankton, for speed estimation and to refine flux estimates using in situ imaging
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Бондаренко, М. О. "Наукові основи створення алмазного бурового інструменту з підвищеною роботоздатністю". Thesis, Івано-Франківський національний технічний університет нафти і газу, 2007. http://elar.nung.edu.ua/handle/123456789/4162.
Повний текст джерелаАнотація:
Розроблено нові теоретичні підходи для створення алмазного бурового інструменту з підвищеною роботоздатністю на основі аналітичних методів дослідження температурних полів, термопружного стану, зношування та фізико-хімічних процесів, які відбуваються при спіканні робочих елементів методом гарячого пресування. Ці підходи дозволяють визначити основні фактори, що впливають на кінетику даних процесів, спрогнозувати структуру і властивості НКАМ, зносостійкість і довговічність бурових інструментів на їх основі. Проведені розрахунки енергетичного стану зразків бурових вставок складу алмаз - твердий сплав ВК6 при їх спіканні методом гарячого пресування дозволили визначити оптимальний хімічний склад і р -Т - t умови, за яких відбувається покращання структури і властивостей композита. На основі запропонованих моделей встановлено закономірності температурних полів, термопружного стану та кінетики зношування алмазних доліт ІНМ-214,3 Т при бурінні міцних і абразивних гірських порід для різних теплофізичних і механічних умов, що є дуже важливим для вдосконалення технології виготовлення бурових інструментів і практики їх експлуатації.
Порівняння розрахункових даних з експериментальними вказує на адекватність розроблених моделей і точність отриманих результатів. На основі наукових досліджень розроблено конструкції бурових інструментів, які успішно впроваджені в промислове виробництво і показали результати при бурінні нафтових і газових свердловин на рівні кращих зразків закордонного виробництва.Проанализированы различные концепции и современное состояние теории износа и технологии изготовления сверхтвердых композиционных алмазосодержащих материалов состава алмаз - твердый сплав ВК6, сложившуюся в настоящее время. Разработаны новые теоретические подходы к созданию алмазного бурового инструмента на основе аналитических методов исследования температурных полей, термоупругих напряжений, износа и физико-химических процессов, происходящих при спекании композита методом горячего прессования. Сформулированы научные направления в области сверхтвердых композитов - от качества приготовления породоразрушающих элементов, требуемой структуры и свойств до разработки конкурентноспособных на мировом рынке буровых инструментов на их основе. Для иллюстрации полученных общих решений проведен их анализ для конкретных условий работы инструмента при варьировании физико-механических свойств композита, микрогеометрических характеристик алмазов и их концентрации, сферических координат профиля, условий бурения й охлаждения. Впервые сформулирована и решена нестационарная задача теплопроводности для полусферического тела с покрытием, из которого удален сферический сектор с центром в начале координат. Она моделирует температурное состояние алмазного бурового долота, при котором теплофизические характеристики рабочей поверхности существенно отличаются от аналогичных для корпуса долота. Модель учитывает интенсивное тепловыделение вследствие трения в зоне контакта инструмент -порода и охлаждение жидкостью за счет конвективного теплообмена. Для ее решения использован метод Галеркина в гильбертовом пространстве с разложением функций по собственным функциям спектральных задач с параметром в уравнении и граничном условии. На основе полученного решения проведен анализ зависимости температурных полей в алмазном долоте ИСМ-214,3 Т при бурении твердых и абразивных горных пород от теплофизических свойств материала композита и корпуса, микрогеометрических характеристик алмазов, относительного значения коэффициента теплообмена, режимов бурения, радиальной и угловой координат профиля. Полученные результаты представляют научный интерес и имеют прикладное значение для создания и анализа работы долот из сверхтвердых материалов. Впервые разработана математическая модель для описания физико-химических процессов, которые параллельно происходят при спекании алмазосодержащих композитов на основе твердосплавных матриц для общего случая, когда скорость процесса контролируется как диффузией, так и химической реакцией. Показано, что комплексное применение известных и предложенной моделей с использованием методов рентгеноспектрального анализа позволяет глубже исследовать кинетику физико-химических процессов на различных этапах спекания и выявить основные факторы, влияющие на их протекание. Предложено в качестве меры качества готовых изделий принять энергии активации процессов, зародышеобразования новых фаз, химических реакций между компонентами и кинетические параметры процесса спекания. Статистическая достоверность опытных и модельных расчетов свидетельствует о адекватности модели и точности полученных результатов. На основании полученных результатов разработаны конкурентоспособные на мировом рынке сверхтвердые композиционные алмазосодержащие материалы и буровые инструменты на их основе.
The new theoretical approaches have been developed of making the diamond drilling tools with increased efficiency based on the analytical methods of investigating the temperature fields, thermoelastic stress, wear and physico-chemical processes taking a place during the hot pressing of working bits. These approaches allow to detect the leading factors influencing the kinetics of the given processes and to predict the structure and properties of superhard composite materials, wear resistance and durability of drilling tools equipped with them. The energy state calculations conducted of drtilling inserts made of diamond and WC-бСо hard allloy by hot pressing made it possible to determine the optimal chemistry and p - T -1 conditions providing improvement of structure and properties of composite. Using the proposed models, the patterns have been established of temperature fields, thermoelastic stress and wear kinetics of IHM-214,3T diamond drills under the conditions of hard and abrasive rock drilling for various thermal and mechanical situations being crucial for production techology of these tools and their running practice. Comparison of calculated and exparimental data indicates adequateness of the developed models and accuracy of the obtained results. Based on the scientific investigations, the drilling tools have been designed and applied sucsessfully in industry for the oil and gas well drilling and have shown the results at the level of the best foreign-made tools.
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huang, jian-hao, and 黃建豪. "The Study of Control on High Speed Deep-Sinking EDM Using OPLC." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/48104755266892049409.
Повний текст джерелаАнотація:
碩士大葉大學
機電自動化研究所碩士班
95
The study to use the fuji electric’s open architecture controller prescribed in Structured Text program to develop Deep-sinking EDM CNC which has high speed Drilling EDM function . In order to erode a blind hole , the wear compensation is necessary . The occurate depth can be obtained . After deep-sinking eroding , the finishing for the wall can be , and executed through a vector motion . In order to achieve the working goal , it will establish the controller in the OPLC which includes the gap sensor , electrode compensation , interpolator , position control , parameter transmission I/O logic control . In order to obtain the algorithm for the wear to compensation , the using taguchi’s statistical analysis is need to analyze process error . On a personal compute , establishes the operator interface using Visual Basic let to allow the picture for operating the EDM , which can transfer the block parameters to OPLC . Finally this control system equip on the deep drilling EDM , and actual processing and the functions an test . The final results shows the dimension and roughness of the deep hole can be obtained .
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Yang, Ching-Min, and 楊清閔. "Studies on the reduction of the seabird bycatch in tuna longline fishery -Relationship between the fishing gear and methods and the bait sinking speed-." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/47208744910079684636.
Повний текст джерелаКниги з теми "Sinking speed"
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Konstam, Angus, and Tony Bryan. River Plate 1939: The Sinking of the Graf Spee. Bloomsbury Publishing Plc, 2016.
Знайти повний текст джерелаЧастини книг з теми "Sinking speed"
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Whiteman, C. David. "Pressure and Winds." In Mountain Meteorology. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195132717.003.0012.
Повний текст джерелаАнотація:
Atmospheric pressure at a given point in the atmosphere is the weight of a vertical column of air above that level. Differences in pressure from one location to another cause both horizontal motions (winds) and vertical motions (convection and subsidence) in the atmosphere. Vertical motions, whether associated with high and low pressure centers or with other meteorological processes, are the most important motions for producing weather because they determine whether clouds and precipitation form or dissipate. The location of high and low pressure centers is a key feature on weather maps, providing information about wind direction, wind speed, cloud cover, and precipitation. Pressure-driven winds carry air from areas where pressure is high to areas where pressure is low. However, the winds do not blow directly from a high pressure center to a low pressure center. Because of the effects of the rotation of the earth and friction, winds blow clockwise out of a high pressure center and counterclockwise into a low pressure center in the Northern Hemisphere. These wind directions are reversed in the Southern Hemisphere. The strength of the wind is proportional to the pressure difference between the two regions. When the pressure difference or pressure gradient is strong, wind speeds are high; when the pressure gradient is weak, wind speeds are low. As air flows out of a high pressure center, air from higher in the atmosphere sinks to replace it. This subsidence produces warming and the dissipation of clouds and precipitation. As air converges in a low pressure center, it rises and cools. If the air is sufficiently moist, cooling can cause the moisture to condense and form clouds. Further lifting of the air can produce precipitation. Thus, rising pressure readings at a given location indicate the approach of a high pressure center and fair weather, whereas falling pressure readings indicate the approach of a low pressure center and stormy weather. The vertical motions caused by the divergence of air out of a high pressure center or the convergence of air into a low pressure center are generally weak, with air rising or sinking at a rate of several cm per second, and they cannot be measured by routine weather observations.
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Hofmeister, Anne M., Robert E. Criss, and Everett M. Criss. "Links of planetary energetics to moon size, orbit, and planet spin: A new mechanism for plate tectonics." In In the Footsteps of Warren B. Hamilton: New Ideas in Earth Science. Geological Society of America, 2022. http://dx.doi.org/10.1130/2021.2553(18).
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ABSTRACT Lateral accelerations require lateral forces. We propose that force imbalances in the unique Earth-Moon-Sun system cause large-scale, cooperative tectonic motions. The solar gravitational pull on the Moon, being 2.2× terrestrial pull, causes lunar drift, orbital elongation, and an ~1000 km radial monthly excursion of the Earth-Moon barycenter inside Earth’s mantle. Earth’s spin superimposes an approximately longitudinal 24 h circuit of the barycenter. Because the oscillating barycenter lies 3500–5500 km from the geocenter, Earth’s tangential orbital acceleration and solar pull are imbalanced. Near-surface motions are enabled by a weak low-velocity zone underlying the cold, brittle lithosphere: The thermal states of both layers result from leakage of Earth’s internal radiogenic heat to space. Concomitantly, stress induced by spin cracks the lithosphere in a classic X-pattern, creating mid-ocean ridges and plate segments. The inertial response of our high-spin planet with its low-velocity zone is ~10 cm yr–1 westward drift of the entire lithosphere, which largely dictates plate motions. The thermal profile causes sinking plates to thin and disappear by depths of ~200–660 km, depending on angle and speed. Cyclical stresses are effective agents of failure, thereby adding asymmetry to plate motions. A comparison of rocky planets shows that the presence and longevity of volcanism and tectonism depend on the particular combination of moon size, moon orbital orientation, proximity to the Sun, and rates of body spin and cooling. Earth is the only rocky planet with all the factors needed for plate tectonics.
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Dallek, Robert. "Muddling Through." In Franklin D. Roosevelt and American Foreign Policy, 1932-1945, 101–21. Oxford University PressNew York, NY, 1995. http://dx.doi.org/10.1093/oso/9780195097320.003.0006.
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Abstract IN THE THREE MONTHS after the Senate rejected membership in the World Court, events abroad fanned American fears of war. In February 1935, Mussolini responded to a two-month-old border dispute with Ethiopia by sending additional forces to Italian East Africa. In March, Berlin openly repudiated the disarmament clauses of the Versailles Treaty by revealing the existence of a German air force and plans to build a 550,000-man army. In response, France doubled the existing period of service for conscripts, and the League voted to consider economic and financial measures against any state endangering the peace. “These are without doubt the most hair-trigger times the world has gone through in your lifetime or mine,” FDR wrote• Ambassador Breckinridge Long in Rome. “I do not even exclude June and July 1914.”These developments, coupled with a $1.1 billion defense request by FDR, the largest peacetime budget in American history, stirred American pacifists to fresh actions. “We are rapidly sinking to the level of Hitler and Mussolini in our bowing down before the God of war,” Oswald Garrison Villard, the editor of the Nation,complained. “That a Chris tian nation such as we pretend to be ... is actually planning to spend $1,125,000,000 ... upon military and naval expenditures ... when . . . more than 20,000,000 Americans are on the bread line and in receipt of doles, is one of the most humiliating and discouraging happenings of recent years.” Arguing that the United States was in no danger of invasion, students, clergymen, and women’s groups warned that so large a defense budget signified an intent to make war.
Тези доповідей конференцій з теми "Sinking speed"
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Fu, JianYu, GuoLong Zhang, TingHui Gao, and You Wang. "Washing type air purifier based on selective sinking speed bump." In 2021 7th International Symposium on Mechatronics and Industrial Informatics (ISMII). IEEE, 2021. http://dx.doi.org/10.1109/ismii52409.2021.00033.
Повний текст джерела
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Hsue, Albert Wen-Jeng, and Chih-Hung Chung. "Control strategy for high speed electrical discharge machining (die-sinking EDM) equipped with linear motors." In 2009 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM). IEEE, 2009. http://dx.doi.org/10.1109/aim.2009.5229994.
Повний текст джерела
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Abe, Tadayuki, Akira Takasaki, Kazuki Watanabe, and Kazuhiko Matsuoka. "Analysis of Milling Mechanism by Ball End-Mill and Development of High Speed Die-Sinking Method." In Passenger Car Meeting & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1988. http://dx.doi.org/10.4271/881742.
Повний текст джерела
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Schacht, Benny, Raf Verheyen, Jean-Pierre Kruth, and Bert Lauwers. "An Erosion Index for Wire Electrode Materials in EDM." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60798.
Повний текст джерелаАнотація:
In this paper, the authors propose an erosion index for wire materials or wire coatings. In sinking EDM research and practice, an erosion index is commonly available. In wire EDM few efforts have been made to identify possible electrode materials from the point of view of cutting speed. The index is based on physical understanding of the process and uses thermal properties of the electrode material, as is the case for the sinking EDM erosion index. The most important materials used as a coating for wire electrodes, like Zn, Cu, W and Mo, are analyzed and the proposed index is in good correlation with experimental cutting data, both from literature reports and own experiments. The theory can also be applied to alloys, such as brass (Cu-Zn) with different amounts of zinc.
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Nowald, N., G. Fischer, V. Ratmeyer, M. Iversen, C. Reuter, and G. Wefer. "In-situ sinking speed measurements of marine snow aggregates acquired with a settling chamber mounted to the Cherokee ROV." In OCEANS 2009-EUROPE (OCEANS). IEEE, 2009. http://dx.doi.org/10.1109/oceanse.2009.5278186.
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Ramos, Antonio, Antonio J. Bula, and Maria Cely. "Experimental Study of Single-Phase Heat Transfer in Circular Milli-Channels for Cooling of Micro Components." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-82438.
Повний текст джерелаАнотація:
The increase of processing speed in applications such as servers, laptops and workstations requires heat-sinking technologies with higher levels of power dissipation than the current methods. For this reason, this paper presents an experimental study of heat transfer in water-cooled milli - channel heat sinks. The experimental process consists of fabrication and testing of rectangular plates with multiple parallel channels oriented in the flow direction. Variations in the number of channels, channel diameter, and volumetric flow were considered in order to study the conjugate heat transfer phenomena. Overall heat transfer coefficients in single-phase flow regimes are presented and analyzed.
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Mourad, Abdel-Hamid I., Khalifa H. Harib, and Aly El-Domiaty. "Fracture Behavior of Friction Stir Spot Welded Joint." In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25986.
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The fracture behaviour of lap-shear joints manufactured by friction stir spot welding (FSSW) technique is examined in this paper. Two aluminium sheets of 2.8 mm thickness were welded using different process parameters to form a lap-shear joint. Special tool was designed and fabricated for the stir-spot welding process. Tensile-shear tests were performed to determine the tensile-shear load bearing capacity and toughness of the weld. The stress intensity factor and the J-integral around a weld are determined in order to characterize the fracture behavior. The effect of different main process controlling parameters, e.g., the tool prop pin rotating speed, duration action time and sinking/penetration depth into the lower welded sheet on the weld fracture behaviour has been investigated through an intensive experimental program. Optical and scanning electron microscopes fractographes were obtained to examine the weld fracture modes. The results show that higher frictional heat due to relatively higher tool probe pin rotational speed and penetration depth into the lower sheet produces improved joint static strength and toughness.
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Yokoyama, Masao, Yoshihiro Kubota, and Osamu Mochizuki. "Effects of Wall Condition of a Plunging Body on Splash." In ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajk2011-03076.
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Splashes generated by hydrogel sphere were simulated numerically and experimentally for investigating the effects of slip like mucus of living things. Numerical simulation using MPS (Moving Particle Semi-implicit) method was carried out. We defined the slip ratio as the swelling degree of hydrogel and installed the slip ratio into the MPS method. The swelling degree is the ratio of the weight of water against that of hydrogel. We simulated the splashes generated by the hydrogel spheres which had the different swelling degree plunging into water. As the evaluation of swelling degree on the surface of actual hydrogel spheres we also tested by using the hydrogel spheres plunging into water experimentally. The height of splash as a result of reaction of the air cavity became higher according to the increase of the swelling degree. The speed of hydrogel sphere sinking in water tank was also quicker in the numerical simulation. The reason of these results was that the velocity of water around the hydrogel sphere became quicker due to the slip on the surface.
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Lin, Steven, Demetri Psaltis, and Jae Kim. "High-gain GaAs optoelectronic thresholding devices for neural network implementation." In Integrated Photonics Research. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/ipr.1991.tuc1.
Повний текст джерелаАнотація:
The optical implementation of a neural network consists of two basic components: a 2-D array of neurons and interconnections. Each neuron is a nonlinear processing element that, in its simplest form, produces an output which is the thresholded version of the input. Monolithic optoelectronic integrated devices are candidates for these neurons. However, in order for these devices to be used as neurons in a practical experiment, they must be large in number (104/cm2 - 106/cm2) and exhibit high gain. This puts a stringent requirement on the electrical power dissipation. Thus, these devices have to be operated at low enough current levels so that the power dissipation on the chip does not exceed the heat-sinking capability, and yet the current levels need to be large enough to be able to produce high gain. This means sensitive input devices are a must. To achieve these goals, the speed requirement of the devices must be relaxed as the operation of neural network does not have to be too fast.
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Cunningham, James, and Conrad S. Tucker. "A Validation Neural Network (VNN) Metamodel for Predicting the Performance of Deep Generative Designs." In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-86299.
Повний текст джерелаАнотація:
This work presents a deep neural network method for approximating the performance of generated design concepts. This deep learning meta-modeling approach minimizes the need for costly simulations that test for design concept feasibility by discovering the visual features of a design that correlated to good and bad performance. These form-function relationships are discovered by simply observing the pixels of images of many candidate designs and their corresponding performance in a simulation environment. As opposed to existing metamodeling techniques, this evaluation is agnostic to the simulation environment and applicable to any design space in which form and function are closely linked. A case study is presented in which 2D sketches of boats generated from a deep generative model are evaluated in a simulation environment based on their ability to travel through water without sinking as well as their speed of travel. It is shown through simulation that 57.5% of the designs, which are validated according to their form during the generation process, fail in their intended function. Additionally, the trained VNN is able to classify designs it has never seen before as successful or failing with an accuracy of 86.6% and an F1-Score of 0.806.