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Alexey V Chernyshev - One of the best experts on this subject based on the ideXlab platform.
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deep Sea epibiotic hydroids from the abyssal plain adjacent to the kuril kamchatka trench with description of garveia belyaevi sp nov hydrozoa bougainvilliidae
Deep-sea Research Part Ii-topical Studies in Oceanography, 2015Co-Authors: Sofia D Stepanjants, Alexey V ChernyshevAbstract:Examination of material collected by the German–Russian KuramBio Deep-Sea Expedition to the abyssal plain adjacent to the Kuril–Kamchatka Trench revealed about 17 hydroid species, including two species presumably new to science. Before the KuramBio Expedition only fragments of the unidentified hydroids and Cryptolaria sp. were collected in the Kuril–Kamchatka Trench from depths exceeding 3000 m. Descriptions of three species of epibiotic hydroids (including one new species, Garveia belyaevi sp. nov.) are presented herein. A colony of G. belyaevi sp. nov. (the third deep-Sea and deepest species of the wide distributed genus Garveia) was attached to the spines of unidentified Irregular Sea urchins from depths 5217 to 5229 m. Нalitholus (?) sp. (Hydrozoa, Anthoathecata) colonized the skin of spoon worms (Echiura) but could not be identified to species level because the mature medusa stage was absent in the material. An unidentified juvenile polyp (Pandeidae) was found on the bryozoan Tricitella minini attached to spines of Irregular Sea urchins Echinosigra amphora. Colonial sedentary organisms inhabiting abyssal plains with soft bottoms may colonize invertebrates which are seldom used as substrates for epibiota in shallow waters. Epibiosis among abyssal colonial invertebrates, though extremely poorly studied, appears to be rather frequent.
Alexei V Chernyshev - One of the best experts on this subject based on the ideXlab platform.
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triticella minini a new ctenostome bryozoan from the abyssal plain adjacent to the kuril kamchatka trench
Deep-sea Research Part Ii-topical Studies in Oceanography, 2015Co-Authors: Andrei V Grischenko, Alexei V ChernyshevAbstract:A new species of ctenostome bryozoan, Triticella minini sp. nov., is described from the abyssal plain adjacent to the Kuril–Kamchatka Trench, based on material collected by the Russian-German deep-Sea expedition KuramBio 2012. Colonies of T. minini sp. nov. were found attached to the oral spines of Irregular Sea urchin Echinosigra (Echinogutta) amphora Mironov, 1974 by means of rhizoid fibers that penetrated the substratum through circular borings. The specimens were examined by light microscopy, scanning electron microscopy, and confocal laser scanning microscopy with phalloidin and nuclear labeling. The description of T. minini sp. nov. combines a general taxonomic description with a description of the anatomy of the muscular system. The new species differs from congeners in lacking a stolon. It has an intertentacular organ. T. minini sp. nov. is the eleventh species described in the genus Triticella Dalyell, 1848, and the first record for this genus from the northwestern Pacific. The new species is the fifth ctenostome bryozoan known to occur in 5001–5500 m depth interval worldwide, and the deepest record reported for Triticella.
Armando Blanco - One of the best experts on this subject based on the ideXlab platform.
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fatigue life prediction due to slug flow in extra long submarine gas pipelines using fourier expansion series
ASME 2009 28th International Conference on Ocean Offshore and Arctic Engineering, 2009Co-Authors: Euro Casanova, Orlando Pelliccioni, Armando BlancoAbstract:Some offshore gas production fields require transporting of production fluids through very long submarines pipelines, without a previous separation process. In these cases, a slug flow pattern may develop for some production conditions. Condensate slugs traveling in the pipeline, act as moving loads for the piping structure, especially for the unsupported pipe spans which can be of even hundreds of meters long, due to Irregular Sea bottom, therefore producing a dynamic response of the pipeline that in some cases may significantly reduce its fatigue life. In this work a previously presented model [1], which combines fluid equations for predicting slug characteristics and a structural finite element model of horizontal pipelines transporting slugs, is modified for reducing computational cost and to adapt fatigue life calculations to the case of submarine piping. In order to calculate maximum amplitudes of the dynamic response without a time integration scheme, it is considered that traveling slugs produce periodical loads in time for every spatial point of the pipeline, and consequently these loads may be expressed by means of Fourier expansion series. With these assumptions, a more realistic fatigue calculation for a diversity of pipelines conditions is obtained. Results show that for this improved model computational time is dramatically reduced, without a lost in precision, when compared to the previous model requiring a time integration process.Copyright © 2009 by ASME
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fatigue life prediction due to slug flow in extra long submarine gas pipelines
ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering, 2008Co-Authors: Rabih Kansao, Euro Casanova, Armando Blanco, Frank Kenyery, Mayela RiveroAbstract:Some offshore production fields require transporting of production fluids through very long submarines pipelines without a previous separation process. In the case of gas production, condensate will appear in the pipeline due to the pressure losses and low temperatures. For some production conditions a slug flow pattern may then develop in the pipeline, and because of the Irregular Sea bottom profile, there may be pipe unsupported spans of even hundreds of meters long. Therefore, slugs traveling in the pipeline will act as moving loads for the unsupported pipe, producing a dynamic response that in some cases might reduce the fatigue life of the pipeline. In this work, a finite element (FE) model of a pipeline transporting slugs has been developed and used to assess the fatigue life of a horizontal pipeline. Slug hydrodynamic characteristics have been obtained using Taitel & Barnea’s model. The structural FE model is based in Bernoulli beam elements where slugs, once they have been geometrically characterized, are input as moving loads traveling in the pipeline. The system dynamic response was calculated for different spans conditions and slugs characteristics corresponding to different gas-liquid ratios typical from gas field production conditions. Once a steady state condition was obtained in the dynamic response, mean and alternating stress levels were obtained for each analyzed case and introduced in fatigue formulae to obtain the fatigue life of the pipeline. Results show that for some production conditions and free span longitudes, fatigue life of pipeline may experience important reductions due to slug flow. These free spans are obviously most likely to happen in extra long submarines pipelines.Copyright © 2008 by ASME
Euro Casanova - One of the best experts on this subject based on the ideXlab platform.
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fatigue life prediction due to slug flow in extra long submarine gas pipelines using fourier expansion series
ASME 2009 28th International Conference on Ocean Offshore and Arctic Engineering, 2009Co-Authors: Euro Casanova, Orlando Pelliccioni, Armando BlancoAbstract:Some offshore gas production fields require transporting of production fluids through very long submarines pipelines, without a previous separation process. In these cases, a slug flow pattern may develop for some production conditions. Condensate slugs traveling in the pipeline, act as moving loads for the piping structure, especially for the unsupported pipe spans which can be of even hundreds of meters long, due to Irregular Sea bottom, therefore producing a dynamic response of the pipeline that in some cases may significantly reduce its fatigue life. In this work a previously presented model [1], which combines fluid equations for predicting slug characteristics and a structural finite element model of horizontal pipelines transporting slugs, is modified for reducing computational cost and to adapt fatigue life calculations to the case of submarine piping. In order to calculate maximum amplitudes of the dynamic response without a time integration scheme, it is considered that traveling slugs produce periodical loads in time for every spatial point of the pipeline, and consequently these loads may be expressed by means of Fourier expansion series. With these assumptions, a more realistic fatigue calculation for a diversity of pipelines conditions is obtained. Results show that for this improved model computational time is dramatically reduced, without a lost in precision, when compared to the previous model requiring a time integration process.Copyright © 2009 by ASME
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fatigue life prediction due to slug flow in extra long submarine gas pipelines
ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering, 2008Co-Authors: Rabih Kansao, Euro Casanova, Armando Blanco, Frank Kenyery, Mayela RiveroAbstract:Some offshore production fields require transporting of production fluids through very long submarines pipelines without a previous separation process. In the case of gas production, condensate will appear in the pipeline due to the pressure losses and low temperatures. For some production conditions a slug flow pattern may then develop in the pipeline, and because of the Irregular Sea bottom profile, there may be pipe unsupported spans of even hundreds of meters long. Therefore, slugs traveling in the pipeline will act as moving loads for the unsupported pipe, producing a dynamic response that in some cases might reduce the fatigue life of the pipeline. In this work, a finite element (FE) model of a pipeline transporting slugs has been developed and used to assess the fatigue life of a horizontal pipeline. Slug hydrodynamic characteristics have been obtained using Taitel & Barnea’s model. The structural FE model is based in Bernoulli beam elements where slugs, once they have been geometrically characterized, are input as moving loads traveling in the pipeline. The system dynamic response was calculated for different spans conditions and slugs characteristics corresponding to different gas-liquid ratios typical from gas field production conditions. Once a steady state condition was obtained in the dynamic response, mean and alternating stress levels were obtained for each analyzed case and introduced in fatigue formulae to obtain the fatigue life of the pipeline. Results show that for some production conditions and free span longitudes, fatigue life of pipeline may experience important reductions due to slug flow. These free spans are obviously most likely to happen in extra long submarines pipelines.Copyright © 2008 by ASME
Sofia D Stepanjants - One of the best experts on this subject based on the ideXlab platform.
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deep Sea epibiotic hydroids from the abyssal plain adjacent to the kuril kamchatka trench with description of garveia belyaevi sp nov hydrozoa bougainvilliidae
Deep-sea Research Part Ii-topical Studies in Oceanography, 2015Co-Authors: Sofia D Stepanjants, Alexey V ChernyshevAbstract:Examination of material collected by the German–Russian KuramBio Deep-Sea Expedition to the abyssal plain adjacent to the Kuril–Kamchatka Trench revealed about 17 hydroid species, including two species presumably new to science. Before the KuramBio Expedition only fragments of the unidentified hydroids and Cryptolaria sp. were collected in the Kuril–Kamchatka Trench from depths exceeding 3000 m. Descriptions of three species of epibiotic hydroids (including one new species, Garveia belyaevi sp. nov.) are presented herein. A colony of G. belyaevi sp. nov. (the third deep-Sea and deepest species of the wide distributed genus Garveia) was attached to the spines of unidentified Irregular Sea urchins from depths 5217 to 5229 m. Нalitholus (?) sp. (Hydrozoa, Anthoathecata) colonized the skin of spoon worms (Echiura) but could not be identified to species level because the mature medusa stage was absent in the material. An unidentified juvenile polyp (Pandeidae) was found on the bryozoan Tricitella minini attached to spines of Irregular Sea urchins Echinosigra amphora. Colonial sedentary organisms inhabiting abyssal plains with soft bottoms may colonize invertebrates which are seldom used as substrates for epibiota in shallow waters. Epibiosis among abyssal colonial invertebrates, though extremely poorly studied, appears to be rather frequent.