排序方式: 共有31条查询结果,搜索用时 15 毫秒
21.
Explosion pressure prediction via polynomial mathematical correlation based on advanced CFD Modelling 总被引:1,自引:0,他引:1
Sávio S.V. Vianna Robert Stewart Cant 《Journal of Loss Prevention in the Process Industries》2012,25(1):81-89
Computational Fluid Dynamics CFD can be used as a powerful tool supporting engineers throughout the steps of the design. The combination of CFD with response surface methodology can play an important role in such cases. During the conceptual engineering design phase, a quick response is always a matter of urgency. During this phase even a sketch of the geometrical model is rare. Therefore, the utilisation of typical response surface developed for congested and confined environment rather than CFD can be an important tool to help the decision making process, when the geometrical model is not available, provided that similarities can be considered when taking into account the characteristic of the geometry in which the response surface was developed. The present work investigates how three different types of response surfaces behave when predicting overpressure in accidental scenarios based on CFD input. First order, partial second order and complete second order polynomial expressions are investigated. The predicted results are compared with CFD findings for a classical offshore experiment conducted by British Gas on behalf of Mobil and good agreement is observed for higher order response surfaces. The higher order response surface calculations are also compared with CFD calculations for a typical offshore module and good agreement is also observed. 相似文献
22.
Andrade Mariana Carvalho Araujo Nara Santos Vianna Maria Isabel Pereira Cangussu Maria Cristina Teixeira Gomes-Filho Isaac Suzart Ribeiro Daniel Araki Cury Patrícia Ramos dos Santos Jean Nunes 《Environmental science and pollution research international》2021,28(43):60717-60725
Environmental Science and Pollution Research - Studies have shown that domestic waste collectors are exposed to toxicants including infectious pathogens, which may be linked to their oral health... 相似文献
23.
Andressa Cristhy Buch Maria Elizabeth Fernandes Correia Daniel Cabral Teixeira Emmanoel Vieira Silva-Filho 《环境科学学报(英文版)》2015
The increasing levels of mercury (Hg) found in the atmosphere arising from anthropogenic sources, have been the object of great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the atmosphere. The major input of Hg to ecosystems is through atmospheric deposition (wet and dry), being transported in the atmosphere over large distances. The forest biomes are of strong importance in the atmosphere/soil cycling of elemental Hg through foliar uptake and subsequent transference to the soil through litter, playing an important role as sink of this element. Soil microarthropods are keys to understanding the soil ecosystem, and for such purpose were characterized by the soil fauna of two Units of Forest Conservation of the state of the Rio de Janeiro, inwhich one of the areas suffer quite interference from petrochemicals and industrial anthropogenic activities and other area almost exempts of these perturbations. The results showed that soil and litter of the Atlantic Forest in Brazil tend to stock high mercury concentrations, which could affect the abundance and richness of soil fauna, endangering its biodiversity and thereby the functioning of ecosystems. 相似文献
24.
Paranhos Gazineu MH de Araújo AA Brandão YB Hazin CA de O Godoy JM 《Journal of environmental radioactivity》2005,81(1):47-54
Scales and sludge generated during oil extraction and production can contain uranium, thorium, radium and other natural radionuclides, which can cause exposure of maintenance personnel. This work shows how the oil content can influence the results of measurements of radionuclide concentration in scale and sludge. Samples were taken from a PETROBRAS unit in Northeast Brazil. They were collected directly from the inner surface of water pipes or from barrels stored in the waste storage area of the E&P unit. The oil was separated from the solids with a Soxhlet extractor by using aguarras at 90+/-5 degrees C as solvent. Concentrations of 226Ra and 228Ra in the samples were determined before and after oil extraction by using an HPGe gamma spectrometric system. The results showed an increase in the radionuclide concentration in the solid (dry) phase, indicating that the above radionuclides concentrate mostly in the solid material. 相似文献
25.
Rodrigues Izabella Almirante Porto Tiburcio Alves Roberta Vianna Guimarães Maria José de Oliveira Cavalcanti Gomes Thiago Santiago Pacheco Elen Beatriz Acordi Vasques 《Environment, Development and Sustainability》2022,24(8):9705-9730
Environment, Development and Sustainability - This review aimed to analyze plastic lumber manufacturing in Brazil, a country with a large amount of natural wood, and devise strategies to boost... 相似文献
26.
Sávio S.V. Vianna R. Stewart Cant 《Journal of Loss Prevention in the Process Industries》2010,23(1):3-14
The production of oil and gas is an inherently hazardous task. Therefore it is crucial to provide reliable estimates of the risks involved. The major contributors to the risk level of an offshore installation, for example, arise from accidents involving explosion and fire. Computational Fluid Dynamics (CFD) can be a powerful tool to help with the calculation of accidental explosion scenarios. In this context, the present work suggests a novel implementation of a model based on a modified Porosity Distributed Resistance (MPDR) approach within an unstructured 3D Navier–Stokes solver. The model operates by representing parts of the filtered geometry from the original model through porosity values attributed to an unstructured tetrahedral mesh. Extra resistance terms are added in the momentum equation as well as extra sources of turbulence. Two extra sources of turbulence are modelled. The first of these is due to the shear layers of the non-resolved obstacles, whilst the second is due to the presence of wakes behind the non-resolved obstacles. Results for 2D and 3D test cases are compared against both experimental data and simulations with fully-resolved geometry and good agreement is observed. 相似文献
27.
Rosenfelder N Lehnert K Kaffarnik S Torres JP Vianna M Vetter W 《Environmental science and pollution research international》2012,19(2):379-389
Introduction
Five liver samples of two different ray species (Gymnura altavela and Zapteryx brevirostris) off the coast of Rio de Janeiro, Brazil, were analyzed for their pollution with anthropogenic and naturally occurring organohalogen compounds. 相似文献28.
Andressa Gonsioroski Mary Laws Vasiliki E. Mourikes Alison Neff Jenny Drnevich Michael J. Plew Jodi A. Flaws 《环境科学学报(英文版)》2022,34(7):46-57
Iodoacetic acid (IAA) is an unregulated water disinfection byproduct that is an ovarian toxicant. However, the mechanisms of action underlying IAA toxicity in ovarian follicles remain unclear. Thus, we determined whether IAA alters gene expression in ovarian follicles in mice. Adult female mice were dosed with water or IAA (10 or 500 mg/L) in the water for 35-40 days. Antral follicles were collected for RNA-sequencing analysis and sera were collected to measure estradiol. RNA-sequencing analysis identified 1063 differentially expressed genes (DEGs) in the 10 and 500 mg/L IAA groups (false discovery rate FDR < 0.1), respectively, compared to controls. Gene Ontology Enrichment analysis showed that DEGs were involved with RNA processing and regulation of angiogenesis (10 mg/L) and the cell cycle and cell division (500 mg/L). Pathway Enrichment analysis showed that DEGs were involved in the phosphatidylinositol 3-kinase and protein kinase B (PI3K-Akt), gonadotropin-releasing hormone (GnRH), estrogen, and insulin signaling pathways (10 mg/L). Pathway Enrichment analysis showed that DEGs were involved in the oocyte meiosis, GnRH, and oxytocin signaling pathways (500 mg/L). RNA-sequencing analysis identified 809 DEGs when comparing the 500 and 10 mg/L IAA groups (FDR < 0.1). DEGs were related to ribosome, translation, mRNA processing, oxidative phosphorylation, chromosome, cell cycle, cell division, protein folding, and the oxytocin signaling pathway. Moreover, IAA exposure significantly decreased estradiol levels (500 mg/L) compared to control. This study identified key candidate genes and pathways involved in IAA toxicity and can help to further understand the molecular mechanisms of IAA toxicity in ovarian follicles. 相似文献
29.
La Fuente Carla I. A. de Souza Andressa Tamyris Tadini Carmen C. Augusto Pedro Esteves Duarte 《Journal of Polymers and the Environment》2021,29(6):1908-1920
Journal of Polymers and the Environment - In this study cassava starch modified by ozone technology and cellulose nanofibres were used to produce films. These nanocomposites were produced by... 相似文献
30.
Andressa Cristhy Buch Maria Elizabeth Fernandes Correi Daniel Cabral Teixeir Emmanoel Vieira Silva-Filho 《环境科学学报(英文版)》2015,27(6):217-227
The increasing levels of mercury (Hg) found in the atmosphere arising from anthropogenic sources, have been the object of great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the atmosphere. The major input of Hg to ecosystems is through atmospheric deposition (wet and dry), being transported in the atmosphere over large distances. The forest biomes are of strong importance in the atmosphere/soil cycling of elemental Hg through foliar uptake and subsequent transference to the soil through litter, playing an important role as sink of this element. Soil microarthropods are keys to understanding the soil ecosystem, and for such purpose were characterized by the soil fauna of two Units of Forest Conservation of the state of the Rio de Janeiro, inwhich one of the areas suffer quite interference from petrochemicals and industrial anthropogenic activities and other area almost exempts of these perturbations. The results showed that soil and litter of the Atlantic Forest in Brazil tend to stock high mercury concentrations, which could affect the abundance and richness of soil fauna, endangering its biodiversity and thereby the functioning of ecosystems. 相似文献