检索结果-南通市图书馆

Modeling uncertainties of reservoir flushing simulations

International Journal of Sediment Research 2023年第5期38卷 698-710页

作者： Camila Bergmann Goulart Tobias Bleninger hugo de oliveira fagundes Fernando Mainardi Fan department of Environmental Engineering Federal University of Parana Institute of Hydraulic Research Federal University of Rio Grande do Sul

Every dam or barrage construction affects the watercourse and the retention of sediment that previously was carried by the river, which can lead to siltation of the reservoir and obstruction of water intakes over time, reducing their capacities. However, the information available regarding the effect of sediment and drawdown parameters, sediment management at reservoirs, as well as different equational approaches,is scarce. The current research aims to evaluate the effect of parameters associated with numerical modeling of sediment management in reservoirs considering scenarios with different drawdowns,transport equations, sediment size distributions, and thickness of the initial sediment layer. The case study of the Aimore s Hydropower Plant(HPP) is used, applying the delft3D-FLOW model for twodimensional modeling. All parameters influenced the volume of mobilized sediment, among which the initial layer thickness was the parameter that resulted in the greatest changes in simulated results. In general, the results show that the uncertainties in the input parameters outweigh the uncertainties between the techniques, which found large variations in results when evaluating the use of different transport equations. These results indicate the importance of proper estimation of model parameters for predicting effects with accuracy and the need for such studies before planning and management operations are evaluated to avoid environmental harm and energy waste.

关键词： Reservoir sedimentation Sediment transport modeling Flushing Sediment management

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Feasibility of performing the 3-minute step test with remote supervision in children and adolescents with cystic fibrosis: A comparative study

引用

Pediatric Investigation 2024年第2期8卷 83-90页

作者： Fernanda Maria Vendrusculo Gisele Apolinario da Costa Maria Amelia Bagatini Brenda Maria Henrique Maia Lemes Carolina Aguiar Faria Larissa Carvalhaes de oliveira Evanirso da Silva Aquino Marcio Vinicius fagundes Donadio Laboratory of Pediatric Physical Activity Infant CenterPontificia Universidade Catolica do Rio Grande do Sul(PUCRS)Porto AlegreBrazil Hospital Infantil Joao Paulo II-Fundacao Hospitalar do Estado de Minas Gerais(FHEMIG) Belo HorizonteBrazil departament of Physiotherapy Pontificia Universidade Catolica de Minas Gerais(PUCMG)-Campus BetimBetimBrazil department of Physiotherapy Faculty of Medicine and Health SciencesUniversitat Internacional de Catalunya(UIC)BarcelonaSpain

Importance:The 3-min step test is a simple option to monitor submaximal exercise capacity,although its use via remote video monitoring has not been investigated in children with cystic fibrosis(CF).Objective:This study aimed to assess the feasibility and reproducibility of performing the 3-min step test with remote ***:A cross-sectional study including CF patients(6-18 years)from two CF services were ***,anthropometric,clinical,and lung function data were collected and two 3-min step tests were performed:(i)in-person supervision,and(ii)remotely supervised by video *** and after the tests,heart rate(HR),oxygen saturation(SpO_(2)),and the Borg score for dyspnea and lower limb fatigue were ***:Twenty-three patients(10.7±3.7 years)with a mean FEV1 of 89.5%±23.2%were *** were no significant differences between tests,with mean differences(95%confidence intervals)in final HR of-3.3(-8.9,2.4),change in HR of-1.9(-6.1,2.1),final SpO_(2) of 0.3(-0.4,1.0),and final dyspnea of 0.1(-0.8,0.9).The intraclass correlation coefficient was 0.852(final HR),0.762(final SpO_(2)),and 0.775(final lower limb fatigue).Significant and moderate correlations were found between tests for final HR(r=0.75),change in HR(r=0.61),and final SpO_(2)(r=0.61).The Bland-Altman analysis showed a mean difference in final SpO_(2) between tests of 0.3%(limit of agreement-3.0%,3.5%).Interpretation:Physiological responses between tests were similar,indicating it was feasible to perform the 3-min step test with remote supervision in CF children.

关键词： Children Cystic fibrosis Exercise test Telehealth

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stepped machine learning for the development of mineral models: Concepts and applications in the pre-salt reservoir carbonate rocks

引用

能源与人工智能(英文) 2021年第1期3卷 167-179页

作者： Lucas Abreu Blanes de oliveira Luiz Felipe Niedermaier Custodio Thais Bortotti fagundes Carina Ulsen Cleyton de Carvalho Carneiro Petrobras–Petroleo Brasileiro S.A. Avenida Henrique Valadares 28CentroRio de Janeiro20231-030 Rio de JaneiroBrazil Universidade de Sao Paulo USPEscola PolitecnicaPraça Narciso de AndradeVila MathiasSantosSão Paulo 11013-560Brazil

Understanding rock mineralogy is essential for formation evaluation,improving the calculation of porosity and hydrocarbon *** primary method to obtain the mineralogy from a well is by applying a model to the geochemical tool’s chemical ***,creating a mineralogical model presents challenges such as the minerals’chemical composition and the decision to include a mineral in the *** traditional application of machine learning can make mineral models less realistic since conventional training is developed based on a set of minerals with different occurrences,lowering some minerals’*** present research proposes the stepped machine learning(SML),a stepped way to use machine learning to create a mineralogical model from chemical and mineralogical data.A database was assembled with the elemental concentration obtained with XRF analyses and the mineral concentrations obtained with XRD *** chemical elements were Al,Ca,Fe,K,Mg,Mn,Na,Si,and *** minerals were calcite,dolomite,quartz,clays,K-feldspar,plagioclase,and *** algorithms were tested:MLP,GAN,Random Forest,and XGBoost,with XGBoost showing the best *** was applied,where a mineral model results are used to train a subsequent *** allowed for a significant improvement in some models,notably to clays with an increase in R 2 from 0.597 to 0.853,quartz an increase from 0.673 to 0.869,and calcite,from 0.758 to 0.862.A decrease in the mean squared error of these minerals’models was also *** model was applied to the geochemical logs from three wells drilled in the Brazilian pre-salt,and the results were compared with XRD *** SML model was able to honor the mineral concentrations for different *** is demonstrated that the integration between machine learning tools and geological knowledge in SML was crucial for creating a representative mineralogical model.

关键词： minerals quartz reservoir

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：