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1.
Heliyon ; 9(6): e16579, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37332924

RESUMO

A numerical investigation has been carried out in a wavy-shaped enclosure with an elliptical inner cylinder to find out the effect of an inclined magnetic field and a non-Newtonian nanofluid on fluid flow and heat transfer. Here, the dynamic viscosity and thermal conductivity of the nanofluid are also taken into account. These properties change with the temperature and nanoparticle volume fraction. The vertical walls of the enclosure are modeled through complex wavy geometries and are kept at a constant cold temperature. The inner elliptical cylinder is deemed to be heated and the horizontal walls are considered adiabatic. Temperature difference between the wavy walls and the hot cylinder leads to natural convective circulation flow inside the enclosure. The dimensionless set of the governing equations and associated boundary conditions are numerically simulated using the COMSOL Multiphysics software, which is based on finite element methods. Numerical analysis has been scrutinized for varying Rayleigh number (Ra), Hartmann number (Ha), magnetic field inclination angle (γ), rotation angle of the inner cylinder (ω), power-law index (n), and nanoparticle volume fraction (ϕ). The findings demonstrate that the solid volumetric concentration of nanoparticles diminishes the fluid movement at greater values of φ. The heat transfer rate decreases for larger nanoparticle volume fractions. The flow strength increases with an increasing Rayleigh number resulting in a best possible heat transfer. A higher Hartmann number diminishes the fluid flow but converse behavior is exhibited for magnetic field inclination angle (γ). The average Nusselt number (Nuavg) values are maximum for γ = 90°. The power-law index plays a significant role on the heat transfer rate, and results show that the shear-thinning liquid augments the average Nusselt number.

2.
Zhonghua Liu Xing Bing Xue Za Zhi ; 39(9): 1152-1158, 2018 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-30293302

RESUMO

Objective: To study the spatial-temporal dynamical features of hand-foot-mouth disease (HFMD) in Shaanxi Province, so as to provide evidence for the development of relative prevention and control programs on HFMD. Methods: Surveillance data of HFMD was collected from the China Information System for Diseases Control and Prevention from 2009 to 2013. Related data on population and gross domestic product (GDP) was obtained from Shaanxi Statistical Yearbook. Statistical tools as R3.4.1, ArcGIS 10.2 and SaTScan 9.2 software were used to describe the spatial-temporal distribution of the disease. Power-law method on spatial-temporal-multicomponent model was used to analyze the spatial-temporal evolution of the HFMD epidemics in Shaanxi Province. Results: A total of 229 904 cases of HFMD were reported in Shaanxi Province from 2009 to 2013, with an average annual incidence as 122.50 per 100 000. Obvious seasonal characteristics were noticed, with 71.71% of the total cases identified between April and July. Counties with high incidence were mainly distributed in the mid-and east parts of Guanzhong area. Through temporal and spatial scan statistics, we identified that ClassⅠ clustering area was fixed to the central and southeast regions of Shaanxi province which were around Xi'an City between 2009 and 2013, with the relative risk (RR) as 2.24, ranging from 2.18 to 3.08. Results from Power-law analysis showed that the continuous follow-up impact from the previous HFMD epidemics appeared strong in Tongguan, Pucheng districts of Weinan City and Weiyang district of Xi'an, with autoregressive components as 1.14, 0.97 and 0.89, respectively. The risk of HFMD seemed high in Huayin city, Changan and Yanta districts and with the endemic components as 5.08, 4.12 and 4.08, respectively. Impact of the epidemics on nearby districts was largely seen in Lianhu district of Xi'an, Wugong district of Xianyang and Gaoling district of Xi'an with epidemic components as 2.12, 2.08 and 1.77, respectively. The etiological constituents of HFMD were mainly Enterovirus 71 between 2009 and 2012, while HFMD was mainly caused by other entero-viruses, in 2013. Conclusion: Significant spatial-temporal heterogeneity of HFMD was seen in Shaanxi province, which called for specific strategies to be developed in the highly endemic areas.


Assuntos
Análise por Conglomerados , Doença de Mão, Pé e Boca/epidemiologia , Análise Espaço-Temporal , China/epidemiologia , Cidades , Humanos , Incidência , Vigilância em Saúde Pública
3.
Chinese Journal of Epidemiology ; (12): 1152-1158, 2018.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-738115

RESUMO

Objective To study the spatial-temporal dynamical features of hand-foot-mouth disease (HFMD) in Shaanxi Province,so as to provide evidence for the development of relative prevention and control programs on HFMD.Methods Surveillance data of HFMD was collected from the China Information System for Diseases Control and Prevention from 2009 to 2013.Related data on population and gross domestic product (GDP) was obtained from Shaanxi Statistical Yearbook.Statistical tools as R3.4.1,ArcGIS 10.2 and SaTScan 9.2 software were used to describe the spatialtemporal distribution of the disease.Power-law method on spatial-temporal-multicomponent model was used to analyze the spatial-temporal evolution of the HFMD epidemics in Shaanxi Province.Results A total of 229 904 cases of HFMD were reported in Shaanxi Province from 2009 to 2013,with an average annual incidence as 122.50 per 100 000.Obvious seasonal characteristics were noticed,with 71.71% of the total cases identified between April and July.Counties with high incidence were mainly distributed in the mid-and east parts of Guanzhong area.Through temporal and spatial scan statistics,we identified that Class Ⅰ clustering area was fixed to the central and southeast regions of Shaanxi province which were around Xi'an City between 2009 and 2013,with the relative risk (RR)as 2.24,ranging from 2.18 to 3.08.Results from Power-law analysis showed that the continuous follow-up impact from the previous HFMD epidemics appeared strong in Tongguan,Pucheng districts of Weinan City and Weiyang district of Xi'an,with autoregressive components as 1.14,0.97 and 0.89,respectively.The risk of HFMD seemed high in Huayin city,Changan and Yanta districts and with the endemic components as 5.08,4.12 and 4.08,respectively.Impact of the epidemics on nearby districts was largely seen in Lianhu district of Xi'an,Wugong district of Xianyang and Gaoling district of Xi'an with epidemic components as 2.12,2.08 and 1.77,respectively.The etiological constituents of HFMD were mainly Enterovirus 71 between 2009 and 2012,while HFMD was mainly caused by other entero-viruses,in 2013.Conclusion Significant spatial-temporal heterogeneity of HFMD was seen in Shaanxi province,which called for specific strategies to be developed in the highly endemic areas.

4.
Chinese Journal of Epidemiology ; (12): 1152-1158, 2018.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-736647

RESUMO

Objective To study the spatial-temporal dynamical features of hand-foot-mouth disease (HFMD) in Shaanxi Province,so as to provide evidence for the development of relative prevention and control programs on HFMD.Methods Surveillance data of HFMD was collected from the China Information System for Diseases Control and Prevention from 2009 to 2013.Related data on population and gross domestic product (GDP) was obtained from Shaanxi Statistical Yearbook.Statistical tools as R3.4.1,ArcGIS 10.2 and SaTScan 9.2 software were used to describe the spatialtemporal distribution of the disease.Power-law method on spatial-temporal-multicomponent model was used to analyze the spatial-temporal evolution of the HFMD epidemics in Shaanxi Province.Results A total of 229 904 cases of HFMD were reported in Shaanxi Province from 2009 to 2013,with an average annual incidence as 122.50 per 100 000.Obvious seasonal characteristics were noticed,with 71.71% of the total cases identified between April and July.Counties with high incidence were mainly distributed in the mid-and east parts of Guanzhong area.Through temporal and spatial scan statistics,we identified that Class Ⅰ clustering area was fixed to the central and southeast regions of Shaanxi province which were around Xi'an City between 2009 and 2013,with the relative risk (RR)as 2.24,ranging from 2.18 to 3.08.Results from Power-law analysis showed that the continuous follow-up impact from the previous HFMD epidemics appeared strong in Tongguan,Pucheng districts of Weinan City and Weiyang district of Xi'an,with autoregressive components as 1.14,0.97 and 0.89,respectively.The risk of HFMD seemed high in Huayin city,Changan and Yanta districts and with the endemic components as 5.08,4.12 and 4.08,respectively.Impact of the epidemics on nearby districts was largely seen in Lianhu district of Xi'an,Wugong district of Xianyang and Gaoling district of Xi'an with epidemic components as 2.12,2.08 and 1.77,respectively.The etiological constituents of HFMD were mainly Enterovirus 71 between 2009 and 2012,while HFMD was mainly caused by other entero-viruses,in 2013.Conclusion Significant spatial-temporal heterogeneity of HFMD was seen in Shaanxi province,which called for specific strategies to be developed in the highly endemic areas.

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