210 research outputs found
A New Method to Simulate Free Surface Flows for Viscoelastic Fluid
Free surface flows arise in a variety of engineering applications. To predict the dynamic characteristics of such problems, specific numerical methods are required to accurately capture the shape of free surface. This paper proposed a new method which combined the Arbitrary Lagrangian-Eulerian (ALE) technique with the Finite Volume Method (FVM) to simulate the time-dependent viscoelastic free surface flows. Based on an open source CFD toolbox called OpenFOAM, we designed an ALE-FVM free surface simulation platform. In the meantime, the die-swell flow had been investigated with our proposed platform to make a further analysis of free surface phenomenon. The results validated the correctness and effectiveness of the proposed method for free surface simulation in both Newtonian fluid and viscoelastic fluid
Comparison of Microbial Community Compositions of Injection and Production Well Samples in a Long-Term Water-Flooded Petroleum Reservoir
Water flooding plays an important role in recovering oil from depleted petroleum reservoirs. Exactly how the microbial communities of production wells are affected by microorganisms introduced with injected water has previously not been adequately studied. Using denaturing gradient gel electrophoresis (DGGE) approach and 16S rRNA gene clone library analysis, the comparison of microbial communities is carried out between one injection water and two production waters collected from a working block of the water-flooded Gudao petroleum reservoir located in the Yellow River Delta. DGGE fingerprints showed that the similarities of the bacterial communities between the injection water and production waters were lower than between the two production waters. It was also observed that the archaeal composition among these three samples showed no significant difference. Analysis of the 16S rRNA gene clone libraries showed that the dominant groups within the injection water were Betaproteobacteria, Gammaproteobacteria and Methanomicrobia, while the dominant groups in the production waters were Gammaproteobacteria and Methanobacteria. Only 2 out of 54 bacterial operational taxonomic units (OTUs) and 5 out of 17 archaeal OTUs in the injection water were detected in the production waters, indicating that most of the microorganisms introduced by the injection water may not survive to be detected in the production waters. Additionally, there were 55.6% and 82.6% unique OTUs in the two production waters respectively, suggesting that each production well has its specific microbial composition, despite both wells being flooded with the same injection water
Brilliant circularly polarized -ray sources via single-shot laser plasma interaction
Circularly polarized (CP) -ray sources are versatile for broad
applications in nuclear physics, high-energy physics and astrophysics. The
laser-plasma based particle accelerators provide accessibility for much higher
flux -ray sources than conventional approaches, in which, however, the
circular polarization properties of emitted -photons are used to be
neglected. In this letter, we show that brilliant CP -ray beams can be
generated via the combination of laser plasma wakefield acceleration and plasma
mirror techniques. In weakly nonlinear Compton scattering scheme with moderate
laser intensities, the helicity of the driving laser can be transferred to the
emitted -photons, and their average polarization degree can reach about
() with a peak brilliance of photons/(s
mm mrad 0.1% BW) around 1~MeV (100~MeV). Moreover,
our proposed method is easily feasible and robust with respect to the laser and
plasma parameters
Expression of Human Granulocyte-Macrophage Colony-Stimulating Factor in Stably-Transformed BmN and Sf-9 Cells and Silkworms by a Non-Transposon Vector
TesisEsta tesis se titula "Cambio de ruta de transporte del mineral para mejorar la producción en la mina Catalina Huanca Sociedad Minera S.A.C", y tiene como objetivo la factibilidad de la reducción de los costos operativos en la empresa minera, aplicando para ello estándares óptimos de trabajo en el sistema de transporte que se realiza, mejorando de esta manera todo el ciclo de minado, éxito que se logra con un sistema de control y medición exhaustiva de la operación de transporte y que se sintetizan en la supervisión y capacitación continua en lo concerniente a la aplicación de estándares óptimos de trabajo en la operación. El desarrollo inicial de este trabajo expone un seguimiento al actual sistema de transporte que se realiza en la unidad minera, se analizarán los factores que afectan la productividad de la operación de transporte, los métodos de trabajo, y los sistemas de control, a este análisis acompañaremos una propuesta de solución a la actividad que genera un mayor tiempo improductivo en el proceso, obteniéndose un diagnóstico de la situación operacional mediante la supervisión y colaboradores de la empresa minera. La siguiente etapa consiste en la construcción de la rampa Saynocca para cambiar la ruta de transporte de mineral, el cual cambiará la ruta de transporte para mejorar la producción de la unidad minera Catalina Huanca S.A.C. Finalmente se exponen los beneficios que se obtienen con la nueva ruta de transporte reduciendo principalmente la distancia de transporte con una longitud de 16.46 Km a una de 5.8 Km, lo cual significa una reducción considerable del 64.76%, con ello optimizando todo el sistema de transporte de mineral, teniendo como beneficio un ahorro de 119,785.14$ mensual por el transporte de mineral
A genome-wide association study identifies a genomic region for the polycerate phenotype in sheep (Ovis aries)
201
Coupling Strategies Investigation of Hybrid Atomistic-Continuum Method Based on State Variable Coupling
Expression of Human Granulocyte-Macrophage Colony-Stimulating Factor in Stably-Transformed BmN and Sf-9 Cells and Silkworms by a Non-Transposon Vector
Dust aerosol optical depth retrieval and dust storm detection for Xinjiang Region using Indian National Satellite Observations
The Xinjiang Uyghur Autonomous Region (Xinjiang) is located near the western border of China. Xinjiang has a high frequency of dust storms, especially in late winter and early spring. Geostationary satellite remote sensing offers an ideal way to monitor the regional distribution and intensity of dust storms, which can impact the regional climate. In this study observations from the Indian National Satellite (INSAT) 3D are used for dust storm detection in Xinjiang because of the frequent 30-min observations with six bands. An analysis of the optical properties of dust and its quantitative relationship with dust storms in Xinjiang is presented for dust events in April 2014. The Aerosol Optical Depth (AOD) derived using six predefined aerosol types shows great potential to identify dust events. Cross validation between INSAT-3D retrieved AOD and MODIS AOD shows a high coefficient of determination (R2 = 0.92). Ground validation using AERONET (Aerosol Robotic Network) AOD also shows a good correlation with R2 of 0.77. We combined the apparent reflectance (top-of-atmospheric reflectance) of visible and shortwave infrared bands, brightness temperature of infrared bands and retrieved AOD into a new Enhanced Dust Index (EDI). EDI reveals not only dust extent but also the intensity. EDI performed very well in measuring the intensity of dust storms between 22 and 24 April 2014. A visual comparison between EDI and Feng Yun-2E (FY-2E) Infrared Difference Dust Index (IDDI) also shows a high level of similarity. A good linear correlation (R2 of 0.78) between EDI and visibility on the ground demonstrates good performance of EDI in estimating dust intensity. A simple threshold method was found to have a good performance in delineating the extent of the dust plumes but inadequate for providing information on dust plume intensity
First genotyping of Blastocystis in yaks from Qinghai Province, northwestern China.
peer reviewed[en] BACKGROUND: Blastocystis is a common protist that can infect domestic and wild animals worldwide. Yak (Bos grunniens), an ancient species which can survive in alpine regions, has supplied necessities to local residents in plateau areas for generations. However, the infections with Blastocystis in yaks has been ignored for a long time. In the present study, the infections and genotypes of Blastocystis spp. in domestic yaks from Qinghai Province (northwestern China) were explored.
RESULTS: Of 1027 faecal samples collected from yaks in seven regions of Qinghai Province, northwestern China, the total prevalence of Blastocystis was 27.07% (278/1027) targeting the small subunit ribosome rRNA (SSU rRNA) gene. This protist was detected in yaks within each examined age group, geographical origin and season. Significant difference in prevalence was found in yaks from different geographical origins. The highest prevalence (48.94%) was observed in animals from Haixi county. Sequence analysis revealed three animal-specific subtypes (ST10, ST12 and ST14) of Blastocystis spp. in these yaks, with ST10 being the predominant subtype widely distributed in all investigated regions, seasons and age groups. Interestingly, this is the first report about subtype ST12 infecting yaks.
CONCLUSIONS: To our knowledge, this is the first systematic report on Blastocystis prevalence in yaks from China, and the findings provide fundamental data for establishing effective control measures for this protist in yaks as well as other animals in China
- …