Contact angle dependence on the fluid-wall dispersive energy

Vapor-liquid menisci of the truncated and shifted Lennard-Jones fluid between parallel planar walls are investigated by molecular dynamics simulation. Thereby, the characteristic energy of the unlike dispersive interaction between fluid molecules and wall atoms is systematically varied to determine its influence on the contact angle. The temperature is varied as well, covering most of the range between the triple point temperature and the critical temperature of the bulk fluid. The transition between obtuse and acute angles is found to occur at a temperature-independent magnitude of the fluid-wall dispersive interaction energy. On the basis of the present simulation results, fluid-wall interaction potentials can be adjusted to contact angle measurements

Gestão estratégica: proposta de um modelo para a Agro Veterinária Timbó

TCC (graduação) - Universidade Federal de Santa Catarina, Centro Sócio Econômico, Curso de Administração.Este trabalho tem como objetivo estabelecer um modelo de gestão estratégica que contemple mecanismos de concepção, implementação e gerenciamento continuo da estratégia da Agro Veterinária Timbó, empresa em familiar do ramo de comércio varejista e atacadista de produtos agropecuários em geral, atuante no mercado de animais de companhia e de produção, a partir do ano de 2006. A justificativa para a realização do estudo se deu principalmente pela utilidade do modelo para posterior aplicação na empresa. No que se refere a metodologia o estudo se caracteriza como tendo fins exploratórios e descritivos, e sendo um estudo de caso. A fundamentação teórica reuniu principais pensamentos a cerca da estratégia e algumas metodologias de planejamento. As análises provenientes do estudo da situação do diagnóstico estratégico da Agro Veterinária Timbó serviram como base para que a empresa pudesse estabelecer um foco estratégico e as diretrizes que guiaram a estruturação do modelo de gestão estratégica. A orientação estratégica adotada pela empresa atualmente é baseada no empreendedorismo de seu fundador, porém o recente crescimento estimulou a discussão de deficiências e mudanças para adequação da empresa. 0 modelo de gestão estratégica teve inspiração no Balanced Scorecard e o gerenciamento pelas diretrizes, e muitas de suas ferramentas foram adaptadas para compor as suas três fases, sendo estas o planejamento de longo e de curto prazo, e a avaliação continuada e controle. Este modelo visa estimular o pensamento estratégico na direção de empresa, assim como também fornecer ferramentas que auxiliem a tradução destas estratégias em um processo continuo no dia-a-dia da empresa

A quasi-dimensional model of turbulence and global charge motion for spark ignition engines with fully variable valvetrains

In this article, a new in-cylinder turbulence modeling approach aims at the improvement of quasi-dimensional simulations for modern spark ignition engines with fully variable valvetrains. Within the derived quasi-dimensional turbulence model, the turbulent production term can physically react on a change of engine operation (e.g. intake valve lift, intake valve timing, engine speed and boost pressure). Moreover, the approach offers access to detailed charge motion quantities for the first time in quasi-dimensional calculations. Hence, it is able to satisfy qualitative and quantitative turbulence descriptions within the entire operating range of the engine

Application of Proper Orthogonal Decomposition Methods in Reactive Pore Diffusion Simulations

Reactive pore diffusion is an important process in automotive exhaust-gas aftertreatment modelling the overall conversion of pollutants. It features highly nonlinear source terms from chemical reactions coupled with transport processes. This work examines the application of model reduction by proper orthogonal decomposition. It is shown that this technique can be successfully applied to the system using separate bases for each species. Using a basis obtained for baseline conditions, predictions can be made for species profiles within a pore system for different conditions, potentially leading to significantly reduced computational requirements

Urban Climate Under Change [UC]2 – A National Research Programme for Developing a Building-Resolving Atmospheric Model for Entire City Regions

Large cities and urban regions are confronted with rising pressure by environmental pollution, impacts of climate change, as well as natural and health hazards. They are characterised by heterogeneous mosaics of urban structures, causing modifications of atmospheric processes on different temporal and spatial scales. Planning authorities need reliable, locally relevant information on urban atmospheric processes, providing fine spatial resolutions in city quarters or street canyons, as well as projections of future climates, specifically downscaled to individual cities. Therefore, building-resolving urban climate models for entire city regions are required as tool for urban development and planning, air quality control, as well as for design of actions for climate change mitigation and adaptation. To date, building-resolving atmospheric models covering entire large cities are mostly missing. The German research programme “Urban Climate Under Change” ([UC]2) aims at developing a new urban climate model, to acquire three-dimensional observational data for model testing and validation, and to test its practicability and usability in collaboration with relevant stakeholders to provide a scientifically sound and practicable instrument to address the above mentioned challenges. This article provides an outline of the collaborative activities of the [UC]2 research programme

Vector Flow Imaging Compared with Conventional Doppler Ultrasound and Thermodilution for Estimation of Blood Flow in the Ascending Aorta

Transverse oscillation (TO) is a real-time ultrasound vector flow method implemented on a commercial scanner. The TO setup was examined on a flowrig with constant and pulsatile flow. Subsequently, 25 patients undergoing cardiac bypass surgery were scanned intraoperatively with TO on the ascending aorta and compared to transesophageal echocardiography (TEE) and pulmonary artery catheter thermodilution (PACTD). On the flowrig, TO had a precision of 5.5%, 9.4% and 14.7%, a percentage error of 18.2%, 14.6% and 40.7%, and a mean bias of 0.4 cm/s, 36.8 ml/min and 32.4 ml/min for velocity and flow rate (constant and pulsatile) estimation. The correlation coefficients for all flowrig evaluations were 0.99 indicating systematic bias. After bias correction, the percentage error was reduced to 11.5%, 12.6% and 15.9% for velocity and flow rate (constant and pulsatile) estimation. In the in vivo setup, TO, TEE, and PACTD had a precision of 21.9%, 13.7%, and 12.0%. TO compared with TEE and PACTD had a mean bias of 12.6 cm/s and −0.08 l/min, and a percentage error of 23.4%, and 36.7%, respectively. The percentage error was reduced to 22.9% for the TEE comparison, but increased to 43.8% for the PACTD comparison, after correction for the systematic bias found in the flowrig. TO is a reliable and precise method for velocity and flow rate estimation on a flowrig. However, TO with the present setup, is not interchangeable with PACTD for cardiac volume flow estimation, but is a reliable and precise angle-independent ultrasound alternative for velocity estimation of cardiac flow. </jats:p