Passive smoking in the workplace : selected issues /

"May 1986."

Democratization in a passive dendritic tree: an analytical investigation

One way to achieve amplification of distal synaptic inputs on a dendritic tree is to scale the amplitude and/or duration of the synaptic conductance with its distance from the soma. This is an example of what is often referred to as “dendritic democracy”. Although well studied experimentally, to date this phenomenon has not been thoroughly explored from a mathematical perspective. In this paper we adopt a passive model of a dendritic tree with distributed excitatory synaptic conductances and analyze a number of key measures of democracy. In particular, via moment methods we derive laws for the transport, from synapse to soma, of strength, characteristic time, and dispersion. These laws lead immediately to synaptic scalings that overcome attenuation with distance. We follow this with a Neumann approximation of Green’s representation that readily produces the synaptic scaling that democratizes the peak somatic voltage response. Results are obtained for both idealized geometries and for the more realistic geometry of a rat CA1 pyramidal cell. For each measure of democratization we produce and contrast the synaptic scaling associated with treating the synapse as either a conductance change or a current injection. We find that our respective scalings agree up to a critical distance from the soma and we reveal how this critical distance decreases with decreasing branch radius.

Modelagem da propagação sonora em dutos : abordagem matemática no domínio da frequência e do tempo utilizando transformada de laplace

Dissertação (mestrado)—Universidade de Brasília, Faculdade UnB Gama, Faculdade de Tecnologia, Programa de Pós-graduação em Integridade de Materiais da Engenharia, 2016.

Fortress Monroe, Old Point Comfort, and Hygeia Hotel, Va. /

"Entered according to Act of Congress in the year 1861 by E. Sachse & Co. in the Clerks Office of the District Court of Maryland."

Fluidic flow delay by ionogel passive pumps in microfluidic paper-based analytical devices

[EN] A new concept for fluid flow manipulation in microfluidic paper-based analytical devices (m-PADs) is presented by introducing ionogel materials as passive pumps. m-PADs were fabricated using a new doubleside contact stamping process and ionogels were precisely photopolymerised at the inlet of the m-PADs.The ionogels remain mainly on the surface of the paper and get absorbed in the superficial paper-fibers allowing for the liquid to flow from the ionogel into the paper easily. As a proof of concept the fluid flowand mixing behaviour of two different ionogels mPADs were compared with the non-treated mPADs.It was demonstrated that both ionogels highly affect the fluid flow by delaying the flow due to their different physical and chemical properties and water holding capacities.

Active versus passive management : the case of BOVESPA

Mestrado em Finanças

Subjective comparison of consumer television technologies for 3D visualization

This paper presents a comparison among different consumer 3D display technologies by means of a subjective assessment test. Therefore, four 55-in displays have been considered: one autostereoscopic display, one stereoscopic with polarized passive glasses, and two with active shutter glasses. In addition, a high-quality 3D video database has been used to show diverse material with both views in high definition. To carry out the test, standard recommendations have been followed considering also some modifications looking for a test environment more similar to real home viewing conditions, with the objective of obtaining more representative conclusions. Moreover, several perceptual factors have been considered to study the performance of the displays, such as picture quality, depth perception, and visual discomfort. The obtained results show interesting issues, like the performance improvement of active shutter glasses technology, the high performance of the polarized glasses technology in terms of quality and comfort, and the need of improvement of the autostereoscopic displays to complement the visual comfort to reach a global high-quality visual experience.

Análise de métodos para aplicação de ventilação natural em projetos de edificações em Natal-RN

Natural ventilation is an efficient bioclimatic strategy, one that provides thermal comfort, healthful and cooling to the edification. However, the disregard for quality environment, the uncertainties involved in the phenomenon and the popularization of artificial climate systems are held as an excuse for those who neglect the benefits of passive cooling. The unfamiliarity with the concept may be lessened if ventilation is observed in every step of the project, especially in the initial phase in which decisions bear a great impact in the construction process. The tools available in order to quantify the impact of projected decisions consist basically of the renovation rate calculations or computer simulations of fluids, commonly dubbed CFD, which stands for Computational Fluid Dynamics , both somewhat apart from the project s execution and unable to adapt for use in parametric studies. Thus, we chose to verify, through computer simulation, the representativeness of the results with a method of simplified air reconditioning rate calculation, as well as making it more compatible with the questions relevant to the first phases of the project s process. The case object consists of a model resulting from the recommendations of the Código de Obras de Natal/ RN, customized according to the NBR 15220. The study has shown the complexity in aggregating a CFD tool to the process and the need for a method capable of generating data at the compatible rate to the flow of ideas and are discarded during the project s development. At the end of our study, we discuss the necessary concessions for the realization of simulations, the applicability and the limitations of both the tools used and the method adopted, as well as the representativeness of the results obtained

Análise de componentes arquitetônicos para potencialização da ventilação natural com ênfase em captadores de vento

The building envelope is the principal mean of interaction between indoors and environment, with direct influence on thermal and energy performance of the building. By intervening in the envelope, with the proposal of specific architectural elements, it is possible to promote the use of passive strategies of conditioning, such as natural ventilation. The cross ventilation is recommended by the NBR 15220-3 as the bioclimatic main strategy for the hot and humid climate of Natal/RN, offering among other benefits, the thermal comfort of occupants. The analysis tools of natural ventilation, on the other hand, cover a variety of techniques, from the simplified calculation methods to computer fluid dynamics, whose limitations are discussed in several papers, but without detailing the problems encountered. In this sense, the present study aims to evaluate the potential of wind catchers, envelope elements used to increase natural ventilation in the building, through CFD simplified simulation. Moreover, it seeks to quantify the limitations encountered during the analysis. For this, the procedure adopted to evaluate the elements implementation and efficiency was the CFD simulation, abbreviation for Computer Fluid Dynamics, with the software DesignBuilder CFD. It was defined a base case, where wind catchers were added with various settings, to compare them with each other and appreciate the differences in flows and air speeds encountered. Initially there has been done sensitivity tests for familiarization with the software and observe simulation patterns, mapping the settings used and simulation time for each case simulated. The results show the limitations encountered during the simulation process, as well as an overview of the efficiency and potential of wind catchers, with the increase of ventilation with the use of catchers, differences in air flow patterns and significant increase in air speeds indoors, besides changes found due to different element geometries. It is considered that the software used can help designers during preliminary analysis in the early stages of design

Fachada flexível para casa padronizada em condomínios

The employment of flexibility in the design of façades makes them adaptable to adverse weather conditions, resulting in both minimization of environmental discomfort and improvement of energy efficiency. The present study highlights the potential of flexible façades as a resource to reduce rigidity and form repetition, which are usually employed in condominiums of standardized houses; as such, the work presented herein contributes to field of study of architectural projects strategies for adapting and integrating buildings within the local climate context. Two façade options were designed using as reference the bionics and the kinetics, as well as their applications to architectural constructions. This resulted in two lightweight and dynamic structures, which cater to constraints of comfort through combinations of movements, which control the impact of solar radiation and of cooling in the environment. The efficacy and technical functionality of the façades were tested with comfort analysis and graphic computation software, as well as with physical models. Thus, the current research contributes to the improvement of architectural solutions aimed at using passive energy strategies in order to offer both better quality for the users and for the sustainability of the planet

Evaluation of the Effect of Passive Smoking on Lactoferrin and AST on 12 - 15 Years Old Children and Adolescents

Background: Passive smokers are involuntarily exposed to cigarette or tobacco smoke and as known, inhalation of environmental tobacco smoke is a serious threat. There is little information about the effect of passive smoking on salivary markers and periodontal indices. Objectives: This study investigated the effect of passive smoking on lactoferrin and AST in 12 - 15 years old children and adolescents. Patients and Methods: This case-control analytic correlation type study with no-convenience random sampling method was performed on 160 children aged 12 - 15 who had smokers in their families. The eligible children were divided into two equal groups; 80 cot+ children as case group and 80 cot– children as control group, matched according to age, sex and plaque index. Plaque index was obtained from all subjects. 2 cc unstimulated salivary samples were collected by spitting method. The collected specimens were tested by lactoferrin and AST kits in biochemistry were measured on the day of sampling laboratory. Gingival index Loe and Silness (GI) and Probing Pocket Depth (PPD). Results: Mean and Standard Deviation of PPD and GI was 2.01 ± 0.077 and 1.53 ± 0.055 in experimental group and 1.93 ± 0.073 and 1.49 ± 0.046 in control group respectively (P < 0.001). The Mean and Standard Deviation parameters of lactoferrin and AST, in the experimental group was 38.66 ± 25.15 and 13.45 ± 6.33 and in the control group 10.18 ± 6.82 and 6.53 ± 2.65 group, respectively (P < 0.001). Conclusions: Passive smoking can be effective on inflammatory process of periodontal and salivary biomarkers related to inflammation. Lactoferrin was 11 - 104 in case group and 0.5 - 38 in control group. Aspartat aminotransferase in case group was 2.64 - 30.43 and in control group it was 2.16 - 12.02.

Simulação computacional como ferramenta de auxílio ao projeto: aplicação em edifícios naturalmente ventilados no clima de Natal/RN

Natural air ventilation is the most import passive strategy to provide thermal comfort in hot and humid climates and a significant low energy strategy. However, the natural ventilated building requires more attention with the architectural design than a conventional building with air conditioning systems, and the results are less reliable. Therefore, this thesis focuses on softwares and methods to predict the natural ventilation performance from the point of view of the architect, with limited resource and knowledge of fluid mechanics. A typical prefabricated building was modelled due to its simplified geometry, low cost and occurrence at the local campus. Firstly, the study emphasized the use of computational fluid dynamics (CFD) software, to simulate the air flow outside and inside the building. A series of approaches were developed to make the simulations possible, compromising the results fidelity. Secondly, the results of CFD simulations were used as the input of an energy tool, to simulate the thermal performance under different rates of air renew. Thirdly, the results of temperature were assessed in terms of thermal comfort. Complementary simulations were carried out to detail the analyses. The results show the potentialities of these tools. However the discussions concerning the simplifications of the approaches, the limitations of the tools and the level of knowledge of the average architect are the major contribution of this study