The diploma thesis deals with the experimental study of shielding effect of oxide isolating layer on surface potential measured by Kelvin Probe Force Microscopy. For the study of surface potential were created Au/SiO2 based nanostructures by Electron Beam Lithography, Atomic Layer Deposition and Multilayer Deposition. Surface potential was measured depending on the relative humidity and thickness of oxide isolating layer.

Influenza causes substantial morbidity and mortality yearly in both temperate and tropical regions, as well as sporadic and potentially severe pandemics. Although vaccines for seasonal influenza exist, most options for controlling influenza outbreaks are reactive in nature. Sufficiently accurate and well-calibrated forecasts, on the other hand, could allow public health practitioners, medical professionals, and the public to respond to unfolding influenza outbreaks proactively. For example, hospitals could prepare additional beds for a predicted surge, and public health experts could redouble vaccination efforts. Recently, skillful forecasts have been developed for a range of infectious diseases, including influenza, but this work has been limited to only a few countries. In this dissertation, we explore the potential for generating accurate influenza forecasts using a publicly-available dataset of country-level epidemiologic and virologic surveillance data. In Chapter 2, we use a combined model-inference system to generate retrospective forecasts for 64 countries in both temperate and tropical climates. We show that forecast accuracy is significantly better in countries with temperate climates, and that inclusion of environmental forcing, specifically modulation of viral transmissibility due to variability of absolute humidity conditions, also improves forecast accuracy in temperate climates. In Chapter 3, we develop a metapopulation model of twelve European countries using data on international air travel and commuting. We find that this model is unable to produce more skillful forecasts than those produced for individual countries in isolation. We make recommendations for improvements in data collection and reporting that may increase the success of similar modeling efforts in the future. In Chapter 4, we assess the performance of real-time forecasts generated for 37 countries over two influenza seasons and discuss the potential for their use in public health decision making. Finally, in Chapter 5 we describe the results of a small survey of public health practitioners in the United States. We find that the majority of respondents desire more effective communication between modelers and public health practitioners, and we discuss the importance of regular and improved communication in advancing the practical use of forecasts as public health decision making tools. This dissertation advances the science of influenza forecasting by demonstrating that skillful retrospective and real-time forecasts can be generated for many countries where previous forecasting efforts are either minimal or absent. However, it is vital that data quality issues be addressed if further progress is to be made. Future work should focus in particular on climatic drivers of influenza in the tropics and subtropics, on the role of human travel at various spatial scales, and on the development of regional and local forecasting capacity. Additionally, dedicated collaboration between modelers and public health practitioners will be instrumental for motivating and informing the use of forecasts in combating influenza outbreaks.

Certain 30mm munitions used in various military applications are configured with a glass-reinforced nylon band that acts as a firing ring or rotating band. The purpose of this research is to investigate whether storage environments compromise the strength and integrity of the glass-reinforced nylon rotating bands by researching the environmental factors that will degrade nylon and by performing tests to investigate if these factors will embrittle nylon composites. Moisture and temperature are found to be the environmental factors that will have an effect on the rotating bands in their respective storage environments. Absorbed moisture is found to increase the impact strength of nylon while at the same time expanding surface defects and attacking fiber/matrix bonds. Two impact tests using a Tinius Olsen impact tester are used to determine the effects of different storage environments on the impact strength of neat resin nylon 6/12 and 33% glass-reinforced nylon 6/12. The relative Shore D hardness of each reinforced sample is also measured to determine if any correlation between impact strength and hardness exists. Absorbed moisture is found to increase the toughness of both neat resin and reinforced nylon samples, but once dried again no significant difference in impact strength is found. A third test using a horizontal milling machine and a specially shaped tool is run to try and recreate the deformation that the rotating band sees when impacting the rifling of the gun. This test proved to be unsuccessful in generating brittle failure in glass-reinforced test samples.

Atmospheric boundary layer flows around wind turbines distributed in a large wind farm can be examined by the use of large eddy simulation (LES), which is based on the assumption that large eddies in the flow are anisotropic and depend on the mean flow and the configuration geometry, while smaller eddies are isotropic and homogeneous, and can be modeled via subgrid scale models. In this thesis, a pseudo-spectral LES code with inflow conditions imposed through a precursor concurrent simulation is utilized to model the flow around a single wind turbine or a large wind farm operating in thermally-stratified conditions. The effect of the wind turbines on humidity is monitored through an additional scalar convection equation. It is found that on average, the effect of an individual wind turbine on the humidity is less than 1%, while the effect of the wind farm on humidity can reach 1-2% in the cumulative wakes.

Forensic entomological field and laboratory studies were conducted to obtain data currently missing or conflicting in the literature. The first goal of this project was to identify and qualitatively assess the major taxa of forensic importance in southwest Virginia. Carcasses of the domestic pig, Sus scrofa L., were placed in field conditions and allowed to decompose until they reached the advanced stage of decay. Over 50 taxa were collected and identified, with Phormia regina, Phaenicia coeruleiviridis, Phaenicia sericata, Calliphora spp., Sarcophaga utilis, Musca domestica, Hydrotaea leucostoma, Stearibia nigriceps, Prochyliza xanthostoma, and Meroplius minutus among the most commonly observed fly species, and Creophilis maxillosus, Platydracus maculosus, Aleochara lata, Oiceoptoma noveboracense, Necrodes surinamensis, and Necrophila americana among the most commonly observed beetle species. The second objective of this study was to analyze successional patterns of taxa collected and identified in the carrion-insect succession studies. Occurrence matrices were constructed for the successional patterns of insect taxa during 21 sampling intervals in the spring and eight intervals in the summer studies. Permutation analyses of the occurrence matrices showed that the successional patterns of insect taxa were similar between spring 2001 and 2002 (P = 0.001) and between summer 2001 and 2002 (P = 0.007). Results indicated that the successional patterns appear to be typical for the seasonal periods. The third objective of this study was to analyze the effects of antemortem ingestion of ethanol by pigs on insect successional patterns and development rates. Pigs were dosed with a mixture of 95% ethanol and saline. Blood samples were collected immediately prior to euthanasia. The carcasses then were placed at an open field site and allowed to decompose. Insect samples were collected from carcasses for ten days post-mortem and the collected data were used to develop occurrence matrices. Permutation analysis to test the null hypothesis of no similarity between successional patterns of taxa from treated and untreated pigs showed that the successional patterns were similar. Loin meat from the carcasses was used as a rearing medium for field development studies of the black blow fly, Phormia regina. Development rates of 3rd instar P. regina maggots feeding on meat from treated pigs were significantly different from development rates of maggots feeding on meat from untreated pigs. No significant differences were detected in 1st and 2nd instars. Finally, the effect of relative humidity (RH) on egg hatch time and percent hatch rate of Phormia regina and Phaenicia coeruleiviridis was tested using saturated salt solutions. The global ANOVA of mean hatch times and percent hatch was found to be significant for P. regina at 20°C and 30°C and P. coerulieviridis at 20°C among RH levels at á = 0.05. T-test (LSD comparisons) results detected significant differences between some but not all RH levels within all three data series tested. Percent hatch observed varied widely, depending on the RH level. Of the levels tested, the lowest RH where hatch rate was observed was 53% (20°C) for P. coeruleiviridis, where only 1% of the eggs hatched. At 90+% RH, almost all of the eggs hatched for both species. / Ph. D.

No description available.

Factors governing the efficiency of convective moistening in the tropical upper troposphere between 15

People for long term exposed to an air-conditioned but highly humid environment are vulnerable to hyper-sensitivity or asthma triggered by fungi or dust mites. This thesis aims to develop a high-linearity and low-hysteresis capacitive relative humidity (RH) microsensor to more precisely accommodate the humidity of living spaces. To reduce the hysteresis and enhance the linearity, this research uses not only one polyimide (PI) thin film as a humidity sensing layer but also utilizes another PI thin film as a protecting layer of the top electrodes. To improve further the RH sensitivity and responding speed, interlacing out-of-plane electrodes are designed in the RH microsensor. The main processing steps of the RH sensor developed in this study involve at least five photolithographic and four thin film deposition processes. The influences of sensing area, number of electrode pairs and testing temperature on the sensitivity and sensing linearity of humidity microsensors were investigated. Based on the measurement results, the sensitivity apparently increase as well as the sensing area (2 mm ¡Ñ 2 mm: 0.12 pF/%RH, 3 mm ¡Ñ 3 mm: 0.48 pF/%RH, 5 mm ¡Ñ 5 mm: 1.09 pF/%RH), and decrease with the number of electrode pairs (40 pairs: 0.51 pF/%RH, 20 pairs: 0.4 pF/%RH) and increase with the testing temperature. The thesis has demonstrated that the capacitance of the RH sensor vary from the relative humidity with a very linear relationship (linearity: 98.8%~99.99%) over the range of 30~70%RH. Finally, to increase effectively the surface area and to reduce further the hysteresis, three-dimensional (3D) moisture entrances and exits were designed and a very low hysteresis value (0.5%RH) can be achieved.

Orientador: Fabiano Fruett / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-17T21:03:29Z (GMT). No. of bitstreams: 1 CostaJunior_JuvenilSeverinoda_M.pdf: 3663986 bytes, checksum: 04fada688bb589e761d7e3d0f1bc7715 (MD5) Previous issue date: 2011 / Resumo: Sensores de umidade relativa do ar estão sendo cada vez mais utilizados em sistemas de controle e aquisição de dados. Estes sensores são facilmente encontrados em estufas, automóveis, refrigeradores, equipamentos médicos, eletrodomésticos, instrumentos de precisão e outros. Mais recentemente, com o crescimento do mercado agrícola no Brasil, a demanda por sensores de umidade vem crescendo substancialmente. Este trabalho e dedicado ao estudo de um sistema sensor de umidade por detecção de ponto de orvalho utilizando uma ponte de impedância. A ponte de impedância foi microfabricada diretamente sobre um substrato de alumina que compõe uma pastilha Peltier. Um termistor também micro fabricado no mesmo substrato fornece o sinal necessário para a detecção do ponto de orvalho. A face fria da pastilha Peltier e resfriada ate alcançar a temperatura do ponto de orvalho do ar ao seu redor. Este resfriamento resulta na saturação do vapor de d'água presente no ar, fazendo com que gotículas de água condensem sobre o substrato de alumina. A condensação de água sobre os eletrodos da ponte de impedância causa um desbalanceamento que gera um sinal de controle para a pastilha Peltier. As temperaturas no limiar de condensação e ambiente são utilizadas no calculo da umidade relativa. Este sensor de umidade foi projetado para que alguns requisitos com relação a resistência contra contaminantes e baixa histerese fossem alcançados / Abstract: Sensors for relative humidity are being increasingly used in control systems and data acquisition. These sensors are easily found in greenhouses, cars, weather equipment, medical equipment, appliances, etc.. More recently, with the growth of the agricultural market in Brazil, the demand for humidity sensors has been growing substantially. This work is dedicated to the study of a humidity sensor for dew point detection using an impedance bridge. The impedance bridge was microfabricated directly on an alumina substrate that comprises a Peltier device. A thermistor also microfabricated on the same substrate control the temperature of the Peltier device to the threshold where the dew point produces the saturation of water vapor in the air. The cold face of the Peltier device is cooled until it reaches the dew point temperature. This cooling results in saturation of water vapor in the air, around the side of the Peltier device causing water droplets to condense on the alumina substrate. Water condensation on the electrodes of the impedance bridge causes an imbalance that generates a control signal to the Peltier device. The temperatures measured at the threshold of condensation along with ambient temperature are used to calculate the relative humidity. This sensor was designed to fulfill some requirements related to resistence to contaminants and low hysteresis / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica

The aim of this work was to solve problems with excessive humidity in buildings using data analysis. The theoretical part of the work deals with impacts of excessive humidity on the health of building occupants and also the condition of the building structure. Data mining methods including classification, prediction, and clustering are described together with model evaluation and selection. The practical part focuses on hardware platform description and measurement scenarios. Key parameters affecting indoor relative humidity are indoor and outdoor temperature and outdoor relative humidity. The long-term measurement of the mentioned parameters was performed using the set of sensors and BeeeOn system. Measured data was used to design a system for event detection related to a humidity change. The approach to air change regulation in the room was based on natural ventilation.