The purpose of this study is to investigate variation in water export and instream temperatures throughout the open water season in a beaded Arctic stream, consisting of small pools connected by shallow chutes. The goals are to better understand heat and mass movement through these systems, how this may impact chemical and biological processes, and the resulting shifts with changes in climate. This is accomplished by first examining the extent and variability of water storage and export through qualitative analysis of observational data. Further, heat fate and transport is examined through development of an instream temperature model. The model formulation, a simple approach to model calibration and validation, and information regarding residence and characteristic times of different pool layers are presented. Using temperatures measured at high spatial resolution within the pools and surrounding bed sediments as well as other supporting data (e.g., instream flow, specific conductivity, weather data, and bathymetry), various types of storage within the pools, banks, and marshy areas within the riparian zone, including subsurface flow paths that connect the pools, were found. Additionally, data illustrated that some pools will stay stratified during higher flow periods under certain weather conditions. Through modeling efforts, the dominant heat sources were found to vary between stratified layers. It was also found that potential increases in thaw depths surrounding these pools can shift stratification and mixing patterns. These shifts can further influence mass export dynamics and instream water quality. Given the amount and different types of storage within these systems and the influence of stratification patterns on the residence times in the pools, Imnavait Basin and similar beaded Arctic watersheds will likely experience delayed export of nutrients that are limiting in most Arctic systems.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21155号 / 農博第2281号 / 新制||農||1059(附属図書館) / 学位論文||H30||N5129(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 川島 茂人, 教授 星野 敏, 教授 藤原 正幸 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Heat stress is influenced by environmental conditions, workload and clothing. A critical environment is the upper limit of compensable heat stress for a given metabolic rate and clothing ensemble. The physiological strains associated with heat stress are core and skin temperatures, heart rate and physiological strain index (PSI). Because heat dissipation mechanisms may differ between men and women, there may be gender differences in the critical environment and the associated physiological variables. Gender differences were explored between acclimated men (n = 20) and women (n = 9) at the upper limit of compensable heat stress. Participants walked on a motorized treadmill at a target metabolic rate of 160W/m2 while wearing five different clothing ensembles (cotton work clothes, cotton coveralls, and three coveralls of particle barrier, liquid barrier, and vapor barrier properties). The starting air temperature (Tdb) was 34°C and humidity was held constant at 50%. Once thermal equilibrium was achieved, Tdb was increased 1°C every five minutes until loss of thermal equilibrium or termination criteria were met. Upon initial analysis, several gender differences were found. A significant difference (p = 0.035) was found for WBGTcrit, where values were 32.5°C for men and 33.1°C for women. Women had higher average heart rates (hr = 125 and 112 bpm), average skin temperatures (Tsk =36.4 and 36.2°C), and psi values (4.5 and 3.8) than men. No significant difference was found between genders for core temperature (tre) (p = 0.147). The target metabolic rate of 160W/m2 was not achieved and there were significant differences (p <0.0001) between men (172 W/m2) and women (152 W/m2). The effects of metabolic rate on WBGTcrit was examined and it was discovered that the difference in WGBTcrit could be explained by the difference in metabolic rate. The same logic was applied to the physiological responses and confirmed a difference between genders for Tre, HR, and PSI. The differences for Tsk disappeared. These findings indicate that women experienced a greater cardiovascular strain at the critical conditon and also greater heat strain than men at the same heat load.

Made available in DSpace on 2014-12-17T15:01:32Z (GMT). No. of bitstreams: 1 ThayseNPD_DISSERT.pdf: 3011136 bytes, checksum: 3c14c7c4fc8b4067013feadbd30be411 (MD5) Previous issue date: 2013-08-08 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The objective of this work was the development and improvement of the mathematical models based on mass and heat balances, representing the drying transient process fruit pulp in spouted bed dryer with intermittent feeding. Mass and energy balance for drying, represented by a system of differential equations, were developed in Fortran language and adapted to the condition of intermittent feeding and mass accumulation. Were used the DASSL routine (Differential Algebraic System Solver) for solving the differential equation system and used a heuristic optimization algorithm in parameter estimation, the Particle Swarm algorithm. From the experimental data food drying, the differential models were used to determine the quantity of water and the drying air temperature at the exit of a spouted bed and accumulated mass of powder in the dryer. The models were validated using the experimental data of drying whose operating conditions, air temperature, flow rate and time intermittency, varied within the limits studied. In reviewing the results predicted, it was found that these models represent the experimental data of the kinetics of production and accumulation of powder and humidity and air temperature at the outlet of the dryer / O objetivo principal deste trabalho foi o estudo e aperfei?oamento de modelos matem?ticos, baseados em balan?os de massa e de energia, que representem o processo de secagem transiente de polpas de frutas em secador de leito de jorro com alimenta??o intermitente. Os balan?os de massa e de energia para a secagem, representados por um sistema de equa??es diferenciais, foram desenvolvidos em linguagem Fortran e adaptados para a condi??o de alimenta??o intermitente e de ac?mulo de massa no interior do equipamento. Este programa realiza a integra??o deste sistema de equa??es diferenciais utilizando a rotina DASSL (Differential Algebraic System Solver) e o procedimento de estima??o do par?metro do modelo foi fundamentado na minimiza??o da fun??o objetivo da t?cnica de m?nimos quadrados utilizando um m?todo heur?stico de otimiza??o PSO (Particle Swarm Optimization). Utilizando dados experimentais gerados nas pesquisas de secagem de alimentos realizadas nos laborat?rio de Tecnologia de Alimentos e de Sistemas Particulados da UFRN, determinaram-se equa??es emp?ricas estat?sticas e aplicaram-se os modelos referentes aos balan?os para verifica??o da quantidade de ?gua e da temperatura do ar de secagem na sa?da do leito de jorro e da massa de material acumulada no secador. Os modelos foram validados a partir dos dados experimentais de secagens cujas condi??es operacionais, de temperatura do ar, vaz?o da pasta e tempo de intermit?ncia, variavam dentro dos limites estudados. Na an?lise dos resultados preditos, foi constatado que estes modelos representam bem os dados experimentais da cin?tica de produ??o e de ac?mulo de p? e da umidade e da temperatura do ar na sa?da do secado

The diploma thesis deals with preliminary design of condensing steam turbine with three unregulated steam outputs and its gland steam system particularly its description and design. The steam parameters in key outputs were determined in heat balance. The gland steam system parameters were calculated for different operating conditions. It also describes influence of pressure on performance of turbine in gland steam system. Finally, the inquiry sheet for gland steam system device was created based on calculated values.

This thesis focuses on the analysis of heat efficiency and effectiveness of the Vojtěchov biogas station unit. The material balances were developed in connection with biogas created in the cogeneration unit. The heat produced by the cogeneration unit is distributed to reactors and drying rooms. Pursuing the main goal of the thesis, the research of the complete heating balance for all months has been conducted. Additionally, a variety of options were assessed, to find the best solution of how to increase the effectivity of the heat. As for the final solution, two recommendations have been proposed in the thesis. The first recommendation lies in a better usage of low-level heat distributed to the secondary fermentor. The second suggestion deals with the amount of heat from cogeneration unit to the system. The result of the analysis is the final recommendation on how to increase the efficiency of the heat usage and potential impacts of the solution on the subsidy according to the KVET standards received in the given year.

This thesis deals with rotary drying and sintering kilns. The first part focused upon construction of the kilns, kiln processes and the options of technological arrangement of the kilns. The thesis second part presents two experiments. The first one is targeted to find the relation between residence time, kiln rotary speed and kiln slope in longitudinal direction. The examinations analysed individually the relation between kiln rotary speed and residence time and the relation between kiln slope and residence time. Finally, the regression equation describing the relation between holding time, kiln rotary speed and kiln rake was established. The results given by regression equation much closer to the real one then the results given by literature. The difference between real residence time and the regression one is about one minute. The second one is concerned with producing a set of equations with respect of mass and heat balance in case of drying process. The input material was wet crushed tetra packs. There were established technological conditions of the material, necessary burner energy input, heat losses and distribution of heat between material and flue gas. There were taken away almost 80 percent of heat energy by flue gases. The remaining 20 percent was divided between latent heat, material and heat losses through the shell of the rotary kiln.

The aim of this diploma thesis is a design and thermodynamical calculation of a steam condensing turbine with one controlled steam extraction and assigned technical specifications. Technical specifications are turbine inlet temperature 440,0 °C, pressure of inlet steam 38,0 bar(a), pressure in controlled steam extraction 13,0 bar(a), mass flow rate of steam in controlled steam exraction 0,0-40 t/h, temperature in deaerator 105,0 °C and temperature of cooling water in condenser 25,0 °C. Designed steam turbine works in a Rankine-Clausius cycle with a water-cooled condenser, system of low-pressure feed water heater, feed water tank with deaerator and steam boiler. Turbine was designed with regular turbine stages with reaction type of blading and with two regulation stages with impulse blading. An extraction turbine map of the steam turbine is shown in the last chapter of this work. Final parameters of steam turbine are power of 21,7 kW, internal efficiency of turbine 85,1 % and reheat factor 1,048.

This master's thesis is deals with type designing and implementing the steam turbine to the machine part of heat plant in reconstruction. The thesis consists of two parts. First part is theoretical explanation of the heating industry, steam turbines, thermal cycles and components of thermal power plants. Second part of the thesis describes the design and calculation of thermal diagrams based on turbine parameters, which were provided from Tenza, a.s. tender. There is a simplified calculation of technical-economic study in the conclusion of the thesis. The thesis output is recommendation of single final implementation solution for customer.

Diploma thesis deals with the design of a condensing steam turbine with one controlled steam extraction. Its working range is 0 to 10 t/h. The first part contains the design of the heat balance scheme. The turbine has two unregulated steam extractions for low-pressure feedwater heater and outlet steam is cooled by water condenser. The main part is the design of the turbine flow channel with one regulative stage using impulse blading and 26 regular stages using reaction blading. The turbine rotating speed is 8500 rpm, which is strength suitable even in critical points. The following chapters are describing the design of the compensation piston and bearings. The consumption characteristic of the steam turbine is shown in the last chapter. Drawing of the turbine section is attached to this thesis. Final turbine power is 9259,7 kW and thermodynamic efficiency 85,5 %.