Coal mining in Pennsylvania has long been an important factor in the economic development of the commonwealth. However, the mines abandoned before today's strict environmental regulations have degraded over half of Pennsylvania's counties. Subsidence incidents, known as chimney caves, are in the form of sinkholes and develop above abandoned room-and-pillar mines. Chimney caving is the most dominant type of subsidence in southwestern Pennsylvania, yet there are no accurate means available to predict their occurrences. Therefore, an investigation has been conducted in order to develop a set of engineering criteria, or an equation, to predict such occurrences. Through conducting sand model experiments and through the collection of a chimney subsidence incident database, such an equation was derived, and verified using actual field data. / Master of Science

WIND-CHIMNEY Integrating the principles of a wind-catcher and a solar chimney to provide natural ventilation Fereshteh Tavakolinia Abstract This paper suggests using a wind-catcher integrated with a solar-chimney in a single story building so that the resident might benefit from natural ventilation, a passive cooling system, and heating strategies; it would also help to decrease energy use, CO2 emissions, and pollution. This system is able to remove undesirable interior heat pollution from a building and provide thermal comfort for the occupant.The present study introduces the use of a solar-chimney with an underground air channel combined with a wind-catcher, all as part of one device. Both the wind-catcher and solar chimney concepts used for improving a room’s natural ventilation are individually and analytically studied. This paper shows that the solar-chimney can be completely used to control and improve the underground cooling system during the day without any electricity. With a proper design, the solar-chimney can provide a thermally comfortable indoor environment for many hours during hot summers. The end product of this thesis research is a natural ventilation system and techniques that improve air quality and thermal comfort levels in a single story building. The proposed wind-chimney could eventually be designed for use in commercial, retail, and multi-story buildings.

The purpose of this investigation is to find out suitability of the solar chimney natural ventilation system in a Zero Energy Lab located at the University of North Texas campus, to figure out performance of the solar chimney. Reduction in the heating and ventilation and air conditioning energy consumption of the house has been also analyzed. The parameters which are considered for investigation are volumetric flow rate of outlet of chimney, the absorber wall temperature and glass wall temperatures. ANSYS FLUENT 14.0 has been employed for the 3-D modeling of the solar chimney. The dimensions of the solar chimney are 14’2” X 7’4” X 6’11”. The flow inside solar chimney is found to be laminar and the simulation results show that maximum outlet volumetric flow rate of about 0.12m3/s or 432 cfm is possible from chimney. The experimental velocity of chimney was found to be 0.21 m/s. Density Boussinesq approximation is considered for the modeling. Velocity and temperature sensors have been installed at inlet and outlet of the chimney in order to validate the modeling results. It is found that based on simulated volumetric flow rate that cooling load of 9.29 kwh can be saved and fan power of 7.85 Watts can be saved.

The purpose of this thesis is to describe the preliminary results from the investigation of shallow (<20m) hydrothermal vents with a total venting area of about 0.5 km2 off the eastern tip of Kueishantao Island. The chemical compositions of hot fluids, sediments and rocks as well as a continuous record of fluid temperature of a fumarole were measured in order to understand the venting process of hydrothermal fluids. The continuous temperature records show that the attainment of the maximum temperature of the hot fluids is related to the tidal cycle. The temperature variation seems to be associated with changes in the boiling point of seawater, which is affected by changes in water pressure. Such a correlation has not been reported in the literature. The hydrothermal fluids reach their highest temperature about 3.5 hours after each high tide, which is indicative of a shallow infiltration of seawater since the time it takes the boiling seawater to exit is so short. The hottest temperature recorded in our study area is 116¢J, while the lowest pH is 1.75, both a record in the world amid shallow hydrothermal systems. And, 1.75 is the lowest pH been reported on hydrothermal systems in the literature. At one point, the temperature recorder was covered with sand as a result of an encroaching typhoon. This suggests that the topography of the study area is susceptible to external forces. Based on salinity, the source of the hot fluids is taken to be ambient seawater, with no meteoric water from the islet involved. Concentrations of major ions in the hydrothermal fluids are almost the same as those in the ambient seawater. Mg is slightly enriched, however, which is unlike other hydrothermal fluids where, as reported elsewhere, Mg is generally lower because it replaces Ca in the bedrock. Low concentrations of Si in the studied fluids make for another distinct feature. Compared with other hydrothermal fluids in the world, the concentrations of Si in our study area are much lower, possibly on account of there being insufficient time for the rock to dissolve in the infiltrated seawater. Black and white smokers have widely been reported in the literature, but here are found heretofore unheard of yellow smokers as high as 6 meters. Other than one vent which emits liquid sulfur and forms a sulfur chimney, some vent sulfur from sulfur mounds. Still others are low- temperature vents which do not emit sulfur whatsoever. The most active venting activities are off the eastern tip of the islet. There are no other large reliefs associated with the hydrothermal activity, except for the chimney and a depression down to 35m deep. the chimney and a depression down to 35m deep. The composition of gravel on the seafloor is andesite, which is the same as the rock on the islet. The major composition of the sediments collected from the seafloor is sulfur, which is different from the sediments of the hydrothermal systems in the Okinawa Trough. The sulfur particles observed in this study originate from the fumaroles. Besides, sulfur balls the size of softballs and with distinct growth rings are found near some vents. The formation mechanism of these rings at this time, however, remains unclear. The bubbles from the vents are mostly made up of CO2, which is different from the composition of the shallow hot springs on the beach of Green islet. The 3He/4He of the emitted gas is high, this indicates that the gas may have originated from the mantle.

No description available.

Solar chimney is an important passive design strategy to maximize solar gain to enhance buoyancy effect for achieving adequate air flow rate and a desired level of thermal comfort inside a building. Therefore, solar chimney has the potential advantages over mechanical ventilation systems in terms of energy requirement, economic and environmental benefits. The main aim of this project is to study the technical feasibility of a solar chimney incorporating latent heat storage (LHS) system for domestic heating and cooling applications. The research work carried out and reported in this thesis includes: the development of a detailed theoretical model to calculate the phase change material (PCM) mass for solar chimney under specific climatic condition, the development of a CFD model to optimise the channel depth and the inlet and outlet sizes for the solar chimney geometry, experimental and numerical investigations of the thermal performance of the proposed system using a prototype set-up, a parametric study on the proposed system to identify significant parameters that affect the system performance was carried out by using the verified numerical model. The numerical and experimental study showed that the numerical model has the ability to calculate the PCM mass for the proposed system for the given weather conditions. The optimum PCM should be selected on the basis of its melting temperature, rather than its other properties such as latent heat. The experimental work on the thermal performance of the proposed system has been carried out. The results indicated that the LHS based solar chimney is technically viable. The outlet air temperature and the air flow rate varied within a small range during phase change transition period which are important for a solar air heating system. A numerical model was developed to reproduce the experimental conditions in terms of closed mode and open mode. The model results were in a close agreement with the experimental results particularly the simulated results for the discharging process. With the verified model, a comprehensive parametric analysis intended to optimise the thermal performance of proposed the system was performed. The results analysed are quantified in terms of charging/discharging time of the PCM, temperature difference between outlet air and inlet air of the solar chimney, and mass flow rate of the chimney, which are the most important quantities of the proposed system.

From the various studies, it can be concluded that the excessive summer heating and the humidity are one of the major problems of the hot, humid climatic region. The literature review for this study shows that natural ventilation alone cannot meet year long optimum indoor comfort in buildings. This research, through a design exercise, intends to verify whether a naturally ventilated house, in hot humid region of Austin, TX, can enhance its passive cooling potential through double‐walled wind catcher and solar chimney. In this research, a passive solar residence has been designed. Two designs have been explored on the chosen site: a basecase design without the wind catcher and solar chimney and another design with wind catcher and solar chimney. In the designcase, the placement of the wind catcher and the solar chimney has been designed so that a thermal siphon of airflow inside the building can be created. The design might show that there will be a natural airflow during the time of the year when natural wind does not flow. Moreover, the double walled wind catcher will resist the cool winter wind due to its shape and orientation. In the design, the placement of the wind catcher and the solar chimney has been done so that a thermal siphon inside the building can be created. Therefore, inside the home, there will be a natural airflow during the time of the year when natural wind does not flow. The double walled wind catcher has been designed and placed according to the orientation of the building in order to achieve the optimum wind flow throughout the year. The solar chimney has been placed in a certain part of the building where it can get maximum solar exposure. By comparing two cases, it can be clearly said that there will some kind of changed indoor comfort level. Since the potential of the design has been judged through perception, a computational fluid dynamics simulation analysis for a year is to be done.

The purpose of this study is to evaluate systematic fairy chimney development within Cappadocian ignimbrites. The first step in the sudy is to identify fairy chimney producing ignimbrites. Accordingly the fairy chimneys are formed within Kavak ignimbrite, at Kavak-Zelve transition, and within Zelve and Cemilk&ouml / y ignimbrites. Field measurements are taken from the fairy chimneys to quantify the shape and the size. Slope of the selected areas are identified to investigate the most suitable topography. Analysis have shown that fairy chimneys have basal diameters ranging from 9.7 to 13.7 m, with heights in the range from 8.41 to 21.73 m. The slopes of fairy chimneys are 60 to 70 degrees with a slight asymmetry towards the upslope. The chimneys are sligthy rounded due to the erosion in the slope direction. Distances between the fairy chimneys change from a minimum of 5.45 m for Zelve and 42.72 m for Kavak chimneys. Fairy chimneys are developed in two stages. The first stage is the generation of topography suitable for the formation of fairy chimneys. Three main factors in this stage are degree of welding, thickness of ignimbrite and topographic slope. In the second stage, several local features contribute for the final shaping of the chimneys.

Forest rings are large features common in Ontario’s boreal forests that comprise circular topographic depressions in carbonate mineral soil that are filled with peat. This thesis documents differences in peat and soil chemistry along transects across the “Bean” and “Thorn North” rings, which are centered on accumulations of CH4 and H2S, respectively. Within the mineral soil, ring edges are characterized by strong negative anomalies in pH, ORP and carbonate, as well as positive anomalies of Al, Fe and Mn in the results of aqua regia and hydroxylamine-hydrochloride digestions. Within the peat, positive carbonate and pH anomalies are recorded. This antithetic relationship suggests vertical migration of carbonate species from clay to peat. An inverse relationship exists between ORP, versus redox inferred from aqua regia. Strong ORP lows occur where oxidized products show highest concentrations. This is interpreted to reflect the proliferation of autotrophic organisms occupying the strong redox gradient at the ring edge.

Forest rings are large features common in Ontario’s boreal forests that comprise circular topographic depressions in carbonate mineral soil that are filled with peat. This thesis documents differences in peat and soil chemistry along transects across the “Bean” and “Thorn North” rings, which are centered on accumulations of CH4 and H2S, respectively. Within the mineral soil, ring edges are characterized by strong negative anomalies in pH, ORP and carbonate, as well as positive anomalies of Al, Fe and Mn in the results of aqua regia and hydroxylamine-hydrochloride digestions. Within the peat, positive carbonate and pH anomalies are recorded. This antithetic relationship suggests vertical migration of carbonate species from clay to peat. An inverse relationship exists between ORP, versus redox inferred from aqua regia. Strong ORP lows occur where oxidized products show highest concentrations. This is interpreted to reflect the proliferation of autotrophic organisms occupying the strong redox gradient at the ring edge.