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This work describes the design, implementation, and calibration of NOAA's coherent, pulsed, Doppler lidar. This lidar was used to acquire 252 high quality, independent measurements of atmospheric backscattering profiles from 4 to 30 km altitude over Boulder, Colorado, at a wavelength of 10.6 micrometers between May 1981 and May 1983, a period that includes the injection and removal of debris from the El Chichon eruptions. Statistical analyses of the data set by computer show that atmospheric backscattering is approximately lognormally distributed for all but the lowest altitudes, and a theoretical explanation is offered for this property. Seasonally-averaged profiles and altitudinally-stacked, filtered time sequences show the volcanic cloud appearing in the stratosphere and falling through the tropopause into the troposphere at rates far higher than can be explained by gravitational settling alone. The dynamic process of tropopause folding is proposed as the dominant mechanism for the observed exchange of volcanic debris from the stratosphere to the troposphere. This hypothesis is supported by case studies of mid-tropospheric backscatter-enhancing events. Mie calculations and comparisons with other measurements show that vertically-integrated backscatter is a good long-term measure of total atmospheric mass loading of volcanic debris. It is found that the time constant which characterizes debris removal is 208 days for the stratosphere and 60 days for the troposphere. No appreciable debris is removed before the volcanic cloud falls to 6 km altitude 420 days after the volcanic eruptions.

Call number: LD2668 .T4 1985 C47 / Master of Science

Call number: LD2668 .T4 1986 B724 / Master of Science / Physics

The dynamical mass determination of galaxies and systems of galaxies shows a large excess of mass above what one observes directly. This excess of mass indicates the presence of dark matter. The nature of this dark matter is still unknown and dark matter in the outer regions of large stellar structures such as clusters of galaxies might provide enough matter to close the universe. In this dissertation we investigate in detail the mass distribution of the Coma cluster. We show that optical data alone are unable to distinguish between a wide range of possible mass distribution for the Coma cluster. Low-mass models must have larger central density than high-mass models and require that the galaxies move on near-circular orbits, whereas high-mass models require the galaxy orbits to be predominantly radial. The optical data constrain the amount of dark matter very poorly. The X-ray data can also be used for a mass determination of the Coma cluster. These data may require the mass of the cluster to be more concentrated to the core than a light-traces-mass model if the central temperature of the gas is high. However, they do not put any constraint on the mass distribution beyond a Mpc or two. The above analysis, and most other approaches, assume the existence of dark matter. An alternative approach has been proposed by Milgrom (1983a,b,c): in his theory, the Newtonian law of motion breaks down in a weak field, and must be modified. The present analysis shows that this model is also consistent with optical and X-ray data on the Coma cluster, although a good fit required values for Milgrom's "universal" parameter aₒ to be 2h¹·⁵ (Hₒ = 50 h km/s/Mpc) higher than those inferred from the rotation curves of spiral galaxies. Finally, we investigate whether the model of an expanding cluster dominated by a massive binary galaxy, first suggested by Valtonen and Byrd (1979), is consistent with optical data on the surface density and velocity dispersion of the Coma cluster. We simulate the evolution of this model for a wide variety of initial conditions. We find that galaxy counts in the model can be made to agree with observation, but that the observed velocity dispersion profile cannot be reproduced. A number of other arguments suggest that the central galaxies in Coma cannot be as massive as required by the model. This model is not a viable representation of the Coma cluster.

This study presents a comprehensive overview of the significance and results of implementing a data analysis for the calibration of an iodine neutrino detector. Previous neutrino detectors have failed to confirm the standard solar model or settle the question of a massive neutrino. An iodine detector, which was proposed in 1988, is being constructed to hopefully resolve these issues. Before the iodine detector can give conclusive results, it must first be calibrated. Because there is no standard neutrino source, these calibrations must be done indirectly. The method for calibrating the 127-Iodine detector is by using a (p,n) reaction at 0' on an iodine target and a proton beam provided by the Indiana University Cyclotron FacHity (IUCF). When a neutrino is captured by 127-Iodine, the nucleus becomes an excited state of 127-Xenon at an energy of 125 keV. By measuring the Gwnow Teller strength fimction of the transition from the ground state in 127-Iodine to the 125 keV excited state in 127-Xenon, the iodine detector can be suitably calibrated. / Department of Physics and Astronomy

Approximately 30% of the UK s housing stock is comprised of older, solid wall buildings. Solid walls have no cavity and were built without insulation; therefore these buildings have high heat loss, can be uncomfortable for occupants throughout the winter and require an above-average amount of energy to heat. Solid wall buildings can be made more energy efficient by retrofitting internal wall insulation (IWI). However, there is little empirical evidence on how much energy can be saved by insulating solid wall buildings and there are concerns that internal wall insulation could lead to overheating in the summer. This thesis reports measured results obtained from a unique facility comprised of a matched pair of unoccupied, solid wall, semi-detached houses. In the winter of 2015 one house of the pair was fitted with internal wall insulation then both houses had their thermal performance measured to see how differently they behaved. Measuring the thermal performance was the process of measuring the wall U-values, the whole house heat transfer coefficient and the whole house airtightness of the original and insulated houses. Both houses were then monitored in the winter of 2015, monitoring was the process of measuring the houses energy demand while using synthetic occupancy to create normal occupancy conditions. In the summer of 2015 indoor temperatures were monitored in the houses to assess overheating. The monitoring was done firstly to see how differently an insulated and an uninsulated house perform under normal operating conditions: with the blinds open through the day and the windows closed. Secondly, a mitigation strategy was applied to reduce high indoor operative temperatures in the houses, which involved closing the blinds in the day to reduce solar gains and opening the windows at night to purge warm air from the houses. The original solid walls were measured to have U-values of 1.72 W/m2K, while with internal wall insulation the walls had U-values of 0.21 W/m2K, a reduction of 88%. The house without IWI had a heat transfer coefficient of 238 W/K; this was reduced by 39% to 144 W/K by installing IWI. The monitored data from winter was extrapolated into yearly energy demand; the internally insulated house used 52% less gas than before retrofit. The measured U-values, whole house heat loss and energy demand were all compared to those produced from RdSAP models. The house was found to be more energy efficient than expected in its original state and to continue to use less energy than modelled once insulated. This has important implications for potential carbon savings and calculating pay-back times for retrofit measures. In summer, operative temperatures in the living room and main bedroom were observed to be higher, by 2.2 oC and 1.5 oC respectively, in the internally insulated house in comparison to the uninsulated house. Both of these rooms overheated according to CIBSE TM52 criteria; however the tests were conducted during an exceptionally warm period of weather. With the simple mitigation strategy applied the indoor operative temperature in the internally insulated house was reduced to a similar level as observed in the uninsulated house. This demonstrates that any increased overheating risk due to the installation of internal wall insulation can be mitigated through the use of simple, low cost mitigation measures. This research contributes field-measured evidence gathered under realistic controlled conditions to show that internal wall insulation can significantly reduce the energy demand of a solid wall house; this in turn can reduce greenhouse gas emissions and could help alleviate fuel poverty. Further to this it has been demonstrated that in this archetype and location IWI would cause overheating only in unusually hot weather and that indoor temperatures can be reduced to those found in an uninsulated house through the use of a simple and low cost mitigation strategy. It is concluded that IWI can provide a comfortable indoor environment, and that overheating should not be considered a barrier to the uptake of IWI in the UK.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1985 S54 / Master of Science