The Hubble Space Telescope archive contains a large collection of images of eta Carinae, and this paper analyses those most suitable for measuring its expanding Homunculus Nebula. Multiple intensity tracings through the Homunculus reveal the fractional increase in the overall size of the nebula; this avoids registration uncertainty, mitigates brightness fluctuations, and is independent of previous methods. Combining a 13 yr baseline ofWide Field Planetary Camera 2 images in the F631N filter, with a 4 yr baseline of Advanced Camera for Surveys/ High Resolution Channel images in the F550M filter, yields an ejection date (assuming linear motion) of 1847.1 (+/- 0.8 yr). This result improves the precision, but is in excellent agreement with the previous study by Morse et al., that used a shorter time baseline and a different analysis method. This more precise date is inconsistent with ejection during a periastron passage of the eccentric binary. Ejection occurred well into the main plateau of the Great Eruption, and not during the brief peaks in 1843 and 1838. The age uncertainty is dominated by a real spread in ages of various knots, and by some irregular brightness fluctuations. Several knots appear to have been ejected decades before or after the mean date, implying a complicated history of mass-loss episodes outside the main bright phase of the eruption. The extended history of mass ejection may have been largely erased by the passage of a shock through clumpy ejecta, as most material was swept into a thin shell with nearly uniform apparent age.

In this thesis we study the interaction of supernova ejecta in the environment of young massive clusters. It has been already shown that winds of massive stars can be thermalized by mutual interactions inside the cluster and drive the strong star cluster wind. The SNe are, as discrete and extremely energetic events, in all ways diferent from the continuous stellar winds. This triggers the question under which parameter and if at all can the SNe ejecta interaction from a smooth star cluster wind. Therefore we at first parametrize the SNe explossions and based on the 3D simulations in FLASH we show for the first time that the convergence of the SNe ejecta interaction to a smooth star cluster wind is controlled by a single parameter ΠSN . The paramater ΠSN estimates the mean number of interacting SN ejecta based on a comparison of supernova rate and crossing time of SN ejecta in a cluster. For high enough values ΠSN > 1 the cluster is able to build up smooth a star cluster wind. This allows us to use a 1D semi-analytic code WINDCALC to calculate the cooling of the hot gas due to dust and estimate under which conditions the SNe-inserted matter is captured. This may explain the origin of so-called anomalous globular clusters. 1

In this study we conduct wind resource assessment to evaluate the annual energy production of a wind turbine. To estimate energy production of a wind turbine over a period of time, the power characteristics of the wind turbine are integrated with the probabilities of the wind speed expected at a chosen site. The first data set was obtained from a wind farm in Denmark. We propose several probability density functions to model the distribution of the wind speed. We use techniques from nonlinear regression analysis to model the power curve of a wind turbine. The best fit distribution model is assessed by performing numeric goodness–of–fit measures and graphical analyses. Johnson’s bounded (SB) distribution provides the best fit model with the smallest Kolmogorov–Smirnov (K-S) test statistic . 15. The four parameter logistic nonlinear regression (4PL) model is determined to provide the best fit to the power curve data, according to the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). The estimated annual energy yield is compared to the actual production of the wind turbine. Our models underestimate the actual energy production by a 1 difference. In Chapter Six we conduct data processing, analyses and comparison of wind speed distributions using a data set obtained from a measuring wind mast mounted in Humansdorp, Eastern Cape. The expected annual energy production is estimated by using the certified power curve as provided by the manufacturer of the wind turbine under study. The commonly used Weibull distribution is determined to provide the best fit distribution model to our selected models. The annual energy yield is estimated at 7.33 GWh, with a capacity factor of 41.8 percent.

No description available.

This thesis investigates atmospheric gusts and their effect on aircraft.

We calculate the circularly polarized Stokes V(λ) profile for emission lines, formed in hot-star winds threaded with a weak split monopole magnetic field. Invoking the weak-field approximation, we find that the V(λ) profile has a characteristic shape with the ubiquitous sign reversal across line center, but also with a sign reveral in each wing. For the optically thin lines treated here, we also conclude that the V(λ) profile integrates to zero on each side of the line separately. The overall scale of V(λ)/I(λ) is set by the ratio of the field strength to the flow speed, B/v, characteristic of the line-forming region, and is of the order of 0.1% for a wind magnetic field B ≅ 100 G at depths where the windspeed is v ≅ 100 km s-1.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1975. / Bibliography: leaves 94-96. / by Barbara A. Emery. / M.S.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Meteorology. / Microfiche copy available in Archives and Science. / Bibliography: leaves 182-191. / by Richard Robert Babcock, Jr.. / Ph.D.

No description available.

by Lee Kwok Lun. / Title also in Chinese characters. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 145-147). / ACKNOWLEDGEMENTS --- p.iii / ABSTRACT --- p.iv / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- WINTER MONSOON IN EAST ASIA / Chapter 1.2 --- THE SURGES AND THE EFFECTS ON LOCAL WEATHER / Chapter 1.3 --- PREDICTION OF WINTER MONSOON SURGES / Chapter 1.4 --- COASTAL FEATURES AT OTHER PLACES / Chapter 1.5 --- OBJECTIVES AND METHODOLOGY / Chapter CHAPTER 2 --- THE NUMERICAL MODEL --- p.10 / Chapter 2.1 --- THE GOVERNING EQUATIONS / Chapter 2.1.1 --- INDEPENDENT VARIABLES / Chapter 2.1.2 --- DEPENDENT VARIABLES / Chapter 2.1.3 --- THE COMPLETE SET OF MODEL EQUATIONS / Chapter 2.2 --- MODEL DOMAIN AND GRID STRUCTURE / Chapter 2.3 --- SPATIAL FINITE DIFFERENCE SCHEMES / Chapter 2.3.1 --- ADVECTION TERMS / Chapter 2.3.2 --- DIFFUSION TERM / Chapter 2.3.3 --- PRESSURE GRADIENT FORCE TERM / Chapter 2.3.4 --- INTEGRATION OF HYDROSTATIC EQUATION / Chapter 2.4 --- TIME INTEGRATION SCHEME / Chapter 2.5 --- LATERAL BOUNDARY CONDITIONS / Chapter 2.6 --- PARAMETERIZATION OF PHYSICAL PROCESSES / Chapter 2.6.1 --- PLANETARY BOUNDARY LAYER PHYSICS / Chapter 2.6.2 --- EVALUATION OF DIABATIC HEATING / Chapter 2.7 --- INITIALIZATION / Chapter CHAPTER 3 --- SIMULATIONS OF ACTUAL EASTERLY COLD SURGE EVENTS --- p.32 / Chapter 3.1 --- CHOICE OF MODEL DOMAIN / Chapter 3.2 --- INITIAL AND LATERAL BOUNDARY DATA / Chapter 3.3 --- THE ACTUAL EVENTS / Chapter 3.3.1 --- CASE STUDY1A / Chapter 3.3.1.1 --- Synoptic Environment During the Event / Chapter 3.3.1.2 --- The Simulation of the Actual Event / Chapter 3.3.1.3 --- Diagnosis of the Simulation Results / Chapter 3.3.2 --- CASE STUDY2A / Chapter 3.3.3. --- CASE STUDY3A / Chapter 3.4 --- SUMMARY / Chapter CHAPTER 4 --- NUMERICAL EXPERIMENTS ON THE OROGRAPHIC EFFECTS ON THE EASTERLY COLD SURGE --- p.77 / Chapter 4.1 --- THE NUMERICAL EXPERIMENTS / Chapter 4.2 --- NO TERRAIN EXPERIMENTS / Chapter 4.3 --- EFFECTS OF TAIWAN ISLAND / Chapter 4.4 --- IDEAL COASTAL RANGE EXPERIMENTS / Chapter 4.5 --- SUMMARY / Chapter CHAPTER 5 --- THEORETICAL CONSIDERATION OF THE FORMATION OF THE COASTAL NARROW RIDGE --- p.96 / Chapter 5.1 --- INTRODUCTION / Chapter 5.2 --- THE KELVIN WAVE MODEL / Chapter 5.3 --- COMPARISON OF COASTAL PHENOMENA AT OTHER PLACES / Chapter 5.3.1 --- THE AUSTRALIA CASE / Chapter 5.3.2 --- THE NORTH AMERICA CASE / Chapter 5.4 --- THE SOUTHEAST CHINA COASTAL RIDGE / Chapter 5.5 --- OTHER MECHANISMS BESIDES OROGRAPHIC EFFECTS / Chapter CHAPTER 6 --- CONCLUSION --- p.109 / APPENDIX A DERIVATION OF GOVERNING EQUATIONS --- p.112 / APPENDIX B HORIZONTAL SMOOTHING AND HORIZONTAL DIFFUSION --- p.120 / APPENDIX C DIAGNOSTIC VARIABLES --- p.122 / APPENDIX D EXTERNAL AND INTERNAL KELVIN WAVES --- p.125 / APPENDIX E FORTRAN SOURCE CODE OF THE NUMERICAL MODEL --- p.129 / REFERENCES --- p.147