Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of General Science, 1924. / Includes bibliographical references (leaf 11). / by W.C. Groce, P.L. Miller. / B.S.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of General Science, 1926. / by Choong Myung Ko. / B.S.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of General Science, 1931. / Includes bibliographical references (leaf 47). / Preface: The purpose of this thesis was to investigate the insulation properties of aluminium foil. The use of aluminium foil as a heat insulator though used in the British Isles and on the continent particularly in Germany where it was first developed commercially, is comparatively unknown in this country. This is due to two principal reasons. First, a psychological one, namely the natural inertia of the users of heat insulating materials to adopt any new material which differs radically both in action and appearance to the common insulating materials on the market. The second reason, a practical one is that there is little knowledge of its insulation value in this country. Practically all of the data on aluminium foil as insulation has heretofore come almost entirely from German sources. This is undoubtedly an additional reason why insulation users shy at the use of aluminium foil. To meet this condition this thesis was undertaken at the suggestion of the Alfol Insulation Company, Inc., which holds the American rights to the original German patents. / by Robert M. Kelly. / B.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of General Science, 1928. / Includes bibliographical references (leaves 43-44). / by Grandison Gardner. / M.S.

Thesis: B.S., Massachusetts Institute of Technology, Department of General Science, 1945 / B.S. / B.S. Massachusetts Institute of Technology, Department of General Science

Thesis (B.S.)-- Massachusetts Institute of Technology, Dept. of General Science, 1924 [first author], and Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of General Engineering, 1924 [second author]. / Includes bibliographical references (leaf 29). / by Horacio Serrano Palma and Arthur M. Kallet. / B.S.

In support of the National Oceanic and Atmospheric Administration (NOAA) National Weather Service&rsquo / s (NWS) flash flood warning and heavy precipitation forecast efforts, the NOAA National Environmental Satellite Data and Information Service (NESDIS) Center for Satellite Applications and Research (STAR) has been providing satellite based precipitation estimates operationally since 1978. Two of the satellite based rainfall algorithms are the Hydro-Estimator (HE) and the Self-Calibrating Multivariate Precipitation Retrieval (SCaMPR). Satellite based rainfall algorithms need to be adjusted for the orographic events and atmospheric variables for the continued improvement of the estimates. However, unlike the HE algorithm, the SCaMPR does not currently make any adjustments for the effects of complex topography on rainfall estimate. Bias structure of the SCaMPR algorithm suggests that the rainfall algorithm underestimates precipitation in case of upward atmospheric movements and high temperature levels. Also SCaMPR algorithm overestimates rainfall in case of downward atmospheric movements and low temperature levels. A regionally dependent empirical elevation-based bias correction technique and also a temperature based bias correction technique may help to improve the quality of satellite-derived precipitation products. In this study, an orographic correction method and a temperature correction method that will enhance precipitation distribution, improve accuracy and remove topography and temperature dependent bias is developed for the Self-Calibrating Multivariate Precipitation Retrieval (SCaMPR) rainfall algorithm to be used in operational forecasting for meteorological and hydrological applications.

The present thesis aims at shedding some light for future applications of &amp / #956 / AVs by investigating the hovering mode of flight by flapping motion. In this study, a detailed numerical investigation is performed to investigate the effect of some geometrical parameters, such as the airfoil profile shapes, thickness and camber distributions and as well as the flapping motion kinematics on the aerodynamic force coefficients and vortex formation mechanisms at low Reynolds number. The numerical analysis tool is a DNS code using the moving grid option. Laminar Navier-Stokes computations are done for flapping motion using the prescribed kinematics in the Reynolds number range of 101-103. The flow field for flapping hover flight is investigated for elliptic profiles having thicknesses of 12%, 9% and 1% of their chord lengths and compared with those of NACA 0009, NACA 0012 and SD 7003 airfoil profiles all having chord lengths of 0.01m for numerical computations. Computed aerodynamic force coefficients are compared for these profiles having different centers of rotation and angles of attack. NACA profiles have slightly higher lift coefficients than the ellipses of the same t/c ratio. And one of the most important conclusions is that the use of elliptic and NACA profiles with 9% and 12% thicknesses do not differ much as far as the aerodynamic force coefficients is concerned for this Re number regime. Also, two different sinusoidal flapping motions are analyzed. Force coefficients and vorticity contours obtained from the experiments in the literature and present study are compared. The validation of the present computational results with the experimental results available in the literature encourages us to conclude that present numerical method can be a reliable alternative to experimental techniques.

An algorithm has been developed for snow recognition (SR) over mountainous areas of Europe from satellite imagery. The algorithm uses Meteosat Second Generations (MSG) instrument Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) data that are acquired in every 15 minutes through whole day. Although SEVIRI has low spatial resolution, its high temporal resolution provides a better discrimination capacity between ice clouds and snow. Discrimination of snow and clouds is the most challenging part of snow recognition algorithm development. The proposed algorithm relies on Satellite Application Facility to support Nowcasting and Very Short Range Forecastings (SAFNWC) cloud products. A final thematic map has been produced which is consisting of 3 different classes: snow, cloud and land. Validation of the SEVIRI SR product was held in three stages.The obtained high performance of the SR product is presented with the analysis results.

This study has been carried out to develop and manufacture piezoelectric ceramic materials which are utilized for ultrasonic motor (USM) applications. For this purpose, the effect of compositional modifications on the dielectric and piezoelectric properties of lead zirconate titanate (PZT) based ceramics was investigated. PZT based powders were produced using the mixed oxide method. The base composition was selected as Pb(Zr0.54Ti0.46)O3. The samples in the proximity of morphotrophic phase boundary were doped with strontium, lanthanum, lead manganese niobate (PMnN) and lead manganese antimonate (PMS) in order to improve the structural characteristics and electromechanical properties which are very important for USM applications. The dielectric constant, planar coupling coefficient, mechanical quality factor, piezoelectric strain constant and tangent loss values were evaluated in accordance with standard IRE (Institute of Radio Engineers) test procedures. The results on dielectric and piezoelectric properties showed that piezoelectric ceramics with high mechanical quality factor, high piezoelectric strain constant and low tangent loss could be produced by using the aforementioned dopants. As a result, a new piezoelectric ceramic named as 0.97[PSLZT]-0.024[PMnN]-0.006[PMS] was produced with KT= 1913, Qm= 1240, d33= 540 pC/N, tan delta= 0.89%, kp= 0.57 and Tc= 235 &deg / C. This composition is a good candidate for high power applications. The ceramic samples with the developed compositions were used to produce an ultrasonic-wave type motor and the performance of the USM was evaluated in terms of speed, torque and efficiency.