Interactive Optimization Programs for Initial Propeller Design

This thesis presents two methods for initial design propeller optimization using constrained non- linear programming. The process uses the Nelder-Mead simplex algorithm. The Wageningen B-series optimal propeller selection is presented along with the combined annular momentum theory and blade element theory optimization. Both techniques require preliminary hull and engine design characteristics, but do not necessitate extensive background knowledge of pro- pellers and their calculations. A comparison of the two methods shows the combined annular momentum theory and blade element theory optimization produces the more e cient propeller. The optimization programs were designed with a graphic user interface implemented in the programming language Python

Curation Techniques of Small-sized Natural History Specimens: A Collection of Microfossils.

Small-sized fossil specimens are challenging regarding safety, storage and traceability of information. A recent collection of several hundred minute early mammalian teeth and jaws (most about 1mm) made impossible the standard practices of specimen numbering. A reliable association of the specimen and the collection number is the minimum required, however, a number of other data easily recoverable from the specimen/curating material is desirable. Geological provenance, locality, systematic and anatomical ID, collector, year, etc. is often included if possible. Use of the specimen is expected to be on the order of hundreds of years, manipulated by investigators, transported, and stored in collection museums together with millions of other specimens; mountings and labels must be resilient, reversible and stable. In our lab, we have developed new techniques to curate microfossils; the larger specimens (2-5 mm) are mounted with dental wax in the lid of inverted clear display boxes and the information duplicated in the lid carrying the specimen and the rest of the box cover. Hand written, printed labels and QR codes can be attached. Most specimens are much smaller, being preserved in ¼ dram vials (9x30mm), mounted on a cork via a shaped pin head/dental wax, and the vial acting as a cover. Printed labels include collection number and the systematic and geological precedence but not QR codes. Color-coding can be used to efficiently differentiate multiple localities in the compact collection. Wax allows easy demounting if needed and transparent boxes and vials facilitate handling and study without opening the containers.https://ir.library.louisville.edu/uars/1066/thumbnail.jp

Dimensional Analysis and Weak Turbulence

In the study of weakly turbulent wave systems possessing incomplete self-similarity it is possible to use dimensional arguments to derive the scaling exponents of the Kolmogorov-Zakharov spectra, provided the order of the resonant wave interactions responsible for nonlinear energy transfer is known. Furthermore one can easily derive conditions for the breakdown of the weak turbulence approximation. It is found that for incompletely self-similar systems dominated by three wave interactions, the weak turbulence approximation usually cannot break down at small scales. It follows that such systems cannot exhibit small scale intermittency. For systems dominated by four wave interactions, the incomplete self-similarity property implies that the scaling of the interaction coefficient depends only on the physical dimension of the system. These results are used to build a complete picture of the scaling properties of the surface wave problem where both gravity and surface tension play a role. We argue that, for large values of the energy flux, there should be two weakly turbulent scaling regions matched together via a region of strongly nonlinear turbulence.Comment: revtex4, 10 pages, 1 figur

Joint statistics of amplitudes and phases in Wave Turbulence

Random Phase Approximation (RPA) provides a very convenient tool to study the ensembles of weakly interacting waves, commonly called Wave Turbulence. In its traditional formulation, RPA assumes that phases of interacting waves are random quantities but it usually ignores randomness of their amplitudes. Recently, RPA was generalised in a way that takes into account the amplitude randomness and it was applied to study of the higher momenta and probability densities of wave amplitudes. However, to have a meaningful description of wave turbulence the RPA properties assumed for the initial fields must be proven to survive over the nonlinear evolution time, and such a proof is the main goal of the present paper. We derive an evolution equation for the full probability density function which contains the complete information about the joint statistics of all wave amplitudes and phases. We show that, for any initial statistics of the amplitudes, the phase factors remain statistically independent uniformly distributed variables. If in addition the initial amplitudes are also independent variables (but with arbitrary distributions) they will remain independent when considered in small sets which are much less than the total number of modes. However, if the size of a set is of order of the total number of modes then the joint probability density for this set is not factorisable into the product of one-mode probabilities. In the other words, the modes in such a set are involved in a ``collective'' (correlated) motion. We also study new type of correlators describing the phase statistics.Comment: 27 pages, uses feynmf packag

Parent preference in the attachment exploration balance in infancy: An experimental psychoanalytic approach

Fifteen 15-month old infants with mother as primary caretaker were observed in Ainsworth's Strange Situation modified to provide a simultaneous choice of mother or father during post-separation reunion episodes. Both exploratory and attachment behaviors were more significantly affected by separation from mother than from father, suggesting the greater importance of the mother as a secure base for exploration and as an attachment figure. The intrapsychic version of the parent most crucial to exploration and attachment at this age is that of mother, in whose absence the infant is not yet able to evoke the memory of the mother to sustain either exploratory behavior or the attachment bond adequately.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43951/1/10578_2004_Article_BF00706643.pd

Total and caspase-cleaved cytokeratin 18 in chronic cholecystitis: A prospective study

<p>Abstract</p> <p>Background</p> <p>Cell death mode has been studied in cancer, autoimmune, and neurodegenerative diseases. In this study, apoptosis and necrosis are investigated for the first time in patients with chronic calculous cholecystitis.</p> <p>Methods and materials</p> <p>Thirty five (35) patients (27 women and 8 men, aged 55.65 ± 13.48 years) with symptomatic chronic calculous cholecystitis underwent laparoscopic cholecystectomy. The early specific apoptotic tendency (caspase-cleaved cytokeratin 18) was studied in these patients with M30 Apoptosense ELISA and the total cytokerarin 18 (both derived from apoptosis and necrosis) with M65 ELISA. The ratio M30/M65 (caspase-cleaved to total cytokeratin 18) was also computed. According to the histopathological examination, the patients were divided in two groups: group A included patients with chronic inactive cholecystitis (n = 10), and group B those with chronic active cholecystitis (n = 25).</p> <p>Results</p> <p>The concentrations of caspase-cleaved cytokerarin 18 (CK18), and especially those of total CK18, were higher in bile samples than in serum samples. In group B, there were significant differences between serum and bile samples regarding both caspase-cleaved CK18 and total CK18. Cells staining positive for caspase-cleaved CK18 were present in the epithelial cells of the mucosa of the gallbladder.</p> <p>Conclusion</p> <p>CK18 is expressed in the gallbladder epithelial cells. The concentrations of both caspase-cleaved CK18 and total CK18 were higher in bile samples than in serum samples. The levels of total CK18, as well as caspase-cleaved CK18, do not seem to differ between active and inactive chronic cholecystitis.</p