26,820 research outputs found
Large eddy simulations and direct numerical simulations of high speed turbulent reacting flows
This research is involved with the implementations of advanced computational schemes based on large eddy simulations (LES) and direct numerical simulations (DNS) to study the phenomenon of mixing and its coupling with chemical reactions in compressible turbulent flows. In the efforts related to LES, a research program was initiated to extend the present capabilities of this method for the treatment of chemically reacting flows, whereas in the DNS efforts, focus was on detailed investigations of the effects of compressibility, heat release, and nonequilibrium kinetics modeling in high speed reacting flows. The efforts to date were primarily focussed on simulations of simple flows, namely, homogeneous compressible flows and temporally developing hign speed mixing layers. A summary of the accomplishments is provided
Analysis of short pulse laser altimetry data obtained over horizontal path
Recent pulsed measurements of atmospheric delay obtained by ranging to the more realistic targets including a simulated ocean target and an extended plate target are discussed. These measurements are used to estimate the expected timing accuracy of a correlation receiver system. The experimental work was conducted using a pulsed two color laser altimeter
Impact of Teat Order on Feed Consumption in Swine from Birth to Nursery
A relationship between teat order and feed consumption has been assumed in pigs, but no study has looked at this exact relationship. Pigs were observed shortly after birth to be in either a cranial, middle, or caudal teat positon. Growth performance data and active and total plasma ghrelin concentrations were analyzed at birth, weaning, and at the end of the nursery stage of production to see if a relationship with teat order was present. Overall, no effect of teat order was found on average daily gain, average daily feed intake, gain-to-feed ratio, or body weight among pigs from each section of the udder. Differences did occur during certain stages of nursery, which can be of economic importance to producers. No difference was seen in active or total ghrelin levels or the active-to-total ghrelin ratio in relation to teat order, although there were differences in active and total ghrelin concentrations among the sampling days. Further research should be carried out to investigate what factors would contribute to this data contradicting previous inferences about the relationship of teat order and feed consumption in pigs
An Exploratory Study of Investigating the Creative Potential of Taiwanese Children
The question of whether creativity should be viewed as domain-general or domain-specific, and unidimensional or multidimensional, have led to a vibrant discussion among students of creativity. Following a reviewing of the relevant literature, it was decided that the present study would focus its investigation of the creative potential of Taiwanese students on verbal and visual creative abilities. Three major findings were found: first, that the relationship between verbal and visual creativity was moderate and significant, while the relationship between ideational behavior, on the one hand, and verbal creativity and visual creativity, on the other, was weak and non-significant. Second, as illustrated by our perceptual map, it appears that verbal and visual creativity are different constructs, which might tend to support the domain-specific theory of creativity. Finally, gender did not function as a moderator between verbal and visual creativity
Charmed Baryon Weak Decays with SU(3) Flavor Symmetry
We study the semileptonic and non-leptonic charmed baryon decays with
flavor symmetry, where the charmed baryons can be , , , or . With denoted as the baryon
octet (decuplet), we find that the
decays are forbidden, while the ,
, and decays are the only existing Cabibbo-allowed modes
for , , and , respectively. We predict the rarely studied
decays, such as and . For the observation, the doubly and triply charmed baryon decays of
, ,
, and are the favored Cabibbo-allowed decays,
which are accessible to the BESIII and LHCb experiments.Comment: 29 pages, no figure, a typo in the table correcte
Transmission Scanning Acoustic Microscopy for Tilted Plate Specimens
In transmission scanning acoustic microscopy (SAM) [1,2,3] the plate-specimen under examination is usually aligned with its surface normal parallel to the lens axis in order to optimize the spatial resolution. However, we have found that in many instances a higher acoustic transmission and additional image contents can be facilitated by tilting the specimen such that its surface normal is at a small angle with respect to the lens axis (Fig. 1). For a small tilt angle, the image degradation due to reduced spatial resolution is insignificant with relatively small numerical aperture lenses
Further Progress on Nondestructive Diagnosis of Hybrid Microelectronic Components Using Transmission Acoustic Microscopy
Recent progress on diagnosis and characterization of defects in hybrid microelectronic components us1ng a transmission scanning acoustic microscope (SAM) operating at 150 MHz is summarized. A simple method has been established to locate (in three dimensions) and classify the defects. The study also shows that two optically identical thick-film resistors having a ratio of 5 x 103 in resistance value exhibit a 43 db contrast in acoustic amplitude
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