Experimental verification of computer spray-combustion models

Analytical model formulation, representing performance of spray-combustion device, is based on understanding of atomization, mixing, vaporization, and combustion which occurs in device. Report lists results of correlations of computed values with values obtained from experiments with rocket combustor. Technique offers excellent method for evaluating validity and ranges of applicability of combustion models

Two-stage combustion for reducing pollutant emissions from gas turbine combustors

Combustion and emission results are presented for a premix combustor fueled with admixtures of JP5 with neat H2 and of JP5 with simulated partial-oxidation product gas. The combustor was operated with inlet-air state conditions typical of cruise power for high performance aviation engines. Ultralow NOx, CO and HC emissions and extended lean burning limits were achieved simultaneously. Laboratory scale studies of the non-catalyzed rich-burning characteristics of several paraffin-series hydrocarbon fuels and of JP5 showed sooting limits at equivalence ratios of about 2.0 and that in order to achieve very rich sootless burning it is necessary to premix the reactants thoroughly and to use high levels of air preheat. The application of two-stage combustion for the reduction of fuel NOx was reviewed. An experimental combustor designed and constructed for two-stage combustion experiments is described

An experimental correlation of the nonreactive properties of injection schemes and combustion effects in a liquid-propellant rocket engine. Part II. Instrumentation, experimental apparatus, and experimental techniques

Apparatus, techniques, and instrumentation for experimental correlation of nonreactive injection schemes and combustion effects in liquid propellant rocket engin

Stress-Induced Cocaine Seeking Requires a Beta-2 Adrenergic Receptor-Regulated Pathway from the Ventral Bed Nucleus of the Stria Terminalis That Regulates CRF Actions in the Ventral Tegmental Area

The ventral bed nucleus of the stria terminalis (vBNST) has been implicated in stress-induced cocaine use. Here we demonstrate that, in the vBNST, corticotropin releasing factor (CRF) is expressed in neurons that innervate the ventral tegmental area (VTA), a site where the CRF receptor antagonist antalarmin prevents the reinstatement of cocaine seeking by a stressor, intermittent footshock, following intravenous self-administration in rats. The vBNST receives dense noradrenergic innervation and expresses β adrenergic receptors (ARs). Footshock-induced reinstatement was prevented by bilateral intra-vBNST injection of the β-2 AR antagonist, ICI-118,551, but not the β-1 AR antagonist, betaxolol. Moreover, bilateral intra-vBNST injection of the β-2 AR agonist, clenbuterol, but not the β-1 agonist, dobutamine, reinstated cocaine seeking, suggesting that activation of vBNST β-2 AR is both necessary for stress-induced reinstatement and sufficient to induce cocaine seeking. The contribution of a β-2 AR-regulated vBNST-to-VTA pathway that releases CRF was investigated using a disconnection approach. Injection of ICI-118,551 into the vBNST in one hemisphere and antalarmin into the VTA of the contralateral hemisphere prevented footshock-induced reinstatement, whereas ipsilateral manipulations failed to attenuate stress-induced cocaine seeking, suggesting that β-2 AR regulate vBNST efferents that release CRF into the VTA, activating CRF receptors, and promoting cocaine use. Last, reinstatement by clenbuterol delivered bilaterally into the vBNST was prevented by bilateral vBNST pretreatment with antalarmin, indicating that β-2 AR-mediated actions in the vBNST also require local CRF receptor activation. Understanding the processes through which stress induces cocaine seeking should guide the development of new treatments for addiction

Automatic speech recognition research at NASA-Ames Research Center

A trainable acoustic pattern recognizer manufactured by Scope Electronics is presented. The voice command system VCS encodes speech by sampling 16 bandpass filters with center frequencies in the range from 200 to 5000 Hz. Variations in speaking rate are compensated for by a compression algorithm that subdivides each utterance into eight subintervals in such a way that the amount of spectral change within each subinterval is the same. The recorded filter values within each subinterval are then reduced to a 15-bit representation, giving a 120-bit encoding for each utterance. The VCS incorporates a simple recognition algorithm that utilizes five training samples of each word in a vocabulary of up to 24 words. The recognition rate of approximately 85 percent correct for untrained speakers and 94 percent correct for trained speakers was not considered adequate for flight systems use. Therefore, the built-in recognition algorithm was disabled, and the VCS was modified to transmit 120-bit encodings to an external computer for recognition

Neotropical tineidae, II: biological notes and descriptions of two new moths phoretic on spiny pocket mice in Costa Rica (Lepidoptera: Tineoidea)

Journal ArticleTwo new species of tineid moths discovered riding on the backs of two species of spiny pocket mice (Heteromyidae) in Costa Rica are described. Amydria selvae, new species, was found on Heteromys desmarestianus Gray in the rainforest at Finca La Selva and Ptilopsaltis santarosae, new species, occurred on Liomys salvini (Thomas) in the dry forest at Santa Rosa National Park. Only female moths were observed and collected. Biological observations on both moths and their hosts in phoresy are summarized

Influence of bill shape on ectoparasite load in Western Scrub-Jays

Journal ArticlePopulations of the Western Scrub-Jay (Aphelocoma californica) have bills specialized for feeding in their respective habitats. Populations in oak habitat have hooked bills, whereas those in pinyon habitat have pointed bills with a reduced maxillary overhang. Work on other bird species shows that the bill overhang is essential for efficient preening to control ectoparasites. Given the importance of this overhang, we predicted that louse-infested jays with pointed bills would have higher louse loads than those with hooked bills. We compared the number of lice on 65 pointed-billed (4 infested) and 105 hooked-billed (17 infested) birds. Despite their lower incidence of louse infestation, pointed-billed birds had significantly more lice than hooked-billed birds, supporting our prediction

Experimental test of the importance of preen oil in Rock Doves (Columba livia)

Journal ArticleMost species of birds have a uropygial gland, also known as a preen gland, which produces oil that birds spread through their plumage when preening. The plumage of waterfowl deprived of uropygial oil becomes brittle and is subject to breakage

An experimental correlation of the nonreactive properties of injection schemes and combustion effects in a liquid-propellant rocket engine. Part VI - The relation between the starting transient and injection hydraulics

Gas pressurized, liquid bipropellant injection feed system starting flow transient criteria - effects on combustion stabilit