1,669 research outputs found
Shuttle orbiter boundary layer transition at flight and wind tunnel conditions
Hypersonic boundary layer transition data obtained on the windward centerline of the Shuttle orbiter during entry for the first five flights are presented and analyzed. Because the orbiter surface is composed of a large number of thermal protection tiles, the transition data include the effects of distributed roughness arising from tile misalignment and gaps. These data are used as a benchmark for assessing and improving the accuracy of boundary layer transition predictions based on correlations of wind tunnel data taken on both aerodynamically rough and smooth orbiter surfaces. By comparing these two data bases, the relative importance of tunnel free stream noise and surface roughness on orbiter boundary layer transition correlation parameters can be assessed. This assessment indicates that accurate predications of transition times can be made for the orbiter at hypersonic flight conditions by using roughness dominated wind tunnel data. Specifically, times of transition onset and completion is accurately predicted using a correlation based on critical and effective values of a roughness Reynolds number previously derived from wind tunnel data
Resolving candidate genes of mouse skeletal muscle QTL via RNA-Seq and expression network analyses
Peer reviewedPublisher PD
Test Equipment Serial Communication Interface Rs-232 Db-9 Type Connectors on Testing Techniques Insitu
At this writing will be made prober interface RS-232 in situ testing (testing onlocation) when the system interfaces operate without causing disturbances operatingsystem itself. For that tool is designed so that the information will be observed in thetest can be easily accessed via the display in the form of light and the values of thesignal information in the form of voltage level. To avoid the imposition of thiscommunication interface, the tool is equipped with the buffer. It is expected that thistool can provide rapid information, communication failures in the process of datathrough computer communication port
Spectral and dynamic characteristics of buried-heterostructure single quantum well (Al,Ga)As lasers
We demonstrate that, as predicted, (Al,Ga)As single quantum well (SQW) lasers have substantially narrower spectral linewidths than bulk double-heterostructure lasers. We have observed a further major reduction (>3Ă) in the linewidth of these SQW lasers when the facet reflectivities are enhanced. This observation is explained theoretically on the basis of the very low losses in coated SQW lasers and the value of the spontaneous emission factor at low threshold currents. We also report on the modulation frequency response parameter of these SQW lasers
Soil Nutrients and Vegetation Characteristics of a Dorset/Thule Site in the Canadian Arctic
We conducted a systematic study of soils and vegetation present at Arnaqquaksaat on Igloolik Island, Nunavut, a site occupied by Dorset and Thule people prior to 1823 and probably for over a thousand years. We compared this site to an area affected by ongoing mammal and bird activity and an area of relatively unfertilized polar semidesert. At these locations, we estimated percent cover of vegetation, identified vascular plant species, measured soil depth, and collected soil samples. The soil samples were analyzed for total nitrogen, sodium bicarbonate-extractable phosphorus, available potassium, available magnesium, and pH.Percent plant cover, abundance of plant species indicative of enrichment, and soil depth were greatest within the area of anthropogenic influence and decreased downslope to the sea. Total nitrogen level in the upslope area of anthropogenic influence (2.61% ±0.88) was similar to that in areas of bird and mammal activity (2.54% ±0.78); it was higher than the levels in the downslope area of human fertilization (0.65% ±0.82) and the unaltered polar semidesert area (0.28% ±0.38). Phosphorus levels in the influenced areas were 5 to 6 times those in the uninfluenced polar semidesert. The magnesium level was highest in the area of bird and mammal activity (766.8 mg/L ±53.35), whereas potassium levels were similar throughout the study area. The lowest pH was found in the upslope area of past human occupation, and pH differences among sites paralleled those observed for nitrogen.On a effectuĂ© une Ă©tude systĂ©matique des sols et de la vĂ©gĂ©tation prĂ©sents Ă Arnaqquaksaat dans l'Ăźle Igloolik au Nunavut, un site occupĂ© par les peuples de Dorset et de ThulĂ© avant 1823 et probablement durant plus de mille ans. On a comparĂ© ce site Ă une zone affectĂ©e par l'activitĂ© continue de mammifĂšres et d'oiseaux et Ă une zone de semi-dĂ©sert polaire relativement non fertilisĂ©. Ă ces endroits, on a Ă©valuĂ© le pourcentage de couvert vĂ©gĂ©tal, identifiĂ© les espĂšces de plantes vasculaires, mesurĂ© la profondeur du sol et prĂ©levĂ© des Ă©chantillons de sol. On a analysĂ© ces derniers pour en Ă©valuer la teneur en azote total, phosphore extractible par le bicarbonate de soude, potassium disponible, magnĂ©sium disponible et le pH. On a trouvĂ© que le pourcentage de couvert vĂ©gĂ©tal, l'abondance d'espĂšces vĂ©gĂ©tales rĂ©vĂ©latrice d'un enrichissement et la profondeur du sol Ă©taient les plus importants Ă l'intĂ©rieur de la zone qui avait subi une influence anthropique et qu'ils dĂ©croissaient en descendant vers la mer. Le niveau d'azote total dans la zone supĂ©rieure de la pente, qui avait subi une influence anthropique (2,61 p. cent ± 0,88), Ă©tait semblable Ă celui des zones oĂč s'exerçait l'activitĂ© des oiseaux et des mammifĂšres (2,54 p. cent ± 0,78); il Ă©tait supĂ©rieur aux niveaux trouvĂ©s dans la partie infĂ©rieure qui avait connu une fertilisation humaine (0,65 p. cent ± 0,82) et dans la zone polaire semi-dĂ©sertique non altĂ©rĂ©e (0,28 ± 0,38). Les niveaux de phosphore dans les zones ayant subi une influence Ă©taient de 5 Ă 6 fois ceux des zones semi-dĂ©sertiques polaires n'ayant pas subi d'influence. Le niveau de magnĂ©sium Ă©tait le plus haut dans la zone oĂč s'exerçait l'activitĂ© des oiseaux et des mammifĂšres (766,8 mg/L ± 53,35), alors que les niveaux de potassium Ă©taient semblables dans toute la zone d'Ă©tude. Le pH le plus bas se trouvait dans la zone supĂ©rieure de l'endroit ayant jadis Ă©tĂ© occupĂ© par l'ĂȘtre humain, et les diffĂ©rences dans le pH parmi les sites s'alignaient sur celles observĂ©es pour l'azote
Space Shuttle orbiter entry heating and TPS response: STS-1 predictions and flight data
Aerothermodynamic development flight test data from the first orbital flight test of the Space Transportation System (STS) transmitted after entry blackout is given. Engineering predictions of boundary layer transition and numerical simulations of the orbiter flow field were confirmed. The data tended to substantiate preflight predictions of surface catalysis phenomena. The thermal response of the thermal protection system was as expected. The only exception is that internal free convection was found to be significant in limiting the peak temperature of the structure in areas which do not have internal insulation
Pengaruh Suhu Dan Komposisi Minyak Jagung Pada Pembuatan Lilin Klowong Terhadap Pewarnaan Batik
Batik is one of the most highly developed Indonesian art forms that had been designated by UNESCO as a Masterpiece of oral and intangible Heritage of Humanity. It uses techniques of wax resist dyeing applied to the whole cloth and can be made by using canting or printing.Once the design applied on the cloth, then it is ready to be waxed and the staining of the batik cloth depends on the quality of the wax. Therefore, batik wax is considered as the main material to make batik, especially for handmade batik in which the pattern and carve applied directly by the artisans. Vegetable oil is to improvement viscosity level in liquidity of batik waxes and to knowing the effect of the dyed batik.This research aims to knowing the composition of the required yellow paraffin waxes batik and to knowing the effect of the composition of the yellow paraffin dyed batik. This study uses qualitative and quantitative methods with material measurement techniques, and test a questionnaire to evaluate the response of the respondents to the sharpness of the color produced. In the process of making batik wax, the composition of the materials used are Lilin tawon, damar mata kucing, gondorukem, yellow parafin, and  vegetable oils. In this research, yellow paraffin as an independent variable with variations in different compositions (10 g, 15 g, 20 g and 25 g). To test the composition of the wax batik then made 4 different samples, each sample has a different composition yellow paraffin. To view a sample of the batik conducted several tests, including testing the sharpness of color, smearing of colors, as well as washing with soap, while the qualitative testing done by kuisioer to test visually, from the test results of samples both quantitative and qualitative data show that the results of batik using sample C gives better results than other samples
Ares-I-X Stability and Control Flight Test: Analysis and Plans
The flight test of the Ares I-X vehicle provides a unique opportunity to reduce risk of the design of the Ares I vehicle and test out design, math modeling, and analysis methods. One of the key features of the Ares I design is the significant static aerodynamic instability coupled with the relatively flexible vehicle - potentially resulting in a challenging controls problem to provide adequate flight path performance while also providing adequate structural mode damping and preventing adverse control coupling to the flexible structural modes. Another challenge is to obtain enough data from the single flight to be able to conduct analysis showing the effectiveness of the controls solutions and have data to inform design decisions for Ares I. This paper will outline the modeling approaches and control system design to conduct this flight test, and also the system identification techniques developed to extract key information such as control system performance (gain/phase margins, for example), structural dynamics responses, and aerodynamic model estimations
Control of weld composition when arc welding high strength aluminium alloys using multiple filler wires
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