784 research outputs found
Wind-tunnel/flight correlation study of aerodynamic characteristics of a large flexible supersonic cruise airplane (XB-70-1). 3: A comparison between characteristics predicted from wind-tunnel measurements and those measured in flight
A program was undertaken by NASA to evaluate the accuracy of a method for predicting the aerodynamic characteristics of large supersonic cruise airplanes. This program compared predicted and flight-measured lift, drag, angle of attack, and control surface deflection for the XB-70-1 airplane for 14 flight conditions with a Mach number range from 0.76 to 2.56. The predictions were derived from the wind-tunnel test data of a 0.03-scale model of the XB-70-1 airplane fabricated to represent the aeroelastically deformed shape at a 2.5 Mach number cruise condition. Corrections for shape variations at the other Mach numbers were included in the prediction. For most cases, differences between predicted and measured values were within the accuracy of the comparison. However, there were significant differences at transonic Mach numbers. At a Mach number of 1.06 differences were as large as 27 percent in the drag coefficients and 20 deg in the elevator deflections. A brief analysis indicated that a significant part of the difference between drag coefficients was due to the incorrect prediction of the control surface deflection required to trim the airplane
The ultracool dwarf DENIS-P J104814.7-395606. Chromospheres and coronae at the low-mass end of the main-sequence
We have obtained an XMM-Newton observation and a broad-band spectrum from the
ultraviolet to the near infrared with X-Shooter for one of the nearest M9
dwarfs, DENIS-P J1048-3956 (4pc). We integrate these data by a compilation of
activity parameters for ultracool dwarfs from the literature with the aim to
advance our understanding of these objects by comparing them to early-M type
dwarf stars and the Sun.
Our deep XMM-Newton observation has led to the first X-ray detection of
DENIS-P J1048-3956 (log Lx = 25.1) as well as the first measurement of its V
band brightness (V = 17.35mag). Flux-flux relations between X-ray and
chromospheric activity indicators are here for the first time extended into the
regime of the ultracool dwarfs. The approximate agreement of DENIS-P J1048-3956
and other ultracool dwarfs with flux-flux relations for early-M dwarfs suggests
that the same heating mechanisms work in the atmospheres of ultracool dwarfs,
albeit weaker as judged from their lower fluxes. The observed Balmer decrements
of DENIS-P J1048-3956 are compatible with optically thick plasma in LTE at low,
nearly photospheric temperature or optically thin LTE plasma at 20000K.
Describing the decrements with CaseB recombination requires different emitting
regions for Halpha and the higher Balmer lines. The high observed Halpha/Hbeta
flux ratio is also poorly fitted by the optically thin models. We derive a
similarly high value for the Halpha/Hbeta ratio of vB10 and LHS2065 and
conclude that this may be a characteristic of ultracool dwarfs. We add DENIS-P
J1048-3956 to the list of ultracool dwarfs detected in both the radio and the
X-ray band. The Benz-Guedel relation between radio and X-ray luminosity of
late-type stars is well-known to be violated by ultracool dwarfs. We speculate
on the presence of two types of ultracool dwarfs with distinct radio and X-ray
behavior.Comment: accepted for publication in Astronomy & Astrophysic
Effect of number of probes and their orientation on the calculation of several compressor face distortion descriptors
A study was performed to determine the effects of the number and position of total pressure probes on the calculation of five compressor face distortion descriptors. This study used three sets of 320 steady state total pressure measurements that were obtained with a special rotating rake apparatus in wind tunnel tests of a mixed-compression inlet. The inlet was a one third scale model of the inlet on a YF-12 airplane, and it was tested in the wind tunnel at representative flight conditions at Mach numbers above 2.0. The study shows that large errors resulted in the calculation of the distortion descriptors even with a number of probes that were considered adequate in the past. There were errors as large as 30 and -50 percent in several distortion descriptors for a configuration consisting of eight rakes with five equal-area-weighted probes on each rake
The usefulness of Olanzapine plasma concentrations in monitoring treatment efficacy and metabolic disturbances in first-episode psychosis
Introduction: The role of Olanzapine therapeutic drug monitoring is controversial. The present study explores the associations of Olanzapine plasma concentrations with clinical response and metabolic side effects in first episode psychosis (FEP) after 2 months of treatment. Methods: Forty-seven patients were included. Improvement in clinical symptomatology was assessed using the PANSS. Metabolic assessment included weight, blood pressure, waist circumference, blood glucose, total cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides. Results: The Olanzapine plasma concentrations after 2 months of treatment were positively correlated with weight gain (r = 0.49, p = 0.003), and a concentration > 23.28 ng/mL was identified as a positive predictor of weight gain (≥ 7%). The Olanzapine concentration to dose (C/D) ratio was positively correlated with the percentage of improvement in the total PANSS (r = 0.46, p = 0.004), and a C/D ratio > 2.12 was identified as a positive predictor of a good response (percentage of improvement > 30%) after 2 months of treatment. We also identified several factors that could alter Olanzapine pharmacokinetics: gender (p = 0.03), diagnosis (p = 0.05), smoking habit (p = 0.05), and co-medications such as valproic acid (p = 0.05) and anxiolytics (p = 0.01). Discussion: In conclusion, our results suggest that therapeutic drug monitoring of Olanzapine could be helpful to evaluate therapeutic efficacy and metabolic dysfunction in FEP patients treated with Olanzapine
Long-term acute infections during a bovine viral diarrhea virus (BVDV) outbreak in dairy farm from Galicia (NW Spain)
An observational study describes an outbreak of bovine viral diarrhea virus (BVDV) in a dairy herd in Spain. The herd was subjected to a voluntary control program. In a sampling carried out in June 2020, bulk tank milk antibody levels increased compared to the previous sampling. Additionally, serum samples from 4 young heifers also tested positive for antibodies. Since the results were consistent with a recent infection, we proceeded to detect possible persistently infected (PI) animals using antigen ELISA (on serum/ear-notch samples), following the program guidelines. From this moment on, 42 animals tested positive for BVDV antigen, of which 17 were under typical acute infection (AI), 13 were deemed as PI, and eight died early on the farm before having information to determine their status. The remaining 4 showed intriguing test results consistent with a long-term AI since they tested BVDV positive in at least two antigen tests more than 3 weeks apart. Thus, one animal was positive until 80 days of age in serum, and others even for longer periods in ear-notch samples, until they finally tested negative for BVDV. Based on these results, longer follow-up may be necessary in BVDV positive animals to accurately confirm persistent infectionS
Applications of infrared thermography in sports. A review
La termografía infrarroja (TI) registra el calor irradiado de un cuerpo, que es emitido en un rango del espectro electromagnético que la visión humana no es capaz de identificar. La respuesta térmica depende de una serie de ajustes fisiológicos específicos como la homeostasis corporal y salud del deportista, lo cual permite establecer interesantes aplicaciones en el deporte. El objetivo de este trabajo ha sido revisar la literatura en torno a las aplicaciones de la TI en el ámbito del deporte, y proponer las características óptimas del registro en relación al evaluado, las condiciones ambientales y la cámara utilizada. Concluimos que la principal contribución de la TI en el ámbito del deporte es ayudar a identificar
signos de lesión antes de que la lesión se produzca, permitiéndonos actuar de manera preventiva durante el proceso de entrenamientoInfrared thermography (IRT) records the radiant heat of a body, which is emitted in the range of the electromagnetic spectrum that human vision is not able to identify. The thermal response depends on a number of specific physiological adjustments as body homeostasis and athlete’s health, which allow us to establishing interesting applications in sport. The aim of this study was to review the literature on IRT applications in sports, and to propose the optimal characteristics of the register in terms of the subject, the environmental conditions and the camera used. We conclude that the main contribution of IRT in the field of sport is to help identify signs of injury before it occurs, allowing us to act proactively along the training proces
Supplements of carbohydrates long during exercise: Effects on the electrolytes and glucose
Objetivo: Identificar si la forma de presentación de los suplementos de
carbohidratos (SC) influye en la respuesta de la concentración plasmática de
electrólitos y glucosa durante un ejercicio de larga duración. Doce hombres realizaron cuatro pruebas de 90 min en cicloergometro (55-60%VO2máx),
seguidas por 6 km a máxima velocidad, consumiendo SC en diferentes
presentaciones (líquido, gel o sólido) y un día únicamente consumían agua. Se
analizaron las concentraciones de sodio, potasio y glucosa en sangre antes del
ejercicio, cada 30 minutos de prueba, y tras los 6 km. No hubo diferencia
significativa en la respuesta de los electrolitos durante todo estudio. Hubo
diferencias significativas (p<0,05) en la glucosa cuando se consumieron SC
independientemente de su presentación frente al consumo exclusivo de agua.
Se concluye que la forma de presentación de los SC no influye en la
concentración de glucosa en sangre durante el ejercicio de larga duraciónObjective: To identify if the format of carbohydrate supplements (CS) influence
the response of the plasmatic concentration of electrolytes and glucose during
long duration exercise. Twelve men performed four tests of 90 min on a cycle
ergometer (55-60% VO2max), followed by 6 km at maximum speed, consuming
CS in different forms (liquid, gel or solid) and one day just consuming water. It
was analyzed the concentrations of sodium, potassium and blood glucose
before exercise, every 30 minutes of test, and after 6 km. There was no
significant difference in the response of electrolytes during the study. However,
the glucose showed significant differences (p <0.05) when it was consumed CS
regardless of their form, whenever just water was consumed. In this way is
possible to conclude, that the format of the SC does not affect the blood
glucose concentration during long duration exercis
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