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

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

P34 98. Leiomiomatosis con diseminación intravascular: Desde el útero a cavidades cardíacas y pulmón

ObjetivosLa leiomiomatosis uterina es un tumor mesenquimal poco frecuente, benigno, caracterizado por la proliferación de músculo liso en la luz vascular. Suele presentarse en mujeres de edad media, y presenta una enorme tendencia a la extensión intravascular y cardíaca. El tratamiento principalmente es quirúrgico para reducción de la masa tumoral, asociándose un bloqueo hormonal.MétodoPresentamos el caso de una mujer de 39 años, asintomática, con una plaquetopenia en estudio. Al realizarse una ecografía abdominal, se detecta una tumoración uterina de gran tamaño. La tomografía computarizada toracoabdominal objetivó extensión intravascular, a través de vena cava, extensión cardíaca hasta aurícula y ventrículo derecho, válvula tricúspide y arteria pulmonar hasta lechos parenquimatosos pulmonares.El tratamiento incluyó la realización de una histerectomía y doble anexectomía, asociándose una resección tumoral con acceso abdominal por laparotomía media desde cava inferior, y cirugía cardíaca con parada cardiocirculatoria, hipotermia profunda y perfusión anterógrada vía axilar, para resección tumoral intracardíaca.ResultadosLa evolución postoperatoria fue favorable. El estudio anatomopatológico diagnosticó una leiomiomatosis uterina con diseminación intravascular y cardíaca.ConclusionesLa leiomiomatosis uterina es una tumoración benigna con enorme tendencia a la extensión intravascular y cardíaca. Su tratamiento incluye resección tumoral y bloqueo hormonal de por vida, en mujeres jóvenes, generalmente. El tratamiento quirúrgico para resección tumoral exige control eco-cardiográfico para comprobar la completa resección del mismo

Language anxiety in Chinese dialects and Putonghua among college students in mainland China: the effects of sociobiographical and linguistic variables

This paper examined language anxiety (LA) in Chinese dialects and Putonghua among college students in mainland China and explored the links between their LA in the first language and a range of sociobiographical variables (i.e. gender and geographical background) as well as linguistic variables (i.e. mother tongue, age of onset of acquisition, context of learning, self-perceived oral proficiency, and frequency of use). Participants were 778 Beijing university students who speak Chinese dialects and Putonghua. Statistical analyses revealed that participants reported significantly higher levels of LA in dialects than in Putonghua across a variety of situations. Geographical background and gender had scattered effects on LA in Putonghua and in dialects. Early bilinguals whose mother tongue were both a dialect and Putonghua reported the least LA in both. Later age of onset and acquisition of Putonghua in an instructed context were linked to increased LA in Putonghua. The negative relationships between self-perceived oral proficiency, frequency of use and LA were stronger in Putonghua than in dialects. The higher levels of LA in dialects combined with their language practices in dialects suggest a relatively lower confidence in the use of dialects among in this group of highly educated young Chinese adults