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PubMed1998

Lunar surface magnetic fields and their interaction with the solar wind: results from lunar prospector

The magnetometer and electron reflectometer experiment on the Lunar Prospector spacecraft has obtained maps of lunar crustal magnetic fields and observed the interaction between the solar wind and regions of strong crustal magnetic fields at high selenographic latitude (30 degreesS to 80 degreesS) and low ( approximately 100 kilometers) altitude. Electron reflection maps of the regions antipodal to the Imbrium and Serenitatis impact basins, extending to 80 degreesS latitude, show that crustal magnetic fields fill most of the antipodal zones of those basins. This finding provides further evidence for the hypothesis that basin-forming impacts result in magnetization of the lunar crust at their antipodes. The crustal magnetic fields of the Imbrium antipode region are strong enough to deflect the solar wind and form a miniature (100 to several hundred kilometers across) magnetosphere, magnetosheath, and bow shock system.

Journal Article↗

PubMed1999

Solar wind outflow and the chromospheric magnetic network

Observations of outflow velocities in coronal holes (regions of open coronal magnetic field) have recently been obtained with the Solar and Heliospheric Observatory (SOHO) spacecraft. Velocity maps of Ne7+ from its bright resonance line at 770 angstroms, formed at the base of the corona, show a relationship between outflow velocity and chromospheric magnetic network structure, suggesting that the solar wind is rooted at its base to this structure, emanating from localized regions along boundaries and boundary intersections of magnetic network cells. This apparent relation to the chromospheric magnetic network and the relatively large outflow velocity signatures will improve understanding of the complex structure and dynamics at the base of the corona and the source region of the solar wind.

Journal Article↗

PubMed2000

Solar wind record on the moon: deciphering presolar from planetary nitrogen.

Ion microprobe analyses show that solar wind nitrogen associated with solar wind hydrogen implanted in the first tens of nanometers of lunar regolith grains is depleted in 15N by at least 24% relative to terrestrial atmosphere, whereas a nonsolar component associated with deuterium-rich hydrogen, detected in silicon-bearing coatings at the surface of some ilmenite grains, is enriched in 15N. Systematic enrichment of 15N in terrestrial planets and bulk meteorites relative to the protosolar gas cannot be explained by isotopic fractionation in nebular or planetary environments but requires the contribution of 15N-rich compounds to the total nitrogen in planetary materials. Most of these compounds are possibly of an interstellar origin and never equilibrated with the 15N-depleted protosolar nebula.

Argon↗

PubMed2005

Cardiorespiratory adjustments of homing pigeons to steady wind tunnel flight.

We made detailed cardiorespiratory measurements from homing pigeons during quiet rest and steady wind tunnel flight. Our pigeons satisfied their 17.4-fold increase in oxygen consumption during flight with a 7.4-fold increase in cardiac output (Q) and a 2.4-fold increase in blood oxygen extraction. Q was increased primarily by increasing heart rate sixfold. Comparisons between our study and those from the only other detailed cardiorespiratory study on flying birds reveal a number of similarities and important differences. Although the avian allometric equations from this earlier study accurately predicted the flight Q of our pigeons, this was primarily due to due to compensating discrepancies in their heart rate and stroke volume predictions. Additionally, the measured heart mass (MH)-specific Q (Q/MH) of our pigeons during wind tunnel flight was about 22% lower than the estimated value. Compared to running mammals in previous studies, the 1.65-fold Q of our pigeons is consistent with their larger heart mass.

Animals↗

PubMed1996

Wingbeat frequency and the body drag anomaly: wind-tunnel observations on a thrush nightingale (Luscinia luscinia) and a teal (Anas crecca)

A teal (Anas crecca) and a thrush nightingale (Luscinia luscinia) were trained to fly in the Lund wind tunnel for periods of up to 3 and 16 h respectively. Both birds flew in steady flapping flight, with such regularity that their wingbeat frequencies could be determined by viewing them through a shutter stroboscope. When flying at a constant air speed, the teal's wingbeat frequency varied with the 0.364 power of the body mass and the thrush nightingale's varied with the 0.430 power. Both exponents differed from zero, but neither differed from the predicted value (0.5) at the 1 % level of significance. The teal continued to flap steadily as the tunnel tilt angle was varied from -1 ° (climb) to +6 ° (descent), while the wingbeat frequency declined progressively by about 11 %. In both birds, the plot of wingbeat frequency against air speed in level flight was U-shaped, with small but statistically significant curvature. We identified the minima of these curves with the minimum power speed (Vmp) and found that the values predicted for Vmp, using previously published default values for the required variables, were only about two-thirds of the observed minimum-frequency speeds. The discrepancy could be resolved if the body drag coefficients (CDb) of both birds were near 0.08, rather than near 0.40 as previously assumed. The previously published high values for body drag coefficients were derived from wind-tunnel measurements on frozen bird bodies, from which the wings had been removed, and had long been regarded as anomalous, as values below 0.01 are given in the engineering literature for streamlined bodies. We suggest that birds of any size that have well-streamlined bodies can achieve minimum body drag coefficients of around 0.05 if the feet can be fully retracted under the flank feathers. In such birds, field observations of flight speeds may need to be reinterpreted in the light of higher estimates of Vmp. Estimates of the effective lift:drag ratio and range can also be revised upwards. Birds that have large feet or trailing legs may have higher body drag coefficients. The original estimates of around CDb=0.4 could be correct for species, such as pelicans and large herons, that also have prominent heads. We see no evidence for any progressive reduction of body drag coefficient in the Reynolds number range covered by our experiments, that is 21 600215 000 on the basis of body cross-sectional diameter.

Journal Article↗

PubMed2001

Gliding flight in a jackdaw: a wind tunnel study.

We examined the gliding flight performance of a jackdaw Corvus monedula in a wind tunnel. The jackdaw was able to glide steadily at speeds between 6 and 11 m s(-1). The bird changed its wingspan and wing area over this speed range, and we measured the so-called glide super-polar, which is the envelope of fixed-wing glide polars over a range of forward speeds and sinking speeds. The glide super-polar was an inverted U-shape with a minimum sinking speed (V(ms)) at 7.4 m s(-1) and a speed for best glide (V(bg)) at 8.3 m s(-)). At the minimum sinking speed, the associated vertical sinking speed was 0.62 m s(-1). The relationship between the ratio of lift to drag (L:D) and airspeed showed an inverted U-shape with a maximum of 12.6 at 8.5 m s(-1). Wingspan decreased linearly with speed over the whole speed range investigated. The tail was spread extensively at low and moderate speeds; at speeds between 6 and 9 m s(-1), the tail area decreased linearly with speed, and at speeds above 9 m s(-1) the tail was fully furled. Reynolds number calculated with the mean chord as the reference length ranged from 38 000 to 76 000 over the speed range 6-11 m s(-1). Comparisons of the jackdaw flight performance were made with existing theory of gliding flight. We also re-analysed data on span ratios with respect to speed in two other bird species previously studied in wind tunnels. These data indicate that an equation for calculating the span ratio, which minimises the sum of induced and profile drag, does not predict the actual span ratios observed in these birds. We derive an alternative equation on the basis of the observed span ratios for calculating wingspan and wing area with respect to forward speed in gliding birds from information about body mass, maximum wingspan, maximum wing area and maximum coefficient of lift. These alternative equations can be used in combination with any model of gliding flight where wing area and wingspan are considered to calculate sinking rate with respect to forward speed.

Animals↗

PubMed2002

Fringe-imaging Mach-Zehnder interferometer as a spectral analyzer for molecular Doppler wind lidar.

The theoretical performance of a Mach-Zehnder interferometer used as a spectral analyzer for wind-speed measurement by direct-detection Doppler lidar is presented. The interferometer is optimized for the measurement of wind velocity from the signal that is backscattered by the molecules. In the proposed fringe-imaging Mach-Zehnder (FIMZ) interferometer, a pattern of equally spaced linear fringes is formed and detected by two conventional detector linear arrays. Assuming a pure molecular signal with Gaussian spectral profile, an analytic expression for the standard deviation of the measurement error is obtained and compared with the Cramer-Rao lower bound given by an ideal spectral analyzer (ISA) in the case of shot-noise-limited signal. The FIMZ measurement error is shown to be 2.3 times that of the ISA and is comparable with the error given by previously developed multichannel spectral analyzers that are based on Fabry-Perot interferometers that, in contrast, have the disadvantages of producing unequally spaced circular fringes and requiring dedicated detectors. The optimal path difference for a FIMZ operating at 355 nm is approximately 3 cm. The interferometer is shown to match important lidar beam étendues without significant performance reduction.

Journal Article↗

PubMed2002

Airborne Doppler lidar investigation of the wind-modulated sea-surface angular retroreflectance signature.

Concurrent measurements of sea-surface retroreflectance and associated wind velocity acquired with an airborne CO2 Doppler lidar are described. These observations provide further insight into thermal infrared optical phenomenology of air-sea interface processes, contribute to a greater understanding of radiation transfer between the atmosphere and the hydrosphere, and enable improved models of wind-driven ocean-surface stress applicable to other remote sensing applications. In particular, we present lidar measurements of azimuthally anisotropic reflectance behavior and discuss the implications to current understanding of sea-surface optical properties.

Journal Article↗

PubMed2005

Measurements of the infrared emissivity of a wind-roughened sea surface.

Spectral statistical-analysis techniques were developed and applied to high-spectral-resolution infrared measurements of the sea surface. The effective incidence angle of a ship-borne instrument in typical at-sea conditions was found to introduce errors of up to 0.7 K in sea-surface temperature retrievals at a 55 degrees view angle. The sea-surface emissivity was determined over the 8-12-microm window at view angles of 40 degrees and 55 degrees and at wind speeds up to 13 ms(-1). The emissivity was found to increase in magnitude with increasing wind speed, rather than decrease, as predicted by widely used parameterizations. Use of these parameterizations can cause significant bias in remote sensing of sea-surface temperature in noncalm conditions.

Journal Article↗

PubMed2005

Ultraviolet high-spectral-resolution Doppler lidar for measuring wind field and aerosol optical properties.

An ultraviolet incoherent Doppler lidar that incorporates the high-spectral-resolution (HSR) technique has been developed for measuring the wind field and aerosol optical properties in the troposphere. An injection seeded and tripled Nd:YAG laser at an ultraviolet wavelength of 355 nm was used in the lidar system. The HRS technique can resolve the aerosol Mie backscatter and the molecular Rayleigh backscatter to derive the signal components. By detecting the Mie backscatter, a great increase in the Doppler filter sensitivity was realized compared to the conventional incoherent Doppler lidars that detected the Rayleigh backscatter. The wind velocity distribution in a two-dimensional cross section was measured. By using the HSR technique, multifunction and absolute value measurements were realized for aerosol extinction, and volume backscatter coefficients; the laser beam transmittance, the lidar ratio, and the backscatter ratio are derived from these measurements.

Journal Article↗

PubMed2006

Laser-optical fiber Bragg grating anemometer for measuring gas flows: application to measuring the electric wind.

A novel laser-optical fiber Bragg grating anemometer (FBGA) has been devised for measuring the speed of a moving gas in the range 0-1.5 m s(-1). As a test, the FBGA was applied to measuring the speed of the electric wind generated in the particularly harsh, high-voltage environment of a dc, negative-polarity, partial (corona) discharge in atmospheric air. The instrument proved more stable and yielded an order-of-magnitude improvement in sensitivity (deltav approximately 4 x 10(-3) ms(-1)) compared with other optical-fiber-based anemometers. On-axis wind speeds ranging from zero to 1.1 m s(-1) were measured in the vicinity of the corona discharge.

Journal Article↗

PubMed1985

Pulmonary function in singers and wind-instrument players.

Previous studies suggest that pulmonary function of singers and wind-instrument players may be better than normal control subjects due to breath-control training; however, prior studies were poorly controlled or limited in scope. In the present study, we compare 34 singers and 48 wind instrumentalists with a control group of 31 string or percussion instrumentalists using a pulmonary questionnaire, measurements of inspiratory and expiratory pressures, and spirometry. We found no significant difference between groups in maximum voluntary ventilation, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), mean forced expiratory flow during the middle half of the FVC, the FEV1/FVC, peak expiratory pressure, or peak inspiratory pressure, independently or when corrected for age, sex, height, weight, years performing, smoking, presence or absence of cough, or sputum production. Smoking correlated negatively with measurements of pulmonary function in all groups. There was evidence of a heightened awareness of health among singers, who exercised more and smoked less than their colleagues. The differences in health habits may account in part for the myth of improved pulmonary volumes among singers.

Adult↗

PubMed2005

[Clinical study of wind-warm and pulmonary heat syndrome treated with integrated traditional Chinese and Western medicine].

OBJECTIVE: To investigate the clinical effectiveness of Toubiao Qingfei (expelling exterior evil and clearing lung) Decoction (TBQFD) on wind-warm and pulmonary heat syndrome. METHODS: Forty-six subjects were randomized into treatment group and control group. Patients in the control group were treated with Western medicines, while patients in the treatment group were treated with Western medicines and TBQFD. The therapeutic effects and improvement of symptoms in both groups were observed. RESULTS: The durations of fever, cough and absorption of pulmonary inflammatory focus in the treatment group were 1.52, 3.52 and 6.25 days respectively, which were significantly shorter than those in the control group (P<0.05). CONCLUSION: TBQFD can improve the symptoms, such as fever and cough, and can promote the absorption of infection and shorten the clinical course of wind-warm and pulmonary heat syndrome.

Adult↗

PubMed1989

[Laryngeal movements during wind instruments play].

Historically, the concern of wind instrumentalists has been diaphragm control and embouchure. Laryngeal movement during "blow" has been overlooked or neglected by wind musicians. It has been said that musical tone has to be produced by the resonances of the player's air column by opening his larynx during blow. In the present study, fiberscopic observations of the larynx during blow revealed that musical tones were played with adducted vocal cords. Narrowed glottis appeared to control the airflow of the blow. Persons who could not make musical tone blew with open glottis. Vibrato was also made by rhythmic open and narrowing movements of the glottis. The authors concluded that the larynx regulates the airflow of the "blow". The authors postulated that the embouchure might be important as the receptor of the airflow rather than controlling the movement for "blow".

Adolescent↗

PubMed2000

[A further research on physiopathological basis of "Liver Yang Forming Wind Syndrome"].

The multiple experimental parameters of different aspects in this study were determined in the patients with "Liver Yang Forming Wind Syndrome (LYFWS)", "Qi Deficiency Blood Stagnation Syndrome (QDBSS)" and "Yin Deficiency Forming Wind Syndrome (YDFWS)". The results showed that cerebral hemorrhage was similar to cerebral infarction in almost all parameters and the two diseases were with LYFWS. It was found that there were several characteristics in LYFWS, i.e. 1. Hyperfunction of sympathetic adrenal medullary system. 2. Hypotriiodothyroidoglobulin syndrome. 3. The marked changes of the active substance regulating vessel smooth muscle function. 4. The increased inflammatory medicators. The pathophysiological parameters in patients with QDBSS were the same as those with YDFWS, but the changes of QDBSS and YDFWS weRe milder than those of LYFWS.

6-Ketoprostaglandin F1 alpha↗

PubMed2004

Wind tunnel evaluation of several tracer and collection techniques for the measurement of spray drift.

In the history of pesticide drift measuring techniques, different tracers and a lot of different collection techniques have been used. At the start of a new Flemish project 'Protecting the Flemish environment against drift - The importance of drift-reducing techniques', wind tunnel tests have been executed to select the most efficient tracer and collection technique. As tracer types a fluorescent tracer Renaissance W15, 2 different chelates, a NaCl-solution and a fungicide Tolylfluanide were used. 2 different collection techniques were tested: drains incorporated in the wind tunnel floor filled with filter paper and filled with cloths. The recovery of the different tracers combined with the 2 collection materials was calculated. The advantages and disadvantages of the tracers and collection materials are enumerated in this article.

Air Pollutants↗

PubMed2005

The brain-resuscitation acupuncture method for treatment of post wind-stroke mental depression--a report of 45 cases.

In order to observe the therapeutic effects of the brain-resuscitation acupuncture method for post wind-stroke mental depression, 90 such cases were randomly divided into two groups, each consisting of 45 cases. For the treatment group, the brain-resuscitation acupuncture method was adopted, with Neiguan (PC 6), Renzhong (GV 26), Sanyinjiao (SP 6), Baihui (GV 20), and Shenmen (HT 7) selected as the main points. For the control group, oral medication of Fluoxetine was prescribed. Therapeutic effects and changes in the HAMD integrals of the two groups were observed. The total effective rate in the treatment group was 77.7%, and that in the control group was 75.1%, showing no significant difference between the two groups (P>0.05). The average effect starting time of the treatment group was 11.58 +/- 4.89 days, while that of the control group was 15.96 +/- 6.50 days, showing a significant difference between the two groups (P<0.05). It can be concluded that for the post wind-stroke mental depression, the brain-resuscitation acupuncture method may show a good and quicker therapeutic effect with no side effects as compared with pharmacotherapy.

Acupuncture Therapy↗

PubMed1991

[Video-endoscopic findings in playing various wind instruments].

The function of the larynx and tongue of 15 subjects playing different wind instruments was examined. Whichever instrument was played, no variations of the vocal cord positions were found. A sustained note produced by the singing voice, or by playing an instrument, or by singing synchronously was observed by stroposcopy. Laryngeal functions did not change between these three types of use of the larynx. Vibrato was indirectly produced by the vocal cords. Laryngeal disorders influence the playing of wind instruments and the use of the singing voice.

Diaphragm↗