25,254 research outputs found
Processing options for gold-tellurides
No full textY. Zhang, J. Zhang, H. Wang, W. Weng, Y. Ngothai, W. Liang, J. Zhao, Y. Mei, M. Xie, Y. Jia, F. Gao, H. Ma, P. Liu and W. Richmondhttp://www.wcce8.org/techsched/00000385.ht
Corrugated horn with stable phase center for Ka-band compact antenna test range measurement systems
No full textIn this article, a corrugated horn feed antenna with a stable phase center is designed for the millimeter wave compact antenna test range (CATR). The calculation method of the phase center of a horn is analyzed in this article. The 45°-plane phase center is used as the combined phase center of the horn in order to perform the phase center calculation only once, thus faster, and to optimize the phase performance more conveniently. By adding an absorbing material surrounding the edge of the outer surface of the horn, the irregular currents on the outer surface of the horn are suppressed, thus achieving a more stable phase center. The absorbing material can also reduce the radar cross section of the antenna. The designed corrugated horn works in the 24–40 GHz wide band with the following performances: the deviation of the phase center in the working frequency band is less than ±0.25 mm, the phase variation within a ±30° beam width is less than ±2.5°. Moreover, the measured return loss is lower than −10 dB, the measured gain is 8–12 dBi, and the measured cross-polarization level is less than −30 dB. The beamwidth is about 56°–70° in the whole band, and the beamwidth difference between different planes is less than 5°. The achieved targets listed above makes the proposed corrugated horn suitable for very precise antenna measurements in CATR systems
An 1.7–2.7 GHz all-weather broadband High-gain antenna with W-shape reflector for maritime communications
No full textAn all-weather broadband high-gain antenna for maritime communication applications is developed in this paper. The proposed antenna, which is devised from the perspective of hydrodynamics, hydrostatics, and electromagnetic performance, is based on combining a wideband high-efficiency electromagnetic radiation structure (WHEMS) and a W reflector to achieve both superior mechanical and electrical performances. The proposed W reflector has a fractional 3-dB gain bandwidth of 150 % for a three-dipole array radiator, which is 53 % and 90 % larger than the gain bandwidth of the classic planar reflectors and the corner reflectors, respectively. To better adapt to the harsh marine environment and its potential IoT demands, the proposed antenna is devised to be light weight, small wind loading, high mechanical strength, small size, low cost, lightning-strike resistant, and consistent coefficient of thermal expansion, without the need of any radome. Two W reflector prototypes are ideated and manufactured from sheets and metal rods, denoted as Antenna I and Antenna II, respectively. Both the antennas realize 10–13 dBi gains in a 45 % bandwidth (1.7–2.7 GHz) with the sidelobe level lower than 12 dB, and a front-to-back ratio larger than 18 dB. The anti-deformation property of the proposed Antenna II is demonstrated to be 3.8 times higher than that of the classic Yagi antenna to be used in an open-ocean environment with a typhoon of force 1
Landsat MSS classification of fire fuel types in Wood Buffalo National Park, northern Canada
No full textJ1: Global Ecology & Biogeography Letters; M3: Article; Milne, David Franklin, Steven E. Wilson, Bradley A. Ghitter, Geoff Heathcott, Mark McCaffrey, Thomas M. Ow, Charlotte F. Y.; Source Information: Mar1994, Vol. 4 Issue 2, p33; Subject Term: FOREST fires; Author-Supplied Keyword: Canada (Wood Buffalo National Park); Author-Supplied Keyword: Forest fire; Author-Supplied Keyword: Fuel type classification; Author-Supplied Keyword: Landsat data; Number of Pages: 0p; Document Type: Articl
The effects of epinephrine on outcomes of normothermic and therapeutic hypothermic cardiopulmonary resuscitation
No full textOBJECTIVE:
To investigate the effects of epinephrine when administered during either normothermic or therapeutic hypothermic cardiopulmonary resuscitation on postresuscitation myocardial and cerebral function and survival.
DESIGN:
Prospective, randomized, placebo-controlled experimental study.
SETTING:
University-affiliated animal research laboratory.
SUBJECTS:
Thirty-two healthy male Sprague-Dawley rats.
INTERVENTIONS:
Ventricular fibrillation was induced and untreated for 8 mins. The animals were then randomly assigned to one of four groups: normothermic placebo control; normothermic epinephrine; hypothermic placebo control; and hypothermic epinephrine. Hypothermia was initiated coincident with the start of cardiopulmonary resuscitation. The blood temperature was reduced and maintained at 32 ± 0.2°C and continued for 4 hrs after resuscitation. Normothermic animals were maintained at 37 ± 0.2°C. Either placebo or epinephrine (20 μg/kg) was administered 5 mins after the start of cardiopulmonary resuscitation and 3 mins before defibrillation.
MEASUREMENTS AND MAIN RESULTS:
Postresuscitation cardiac output, ejection fraction, and myocardial performance index were measured hourly for 4 hrs after resuscitation; neurologic deficit scores were measured daily for 7 days, and durations of survival were observed for up to 3 mos. Except for three normothermic control animals, all animals were resuscitated. When epinephrine was administered during normothermic cardiopulmonary resuscitation, postresuscitation myocardial function was severely impaired when compared with the normothermic control group. However, postresuscitation myocardial function was significantly better in animals treated with epinephrine during hypothermic cardiopulmonary resuscitation when compared with hypothermic controls. This was associated with significantly fewer postresuscitation ventricular arrhythmias, less ST-segment elevation, better postresuscitation neurologic deficit scores, and longer duration of survival.
CONCLUSIONS:
Epinephrine, when administered during normothermic cardiopulmonary resuscitation, significantly increases the severity of postresuscitation myocardial dysfunction and decreases the duration of survival. These detrimental effects of epinephrine, however, no longer exist when it is administered during therapeutic hypothermic cardiopulmonary resuscitation
A Novel Thermo-tolerant a-Amylase, CMCase, and Protease Produced by Multi-functional Thermo-tolerant Phosphate-solubilizing Microbes
No full textThe generalized Liénard polynomial differential systems x'=y,y'= -g(x) - f (x)y with deg g = deg f 1 are not Liouvillian integrable
Full text linkAgraïments: The second author was supported by Portuguese National Funds through FCT - Fundação para a Ciência e a Tecnologia within the project PTDC/MAT/117106/2010 and by CAMGSD (PEst-OE/EEI/LA0009/2013)We prove the nonexistence of Liouvillian first integrals for the generalized Li\'enard polynomial differential systems of the form x' = y, y'=-g(x)-f(x)y, where g(x) and f(x) are arbitrary polynomials such that g = f 1
Toxicity of Fusarium mycotoxins on growth performance, immune response and efficacy of a mycotoxin degrading enzyme in pigs
No full textTricalcium Phosphate-solubilizing with Three Media by Thermo-tolerant Phosphate- solubilizing Bacterial Isolates
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