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Maximum Gain (maximum + gain)

Distribution by Scientific Domains

Engineering	60%

Selected Abstracts

Early Detection Of Diminished Baroreflex Sensitivity In Diabetic Patients Without Evidence Of Cardiovascular Autonomic Neuropathy

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2000
D Ziegler
Diabetic cardiovascular autonomic neuropathy (CAN) carries an increased risk of mortality. Decreased baroreflex sensitivity (BRS) has been identified as a predictor of increased mortality following myocardial infarction. We evaluated spontaneous BRS in 39 healthy control subjects (C: age (mean ± SEM): 41.5 ± 1.9 years) and 116 diabetic patients (64% Type 1, 36% Type 2; age: 45.8 ± 1.4 years; diabetes duration: 16.9 ± 1.0 years; HbA1c: 9.2 ± 0.2%) using cross-spectral analysis between systolic blood pressure and heart rate in the low-frequency (LF) and high-frequency (HF) bands as well as time domain (sequence) analysis in the supine and standing positions over 10 min. According to previously suggested definitions based on autonomic function tests (AFTs), 36 patients had definite CAN (CAN+: 3 of 7 indices abnormal), 13 had borderline CAN (CAN[+]: 2 of 7 indices abnormal), and 64 had no evidence of CAN (CAN,: 1 of 7 indices abnormal). Maximum gain in cross-spectral LF band (standing) was significantly reduced in CAN, as compared with C (5.2 ± 0.4 vs. 7.2 ± 0.8 ms/mmHg, p < 0.05). Moreover, maximum gain in cross-spectral HF band was significantly lower in CAN, than in C (supine: 12.0 ± 1.2 vs. 17.9 ± 2.5 ms/mmHg, p < 0.05; standing: 4.9 ± 0.5 vs. 8.7 ± 1.0 ms/mmHg, p < 0.05). The slope of the regression line between defined increases or reductions in systolic blood pressure and R-R intervals was significantly reduced in CAN, compared to C (supine: 10.6 ± 0.7 vs. 14.2 ± 1.6 ms/mmHg, p < 0.05; standing: 5.6 ± 0.4 vs. 8.1 ± 0.7 ms/mmHg, p < 0.05). Similar differences were obtained when comparing the CAN, and CAN[+] groups, the latter showing significantly reduced BRS by both techniques (p < 0.05). In contrast, no such differences were noted when comparing the CAN[+] and CAN+ groups. In conclusion, reduced spontaneous baroreflex sensitivity is an early marker of autonomic dysfunction at a stage when autonomic function tests do not yet indicate the presence of CAN, while cases with borderline CAN show a degree of BRS abnormality that is comparable to the level seen in definite CAN. Prospective studies are needed to evaluate whether reduced BRS is a predictor of mortality in diabetic patients. [source]

High-Performance Organic Single-Crystal Transistors and Digital Inverters of an Anthracene Derivative

ADVANCED MATERIALS, Issue 36 2009
Lang Jiang
Single-crystal disks of di(phenylvinyl) anthracene, micro- or nanometer-sized and flexible, are produced by physical vapor transport. Subsequently, single- crystal transistors are fabricated by the organic ribbon mask method and integrated to produce high-performance inverters. The mobility of the transistors, the mobility anisotropy along different crystal axes of the disks, and the maximum gain of the inverters are reported. [source]

A simplified quasi-two-dimensional model for gain optimization in carbon dioxide gasdynamic lasers (GDL)

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 11 2002
A. R. Bahrampour
Abstract In this paper a simplified quasi-two-dimensional model for small signal gain optimization in gasdynamic laser is introduced. In order to obtain a homogeneous medium with maximum optical gain in the active medium, by nozzle shape formation, the shock occurrence position is controlled and is postponed to some point behind the laser active medium. Then the method of calculus of variation is used to find the supersonic part of the nozzle of a gasdynamic laser with maximum gain in the active medium. The interesting result is that the supersonic part of such a nozzle consists of a wedge as the accelerating part of the nozzle, a smooth surface for the uniformization, and finally a channel for the relaxation of the medium. (The middle section is characterized as the geometrical locus of points whose characteristic curves are concurrent at a certain point.) It is also shown that, overlooking a minor difference in the gain, the nozzle can be chosen to be a shock free one with the ultimate optical uniformity. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Changes in body mass and organ size during wing moult in non-breeding greylag geese Anser anser

JOURNAL OF AVIAN BIOLOGY, Issue 6 2005
Anthony D. Fox
The "cost-benefit" hypothesis states that specific body organs show mass changes consistent with a trade-off between the importance of their function and cost of their maintenance. We tested four predictions from this hypothesis using data on non-breeding greylag geese Anser anser during the course of remigial moult: namely that (i) pectoral muscles and heart would atrophy followed by hypertrophy, (ii) leg muscles would hypertrophy followed by atrophy, (iii) that digestive organs and liver would atrophy followed by hypertrophy and (iv) fat depots be depleted. Dissection of geese captured on three different dates during wing moult on the Danish island of Saltholm provided data on locomotory muscles and digestive organ size that confirmed these predictions. Locomotory organs associated with flight showed initial atrophy (a maximum loss of 23% of the initial pectoral muscle mass and 37% heart tissue) followed by hypertrophy as birds regained the powers of flight. Locomotory organs associated with running (leg muscles, since geese habitually run to the safety of water from predator-type stimuli) showed initial hypertrophy (a maximum gain of 37% over initial mass) followed by atrophy. The intestines and liver showed initial atrophy (41% and 37% respectively), consistent with observed reductions in daily time spent feeding during moult, followed by hypertrophy. The majority of the 22% loss in overall body mass (mean 760 g) during the flightless period involved fat utilisation, apparently consumed to meet shortfalls between daily energetic needs and observed rates of exogenous intake. The results support the hypothesis that such phenotypic plasticity in size of fat stores, locomotor and digestive organs can be interpreted as an evolutionary adaptation to meet the conflicting needs of the wing moult. [source]

Early Detection Of Diminished Baroreflex Sensitivity In Diabetic Patients Without Evidence Of Cardiovascular Autonomic Neuropathy

Efficient and high-gain aperture coupled superstrate antenna arrays for 60 GHz indoor communication systems

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010
Hamsakutty Vettikalladi
Abstract Efficient and high-gain aperture coupled patch antenna arrays with superstrate at 60 GHz are studied and presented. It is noted that adding a superstrate with a specific size will induce a significant effect on antenna gain and radiation patterns. This capability is applied on the design of 2 × 2 and 4 × 4 arrays for high-gain application. The maximum measured gain of a 2 × 2 superstrate antenna array is 16 dBi with an efficiency of 63%, which is 4 dB higher than that of a classical 2 × 2 array at 60 GHz. The 2:1 measured voltage standing wave ratio (VSWR) bandwidth is 6.8%. Also the maximum gain measured for a 4 × 4 superstrate antenna array is found to be 19.7 dBi with an estimated efficiency of 51%. The radiation patterns are found to be broadside all over the frequency band with very low back radiation. Hence aperture coupled superstrate antenna array is a good candidate for high-efficient high-gain application at 60 GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2352,2356, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25455 [source]

Low-cost surface-reduction technique for RFID reader antennas

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2010
Matthieu Egels
Abstract A low-cost technique for surface reduction of patch antennas is presented. It is based on the slow wave phenomenon. To create slow wave, a frequency selective surface has been burned on the ground plane of a patch antenna. With this technique, a patch antenna has been designed. An antenna for RFID reader at 915 MHz has been designed and simulated. It uses a 1.6-mm-thick FR4 epoxy substrate (,r = 4.5 h = 1.6 mm tan (,) = 0.02) measures 61 mm × 65 mm. His maximum gain is 2 dB. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1469,1471, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25241 [source]

Low cost ultra wideband amplifier in 0.35 ,m CMOS process

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2008
Kuldip N. Modha
Abstract A two stage ultra wideband (UWB) amplifier is presented. This amplifier incorporates multiple bandwidth enhancing techniques and is implemented in Austria micro systems (AMS) 0.35 ,m CMOS process technology. The amplifier consumes 39.5 mW of power, exhibits a maximum gain of 13 dB, has input and output reflections below ,9 and ,10 dB, respectively over a ,3 dB bandwidth of 4 GHz. The average measured noise figure is 6 dB and 1 dB compression point at 3 GHz is ,12 dBm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1879,1881, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23525 [source]

Wideband and low noise CMOS amplifier for UWB receivers

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2007
Jihak Jung
Abstract An ultra-wideband (UWB) low noise amplifier (LNA) that consists of two common-source and shunt-feedback stages is presented. Measurement results show the maximum gain (S21) of 13.5 dB with the 3-dB band from 1.85 to 10.2 GHz and return losses (S11, S22) of less than ,10 dB from 3 to 11 GHz. In addition, the fabricated LNA achieves the average noise figure (NF) of 4.5 dB from 1.85 to 10.2 GHz. To our knowledge, these are the best measured data up to date for the CMOS LNA. The input-referred third-order intercept point (IIP3) and the input-referred 1-dB compression point (P1dB) are obtained as ,1 dBm and ,9 dBm, respectively, while consuming 13 mW in 0.18 ,m RF CMOS process. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 749,752, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22282 [source]

A compact multiband antenna based on CRLH-TL ZOR for wireless mobile system

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2009
Jeong Keun Ji
Abstract A compact multiband antenna using a composite right/left-handed transmission line (CRLH-TL) zeroth-order resonator (ZOR) for global system for mobile communications (GSM900/1800/1900, 880-960/1710-1880/1850-1990 MHz), wideband code division multiple access (WCDMA, 1920,2170 MHz), and wireless broadband (WiBro, 2.3,2.4 GHz) operations is presented. The proposed antenna having a total volume of 35 mm × 5 mm × 3 mm comprises a lower band ZOR antenna part and an upper band ZOR antenna part. The zeroth-order resonant properties are described and analyzed using dispersion diagrams based on the CRLH-TL ZOR theory and the full-wave simulation. The radiation patterns are the same as the omnidirectional characteristics and the maximum gains are 1.64, 2.47, and 3.32 dBi at 0.92, 1.88, and 2.2 GHz, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2852,2855, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24799 [source]