Analysis of course errors on CVOR antennas (including effects ofmutual coupling between elements)

A VHF omnidirectional radio range (VOR) is a navigation aid radio beacon facility, which provides aircraft with azimuth information relative to the VOR station in question as the origin. In Japan, two types of VOR-the conventional type (referred to as a CVOR) and the Doppler type (referred to as a DVOR)-are currently in use. An element known as the Alford loop antenna (ALA), which changes the loading reactance, is used for the VOR because the horizontally polarized wave and nondirectivity in the horizontal plane are preferred. A VOR antenna consists of a carrier antenna and a sideband antenna-an aircraft receives separate signals from these two antennas and compares them to obtain azimuth information. The mutual coupling between the elements forming the carrier and the sideband antenna affects the directivity of the single elements, resulting in errors in azimuth information. With the mutual coupling between the antenna elements being taken into consideration, a quantitative calculation was made by using the moment method-the results of the calculation made it clear that a loading reactance value of -320 Ω is better to make not mutually coupled elements nondirectional while a loading reactance value of -600 Ω is optimum to minimize the azimuth error of a CVOR     

Sub-50-nm physical gate length CMOS technology and beyond usingsteep halo

Sub-50-nm CMOS devices are investigated using steep halo and shallow source/drain extensions. By using a high-ramp-rate spike annealing (HRR-SA) process and high-dose halo, 45-nm CMOS devices are fabricated with drive currents of 650 and 300 μA/μm for an off current of less than 10 nA/μm at 1.2 V with T_ox^inv =2.5 nm. For an off current less than 300 nA/μm, 33-nm pMOSFETs have a high drive current of 400 uA/μm. Short-channel effect and reverse short-channel effect are suppressed simultaneously by using the HRR-SA process to activate a source/drain extension (SDE) after forming a deep source/drain (S/D). This process sequence is defined as a reverse-order S/D (R-S/D) formation. By using this formation, 24-nm nMOSFETs are achieved with a high drive current of 800 μA/μm for an off current of less than 300 μA/μm at 1.2 V. This high drive current might be a result of a steep halo structure reducing the spreading resistance of source/drain extensions     

Preparation of Copper-Ruby Glasses by Sputtering: The Effect of Atmosphere on the Growth of Copper Particles

Copper-ruby glasses were prepared by the sputtering method and the effect of reducing treatment was examined. The reducing was carried out either during sputtering or heat treatment. Optical absorption was related to the growth of copper particles. The results are summarized as follows: (i) the volume fraction of copper particles in the glasses which are heat-treated in air increases with the addition of hydrogen in the sputtering gas. (ii) The copper particles do not grow larger than 8 nm by heat treatment in reducing atmosphere, whereas they grow as large as 12 nm in air. (iii) Reducing during heat treatment gives a pronounced effect only when sputtering was not carried out under reducing conditions. The origin of these phenomena was also discussed, considering the mechanism of nucleation and growth of copper particles.     

Measurement of aerosol particles by dynamic light scattering-I. effects of non-Gaussian concentration fluctuation in real time photon correlation spectroscopy

Effects of non-Gaussian concentration fluctuations in real time photon correlation spectroscopy were investigated with several sizes of mono-disperse polystyrene latex particles. The non-Gaussian correlation model for a full or a quasi-full (scaled) correlator showed good performance for particle sizing in the case of scaled correlation. The clipped correlation showed an equivalent performance with the scaled correlation except for the case of non-Gaussian fluctuation, where the measured diameter became inaccurate more rapidly with decreasing particle concentration in the scattering volume. The cause of such an instability of PCS in the clipped mode is attributed to baseline fluctuations of the correlogram induced by information loss of the clipped correlator.     

Polarimetric Characteristics of sea ice in the sea of Okhotsk observed by airborne L-band SAR

The Phased-Array L-Band SAR (PALSAR) aboard the Advanced Land Observing Satellite (ALOS) is capable of globally acquiring fully polarimetric data. In order to confirm the ability of L-band polarimetric synthetic aperture radar (SAR) to investigate sea ice before the ALOS launch, we conducted a field experiment using an airborne Polarimetric and Interferometric SAR (Pi-SAR) in the Sea of Okhotsk in 1999. This paper presents the analyzed results of data acquired in that experiment. The extracted polarimetric parameters of several ice types suggested that polarimetric coherences and phase differences between right-right (RR) and left-left (LL) are good candidates for discriminating ice types. The polarimetric anisotropy as well as the beta angle of the first eigenvector calculated in the polarimetric decomposition procedure are alternative parameters that are sensitive to ice type differences. Due to the low depolarization characteristics of open water, it could be discriminated from sea ice by scattering entropy in all incidence angle ranges. From the relation between ice thickness and the polarimetric parameters, we found that backscattering coefficients and vertical (VV) to horizontal (HH) backscattering ratio are highly correlated with ice thickness. Since the ratio is sensitive to ice surface dielectric constants, a simple simulation using the integral equation method surface model was conducted by using the physical parameters of typical sea ice. A two-dimensional ice thickness map was derived from an empirical relation between the VV-to-HH backscattering ratio and ice thickness.     

Theory and characteristics of novel variable reluctance 1X resolver

Although brushless resolvers have been used widely as angular position transducers, they are expensive due to their intricate construction, involving a rotary transformer to supply the exciting coils wound on the rotor poles with the current. It is shown theoretically in this paper that the resolver without rotary transformer or brushes can be realized by simple construction, which consists of the stator core with both 4-poles exciting windings and 2-poles output ones and the rotor core carrying no windings. In this resolver the rotor core has minimum gap at one side and a maximum gap at another side of the diameter. It is characterized by an outer surface form that makes the fluctuation part of gap permeance very in proportion to cos θ, where θ represents the angular position of a point in the air gap with respect to the origin on the rotor, the point of minimum air gap. The method determining the rotor form to embody the aforementioned gap permeance variation is also shown. It has been confirmed not only by simulation but also experiment that the 2-phase output voltages of a model designed based on the theory have sinusoidal waveforms with very small harmonic contents. Moreover, the rotor position detected by processing the output voltages through the conventional resolver/digital converter was within acceptable engineering accuracy.     

An algorithm for the three-dimensional packing problem with asymptotic performance analysis

The three-dimensional packing problem can be stated as follows. Given a list of boxes, each with a given length, width, and height, the problem is to pack these boxes into a rectangular box of fixed-size bottom and unbounded height, so that the height of this packing is minimized. The boxes have to be packed orthogonally and oriented in all three dimensions. We present an approximation algorithm for this problem and show that its asymptotic performance bound is between 2.5 and 2.67. This result answers a question raised by Li and Cheng [5] about the existence of an algorithm for this problem with an asymptotic performance bound less than 2.89. This research was partially supported by FAPESP (proc. 93/0603-1) and by CNPq/ProTeM-CC, project ProComb (proc. 680065/94-6).     

Characterization of cytochrome P450 (CYP3A12) induction by rifampicin in dog liver

We investigated the mechanisms of renal vascular wall thickening in a rat model of N-nitro L-arginine methyl ester (L-NAME)-induced hypertension. To separate the effects of L-NAME-induced hypertension from other effects of nitric oxide (NO) inhibition, we created two models of L-NAME-induced hypertension: both had the same blood pressure level but NO inhibition was moderate in one group (group M) and severe in the other (group S). Urinary excretion of nitrates and nitrites was lower in group S than in group M. Wall thickening and lipid deposition in renal vessels were significantly greater in group S than in groups M. Simple and multiple regression analyses indicated that renal vascular wall thickening was more strongly correlated with lipid deposition than with blood pressure. The number of vessels positive for staining with Sudan black B was negatively correlated with urinary NO excretion. Expression of fibronectin and transforming growth factor-beta was greater in the Sudan black B-positive than in the Sudan black B-negative vessels, suggesting that extracellular matrix production was increased in vessels with lipid deposition. Lipid deposition and increased production of extracellular matrix may contribute to renal vascular wall thickening in L-NAME-induced hypertension. Some mechanisms independent of hypertension play important roles in vascular wall thickening induced by NO inhibition.     

Study on super-long-life cores loaded with minor actinide fuel

Super-long-life fast breeder reactor cores (SLLC) loaded with minor actinide (MA) fuel were designed aiming at continuous operation without refueling during plant lifetime and efficient reduction of MA nuclides (Np, Am and Cm). The feasibility was studied from nuclear and thermal characteristics. As a result, 1000 MWe and 300 MWe SLLCs with small reactivity change and power swing during plant lifetime were found to be feasible. MAs can be confined and transmuted in the reactor during plant life. A 1000 MWe SLLC can transmute MAs of 10 ton which come from 13 light water reactors (1000 MWe).