New method for simultaneous gas and aerosol retrievals from space limb-scanning spectral observation of the atmosphere

This study concerns the development of a new inversion method for simultaneous gas and aerosol retrievals in the upper layers of the atmosphere from limb-viewing multiwavelength-transmission infrared measurements. In this method, concentrations of gas species such as O3, NO2, HNO3, N2O, CH4, and H2O, and spectral dependences of the aerosol extinction coefficient are retrieved simultaneously. When this is done, smoothness constraints on the desired spectral dependencies of the aerosol extinction coefficient are used as an a priori assumption. The method is used in the treating of synthetic transmission spectra of the Improved Limb Atmospheric Spectrometer, which is based on the solar occultation technique and was on board the Advanced Earth Observing Satellite. A set of numerical tests shows the efficiency of the method.     

Tropospheric aerosol optical properties derived from lidar, sun photometer, and optical particle counter measurements

Tropospheric aerosols have been observed for the period from November 1990 to April 1992 with a lidar, a sun photometer, and an optical particle counter. Variations of aerosol optical thickness derived from the lidar and the sun photometer data and measurements are presented. The simultaneous measurements of these instruments also allowed us to estimate the extinction-to-backscatter ratio (S(1)), which ranged from 20 to 70. Comparison of optical thicknesses derived from both instruments clearly shows the effect of Mt. Pinatubo's eruption and the temporal variation of optical thickness in the stratosphere over 12 km. The possible range of the complex refractive index for the columnar mean aerosols can be deduced from the probable range of S(1) derived by the use of an S(1) diagram as a function of complex refractive index (m). The imaginary part of m can be estimated provided that the real part of m is known.     

Passivity-based robust feedback control for non-linear systems with input dynamical uncertainty

This paper addresses the robust feedback control problem for a class of non-linear systems with uncertain input dynamics. The main objective is to develop a passivity-based systematic design approach for this kind of uncertain system. First, a passivity condition is presented for a non-linear system in feedback interconnection form, and then it is shown that with the help of this condition, a state feedback control law can be designed to render the uncertain system passive. Moreover, the extensions of the passivation controller are investigated in two cases where the uncertainty allows unknown control direction and there exists the external disturbance, respectively. It will be shown that an adaptive controller with a Nussbaum-type function can be incorporated into the passivation controller to deal with the unknown control direction and the L ₂-gain performance can be achieved by gain re-assignment of the passivation controller. Finally, a numerical example is given to demonstrate the proposed approach.     

GRAPES-3—A high-density air shower array for studies on the structure in the cosmic-ray energy spectrum near the knee

The change in the spectral index from about -2.7 to -3.1 at 3×10¹⁵ eV in the all-particle energy spectrum of primary cosmic rays is very significant for learning about the nature of cosmic sources of ultra-high energy particles and their acceleration and propagation in the galactic disk. Any observation of a fine structure in the spectrum would be important for improving our understanding of these physical processes. The GRAPES-3 air shower array has been designed to achieve higher precision in determination of various shower parameters to enable observation of any fine structure in the energy spectrum, if it exists. The details of the shower detectors, shower trigger and the data acquisition system are presented here along with estimates of trigger efficiencies from Monte Carlo simulations for primary photons (γ-rays) and several nuclei.     

Antihypertensive mechanism of a peptide-enriched soy sauce-like seasoning: the active constituents and its suppressive effect on renin-angiotensin-aldosterone system

We previously reported that a peptide-enriched soy sauce-like seasoning called fermented soybean seasoning (FSS) demonstrated antihypertensive effects both in spontaneously hypertensive rats (SHR) and Dahl salt-sensitive rats. Angiotensin I-converting enzyme (ACE) inhibitory substances (9 kinds of dipeptides and a nicotianamine) were identified from FSS. In the present study, we clarified the mechanisms underlying the antihypertensive effects of FSS in SHR. FSS was divided into the nicotianamine fraction and the peptide fraction. The peptide fraction was found to exert a more prevalent antihypertensive effect than the nicotianamine fraction in SHR. Among the peptides, we identified Gly-Tyr and Ser-Tyr as the 2 primary substances in FSS that contributed to the antihypertensive effect in SHR. These peptides were neither degraded by acid nor gastrointestinal proteases, and were absorbed into the circulating blood. FSS (2000 mg/kg) exerted ACE inhibitory activity in the lung of rats and provided a decrease (P= 0.0067) in the level of serum aldosterone after a single oral administration in SHR, resulting in the antihypertensive effect. The antihypertensive mechanism was found to be similar to therapeutic ACE inhibitors and other food-derived ACE inhibitory peptides, which are in wide use and are recognized as safe.     

Electrically Conductive CNT-Dispersed Silicon Nitride Ceramics

Carbon nanotube (CNT)-dispersed Si₃N₄ ceramics with electrical conductivity were developed based on the lower temperature densification technique, in which the key point is the addition of both TiO₂ and AlN as well as Y₂O₃ and Al₂O₃ as sintering aids. This new ceramic with a small amount of CNTs exhibits very high electrical conductivity in addition to high strength and toughness. Since Si₃N₄ ceramics with Y₂O₃–Al₂O₃–TiO₂–AlN were originally used as a wear material, electrically conductive Si₃N₄ ceramics are expected to be applied for high-performance static-electricity-free bearings for aerospace and other high-performance components.     

SOLVENT EXTRACTION EQUILIBRIA OF LEAD(II) WITH ACIDIC ORGANOPHOSPHATE AND PHOSPHONATE

Distribution equilibria of lead(II) in the extraction with di(2-ethylhexyl)phosphoric acid and 2-ethylhexyl 2-ethylhexylphosphonic acid in toluene from aqueous ammonium nitrate solutions were measured at 303 K to elucidate the concentration dependencies of the reactant species on the distribution ratio. It was found that lead(II) is extracted as the mononuclear complex, PbR₂2HR, with the former extrac-tant while it is extracted not only as the complex, PbR₂2HR, but also as the complex, Pb(NO₃)R;HR, accompanied by simultaneous transfer of nitrate anion with the latter ex-tractant. The extraction equilibrium constants of these complexes were evaluated as well as the stability constants of lead(II) -nitrato complexes, Pb(NO₃)⁺, Pb(NO₃)₂and Pb(NO₃)^? ₃.     

Polymeric chiral crown ethers

Summary Copolymerizations of (S)-3,3-dimethyl-2,2-bis[2-(2-vinyloxyethoxy)ethoxy]-1, 1-binaphthyl (S-MVN) or 1,3:4,6-di-O-benzylidene-2,5-bis-O-[2-(2-vinyloxyethoxy)ethyl]-d-mannitol (D-BVM) with isobutyl vinyl ether (IBVE) were carried out with BF₃·OEt₂ in CH₂Cl₂ at 0 °C. The copolymers obtained were soluble in CHCl₃ and THF, and consited of (S)-binaphtho-21-crown-6 or d-manno-21-crown-6 units and IBVE, i.e., poly(S-DVN-co-IBVE) and poly(D-BVM-co-IBVE). These host copolymers dominantly formed complexes with l-phenylglycine methyl ester, whose properties were similar to those for homopolymers of S-MVN and D-BVM.Part 8: H. Hashimoto, T. Kakuchi, O. Haba, K. Yokota: Macromolecules 25 1828 (1992)     

Electroplasticity memory devices using conducting polymers and solid polymer electrolytes

Erasable memory devices are fabricated by the combination of a conducting polymer and solid polymer electrolyte. The former is used as a memory channel and the latter as an electrolyte medium. The channel conductivity can be controlled over 3-4 orders of magnitude by electrochemical doping through a writing electrode. The response time, depending on the writing voltage, is several seconds. The characteristics of the memory device are discussed.     

Simultaneous stratospheric gas and aerosol retrievals from broadband infrared occultation measurements

The inversion method for simultaneous gas (O3, NO2, HNO3, N2O, CH4, H2O, CFC-11, CFC-12, N2O5, and ClONO2) and aerosol retrievals from broadband continuous IR spectra of occultation measurements is described. Both gas and aerosol physical modeling with consideration of the multicomponent character of aerosol and polar stratospheric clouds (PSCs) are used to minimize the difference between measured and modeled transmittance spectra under smoothness constraints imposed on particle-size distributions for each PSC component and positive constraints on all gas and aerosol parameters. The method is tested by numerical simulations in which synthetic occultation measurements inherent to the improved limb atmospheric spectrometer are used. The study reveals that the method has significant advantages over other approaches based on offset or gas-window-channel aerosol correction for accurate gas retrievals and provides additional information on the particle-size composition, volume density, and chemical component character of PSCs.