Quantitative Multi-Element Analysis in Soil Using 532 nm and 1064 nm Lasers in LIBS Technique

Plasma Chemistry and Plasma Processing - Laser-induced breakdown spectroscopy (LIBS) has been considered a promising tool for agricultural analysis in the recent years due to its advantages over...     

The synthesis and thermal property of sodium cyclo-octaphosphate

Sodium cyclo-octaphosphate heptahydrate, (NaPO₃)₈ · 7H₂O, has been made by heating lead cyclo-tetraphosphate at 340°C, dissolving the thermal product in a 3% aqueous solution of tetrasodium ethylene-diaminetetraacetate, and then crystallizing it by addition of sodium chloride and acetone to the solution. When the cyclo-octaphosphate was heated up to 400°C, it decomposed to produce phosphates with both shorter and longer chain lengths. A main product at 300° to 350°C was sodium cyclo-triphosphate, and the thermal product melted at about 630°C.     

Growth of corundum single crystals by the top-seeded solution growth technique (TSSG)

Single crystals of corundum were grown by the top-seeded solution growth technique from a cryolite, Na₃AlF₆, solvent. The relationship between the growth rate (mg/h) of a crystal and the temperature difference (= supersaturation) or the rotation rate of a seed crystal was investigated, and optimum growth conditions for obtaining single crystals with good quality are discussed.     

Vibrational properties of hexagonal boron nitride: inelastic X-ray scattering and ab initio calculations

The phonon dispersion relations of bulk hexagonal boron nitride have been determined from inelastic x-ray scattering measurements and analyzed by ab initio calculations. Experimental data and calculations show an outstanding agreement and reconcile the controversies raised by recent experimental data obtained by electron-energy loss spectroscopy and second-order Raman scattering.     

Long-lived ultrafast spin precession in manganese alloys films with a large perpendicular magnetic anisotropy

Spin precession with frequencies up to 280 GHz is observed in Mn(3-δ)Ga alloy films with a perpendicular magnetic anisotropy constant K(u)～15 M?erg/cm(3). The damping constant α, characterizing macroscopic spin relaxation and being a key factor in spin-transfer-torque systems, is not larger than 0.008 (0.015) for the δ=1.46 (0.88) film. Those are about one-tenth of α values for known materials with large K(u). First-principles calculations well describe both low α and large K(u) for these alloys.     

Electron paramagnetic resonance imaging using magnetic-field-gradient spinning

A novel X-band CW EPR imaging has been developed using magnetic-field-gradient (MFG) spinning to obtain spatial distributions of electron paramagnetic species. Spinning MFG EPR imaging for 65 projection spectra required just 55 s while conventional imaging took 11 min 40 s, that is, the acquisition time for the new system is one order of magnitude shorter than that for conventional EPR imaging. Spinning MFG EPR imaging allows one to measure reconstructed images in an interactive manner where resolution and condition can be changed quickly.     

ESR study of amorphous Ge-S and Ge-S-Ag in bulk and film forms

The assignment of ESR signals in Ge-S glasses to certain types of defect has been proposed. The origin of the signal is two types of Ge dangling bond for GeS_x bulks with x < 2, and is two types of S dangling bond for those with x > 2. In the film sample with x > 2, the ESR center density is largely enhanced, and Ge dangling bonds exist in addition to S dangling bonds. The decrease of the ESR center density by Ag doping is explained by the reduction of randomness in the glass structure.     

In situ observation of photoinduced refractive-index changes in filaments formed in glasses by femtosecond laser pulses

We investigated the relationship between the formation of filaments and local refractive-index changes induced by femtosecond laser pulses in silica glass. In situ observation revealed that the location of a filament coincided with that of the refractive-index change. Observation also showed that the region of refractive-index change was elongated toward the upstream direction of the laser pulses with increasing exposure time. The region of refractive-index change was several hundred micrometers long, and its diameter was smaller than 2 mum. The refractive-index change was confirmed by two of three different methods to be as large as 0.8 x 10(-2).     

Pushing exercise program to correct glottal incompetence

A voice therapy program using pushing exercises to correct glottal incompetence is described. The program utilizes various types of instrumentation to determine whether or not a given patient is likely to benefit from the treatment. The program also provides feedback of target voices. Three cases with incomplete glottal closure and subsequent vocal dysphonia characterized by an asthenic breathy quality are used to illustrate the program. Details of the program, termination criteria, and problems and precautions learned from treating 29 patients over a 3-year period are presented.     

Dielectric constants of adsorbed CO on Cu and Ag

Adsorption of CO on evaporated Ag and Cu films was studied by ellipsometry and resistivity measurements. Changes in ellipsometric angles δΔ and δψ due to adsorption of CO were analyzed by an improved linear approximation of the stratified layer model of adsorption. Adsorption of CO on Cu induced a 23% increase in the relative resistivity change (δR/R) which was proportional to δψ, while adsorption of CO on Ag induced a 1% increase without the proportionality. The dielectric constant of CO adsorbed on Ag is $\text{?}{}_1\text{= 2.2?0.7i}$ at λ = 1152 nm in comparison to ?₁ = 2.1 for gas phase CO; that of CO on Cu is $\text{?}{}_1\text{= ?4.8 ? 8.5i}$, which is consistent with the prediction by the Bennett and Penn theory. The large difference in $\text{}\text{?}$ge₁, of adsorbed CO on Ag and Cu is understood in terms of the energy level of the 2 π molecular orbital of adsorbed CO relative to the Fermi level. A possibility of adlayer plasmon excitation is discussed.