An isotope study of hot springs in Nagano Prefecture

Water samples from 28 hotsprings and mineral springs in Nagano Prefecture, central Japan, were examined for their stable isotope ratios of hydrogen, oxygen, carbon, and sulfur. Spring waters of Kashio are highly saline and enriched in heavy isotopes of oxygen and hydrogen (δ(18)O=-2.5～-4.6‰, δD=-54～-57‰). Linear relationships among δD, δ(18)O, and Cl(-) suggest that spring waters are the mixtures of a deep brine and local surface water. Extrapolation of the linear relationships indicates that the deep brine is both isotopically and chemically very similar to the deep brine previously suggested for the springs of Arima, Takarazuka, and Ishibotoke of which δD, δ(18)O, and Cl(-) are estimated as -33‰, +8.0‰, and 44g/l, respectively. A common origin may be warranted among these postulated brines, while their provenance is yet to be worked out. The hot springs in Matsushiro are a Na-Ca-Cl type of high carbonate content. Their hydrogen and oxygen isotope ratios (δD=-71～-46‰, δ(18)O=-9.1～-2.0‰) are higher than the local surface water. On the basis of the relationships among δD, δ(18)O, and Cl(-), they are considered to be the mixtures of fossil sea water and certain water of meteoric origin of which Cl(-) is about 4g/l and δ(18)O is higher by about 3‰ than the local surface water. The latter may be meteoric water circulating in the marine sedimentary formations (Green Tuff formations) with soluble sea salts. Isotopic exchange with carbonate minerals in the formations explains its (18)O enrichment. Spring waters from Yashio and Isobe (Gunma Pref.) as well as Yunosawa and Yatate (Akita Pref.) were previously interpreted to be mixtures of fossil sea water and local surface water of low Cl(-) content. Re-examination of their data revealed that the meteoric waters responsible for these springs contain about 3g/l Cl(-), similar to the value obtained for Matsushiro. However, unlike Matsushiro, the meteoric waters in these areas are found to be isotopically similar to the local surface waters. Waters from other hot springs studied here are of simply meteoric origin, thus belonging to the GreenTuff type water previously defined

Realization of a collective decoding of codeword states

This was also extended from the previous article quant-ph/9705043, especially in a realization of the decoding process.Comment: 6 pages, RevTeX, 4 figures(EPS

Valence and Na content dependences of superconductivity in NaxCoO2.yH2O

Various samples of sodium cobalt oxyhydrate with relatively large amounts of Na$^{+}$ ions were synthesized by a modified soft-chemical process in which a NaOH aqueous solution was added in the final step of the procedure. From these samples, a superconducting phase diagram was determined for a section of a cobalt valence of $\sim$+3.48, which was compared with a previously obtained one of $\sim$+3.40. The superconductivity was significantly affected by the isovalent exchanger of Na$^{+}$ and H$_{3}$O$^{+}$, rather than by variation of Co valence, suggesting the presence of multiple kinds of Fermi surface. Furthermore, the high-field magnetic susceptibility measurements for one sample up to 30 T indicated an upper critical field much higher than the Pauli limit supporting the validity of the spin-triplet pairing mechanism.Comment: 4 figures and 1 tabl

Monopole Dominance for Nonperturbative QCD

Monopole dominance for the nonperturbative features in QCD is studied both in the continuum and the lattice gauge theories. First, we study the dynamical chiral-symmetry breaking (D$\chi$SB) in the dual Higgs theory using the effective potential formalism. We find that the main driving force for D$\chi$SB is brought from the confinement part in the nonperturbative gluon propagator rather than the short-range part, which means monopole dominance for D$\chi$SB. Second, the correlation between instantons and QCD-monopoles is studied. In the Polyakov-like gauge, where $A_4(x)$ is diagonalized, the QCD-monopole trajectory penetrates the center of each instanton, and becomes complicated in the multi-instanton system. Finally, using the SU(2) lattice gauge theory with $16^4$ and $16^3 \times 4$, the instanton number is measured in the singular (monopole-dominating) and regular (photon-dominating) sectors, respectively. Instantons and anti-instantons only exist in the monopole sector both in the maximally abelian gauge and in the Polyakov gauge, which means monopole dominance for the topological charge.Comment: Talk presented by H. Suganuma at the Joint Japan-Australia Workshop on "Quarks, Hadrons and Nuclei'', 15 - 24 Nov. 1995, in Adelaide, Australia, 10 pages, Plain Latex, ( 6 figures - available on request from [email protected]