Beta-decay half-lives calculated on the gross theory

Beta-decay half-lives have been calculated by the use of the gross theory which was formulated by Takahashi, Yamada, and Koyama. Both allowed and first-forbidden transitions have been taken into account, and consideration also has been given to the possibility that all the transitions to the levels near the ground states may be highly forbidden. The Q-values used in the calculation have been taken from the mass formula of Myers and Swiatecki. The calculated half-lives are shown in the PLOTS together with the experimental data and the Q-values. The PLOTS cover all the isotopes between the proton-drip and neutron-drip lines with Z = 3 to Z = 100.     

Irrigation

This paper provides an overview of the main features of irrigation in Japan, and the issues it raises, rather than an exhaustive survey of the subject. The authors’ remarks concentrate on irrigation for rice cultivation, since irrigation for non‐paddy crops is not widely developed and claims a very minor share of the country's water resources. The main components of the water requirements of rice irrigation are identified, and then the composition and functions of farmers’ irrigation associations, or more correctly ‘land improvement districts’, are described.     

Compact optical circulator for near-infrared region

A compact Faraday-rotation 4-port circulator was developed for the near-infrared region. This circulator consists of an yttrium-iron-garnet Faraday rotator, biased by two permanent magnets, and two Glan-Taylor prisms. Insertion losses of 2.7?3.2 dB and isolation ratios of 13?28 dB among non-reciprocal ports were obtained at 1.15?m wavelength.     

Effect of hydroxypropyl-beta-cyclodextrin on the degradation of pentachlorophenol by potassium monopersulfate catalyzed with iron(III)-porphyrin complex

A novel biomimetic catalytic system containing a supramolecular complex between iron(III)-tetrakis(p-sulfonatophenyl)porphyrin [Fe(III)-TPPS] and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was examined for the potassium monopersulfate catalyzed oxidation of pentachlorophenol (PCP). In the absence of HP-beta-CD, the percentage of PCP disappearance and the numbers of chlorine atoms released from PCP increased to 50% and 1.5 for a 1-day reaction period, respectively. However, in the presence of HP-beta-CD, the PCP completely disappeared and the number of chlorine atoms from PCP was increased to 3.1. o-Tetrachloroquinone, 2- and 4-hydroxyl-nonachlorodiphenyl ethers, and octachlorodibenzo-p-dioxin were detected among the oxidation products. In the absence of HP-beta-CD, the percentage of PCP conversion to oxidation products increased and then reached plateau. In the presence of HP-beta-CD, the amount of oxidation products produced initially increased for the first 10 min and thereafter decreased gradually. These results suggest that the addition of HP-beta-CD results in the further degradation of oxidation products. In addition, the mineralization of PCP to CO2 was investigated using 14C6-labeled PCP. After a 1-day reaction period, 24% of the 14C6-labeled PCP was converted to 14CO2 in the presence of HP-beta-CD, although significant 14CO2 generation was not observed in its absence. The effect of HP-beta-CD on the facilitation of PCP degradation can be attributed to the fact that the self-oxidation of Fe(III)-TPPS is prevented by the formation of a stable supramolecular complex between HP-beta-CD and Fe(III)-TPPS.     

A nationwide survey of NDMA in raw and drinking water in Japan

A nationwide survey of N-nitrosodimethylamine (NDMA) in both raw and finished water samples from drinking water treatment plants (DWTPs) in Japan was conducted. NDMA was analyzed by solid-phase extraction (SPE) followed by ultra performance liquid chromatography (UPLC) coupled with tandem mass spectrometry (MS/MS). NDMA was detected in 15 of 31 raw water samples collected in the summer at concentrations up to 2.6 ng/L, and in 9 of 28 raw water samples collected in winter at concentrations up to 4.3 ng/L. The NDMA concentrations were higher in raw water samples collected from treatment plants with catchment areas that have high population densities. The NDMA concentrations were higher in river water samples collected from the east and west of Japan than in those collected from other areas. NDMA was detected in 10 of 31 finished samples collected in summer at reduced concentrations of up to 2.2 ng/L, while 5 of 28 finished samples collected in winter showed NDMA concentrations up to 10 ng/L. The highest NDMA levels were detected in finished water samples collected from the Yodo River basin DWTP, which uses ozonation. Furthermore, evaluation of the process water produced at six advanced water treatment plants was conducted. Influent from the Yodo River indicated that the NDMA concentration increased during ozonation to as high as 20 ng/L, and then decreased with subsequent biological activated carbon treatment. To our knowledge, this is the first nationwide evaluation of NDMA concentrations in water conducted in Japan to date.     

Isotopic evidence in tree rings for historical changes in atmospheric sulfur sources

Little is understood about the usefulness of sulfur isotopic ratios (sigma 34S) in tree rings because the sulfur content in rings is generally insufficient for analysis using conventional methods. We present sigma 34S values of the water-soluble and the organically bound sulfur fractions in rings of coniferous trees grown in Japan, analyzed using a large-volume oxygen bomb. Comparing the sigma 34S values of the organically bound fraction in tree rings with past atmospheric sulfur concentrations and with those of their sources, we find clear evidence that the sigma 34S values of the organically bound fraction in the rings are dependent upon the values of the atmospheric sulfur sources. The evidence suggests that the sigma 34S values in tree rings are a useful chronological proxy for evaluating possible causes of past atmospheric sulfur pollution.