Speciation of iodine in solid environmental samples by iodine K-edge XANES: application to soils and ferromanganese oxides

A method was developed for speciation of iodine in solid materials using X-ray absorption near-edge structure (XANES). This method was used to identify the iodine species (mainly inorganic iodine) in environmental samples. It was shown that the XANES spectra of iodide and iodate sorbed within solid materials can be simulated by the linear combination of the spectra of iodide and iodate ions in water. The distribution coefficient (Kd) between soil and water was obtained independently for iodide and iodate, based on iodine speciation both in the solid phase, by XANES, and in the aqueous phase, by HPLC-ICP-MS. It was found that the Kd of iodate is larger than that of iodide by a factor of more than six, showing the more soluble nature of iodide. It was suggested that iodate can form in soil even when iodide is injected into the soil-water system under conditions within the iodide-stable field of the Eh-pH diagram of iodine. This is caused by the much higher affinity of iodate for solid surfaces than iodide. In soil samples under various water saturation conditions, or various Eh conditions, the iodide fraction in water increases with decreasing Eh, which results in an increase in the dissolved total iodine fraction in soil water. The speciation method using XANES was also applied to iodine in a natural soil sample and marine ferromanganese oxides. It is suggested that iodine K-edge XANES is a promising tool for determining the iodide/iodate ratio in natural solid samples, which contributes to better understanding of the behavior of iodine at the Earth's surface.     

A pipeline-based approach for maximal-sized matching scheduling ininput-buffered switches

This letter proposes an innovative pipeline-based maximal-sized matching scheduling approach, called PMM, for input-buffered switches. It dramatically relaxes the timing constraint for arbitration with a maximal matching scheme. In the PMM approach, arbitration operates in a pipelined manner. Each subscheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides the matching result. The subscheduler can adopt a pre-existing efficient round-robin-based maximal matching algorithm. We show that PMM provides 100% throughput under uniform traffic since it preserves a desynchronization effect of the round-robin pointers as in the preexisting algorithm. In addition, PMM maintains fairness for best-effort traffic due to the round-robin-based arbitration     

Study of temperature factors in cubic crystals by high-voltage electron diffraction

The critical voltages for systematic reflections and splits of Kikuchi lines were measured using a high-voltage electron microscope to investigate the atomic temperature factors in cubic crystals. The split of the Kikuchi line at the intersection with the forbidden 222 Kikuchi line as well as the critical voltage of the 333 reflection for Si and Ge decreased steeply with temperature. The temperature dependence showed that the anharmonic contribution to the atomic-temperature factor for Si and Ge is extremely weak in the temperature range 300 ～ 1078 K. On the contrary, the B factors obtained from the measured critical voltages for Al, Cu, and Fe varied nonlinearly with temperature, suggesting the importance of the anharmonic effect in the vibration of atoms. The observed temperature dependence of the critical voltages for the metals were compared with calculations based on harmonic, quasi-harmonic, and anharmonic approximations. The quasi-harmonic approximation that takes into account the thermal expansion modification reproduces well the observed values for Fe but not those for Al and Cu. The effect of intrinsic anharmonic vibration should be considered for reproducing the results for Al and Cu. Fitting the measured critical voltages with the calculated ones, we estimated the values for coefficients of the isolated atom potentials. The results are in good agreement with those obtained by neutron and X-ray diffraction.     

On the dynamics of frontier economies: Endogenous growth or the self-organization of a dissipative system?

This paper aims to demonstrate that the basic framework of the „new geographical economics” is well suited to explain various phenomena associated with the dynamics of frontier economies, such as the „massive mobilization of resources” and the so-called „flying geese pattern” of Asia‘s development. The discussion is based on the monopolistic competition model of spatial economy which we are currently developing with Paul Krugman.     

Very small single-mode ten-fiber connector

A small plastic molded single-mode ten-fiber connector has been developed for high-count optical subscriber cables. The connector ferrule alignment mechanism is designed with a sufficient factor of safety to allow rough handling during connection. The ferrules are precisely aligned by alignment pins and guide sleeve. The fabricated connector, which has a cross section of just 4 mm × 6 mm, exhibited an average loss of 0.4 dB and reconnection time of less than 0.5 min. Connection loss does not change after over 1000 reconnections     

A longitudinal study of three-year-old children with delayed development of language

From January 1982 to December 1986, 113 three-year-old children (100 boys and 13 girls) visited the department of pediatrics, Asahikawa Medical College, because of delayed development of language (their expressive language age less than two-year-old). Of these children, 102 children (90%) have visited until they graduated from junior high school for the evaluation of intelligence quotient (IQ), diagnosis, the type of attended school and complications. The mean follow-up period was 10.8 years. The 113 children ware classified as 32 cases of developmental language disorder (DLD), 38 of autistic disorder (Au), 39 of mental retardation (MR), and 4 of deafness based on the results of clinical examination (DSM-III-R), ABR and WPPSI/WISC-R. The purpose of this study is to compare the assessment of language development at the age 3 with the prognosis for intelligence, academic achievement and behavioral adjustment. At the age of three, we divided them into three groups using the Enjoji shiki hattatsu kensa-hyo. Group A including 31 children (29 boys and 2 girls) means delayed development in verbal expression only. Group B including 23 children (17 boys and 6 girls) means delayed development in verbal expression and comprehension. Group C including 59 children (54 boys and 5 girls) means delayed development not only in verbal expression and comprehension but also in communication skills. RESULTS: ABR: Four (2 boys and 2 girls) of 113 children did not show any significant waves on ABR at aged 3, and were also diagnosed as deafness by another audiometry. Comparison between the assessment of verbal expression at aged 3 and full scale IQ (FSIQ): FSIQs in 77% of group A were more than 70, while FSIQs in 79% of groups B and C were 70 or below. The assessment of verbal comprehension at aged 3 was significantly related with FSIQ (x2 = 23.88, p < 0.01). Classification of disorders and type of schools according to the assessment at aged 3: [Group A] Thirty one children were classified as 25 cases of DLD and 6 of MR. Before a graduation from junior high school, 20 children attended regular classes and 8 attended special classes for MR. [Group B] Twenty three children were classified as 4 cases of DLD, 10 of MR, 5 of Au and 4 of deafness. Before a graduation from junior high school, 4 children attended regular classes, 8 attended special classes for MR, 6 attended special schools for MR and 4 attended schools for deafness. [Group C] Fifty nine children were classified as 3 cases of DLD, 23 of MR and 33 of Au. Before graduating from junior high school, 10 children attended regular classes, 18 attended special classes for MR, 19 attended special schools for MR and 2 entered educational facilities. CONCLUSION: 1. Poor mental outcome could be predicted by delayed development of both expressive and comprehensive language, particularly associated with dysfunction of communication skills at the age of three. 2. ABR is a useful method for detecting of hearing loss in non-cooperative young children with delayed development of language.     

Numerical simulation of a pulsed laser pumped distributed-feedback waveguided dye laser by coupled-wave theory

A dynamic model of pulsed laser pumped distributed-feedback (DFB) waveguided dye laser based on a coupled-wave theory is described. Due to the periodical distribution of the intensities of pump source and stimulated emission along the waveguide, the rate equations of the population densities are turned into the equations of the Fourier coefficients. Coupled-wave equations of optical fields are used to simulate the laser oscillation. Besides the temporal evolution of the output intensity, the spectra can also be obtained by the Fourier transform of the optical fields. Two different configurations of the waveguided dye laser, prefabricated DFB (mainly index coupling), first- and second-order holographic DFB (dynamic gain-coupling), are considered in the model. The simulation shows that: 1) the temporal waveforms of the holographic DFB consist of sharp spikes; 2) the broadened spectral widths resulted from the possible nonuniformities in propagation constant or grating period are less than 50 pm except for the second-order holographic DFB; and 3) strong parasitic oscillations can be observed in the second-order holographic DFB with terminal reflection. These results and the comparisons of some of them to the experiments are reported.