Galaxy redshift abundance periodicity from Fourier analysis of number counts N(z) using SDSS and 2dF GRS galaxy surveys

A Fourier analysis on galaxy number counts from redshift data of both the Sloan Digital Sky Survey and the 2dF Galaxy Redshift Survey indicates that galaxies have preferred periodic redshift spacings of Δz= 0.0102, 0.0246, and 0.0448 in the SDSS and strong agreement with the results from the 2dF GRS. The redshift spacings are confirmed by the mass density fluctuations, the power spectrum P(z) and N _pairs calculations. Application of the Hubble law results in galaxies preferentially located on co-moving concentric shells with periodic spacings. The combined results from both surveys indicate regular co-moving radial distance spacings of 31.7±1.8 h^?1?Mpc, 73.4±5.8 h^?1?Mpc and 127±21 h^?1? Mpc. The results are consistent with oscillations in the expansion rate of the universe over past epochs.     

Kalman filtering in groundwater flow modelling: problems and prospects

The popularity of applying filtering theory in the environmental and hydrological sciences passed its first climax in the 1970s. Like so many other new mathematical methods it was simply the fashion at the time. The study of groundwater systems was not immune to this fashion, but neither was it by any means a prominent area of application. The spatial-temporal characteristics of groundwater flow are customarily described by analytical or, more frequently, numerical, physics-based models. Consequently, the state-space representations associated with filtering must be of a high order, with an immediately apparent computational over-burden. And therein lies part of the reason for the but modest interest there has been in applying Kalman filtering to groundwater systems, as reviewed critically in this paper. Filtering theory may be used to address a variety of problems, such as: state estimation and reconstruction, parameter estimation (including the study of uncertainty and its propagation), combined state-parameter estimation, input estimation, estimation of the variance-covariance properties of stochastic disturbances, the design of observation networks, and the analysis of parameter identifiability. A large proportion of previous studies has dealt with the problem of parameter estimation in one form or another. This may well not remain the focus of attention in the future. Instead, filtering theory may find wider application in the context of data assimilation, that is, in reconstructing fields of flow and the migration of sub-surface contaminant plumes from relatively sparse observations. Received: October 27, 1997     

Urban climate simulation by incorporating satellite-derived vegetation cover distribution into a mesoscale meteorological model

Summary We simulated urban climate with surface boundary conditions based on satellite remote sensing (RS) data. Most previous mesoscale meteorological modeling studies use land-use data instead as the surface boundary conditions. However, small patches of vegetation-cover, such as roadside trees and garden trees, are excluded from the land-use data. Therefore, we made a fractional vegetation cover (FVC) dataset with these small patches of vegetation-cover from RS data, and then simulated the urban heat island in Tokyo with FVC data as new surface boundary conditions. In addition, we compared the above simulation results with results from a simulation that used only land-use data. The comparison shows that the air temperature with the new boundary condition is up to 1.5°C lower than that with the old boundary condition. Furthermore, the new boundary condition led to predicted air temperatures closer to the measured temperatures than those with the old boundary condition. Therefore, it is important for urban climate simulations to include small vegetation cover.     

A study on the chemical forms of radionuclides in seawater—II chloride and sulfate complexes of60Co

The apparent stability constants for chloride and sulfate ions with Co (II) at ionic strength of 0.67 were determined by the cation exchange method. The value of the stability constant ₁ for chloride ion with Co (II) ion was 0.79±0.055. The stability constants ₁, ₂ and ₃ for sulfate ion with Co (II) ion were 12.0±0.27, 91.5±11.4 and l,110±250, respectively. The chemical species of Co (II) in seawater was estimated at the pH of 8.0 to be present as Co²⁺ (63%), CoCl⁺ (27%) and CoSO₄ ⁰ (8.6%) using the known value of dissociation constant of Co (II), and under the assumption that only major inorganic anions are responsible for the chemical equilibrium of Co (II).     

Iron K-emission line from Cygnus X-2

The iron K-emission line of Cyg X-2 was detected from the TENMA observation. The centre energy, the equivalent width and the intrinsic line width are 6.7 keV, 30 eV, and less than 0.6 keV, respectively. These properties indicate that the observed line is mostly due to helium-like iron and the electron scattering depth of the line emitting region is smaller than three.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.     

Movement of radiocaesium fallout released by the 2011 Fukushima nuclear accident

The moment magnitude (M _w) 9.0 Tohoku-Oki Earthquake occurred on March 11, 2011, generating an unusually large tsunami. The seismic shocks and tsunami inundation severely damaged the Fukushima Daiichi Nuclear Power Plant. Radionuclide emission due to reactor breakdown contaminated wide areas of Fukushima and its surroundings. Heavy rainfall causes runoff across surface soil, and fine soil particles are susceptible to uptake by the flowing water. The high radioactivity of grains suspended in floodwater indicates that radioactive fallout was streamed into rivers in particulate form and transported downstream under high-flow conditions. Here, we investigated the diachronic mode of ¹³⁴Cs and ¹³⁷Cs in central Fukushima, through which the contaminated air mass drifted and caused wet deposition of radionuclides. Stratigraphic measurements of radioactivity in sediment cores is the method employed in this study to determine the basin-wide movement of ¹³⁴Cs and ¹³⁷Cs, to evaluate the significance of the erosion–transportation–accumulation processes on natural decontamination in terrain characterized by steep slopes and high precipitation. Stratigraphic results illustrate the process of fluvial sediment discharge, and the massive deposition of radiocaesium suggests basin-wide movement of fallout during concentrated rainfall. Grain suspension in torrential currents is an important pathway for transportation of radionuclides from land to sea, and the appearance of hotspots on floodplains and the offshore sea floor is the consequence of erosion and transportation under seasonal heavy precipitation. Radioactive horizons occur in offshore sediment columns and thus radiocaesium discharged from the estuary will persist forever under the sea floor if no artificial disturbance occurs.     

Particle associated polycyclic aromatic hydrocarbons in the atmospheric environment of urban and suburban residential area

Ten polycyclic aromatic hydrocarbons associated with suspended particulate matter in the ambient air were collected at two sampling sites: urban and suburban residential areas of Yokohama, Japan from 1999 to 2005. The concentrations of target compounds were determined using gas chromatography-mass spectrometry. The total concentrations were higher in urban residential area than suburban residential area. They ranged from 0.31 to 6.16 ng/m3 withameanof2.07ng/m3 and 0.33 to2.87ng/m3 with a mean of 1.02 ng/m3 in the urban and suburban residential areas, respectively. The predominant compounds determined both in the urban and suburban residential areas were benzo[b]fluoranthene, benzo[ghi]perylene, indeno[1,2,3-cd]pyrene and benzo[e]pyrene. The concentrations of 5- and 6-ring polycyclic aromatic hydrocarbons were higher in the urban than the suburban residential area, accounting for 77.3 % and 72.1 % of total polycyclic aromatic hydrocarbons, respectively. Source identification was performed by principal component analysis. Two principal components were identified for each study area and these accounted for 95.9 % and 83.3 % of total variance, respectively. The results revealed that stationary source and vehicle emissions were the major pollution sources in the studied areas. The impact of emission regulations for automobiles in large Japanese cities, which were enacted during 2002 and 2003, was also studied. Based on the average total concentration, emission reduction was 47.8 % and 18.6 % in urban residential and suburban residential areas, respectively.     

Laplace method to investigate subsurface geologic structures and its application

The ages of layered strata show a particular spatial distribution, and the bedding plane is isopotential surface of a scalar T(x, y, z) correlative to the age of a given stratigraphic horizon. The scalar T is obtained as the solution of boundary value problem of Laplace equation in power series, and the solution describes the three-dimensional geologic structures within an analytical space bounded by faults or unconformities on which the value of T jumps. The solution is termed the horizon function and consists of the datum succession and the structural part. The datum succession defines the relationship between the relative age (time-scale; T) and the thickness of strata (spatial scale; z) for undeformed horizontal strata. Geologic structures are described by the structural part of the solution composed by Fourier series, and the coefficients included there are determined by the least-square method using the dip and strike defined by particular combinations of the derivatives of T or the horizon data obtained in the area. The undersampled nature of geologic data is overcome by the selection of solution type, Eigenvalues, and boundary condition. Geological map and cross-sections are composed quantitatively and automatically by combining the spatial distribution of investigated T with the digital map defining the landform of the area. Test results were examined from this point of view. Improvement of the structural part to have the result fit completely the measured data is possible by introduction of the multiplying polynomials, although this concerns mathematical nature of the potential T.     

A Paleogene magmatic overprint on Cretaceous seamounts of the western Pacific

The West Pacific Seamount Province (WPSP) represents a series of short-lived Cretaceous hotspot tracks. However, no intraplate volcanoes in advance of petit-spot volcanism erupted near a trench have been identified after the formation of the WPSP on the western Pacific Plate. This study reports new ages for Paleogene volcanic edifices within the northern WPSP, specifically the Ogasawara Plateau and related ridges, and Minamitorishima Island. These Paleogene ages are the first reported for basaltic rocks on western Pacific seamounts, in an area that has previously only yielded Cretaceous ages. The newly found Paleogene volcanisms overprint the Early–middle Cretaceous volcanic edifices, because the seamount or paleo-island material-covered reefal limestone caps on these edifices are uniformly older than the Paleogene volcanism identified in this study. This study outlines several possible causative factors for the Paleogene volcanism overprinting onto existing Cretaceous seamounts, including volcanism related to lithospheric stress, or a younger hotspot track within the northern part of the WPSP that records magmatism from ~60 Ma.     

Multi-approach characterization of shallow-water carbonates off Minamitorishima and their depositional settings/history

Sedimentological, geochemical, and chronological analyses were carried out on 18 carbonate rock samples collected at depths of 938, 1085, and 3354 m on the western slope of Minamitorishima (Marcus Island), which is located near the western margin of the Pacific Plate. Four groups of carbonate rocks were distinguished: a mollusk-rich limestone, a coral-rich dolomite, a foraminiferal-nannofossil packstone, and a phosphatized mudstone/wackestone. The mollusk-rich limestone is characterized by the dominance of bivalves (including rudists) and gastropod shells. Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) and Mesorbitolina ex gr. texana (a large benthic foraminifer) indicate that the shallow-water carbonates were deposited during the late Aptian–early Albian (ca. 123–111 Ma). The coral-rich dolomite is characterized by abundant scleractinian corals and nongeniculate coralline algae associated with encrusting acervulinid foraminifers. The biotic composition is similar to that of the Oligocene–Pleistocene carbonates reported from other seamounts in the northwestern Pacific. Geochemical data show that the coral-rich carbonates were dolomitized at 9.5–6.8 Ma (Tortonian–Messinian) and that normal seawater was the most likely parent fluid. The foraminiferal-nannofossil packstone is a semi-consolidated foraminiferal-nannofossil ooze and was deposited during the Pleistocene (0.99–0.45 Ma). The phosphatized mudstone/wackestone is marked by the absence of macrofossils and the presence of traces of planktic foraminifers. Although its depositional age is not constrained, the Sr isotope ratios indicate that the phosphatization occurred at 33.2–28.9 Ma. After the deposition of the Cretaceous shallow-water carbonates, including the mollusk-rich limestone, Minamitorishima was drowned and its top was covered with a pelagic cap, represented by the mudstone/wackestone. The late Eocene–early Oligocene volcanism (40.2–33.2 Ma) caused episodic uplift and returned the top of Minamitorishima to a shallow-water environment. After the early Oligocene phosphatization of the pelagic cap, coral reefs flourished on the top of this island. The reef limestone was dolomitized during the Tortonian–Messinian.