61 research outputs found

    On-Site Bridge Inspection by 950 keV/3.95 MeV Portable X-Band Linac X-Ray Sources

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    Many bridges around the world face aging problems and degradation of structural strength. Visual and hammering sound inspections are under way, but the status of inner reinforced iron rods and prestressed concrete (PC) wires has not yet been confirmed. Establishing a diagnosis method for bridges based on X-ray visualization is required to evaluate the health of bridges accurately and to help with the rationalization of bridge maintenance. We developed 950 keV/3.95 MeV X-band electron linac-based X-ray sources for on-site bridge inspection and visualized the inner structure of a lower floor slab. The information regarding wire conditions by X-ray results was used for the structural analysis of a bridge to evaluate its residual strength and sustainability. For more precise inspection of wire conditions, we applied three-dimensional image reconstruction methods for bridge mock-up samples. Partial-angle computed tomography (CT) and tomosynthesis provided cross-sectional images of the samples at 1 mm resolutions. Image processing techniques such as the curvelet transform were applied to evaluate diameter of PC wires by suppressing noise. Technical guidelines of bridge maintenance using the 950 keV/3.95 MeV X-ray sources are proposed. We plan to offer our technique and guidelines for safer and more reliable maintenance of bridges around the world

    Laser-induced-fluorescence measurement of thermal conductivity in warm dense matter generated by pulsed-power discharge

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    Thermal conductivity in warm dense matter is one of the interests for thermonuclear fusion scenarios. Alternative inertial confinement fusion, which is a fast ignition with applied magnetic field [1], has been considered to improve the coupling efficiency. The target behavior of the fast ignition with applied magnetic field depends on the anisotropic thermal conductivity. The magnetic confinement fusion (MCF) [2] Up to now, the heat load on the divertor in previous MCF systems has been unreached parameter. Thus, to predict properties of the divertor under these heat loads, several experiments have been performed using several methods[3-6]. To predict the performance of the tungsten divertor in MCF, we should analyze not only metallurgical properties but also thermophysical properties of ablated tungsten..

    Laser-induced-fluorescence measurement of thermal conductivity in warm dense matter generated by pulsed-power discharge

    Get PDF
    Thermal conductivity in warm dense matter is one of the interests for thermonuclear fusion scenarios. Alternative inertial confinement fusion, which is a fast ignition with applied magnetic field [1], has been considered to improve the coupling efficiency. The target behavior of the fast ignition with applied magnetic field depends on the anisotropic thermal conductivity. The magnetic confinement fusion (MCF) [2] Up to now, the heat load on the divertor in previous MCF systems has been unreached parameter. Thus, to predict properties of the divertor under these heat loads, several experiments have been performed using several methods[3-6]. To predict the performance of the tungsten divertor in MCF, we should analyze not only metallurgical properties but also thermophysical properties of ablated tungsten..

    Highway PC Bridge Inspection by 3.95 MeV X-Ray/Neutron Source

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    We have developed portable 950 keV/3.95 MeV X-ray/neutron sources and applied them to inspection of PC concrete thicker than 200 mm within reasonable measuring time of seconds - minutes. T-girder-, Box- and slab- bridges are considered. Now we are to start X-ray transmission inspection for highway PC bridge (box) by using 3.95 MeV X-ray sources in Japan in 2020. By obtaining X-ray transmission images of no-grout-filling in PC sheath and thinning of PC wires, we plan to carry out numerical structural analysis to evaluate the degradation of strength. Finally, we are going to propose a technical guideline of nondestructive evaluation (NDE) of PC bridges by taking account of both X-ray inspection and structural analysis. Further, we are trying to detect rainwater detection in PC sheath, and asphalt and floor slab by the 3.95 MeV neutron source. This is expected to be an early degradation inspection. We have done preliminary experiments on X-ray transmission imaging of PC wires and on-grout-filling in the same height PCs in 450–750 mm thick concretes. Moreover, neutron back scattering detection of water in PC sheath is also explained

    Quantitative analysis of major elements in igneous rocks with X-ray fluorescence spectrometer “ZSX primus II” using a 1:10 dilution glass bead

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    Detailed procedures of sample processing including preparation of a 1: 10 dilution glass bead and evaluations of calibration lines of the X-ray fluorescence spectrometer for major element compositions of igneous rock samples are presented. We used 11 igneous rock standard samples of the Geological Survey of Japan and the synthetic material for the calibration. A powdered rock sample ignited at 900 ° C for four hours and lithium tetraborate as an alkali flux ignited at 700 ° C for four hours are weighed 0.4000 ± 0.0001 g and 4.0000 ± 0.0001 g, respectively. The mixture of rock powder sample and lithium tetraborate is put into a platinum crucible and fused to a glass bead. The calibration lines for basalts and andesites named "Major12" analyze 10 major elements such as Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K and P in 10 minutes. The result of repeated analyses of six standard materials shows that the relative standard deviations are less than 3% and relative errors are less than 1.2%. Therefore, the calibration lines "Major12" are sufficient to be applied to routine measurement of igneous rocks. For analysis of ultramafic rocks, another set of calibration lines "majorOl\u27\u27 was made based on standard samples including synthesized materials of SiO, and MgO reagents, and the calibration lines cover wider Si, Mg, Ni and Cr ranges than "Major12". The calibration lines "majorOl\u27\u27 successfully reproduced concentrations of nine major element compositions (Si, Ti, Al, Fe, Mn, Mg, Ca, Ni, Cr) of the standard samples of ultramafic rocks

    Basalt derived from highly refractory mantle sources during early Izu-Bonin-Mariana arc development

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    The magmatic character of early subduction zone and arc development is unlike mature systems. Low-Ti-K tholeiitic basalts and boninites dominate the early Izu-Bonin-Mariana (IBM) system. Basalts recovered from the Amami Sankaku Basin (ASB), underlying and located west of the IBM’s oldest remnant arc, erupted at ~49 Ma. This was 3 million years after subduction inception (51-52 Ma) represented by forearc basalt (FAB), at the tipping point between FAB-boninite and typical arc magmatism. We show ASB basalts are low-Ti-K, aluminous spinel-bearing tholeiites, distinct compared to mid-ocean ridge (MOR), backarc basin, island arc or ocean island basalts. Their upper mantle source was hot, reduced, refractory peridotite, indicating prior melt extraction. ASB basalts transferred rapidly from pressures (~0.7-2 GPa) at the plagioclase-spinel peridotite facies boundary to the surface. Vestiges of a polybaric-polythermal mineralogy are preserved in this basalt, and were not obliterated during persistent recharge-mix-tap-fractionate regimes typical of MOR or mature arcs

    Origin of depleted basalts during subduction initiation and early development of the Izu-Bonin-Mariana island arc: Evidence from IODP expedition 351 site U1438, Amami-Sankaku basin

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    The Izu-Bonin-Mariana (IBM) island arc formed following initiation of subduction of the Pacific plate beneath the Philippine Sea plate at about 52 Ma. Site U1438 of IODP Expedition 351 was drilled to sample the oceanic basement on which the IBM arc was constructed, to better understand magmatism prior to and during the subduction initiation event. Site U1438 igneous basement Unit 1 (150 m) was drilled beneath 1460 m of primarily volcaniclastic sediments and sedimentary rock. Basement basalts are microcrystalline to fine-grained flows and form several distinct subunits (1a-1f), all relatively mafic (MgO = 6.5–13.8%; Mg# = 52–83), with Cr = 71–506 ppm and Ni = 62–342 ppm. All subunits are depleted in non-fluid mobile incompatible trace elements. Ratios such as Sm/Nd (0.35–0.44), Lu/Hf (0.19–0.37), and Zr/Nb (55–106) reach the highest values found in MORB, while La/Yb (0.31–0.92), La/Sm (0.43–0.91) and Nb/La (0.39–0.59) reach the lowest values. Abundances of fluid-mobile incompatible elements, K, Rb, Cs and U, vary with rock physical properties, indicating control by post-eruptive seawater alteration, but lowest abundances are typical of fresh, highly depleted MORBs. Mantle sources for the different subunits define a trend of progressive incompatible element depletion. Inferred pressures of magma segregation are 0.6–2.1 GPa with temperatures of 1280–1470 °C. New 40Ar/39Ar dates for Site U1438 basalts averaging 48.7 Ma (Ishizuka et al., 2018) are younger that the inferred age of IBM subduction initiation based on the oldest ages (52 Ma) of IBM forearc basalts (FAB) from the eastern margin of the Philippine Sea plate. FAB are hypothesized to be the first magma type erupted as the Pacific plate subsided, followed by boninites, and ultimately typical arc magmas over a period of about 10 Ma. Site U1438 basalts and IBM FABs are similar, but Site U1438 basalts have lower V contents, higher Ti/V and little geochemical evidence for involvement of slab-derived fluids. We hypothesize that the asthenospheric upwelling and extension expected during subduction initiation occurred over a broad expanse of the upper plate, even as hydrous fluids were introduced near the plate edge to produce FABs and boninites. Site U1438 basalts formed by decompression melting during the first 3 Ma of subduction initiation, and were stranded behind the early IBM arc as mantle conditions shifted to flux melting beneath a well-defined volcanic front.This research was supported by grants from the Consortium for Ocean Leadership to R. Hickey-Vargas and G. Yogodzinski, and collaborative National Science Foundation grants OCE1537861 to R. Hickey-Vargas and OCE1537135 to G. Yogodzinski and M. Bizimis. O. Ishizuka acknowledges Grant-in-Aid (B) (No. 25287133) for sample preparation, and I.P. Savov acknowledges support from the UK-IODP and NERC NE/M007782/1. The authors thank the International Ocean Discovery Program for this opportunity and gratefully acknowledge the input and efforts of all Expedition 351 shipboard scientists, IODP staff and crew of the JOIDES Resolution. R. Hickey-Vargas thanks Dr. Tatiana Trejos and Dr. Jose Almirall of FIU’s Trace Evidence Analysis Facility for use of the ICP-mass spectrometers and for sharing their analytical expertise

    Age of Izu-Bonin-Mariana arc basement

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    Documenting the early tectonic and magmatic evolution of the Izu–Bonin–Mariana (IBM) arc system in the Western Pacific is critical for understanding the process and cause of subduction initiation along the current convergent margin between the Pacific and Philippine Sea plates. Forearc igneous sections provide firm evidence for seafloor spreading at the time of subduction initiation (52 Ma) and production of “forearc basalt”. Ocean floor drilling (International Ocean Discovery Program Expedition 351) recovered basement-forming, low-Ti tholeiitic basalt crust formed shortly after subduction initiation but distal from the convergent margin (nominally reararc) of the future IBM arc (Amami Sankaku Basin: ASB). Radiometric dating of this basement gives an age range (49.3–46.8 Ma with a weighted average of 48.7 Ma) that overlaps that of basalt in the present-day IBM forearc, but up to 3.3 m.y. younger than the onset of forearc basalt activity. Similarity in age range and geochemical character between the reararc and forearc basalts implies that the ocean crust newly formed by seafloor spreading during subduction initiation extends from fore- to reararc of the present-day IBM arc. Given the age difference between the oldest forearc basalt and the ASB crust, asymmetric spreading caused by ridge migration might have taken place. This scenario for the formation of the ASB implies that the Mesozoic remnant arc terrane of the Daito Ridges comprised the overriding plate at subduction initiation. The juxtaposition of a relatively buoyant remnant arc terrane adjacent to an oceanic plate was more favourable for subduction initiation than would have been the case if both downgoing and overriding plates had been oceanic.OI and YK appreciate JAMSTEC and J-DESC for their funding to join the expedition and post cruise research. IPS thanks UK-NERC for support for participation of the IODP cruise and part of the postcruise research. OI also used Grant-in-Aid (B) (No. 25287133) for shore-based research

    Effect of extracted garlic powder ingestion for two months on exercise-induced immunological responses

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    Introduction. Exhaustive exercise is associated with an increased risk of upper respiratory tract infection. Previously, allicin supplementation has been reported to reduce the incidence of common cold symptoms and production of exercise-induced interleukin (IL)-6. However, it is not clear if daily ingestion of the edible portion of whole garlic (Allium sativum) alters the exercise-induced immunological response. The present study investigated the effects of extracted garlic powder ingestion for 2 months on immune cell counts, natural killer cell activity (NKCA), as well as changes in cytokines, cortisol, and lactic acid in response to high-intensity cycling exercise. Methods. The present study employed a before-after study design. Six sedentary male participants (age, 22.0±0.3 years) consumed extracted garlic powder for 2 months, and underwent 45 minutes of cycling exercise at 80% of the heart rate reserve once before and once after the supplementation period. A thousand milligrams of extracted garlic powder, comparable to 6 g (1 clove) of raw garlic, was ingested every day. Blood samples were obtained at the following five time points: before exercise, 0 min, 30 min, 60 min, and 120 min after exercise. We measured NKCA, leukocyte counts, neutrophil counts, lymphocyte counts, as well as levels of serum IL-6, IL-10, cortisol, and lactic acid. Repeated measures ANOVA was used for statistical analyses. When interaction effects were significant, measurement values at the various time points were compared between pre- and post-supplementation period using the paired t-test. Changes were deemed statistically significant when p\u3c0.05. Results. We observed no significant difference in pre-exercise measurements between pre- and post-supplementation periods. In addition, we found no significant interaction effect for leukocytes, neutrophils, NKCA, IL-10, and cortisol. However, we did identify a significant interaction effect for lymphocytes, IL-6, and lactic acid (p=0.033, p=0.030, and p\u3c0.001, respectively). Lymphocyte counts were significantly lower post-supplementation relative to pre-supplementation immediately after exercise (p=0.014). In addition, IL-6 was significantly lower post-supplementation relative to pre-supplementation immediately and 30 minutes after exercise (p=0.015 and p=0.018, respectively). Lactic acid levels were significantly lower post-supplementation relative to pre-supplementation immediately after exercise (p=0.018). Conclusions. The extracted garlic powder did not significantly influence exercise-induced responses by leukocytes, neutrophils, NKCA, IL-10, or cortisol. However, exercise-induced responses by lymphocytes, IL-6, and lactic acid were suppressed after ingestion of extracted garlic powder. Thus, daily ingestion of the edible portion of whole garlic may suppress exercise-induced immunological responses and lactic acid levels
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