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51.
Bhadravathi Eswara Lokesh Zubaidah Aimi Abdul Hamid Takamitsu Arai Akihiko Kosugi Yoshinori Murata Rokiah Hashim Othman Sulaiman Yutaka Mori Kumar Sudesh 《洁净——土壤、空气、水》2012,40(3):310-317
Utilization of cheap renewable carbon feedstock for polyhydroxyalkanoate (PHA) production not only brings down its production cost but also ensures sustainability. The scope of this study was to evaluate the potential of sap extracted from felled oil palm trunk (OPT) as a novel inexpensive renewable carbon source for PHA production. OPT sap was found to be nutritionally rich and contained various fermentable sugars (5.5% w/v) as its major constituent. Termite gut isolate, Bacillus megaterium MC1 grew profoundly in mineral medium with OPT sap as carbon source and a cell density of 10.9 g/L was attained after 16 h of cultivation in shake flask cultures. A maximum poly‐3‐hydroxybutyrate [P(3HB)] content (% cell dry weight; CDW) of 30 wt% and a P(3HB) concentration of 3.28 g/L was recorded. Additionally, OPT sap extracted from younger tree trunks with prolonged storage had higher sugar content (10.8% w/v) and, when used as a growth medium without the addition of any nutrients, supported bacterial growth comparable to commercially available media. 相似文献
52.
Yui Kouketsu Tomoyuki Mizukami Hiroshi Mori Shunsuke Endo Mutsuki Aoya Hidetoshi Hara Daisuke Nakamura Simon Wallis 《Island Arc》2014,23(1):33-50
The Raman spectra of carbonaceous material (CM) from 19 metasediment samples collected from six widely separated areas of Southwest Japan and metamorphosed at temperatures from 165 to 655°C show systematic changes with metamorphic temperature that can be classified into four types: low‐grade CM (c. 150–280°C), medium‐grade CM (c. 280–400°C), high‐grade CM (c. 400–650°C), and well‐crystallized graphite (> c. 650°C). The Raman spectra of low‐grade CM exhibit features typical of amorphous carbon, in which several disordered bands (D‐band) appear in the first‐order region. In the Raman spectra of medium‐grade CM, the graphite band (G‐band) can be recognized and several abrupt changes occur in the trends for several band parameters. The observed changes indicate that CM starts to transform from amorphous carbon to crystallized graphite at around 280°C, and this transformation continues until 400°C. The G‐band becomes the most prominent peak at high‐grade CM suggesting that the CM structure is close to that of well‐crystallized graphite. In the highest temperature sample of 655°C, the Raman spectra of CM show a strong G‐band with almost no recognizable D‐band, implying the CM grain is well‐crystallized graphite. In the Raman spectra of low‐ to medium‐grade CM, comparisons of several band parameters with the known metamorphic temperature show inverse correlations between metamorphic temperature and the full width at half maximum (FWHM) of the D1‐ and D2‐bands. These correlations are calibrated as new Raman CM geothermometers, applicable in the range of c. 150–400°C. Details of the methodology for peak decomposition of Raman spectra from the low to medium temperature range are also discussed with the aim of establishing a robust and user‐friendly geothermometer. 相似文献
53.
Takehiko Mori Yasuaki Sudo Tomoki Tsutsui Shin Yoshikawa 《Bulletin of Volcanology》2008,70(9):1031-1042
Isolated-type tremors having two events with different dominant frequencies are characteristic seismological phenomena observed
during the fumarolic activity stage at Aso Volcano. These isolated tremors are called hybrid tremors (HBT) and comprise two
parts: an initial part named the “HF-part” with a dominant frequency in the high-frequency region (approximately 10 Hz) and
the following part named the “LF-part” with a dominant frequency in the low-frequency region (approximately 2 Hz). The LF-part
is observed after the HF-part, and the HBT is accompanied by a long-period tremor (LPT). Hypocenters and source parameters
are estimated using seismograms recorded at 64 stations around Nakadake crater. The amplitude distributions of all HF-parts
have almost similar trends. Similarly, the amplitude distributions of all LF-parts have almost similar trends. However, the
amplitude distributions of HF- and LF-parts are not similar. From these results, we proposed that the hypocenters and source
parameters of HF- and LF-parts are not common, but each of them have common hypocenters and source parameters. The hypocenter
region of HF-parts was estimated to be just beneath the fumarole region south of the 1st crater: the volume fluctuation is
the major source factor. The hypocenter region of LF-parts is estimated to be at a depth of approximately 300 m beneath the
first crater: the strike–slip component is the major source parameter. The hypocentral depth of LF-parts is located at the
upper end of the crack estimated to be the source of the LPTs. The LPTs and HBTs are observed almost simultaneously. We consider
that volcanic fluid is involved in the source mechanisms of both HBT and LPT. 相似文献
54.
Detrital zircon multi‐chronology,provenance, and low‐grade metamorphism of the Cretaceous Shimanto accretionary complex,eastern Shikoku,Southwest Japan: Tectonic evolution in response to igneous activity within a subduction zone 下载免费PDF全文
Hidetoshi Hara Yoshihiro Nakamura Kousuke Hara Toshiyuki Kurihara Hiroshi Mori Hideki Iwano Tohru Danhara Shuhei Sakata Takafumi Hirata 《Island Arc》2017,26(6)
Detrital zircon multi‐chronology combined with provenance and low‐grade metamorphism analyses enables the reinterpretation of the tectonic evolution of the Cretaceous Shimanto accretionary complex in Southwest Japan. Detrital zircon U–Pb ages and provenance analysis defines the depositional age of trench‐fill turbidites associated with igneous activity in provenance. Periods of low igneous activity are recorded by youngest single grain zircon U–Pb ages (YSG) that approximate or are older than the depositional ages obtained from radiolarian fossil‐bearing mudstone. Periods of intensive igneous activity recorded by youngest cluster U–Pb ages (YC1σ) that correspond to the younger limits of radiolarian ages. The YC1σ U–Pb ages obtained from sandstones within mélange units provide more accurate younger depositional ages than radiolarian ages derived from mudstone. Determining true depositional ages requires a combination of fossil data, detrital zircon ages, and provenance information. Fission‐track ages using zircons estimated YC1σ U–Pb ages are useful for assessing depositional and annealing ages for the low‐grade metamorphosed accretionary complex. These new dating presented here indicates the following tectonic history of the accretionary wedge. Evolution of the Shimanto accretionary complex from the Albian to the Turonian was caused by the subduction of the Izanagi plate, a process that supplied sediments via the erosion of Permian and Triassic to Early Jurassic granitic rocks and the eruption of minor amounts of Early Cretaceous intermediate volcanic rocks. The complex subsequently underwent intensive igneous activity from the Coniacian to the early Paleocene as a result of the subduction of a hot and young oceanic slab, such as the Kula–Pacific plate. Finally, the major out‐of‐sequence thrusts of the Fukase Fault and the Aki Tectonic Line formed after the middle Eocene, and this reactivation of the Shimanto accretionary complex as a result of the subduction of the Pacific plate. 相似文献
55.
The sector polarity of the interplanetary magnetic field has been inferred daily for the period 1971–1973, using ground level cosmic ray observations. The method depends on the sectors directed towards and away from the Sun being associated with different characteristic variations of the cosmic ray north-south asymmetry. The analysis has a simple basis. The difference between the north and south daily mean intensities of directional telescopes at a single observing station is determined and its value relative to the 27-day average is calculated. The sign (negative or positive) of the value thus derived corresponds to the sector polarity on a daily basis. Good (~76%) agreement is obtained between the polarities inferred indirectly by the present method and those observed directly with the spacecraft magnetometers. We therefore suggest that cosmic ray observations can be used for inferring the sector polarity of the magnetic field in interplanetary space. 相似文献
56.
Masamitsu Fujimoto Nobuhito Ohte Masatoshi Kawasaki Ken'ichi Osaka Masayuki Itoh Izumi Ohtsuka Masami Itoh 《水文研究》2016,30(4):558-572
Groundwater movements in volcanic mountains and their effects on streamflow discharge and representative elementary area (REA) have remained largely unclear. We surveyed the discharge and chemical composition of spring and stream water in two catchments: the Hontani river (NR) catchment (6.6 km2) and the Hosotani river (SR) catchment (4.0 km2) at the southern part of Daisen volcano, Japan. Daisen volcano is a young volcano (17 × 103 years) at an early stage of erosion. Our study indicated that deep groundwater that moved through thick lava and pyroclastic flows and that could not be explained by shallow movements controlled by surface topography contributed dominantly to streamflow at larger catchment areas. At the NR catchment, the deep groundwater contribution clearly increased at a catchment boundary defined by an area of 3.0 km2 and an elevation of 800 m. At the SR catchment, the contribution deep groundwater to the stream also increased suddenly at a boundary threshold of 2.0 and 700 m. Beyond these thresholds, the contributions of deep bedrock groundwater remained constant, indicating that the REA is between 2 and 3 km2 at the observed area. These results indicate that the hydrological conditions of base flow were controlled mainly by the deep bedrock groundwater that moved through thick lava and pyroclastic flows in the undissected volcanic body of the upper part of the catchment. Our study demonstrates that deep and long groundwater movements via a deep bedrock layer including thick deposits of volcanic materials at the two catchments on Daisen volcano strongly determined streamflow discharge instead of the mixing of small‐scale hydrological conditions. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
57.
58.
Daniel H. Doctor Carol Kendall Stephen D. Sebestyen James B. Shanley Nobuhito Ohte Elizabeth W. Boyer 《水文研究》2008,22(14):2410-2423
The stable isotopic composition of dissolved inorganic carbon (δ13C‐DIC) was investigated as a potential tracer of streamflow generation processes at the Sleepers River Research Watershed, Vermont, USA. Downstream sampling showed δ13C‐DIC increased between 3–5‰ from the stream source to the outlet weir approximately 0·5 km downstream, concomitant with increasing pH and decreasing PCO2. An increase in δ13C‐DIC of 2·4 ± 0·1‰ per log unit decrease of excess PCO2 (stream PCO2 normalized to atmospheric PCO2) was observed from downstream transect data collected during snowmelt. Isotopic fractionation of DIC due to CO2 outgassing rather than exchange with atmospheric CO2 may be the primary cause of increased δ13C‐DIC values downstream when PCO2 of surface freshwater exceeds twice the atmospheric CO2 concentration. Although CO2 outgassing caused a general increase in stream δ13C‐DIC values, points of localized groundwater seepage into the stream were identified by decreases in δ13C‐DIC and increases in DIC concentration of the stream water superimposed upon the general downstream trend. In addition, comparison between snowmelt, early spring and summer seasons showed that DIC is flushed from shallow groundwater flowpaths during snowmelt and is replaced by a greater proportion of DIC derived from soil CO2 during the early spring growing season. Thus, in spite of effects from CO2 outgassing, δ13C of DIC can be a useful indicator of groundwater additions to headwater streams and a tracer of carbon dynamics in catchments. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
59.
Recognition of shear heating on a long‐lived major fault using Raman carbonaceous material thermometry: implications for strength and displacement history of the MTL,SW Japan 下载免费PDF全文
The extent to which movement on major faults causes long term shear heating is a contentious issue and an important aspect in the debate about the strength of major faults in the crust. Comparing the results of experimental work on the kinetics of crystallization of carbonaceous material with results of thermal modeling show that the Raman carbonaceous material (CM) geothermometer is well suited to studying shear heating on geological time scales in suitable lithologies exposed around exhumed major fault zones. The Median Tectonic Line (MTL), SW Japan, is the largest on‐land fault in Japan with a length of > 800 km. Application of Raman CM thermometry to pelitic schist adjacent to the fault reveals the presence of a rise in peak temperature of around 60 °C over a distance of around 150 m perpendicular to the MTL fault plane. The spatial association of this thermal anomaly with the fault implies it is due to shear heating. Thermal modeling shows the recorded thermal anomaly and steep temperature gradient is compatible with very high rates of displacement over time scales of a few thousand years. However, the implied displacement rates lie outside those generally observed. An alternative explanation is that an originally broader thermal anomaly that developed during strike slip faulting was shortened due to the effects of normal faulting. Constraints on displacement rate, width of the original anomaly, duration of heating and peak temperature imply a coefficient of friction, μ, greater than 0.4. 相似文献
60.
We report on the diffuse X‐ray emission from the Galactic Centre (GCDX) observed with the X‐ray Imaging Spectrometer (XIS) on board the Suzaku satellite. The highly accurate energy calibration and extremely low background of the XIS provide many new facts on the GCDX. These are (1) the origin of the lines at 6.7 and 7.0 keV is collisional excitation in a hot plasma, (2) the discovery of new SNR and super‐bubble candidates, (3) most of the 6.4 keV line is X‐ray fluorescence, and (4) time variability of the 6.4 keV line is found from the Sgr B2 complex. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献