239 research outputs found

    Internal framework and geochemistry of the Carboniferous Huaco granite pluton, Sierra de Velasco, NW Argentina

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    The A-type Huaco granite pluton of the Velasco range (Sierras Pampeanas of northwest Argentina) is formed by three coeval granitic facies and contains subordinate coeval-to-late facies, as well as enclaves, dikes and stocks that show different temporal relations, textures and compositions. The dominant facies (Regional Porphyritic Granite; RPG) is a porphyritic two-mica monzo- to syenogranite, with abundant microcline megacrysts up to 12 cm in size. It was emplaced in a dominant extensional setting and has a mainly crustal source but with participation of a mantle-derived component. The RPG transitions towards two coeval and co-genetic granite facies, at its margins (Border Granite; BG) and around Be-pegmatites (Adjacent Porphyritic Granite; APG). These two facies have a finer-grained texture and smaller and less abundant megacrysts. They are also monzo- to syenogranites, but a slight decrease in the biotite/muscovite ratio is observed from the BG to the RPG to the APG. Trace element modeling suggests that the RPG, BG and APG differentiated from the same magma source by fractional crystallization. Temporally older mafic (ME) and felsic (FE) enclaves are common in the pluton. The ME can be considered partially assimilated remnants of a mafic component in the genesis of the RPG, whereas the FE seem to be remnants of premature aplites. Other subordinate rocks intrude the RPG and are, hence, temporally younger: felsic dikes (FD), dioritic dikes (DD) and equiganular granites (EqG) are clearly posterior, whereas coeval-to-late Be-pegmatites (BeP) and orbicular granites (OG) formed during the final stages of crystallization of the pluton. The BeP, OG and FD indicate the presence of abundant water and volatiles. The EqG form small stocks that intrude the RPG and were possibly originated from purely crustal sources. The DD probably correspond to a younger unrelated episode of mafic magmatism.Fil: Sardi, Fernando Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; ArgentinaFil: Grosse, Pablo. Fundación Miguel Lillo. Dirección de Geología. Instituto de Minerología y Petrografia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Murata, Mamoru. Naruto University; JapónFil: Lozano Fernández, Rafael Pablo. Instituto Geológico y Minero de España; Españ

    Survival Strategy of <i>Escherichia coli</i> in Stationary Phase: Involvement of σE-Dependent Programmed Cell Death

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    In a natural habitat, microbes respond to alterations in the amounts of nutrients or to stresses such as osmotic stress and stresses caused by low or high pH, salt, heat, and antibiotics by changing their mode for proliferation or survival. Similarly, Escherichia coli cells in a test tube change the growth mode according to environmental conditions when they enter a stationary phase. Until a sufficient supply of nutrients, the organism survives under such stressful and nutrient-limited conditions by altering gene expression to be more protective against such conditions. The definite trigger of the onset of stationary phase is still unclear, but several lines of evidence indicate that the regulation mechanism is very complicated and involves several transcriptional factors including alternative sigma factors, σE and σS. In addition, E. coli cells behave as a community of species and give rise to programmed cell death (PCD) for ensuring survival by controlling the cell number and supplying nutrients to sibling cells in long-term stationary phase (LTSP). The main PCD is probably performed by σE in E. coli. In this chapter, physiological functions of σE and PCD are introduced and reviewed and their possible involvement in survival mechanisms in stationary phase, especially LTSP, is shown

    ナルト キョウイク ダイガク チガク キョウシツ ムラタ ケンキュウシツ ショウシ

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    Department of geosciences of Naruto University was founded in 1986 and will be closed in 2019. A short history and academic lists of Murata Laboratory, which was founded in 1991, keep a record as the last Laboratory

    Mesozoic-Cenozoic mafic magmatism in Sanandaj-Sirjan Zone, Zagros Orogen (Western Iran): geochemical and isotopic inferences from Middle Jurassic and Late Eocene gabbros

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    One of the consequences of Neo-Tethys ocean subduction beneath the Central Iranian Micro-continent (CIMC) is the development of rare gabbroic intrusions in the Malayer-Boroujerd Plutonic Complex (MBPC) located in the Sanandaj-Sirjan Zone (SaSZ) of the Zagros Orogenic belt. The MBPC is a suite of extensive felsic and lesser mafic magmatic products in the northern SaSZ with geochemical signatures of arc-like magmatism during the Middle Jurassic (Ghorveh-Aligudarz arc) and intraplate type in the Late Eocene. Middle Jurassic gabbros (non-cumulate and cumulate) have low-Ti concentrations (&lt; 1 wt. %) and quite uniform isotopic compositions (initial 87Sr/86Sr: 0.7035‒0.70593 and εNd(t): - 6.18‒-0.7), enriched LILE relative to HFSE, variable fractionation between the LREE and HREE ((La/Yb)cn: 2.27‒7.45) and both negative to positive Eu anomalies. These distinctive features of arc-type magmatism are consistent with a subduction-modified mantle source for these rocks. Trace element and REE models indicate ~ 15% melting of a metasomatized amphibole-bearing garnet-spinel lherzolite (garnet:spinel ~ 7:3) in the sub-arc mantle wedge. The cumulate gabbros and non-cumulates belong to common liquid line of descent, with complementary trace element patterns. Much of the variation between samples can be modeled by fractional crystallization (FC) of a common parent; only one cumulate gabbro from this suite exhibits isotopic evidence of contamination, probably by Rb-depleted crustal materials. The Late Eocene gabbros have relatively high Ti (&gt;1 wt. %) and display isotopically depleted Sr-Nd values (initial 87Sr/86Sr: 0.7044-0.7087, εNd(t): 1.9-+3.2, barring one crustally contaminated sample). OIB-like trace element characteristics such as enriched HFSE, and only minor enrichment of LILE and LREE, reflect a within-plate character and asthenospheric source. Trace element modeling indicates small degree melting (fmelting: 0.05) of upper mantle lherzolite (garnet:spinel ~ 3:1) followed by higher degree melting (fmelting: 0.15) at shallower depths (garnet:spinel ~4.5:2). The Eocene parental magma underwent FC of olivine and clinopyroxene. We propose that Eocene asthenospheric upwelling was triggered by slab tearing in response to slab-rollback, which is elsewhere reported to have triggered a 'flareup' of extension-related magmatism across Iran. Three stages of tectonomagmatic evolution in the Ghorveh-Aligudarz arc segment of the N-SaSZ are represented by: 1) arc-like magmatism during active subduction of the Neo-Tethys seaway at Middle Jurassic, 2) magmatic quiescence during an interval of shallow-angle or highly oblique subduction during the Cretaceous‒Paleocene, and 3) asthenosphere melting during slab tearing shortly before the onset of the Arabia-Eurasia collision

    Subduction-related mafic to felsic magmatism in the Malayer-Boroujerd plutonic complex, western Iran

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    The Malayer–Boroujerd plutonic complex (MBPC) in western Iran, consists of a portion of a magmatic arc built by the northeast verging subduction of the Neo-Tethys plate beneath the Central Iranian Microcontinent (CIMC). Middle Jurassic-aged felsic magmatic activity in MBPC is manifested by I-type and S-type granites. The mafic rocks include gabbroic intrusions and dykes and intermediate rocks are dioritic dykes and minor intrusions, as well as mafic microgranular enclaves (MMEs). MBPC Jurassic-aged rocks exhibit arc-like geochemical signatures, as they are LILE- and LREE-enriched and HFSE- and HREE-depleted and display negative Nb–Ta anomalies. The gabbro dykes and intrusions originated from metasomatically enriched garnet-spinel lherzolite [Degree of melting (fmel) ~ 15%] and exhibit negative Nd and positive to slightly negative εHf(T) (+ 3.0 to − 1.6). The data reveal that evolution of Middle Jurassic magmatism occurred in two stages: (1) deep mantle-crust interplay zone and (2) the shallow level upper crustal magma chamber. The geochemical and isotopic data, as well as trace element modeling, indicate the parent magma for the MBPC S-type granites are products of upper crustal greywacke (fmel: 0.2), while I-type granites formed by partial melting of amphibolitic lower crust (fmel: 0.25) and mixing with upper crustal greywacke melt in a shallow level magma chamber [Degree of mixing (fmix): 0.3]. Mixing between andesitic melt leaving behind a refractory dense cumulates during partial crystallization of mantle-derived magma and lower crustal partial melt most likely produced MMEs (fmix: 0.2). However, enriched and moderately variable εNd(T) (− 3.21 to − 4.33) and high (87Sr/86Sr)i (0.7085–0.7092) in dioritic intrusions indicate that these magmas are likely experienced assimilation of upper crustal materials. The interpretations of magmatic activity in the MBPC is consistent with the role considered for mantle-derived magma as heat and mass supplier for initiation and evolution of magmatism in continental arc setting, elsewhere

    自然災害(地震・火山噴火・水害)の減災教育用実験教材の開発

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    Natural disasters often occur in the world. The education of prevention and reduction of the disasters is one of the most important targets in schools and lifelong learning. The education has been performed as ESD although it was finished in 2014. As EDS for 2030 is promoted by UNESCO to achieve SDGs (the sustainable development goals), the education of prevention and reduction natural disasters is still important. Experiments based on the mechanisms of natural disasters such as earthquake, volcanic eruption and floodare introduced with the brief professional explanations

    月は西から昇る : 鳴門教育大学生驚愕の真実

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    初等理科教育論は2年次学生を対象に,物理・化学・生物・地学の4分野の模擬授業とそれに関する現職教員の講義からなる。本年度は,大学院生22名を2班に,学部生111名を8班に分けて実施した。模擬授業は2名から4名が模擬授業を担当し,残りは児童役を担当した。地学分野では,小学校6学年理科の「月の満ち欠け」に関する模擬授業を行った。模擬授業後に,当該分野の中学校入試問題を課した。履修大学院生に現職教員はおらず,他大学卒業生であり,その正答率は14.3%であった。学部生の正答率は25.0%であり,10ポイント高かった。理系コース所属学部生35名の正答率は21.4%であり,文系学生よりも成績が悪かった。学部学生の半数は,シドニーの月の満ち欠けが答えられず,月は西から昇ると答えた。The lecture "science education of elementary schools" for the second grade students consists of 5 classes; simulated classes on physics, chemistry, biology and geosciences and lecture class by incumbent elementary school teachers. 22 graduated students who had graduated from other universities and 111 undergraduate students were divided into 2 and 8 groups, respectively, and 10 groups rotated among 5 classes. 2 to 4 students gave simulated lectures and other students played pupils. In geosciences, 10 groups gave simulated classes on the wax and wane, and then all attendants were examined on the examinations for junior high school entrance. The average percentage of correct answers of graduated students scored 14.5% and those of undergraduate did 25.0% showing 10 points higher. The percentage of 35 students in sciences yielded 21.4% showing worse score than those of humanities. Half the students could not answer the wax and wane in Sydney, and believed that the moon rose in the west there

    Demolition of Reinforced Concrete by Steam Pressure Cracking System

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    The authors developed an environment-friendly demolition mechanical system for a large reinforced concrete structure for an actual site. The steam pressure cracking agent (SPC, non-explosive) is a method that can safely and quickly separate concrete because it produces lesser vibration and sound than the blasting method, which uses explosives. The authors showed that the direction of cracking can be controlled by an induction hole. The principle of control is that the elastic wave of the compression stress generated from the SPC reaction changes to a tensile elastic wave at the induction hole, which initiates a crack. Furthermore, in the SPC method, a large amount of concrete powder generated by the explosion method was not produced, and there was no risk of secondary contamination by fine concrete powder. The area over which the crack propagated depends on the energy generated from the SPC. The relationship between the two is linear. For reinforced concrete, the energy of the SPC is used for both the destructive energy of the concrete and the energy of the cutting of the reinforcing steel bar, which quickly breaks with low energy. By applying an SPC to dismantle large reinforced concrete structures, controlled cracking can be achieved safely and quickly without any environmental pollution. A fracturing method using a SPC is an effective method for the decommissioning of nuclear power plants and the dismantling of concrete structures. In this report, we report a remote drilling system that can be used to remotely install loading holes and guiding holes for the SPC and perform effective controlled fracturing

    VLBI Detections of Parsec-Scale Nonthermal Jets in Radio-Loud Broad Absorption Line Quasars

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    We conducted radio detection observations at 8.4 GHz for 22 radio-loud broad absorption line (BAL) quasars, selected from the Sloan Digital Sky Survey (SDSS) Third Data Release, by a very-long-baseline interferometry (VLBI) technique. The VLBI instrument we used was developed by the Optically ConnecTed Array for VLBI Exploration project (OCTAVE), which is operated as a subarray of the Japanese VLBI Network (JVN). We aimed at selecting BAL quasars with nonthermal jets suitable for measuring their orientation angles and ages by subsequent detailed VLBI imaging studies to evaluate two controversial issues of whether BAL quasars are viewed nearly edge-on, and of whether BAL quasars are in a short-lived evolutionary phase of quasar population. We detected 20 out of 22 sources using the OCTAVE baselines, implying brightness temperatures greater than 10^5 K, which presumably come from nonthermal jets. Hence, BAL outflows and nonthermal jets can be generated simultaneously in these central engines. We also found four inverted-spectrum sources, which are interpreted as Doppler-beamed, pole-on-viewed relativistic jet sources or young radio sources: single edge-on geometry cannot describe all BAL quasars. We discuss the implications of the OCTAVE observations for investigations for the orientation and evolutionary stage of BAL quasars.Comment: 10 pages, no figure, 3 tables, accepted for publication in PAS

    Elastic Wave Property of Concrete Decomposed by Steam Pressure Cracking Agent

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    A steam pressure cracking (SPC) agent is a method that can dismantle concrete safely and quickly. In previous studies, the authors showed that the direction of the crack could be controlled by the tensile stress at the induction holes and not by the compressive stress at the SPC hole. We demonstrate that the compression elastic wave changes to a tensile wave when the wave is reflected at the free surface of the induction hole. We also examined the properties of the concrete by developing an elastic wave measuring system that is difficult to break down even in high-temperature, wet, and radiation environment. The elastic wave velocity change in the four concrete types was less than 4%. It was found that the standard deviation value, σ, changed four times. Therefore, it is possible to determine the deterioration of the internal structure of concrete using the standard deviation value σ, which indicates the dispersion of the elastic wave velocity
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