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The adsorption and desorption of cesium onto layered minerals, zeolite and geochemical reference samples were studied. 0.5 g of bentonite and mica were able to adsorb 71.2 and 51.5 mg of cesium, respectively, from 50 mL of deionized water containing 200 mg/L of cesium under neutral pH condition. These amounts of cesium adsorption were greater than those reported for vermiculites (8.9 and 5.6 mg, respectively). Additionally, the cesium adsorption on mica and vermiculite remained essentially unchanged under seawater conditions, but it decreased drastically on zeolite. The cesium desorption from the layered minerals was promoted by the addition of ammonium ions, namely trioctylmethylammonium chloride and zephiramine. These ammonium ions desorb cesium from the interlayers of the minerals without destroying the mineral structure. The cesium desorption procedure using quaternary ammonium ions would be extremely useful for decontamination of soil containing the layered minerals with adsorbed radioactive cesium.
A new target design is presented to model high-energy radiative accretion shocks in polars. In this paper, we present the experimental results obtained on the GEKKO XII laser facility for the POLAR project. The experimental results are compared with 2D FCI2 simulations to characterize the dynamics and the structure of plasma flow before and after the collision. The good agreement between simulations and experimental data confirms the formation of a reverse shock where cooling losses start modifying the post-shock region. With the multi-material structure of the target, a hydrodynamic collimation is exhibited and a radiative structure coupled with the reverse shock is highlighted in both experimental data and simulations. The flexibility of the laser energy produced on GEKKO XII allowed us to produce high-velocity flows and study new and interesting radiation hydrodynamic regimes between those obtained on the LULI2000 and Orion laser facilities.
For the improvement of oxidation resistance of Nb-based alloys, PdAl-B2 is expected as Al reservoir for Al2O3 surface layer because it is in equilibrium with Nbss (bcc) phase. However, PdAl forms cracks during casting caused by B2 -> β’ transformation. To suppress B2 -> β’ transformation, Rh, Ru and Ir were chosen as additive elements. It is found that bcc / B2 two-phase field in Nb-Pd-Ir-Al system is limited to be small fraction of Ir, while (Pd,Rh)Al-B2 is in equilibrium with bcc solid solution in a wide composition range and addition of Rh prevents occurrence of B2 -> β’ transformation. Composition range of (Pd,Ru)Al-B2 in equilibrium with bcc phase is wider than (Pd,Ir)Al-B2 but narrower than (Pd,Rh)Al-B2. Rh and Ru addition are also beneficial for improving eutectic temperature of Nb-bcc / B2 aluminide two-phase alloys.
In order to understand enhanced mechanical properties of magnesium-yttrium (Mg-Y) alloys, applied stresses which were required to operate independent plastic deformation mechanisms on various stress axes were evaluated. Moreover, for this analysis, mechanical tests including newly-established testing method “pure-shear test” were conducted to evaluate Critical Resolved Shear Stresses (CRSSes) for various plastic deformation mechanisms of Mg-Y solid solution alloy single crystals with various Y concentration. Relatively higher solid solution strengthening of dominant plastic deformation mechanisms such as basal slip and extension twin at room temperature, results in increase in the activation of non-basal slip system. By a simple analysis based on von-Mises criterion with experimental CRSS values, it is revealed that enhanced mechanical properties of Mg-Y alloys might be attributed to the decrease of difference in the activity of plastic deformation mechanisms by Y addition.
Butoxybutyl alcohol (BBA) is a possible growth promoter contained in the fermentation and distillation by-products of a traditional Japanese spirit, shochu. In the present study, BBA was synthesized and its chemical structure was confirmed by gas chromatography mass spectrometry and nuclear magnetic resonance. Then, two studies were conducted to investigate the effects of feeding the synthesized BBA on the growth and skeletal muscle proteolysis of broiler chickens. Ross male broiler chickens were divided into two groups, control (basal diet: 219 g crude protein/kg and 12·66 MJ metabolizable energy/kg) and BBA diet (30 mg BBA/kg basal diet), with the experimental diets being provided from 15 to 27 days and 0 to 27 days of age, for Studies 1 and 2, respectively. Butoxybutyl alcohol supplementation increased final body weight in both studies, whereas feed intake was unchanged, thereby indicating significantly increased feed efficiency. Furthermore, the synthesized BBA increased the weights of the pectoralis superficialis and profundus muscles, and the leg. The BBA decreased the Nτ-methylhistidine concentration in the excrement and plasma, which are indices of the rate of skeletal muscle protein degradation. It also decreased the mRNA levels of μ-calpain large subunit, atrogin-1/muscle atrophy F-box (MAFbx), ubiquitin and 20S proteasome C2 subunit. These suggest that growth promotion due to the feeding of synthesized BBA is caused by the suppression of skeletal muscle protein degradation, which is related to a decrease in gene expression in the calpain and ubiquitin–proteasome systems.
The effects of alloying elements (Ni/Ta) on the temperature dependence of yield stress in Co3(Al,W) with the L12 structure have been investigated through compression tests of nearly single-phase polycrystalline alloys in the temperature range between room temperature to 1,473K. Compared with a ternary Co3(Al,W), a Ni/Ta-added Co3(Al,W) alloy exhibits a higher γ΄ solvus temperature and lower onset temperature of the yield stress anomaly (positive temperature dependence of yield stress), suggesting that the CSF energy is increased by Ni/Ta addition. As a consequence, the high-temperature strength in Co3(Al,W) is considerably enhanced.
The existence of Pt7Cu ordering phase (intermetallic compound) was investigated by ab initio calculations and high voltage electron microscopy (HVEM) focusing on irradiation-induced ordering. The Pt7Cu ordering phase (cF32, prototype Ca7Ge) was predicted at 0 K through density functional theory (DFT), and using cluster expansion (CE) method and grand canonical Monte Carlo (GCMC) simulation, the ordering temperature of fcc-based Pt7Cu ordering phase was estimated to be above room temperature. The formation of Pt7Cu ordering phase was confirmed by a short-time irradiation for 3.6×103 s at 600 K. MeV electron irradiation can reduce drastically the annealing time for the ordering in the Pt-Cu alloy system, indicating that the combination of the prediction by ab initio calculations and HVEM can offer the unique opportunity to investigate the existence of ordering phase in alloys.
An overview of the Czech national R&D project HiLASE (High average power pulsed laser) is presented. The project focuses on the development of advanced high repetition rate, diode pumped solid state laser (DPSSL) systems with energies in the range from mJ to 100 J and repetition rates in the range from 10 Hz to 100 kHz. Some applications of these lasers in research and hi-tech industry are also presented.
Although apomixis is the most common form of parthenogenesis in diplodiploid arthropods, it is uncommon in the haplodiploid insect order Hymenoptera. We found a new type of spontaneous apomixis in the Hymenoptera, completely lacking meiosis and the expulsion of polar bodies in egg maturation division, on the thelytokous strain of a parasitoid wasp Meteorus pulchricornis (Wesmael) (Braconidae, Euphorinae) on pest lepidopteran larvae Spodoptera litura (Fabricius) (Noctuidae). The absence of the meiotic process was consistent with a non-segregation pattern in the offspring of heterozygous females, and no positive evidence was obtained for the induction of thelytoky by any bacterial symbionts. We discuss the conditions that enable the occurrence of such rare cases of apomictic thelytoky in the Hymenoptera, suggesting the significance of fixed heterosis caused by hybridization or polyploidization, symbiosis with bacterial agents, and occasional sex. Our finding will encourage further genetic studies on parasitoid wasps to use asexual lines more wisely for biological control.
High-velocity compact clouds (HVCCs) are a population of molecular clouds which have compact appearance (d < 10 pc) and large velocity width (Δ V > 50 km s−1), and are found in the central molecular zone of our Galaxy. We performed a 3 mm band line survey toward CO−0.40−0.22, a spatially unresolved HVCC with an extremely large velocity width (Δ V ≃ 90 km s−1), using the Mopra 22 m telescope. We surveyed the frequency range between 76 GHz and 116 GHz with a 0.27 MHz frequency resolution. We detect at least 54 lines from 32 molecules. Many line profiles show a prominent peak at vLSR ∼ 70 km s−1 with very large velocity width, indicating they are emitted by the HVCC. Detections of largish molecules are indicative of non-equilibrium chemistry. We extracted some prominent lines based on velocity structure, intensity ratios, and PCA analyses. Shock diagnostic lines (SiO, SO, CH3OH, HNCO) and dense gas probes (HCN, HCO+) appear to be prominent. Excitation analysis of CH3OH lines show an enhancement in Trot in the negative high-velocity end of the profile. These results suggest that CO−0.40−0.22 has experienced a shock, acceleration, compression, and heating in the recent past.
Polycondensation reactions between amino acids and phenols are one of the pathways for the formation of humic substances, and clay minerals are able to catalyse these reactions. To investigate the catalytic power of allophane, an allophane fraction (ALF) was separated from weathered pumice (WP) that contained imogolite as an impurity by taking advantage of differences in sedimentation velocity. The iron content in the separated ALF was increased by up to 3.0% compared to that in the starting WP (1.3%), and the ALF was further treated with sodium dithionate and citric acid (ALF-DC) to remove the iron. The catalytic powers of WP, ALF and ALF-DC were evaluated, based on the degree of darkening of reaction mixtures from polycondensation reactions between catechol and tryptophan, model compounds for precursors of humic substances. The catalytic power for ALF was significantly higher than the corresponding values for WP and ALF-DC. This can be attributed to the high iron content of the ALF, which serves as a Lewis acid that can enhance nucleophilic reactions which occur during the polycondensation reactions.
We present the results of the Nobeyama Radio Observatory (NRO) M 33 All Disk (30′ × 30′,
or 7.3 kpc × 7.3 kpc) Survey of Giant Molecular Clouds (NRO MAGiC) based on
12CO(J = 1–0) observations using the NRO 45-m telescope and
12CO(J = 3–2) observations using the ASTE 10-m telescope.
The spatial resolution of the resultant 12CO(J = 1–0) map is
193, corresponding to 81 pc, which is sufficient to identify each Giant Molecular Cloud
(GMC) in the disk. We found clumpy structures with a typical spatial scale of
~100 pc, corresponding to GMCs, and no diffuse, smoothly distributed component
of molecular gas at this sensitivity.
We obtained a map of the molecular fraction,
fmol = ΣH2/(ΣHi + ΣH2),
at a 100-pc resolution. This is the first fmol map covering an
entire galaxy with a GMC-scale resolution. The correlation between
fmol and gas surface density shows two distinct sequences.
The presence of two correlation sequences can be explained by differences in metallicity,
i.e., higher (~2-fold) metallicity in the central region
(r < 1.5 kpc) than in the outer parts. Alternatively,
differences in scale height can also account for the two sequences, i.e.,
increased scale height toward the outer disk.
International collaboration for disaster response is an increasing phenomenon. Japan-United States joint field exercises have been conducted annually since 2004, triggered by an incident in which a US helicopter crashed into a university campus in Okinawa, Japan. The fifth Japan-US disaster field exercise was conducted testing the disaster response of the Okinawa government and US military.
The simulated exercise involved a US Navy aircraft that crashed into a city center in Okinawa, Japan. There were 16 simulated casualties that included US military members and Japanese citizens. The participants in this exercise were US military members, including the Disaster Assistance Response Team (DART) and local rescue and medical teams including the Okinawa Disaster Medical Assistance Team (DMAT). Data were gathered from the joint debriefing session held by both medical teams. Furthermore, interviews with team leaders from both nations were conducted and feedback obtained.
Lack of communication and inaccurate communication remained the root of most problems encountered. There were several miscommunications at the scene due to the language barrier and ignorance of different medical teams' capability and method of practice. Due to the unclear signage of the initial triage zone, another triage zone was developed later by a second medical team. Confusion regarding gathering information and order of transport also was witnessed. The capabilities of team members were not well known between teams, resulting in inappropriate expectations and difficulty in effective cooperation.
Understanding the systems and backgrounds of each medical team is essential. Signs or symbols of key elements including triage areas should be clear, universal, and multilingual. Communication remains the Achilles' heel of multi-national disaster response activities.
In a series of fundamental studies on the cathode active materials for a lithium secondary cell using geometrically well-defined sample electrodes, thin films of spinel LiMn204 on a platinum plate were investigated in this work in an LiCl04/propylene carbonate solution. These pyrolytically prepared films exihibit reversible extraction/insertion behavior for lithium under galvanostatic charge/discharge cycling between 4.3-3.5 V. The chemical diffusion coefficient of lithium in LixMn204 determined by the galvanostatic intermittent titration technique (GITT) was in the order of 10−7-10−10 cm2- s−1 within a spinel single-phase region of 0.6<x<1.0 and increased with increasing x.
In order to develop an air cathode of metal-air batteries, oxygen reduction behavior of gas diffusion-type carbon electrodes loaded with perovskite-type oxides, Lai-xA'xFe03 (A'=Ca, Sr, Ba, 0<x<1.0), was examined in 8 M KOH at 60 °C. Among the oxide catalysts tested, La0.5Sr0.5Fe03 (specific surface area : 21.5 m2.g−1) gave the highest electrode performance. On the basis of electrode reaction kinetics, H2O2 decomposition rates, and temperature programed desorption of oxygen, it was concluded that such a performance was attributable to the active sites of the oxide for the direct 4-electron reduction of oxygen. Moreover, the electrode using Lao.5Sro.5FeO3 was found to be rather stable in a short-term operation for 90 h at 300 mA-cm−2.
The frictional behavior of a C60 monolayer film between graphite substrates is studied using a homebuilt surface force apparatus. The mean frictional force from the C60 monolayers is estimated to be approximately 2mN, which is one-fifth that of C60 thin films. The C60 monolayer films exhibit a low frictional force of 2mN up to one hundred scans under a normal stress of 8MPa, which indicates that the C60 monolayer film is highly promising for use as a lubricant. Key words, C60 monolayer film, Lubrication, Mechanical properties, Micromachines
Ferroelectric tead zirconate titanate, Pb(Zrx Tibx)O3 (hereafter abbreviated as PZT), thin films were prepared by annealing precursor films of multilayered structures composed of alternating layers of PZT aiKL lead titanate (hereafter abbreviated as PT). This method (which we refer to as multi-seeding) was used in order to lower the processing temperature of PZT. The precursor films were prepared from alkoxide precursor solutions. Effects of zirconium to titanium ratios and stacking structures of the multi-layered precursor films on crystallization behavior were studied to improve the electrical properties of the resultant PZT thin films. Layers of PT were inserted between every PZT layer in order to seed the crystallization of the desired perovskite phase. PT has previously been shown to crystallize with a pure perovskite structure at temperatures as low as 450 °C. Precursor layers of PZT with different compositions, ranging from x = 1 to x = 0.53 were prepared. In this process, the compositions of the PZT precursors and/or the stacking structure, as well as the heating schedule, had a large effect on the crystallization behavior. Nucleation control of the PT seeding layer by changing the heating schedules played an important role in preparing perovskite PZT thin films at low temperatures. Dielectric properties of the resultant films depended on the compositions and annealing temperatures. It was demonstrated that the composition of the resultant PZT film was controllable in the multi-seeding process, and that dielectric properties of the resultant films were improved.