351 research outputs found

    Selective production of valuable chemicals from biomass by two-step conversion combining pre-oxidation and hydrothermal degradation

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    Biomass is getting notable as a new energy resource to replace fossil resources and to restrain CO₂ emission recently. However, it is obvious that the energy use of biomass is unsuitable for its limit of available amounts. Consequently, we investigated the possibility of new refinery scheme of biomass to utilize biomass as an alternative raw material to fossil resources with suggested two-step treatment method. We oxidized cellulose and biomass with H₂O₂ first and put the residue into hydrothermal condition to obtain some specific chemicals. Through the first oxidation of cellulose, 0.26 g/g-cellulose of organic acid was obtained, and 0.35 g/g-cellulose of oxalic acid was obtained under the catalytic condition. Both cedar and cellulose decreased their crystallinity through the first oxidation and increased their reactivity, we could obtain hydroxymethylfurfural(HMF) from cellulose and biomass through the hydrothermal degradation, 0.11 g/g-cellulose and 0.12 g/g-cedar respectively

    Effects of Nutrient Solution Concentration on Cut Flower Yield, Quality and Characteristics of Seasonal Nutrient Absorption of Spray Carnation Grown by Cultivation in Drip Fertigation

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    Effects of nutrient solution concentration on cut flower yield, quality and characteristics of seasonal nutrient absorption of spray carnation ‘Barbara’ grown by cultivation in drip fertigation were investigated. 'Barbara' was grown with a nutrient solution (N:15%, P:6.5%, K:12.5%, Ca:3.6%, Mg:0.9%), at three concentration levels which were high concentration (1,000 times), middle concentration (1,500 times) and low concentration (3,000 times). The daily amount of nutrient solution was ranged from 0.0mm to 13.9mm. The total cut flower yield of middle concentration and high concentration were bigger than that of low concentration. The weight of the second cut flower of low concentration was decreased as compared to that of middle concentration and high concentration. Nitrogen (N) and potassium (K) in the plant nutrient ratio were decreased as the increase of dry matter and phosphorus (P) was increased at autumn and spring. With a reduction in the soil nutrient contents, Nitrogen and potassium in the plant nutrient ratio of low concentration were decreased. Nitrogen and phosphorus in the soil nutrient contents of high concentration were increased at the end of cultivation. In the total nutrient absorbed amount of middle concentration, 2,807.9 mg nitrogen, 493.5 mg phosphorus, 3,667.4 mg potassium, 1,615.8 mg calcium (Ca) and 320.9 mg magnesium (Mg) were absorbed per plant. In spring, the ratio of nitrogen absorbed amount to nutrients absorbed amount was increased 1.3 times. Phosphorus ratio and phosphorus absorbed amount in spray carnation were fewer than that of standard carnation. There were no differences in total nitrogen, potassium, calcium and magnesium absorption between spray carnation and standard carnation.スプレーカーネーションのかん水同時施肥法における養分吸収特性を‘バーバラ’で調査した.窒素:リン(P):カリウム(K):カルシウム(Ca):マグネシウム(Mg)の含有率(%)が15:6.5:12.5:3.6:0.9の液肥を,低濃度(3,000倍),中濃度(1,500倍),高濃度(1,000倍)の3水準で,毎日0.0~13.9㎜ずつ点滴給液した.切り花収量は中濃度区と高濃度区が多く,切り花品質は2番花において低濃度区の切り花重が減少した.植物体の窒素およびカリウム含有率は乾物増加量が増大するにつれて低下し,リンは秋期と春期に減少した.低濃度区の窒素,カリウムの含有率は土壌養分含有量の減少にともない,低下した.高濃度区では土壌の窒素およびリン含有量が栽培終了時に大幅に増大した.中濃度での給液における1株当たりの総養分吸収量は窒素が2,807.0㎎,リンが493.5㎎,カリウムが3,667.4㎎,カルシウムが1,615.8㎎,マグネシウムが320.9㎎であった.リン,カリウム,カルシウム,マグネシウムの窒素に対する吸収割合はいずれも春期に約1.3倍に上昇した.スタンダードカーネーションとの比較では,スプレーカーネーションでは,ややリンの植物体含有率と吸収量が少ないが,窒素,カリウム,カルシウム,マグネシウムの植物体含有率および吸収量には,ほとんど差がなかった

    Planar CuO_2 hole density estimation in multilayered high-T_c cuprates

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    We report that planar CuO_2 hole densities in high-T_c cuprates are consistently determined by the Cu-NMR Knight shift. In single- and bi-layered cuprates, it is demonstrated that the spin part of the Knight shift K_s(300 K) at room temperature monotonically increases with the hole density pp from underdoped to overdoped regions, suggesting that the relationship of K_s(300 K) vs. p is a reliable measure to determine p. The validity of this K_s(300 K)-p relationship is confirmed by the investigation of the p-dependencies of hyperfine magnetic fields and of spin susceptibility for single- and bi-layered cuprates with tetragonal symmetry. Moreover, the analyses are compared with the NMR data on three-layered Ba_2Ca_2Cu_3O_6(F,O)_2, HgBa_2Ca_2Cu_3O_{8+delta}, and five-layered HgBa_2Ca_4Cu_5O_{12+delta}, which suggests the general applicability of the K_s(300 K)-p relationship to multilayered compounds with more than three CuO_2 planes. We remark that the measurement of K_s(300 K) enables us to separately estimate p for each CuO_2 plane in multilayered compounds, where doped hole carriers are inequivalent between outer CuO_2 planes and inner CuO_2 planes.Comment: 7 pages, 5 figures, 2 Tables, to be published in Physical Review

    Evaluation of heterogeneity dose distributions for Stereotactic Radiotherapy (SRT): comparison of commercially available Monte Carlo dose calculation with other algorithms

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to compare dose distributions from three different algorithms with the x-ray Voxel Monte Carlo (XVMC) calculations, in actual computed tomography (CT) scans for use in stereotactic radiotherapy (SRT) of small lung cancers.</p> <p>Methods</p> <p>Slow CT scan of 20 patients was performed and the internal target volume (ITV) was delineated on Pinnacle<sup>3</sup>. All plans were first calculated with a scatter homogeneous mode (SHM) which is compatible with Clarkson algorithm using Pinnacle<sup>3 </sup>treatment planning system (TPS). The planned dose was 48 Gy in 4 fractions. In a second step, the CT images, structures and beam data were exported to other treatment planning systems (TPSs). Collapsed cone convolution (CCC) from Pinnacle<sup>3</sup>, superposition (SP) from XiO, and XVMC from Monaco were used for recalculating. The dose distributions and the Dose Volume Histograms (DVHs) were compared with each other.</p> <p>Results</p> <p>The phantom test revealed that all algorithms could reproduce the measured data within 1% except for the SHM with inhomogeneous phantom. For the patient study, the SHM greatly overestimated the isocenter (IC) doses and the minimal dose received by 95% of the PTV (PTV95) compared to XVMC. The differences in mean doses were 2.96 Gy (6.17%) for IC and 5.02 Gy (11.18%) for PTV95. The DVH's and dose distributions with CCC and SP were in agreement with those obtained by XVMC. The average differences in IC doses between CCC and XVMC, and SP and XVMC were -1.14% (p = 0.17), and -2.67% (p = 0.0036), respectively.</p> <p>Conclusions</p> <p>Our work clearly confirms that the actual practice of relying solely on a Clarkson algorithm may be inappropriate for SRT planning. Meanwhile, CCC and SP were close to XVMC simulations and actual dose distributions obtained in lung SRT.</p
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