Study on stretch extinction limits of CH4/CO2 versus high temperature O2/CO2 counterflow non-premixed flames

Extinction limits of counterflow non-premixed flames with normal and high temperature oxidizers were studied experimentally and numerically for development of new-type oxygen-enriched mild combustion furnace. Extinction stretch rates of CH₄/CO₂ (at 300 K) versus O₂/CO₂ flames at oxygen mole fractions of 0.35 and 0.40 and oxidizer temperatures of 300 K, 500 K, 700 K and 1000 K were obtained. Investigation was also conducted for CH₄/N₂ (at 300 K) versus air (O₂/N₂) flames at the same oxidizer temperatures. An effect of radiative heat loss on stretch extinction limits of oxygen-enriched flames and air flames was investigated by computations with optical thin model (OTM) and adiabatic flame model (ADI). The results show influence of radiative heat loss on stretch extinction limits was not significant in relative high fuel mole fraction regions. The extinction curve of the oxygen-enriched flames with oxygen mole fraction of 0.35 was close to that of the air flames at the oxidizer temperature of 300 K. However, the extinction curve of air flames with high temperature oxidizer was comparable with that of oxygen-enriched flames with oxygen mole fraction of 0.40. Scaling analysis based on asymptotic solution of stretch extinction was applied and it was found that stretch extinction limits can be expressed by two terms. The first term is total enthalpy flux of fuel stream based on thermo-physical parameters. The second term is a kinetic term which reflects an effect of the chemical reaction rate on stretch extinction limits. OH radicals which play important roles in chain propagating and main endothermic reactions were used to represent the kinetic term of both oxygen-enriched and air flames. The global rates of OH formation in these two cases were compared to understand the contribution of kinetic term to stretch extinction limits. Variation of extinction curves of oxygen-enriched flames and air flames was well explained by the present scaling analysis. This offers an effective approach to estimate stretch extinction limits of oxygen-enriched flames based on those of air flames at the same oxidizer temperature.     

Inter-laboratory evaluation studies for establishment of notified ELISA methods for allergic substances (peanuts)

Inter-laboratory evaluation studies were conducted for ELISA methods for allergic substances (peanuts). Extracts of biscuit, sauce, chocolate and butter spiked with peanut standard protein at a level of 5-20 ng/mL as sample solutions were analyzed in replicate in 10 laboratories. Coefficients of variation (CVs) of the ELISA methods using a Peanut Protein ELISA Kit (Peanut kit) and a FASTKIT Peanut ELISA kit (Peanut ELISA kit) were mostly below 10%. Mean recoveries of the peanut standard protein from the food extracts were over 40% in the two ELISA methods. Repeatability relative standard deviations of peanut standard protein in four food extracts were in the ranges of 15.2-49.7% and 3.0-28.3% for the Peanut kit and the Peanut ELISA kit, respectively. Reproducibility relative standard deviations of peanut standard protein in four food extracts were 23.5-44.4%, 9.6-28.4% for the Peanut kit and the Peanut ELISA kit, respectively. The detection limits of both ELISA methods were 2-2.5 ng/mL in sample solutions. These results suggested that the notified ELISA methods are reliable and reproducible for the inspection of peanut protein levels in extracts of biscuit, sauce, chocolate and butter.     

全球变暖对日本寒地北海道2030年代水稻生育的影响预测及其对策（网络首发、推荐阅读）

北海道从1980年代开始到2010年代为止,水稻大田栽培期间的5–9月份气温随着年代而不断上升。与最近的2010年代（2010—2019年平均）相比,使用两种2030年代的预测气象,根据以往研究得到的关系方程预测研究了水稻生育。其结果,2030年代比2010年代,插秧日期期限（插秧最早期限）比水稻栽培17个地区平均值要早8~9天。另外,抽穗日期最早期限要早1~5天,抽穗日期最晚期限要晚1~5天,安全抽穗期间要长2~10天,抽穗日期要早1~3天。由于从抽穗日期到最晚抽穗为止要长2~9天,延迟型冷害的发生要略少。关于各生育期的气象,抽穗前24天以后的30天期间的平均气温因为生育早而相同或略低。抽穗前10天以后的40天期间以及抽穗日期以后的40天期间的平均气温略高,日射量略少。因此,糙米产量为96%~98%,要略低,显示潜在产量特性的气候灌浆量指数相同。因为与障碍秕粒发生有关的孕穗期冷害危险期的平均气温略低或基本相同,带来发生冷害的风险。另一方面,引起秕粒发生的低温区的出现频率在地区间具有差异。虽然大米蛋白质含量相同,但直链淀粉含量略低、食味略良。关于米粒外观品质,受害粒比率和着色粒比率没有一定的变化趋势,未熟粒比率略高,大米白度相同,糙米白度略高。通过上述预测研究显示了未来日本寒冷地带水稻生育的技术应对方向。     

Quantitative analyses of the behavior of exogenously added bacteria during an acidulocomposting process

Poly[3-hydroxybutyrate-co-3-hydroxyvalerate(3HV)] was produced in recombinant Escherichia coli LS5218 from ruthenium-catalyzed cellulose hydrolysate and propionate. The strain was found to be resistant to 5-hydroxymethylfurfural (5-HMF), which is a major inhibitory byproduct generated in the cellulose hydrolysis reaction. The 3HV fraction was successfully regulated in the range of 5.6-40 mol%.     

From Terpenoids to Aliphatic Acids: Further Evidence for Late-Instar Switch in Osmeterial Defense as a Characteristic Trait of Swallowtail Butterflies in the Tribe Papilionini

We compared the chemical compositions of the osmeterial secretions of fourth and fifth (last) instars of eight swallowtail species of the tribe Papilionini. Four species (Papilio demoleus, P. polytes, P. paris, and P. macilentus) are Asian Rutaceae-feeding swallowtails. The other four (Chilasa epicydes, C. agestor, P. troilus, and P. glaucus) represent more distant clades within the Papilionini and species with larval hosts in other plant families. We conducted a quantitative analysis for six species, but only qualitative analysis for P. glaucus and C. agestor. In all eight species, regardless of larval host plant, secretions of the fourth instar principally consisted of mono- and sesquiterpene hydrocarbons, whereas those of the fifth instar comprised aliphatic acids and their esters. Consistent with earlier findings, our results suggest that this “heterogeneous” pattern of osmeterial chemistry, not seen in other tribes, may characterize the Papilionini as a whole. Unlike those of most Papilio species, the fourth and fifth instars of Chilasa species resemble each other in body coloration. Thus, the heterogeneous osmeterial pattern is not necessarily associated with color change in papilionid larvae. The major terpenoids identified in fourth instar larval secretions from the six species were α-pinene, sabinene, β-myrcene, limonene, β-phellandrene, (Z)-β-ocimene, (E)-β-ocimene, p-mentha-1,4(8)-diene, β-elemene, β-caryophyllene, (E)-β-farnesene, (3Z,6E)-α-farnesene, (Z)-α-bisabolene, germacrene-A, (E)-α-bisabolene, and germacrene-B. The profiles for individual species differed both qualitatively and quantitatively from one another, and certain species also secreted methyl 3-hydroxy-n-butyrate and oxygenated sesquiterpenes in relatively large proportions. Secretions from fifth instars were composed of varying proportions of isobutyric, 2-methylbutyric, and acetic acids, and methyl and ethyl (minor) esters of both isobutyric and 2-methylbutyric acids. The heterogeneity of osmeterial chemistry in the tribe Papilionini may represent fine-tuning of chemical defense in response to shifting predation pressures as the larvae age and grow.     

PCR-mediated seamless gene deletion and marker recycling in Saccharomyces cerevisiae

Repeated gene manipulations can be performed in yeast by excision of an introduced marker. Cassette modules containing a marker flanked by two direct repeat sequences of hisG or loxP have often been used for marker recycling, but these leave one copy of the repeats in the chromosome after excision. Genomic copies of a repeat can cause increased mistargeting of constructs containing the same repeats or unexpected chromosomal rearrangements via intra- or interchromosomal recombinations. Here, we describe a novel marker recycling procedure that leaves no scar in the genome, which we have designated seamless gene deletion. A 40 base sequence derived from an adjacent region to the targeted locus was placed in an integrating construct to generate direct repeats after integration. Seamless HIS3 deletion was achieved via a PCR fragment that consisted of a URA3 marker attached to a 40 base repeat-generating sequence flanked by HIS3 targeting sequences at both ends. Transformation of the designed construct resulted in his3 disruption and the generation of 40 base direct repeats on both sides of URA3 in the targeted locus. The resulting his3::URA3 disruptants were plated on 5-fluoroorotic acid medium to select for URA3 loss. All the selected colonies had lost URA3 precisely by recombination between the repeats, resulting in his3 deletion without any extraneous sequences left behind in the chromosome.     

Community structure, abundance, and in situ activity of nitrifying bacteria in river sediments as determined by the combined use of molecular techniques and microelectrodes

The community structure, spatial distributions, and in situ activity of ammonia-oxidizing bacteria (AOB) representing the Betaproteobacteria and nitrite-oxidizing bacteria (NOB) representing the genus Nitrospira in three different river sediments with different pollution sources and levels along the Niida River, Hachinohe, Japan, were investigated by the combined use of 16S rRNA gene-cloning analysis, real-time quantitative polymerase chain reaction (RTQ-PCR) assays, and microelectrodes. The goal of this research was to evaluate the contribution of nitrifying activity in the sediment to the overall nitrogen elimination rate in this river. The 16S rRNA gene-cloning analysis revealed that the community structures of AOB and Nitrospira-like NOB are present in three sediments. On the basis of the results of 16S rRNA gene-cloning analysis, the RTQ-PCR assay using a TaqMan probe was developed and optimized for the quantification of the Nitrospira-like NOB. In the sediments, AOB specific 16S rRNA genes were detected in the range of 10(6) to 10(7) copies/cm3 and evenly distributed over the sampled sediment depth (0-5 mm), whereas the Nitrospira-like NOB 16S rRNA gene copy numbers per cm3 were 1-2 orders of magnitude higher than the AOB copy numbers. Under light conditions, intensive oxygenic photosynthesis occurred in the surface and increased the maximal O2 concentration and O2 penetration depth in all sediments. This concomitantly stimulated nitrifying bacteria present in diurnally anoxic deeper zones and expanded nitrification zones, which consequently increased the total NH4+ consumption rate in the sediment (i.e., total NH4+ flux into the sediment). The results suggested that the in situ nitrifying activity was restricted mainly to the surface 2 mm of the sediment and linked with photosynthetic activity, which obviously plays an important role in nitrogen elimination in this river.     

日本の寒地，北海道の稲作限界地帯におけるもち米の硬化性，糊化特性および炊飯米物理特性の年次間地域間差異と発生要因(日语原文)

北海道もち米の6地域4カ年における搗き餅の硬化性と糊化特性を調査した。それらの最小値最大値の差異および変動係数は,年次間が地域間に比べ大きく,年次間と地域間との比の大きさおよび特性間の相関係数から,同比の小さい順にⅠ群の最高粘度とブレークダウン,Ⅱ群の最低粘度,最終粘度およびコンシステンシー,Ⅲ群の糊化開始温度,最高粘度到達温度,最高粘度到達時間および硬化性に分けられた。年次間ではこれら3群の糊化特性の中で,Ⅱ群とⅢ群において硬化性と正の相関関係が認められ,Ⅲ群で最も明確であった。また,出穂後40日間の日平均積算気温（登熟気温）が高いほどⅡ群,Ⅲ群および硬化性が高くなり,その関係はⅢ群と硬化性で最も明確であった。一方,地域間ではこれらの関係が概して明確ではなかった。さらに,精米蛋白質含有率が高いほど,Ⅰ群とⅡ群では年次間と地域間とも,Ⅲ群では年次間のみで,特性値が低くなった。また,炊飯米の物理特性で,平年並みの登熟気温年産と高温の登熟気温年産を比べると,平年登熟年産は柔らかいが粘りが弱く食味が劣るものの,5℃24时間貯蔵より硬くなりにくく柔らかさが持続した。一方,高温登熟年産は粘りが強...     

Training effect on damping capacity in Fe–20 mass% Mn binary alloy

Two-dimensional finite element analysis together with stream function and neural network models are employed to determine thermo-mechanical behavior during hot strip rolling of AA5083. An appropriate velocity field and stream function is first determined using the rule of volume constancy and upper bound theorem and then temperature field within the metal is predicted by means of a two-dimensional conduction–convection model. In order to consider the effect of flow stress and its dependence on temperature, strain and strain rate, a neural network model is also employed in the analysis. Based on the performed tensile tests, two different neural network models are constructed one for smooth yielding and the other one for the serrated flow. Then, the ANN models are coupled with the thermo-mechanical analysis. In the next step, by combination of the predicted temperature, strain and strain rates fields and the experimental data achieved from the tensile tests, the occurence of dynamic strain ageing during hot rolling is predicted. The model predictions are then compared with the experimental data and good agreement is observed between the two sets of results that shows the validity of the proposed model.