10 resultados para Steinkamp BP7


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The goal of this research was to determine the density distribution in medium density fiberboard (MDF), manufactured with polyurethane derived from castor oil using, ultrasonic wave technique. The equipment used in this test is Steinkamp BP7 with plan and exponential transducers, both with 45 kHz frequencies, located in several zones on the plate in order to determine wave ultrasonic velocity. The Pinus caribaea and Eucalyptus grandis fiberboard were manufactured in the quality control and products development laboratory of Duratex with 500 mm long, 500 mm large, 8 and 15 mm of thickness. Three MDF for each fiber specimen and thickness were fabricated, totalizing twelve plates tested. The MDF were produced with 5% polyurethane addition, in temperature of 160°C, tension press of 53 bars and addition of moisture content of 12%. For determination of fiberboard density, samples were extracted from the same zones where the wave ultrasonic velocity was determined. In this case, DAX-Ray equipment was used. Statistical analysis shows good agreement with wave ultrasonic velocity and the density profile, validating the application of non-destructive technique in order to determine the density profile of MDF's.

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本文以苯并(a)芘为目标污染物,探讨了母体化合物BaP及其次生代谢产物的连续降解的方法、降解过程和微生物的酶蛋白应答,并运用种子(小麦、白菜和萝卜)根伸长生长实验,考查了BaP的不同降解时期次生代谢产物造成的复合污染整体效应,旨在探讨BaP及其次生代谢产物的降解影响因素,减少其环境累积,为BaP污染环境的全面修复提供实验依据和理论基础。 在实验条件下,运用HPLC鉴定出真菌FZSY-1降解BaP的同时生成了三个次生代谢产物BP1,6-quinone, BP7,8-diol 和 3-OHBP;同时鉴定出真菌FZSY-2降解BaP的同时生成了两个代谢产物BP1,6-quinone 和 3-OHBP。 驯化微生物与氧化剂(KMnO4)的耦合降解系统对BaP及其代谢产物的连续降解效果好于单纯微生物降解。三个次生代谢产物中,BP1,6-quinone在环境中最易累积。同时提出了微生物与氧化剂协同的作用可以有效促进环境中持久有机污染物(尤其是高浓度,小面积污染)的连续降解。对于FZSY-1与氧化剂(KMnO4)耦合降解BaP,在TW80存在下,与对照(未加TW80)相比,在降解的前期(3天取样),BaP及其代谢产物的降解相对滞后;而在降解的后期(12天取样),BaP及其代谢产物的降解高于对照。 在不同BaP浓度下,检测了四种酶,C120、C230、CAT和PPO。三株细菌的CAT酶活与BaP的浓度无关;三株细菌的C230酶活都比较高;三株细菌的PPO酶活均较低。加入共代谢底物(琥珀酸钠)后,与对照(未加入共代谢底物)相比,C120、C230酶活明显提高。 以BaP以及FZSY-1(BZSY-2)降解BaP不同时期的复合降解产物(BaP,M6,M12,CK)为目标污染物,它们对小麦种子根伸长的抑制作用顺序为:M6﹥BaP﹥M12﹥CK。BaP,M6,M12,CK对白菜和萝卜种子根伸长的抑制作用顺序和小麦相同;同一目标污染物(M6)对这几种供试种子(小麦、白菜和萝卜)根伸长的抑制作用顺序为小麦﹥白菜﹥萝卜;三种植物种子根伸长抑制作用均表现为:真菌的M6﹥细菌的M6,真菌的M12﹥细菌的M12。

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在以驯化过的芽孢杆菌(BA-07)降解BaP的过程中,鉴定出2个BaP的未开环代谢产物顺式-4,5-二氢-4,5-二醇-BaP(cis-BP4,5-dihydrodiol)和顺式-7,8-二氢-7,8-二醇-BaP(cis-BP7,8-dihydrodiol).由于该产物对微生物有一定毒性,所以难于进一步降解.为提高BaP降解的同时,降低cis-BP4,5-dihydrodiol和cis-BP7,8-dihydrodiol的累积,对2种降解方法(即单纯用BA07降解和运用高锰酸钾与BA-07耦合的方法降解)进行了比较,并且优化了连续降解的参数.结果表明,①对BaP及其代谢产物的连续降解,化学氧化与微生物耦合(高锰酸钾与BA-07)的降解效果明显好于单纯利用微生物(细菌BA-07)的降解;②在同一时间取样,cis-BP4,5-dihydrodiol的残留率均高于cis-BP7,8-dihydrodiol;③当BaP的浓度为40μg/mL,培养基的最佳pH为7.0,以琥珀酸钠为共代谢底物,可以显著提高BaP降解率,降低cis-BP 4,5-dihydrodiol和cis-BP7,8-dihydrodiol的累积.同时提出了化学氧化与微生物协同的方法可以有效促进环境中持久有机污染物的连续降解.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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rnNitric oxide (NO) is important for several chemical processes in the atmosphere. Together with nitrogen dioxide (NO2 ) it is better known as nitrogen oxide (NOx ). NOx is crucial for the production and destruction of ozone. In several reactions it catalyzes the oxidation of methane and volatile organic compounds (VOCs) and in this context it is involved in the cycling of the hydroxyl radical (OH). OH is a reactive radical, capable of oxidizing most organic species. Therefore, OH is also called the “detergent” of the atmosphere. Nitric oxide originates from several sources: fossil fuel combustion, biomass burning, lightning and soils. Fossil fuel combustion is the largest source. The others are, depending on the reviewed literature, generally comparable to each other. The individual sources show a different temporal and spatial pattern in their magnitude of emission. Fossil fuel combustion is important in densely populated places, where NO from other sources is less important. In contrast NO emissions from soils (hereafter SNOx) or biomass burning are the dominant source of NOx in remote regions.rnBy applying an atmospheric chemistry global climate model (AC-GCM) I demonstrate that SNOx is responsible for a significant part of NOx in the atmosphere. Furthermore, it increases the O3 and OH mixing ratio substantially, leading to a ∼10% increase in the oxidizing efficiency of the atmosphere. Interestingly, through reduced O3 and OH mixing ratios in simulations without SNOx, the lifetime of NOx increases in regions with other dominating sources of NOx

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This paper is a report about the FuXML project carried out at the FernUniversität Hagen. FuXML is a Learning Content Management System (LCMS) aimed at providing a practical and efficient solution for the issues attributed to authoring, maintenance, production and distribution of online and offline distance learning material. The paper presents the environment for which the system was conceived and describes the technical realisation. We discuss the reasons for specific implementation decisions and also address the integration of the system within the organisational and technical infrastructure of the university.

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Good results evaluating material properties using non-destructive testing (NDT) techniques have been achieved for decades. Several studies to understand the influence of temperature and moisture content on NDT have concluded different effects. In this study, NDT parameters were measured on the principal structural Spanish sawn timber species, Scots pine (Pinus sylvestris L.). NDT were conducted on 216 specimens of nominal dimensions 20 by 20 by 400 mm. Specimens were divided into several groups and studied at six different temperatures and four different moisture contents. Commercial equipment and techniques applied were Sylvatest Duo (ultrasonic wave technique), Steinkamp BPV (ultrasonic wave technique), and Grindo Sonic Mk5 "Industrial" (vibration analysis technique). Differences in NDT values within specimens at different temperatures and moisture contents were obtained. Main results of this study and relationships that describe changes in NDT values by effect of temperature and moisture content are presented.

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The reconstituted pea chloroplastic outer envelope protein of 16 kDa (OEP16) forms a slightly cation-selective, high-conductance channel with a conductance of Λ = 1,2 nS (in 1 M KCl). The open probability of OEP16 channel is highest at 0 mV (Popen = 0.8), decreasing exponentially with higher potentials. Transport studies using reconstituted recombinant OEP16 protein show that the OEP16 channel is selective for amino acids but excludes triosephosphates or uncharged sugars. Crosslinking indicates that OEP16 forms a homodimer in the membrane. According to its primary sequence and predicted secondary structure, OEP16 shows neither sequence nor structural homologies to classical porins. The results indicate that the intermembrane space between the two envelope membranes might not be as freely accessible as previously thought.