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1.
Surface treatment of wood was carried out using acryl-silicon type resin including didecyl dimethyl ammonium tetrafluoroborate (DBF), boron-containing quaternary ammonia compound. Surface-treated wood specimens were exposed laboratory decay resistance tests after completing a 10-cyle severe weathering process. In laboratory decay resistance tests, one brown-rot decay fungus, Fomitopsis palustris and one white-rot decay fungus, Trametes versicolor were used. The specimens were also subjected to laboratory termite resistance tests using subterranean termites, Coptotermes formosanus. Wood specimens treated with 2% DBF and resin containing preservative solution showed improved decay and termite resistance suggesting that the preservative solution at 2% DBF concentration provides lasting protection against wood degradation owing to the amount of DBF remaining in the wood after severe weathering process. However field tests are needed to determine the performance of surface-treated wood with DBF and the acryl-silicon type resin in more realistic conditions.
Oberflächenbehandlung durchgeführt mit Didecy – dimethyl – ammonium – tetrafluorborat (DBF) in Kombination mit Acryl - Silicon - Harz als Schutzmaßnahme gegen biologischen Abbau und Termitenbefall von Holz
Zusammenfassung Oberflächenbehandlung von Holz wurde mit einem Acryl-Silikon Harz einschließlich Didecyl – Dimethyl – Ammonium – Tetrafluorborat (DBF) vorgenommen, eine borhaltige quaternäre Ammonium - Komponente. Oberflächenbehandelte Holzproben wurden nach dem Durchlaufen 10 vollständiger strenger Witterungszyklen im Labor Fäulnisresistenztests unterzogen. Dabei wurden ein Braunfäulepilz Domitopsis palustris und ein Weißfäulepilz, Trametes versicolor benutzt. Mit denselben Proben wurden im Labor auch Termitenresistenzversuchen mit der unterirdischen Termitenart Coptotermes formosanus durchgeführt. Proben, die mit 2% DBF und einem konservierungsmittelhaltigem Harz behandelt waren, zeigten verbesserte Fäulnis- und Termitenresistenz, was nahe legte, dass die Konservierungslösung mit 2%iger DBF - Konzentration dauerhaften Schutz gegen Holzabbau liefert, auf Grund der Menge an DBF, die nach dem strengen Witterungsprozess im Holz verbleibt. Um die Dauerhaftigkeit der Resistenz von Holz, dessen Oberfläche mit DBF und Acryl-Silicon - Harz behandelt wurde, festzustellen, sind allerdings Freilandversuche unter wirklichkeitsnahen Bedingungen erforderlich.
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2.
This study evaluates the decay and termite resistance of wood treated with didecyl dimethyl ammonium tetrafluoroborate (DBF), a recently developed quaternary ammonia compound containing boron. Laboratory decay resistance tests were performed using brown-rot fungus, Fomitopsis palustris and white-rot fungus, Trametes versicolor. Treated wood specimens were also subjected a 3-week-termite resistance test using subterranean termites, Coptotermes formosanus. Decay resistance tests showed that wood specimens treated with 0.5 and 1.0% DBF solutions were well protected against both fungi even after a 10-day severe leaching process, suggesting the adequate fixation of DBF in wood. DBF treatment at 0.1% concentration was efficient against subterranean termites, Coptotermes formosanus Shiraki based on mass losses in both leached and unleached wood specimens. The ability of DBF to inhibit discolorations by selected mold and stain fungi was also screened in laboratory conditions. DBF at the highest concentration level (1%) provided limited protection against mold and staining fungi tested, however, it was effective for only short-term protection (1 or 2 weeks) at lower concentrations. These results suggest that DBF is promising to protect wood to be used outdoors against both fungal decay and termite attack however field tests are needed to observe the performance of DBF-treated wood in ground contact.  相似文献   

3.
This study evaluated the ability of boron-containing quaternary ammonia compound, didecyl dimethyl ammonium tetrafluoroborate (DBF) for inhibition of mold and stain fungi in comparison with another quaternary ammonia compound, didecyl dimethyl ammonium chloride (DDAC) and a commercial boron wood preservative, disodium octoborate tetrahydrate (DOT). The ability of the chemicals to inhibit discolorations by selected mold and stain fungi was screened in laboratory conditions. Both DBF and DDAC at 1% concentration provided protection against the fungi tested, however DOT at all concentrations showed no protection for the entire testing period. On the other hand, DBF and DDAC at lower solution strengths were capable of protecting wood against the fungi for a short term (2 weeks).  相似文献   

4.
Modifications in the structure of wood preserving quaternary ammonium compounds (QACs) may result in improvements in leaching of components and biological resistance of treated wood. In this study, we evaluated the leaching characteristics and termite resistance of wood treated with a newly developed QAC compound didecyldimethylammonium tetrafluoroborate (DBF) in comparison with commercial DDAC, another QAC compound. Laboratory leaching tests showed that amount of DBF released from treated wood specimens was less than that of DDAC. However there was no difference between DBF and DDAC in the resistance of treated wood specimens against termite attack. Retention level at about 3 kg/m3 of DBF and DDAC seems to be enough to protect wood against termite attack, however, no comparative data are available for resistance of DBF and DDAC-treated wood against wood degrading fungi. Field tests are also needed to determine the performance of DBF-treated wood in ground contact in comparison with DDAC.  相似文献   

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The antimicrobial properties of wood extracts are well known; however their application to edible films is limited. In this study, the minimum bactericidal concentration (MBC) of kiam wood extract was established as 300 mg/L at which bacterial growth was completely inhibited. The antimicrobial properties of hydroxypropyl methylcellulose (HPMC) films containing 1-5 fold of MBC of kiam wood extract were tested against Escherichia coli O175:H7, Staphylococcus aureus and Listeria monocytogenes. The edible films containing kiam wood extract exhibited more effective impact on the growth reduction of L. monocytogenes than S. aureus and E. coli (p < 0.05). The use of kiam wood extract at 1 and 2 fold of MBC incorporated into edible HPMC films did not exhibit any antimicrobial activity. However, the inhibitory effect of edible HPMC films containing kiam wood extract was observed at 3, 4 and 5 fold of MBC. The greatest zone of inhibition was observed at 5 fold of MBC incorporated in edible HPMC films. Tensile strength and elongation at break significantly decreased with the incorporation of kiam wood extract, whereas water vapor permeability and film solubility increased. The color of edible films became darker and more reddish-yellowish as well as having a lower transparency as the level of kiam wood extract was increased. Kiam wood extract incorporated in edible film provided the films with a rougher surface than pure edible film. Our results pointed out that the incorporation of kiam wood extract as a natural antibacterial agent has potential for use in extending the shelf life of food products.  相似文献   

9.
首次建立利用高效液相色谱-质谱联用技术检测二硬化牛油烷基二甲基氯化铵(DHTDMAC)的方法。经对比选择了高提取效率的甲醇超声提取法,并优化了超声提取的温度、时间;以氨基柱为分析柱,乙酸/甲醇为流动相,在10 min内完成对二硬化牛油烷基二甲基氯化铵的定性、定量分析,结果表明,本法简便、快速、准确、可靠。  相似文献   

10.
用液氨对棉/羊绒(80/20)织物进行处理后,织物的的拉伸断裂强力比原织物有较大提高,折皱回复角(WRA)获得明显提高;羊绒纤维表面鳞片有一些损伤,单纤强度下降。经复合树脂整理,织物防皱性能可获得进一步改善,文章对其原因作了较为深入的分析。  相似文献   

11.
The electrochemical behavior of 2,3-dihydroxybenzoic acid (2,3-DHBA) and the electron-transfer characteristics between Cu(II) and 2,3-DHBA were studied in aqueous solutions using cyclic voltammetry (CV). The overall electrochemical oxidation process of 2,3-DHBA by Cu(II) may be classified as a chemical reaction involving one-electron oxidation of 2,3-DHBA to its semiquinone radical in solution, followed by an electron-transfer reaction involving the oxidation of the semiquinone radical to a quinone at the electrode surface. In the presence of H2O2, oxidation of 2,3-DHBA by Cu(II) is enhanced due to the regeneration of Cu(II) by H2O2 oxidizing Cu(I). The redox cycling between Cu(I)/Cu(II) and H2O2 also produces hydroxyl radicals (OH). Even though the presence of OH may not be detected at the surface of a glassy carbon electrode, production of electroactive dissolved oxygen (O2) suggests the presence of OH. The production of O2 is dependent on Cu(II):H2O2 concentration ratio. At the electrode surface and when the initial Cu(II):H2O2 is less than 1, O2 is produced, suggesting that H2O2 may act as a scavenger for OH; at initial Cu(II):H2O2 > 1, the production of O2 is not favored, and OH will be involved in the oxidation of Cu(I) and the organic ligand. The reaction mechanisms proposed in this study indicate that OH production by chelator-mediated Fenton reactions is favorable under conditions found in the wood cell wall.  相似文献   

12.
European Journal of Wood and Wood Products - Compatibility between preservative and resin plays an important role in determining the adhesive performance of preservative-treated engineered wood...  相似文献   

13.
目的利用连续流动分析仪建立以水杨酸-次氯酸盐比色法为基础的葡萄酒和葡萄汁中氨氮的分析方法。方法葡萄汁及葡萄酒样品经过滤后直接进样,试样与试剂在蠕动泵的推动下进入化学反应模块,在密闭的管路中连续流动,并按特定的顺序和比例混合、反应,显色完全后进入流动检测池进行光度检测。结果氨氮标准溶液利用12%乙醇溶液配制线性范围为0~60 mg/L,相关系数(r2)大于0.999;方法检出限(LOD)为0.015mg/L。在低、中、高三个浓度水平添加下,样品氨氮回收率范围为90.0%~96.8%,相对标准偏差(n=6)均小于1%。结论该方法灵敏度高,重复性好,操作简便,适用于大批量葡萄酒和葡萄汁中氨氮含量的检测。  相似文献   

14.
The effect of activated charcoal containing wood vinegar liquid (Nekka-Rich) on Cryptosporidium parvum was evaluated in vitro and in vivo. First, the adsorption of C. parvum by the activated charcoal component of Nekka-Rich was examined. When mixed, C. parvum oocysts were effectively adsorbed by activated charcoal. Next, the effect of the wood vinegar liquid component of Nekka-Rich was assessed. Wood vinegar liquid had an antiprotozoan activity against C. parvum oocysts. Finally, the anticryptosporidial effect of Nekka-Rich was evaluated in calves experimentally infected with C. parvum. Six neonatal calves at 7 d of age were orally infected with 1 × 105 oocysts of C. parvum. When diarrhea was observed (on d 3 after the experimental infection), 3 calves received a milk replacer containing 10 g of Nekka-Rich at 8-h intervals for 4 consecutive days, and 3 control calves were given a milk replacer without Nekka-Rich at 8-h intervals for 4 consecutive days. Calves fed milk with Nekka-Rich showed recovery from diarrhea 1 d after the start of treatment. Significantly less fecal excretion of C. parvum oocysts was observed 1 d after treatment in calves fed Nekka-Rich. On d 2 from the beginning of treatment with Nekka-Rich (on d 5 after the experimental infection), oocysts were not isolated from fecal samples. On the other hand, nontreated control calves developed severe diarrhea, and fecal excretion of oocysts was consistently observed. Calves in both groups were killed for collection of samples, which were subjected to scanning electron microscopy. Scanning electron microscopy revealed adherence of C. parvum oocysts to the intestinal epithelial surface of nontreated control calves, whereas a lack of C. parvum adhesion was observed in calves fed Nekka-Rich. These results suggest that Nekka-Rich would be useful for the treatment of cryptosporidiosis in neonatal calves.  相似文献   

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European Journal of Wood and Wood Products - This work deals with the microencapsulation of di-ammonium hydrogen phosphate (DAHP) in polyurethane using an interfacial polymerization method. The...  相似文献   

17.
Microwave radiation was used as the heating source in southern pine wood liquefaction with PEG/glycerin binary solvent. It was found that microwave heating was more efficient than conventional oil bath heating for wood liquefaction. The wood residue content of the H2SO4 catalyzed liquefied wood dropped to zero within 5?min with microwave heating. The resulting liquefied wood polyols have suitable hydroxyl values for the preparation of rigid PU foams. Both the compressive strength and apparent modulus of the liquefied-wood-based PU foams increased as the isocyanate index increased from 80 to 120. The foams from H3PO4 catalyzed polyols had lower densities than those from H2SO4 and the petroleum-based controls. They also showed lower strength and modulus than those from H2SO4. Liquefied-wood-based PU foams generally have lower compressive strength and apparent modulus than the petroleum-based controls. However, they showed better restorability from deformation than the petroleum-based controls.  相似文献   

18.
A defined mixture of 48 bacteria isolated from the chicken caecum and undefined, anaerobic cultures of the contents of the caecum of both chicken and turkey have been compared for their ability to prevent intestinal colonization of newly hatched chicks and turkey poults by Salmonella kedougou or S. typhimurium.Although treatment with undefined cultures from either type of bird confirmed previous observations that reciprocal protection against Salmonella can be obtained, the defined bacterial mixture protected chicks but not poults, even when a further 17 strains of different caecal bacteria were incorporated in the treatment mixture. The undefined culture from chicken was less protective for poults than the corresponding turkey culture.  相似文献   

19.
A simple, rapid and sensitive immunoassay, based on immunomagnetic particles (Dynabeads M-280) was developed for detection and quantitation of Clostridium perfringens type A enterotoxin from faecal and food extracts. The assay had a detection limit of 2.5 ng/ml enterotoxin in homogenates of faeces and inoculated meat extracts. The specificity was confirmed by both crossed immunoelectrophoresis and Western immunoblotting techniques, using a purified enterotoxin as standard.  相似文献   

20.
Adsorption process has an importance for improving the color of juice and also stabilizing the final product during the shelf life. In this study, polyvinylpolypirrolidone (PVPP) and octadecyl acrylate-co-ethylene glycol dimethacrylate (ODA-EGDMA) polymeric resins were used as adsorbents for improving the color properties of apple juice. The ODA-EGDMA resin was prepared by classical suspension polymerization technique and characterized by electron microscopy. The obtained spherical particles diameters were between 20 and 140 μm. PVPP was selected as reference polymeric material for its importance in the juice industry. The adsorption kinetics of dark-colored compounds on adsorbent polymeric resins were studied at different adsorbent resins concentrations (1, 2, 4, and 8 g adsorbent resin per liter of apple juice) at the constant temperature (20 °C) in batch reactor. Langmuir adsorption model was applied for both PVPP and ODA-EGDMA polymeric adsorbents. The Langmuir isotherms were plotted for both polymeric adsorbents by evaluation of the absorbance data of apple juice at 420 nm. Langmuir isotherm's empirical constants known as K ad and Q 0 were calculated from the equilibrium data. Numerical value of K ad and Q 0 were determined as 5.0578 and 0.3089 for the ODA-EGDMA polymeric resin, 2.4824 and 0.5268 for the PVPP adsorbent, respectively. The scope of this study included comparison of reusability and regeneration properties of the each polymeric adsorbent. For this purpose, series of experiment were done in pack bed column application. Pressure drop measured throughout the PVPP pack bed column was 4.8 times higher than ODA-EGDMA pack bed column at same flow rate (2.5 mL/min) during the this group experiment. ODA-EGDMA resin and PVPP were regenerated with NaOH (4% w/v, 50 °C) after each run. After regeneration, average removal of dark color (relative absorbance change at 420 nm) of apple juice was determined as 76.47±0.90% for ODA-EGDMA and 91.51±0.86% for PVPP adsorbent resin.  相似文献   

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