Effect of fixation time on leaching of copper-ethanolamine based wood preservatives

Zusammenfassung Fixation in copper-ethanolamine treated Norway spruce wood is finished in the first or in the second week after impregnation depending on the concentration of wood preservatives used. However, copper losses increased after four weeks of fixation again, presumably due to lignin depolymerisation caused by ethanolamine.      

Effect of fixation time on leaching of copper-ethanolamine based wood preservatives

Fixation in copper-ethanolamine treated Norway spruce wood is finished in the first or in the second week after impregnation depending on the concentration of wood preservatives used. However, copper losses increased after four weeks of fixation again, presumably due to lignin depolymerisation caused by ethanolamine.     

Improvement of fungicidal properties and copper fixation of copper-ethanolamine wood preservatives using octanoic acid and boron compounds

Copper ethanolamine preservatives are one of the most important solutions for wood preservation. As copper itself can not ensure sufficient protection against wood destroying organisms we combine it with other co-biocides like quaternary ammonium compounds, azoles and/or boron. Influence of different boron compounds and octanoic acid on copper fixation as well as performance of spruce wood impregnated with different copper/ethanolamine/boron based aqueous solutions is described in this paper. Copper fixation was determined according to the modified ENV 1250 (1994) standard method, while performance against Antrodia vaillantii, Gloeophyllum trabeum and Trametes versicolor was tested according to the mini block procedure. The results showed that addition of boron increases copper leaching, but on the contrary improves performance against wood decay fungi. On the other hand, addition of octanoic acid improves copper fixation, and slightly decreases resistance against copper tolerant fungi.     

Resistance based moisture content measurements on native,modified and preservative treated wood

Resistance characteristics were determined for a total of 27 wood-based materials containing native soft- and hardwoods, differently modified timbers and preservative treated timbers. A functional relation between measured electrical resistance and gravimetrical wood moisture content (MC) was established in a range between 15 and 50 % MC. Most precise MC estimation was found for salt-treated timber (±2.5 %), followed by native timber (±3.5 %) and modified timber (±7 %) in the hygroscopic range. As expected, preciseness decreased above fiber saturation, but was still sufficient for native timber (±8 %) and preservative treated wood (±5 %) at approx. 50 % MC.     

Protein impact on the capability of the protein-borate preservative penetration and distribution into pine and aspen wood

The aim of the research project was to determine the capability of the protein-borate preservative to penetrate into the wood of Scots pine (Pinus sylvestris L.) and aspen poplar (Populus tremula L.). This capability was assessed by the preservative retention and the measurement of the penetration depth of the treatment solution. The scope of the performed experiments comprised two methods of treatment. The treatability of the two wood species with the examined formulations was compared with their treatability with the solution of the boric acid alone or with protein. The performed quantitative analysis of the boric acid and protein in individual wood layers allowed to characterise the distribution of the formulation ingredients on the cross-section of the treated elements. Significant differences were shown to occur in the degree of wood treatment with the formulation containing globular protein using the vacuum and vacuum-pressure methods. In addition, the impact of the protein presence on the way of boric acid penetration into wood was also determined.     

食品防腐剂的发展趋势及天然食品防腐剂——R-多糖（克霉王）简介

介绍了食品防腐剂的发展历史、现状和趋势。简要介绍了R-多糖的研发历程、特点及应用中的注意事项。     

采收成熟度和时间菜豆采后贮藏品质的影响

以贵阳青棒豆为试材,研究了不同采收成熟度和时间采收菜豆贮藏期间主要理化指标变化规律的影响。研究显示:不同采收成熟度和时间对菜豆采后保鲜效果影响显著,其中,六成熟时采摘豆荚期间品质变化较缓和,贮藏24 d营养成分损失较小,豆荚纤维化、黄化不明显,消费者易接受;5月中旬采收菜豆的贮藏品质显著高于其他几个采收期,有利于贮运。因此,贵阳青棒豆大棚栽培以4⁵月份气候条件最佳,六成熟时采摘。     

The penetration characteristics of CCA preservatives in wood-radial/tangential,processes and species effects

The penetration profiles of CCA preservatives and of Cu, Cr, and As in sawn timber in the radial and tangential directions are described. Interesting differences in the penetration in these two directions can be observed. Variations of the penetration profiles are also noticed according to the impregnation process used. Similar profiles for industrially-treated pine and eucalyptus poles show marked differences in behaviour between pine and eucalyptus. The unusual trends shown by eucalyptus are quantified and their cause explained in term of the physico-chemical characteristics of the system.     

Effect of simulated rainfall and weathering on release of preservative elements from CCA treated wood

The release of arsenic from wood pressure-treated with chromated copper arsenate (CCA) can be decreased by application of wood finishes, but little is known about the types of finishes that are best suited for this purpose. This study evaluated the effects of finish water repellent content and ultraviolet (UV) radiation on the release of arsenic, copper, and chromium from CCA-treated wood exposed to simulated rainfall. Deck boards treated with CCA were either left unfinished or dipped in a finish prepared with 1%, 3%, or 5% water repellent. All specimens were exposed to leaching from simulated rainfall, and a subset of specimens was also exposed to UV radiation. The rainfall was collected and analyzed for total elemental arsenic, copper, and chromium. The water repellent significantly decreased the amounts of these elements in the runoff, but for the short duration of this study there was no difference among the three water repellent concentrations. It is possible that water repellent content would have a greater effect over a longer exposure period. Exposure to UV radiation caused a significant increase in leaching from both finished and unfinished specimens. This effect may be a result of increased surface area during weathering as well as loss of fibers caused by UV-induced surface erosion.     

Evaluation of particulate zinc and copper as wood preservatives for termite control

Subterranean termites are a major factor in the biodegradation of wood construction products. In this study the efficacy of wood treated with micronized copper, zinc oxide and their mixture was compared to that of wood treated with soluble amine copper oxide against subterranean termites in a laboratory test. All of the formulations tested were effective in controlling wood degradation by the termites, with copper being slightly more effective than zinc and micronized copper being slightly more effective than amine copper.     

Effect of excessive pretreatment of pine timber with CCA wood preservatives on the bond quality of PRF and TRF wood adhesives

The phenol-resorcinol-formaldehyde adhesive is suitable for use at all levels of CCA retention that were tested. Due to changes in retention during treatment, best results are obtained if the glue-spread rate is kept above the standard of 200 g/m², or control measures are taken to prevent the glue-spread from dropping below this level. The tannin-resorcinol-formaldehyde adhesive, without modification, unlike its performance in the manufacture of plywood, appears from these tests to be less suitable for use on treated timber from the view point of lowered percentage of wood failure.     

Impact of surface water conditions on preservative leaching and aquatic toxicity from treated wood products

New alternative wood preservatives contain higher levels of copper (Cu) which can promote aquatic toxicity in natural water systems. Earlier work focused on evaluating toxicity using laboratory generated leaching solutions. In this study, the impact on preservative leaching and aquatic toxicity from treated wood products was evaluated using natural surface waters including waters from two rivers, three lakes, two wetlands, and one seawater, in addition to synthetic moderate hard water and deionized water. Blocks of wood treated with Cu based alternatives such as alkaline copper quaternary (ACQ) and copper boron azole (CBA), along with chromated copper arsenate (CCA)-treated wood, were leached under quiescent conditions, and total Cu, labile Cu, and heavy metal toxicity were measured. Results show that ACQ- and CBA-treated wood leach approximately 10 and 20 times more total Cu relative to CCA-treated wood and that the presence of organic and inorganic ligands in natural waters lowered the labile fraction of Cu relative to that from laboratory generated leaching solutions. Aquatic toxicity was found to correlate with the labile Cu fraction, and hence, the aquatic toxicity of the treated wood leachates was lower in natural waters in comparison to laboratory leaching solutions. The results of the present study suggest that studies designed to evaluate the impacts of treated wood should therefore consider the role of complexation in reducing the labile Cu fraction and its potential role in decreasing toxicity.     

普鲁兰多糖/槐糖脂抑菌保鲜膜的制备

目的:为替代传统不可再生塑料保鲜膜,采用经济环保原料制作性能优良的抑菌保鲜膜,并确定其最佳配方。方法:在最佳成膜条件下,采用单因素实验分析普鲁兰多糖、槐糖脂和甘油浓度对成膜性能的影响,并考察了槐糖脂的抑菌浓度。在此基础上设计正交实验,确定抗菌保鲜膜原料的最佳配比,并验证膜液及保鲜膜的保鲜性能。结果:槐糖脂对金黄色葡萄球菌抑制效果显著(p<0.01),2.4 g/L时达到100%抑制;对大肠杆菌和白色假丝酵母菌菌有不同程度的抑制作用,4.0 g/L时抑菌率分别为28.75%和14.53%。确定了膜液的最佳配方为普鲁兰多糖18 g/L、槐糖脂3.6 g/L、甘油8.75 g/L。该膜液及所成的抗菌保鲜膜对樱桃的保鲜效果与对照组相比效果显著(p<0.01)。结论:将槐糖脂生物表面活性剂作为可抗菌保鲜膜的原料,为绿色抗菌保鲜膜的制备工艺提供新的理论依据。     

Effect of ponding,steaming and drill perforation on preservative treatment of fir wood (Abies cephallonica L.) with CCB

Wood from fir (Abies cephallonica L.) in round form (length 1.20 m, diameter 14–20 cm) and in the form of beams (length 1.25 m, 5 cm×7 cm in cross section) were impregnated with 2% CCB by the full cell process after or without a pre-treatment of ponding, steaming or drill perforation. Each pre-treatment caused a significant increase of the dry salt retention and the impregnated area in fir logs and sapwood beams. Drill perforation was the most effective pre-treatment causing full impregnation of sapwood beams. Between ponding and steaming the differences were relatively small but uniform penetration was achieved only in round wood after ponding. The significantly increased penetrability, caused by the three pre-treatments under the described specific conditions, widens the uses of fir wood but it doesn’t meet the requirements of retention for the most difficult conditions in service.     

复配保鲜剂对冻藏鱿鱼品质变化的影响

选取海藻糖、乳酸钠、混合磷酸盐进行复配,以持水率(WHC)、盐溶性蛋白质含量(SSP)、活性巯基含量为指标,研究鱿鱼在-20℃冻藏条件下的品质变化,通过3因素3水平的L9(34)正交试验筛选出保鲜效果最好的复配保鲜剂,并结合色差试验和质构分析,对保鲜剂的保鲜效果进行验证。结果显示:各保鲜剂对冻藏鱿鱼保鲜效果影响的主次顺序为海藻糖乳酸钠混合磷酸盐,海藻糖和乳酸钠的添加量对试验结果有极显著影响(P0.01),混合磷酸盐的添加量对试验结果有显著影响(P0.05)。复配保鲜剂的最佳配比浓度是海藻糖添加量5%,乳酸钠6%,混合磷酸盐0.5%。在-20℃冻藏60 d后,复配组的WHC、SSP、活性巯基含量分别为87.76%、28.86 mg/g、5.16×10-5mol/g,和空白组相比差异显著(P0.05)。验证结果表明,复配保鲜剂对-20℃贮藏条件下的鱿鱼保鲜效果显著。     

提高质量 争创名牌 努力满足卷烟工业对烟叶的需求

根据国家烟草专卖局提出的“十五”烟叶科技发展计划，阐述了名优特烟叶的含义，名优特烟叶形成的原因，开发的指导思想，前景意义以及开发重点和应采取的措施等，为名优特烟叶的开发提出了基本思路。     

土壤对铵、钾及磷酸离子吸附固定的研究

综述了土壤对铵、钾及磷酸离子的吸附固定情况,阐明了土壤对3种元素的固定量,分析了影响土壤对3种元素固定的因素及其各自的释放特点。