提高小管气焊焊接接头机械性能的探讨

目前一些重要小管焊接已采用钨极氩弧焊，但因气焊设备简单，操作方便，在中小企业仍普遍采用，然而，气焊因热量分散，工件受热面积大，热影响区较宽等缺点，影响了接头的安全可靠性，本文将就如何提高接头质量进行探讨。     

输油管路单面焊双面成形焊接工艺研究与应用

对轴油管线单面焊接双面成形焊接工艺进行研究和应用，介绍了焊接操作方法及工艺设备，确定了输油管线焊接工艺参数。     

国内首台623℃超超临界锅炉HR3C与Super 304H异种钢对接的焊接工艺实践研究

文章主要结合田集电厂二期工程实际，针对Super 304H与HR3C对接选用Thermanit 617和YT-HR3C两种焊丝的焊接工艺评定试验结果，从施工工艺和操作难度上进行比较，确定最适合施工安装操作的工艺，并结合工程实际应用中出现的问题总结归纳了相应的质量控制要点。     

爆炸焊接法

本文扼要地分析了爆炸焊接的基本原理和一般工艺方法。并对复合材料的界面过程和焊接质量检验作了阐述。     

采用合成运动实现空间焊接轨迹

本文运用曲线逼近理论，以自行车前叉杆为例对自动焊接机中的焊缝轨迹作了详细的分析，从而提出了采用合成运动来实现空间焊缝轨迹，并用优化理论分析了其误差，可作为简化此类自动焊接机的设计的理论依据。     

压力容器安装焊接质量控制措施探讨

压力容器在工业生产中应用的比较广泛，为了保证压力容器的安全运行，在安装焊接的过程中，要高度重视焊接质量。近年来，焊接工艺取得了一定的发展，尤其是在压力容器的焊接方面，对工业生产作出了极大的贡献。焊接质量的好坏直接影响到压力容器的安全稳定运行，所以要严格控制焊接质量。文章对于压力容器在安装焊接中质量控制的相关问题进行了分析，为焊接质量的控制创造有利的条件。     

浅析电建焊接质量控制

在电建施工中,设备的安装质量很大程度依赖于其焊接质量。焊接作为一项重要的安装工艺,直接关系到工程质量、建设速度以及投产后的运行安全。文章主要阐述了在焊接施工中常见焊接缺陷,对其产生的原因进行深入分析,并提出了避免焊接缺陷以及提高焊接质量的新方法,对指导焊接施工和促进电建焊接技术的发展有一定的参考价值。     

激光焊接锯片过渡层配方的选择与研究

从激光捍接锯片的工艺特点出发，探讨了影响过渡层配方选择的有关因素，结合激光捍接锯片生产实践，研制出几种在生产上行之有效的过渡层配方，促进了我国激光捍接锯片技术的发展。     

船舶焊接特点及要求分析

从船舶焊接的特点入手,对船舶焊接过程中需要注意的事项进行了分析,提出了船舶焊接的具体要求,所得结果对提高船舶焊接质量和效率具有一定的指导意义。     

甘蔗机架疲劳裂纹的磁粉检测及其补焊修复工艺

分析了甘蔗糖厂压榨机架常发生疲劳裂纹部位与应力集中点的相应关系，并根据裂纹部位确定是否适用磁粉检测。同时提出了焊接修复机架的工艺参数，通过实践验证，工艺可靠。     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Food-borne Listeria monocytogenes risk assessment

Listeria monocytogenes is ubiquitous in the environment and in food processing plants. Consequently, foods are frequently contaminated. However, the occurrence rate of listeriosis is only about five cases per million people per year. Listeriosis primarily strikes immunocompromised individuals, pregnant women and the elderly with a fatality rate of 20-25%. The FDA is in the process of finishing a risk assessment that is being conducted as an initial step in reviewing its approach to maximizing the public protection from foodborne L. monocytogenes . The risk assessment evaluated the presence and quantitative levels of L. monocytogenes in 21 groups of ready-to-eat foods. The potential growth of L. monocytogenes between retail point-of-sale, where contamination data originated, and consumption was modelled. The frequency and amount of consumption of these foods completed the data for the exposure assessment. For the hazard characterization or dose response part of the risk assessment, data from animal studies, virulence assays and epidemiological investigations were used to estimate the likelihood of illness for different human groups from consuming different numbers of L. monocytogenes . This risk assessment is a virtual review of current scientific knowledge. Quantitative modelling provides greater insight than a qualitative review and also indicates the uncertainty about our knowledge. The risk assessment does not attempt to define an acceptable or tolerable level of L. monocytogenes consumption or propose changes in regulations. These decisions are the responsibility of risk managers who consider additional factors such as food preferences, technical feasibility and societal values when evaluating regulatory policies.     

Nationaler Rückstandskontrollplan – Stärkung des Verbraucherschutzes durch gezielte Kontrollen bei tierischen Lebensmitteln

Zusammenfassung. Der Nationale Rückstandskontrollplan ist ein seit 1989 von Bund und L?ndern durchgeführtes Programm zur überwachung von Lebensmitteln tierischer Herkunft in verschiedenen Produktionsstufen auf Rückst?nde von gesundheitlich unerwünschten Stoffen. Koordinierende Stelle ist seit dem 01. 11. 2002 das Bundesamt für Verbraucherschutz und Lebensmittelsicherheit. Das Programm wird in der Europ?ischen Union nach einheitlich festgelegten Ma?st?ben durchgeführt. In Deutschland werden j?hrlich ca. 45.000 Tiere oder tierische Erzeugnisse auf verschiedene Stoffe und Stoffgruppen analysiert. Der Plan enth?lt für jedes Bundesland konkrete Vorgaben über die Anzahl der zu testenden Tiere bzw. tierischen Erzeugnisse, die relevanten Stoffe, die anzuwendende Methodik und die Probenahme. Die Probenahme erfolgt zielorientiert. Der Rückstandskontrollplan ist nicht auf die Erzielung statistisch repr?sentativer Daten ausgerichtet. Dargestellt werden Ziele, Organisation und Durchführung des Planes sowie einige Ergebnisse aus den letzten zehn Jahren.      

Innovation in Linen Manufacture

This monograph traces the various means by which flax fibre is transformed into linen yarns and fabrics. The principal innovations and developments of the past fifty years are identified. An extensive range of relevant literature is reviewed. Details are given of how the fibre is extracted from the stem of the flax plant and of the stages of yarn and fabric production. An explanation is given of how yarns are produced from short fibres (known as tow) using carding, drafting and dry spinning, and from long fibres (known as line) using hackling, drafting, doubling, roving and wet spinning in warm water. Further areas covered include yarn winding, linen weaving, dyeing and finishing. New applications for flax fibre, beyond traditional uses in apparel or furnishing fabrics, are also identified.     

STANDARD SIZING AND FIT TESTING APPLIED TO WOMEN'S HOSIERY

The monograph deals with a critical review of the recent research work and development on ramie, a long vegetable bast fibre. The review is divided into two parts. Part I discusses the progress of recent work on ramie, chemical components like fibre degumming, its effects on fibre composition, chemical constituents, i.e. hemicellulose, cellulose, non-cellulosic and mineral matters. Besides various chemical properties of native and modified fibres such as accessibility, infrared, cellulose I–V, DP, grafting, cross linking and resin finishing and dyeing etc. are dealt with.     

Biological activities of oligoketide pigments of Monascus purpureus

Rubropunctatin (1) , monascorubrin (2) , monascin (3) and ankaflavin (4) were purified from the mycelium of Monascus purpureus by flash chromatography on silica gel or reversed phase. Their embryotoxicity towards chicken embryos decreased in the order 2> 1> 3> 4 . The lower homologues 1 and 3 exhibited teratogenic effects on these organisms. Significant antibiotic activities against Bacillus subtilis and Candida pseudotropicalis were found with compounds 1 and 2 . Immunosuppressive activity on mouse T-splenocytes was most pronounced with compounds 3 and 4 . None of the compounds showed significant cytotoxic activity towards rat hepatocytes in vitro . Incubation of resting cells of M. purpureus with glycine afforded the dark-red compounds 5 and 6 where the pyran moiety of 1 and 2 changed into the N-substituted dihydropyridine moiety by replacement of the O-atom by the amino group of glycine. Compounds 5 and 6 were less biologically active than the major pigments 1 - 4 .     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Die e-ventus Technologie – eine Innovation zur nachhaltigen Reduktion von Pflanzenschutzmitteln mit Empfehlung für Bio-Saatgut

Zusammenfassung:  Der intensive Pflanzenbau erfordert wirksame Pflanzenschutzma?nahmen. Eine der wirksamsten Ma?nahmen ist die Behandlung des Saatgutes gegen Pathogene. Sie erfolgt bisher fast ausschlie?lich durch chemische Beizmittel (Pestizide), die Anwender und Umwelt gef?hrden k?nnen. Neue Gesetze und Richtlinien in Deutschland und der Europ?ischen Union fordern die nachhaltige Einschr?nkung der Anwendung chemischer Pflanzenschutzmittel und den Ersatz durch neue, alternative Verfahren und Methoden. Als bereits praxisreifes Verfahren wird die e-ventus Technologie beschrieben. Neue Ergebnisse aus der Forschung, langj?hrige Feldversuche und Produktionserfahrungen best?tigen die Eignung dieser Technologie für den breiten Einsatz in der Landwirtschaft. Neben dem konventionellen Landbau wird die Eignung und Zulassung auch für den Bio-Landbau aufgezeigt. Eingegangen: 15. Januar 2009; angenommen: 10. Februar 2009