Peelable seam systems and their production

In packaging, heat-seal seams have been known as ‘peelable seals’ for a long time. In this system seal medium A is sealed with seal medium B. They are combined in such a way that the sealed seam can be reopened by a defined force without destroying the packaging. Typical applications for peelable seals are boxes or containers with sealed cover sheets, blisters and flexible packagings. The tendency towards peelable packagings has increased recently. This research project dealt with the relevant processes and parameters that influence peelable seals and aims to define reproducible, peelable sealed seams and to elaborate upon a method to develop and produce peelable seam systems. Compared with other research programmes or bibliographical data, this project dealt, in particular, with:

• i the definition of a ‘reproducible, peelable sealed seam’;
• ii an analysis of peelable seam production using the different sealing techniques (heat-contact, ultrasonic and inductive high-frequency);
• iii the influence of the type of sealer jaw on the production and characteristics of peelable seams.

     

Was kann die Wirtschaftsinformatik dazu beitragen,E-Health voran zu bringen?

Ohne Zusammenfassung

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德国施肥法的特点和对我国的启示

德国的施肥法将其肥料的施用依法规范。其主要特点是尽可能地提高肥料养分利用率和最大限度地避免因养分流失而造成的环境污染。中国当前过量施用肥料和低利用率而造成对环境污染日趋严重,应参考德国以立法来规范肥料施用的先进概念和管理办法,根据目前中国农业技术水平尽快推行施肥法规。     

欧洲综合处理畜禽粪尿的工艺技术

欧洲工业化养殖业的成功发展,使每年产生大量的畜禽粪便。近年来,许多欧洲国家政府积极资助对农场废物处理技术的研究开发,以达到保护环境、变废物为有利资源的目的。综合处理畜禽废物的生产工艺技术在欧洲已经逐渐流行起来,其特点是结合多种处理技术,主要适合于畜禽废物已引起严重污染的高密度养殖业地区。本文对欧洲具有一定代表性的综合处理畜禽废物工艺过程进行分析,以便我们了解欧洲综合处理畜禽废物工艺技术的特点、现状和发展趋势。     

Structure–property relation in varieties of silk fibers

Crystallite shape ellipsoid in different varieties of silk fibers namely (i) Chinese (ii) Indian, and (iii) Japanese, has been computed using wide‐angle X‐ray data and Hosemann's one‐dimensional paracrystalline model. The estimated microcrystalline parameters are correlated with the observed physical property of the silk fibers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1979–1985, 2001     

Kinetic assessment and modeling of an ozonation step for full-scale municipal wastewater treatment: Micropollutant oxidation, by-product formation and disinfection

The kinetics of oxidation and disinfection processes during ozonation in a full-scale reactor treating secondary wastewater effluent were investigated for seven ozone doses ranging from 0.21 to 1.24 g O₃ g⁻¹ dissolved organic carbon (DOC). Substances reacting fast with ozone, such as diclofenac or carbamazepine (kP,O₃ > 10⁴ M⁻¹ s⁻¹), were eliminated within the gas bubble column, except for the lowest ozone dose of 0.21 g O₃ g⁻¹ DOC. For this low dose, this could be attributed to short-circuiting within the reactor. Substances with lower ozone reactivity (kP,O₃ < 10⁴ M⁻¹ s⁻¹) were only fully eliminated for higher ozone doses.The predictions of micropollutant oxidation based on coupling reactor hydraulics with ozone chemistry and reaction kinetics were up to a factor of 2.5 higher than full-scale measurements. Monte Carlo simulations showed that the observed differences were higher than model uncertainties. The overestimation of micropollutant oxidation was attributed to a protection of micropollutants from ozone attack by the interaction with aquatic colloids. Laboratory-scale batch experiments using wastewater from the same full-scale treatment plant could predict the oxidation of slowly-reacting micropollutants on the full-scale level within a factor of 1.5. The Rct value, the experimentally determined ratio of the concentrations of hydroxyl radicals and ozone, was identified as a major contribution to this difference.An increase in the formation of bromate, a potential human carcinogen, was observed with increasing ozone doses. The final concentration for the highest ozone dose of 1.24 g O₃ g⁻¹ DOC was 7.5 μg L⁻¹, which is below the drinking water standard of 10 μg L⁻¹. N-Nitrosodimethylamine (NDMA) formation of up to 15 ng L⁻¹ was observed in the first compartment of the reactor, followed by a slight elimination during sand filtration. Assimilable organic carbon (AOC) increased up to 740 μg AOC L⁻¹, with no clear trend when correlated to the ozone dose, and decreased by up to 50% during post-sand filtration. The disinfection capacity of the ozone reactor was assessed to be 1-4.5 log units in terms of total cell counts (TCC) and 0.5 to 2.5 log units for Escherichia coli (E. coli). Regrowth of up to 2.5 log units during sand filtration was observed for TCC while no regrowth occurred for E. coli. E. coli inactivation could not be accurately predicted by the model approach, most likely due to shielding of E. coli by flocs.     

Charging of one or several cylindrical particles by monopolar ions in electric fields

In many electrostatic processes (precipitation of dust, separation of granular mixtures, spraying of powders) insulating particles are subjected to unipolar charging in the presence of other bodies. The present paper addresses this problem from both a computational and an experimental point of view, with the aim to extend an original numerical method of unipolar charge computation to the case of two or more particles, relatively close to each other. The charge acquired by cylinders of various dielectric constants was evaluated with a computer program based on the boundary element method of field analysis. The experimental setup simulated the charging conditions of millimeter-size calibrated cylinders of polyvinyl chloride in a roll-type electrostatic separator, the unipolar space charge being generated by a wire-type electrode. The experimental results, which were in good agreement with the theoretical predictions, put forward that the relative spacing between the particles changes the value of the saturation charge, an effect, which is stronger for particles of higher dielectric constant. These facts should be taken into account in the design of any electrostatic technology based on the corona charging of granular matter.     

Analysis of megadalton ions using cryodetection MALDI time-of-flight mass spectrometry

Presented are initial results from the first commercially available matrix-assisted laser desorption/ionization time-of-flight mass spectrometer specifically designed for the sensitive detection of very high mass ions (macromizer, Comet AG). This new instrument utilizes a 16-element superconducting tunnel junction detector coupled with a fully adjustable gimbal-mounted ion source/focusing region that allows unparalleled sensitivity for detection of singly charged high molecular weight ions. Using this new technology, the singly charged ions in the megadalton region are detected from immunoglobulin M and von Willebrand factor proteins. This detector technology also measures the kinetic energy of the particles impacting the detector, which can be correlated to the charge of the particles. Immunoglobulin G and streptavidin were used to demonstrate the ability of the macromizer instrument to detect high-mass ions and to discern the charge state of the ions.     

Processing Routes to Macroporous Ceramics: A Review

Macroporous ceramics with pore sizes from 400 nm to 4 mm and porosity within the range 20%–97% have been produced for a number of well-established and emerging applications, such as molten metal filtration, catalysis, refractory insulation, and hot gas filtration. These applications take advantage of the unique properties achieved through the incorporation of macropores into solid ceramics. In this article, we review the main processing routes that can be used for the fabrication of macroporous ceramics with tailored microstructure and chemical composition. Emphasis is given to versatile and simple approaches that allow one to control the microstructural features that ultimately determine the properties of the macroporous material. Replica, sacrificial template, and direct foaming techniques are described and compared in terms of microstructures and mechanical properties that can be achieved. Finally, directions to future investigations on the processing of macroporous ceramics are proposed.