Friction welding of wood is an active field of research and would seem to be a potential joining technology in wood industries in the near future. Despite numerous scientific publications in this field, automated industrial applications of this technique are not common up to now. In this paper, we developed an automated welding process that can be easily implemented in industry. The use of beech wood samples is motivated because (i) this species is abundant in the forest resource, (ii) the anatomical structure is homogeneous and therefore highly suitable for the welding process and (iii) the average wood density is high. For the welding process, a sequential control was developed and four different welding modes were applied. We tested four welding modes with a constant rotation speed of the drilling machine (1800 t.mn). During the dowel insertion, the linear displacement was tested for two different constant speeds and for two varying speeds. The results of the pull-out strength test show that the forces during the welding process as well as the strength of the joints produced differ depending on the welding mode. Based on the results it can be recommended that a two-step welding process is applied for wood welding. With the two steps, the forces at the welding machine are kept low and the quality of the joint is high. The sequential control developed can be applied and adapted for different industrial applications. These findings should convince industrial decision-makers of the applicability of this process for daily production.

100% natural tannin-based rigid foams were synthesized. Tannin-furfuryl alcohol networks were polymerized in an acid environment applying a temperature between 120° and 160°C. The process was developed in two ways: in a ventilated oven and in between the heated plates of a press. The foams produced showed a high homogeneity in both cases. By modifying the formulation in terms of type and amount of components it was possible to produce two kinds of foams: (1) light with density of approximately 50 Kg/m³, and (2) resistant having a density of approximately 180 Kg/m³. The compression resistance and the water absorption of these materials were evaluated. The results of these tests, in comparison with those of formaldehyde-reinforced tannin foams, indicated that these lightweight foams have lower mechanical strength but higher water affinity. The latter was also demonstrated with moisture uptake measurements. Particular attention was dedicated to the press-produced foams for their possible application as core-layer for lightweight composite panels.

This paper deals with the potentials of thermally treated beech wood as raw material for making toys. Natural beech wood is a common toy material and the properties of treated and untreated wood are compared. Samples to analyse press fits and joints between moving components were developed and tested under varying climatic conditions. Furthermore samples to analyse the dimensional stability of wooden components were developed and observed under varying levels of humidity and room temperature. The results show that thermally modified beech wood is a promising material for the manufacture of wooden toys. It is assumed that this raw material will be used in toy industries in the future, and furthermore the design of wooden toys will be influenced as it can be proven that this raw material can be employed in diverse developments in relation to the design of functional toys.

In this paper, conventional lightweight paper panels and paper tubes are analysed with respect to their suitability as furniture materials. In order to meet the growing demand of furniture industries to build light furniture, these two materials were tested and found to be suitable for creating very light constructions. Furthermore, increasing consumer demand to include sustainable materials in furniture-making is met by these two products. Joints between the two materials were developed and evaluated. It could be determined that specific adaptations are necessary in order to use paper materials for building furniture. The results of this study are a useful basis for developing construction principles between similar materials with other dimensions, e.g., for architecture.

Scenario-based testing, manual as automatic, is applicable for black-box and specific white-box testing for communication proto- cols and distributed systems. UML models provide scenario descrip- tions by sequence diagrams respectively MSCs. Thus, the combination of TTCN-3, as test description language, and UML by MSC to specify and automatically generate test cases has to be considered. The work in this paper describes a translation of MSC elements to TTCN-3 statements in order to use MSC to define test cases and test case execution order in TTCN-3.

in spray-formed preforms, porosity is unavoidable. This is because the atomising gas becomes entrapped during the process. Normally, nitrogen is used for atomisation and therefore the voids are filled with this gas, which is not soluble in copper. To obtain a dense material after further fortning processes such as extrusion, forging or drawing, porosity has to be limited to a specified level. There are means to influence porosity inside the spray-formed billet. To a certain extent, porosity can be influenced by process parameters. Reactive elements inside the alloy have an additional effect, that is reaction of elements such as Zr, Ti, Al with the entrapped nitrogen. Until now, a detailed explanation has not been given, however, a theory of hot porosity formation is presented in this paper. The calculated content of nitrogen and titanium-nitride is verified using analytical methods. The addition of titanium into the melt can reduce porosity by a factor of three. (C) 2004 Elsevier B.V. All rights reserved.

Nowadays, the complexity of modern telecommunication systems has increased significantly and the requirement for thorough and systematic testing is undisputed. The TTCN-3 is an universal and standardised language for the specification and implementation of tests for communication systems. Many systems and in particular object-oriented systems are described using the UML. Therefore, UML models are an important source for test development and in particular for manual test purpose specification and automatic test generation. Thus, usage of UML from a test perspective is considered.UML models provide interface information by class diagramms and description of scenarios by sequence diagrams respectively MSCs. Most UML tools permit conversion of class diagrams into IDL which widens applicability. The combination of TTCN-3 and UML by MSC and IDL is a new approach. Thus, new mappings for MSC and IDL to TTCN-3 have been worked out. Additionally, to widen usability and applicability, the deficiency of object-orientation in TTCN-3 is inspected and a proposal for an object-oriented revision is given.

An established middleware technology for Internet-based distributed systems is CORBA, where interfaces are described with IDL. TTCN is a standardised test description language widely used in the telecommunications area. The current version of TTCN, version 3 (TTCN-3), is among others designed to test CORBA-based systems.This paper presents a definition of the OMG IDL to TTCN-3 mappings, which facilitate the testing of CORBA-based systems. The application of the mappings is shown by an example test for the CORBA Portable Object Adaptor (POA).

A widely used middleware for Internet based distributed systems is CORBA where interfaces are described with IDL. TTCN is used as a standardised test description language in the telecommunication area. The current version of TTCN, version 3, is among others designed to test CORBA based systems. This requires a mapping of IDL to TTCN-3 and therefore, a new mapping for TTCN-3 in contrast to the existing one for TTCN-2 gets necessary. This paper points out the new features of the TTCN-3 standard and how they can be used for an improved IDL mapping.

Testing of telecommunication systems is a major concern in industry and standar- dization. Therefore, the two major SDL tool vendors have integrated automatic test generation tools into their software development suites. While Telelogic has added Autolink to the Tau tools, former Verilog has extended ObjectGeode with TestComposer. Even though both tools are based on the same concepts, many features are realized dierently and their focus is put onto dierent aspects of the test generation process. This paper introduces the major principles of SDL-based test generation and provides an overview of how both tools support test development.

In many cases users of mobile computers wish to have the same applications running and to have access to the same information as they would when connected to a fixed network. Such transparency is difficult to realise given the differences in the fundamental characteristics of wired and wireless links. These differences, apparent in variations in parameters such as delay, throughput and error rate can have a significant impact on demanding applications such as those which exploit multimedia communications. To overcome these problems, application requirements have to be adapted to match the capabilities of the wireless communication link. One general method of achieving this is the introduction of one or more proxies between the distributed components. This paper presents a generalised architecture for installing and managing proxies in the network in order to enable applications to continue operation in the face of variations in quality of service. The developed architecture is based on the CORBA standard to improve flexibility and acceptance.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Regio- and stereoselective enzymatic glucosylation of 5-azido-5-deoxy-d-fructopyranose with the aid of commerically available α-glucosidase from yeast allows easy access to the corresponding 4-O-α-d-glucopyranosyl derivative of this non-natural ketose. This disaccharide gives, in one step, access to 2,5-dideoxy-3-O-α-d-glucopyranosyl-2,5-imino-d-mannitol.

Immobilised glucose isomerase (EC 5.3.1.5) accepted various (2R,3R)-configured aldofuranoses such as d-erythrose, as well as homologous C-5-modified d-ribose derivatives, as substrates. In the case of d-crythrose, quantitative conversion into d-glycero-tetrulose took place. d-Ribofuranoses were converted into the corresponding open-chain 2-ketoses in isolated yields of 65%. Surprisingly, l-crythrose also turned out to be a substrate of this enzyme.

The properties of glucose isomerase (EC 5.3.1.5) and its synthetic applications are briefly reviewed and recent results with non-natural substrates are discussed. Commercially available immobilized glucose isomerase from Streptomyces murinus, previously discovered to accept D-glucose as well as D-fructose derivatives with modifications at C-3, C-5, and C-6, was also found to be an efficient catalyst for the conversion of 5,6-dimodified derivatives of D-glucose as well as 5-modified D-xylofuranose into the corresponding open-chain 2-ketoses. The equilibrium mixture in all but one case investigated favoured the respective ketose in ratios of 3:1 to 4:1. These results are in agreement with molecular modelling experiments suggesting that the free energies of the furanoid aldoses serving as starting materials are generally slightly higher than the values for the corresponding open-chain ketose. Dimerisation of the open-chain sugar derivatives was not observed.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCyanide as an efficient and mild catalyst in the aminolysis of estersThomas Hoegberg, Peter Stroem, Michael Ebner, and Sten RaemsbyCite this: J. Org. Chem. 1987, 52, 10, 2033–2036Publication Date (Print):May 1, 1987Publication History Published online1 May 2002Published inissue 1 May 1987https://pubs.acs.org/doi/10.1021/jo00386a025https://doi.org/10.1021/jo00386a025research-articleACS PublicationsRequest reuse permissionsArticle Views4494Altmetric-Citations116LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts